Gynecology_Novak

Gynecology_Novak. Table 22.7 Antibiotic Prophylaxis Regimens by Procedure aAlternatives include cefotetan, cefoxitin, cefuroxime, or ampicillin-sulbactam.bA 2-g dose is recommended in women with a body mass index greater than 35 or weight greater than 100 kg or 220 lb. cAntimicrobial agents of choice in women with a history of immediate hypersensitivity to penicillin.dCiproﬂoxacin or levoﬂoxacin or moxiﬂoxacin. eIf patient has a history of pelvic inﬂammatory disease or procedure demonstrates dilated fallopian tubes. No prophylaxis is indicated for a study without dilated tubes. Adapted from Antibiotic prophylaxis for gynecologic procedures. American College of Obstetricians and Gynecologists Practice Bulletin No. 104, May 2009.


Gynecology_Novak

Gynecology_Novak. using proper aseptic technique, minimizing tissue trauma, minimizing the amount foreign material in the surgical site, controlling diabetes, avoiding immunologic suppression, maximizing tissue oxygenation, draining blood and serum from the surgical site, and using prophylactic antibiotics. Antibiotic prophylaxis is given with the belief that antibiotics enhance the immune mechanisms in host tissues that resist infections by killing the bacteria that inoculate the surgical site during surgery (65). Infections in the skin or pelvis that result from gynecologic surgery (e.g., parametritis, cuff cellulitis, pelvic abscess) typically are polymicrobial in nature. These infections are complex and often involve gram-negative rods, gram-positive cocci, and anaerobes. Antibiotic prophylaxis should be sufficiently broad to cover these potential pathogens (66) (Table 22.7).


Gynecology_Novak

Gynecology_Novak. The timing of antimicrobial prophylaxis is important. There is a relatively narrow window of opportunity for affecting outcomes (67). In the United States, it is customary to give antimicrobial prophylaxis shortly before or during the induction of anesthesia. Data revealed that a delay of 3 hours or more between the time of bacterial inoculation (i.e., skin incision) and administration of antibiotics may result in ineffective prophylaxis. Evidence indicates that for prophylaxis, one dose of antibiotic is appropriate. When the surgical procedure proceeds longer than 1 to 2 times the half-life of the drug or blood loss is greater than 1.5 L, additional intraoperative doses of antibiotics should be administered to maintain adequate levels of medication in serum and tissues (68,69). There are no data to support the continuation of prophylactic antimicrobial agents into the postoperative period for routine gynecologic procedures. For cases involving colorectal resection, a reduction in


Gynecology_Novak

Gynecology_Novak. are no data to support the continuation of prophylactic antimicrobial agents into the postoperative period for routine gynecologic procedures. For cases involving colorectal resection, a reduction in surgical site infections (SSI) was seen when antibiotics were continued for up to 24 hours. Other measures to reduce SSI incidence were taken, including tight glycemic control, maintenance of intraoperative normothermia, and placement of subcutaneous drains in obese patients (70).


Gynecology_Novak

Gynecology_Novak. Cephalosporins emerged as the most important class of antimicrobial agents for prophylaxis. These drugs have a broad spectrum and relatively low incidence of adverse reactions. Cefazolin (1 g) appears to be widely used in the United States by gynecologic surgeons because of its relatively low cost and long half-life (1.8 hours). Other cephalosporins such as cefoxitin, cefotaxime, and cefotetan commonly are used for prophylaxis. These agents appear to have a broader spectrum of activity against anaerobic bacteria and are appropriate selections when colorectal resections are possible, such as during a debulking surgery for ovarian cancer. For the majority of gynecologic procedures, there is little evidence that a clinically relevant distinction exists between cefazolin and the other agents. Morbidly obese patients, defined as having a BMI greater than 35 or weight greater than 100kg, should receive2gof cefazolin to achieve appropriate blood and tissue antibiotic concentrations (71).


Gynecology_Novak

Gynecology_Novak. Antimicrobial prophylaxis, although usually beneficial, is not without risk. Anaphylaxis is the most life-threatening complication from antibiotic use. Anaphylactic reactions to penicillins are reported in 0.2% courses of treatment. The fatality rate is 0.0001%. Data indicate that it is safe to administer cephalosporins to women who report a history of adverse reactions to penicillins. The incidence of adverse reactions (e.g., skin ﬂushing, itching) in women with a history of penicillin allergy who are given cephalosporins is 1% to 10%. The incidence of anaphylaxis in this setting is less than 0.02% (72).


Gynecology_Novak

Gynecology_Novak. A single dose of broad-spectrum antibiotics can result in pseudomembranous colitis, caused by Clostridium difficile. Diarrhea may develop in as many as 15% of hospitalized patients treated with beta-lactam antibiotics (73). In patients receiving clindamycin, the rate of diarrhea is nearly 10% to 25% (74). These gastrointestinal complications from antibiotics may cause serious morbidity in the surgical patient, and the surgeon should be able to recognize and manage these problems.


Gynecology_Novak

Gynecology_Novak. Not all gynecologic surgery patients need to receive prophylactic antibiotics. The surgeon should choose agents to cover procedures based on available data, thereby avoiding the potential for adverse reactions and minimizing the unnecessary use of antibiotics, which may contribute to increased rates of antimicrobial resistance. In patients with cephalosporin allergies or anaphylaxis to penicillin, other drugs or combinations should be chosen to provide adequate prophylactic coverage. Antimicrobial prophylaxis options for common gynecologic procedures are presented in Table 22.6. Antibiotic prophylaxis is not indicated for diagnostic or operative laparoscopy, exploratory laparotomy, or diagnostic or operative hysteroscopy, including endometrial ablation, intrauterine device insertions, endometrial biopsy, or urodynamics (75).


Gynecology_Novak

Gynecology_Novak. It was thought that women who had severe valvular disease or other cardiac conditions required antibiotic prophylaxis prior to genitourinary (GU) or gastrointestinal (GI) procedures in order to prevent bacterial endocarditis as a result of the transient bacteremia provoked by the surgery. After reviewing the pertinent evidence-based literature, the American Heart Association issued revised guidelines in 2007 stating that antibiotic prophylaxis was not necessary solely to prevent endocarditis in patients undergoing GI or GU procedures, including hysterectomy (Table 22.8) (76). Table 22.8 Recommendations for Prophylaxis of Bacterial Endocarditis


Gynecology_Novak

Gynecology_Novak. Table 22.8 Recommendations for Prophylaxis of Bacterial Endocarditis IM, intramuscularly; IV, intravenously. Derived from Wilson W, Taubert KA, Gewitz M, et al. Prevention of infective endocarditis: guidelines from the American Heart Association: a guideline from the American Heart Association Rheumatic Fever, Endocarditis, and Kawasaki Disease Committee, Council on Cardiovascular Disease in the Young, and the Council on Clinical Cardiology, Council on Cardiovascular Surgery and Anesthesia, and the Quality of Care and Outcomes Research Interdisciplinary Working Group. Circulation 2007;116:1736–1754.


Gynecology_Novak

Gynecology_Novak. Infections are a major source of morbidity in the postoperative period. Risk factors for infectious morbidity include the absence of perioperative antibiotic prophylaxis, contamination of the surgical field from infected tissues or from spillage of large bowel contents, an immunocompromised host, poor nutrition, chronic and debilitating severe illness, poor surgical technique, and preexisting focal or systemic infection. Sources of postoperative infection can include the lung, urinary tract, surgical site, pelvic sidewall, vaginal cuff, abdominal wound, and sites of indwelling intravenous catheters. Early identification and treatment of infection will result in the best outcome for these potentially serious complications.


Gynecology_Novak

Gynecology_Novak. Although infectious morbidity is an inevitable complication of surgery, the incidence of infections can be decreased by the appropriate use of simple preventive measures. In cases that involve transection of the large bowel, spillage of fecal contents inevitably occurs. A thorough preoperative mechanical and antibiotic bowel preparation in combination with systemic antibiotic prophylaxis will help decrease the incidence of postoperative pelvic and abdominal infections in these patients. The surgeon can further decrease the risk of postoperative infections by using meticulous surgical technique. Blood and necrotic tissue are excellent media for the growth of aerobic and anaerobic organisms. In cases in which there is higher-than-usual potential for serum and blood to collect in spaces that were contaminated by bacterial spill, closed-suction drainage may reduce the risk of infection. Antibiotic therapy, rather than prophylaxis, should be initiated during surgery in patients who have


Gynecology_Novak

Gynecology_Novak. were contaminated by bacterial spill, closed-suction drainage may reduce the risk of infection. Antibiotic therapy, rather than prophylaxis, should be initiated during surgery in patients who have frank intra-abdominal infection or pus. Elective surgical procedures should be postponed in patients who have preoperative infections. In an epidemiologic study conducted by the Centers for Disease Control and Prevention (CDC), the incidence of nosocomial surgical infections ranged from 4.3% in community hospitals to 7% in municipal hospitals (77). Data confirmed this, with an incidence of 2% to 5% (78). Urinary tract infections accounted for approximately 40% of these nosocomial infections. Infections of the skin and wound accounted for approximately one-third of the infections, and respiratory tract infections accounted for approximately 16%. In patients who had any type of infection before surgery, the risk of infection at the surgical wound site increased fourfold. Rates of infection


Gynecology_Novak

Gynecology_Novak. tract infections accounted for approximately 16%. In patients who had any type of infection before surgery, the risk of infection at the surgical wound site increased fourfold. Rates of infection were higher in older patients, in patients with increased length of surgery, and in those with increased length of hospital stay before surgery. The relative risk was three times higher in patients with a community-acquired infection before surgery. These community-acquired infections included infections of the urinary and respiratory tracts.


Gynecology_Novak

Gynecology_Novak. Historically, the standard definition of febrile morbidity for surgical patients was the presence of a temperature higher than or equal to 100.4◦F (38◦C) on two occasions at least 4 hours apart during the postoperative period, excluding the first 24 hours. Other sources defined fever as two consecutive temperature elevations greater than 101.0◦F (38.3◦C) (79,80). Febrile morbidity is estimated to occur in as many as one-half of patients; it is often self-limited, resolves without therapy, and is usually noninfectious in origin (81). Overzealous evaluations of postoperative fever, especially during the early postoperative period, are time consuming, expensive, and sometimes uncomfortable for the patient (81). The value of 101.0◦F is more useful than 100.4◦F to distinguish an infectious cause from an inconsequential postoperative fever.


Gynecology_Novak

Gynecology_Novak. The assessment of a febrile surgical patient should include a review of the patient’s history with regard to risk factors. Both the history and the physical examination should focus on the potential sites of infection (Table 22.9). The examination should include inspection of the pharynx, a thorough pulmonary examination, percussion of the kidneys to assess for costovertebral angle tenderness, inspection and palpation of the abdominal incision, examination of sites of intravenous catheters, and an examination of the extremities for evidence of deep venous thrombosis or thrombophlebitis. In gynecologic patients, an appropriate workup may include inspection and palpation of the vaginal cuff for signs of induration, tenderness, or purulent drainage. A pelvic examination should be performed to identify a mass consistent with a pelvic hematoma or abscess and to look for signs of pelvic cellulitis.


Gynecology_Novak

Gynecology_Novak. Patients with fever in the early postoperative period should have an aggressive pulmonary toilet, including incentive spirometry (80). If the fever persists beyond 72 hours postoperatively, additional laboratory and radiologic data may be obtained. The evaluation may include complete and differential white blood cell counts and a urinalysis. In one study, results from fever workups included positive blood cultures in 9.7% of patients, a positive urine culture in 18.8%, and a positive chest x-ray in 14%. These data support the need for a tailored workup based on the patient’s clinical picture (82). Blood cultures can be obtained but will most likely be of little yield unless the patient has a high fever (102◦F). In patients with costovertebral angle tenderness, intravenous pyelogram may be indicated to rule out the presence of ureteral damage or obstruction from surgery, particularly in the absence of laboratory evidence of urinary tract infection. Patients who have persistent fevers


Gynecology_Novak

Gynecology_Novak. indicated to rule out the presence of ureteral damage or obstruction from surgery, particularly in the absence of laboratory evidence of urinary tract infection. Patients who have persistent fevers without a clear localizing source should undergo CT scanning of the abdomen and pelvis to rule out the presence of an intra-abdominal abscess. If fever persists in patients who had gastrointestinal surgery, a barium enema or upper gastrointestinal studies with small bowel assessment may be indicated late in the course of the first postoperative week to rule out an anastomotic leak or fistula.


Gynecology_Novak

Gynecology_Novak. Table 22.9 Posthysterectomy Infections Urinary Tract Infections Historically, the urinary tract was the most common site of infection in surgical patients (83). The incidence reported in the gynecologic literature is less than 4% (84,85). This decrease in urinary tract infections is most likely the result of increased perioperative use of prophylactic antibiotics. The incidence of postoperative urinary tract infection in gynecologic surgical patients not receiving prophylactic antibiotics is confirmed to be as high as 40%, and even a single dose of perioperative prophylactic antibiotic decreases the incidence of postoperative urinary tract infection to as low as 4% (86,87).


Gynecology_Novak

Gynecology_Novak. Symptoms of a urinary tract infection may include urinary frequency, urgency, and dysuria. In patients with pyelonephritis, other symptoms include headache, malaise, nausea, and vomiting. A urinary tract infection is diagnosed on the basis of microbiology and is defined as the growth of 105 organisms per milliliter of urine cultured. Most infections are caused by coliform bacteria, with Escherichia coli being the most frequent pathogen. Other pathogens include Klebsiella, Proteus, and Enterobacter species. Staphylococcus organisms are the causative bacteria in fewer than 10% of cases.


Gynecology_Novak

Gynecology_Novak. Despite the high incidence of urinary tract infections in the postoperative period, few of these infections are serious. Most are confined to the lower urinary tract, and pyelonephritis is a rare complication (88). Catheterization of the urinary tract, either intermittently or continuously with the use of an indwelling catheter, is implicated as a main cause of urinary tract contamination (89). More than 1 million catheter-associated urinary tract infections occur yearly in the United States, and catheter-associated bacteria remains the most common etiology of gram-negative bacteremia in hospitalized patients. Bacteria adhere to the surface of urinary catheters and grow within bile films, which appear to protect embedded bacteria from antibiotics, making treatment less effective. The use of urinary tract catheters should be minimized. An indwelling catheter should be removed or replaced in a patient undergoing treatment for catheter-related infections.


Gynecology_Novak

Gynecology_Novak. The treatment of urinary tract infection includes hydration and antibiotic therapy. Commonly prescribed and effective antibiotics include penicillin, sulfonamides, cephalosporins, ﬂuoroquinolones, and nitrofurantoin. The choice of antibiotic should be based on knowledge of the susceptibility of organisms cultured at a particular institution. In some institutions, for example, more than 40% of E. coli strains are resistant to ampicillin. For uncomplicated urinary tract infections, an antibiotic that has good activity against E. coli should be given in the interim while awaiting results of the urine culture and sensitivity data.


Gynecology_Novak

Gynecology_Novak. Patients who have a history of recurrent urinary tract infections, those with chronic indwelling catheters (Foley catheters or ureteral stents), and those who have urinary conduits should be treated with antibiotics that will be effective against the less common urinary pathogens such as Klebsiella and Pseudomonas. Chronic use of ﬂuoroquinolones for prophylaxis is not advised because these agents are notorious for inducing antibiotic-resistant strains of bacteria.


Gynecology_Novak

Gynecology_Novak. Pulmonary Infections The respiratory tract is an uncommon site for infectious complications in gynecologic surgical patients. In one study only six cases of pneumonia occurred in more than 4,000 women who underwent elective hysterectomy (85). This low incidence is probably a reﬂection of the young age and good health status of gynecologic patients in general. In acute care facilities, pneumonia is a frequent hospital-acquired infection, particularly in elderly patients (90). Risk factors include extensive or prolonged atelectasis, preexistent COPD, severe or debilitating illness, central neurologic disease causing an inability to clear oropharyngeal secretions effectively, nasogastric suction, and a prior history of pneumonia (90,91). In surgical patients, early ambulation and aggressive management of atelectasis are the most important preventive measures. The role of prophylactic antibiotics remains unclear.


Gynecology_Novak

Gynecology_Novak. A significant percentage (40% to 50%) of cases of hospital-acquired pneumonia is caused by gram-negative organisms (83). These organisms gain access to the respiratory tract from the oral pharynx. Gram-negative colonization of the oral pharynx is increased in patients in acute care facilities and is associated with the presence of nasogastric tubes, preexisting respiratory disease, mechanical ventilation, and tracheal intubation (92). The use of antimicrobial drugs seems to significantly increase the frequency of colonization of the oral pharynx with gram-negative bacteria.


Gynecology_Novak

Gynecology_Novak. A thorough lung examination should be included in the assessment of all febrile surgical patients. In the absence of significant lung findings, chest radiography is probably of little benefit in patients at low risk for postoperative pulmonary complications. In patients with pulmonary findings or with risk factors for pulmonary complications, chest radiography should be performed. A sputum sample should be obtained for Gram stain and culture. The treatment should include postural drainage, aggressive pulmonary toilet, and antibiotics. The antibiotic chosen should be effective against both gram-positive and gram-negative organisms. In patients who are receiving assisted ventilation, the antibiotic spectrum should include drugs that are active against Pseudomonas organisms.


Gynecology_Novak

Gynecology_Novak. Phlebitis Historically, intravenous catheter–related infections were common; the reported incidence is 25% to 35% in the 1980s (93). Because the incidence of catheter-related phlebitis increases significantly after 72 hours, intravenous catheters should be changed at least every 3 days according to the CDC (94). The institution of intravenous therapy teams decreased the incidence of phlebitis by as much as 50% in one study (95). In combination, these measures led to a dramatic decrease in peripheral catheter site infection.


Gynecology_Novak

Gynecology_Novak. The intravenous site should be inspected daily, and the catheter should be removed if there is any associated pain, redness, or induration. Phlebitis can occur even with close surveillance of the intravenous site. In one study, more than 50% of the cases of phlebitis became evident more than 12 hours after discontinuation of intravenous catheters (96). Less than one-third of patients had symptoms related to the intravenous catheter site 24 hours before the diagnosis of phlebitis. Phlebitis can be diagnosed based on the presence of fever, pain, redness, induration, or a palpable venous cord. Occasionally, suppuration will be present. Phlebitis is usually self-limited and resolves within 3 to 4 days. The treatment includes application of warm, moist compresses and prompt removal of any catheters from the infected vein. Antibiotic therapy with antistaphylococcal agents should be instituted for catheter-related sepsis. Excision or drainage of an infected vein rarely is necessary.


Gynecology_Novak

Gynecology_Novak. Wound Infections The results of a prospective study of more than 62,000 wounds were revealing in regard to the epidemiology of wound infections (97). The wound infection rate varied markedly, depending on the extent of contamination of the surgical field. The wound infection rate for clean surgical cases (infection not present in the surgical field, no break in aseptic technique, no viscus entered) was lower than 2%, whereas the incidence of wound infections with dirty, infected cases was 40% or higher. Preoperative showers with hexachlorophene slightly lowered the infection rate for clean wounds, whereas preoperative shaving of the wound site with a razor increased the infection rate. A 5-minute wound preparation immediately before surgery was as effective as preparation for 10 minutes. The wound infection rate increased with the duration of preoperative hospital stay and with the duration of surgery. Incidental appendectomy increased the risk of wound infection in patients


Gynecology_Novak

Gynecology_Novak. minutes. The wound infection rate increased with the duration of preoperative hospital stay and with the duration of surgery. Incidental appendectomy increased the risk of wound infection in patients undergoing clean surgical procedures. The study concluded that the incidence of wound infections could be decreased by short preoperative hospital stays, hexachlorophene showers before surgery, minimizing shaving of the wound site, use of meticulous surgical technique, decreasing operative time as much as possible, bringing drains out through sites other than the wound, and dissemination of information to surgeons regarding their wound infection rates. A program instituting these conclusions led to a decrease in the clean wound infection rate from 2.5% to 0.6% over an 8-year period. The wound infection rate in most gynecologic services is lower than 5%, reﬂective of the clean nature of most gynecologic operations.


Gynecology_Novak

Gynecology_Novak. The symptoms of wound infection often occur late in the postoperative period, usually after the fourth postoperative day, and may include fever, erythema, tenderness, induration, and purulent drainage. Wound infections that occur on postoperative days 1 through 3 are generally caused by streptococcal and Clostridia infections. The management of wound infections is mostly mechanical and involves opening the infected portion of the wound above the fascia, with cleansing and debridement of the wound edges as necessary. Wound care, consisting of debridement and dressing changes two to three times daily with mesh gauze, will promote growth of granulation tissue, with gradual filling in of the wound defect by secondary intention. Clean, granulating wounds can often be secondarily closed with good success, shortening the time required for complete wound healing.


Gynecology_Novak

Gynecology_Novak. The technique of delayed primary wound closure can be used in contaminated surgical cases to lower the incidence of wound infection. This technique involves leaving the wound open above the fascia at the time of the initial surgical procedure. Vertical interrupted mattress sutures through the skin and subcutaneous layers are placed 3 cm apart but are not tied. Wound care is instituted immediately after surgery and continued until the wound is noted to be granulating well. Sutures may then be tied and the skin edges further approximated using sutures or staples. Using this technique of delayed primary wound closure, the overall wound infection rate is decreased from 23% to 2.1% in high-risk patients (98).


Gynecology_Novak

Gynecology_Novak. Pelvic Cellulitis Vaginal cuff cellulitis is present in most patients who underwent hysterectomy. It is characterized by erythema, induration, and tenderness at the vaginal cuff. A purulent discharge from the apex of the vagina may be present. The cellulitis is often self-limited and does not require any treatment. Fever, leukocytosis, and pain localized to the pelvis may accompany severe cuff cellulitis and most often signifies extension of the cellulitis to adjacent pelvic tissues. In such cases, broad-spectrum antibiotic therapy should be instituted with coverage for gram-negative, gram-positive, and anaerobic organisms. If purulence at the vaginal cuff is excessive or if there is a ﬂuctuant mass noted at the vaginal cuff, the vaginal cuff should be gently probed and opened with a blunt instrument. The cuff can be left open for dependent drainage or, alternatively, a drain can be placed into the lower pelvis through the cuff and removed when drainage, fever, and symptoms in the


Gynecology_Novak

Gynecology_Novak. instrument. The cuff can be left open for dependent drainage or, alternatively, a drain can be placed into the lower pelvis through the cuff and removed when drainage, fever, and symptoms in the lower pelvic region have resolved.


Gynecology_Novak

Gynecology_Novak. Intra-abdominal and The development of an abscess in the surgical field or elsewhere in the abdominal cavity is Pelvic Abscess an uncommon complication after a gynecologic surgery. It is likely to occur in contaminated cases in which the surgical site is not adequately drained or as a secondary complication of hematomas. The causative pathogens in patients who have intra-abdominal abscesses are usually polymicrobial in nature. The aerobes most commonly identified include E. coli, Klebsiella, Streptococcus, Proteus, and Enterobacter. Anaerobic isolates are common, usually from the Bacteroides group. These pathogens arise mainly from the vaginal tract but can be derived from the gastrointestinal tract, particularly when the colon was entered at the time of surgery.


Gynecology_Novak

Gynecology_Novak. Intra-abdominal abscess is sometimes difficult to diagnose. The evolving clinical picture is often one of persistent febrile episodes with a rising white blood cell count. Findings on abdominal examination may be equivocal. If an abscess is located deep in the pelvis, it may be palpable by pelvic or rectal examination. For abscesses above the pelvis, the diagnosis will depend on radiologic confirmation. Ultrasonography can occasionally delineate ﬂuid collections in the upper abdomen and in the pelvis. Bowel gas interference makes visualization of ﬂuid collections or abscesses in the midabdomen difficult to distinguish. Computed tomography scanning is more sensitive and specific for diagnosing intra-abdominal abscesses and often is the radiologic procedure of choice. Occasionally, if conventional radiologic methods fail to identify an abscess and the index of suspicion for an abscess remains high, labeled leukocyte scanning may be useful for locating the infected focus.


Gynecology_Novak

Gynecology_Novak. Standard therapy for intra-abdominal abscess is evacuation and drainage combined with appropriate parenteral administration of antibiotics. Abscesses located low in the pelvis, particularly in the area of the vaginal cuff, can be reached through a vaginal approach. In many patients, the ability to drain an abscess by placement of a drain percutaneously under CT guidance obviated the need for surgical exploration. With CT guidance, a pigtail catheter is placed into an abscess cavity via transperineal, transrectal, or transvaginal approaches. The catheter is left in place until drainage decreases. Transperineal and transrectal drainage of deep pelvic abscesses is successful in 90% to 93% of patients, obviating the need for surgical management (99,100).


Gynecology_Novak

Gynecology_Novak. For those patients in whom radiologic drainage is not successful, surgical exploration and evacuation are indicated. The standard approach to initial antibiotic therapy is the combination of ampicillin, gentamicin, and clindamycin. Adequate treatment can be achieved with available broad-spectrum single agents (including the broad-spectrum penicillin), second-and third-generation cephalosporins, levoﬂoxacin and metronidazole, and the sulbactam-clavulanic acid–containing preparations (101).


Gynecology_Novak

Gynecology_Novak. Necrotizing Fasciitis Necrotizing fasciitis is an uncommon infectious disorder, affecting roughly 1,000 patients per year (102). This disease process is characterized by a rapidly progressive bacterial infection that involves the subcutaneous tissues and fascia while characteristically sparing underlying muscle. Systemic toxicity is a frequent feature of this disease, as manifested by the presence of dehydration, septic shock, disseminated intravascular coagulation, and multiple organ system failure.


Gynecology_Novak

Gynecology_Novak. The pathogenesis of necrotizing fasciitis involves a polymicrobial infection of the dermis and subcutaneous tissue. Hemolytic streptococcus was initially believed to be the primary pathogen responsible for the infection in necrotizing fasciitis (103). Other organisms are often cultured in addition to streptococcus, including other gram-positive organisms, coliforms, and anaerobes (104). Bacterial enzymes such as hyaluronidase and lipase released in the subcutaneous space destroy the fascia and adipose tissue and induce a liquefactive necrosis. Noninﬂammatory intravascular coagulation or thrombosis subsequently occurs. Intravascular coagulation results in ischemia and necrosis of the subcutaneous tissues and skin. Subcutaneous spread of up to 1 inch per hour can be seen, often with little effect on the overlying skin (104). Late in the course of the infection, destruction of the superficial nerves produces anesthesia in the involved skin. The release of bacteria and bacterial toxins


Gynecology_Novak

Gynecology_Novak. effect on the overlying skin (104). Late in the course of the infection, destruction of the superficial nerves produces anesthesia in the involved skin. The release of bacteria and bacterial toxins into the systemic circulation can cause septic shock, acid-base disturbances, and multiple organ impairment.


Gynecology_Novak

Gynecology_Novak. The diagnosis is often difficult to make early in the disease course. Most patients with necrotizing fasciitis develop erythema, edema, and pain, which in the early stages of the disease is disproportionately greater than that expected from the degree of cellulitis present and characteristically extends beyond the border of erythema (105). Late in the course of the infection, the involved skin may be anesthetized secondary to necrosis of superficial nerves. Temperature abnormalities, both hyperthermia and hypothermia, are concomitant with the release of bacterial toxins and with bacterial sepsis (104). The involved skin is initially tender, erythematous, and warm. Edema develops, and the erythema spreads diffusely, fading into normal skin, characteristically without distinct margins or induration. Subcutaneous microvascular thrombosis induces ischemia in the skin, which becomes cyanotic and blistered. As necrosis develops, the skin becomes gangrenous and may slough spontaneously


Gynecology_Novak

Gynecology_Novak. or induration. Subcutaneous microvascular thrombosis induces ischemia in the skin, which becomes cyanotic and blistered. As necrosis develops, the skin becomes gangrenous and may slough spontaneously (104). Most patients will have leukocytosis and acid-base abnormalities. Subcutaneous gas may develop, which can be identified by palpation and by radiography. The finding of subcutaneous gas by radiography is often indicative of clostridial infection, although it is not a specific finding and may be caused by other organisms. These organisms include Enterobacter, Pseudomonas, anaerobic streptococci, and Bacteroides, which, unlike clostridial infections, spare the muscles underlying the affected area. A tissue biopsy specimen for Gram stain and aerobic and anaerobic culture should be obtained from the necrotic center of the lesion to identify the etiologic organisms (105). Although necrotizing fasciitis often is diagnosed during surgery, a high index of suspicion and liberal use of


Gynecology_Novak

Gynecology_Novak. from the necrotic center of the lesion to identify the etiologic organisms (105). Although necrotizing fasciitis often is diagnosed during surgery, a high index of suspicion and liberal use of frozen-section biopsy can provide an early life-saving diagnosis and minimize morbidity (104).


Gynecology_Novak

Gynecology_Novak. Predisposing risk factors for necrotizing fasciitis include diabetes mellitus, alcoholism, an immunocompromised state, hypertension, peripheral vascular disease, intravenous drug abuse, and obesity (104). The most frequent site of infection is in the extremities, but the infection can occur anywhere in the subcutaneous tissues, including the head and neck, trunk, and perineum. Necrotizing fasciitis occurs after trauma, surgery, burns, and lacerations; as a secondary complication in perirectal infections or Bartholin duct abscesses; and de novo (103,106– 109). Increased age, delay in diagnosis, inadequate debridement during initial surgery, extensive disease at the time of diagnosis, and the presence of diabetes mellitus are all factors that are associated with an increased likelihood of mortality from necrotizing fasciitis (104–106). Early diagnosis and aggressive management of this lethal disease contribute to improved survival.


Gynecology_Novak

Gynecology_Novak. Successful management of necrotizing fasciitis involves early recognition, immediate initiation of resuscitative measures (including correction of ﬂuid, acid-base, electrolyte, and hematologic abnormalities), aggressive surgical debridement and redebridement as necessary, and broad-spectrum intravenous antibiotic therapy (104). During surgery, the incision should be made through the infected tissue down to the fascia. An ability to undermine the skin and subcutaneous tissues with digital palpation often will confirm the diagnosis. Multiple incisions can be made sequentially toward the periphery of the affected tissue until well-vascularized, healthy, resistant tissue is reached at all margins. The remaining affected tissue must be excised. The wound can be packed and sequentially debrided on a daily basis as necessary until healthy tissue is displayed at all margins. Hyperbaric oxygen therapy may be of some benefit, particularly in patients for whom culture results are positive for


Gynecology_Novak

Gynecology_Novak. on a daily basis as necessary until healthy tissue is displayed at all margins. Hyperbaric oxygen therapy may be of some benefit, particularly in patients for whom culture results are positive for anaerobic organisms (110). Retrospective nonrandomized studies demonstrated that the addition of hyperbaric oxygen therapy to surgical debridement and antimicrobial therapy appears to significantly decrease both wound morbidity and overall mortality in patients with necrotizing fasciitis (110). The benefit of hyperbaric therapy demonstrated in one study was remarkable, given that patients receiving hyperbaric oxygen were sicker and had a higher incidence of diabetes mellitus, leukocytosis, and shock (106).


Gynecology_Novak

Gynecology_Novak. After the initial resuscitative efforts and surgical debridement, the primary concern is the management of the open wound. Allograft and xenograft skin can be used to cover open wounds, thus decreasing heat and evaporative water loss. Temporary biologic closure of open wounds seems to decrease bacterial growth (111). Amniotic membranes were effective wound covering in patients with necrotizing fasciitis (112). A new technology demonstrated to significantly improve wound healing in laboratory and clinical studies is a vacuum-assisted closure (VAC) method that uses a subatmospheric pressure technique (113–115). In situations in which spontaneous closure is not likely, the VAC device may allow for the development of a suitable granulation bed and prepare the tissue for graft placement, thereby increasing the probability of graft survival. Skin ﬂaps can be mobilized to help cover open wounds when the infections resolve and granulation begins.


Gynecology_Novak

Gynecology_Novak. Traditionally, mechanical bowel preparation was advised before abdominal surgery, especially if colonic surgery was anticipated. Despite the infrequent need for colonic surgery (or injury) when performing gynecologic surgery, bowel preparation is part of the standard practice for many gynecologists. Advantages of mechanical bowel preparation include reduction of gastrointestinal contents, which facilitates the surgical procedure by allowing more room in the abdomen and pelvis. If a rectosigmoid colon enterotomy occurs, the mechanical bowel preparation eliminates formed stool and reduces the risk of bacterial contamination, thus reducing infectious complications.


Gynecology_Novak

Gynecology_Novak. Randomized clinical trials questioned the need for mechanical bowel preparation in colonic surgery (116). Although somewhat controversial, a meta-analyses including almost 5,000 patients showed no statistical difference between the groups for anastomotic leakage (p = 0.46), pelvic or abdominal abscess (p = 0.75), and wound sepsis (p = 0.11). The use of different mechanical regimes did not inﬂuence primary and secondary outcomes. The authors concluded that this analysis demonstrates that any kind of mechanical bowel preparation should be omitted before colonic surgery. The main limitation concerned rectal surgery for which the limited data preclude any interpretation.


Gynecology_Novak

Gynecology_Novak. A randomized trial of mechanical bowel preparation versus no bowel preparation with rectal surgery found that the overall and site-specific infectious morbidity rates were significantly higher in no preparation versus the mechanical preparation group. Regarding anastomotic leakage, length of hospital stay, major morbidity and mortality rates, there was no significant difference between the no preparation and mechanical bowel preparation groups. This was the first randomized trial to demonstrate that rectal cancer surgery without mechanical preparation is associated with higher risk of overall and infectious morbidity rates without any significant increase of anastomotic leakage rate. It suggests continuing to perform mechanical preparation before elective rectal resection for cancer (117).


Gynecology_Novak

Gynecology_Novak. Despite evidence of the infectious complications associated with mechanical preparation or no preparation, many gynecologic surgeons prefer a mechanical preparation to aid with exposure in the pelvic operative field. This may be particularly relevant to the surgeon performing minimally invasive surgery.


Gynecology_Novak

Gynecology_Novak. Mechanical bowel preparation may be accomplished as presented in (Table 22.10). The traditional use of laxatives and enemas requires at least 12 to 24 hours and causes moderate abdominal distention and crampy pain. Randomized trials comparing traditional mechanical bowel preparation (magnesium citrate and enemas) with oral gut lavage (PEG electrolyte solution, GoLYTELY) found that the use of approximately 4 L of GoLYTELY (administered until the rectal efﬂuent is clear) provides more complete, faster, and more comfortable bowel preparation (118). However, the ingestion of 4 L of ﬂuid is problematic for many patients, so magnesium citrate may be preferable when mechanical preparation is to be used.


Gynecology_Novak

Gynecology_Novak. An alternative mechanical preparation method is the use of oral sodium phosphate (Phospho-Soda). When evaluated in a randomized trial comparing the 4 L of GoLYTELY with oral sodium phosphate, colonoscopic examination disclosed that both methods were equally effective in colonic cleansing, and more patients preferred the sodium phosphate method (119). Some patients are at higher risk to develop acute phosphate nephropathy, leading to acute renal failure or worsening of chronic renal disease after the use of sodium phosphate. Although the pathophysiology is not fully understood, it may be secondary to substantial ﬂuid shifts and electrolyte changes. It is speculated that potential etiologic factors included inadequate hydration, increased patient age, a history of hypertension, and current use of an angiotensin receptor Table 22.10 Mechanical Bowel Preparation 4 L of GoLYTELY


Gynecology_Novak

Gynecology_Novak. Table 22.10 Mechanical Bowel Preparation 4 L of GoLYTELY OR Fleet Phospho-Soda Saline laxative (3 oz. bottle)a (one bottle of laxative 1 p.m. and another at 7 p.m.) Fleet enemas until no solid stool in p.m. (optional) Neomycin (oral), 1 g every 4 h for three doses (4, 8, 12 p.m.) Erythromycin (oral), 1 g every 4 h for three doses or metronidazole 500 mgm every 4 h for three doses aBe aware of acute phosphate nephropathy. Avoid use of phospho-soda in patients with inadequate hydration, increased age, a history of hypertension, current use of an angiotensin receptor blocker, or angiotensin-conversing enzyme (ACE) inhibitors; renal disease or chronic heart failure and those taking nonsteroidal anti-inﬂammatory drugs (NSAIDs) or diuretics.


Gynecology_Novak

Gynecology_Novak. blocker or angiotension-converting enzyme (ACE) inhibitors. Patients with chronic renal disease or chronic heart failure and those taking NSAIDs or diuretics appear to be at higher risk of acute phosphate nephropathy (120). For these patients, the guidelines recommend an alternative bowel preparation agent, polyethylene glycol, which is not associated with volume shifts and electrolyte abnormalities (121,122). Oral antibiotic prophylaxis was advised over the past three decades to reduce the infectious complications following colonic surgery. The usual regimen was a combination of oral erythromycin and neomycin taken the day before surgery. Many surgeons would substitute oral metronidazole for erythromycin because patients tolerate it better. With the use of perioperative parental antibiotics, the benefit of oral antibiotics is questioned and most surgeons abandoned the use of oral antibiotics in favor of perioperative parenteral antibiotics.


Gynecology_Novak

Gynecology_Novak. Ileus Following open abdominal or pelvic surgery, most patients experience some degree of intestinal ileus. The exact mechanism by which this arrest and disorganization of gastrointestinal motility occurs is unknown, but it appears to be associated with the opening of the peritoneal cavity and is aggravated by manipulation of the intestinal tract and prolonged surgical procedures. Infection, peritonitis, and electrolyte disturbances may result in ileus. For most patients undergoing common gynecologic operations, the degree of ileus is minimal, and gastrointestinal function returns relatively rapidly, allowing the resumption of oral intake within a few days of surgery. Patients who have persistently diminished bowel sounds, abdominal distention, and nausea and vomiting require further evaluation and more aggressive management. Patients with symptoms of ileus or small bowel obstruction who underwent minimally invasive surgery are a different matter. Minimally invasive surgery should


Gynecology_Novak

Gynecology_Novak. and more aggressive management. Patients with symptoms of ileus or small bowel obstruction who underwent minimally invasive surgery are a different matter. Minimally invasive surgery should result in a daily improvement in GI function. An “ileus” in the case of minimally invasive surgery more likely represents GI injury, which should be evaluated immediately with a CT scan using GI contrast.


Gynecology_Novak

Gynecology_Novak. Ileus is usually manifested by abdominal distention and should be evaluated by physical examination. Pertinent points of the abdominal examination include assessment of the quality of bowel sounds and palpation in search of distension, masses, tenderness, or rebound. The possibility that the patient’s signs and symptoms may be associated with a more serious intestinal obstruction or intestinal complication (such as a perforation) must be considered. Pelvic examination should be performed to evaluate the possibility of a pelvic abscess or hematoma that may contribute to the ileus. Abdominal radiography to evaluate the abdomen in the ﬂat (supine) position and in the upright position will aid in the diagnosis of an ileus. The most common radiographic findings include dilated loops of small and large bowel and air-ﬂuid levels while the patient is in the upright position. Sometimes, massive dilation of the colon or stomach may be noted. The remote possibility of distal colonic obstruction


Gynecology_Novak

Gynecology_Novak. large bowel and air-ﬂuid levels while the patient is in the upright position. Sometimes, massive dilation of the colon or stomach may be noted. The remote possibility of distal colonic obstruction suggested by a dilated cecum should be excluded by rectal examination, proctosigmoidoscopy, colonoscopy, or barium enema. In the postoperative gynecology patient, especially in the upright position, the abdominal x-ray may show free air. This common finding following surgery lasts 7 to 10 days in some instances and is not indicative of a perforated viscus in most patients.


Gynecology_Novak

Gynecology_Novak. The initial management of a postoperative ileus is aimed at gastrointestinal tract decompression and maintenance of appropriate intravenous replacement ﬂuids and electrolytes. 1. The patient should be made NPO status (nothing by mouth) with intravenous (IV) ﬂuids and electrolytes. If nausea and vomiting persist, a nasogastric tube should be used to evacuate the stomach of its ﬂuid and gaseous contents. Continued nasogastric suction removes swallowed air, which is the most common source of gas in the small bowel. 2. Fluid and electrolyte replacement must be adequate to keep the patient well hydrated and in metabolic balance. Significant amounts of third-space ﬂuid loss occur in the bowel wall, the bowel lumen, and the peritoneal cavity during the acute episode. Gastrointestinal ﬂuid losses from the stomach may lead to metabolic alkalosis and depletion of other electrolytes as well. Careful monitoring of serum chemistry levels and appropriate replacement are necessary. 3.


Gynecology_Novak

Gynecology_Novak. 3. Most cases of severe ileus begin to improve over a period of several days. This improvement is recognizable by a reduction in the abdominal distention, return of normal bowel sounds, and passage of ﬂatus or stool. Repeat abdominal radiographs should be obtained as necessary for further monitoring. 4. When the gastrointestinal tract function appears to have returned to normal, the nasogastric tube may be removed and a liquid diet instituted. 5.


Gynecology_Novak

Gynecology_Novak. 4. When the gastrointestinal tract function appears to have returned to normal, the nasogastric tube may be removed and a liquid diet instituted. 5. If a patient shows no evidence of improvement during the first 48 to 72 hours of medical management, other causes of ileus should be sought. Such cases may include ureteral injury, peritonitis from pelvic infection, unrecognized gastrointestinal tract injury with peritoneal spill, or ﬂuid and electrolyte abnormalities such as hypokalemia. With persistent ileus, the use of water-soluble upper gastrointestinal contrast studies (CT scan with oral contrast) may assist in the resolution, but prospective randomized data regarding this maneuver are lacking.


Gynecology_Novak

Gynecology_Novak. Small Bowel Obstruction Obstruction of the small bowel following major gynecologic surgery occurs in approximately 1% to 2% of patients (123). The most common cause of small bowel obstruction is adhesions to the operative site. If the small bowel becomes adherent in a twisted position, partial or complete obstruction may result from distention, ileus, or bowel wall edema. Less common causes of postoperative small bowel obstruction include entrapment of the small bowel into an incisional hernia and an unrecognized defect in the small bowel or large bowel mesentery. Early in its clinical course, a postoperative small bowel obstruction may exhibit signs and symptoms identical to those of ileus. Initial conservative management as outlined for the treatment of ileus is appropriate. Because of the potential for mesenteric vascular occlusion and resulting ischemia or perforation, worsening symptoms of abdominal pain, progressive distention, fever, leukocytosis, or acidosis should be


Gynecology_Novak

Gynecology_Novak. of the potential for mesenteric vascular occlusion and resulting ischemia or perforation, worsening symptoms of abdominal pain, progressive distention, fever, leukocytosis, or acidosis should be evaluated carefully because immediate surgery may be required.


Gynecology_Novak

Gynecology_Novak. In most cases of small bowel obstruction following gynecologic surgery, the obstruction is only partial and the symptoms usually resolve with conservative management. 1. Further evaluation after several days of conservative management may be necessary. Evaluation of the gastrointestinal tract with barium enema, an upper gastrointestinal study, or a CT scan with small bowel assessment is appropriate. In most cases, complete obstruction is not documented, although a narrowing (“transition point”) or tethering of the segment of small bowel may indicate the site of the problem. 2. Further conservative management with nasogastric decompression and intravenous ﬂuid replacement may allow time for bowel wall edema or torsion of the mesentery to resolve. 3. If resolution is prolonged and the patient’s nutritional status is marginal, the use of TPN may be necessary. 4.


Gynecology_Novak

Gynecology_Novak. 3. If resolution is prolonged and the patient’s nutritional status is marginal, the use of TPN may be necessary. 4. Conservative medical management of postoperative small bowel obstruction usually results in complete resolution. If persistent evidence of small bowel obstruction remains after full evaluation and an adequate trial of medical management, exploratory laparotomy may be necessary to manage the obstruction. In most cases, lysis of adhesions is all that is required, although a segment of small bowel that is badly damaged or extensively sclerosed from adhesions may require resection and reanastomosis.


Gynecology_Novak

Gynecology_Novak. Colonic Obstruction Postoperative colonic obstruction following surgery for most gynecologic conditions is exceedingly rare. It is associated with a pelvic malignancy, which in most cases was known at the time of the initial operation. Advanced ovarian carcinoma is the most common cause of colonic obstruction in postoperative gynecologic surgery patients, and it is caused by extrinsic impingement on the colon by the pelvic malignancy. Intrinsic colonic lesions may be undetected, especially in a patient with some other benign gynecologic condition. When colonic obstruction is manifested by abdominal distention and abdominal radiography reveals a dilated colon and enlarging cecum, further evaluation of the large bowel is required by barium enema or colonoscopy. Dilation of the cecum to more than 10 to 12 cm in diameter as viewed by abdominal radiography requires immediate evaluation and surgical decompression by performing colectomy or colostomy. Surgery should be performed as soon as


Gynecology_Novak

Gynecology_Novak. than 10 to 12 cm in diameter as viewed by abdominal radiography requires immediate evaluation and surgical decompression by performing colectomy or colostomy. Surgery should be performed as soon as the obstruction is documented. Conservative management of colonic obstruction is not appropriate because the complication of colonic perforation has an exceedingly high mortality rate. In patients who are too ill to undergo surgery, the interventional radiologist may be able to place a cecostomy tube or the gastroenterologist may place a colonic stent (124).


Gynecology_Novak

Gynecology_Novak. Diarrhea Episodes of diarrhea often occur following abdominal and pelvic surgery as the gastrointestinal tract returns to its normal function and motility. Prolonged and multiple episodes may represent a pathologic process such as impending small bowel obstruction, colonic obstruction, or pseudomembranous colitis. Excessive amounts of diarrhea should be evaluated by abdominal radiography and stool samples tested for the presence of ova and parasites, bacterial culture, and Clostridium difficile toxin. Proctoscopy and colonoscopy may be advisable in severe cases. Evidence of intestinal obstruction should be managed as outlined previously. Infectious causes of diarrhea should be managed with the appropriate antibiotics and ﬂuid and electrolyte replacement. C. difficile–associated pseudomembranous colitis may result from exposure to any antibiotic. Discontinuation of these antibiotics (unless they are needed to treat another severe infection) is advisable, along with the institution of


Gynecology_Novak

Gynecology_Novak. colitis may result from exposure to any antibiotic. Discontinuation of these antibiotics (unless they are needed to treat another severe infection) is advisable, along with the institution of appropriate therapy. Oral metronidazole is a suitable agent for instituting therapy and is less expensive than vancomycin. Therapy should be continued until the diarrhea abates, and several weeks of oral therapy may be required to obtain complete resolution of the pseudomembranous colitis.


Gynecology_Novak

Gynecology_Novak. Fistula Gastrointestinal fistulas are relatively rare following gynecologic surgery. They are most often associated with malignancy, prior radiation therapy, intestinal resection with anastomosis, or surgical injury to the large or small bowel that was improperly repaired or unrecognized. Signs and symptoms of gastrointestinal fistula are often similar to those of small bowel obstruction or ileus, except that fever is usually a more prominent component of the patient’s symptoms. When fever is associated with gastrointestinal dysfunction postoperatively, evaluation should include early assessment of the gastrointestinal tract to confirm its continuity. When fistula is suspected, the use of water-soluble gastrointestinal contrast material is advised to avoid the complication of barium peritonitis. Evaluation with abdominal pelvic CT scan may assist in identification of a fistula and associated abscess. Recognition of an intraperitoneal gastrointestinal leak or fistula formation usually


Gynecology_Novak

Gynecology_Novak. Evaluation with abdominal pelvic CT scan may assist in identification of a fistula and associated abscess. Recognition of an intraperitoneal gastrointestinal leak or fistula formation usually requires immediate surgery, unless the fistula drained spontaneously through the abdominal wall or vaginal cuff.


Gynecology_Novak

Gynecology_Novak. An enterocutaneous fistula arising from the small bowel and draining spontaneously through the abdominal incision may be managed successfully with medical therapy. Therapy should include nasogastric decompression, replacement of intravenous ﬂuids as well as TPN, and appropriate antibiotics to treat an associated mixed bacterial infection. If the infection is under control and there are no other signs of peritonitis, the surgeon may consider allowing potential resolution of the fistula over a period of up to 2 weeks. Some authors suggested the use of somatostatin to decrease intestinal tract secretion and allow earlier healing of the fistula. In some cases, the fistula will close spontaneously with this mode of management. If the enterocutaneous fistula does not close with conservative medical management, surgical correction with resection, bypass, or reanastomosis will be necessary.


Gynecology_Novak

Gynecology_Novak. A rectovaginal fistula that occurs following gynecologic surgery is usually the result of surgical trauma that may have been aggravated by the presence of extensive adhesions and scarring in the rectovaginal septum associated with endometriosis, pelvic inﬂammatory disease, or pelvic malignancy. A small rectovaginal fistula may be managed with a conservative medical approach, in the hope that decreasing the fecal stream will allow closure of the fistula.


Gynecology_Novak

Gynecology_Novak. A small fistula that allows continence except for an occasional leak of ﬂatus may be managed conservatively until the inﬂammatory process in the pelvis resolves. At that point, usually several months later, correction of the fistula is appropriate. Large rectovaginal fistulas for which there is no hope of spontaneous closure are best managed by performing an initial diverting colostomy followed by repair of the fistula after inﬂammation resolves. After the fistula closure is healed and deemed successful, the colostomy can be reversed. Risk Factors Deep venous thrombosis and pulmonary embolism are largely preventable, yet significant complications in postoperative patients. The magnitude of this problem is relevant to the Table 22.11 Thromboembolism Risk Stratification Age <40 years with other risk factorsa and major surgery History of deep venous thrombosis or pulmonary embolism


Gynecology_Novak

Gynecology_Novak. Table 22.11 Thromboembolism Risk Stratification Age <40 years with other risk factorsa and major surgery History of deep venous thrombosis or pulmonary embolism Age >60 and cancer or history of venous thromboembolism aRisk factors: obesity, varicose veins, history of deep venous thrombosis or pulmonary embolism, current estrogen, tamoxifen, or oral contraceptive use. gynecologist, because 40% of all deaths following gynecologic surgery are directly attributed to pulmonary emboli, and it is the most frequent cause of postoperative death in patients with uterine or cervical carcinoma (125,126).


Gynecology_Novak

Gynecology_Novak. The causal factors of venous thrombosis were first proposed by Virchow in 1858 and include a hypercoagulable state, venous stasis, and vessel endothelial injury. Risk factors include major surgery; advanced age; nonwhite race; malignancy; history of deep venous thrombosis, lower extremity edema, or venous stasis changes; presence of varicose veins; being overweight; a history of radiation therapy; and hypercoagulable states, such as factor V Lieden, pregnancy, and use of oral contraceptives, estrogens, or tamoxifen. Intraoperative factors associated with postoperative deep venous thrombosis include increased anesthesia time, increased blood loss, and the need for transfusion in the operating room. It is important to recognize these risk factors and to provide the appropriate level of venous thrombosis prophylaxis (127,128). The levels of thromboembolism risk are listed in Table 22.11.


Gynecology_Novak

Gynecology_Novak. Prophylactic Methods A number of prophylactic methods significantly reduced the incidence of deep venous thrombosis, and a few studies included a large enough patient population to show a reduction in fatal pulmonary emboli (129). The ideal prophylactic method would be effective, free of significant side effects, well accepted by the patient and nursing staff, widely applicable to most patients, and inexpensive. The use of small doses of subcutaneously administered heparin for the prevention of deep venous thrombosis and pulmonary embolism is the most widely studied of all prophylactic methods.


Gynecology_Novak

Gynecology_Novak. The use of small doses of subcutaneously administered heparin for the prevention of deep venous thrombosis and pulmonary embolism is the most widely studied of all prophylactic methods. More than 25 controlled trials demonstrated that heparin given subcutaneously 2 hours preoperatively and every 8 to 12 hours postoperatively is effective in reducing the incidence of deep venous thrombosis. The value of low-dose heparin in preventing fatal pulmonary emboli was established by a randomized, controlled multicenter international trial, which demonstrated a significant reduction in fatal postoperative pulmonary emboli in general surgery patients receiving low-dose heparin every 8 hours postoperatively (129). Trials of low-dose heparin in gynecologic surgery patients showed a significant reduction in postoperative deep venous thrombosis.


Gynecology_Novak

Gynecology_Novak. Although low-dose heparin is considered to have no measurable effect on coagulation, most large series noted an increase in the bleeding complication rate, especially a higher incidence of wound hematoma (130). Although relatively rare, thrombocytopenia is associated with low-dose heparin use and was found in 6% of patients after gynecologic surgery (130). If patients remain on low-dose heparin for more than 4 days, it is reasonable to check their platelet count to assess the possibility of heparin-induced thrombocytopenia.


Gynecology_Novak

Gynecology_Novak. Low-molecular-weight heparins (LMWH) are fragments of heparin that vary in size from 4,500 to 6,500 Da. When compared with unfractionated heparin, LMWH have more anti-Xa and less antithrombin activity, leading to less effect on partial thromboplastin time and possibly leading to fewer bleeding complications (131). An increased half-life of 4 hours results in increased bioavailability when compared with unfractionated heparin. The increase in half-life of LMWH allows the convenience of once-a-day dosing.


Gynecology_Novak

Gynecology_Novak. Randomized controlled trials compared LMWH with unfractionated heparin in patients undergoing gynecologic surgery. In all studies, there was a similar incidence of deep venous thrombosis (DVT). Bleeding complications were similar between the unfractionated heparin and LMWH groups (132). A meta-analysis of general surgery and gynecological surgery patients from 32 trials indicated that daily LMWH administration is as effective as unfractionated heparin in DVT prophylaxis without any difference in hemorrhagic complications (133).


Gynecology_Novak

Gynecology_Novak. Stasis in the veins of the legs occurs while the patient is undergoing surgery and continues postoperatively for varying lengths of time. Stasis occurring in the capacitance veins of the calf during surgery, plus the hypercoagulable state induced by surgery, are the prime factors contributing to the development of acute postoperative DVT. Prospective studies of the natural history of postoperative DVT showed that the calf veins are the predominant site of thrombi and that most thrombi develop within 24 hours of surgery (134). Although probably of only modest benefit, reduction of stasis by short preoperative hospital stays and early postoperative ambulation should be encouraged for all patients. Elevation of the foot of the bed, raising the calf above heart level, allows gravity to drain the calf veins and should further reduce stasis.


Gynecology_Novak

Gynecology_Novak. Graduated Compression Stockings Controlled studies of graduated compression stockings are limited but do suggest modest benefit when they are carefully fitted (135). Poorly fitted stockings may be hazardous to some patients who develop a tourniquet effect at the knee or midthigh (126). Variations in human anatomy do not allow perfect fit of all patients to available stocking sizes. The simplicity of graduated compression stockings and the absence of significant side effects are probably the two most important reasons that they are included in routine postoperative care. Compared to thigh length stockings, calf-high stockings appear to offer the same degree of venous thromboembolism protection.


Gynecology_Novak

Gynecology_Novak. Intermittent Pneumatic Compression The largest body of literature dealing with the reduction of postoperative venous stasis deals with intermittent compression of the leg by pneumatically inﬂated sleeves placed around the calf or leg during intraoperative and postoperative periods. Various pneumatic compression devices and leg sleeve designs are available, and the literature has not demonstrated superiority of one system over another. Calf compression during and after gynecologic surgery significantly reduces the incidence of DVT on a level similar to that of low-dose heparin. In addition to increasing venous ﬂow and pulsatile emptying of the calf veins, intermittent pneumatic compression appears to augment endogenous fibrinolysis, which may result in lysis of very early thrombi before they become clinically significant (136).


Gynecology_Novak

Gynecology_Novak. The duration of postoperative external pneumatic compression differed in various trials. External pneumatic compression may be effective when used in the operating room and for the first 24 hours postoperatively in patients with benign conditions who will ambulate on the first postoperative day (136,137). External pneumatic compression used in patients undergoing major surgery for gynecologic malignancy reduced the incidence of postoperative venous thromboembolic complications by nearly threefold, but only if calf compression was applied intraoperatively and for the first 5 postoperative days (138,139). Patients with gynecologic malignancies may remain at risk for a longer period than general surgical patients because of stasis and hypercoagulable Management of Postoperative Deep Venous Thrombosis and Pulmonary Embolism states; therefore, these patients appear to benefit from longer use of intermittent pneumatic compression.


Gynecology_Novak

Gynecology_Novak. Management of Postoperative Deep Venous Thrombosis and Pulmonary Embolism states; therefore, these patients appear to benefit from longer use of intermittent pneumatic compression. Intermittent pneumatic leg compression has no significant side effects or risks and is considered slightly more cost-effective when compared with pharmacologic methods of prophylaxis (140). Compliance in wearing the leg compression while in bed is of utmost importance, and the patient and nursing staff should be educated to the proper regimen for maximum benefit. The use of low-dose heparin or LMWH or intermittent pneumatic compression is a reasonable strategy in the care of women at moderate risk for postoperative venous thromboembolism. In high-risk patients, consideration should be given to using a pharmacologic method along with intermittent pneumatic compression.


Gynecology_Novak

Gynecology_Novak. Because pulmonary embolism is the leading cause of death following gynecologic surgical procedures, identification of high-risk patients and the use of prophylactic venous thromboembolism regimens are essential parts of management (125,126,141). The early recognition of DVT and pulmonary embolism and immediate treatment are critical. Most pulmonary emboli arise from the deep venous system of the leg following gynecologic surgery; the pelvic veins are a known source of fatal pulmonary emboli.


Gynecology_Novak

Gynecology_Novak. The signs and symptoms of DVT of the lower extremities include pain, edema, erythema, and prominent vascular pattern of the superficial veins. These signs and symptoms are relatively nonspecific; 50% to 80% of patients with these symptoms will not have DVT (142). Conversely, approximately 80% of patients with symptomatic pulmonary emboli have no signs or symptoms of thrombosis in the lower extremities (143). Because of the lack of specificity when signs and symptoms are recognized, additional tests should be performed to establish the diagnosis of DVT.


Gynecology_Novak

Gynecology_Novak. Doppler Ultrasound B-mode duplex Doppler imaging is the most common technique for the diagnosis of symptomatic venous thrombosis, especially when it arises in the proximal lower extremity. With duplex Doppler imaging, the femoral vein can be visualized and clots may be seen directly (144). Compression of the vein with the ultrasound probe tip allows assessment of venous collapsibility; the presence of a thrombus diminishes vein wall collapsibility. Doppler imaging is less accurate when evaluating the calf and the pelvic veins.


Gynecology_Novak

Gynecology_Novak. Venography Although venography is the standard technique for diagnosis of DVT, other diagnostic studies are accurate when performed by a skilled technologist and, in nearly all patients, may replace the need for contrast venography. Venography is moderately uncomfortable, requires the injection of a contrast material that may cause allergic reaction or renal injury, and may result in phlebitis in approximately 5% of patients (145). If the results of noninvasive imaging are normal or inconclusive and the clinician remains concerned given clinical symptoms, venography should be performed to obtain a definitive answer. Magnetic Resonance Venography In addition to having a sensitivity and specificity comparable to venography, magnetic resonance venography (MRV) may detect thrombi in pelvic veins that are not imaged by venography (146). The primary drawback to MRV is the time involved in examining the lower extremity and pelvis and the expense of this technology.


Gynecology_Novak

Gynecology_Novak. The treatment of postoperative DVT requires the immediate institution of anticoagulant therapy. Treatment may be with either unfractionated heparin or LMWH, followed by 6 months of oral anticoagulant therapy with warfarin (Coumadin). Unfractionated Heparin After venous thromboembolism is diagnosed, unfractionated heparin should be initiated to prevent proximal propagation of the thrombus and allow physiological thrombolytic pathways to dissolve the clot. An initial bolus of 80 U per kilogram is given intravenously, followed by a continuous infusion of 1,000 to 2,000 U per hour (18 U/kg/hour). Table 22.12 Heparin Administration for Treatment of Deep Venous Thrombosis or Pulmonary Embolism: Weight-Based Nomogram Time of Administration Dose Initial dose 80-U/kg bolus, then 18 U/kg/h The APTT should be measured every 6 h and the heparin dose adjusted as follows: APTT <35 seconds (<1.2 × control) 80-U/kg bolus, then 4 U/kg/h


Gynecology_Novak

Gynecology_Novak. Initial dose 80-U/kg bolus, then 18 U/kg/h The APTT should be measured every 6 h and the heparin dose adjusted as follows: APTT <35 seconds (<1.2 × control) 80-U/kg bolus, then 4 U/kg/h APTT 35–45 seconds (1.2–1.5 × control) 40-U/kg bolus, then 2 U/kg/h APTT 46–70 seconds (1.5–2.3 × control) No change APTT 71–90 seconds (2.3–3 × control) Decrease infusion rate by 2 U/kg/h APTT >90 seconds (>3 × control) Hold infusion for 1 h, then decrease infusion rate by 3 U/kg/h APTT, activated partial thromboplastin time. Reprinted from Raschke RA, Reilly BM, Guidry JR, et al. The weight-based heparin dosing nomogram compared with a “standard care” nomogram. Ann Intern Med 1993;119:874–881, with permission.


Gynecology_Novak

Gynecology_Novak. Heparin dosage is adjusted to maintain activated partial thromboplastin time (APTT) levels at a therapeutic level 1.5 to 2.5 times the control value. Initial APTT should be measured after 6 hours of heparin administration and the dose adjusted as necessary. Patients having sub-therapeutic APTT levels in the first 24 hours have a 15-fold increased risk of recurrent VTE when compared to patients who are adequately anticoagulated. Patients should be managed aggressively using intravenous heparin to achieve prompt anticoagulation. A weight-based nomogram is helpful in achieving a therapeutic APTT level (Table 22.12) (147). Oral anticoagulant (warfarin) administration may be started on the first day of heparin infusion. The international normalized ration (INR) should be monitored daily until a therapeutic level is achieved (2.0 to 3.0 times normal value). The change in the INR resulting from warfarin administration often precedes the anticoagulant effect by approximately 2 days, during


Gynecology_Novak

Gynecology_Novak. a therapeutic level is achieved (2.0 to 3.0 times normal value). The change in the INR resulting from warfarin administration often precedes the anticoagulant effect by approximately 2 days, during which time low protein C levels are associated with a transient hypercoagulable state. Therefore, heparin should be administered until the INR was maintained in a therapeutic range for at least 2 days, confirming proper warfarin dose. Intravenous heparin may be discontinued in 5 days if an adequate IRN level is established.


Gynecology_Novak

Gynecology_Novak. Low-Molecular-Weight Heparin Two LMWH preparations (enoxaparin and dalteparin) were effective in the treatment of venous thromboembolism and have a cost-effective advantage over intravenous heparin in that they may be administered in the outpatient setting.


Gynecology_Novak

Gynecology_Novak. The dosages used in treatment of thromboembolism are unique and weight adjusted according to each LMWH preparation. Because LMWH has a minimal effect on APPT, serial laboratory monitoring of these levels is not necessary. Similarly, monitoring of anti-Xa activity (except in difficult cases or those with renal impairment) is not of significant benefit in a dose adjustment of LMWH. The increased bioavailability associated with LMWH allows for twice-a-day dosing, potentially making outpatient management an option for a subset of patients. A meta-analysis involving more than 4,000 patients from 22 trials suggests that LMWH is more effective, safer, and less costly when compared with unfractionated heparin in preventing recurrent thromboembolism (148).


Gynecology_Novak

Gynecology_Novak. Many of the signs and symptoms of pulmonary embolism are associated with other, more commonly occurring pulmonary complications following surgery. The classic findings of pleuritic chest pain, hemoptysis, shortness of breath, tachycardia, and tachypnea should alert the physician to the possibility of a pulmonary embolism. Many times the signs are subtle and may be demonstrated only by a persistent tachycardia or a slight elevation in the respiratory rate. Patients suspected of pulmonary embolism should be evaluated initially by chest x-ray, electrocardiography, and arterial blood gas assessment. Any evidence of abnormality should be further evaluated by a spiral CT scan of the chest or a ventilation-perfusion lung scan. A high percentage of lung scans may be interpreted as “indeterminate.” In this setting, careful clinical evaluation and judgment are required to decide whether pulmonary arteriography should be performed to document or exclude the presence of a pulmonary embolism.


Gynecology_Novak

Gynecology_Novak. The treatment of pulmonary embolism is as follows: 1. Immediate anticoagulant therapy, identical to that outlined for the treatment of DVT, should be initiated. 2. Respiratory support, including oxygen and bronchodilators and an intensive care setting, if necessary. 3. Although massive pulmonary emboli are usually quickly fatal, rarely pulmonary embolectomy is successful. 4. Pulmonary artery catheterization with the administration of thrombolytic agents bears further evaluation and may be important in patients with massive pulmonary embolism. 5.


Gynecology_Novak

Gynecology_Novak. 4. Pulmonary artery catheterization with the administration of thrombolytic agents bears further evaluation and may be important in patients with massive pulmonary embolism. 5. Vena cava interruption may be necessary in situations in which anticoagulant therapy is ineffective in the prevention of rethrombosis and repeated embolization from the lower extremities or pelvis. A vena cava filter may be inserted percutaneously above the level of the thrombosis and caudad to the renal veins. In most cases, anticoagulant therapy is sufficient to prevent repeat thrombosis and embolism and to allow the patient’s own endogenous thrombolytic mechanisms to lyse the pulmonary embolus. Management of Medical Problems


Gynecology_Novak

Gynecology_Novak. Management of Medical Problems Endocrine Disease The three most frequent endocrine disorders that occur in patients undergoing gynecologic surgery are diabetes mellitus, thyroid disease, and adrenal abnormalities. The pathophysiology of these disorders aids in understanding the effects of surgery on patients with these problems.


Gynecology_Novak

Gynecology_Novak. Diabetes Mellitus According to the American Diabetes Association, 9.3 million American women, or 10.2% of all women older than 20 years, suffer from diabetes (149). Approximately 50% of individuals with diabetes mellitus (DM) will require surgery during their lives (150). Many of these procedures are a direct result of the complications of DM: retinopathy, nephropathy, large-and small-vessel occlusive disease, and coronary artery disease. It is the direct effect of DM on the end organs that determines the risk of surgery, rather than the type or duration of surgery, or the management of the condition itself. Diabetes mellitus is a complicated medical disorder of glucose metabolism that is related to a lack of production of, or resistance to, insulin.


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Gynecology_Novak. Patients with DM experience exaggerated hyperglycemia during surgery. This hyperglycemia is multifactorial in origin and is secondary to increased catecholamine production, which inhibits pancreatic release of insulin and causes increased insulin resistance at the end organs. Elevations in instrumental hormones, such as cortisol, growth hormone, and glucagon, enhance gluconeogenesis and glycogenolysis (151). Goals of the preoperative assessment and perioperative management are to ensure metabolic homeostasis and to anticipate problems arising from preexisting complications. Preoperative risk assessment for diabetes should begin with a review of systems. Nocturia, polyuria, polydipsia, glucosuria, obesity, previous gestational diabetes, ethnicity, and family history are relevant aspects of the history. The current criteria for diagnosis of diabetes include (152): 1. Polyuria, polydipsia, or unexplained weight loss with a random nonfasting glucose of ≥200 mg/dL, or 2.


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Gynecology_Novak. Polyuria, polydipsia, or unexplained weight loss with a random nonfasting glucose of ≥200 mg/dL, or 2. Fasting glucose ≥126 mg/dL (in which fasting is defined as no food intake for 8 hours), 3. Two-hour oral glucose tolerance test of 75 g, with serum glucose ≥200 mg/dL, or 4. Hemoglobin A1c ≥6.5%. Confirmation of the diagnosis requires repeating the same test on a different day or concordant results of two different tests simultaneously. Preoperative risk assessment in the previously diagnosed individual with diabetes should begin with the knowledge of the type of diabetes. Type 1 (insulin dependent) diabetes, or type 2 diabetes (noninsulin dependent), should be established because the perioperative management of each differs. The patient’s routine glucose management strategies, glucose levels, medications, and baseline hemoglobin A1c should be assessed (153). The presence of end-organ complications of diabetes should be documented.


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Gynecology_Novak. Large-and small-vessel arterial occlusive disease is the single most important risk factor in the preoperative setting. A careful history and physical examination should be performed to determine the presence or absence of coronary artery or cerebral vascular disease (150). When extended surgery is possible, as with surgery for gynecologic cancer, exercise stress testing or dipyridamole-thallium imaging should be considered to rule out occult coronary artery disease. Perioperative beta-blockade should be continued for patients already on beta-blockers at baseline. For patients with inducible ischemia, coronary artery disease, or multiple clinical risk factors for heart disease, perioperative beta-blockade should be considered, with initiation and careful titration of medication several weeks prior to surgery (154,155). Assessment of end-organ disease in the retina, kidney, and carotid arteries or evidence of peripheral vascular disease by the presence of foot ulcers should alert the


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Gynecology_Novak. prior to surgery (154,155). Assessment of end-organ disease in the retina, kidney, and carotid arteries or evidence of peripheral vascular disease by the presence of foot ulcers should alert the clinician to the presence of small-or large-vessel disease. Diabetic nephropathy should be documented carefully preoperatively. Imaging studies using contrast dye should be avoided, and alternative testing should be performed to reduce the incidence of acute tubular necrosis. If a contrast study must be performed, adequate hydration both before and after the procedure is essential, and oral metformin should be withheld for 24 to 48 hours after the procedure.


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Gynecology_Novak. Diabetes is associated with increased perioperative infections (156). Preoperative evaluation should include examination of the skin and urine sediment to detect asymptomatic infection. Wound infections, skin infections, pneumonia, and urinary tract infections account for two-thirds of the postoperative complications in patients with diabetes (151). There is a known predisposition for patients with DM to have increased colonization by methicillin-resistant Staphylococcus aureus, increased infections by gram-negative and staphylococcal bacteria, and an increased incidence of gram-negative and group B streptococcal sepsis (157–159). Seven percent of individuals with diabetes will have postoperative gram-negative sepsis, a rate approximately seven times higher than that of the nondiabetic population. These complications occur more often in patients with poor glucose control, probably caused by impaired leukocyte function in the presence of hyperglycemia (160,161). Individuals with DM


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Gynecology_Novak. population. These complications occur more often in patients with poor glucose control, probably caused by impaired leukocyte function in the presence of hyperglycemia (160,161). Individuals with DM have an increased risk of wound dehiscence and wound infection, possibly related to an impaired immune function, with changes in phagocytosis, cell-mediated immunity, and intracellular bactericidal activity (162). Autonomic neuropathy was documented in patients with DM, and these autonomic impairments can lead to intraoperative hypotension, cardiac arrhythmias, sudden death and abnormal motility of the esophagus, stomach, and small intestine (151). Peripheral sensory and motor neuropathies may or may not be present. The presence of any manifestations of autonomic neuropathy intra-operatively should prompt close monitoring of the affected organ system in the postoperative period.


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Gynecology_Novak. The traditional goal for glucose control perioperatively is to maintain the glucose level below 200 mg/dL (151,153). Significant debate continues regarding whether strict glycemic control below 110 mg/dL may be beneficial in critically ill patients (163,164). Perioperative hyperglycemia (>250 mg/dL) is associated with increased susceptibility to infection and poor wound healing. Extreme hyperglycemia predisposes type 1 DM patients to metabolic acidosis, and surgery should be canceled until normal acid-base balance is documented. Hyperosmolar hyperglycemic nonketotic states must be recognized before surgery. Electrolyte disturbances, especially those related to sodium and potassium, should be corrected preoperatively. Hypoglycemia should be avoided during the perioperative period.


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Gynecology_Novak. The history and type of DM are important factors to consider when devising a perioperative management plan. Patients with noninsulin-dependent diabetes (type 2) whose condition is controlled with oral hypoglycemic agents or diet are best treated with intravenous ﬂuids containing no dextrose and should not be given insulin intraoperatively. Oral administration of hypoglycemic agents should be discontinued when the patient ceases oral intake of food, and hyperglycemic episodes in the perioperative period are treated with sliding-scale regular insulin if blood sugar levels exceed 200 mg/dL (151,153).


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Gynecology_Novak. Insulin-dependent or type 1 diabetes poses a more difficult problem. These patients are insulin deficient and therefore require a basal rate of insulin at all times. Likewise, they require a baseline intake of glucose. They risk developing diabetic ketoacidosis whether or not they are eating (153). Preoperatively, the goals include avoiding ketoacidosis and hypoglycemia, and, to a lesser extent, hyperglycemia. Traditionally, approximately one-third to one-half of the patient’s usual daily dose of NPH insulin (intermediate acting) is given subcutaneously the morning of surgery. Omit any short-acting insulin without oral intake. An infusion of 5% dextrose should be given while being restricted from oral intake. Additional regular insulin can be administered in the operating room as needed (150,153). If patients are normally on a continuous insulin infusion, they may continue at their usual infusion rate. There is no single regimen that is superior for the intraoperative management of


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Gynecology_Novak. (150,153). If patients are normally on a continuous insulin infusion, they may continue at their usual infusion rate. There is no single regimen that is superior for the intraoperative management of type 1 diabetic patients. A continuous intravenous insulin infusion is indicated for patients with unstable type 1 diabetes, those who require emergency surgery while in ketoacidosis, and those undergoing long, complex procedures (161). Consultation with endocrine and anesthesia colleagues can be helpful in managing these complex regimens.


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Gynecology_Novak. Postoperative Management Postoperative monitoring of patients with DM includes careful monitoring of serum glucose levels. If an intravenous insulin regimen is used, blood glucose levels must be checked every 1 to 2 hours. If a sliding-scale insulin administration is used, blood glucose should be checked and documented approximately every 6 hours until the patient is eating and stable on her preoperative regimen. The serum glucose level should be maintained at less than 250 mg/dL, and ideally below 140 mg/dL when fasting and below 180 mg/dL with random draws (165,166). For type 2 diabetics, oral hypoglycemics can be restarted when the patient resumes eating, except with metformin, which requires normal renal and liver function (153).


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Gynecology_Novak. It is essential to prevent the development of severe hypoglycemia or hyperglycemia and the associated complications of diabetic ketoacidosis or a hyperosmolar state. Rigorous perioperative management may obviate some of the infectious and wound-healing complications that are more common in these patients (167). Thyroid Syndromes Thyroid dysfunction should be suspected in any patient with a history of hyperthyroidism, use of thyroid replacement medication or antithyroid medication, prior thyroid surgery, or radioactive iodine therapy.


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Gynecology_Novak. Diffuse toxic goiter (Grave’s disease) is the most common cause of hyperthyroidism and results from abnormal stimulation of the thyroid gland by antithyroid antibodies. Other causes of hyperthyroidism include multinodular goiter, excess thyroid hormone, or thyroiditis. Any signs or symptoms suggestive of weight loss, tachycardia, atrial fibrillation, goiter, or proptosis should initiate a more extensive laboratory evaluation of thyroid function. Total thyroxin, free triiodothyronine (T3), free thyroxin (T4), and thyroid-stimulating hormone (TSH) tests are useful in diagnosis. In hyperthyroidism, the free T4 level will be elevated, and the TSH level will be suppressed (154). A new diagnosis of hyperthyroidism necessitates postponement of elective surgery until adequate treatment with antithyroid medication is received because of the risk of thyroid storm. Thyroid storm is associated with mortality of up to 40% (168). Stable thyroid conditions do not require any special preoperative


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Gynecology_Novak. medication is received because of the risk of thyroid storm. Thyroid storm is associated with mortality of up to 40% (168). Stable thyroid conditions do not require any special preoperative treatments or tests. Ideally, an euthyroid state should be maintained for 3 months before elective surgery. In emergent situations, beta-blockers can be used to counter sympathomimetic drive such as palpitations, diaphoresis, and anxiety. Antithyroid medications such as propylthiouracil (PTU)or radioactive iodine do not render patients euthyroid quickly enough for urgent surgery. Radioactive iodine requires 6 to 18 weeks to establish a euthyroid state (154). When thyroid dysfunction is corrected and maintained for several months, elective surgery can proceed without additional perioperative monitoring. Antithyroid medications should be resumed with return of bowel function. If a prolonged delay in resumption of oral intake is encountered, PTU and methimazole can be administered rectally (169). When


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Gynecology_Novak. Antithyroid medications should be resumed with return of bowel function. If a prolonged delay in resumption of oral intake is encountered, PTU and methimazole can be administered rectally (169). When time does not permit establishment of a euthyroid state preoperatively, oral administration of PTU and a beta-blocker can be implemented for 2 weeks before surgery, and with careful monitoring, optimal results can be achieved (170). Alternatively, oral beta-blockers, glucocorticoids, and sodium iopanoate can be used for 5 days, followed by surgery on day 6 (169). In the emergent setting, close monitoring of the patient for tachycardia, arrhythmias, and hypertension is necessary. Beta-blockers can control these symptoms until definitive therapy can be initiated after recovery from surgery.


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Gynecology_Novak. Any signs suggestive of the development of thyroid storm—including hemodynamic instability, tachycardia, arrhythmias, hyperreﬂexia, diarrhea, fever, delirium, or congestive heart failure— mandate transfer to an intensive care setting for optimal monitoring and management in consultation with a medical endocrinologist. Such thyroid instability can be triggered by underlying infection, which requires diagnosis and treatment to facilitate management of this medical emergency. The mortality rate from thyroid storm is reportedly between 10% and 75% (169). Treatment of thyroid storm consists of beta-blockers, thioamides, iodine, iodinated contrast agents, and corticosteroids (151). Aspirin should not be given for fever in the patient with thyroid storm because it may interfere with the protein binding of T4 and T3, resulting in increased free serum concentrations (151).


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Gynecology_Novak. The incidence of hypothyroidism is approximately 1% in the adult population, and 5% in adults older than 50 years (154). In women older than 60 years, the incidence of hypothyroidism may approach 6% (168). Hypothyroidism is 10 times more common in women than in men (154). Many such cases are secondary to previous antithyroid therapy (radioactive iodine or thyroidectomy) for hyperthyroidism. The most common primary cause of hypothyroidism is Hashimoto’s thyroiditis, an autoimmune condition (154). A history of lethargy, cold intolerance, lassitude, weight gain, ﬂuid retention, constipation, dry skin, hoarseness, periorbital edema, and brittle hair can be indicative of inadequate thyroid function. In this setting, physical findings of increased relaxation phase of deep tendon reﬂexes, cardiomegaly, pleural or pericardial effusions, or peripheral edema should stimulate further investigation of thyroid function by assessment of TSH and free T4 levels. Hypothyroidism decreases cardiac


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Gynecology_Novak. pleural or pericardial effusions, or peripheral edema should stimulate further investigation of thyroid function by assessment of TSH and free T4 levels. Hypothyroidism decreases cardiac output by 30% to 50% as a result of decreased stroke volume and heart rate (171). Hyponatremia may be associated with hypothyroidism because of the inability of the kidneys to excrete water (171). When elective surgery is planned for severely hypothyroid patients, surgery should be postponed until thyroid replacement therapy is initiated (154). In patients with mild or moderate hypothyroidism, the delay of surgery is controversial (154).


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Gynecology_Novak. For young patients with mild to moderate hypothyroidism, a starting dose of 1.6 μg/kg of thyroid hormone replacement can be given. In elderly patients, thyroxin dosage (0.025 mg once a day) should be given with interval dose increases every 4 to 6 weeks until the patient is euthyroid (168). Dosage levels can ultimately be titrated against TSH levels. In severely hypothyroid patients requiring urgent or emergent surgery, intravenous T3 or T4 may be given, along with intravenous corticosteroids to avoid consequences of unrecognized adrenal insufficiency (151,154). In the immediate postoperative setting, T4 therapy can be held for 5 to 7 days while waiting for return of bowel function because the half-life of circulating T4 is approximately 5 to 9 days (170). If more than 5 to 7 days of decreased bowel function are expected, T4 can be given by the intramuscular or intravenous route at approximately 80% of the oral dose (171,172).


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Gynecology_Novak. Adrenal Insufficiency Adrenal insufficiency may result in catastrophic postoperative complications, including death. The most common cause of adrenal insufficiency in the surgical patient is secondary to the exogenous use of corticosteroids. The physician should ascertain whether a patient used exogenous steroids for asthma (including inhaled steroids), malignant conditions, arthritis, or irritable bowel syndrome. The type of steroid use, the route, the dose, the duration, and the temporal relationship to the timing of the surgical procedure must be determined. The type of surgical procedure and its associated stress should be taken into consideration. The use of high doses of exogenous steroids for prolonged periods can cause circulatory collapse, and they have adverse effects on wound healing and immunocompetence.


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Gynecology_Novak. The daily replacement dose of cortisol is approximately 5 to 7.5 mg of prednisone. Suppression of the hypothalamic–pituitary–adrenal (HPA) axis by exogenous steroids for more than a few weeks may produce relative adrenal insufficiency. When systemic steroids are used for longer periods, adrenal insufficiency may persist for up to 1 year. Short courses of low-dose oral steroids (<5mgof prednisone in a single morning dose for any duration of time, alternate-day dosing of short-acting glucocorticoids, and any dose of corticosteroids given for less than 3 weeks) are not thought to cause clinically significant suppression of the HPA axis (151,172). Use of inhaled corticosteroids of over 0.8 mg per day or class I topical glucocorticoids of 2 g per day or more may cause suppression (172). Table 22.13 Guidelines for Adrenal Supplementation Therapya


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Gynecology_Novak. Table 22.13 Guidelines for Adrenal Supplementation Therapya IV, intravenously. aPatients receiving 5 mg/d or less of prednisone should receive their normal daily replacement but do not require supplementation. Patients who receive greater than 5 mg/d of prednisone should receive the above therapy in addition to their maintenance therapy. Reprinted from Coursin DB, Wood KE. Corticosteroid supplementation for adrenal insufficiency. JAMA 2002;287:236–240, with permission.


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Gynecology_Novak. If either the dose or duration of glucocorticoid administration exceeds the preceding regimen, biochemical tests are recommended to preoperatively evaluate the function of the adrenal gland. The easiest and safest test to assess HPA function is the cosyntropin stimulation test. Cosyntropin, a synthetic analogue of adrenocorticotropic hormone, is given in a dose of 250 μg intravenously, and a blood sample is collected 30 minutes after the injection and assayed for plasma cortisol. A plasma cortisol value of greater than 18 to 20 μg/dL indicates adequate adrenal function (151,154). If the history regarding exogenous steroid use is unclear, the cosyntropin stimulation test should be considered as a preoperative test to determine whether the patient will need perioperative glucocorticoid coverage. The amount of glucocorticoid replacement should be equivalent to the normal physiologic response to surgical stress (Table 22.13) (173).