10.14639/0392-100X-N1803
Objective. We aimed to prospectively assess the effect of comorbidities on the occurrence of postoperative respiratory complications (PoRCs) after adenotonsillectomy in children with obstructive sleep apnoea syndrome (OSA) and whether otherwise healthy children need a higher level of postoperative monitoring. Methods. 577 children who had OSA and underwent adenotonsillectomy were enrolled. The effects of demographics, comorbidities and OSA on PoRCs were investigated with logistic regression analysis. Results. The PoRC rate was 4.3%. Postoperative oxygen desaturations were more marked in patients with comorbidities (p = 0.005). The presence of comorbidity increased the risk of PoRCs (odds ratio 4.234/3.226-5.241, 95% confidence intervals, p &lt; 0.001). There was no difference in apnoea-hypopnoea index (AHI) values between comorbid patients with and without PoRCs [8.2 (3.8-50.2) vs 14.3 (11.7-23.3)]. (p = 0.37). In the group of patients without comorbidities, PoRCs were associated with a higher AHI [14.7 (3.4-51.3) vs 3.9 (2.0- 8.0), p &lt; 0.001]. Conclusions. Comorbidities are more closely linked with PoRCs than OSA severity. In patients without comorbidity, PoRCs are associated with OSA severity and usually occur within the first 2 hours after the intervention.
text/xml
1827-675X
1803
en
Zsófia Lázár
http://creativecommons.org/licenses/by-nc-nd/4.0
ACTA Otorhinolaryngologica Italica
respiratory complications
Postoperative respiratory complications in children with obstructive sleep apnoea syndrome
Text.Serial.Journal
https://www.actaitalica.it/
42
OSAHS
2022-05-16
2021-08-29
2022-05-23
2022-05-23
162-168
1
Zsófia Lázár
2022/05/16
10.14639/0392-100X-N1803
162
Department of Pulmonology, Semmelweis University, Budapest, Hungary
1827-675X
respiratory complications
en
168
Postoperative respiratory complications in children with obstructive sleep apnoea syndrome
https://www.actaitalica.it/article/download/1803/796
42
ACTA OTORHINOLARYNGOLOGICA ITALICA 2022;42:162-168; doi: 10.14639/0392-100X-N1803




OSAHS


Postoperative respiratory complications in children
with obstructive sleep apnoea syndrome
Complicanze respiratorie postoperatorie nei pazienti pediatrici affetti da sindrome
delle apnee ostruttive notturne
Pálma Benedek1,3, Fanni Keserü1,3, Gabriella Kiss2, Zsolt Bella3, László Rovó3, Gábor Katona1,
András Bikov4, Balázs Csoma5, Zsófia Lázár5
1
 Department of Otolaryngology, Heim Pál National Institute of Paediatrics, Budapest, Hungary; 2 Department of Anaesthesiology and
Intensive Care, Heim Pál National Institute of Paediatrics, Budapest, Hungary; 3 Department of Oto-Rhino-Laryngology and Head-
Neck Surgery, University of Szeged, Szeged, Hungary; 4 Wythenshawe Hospital, Manchester University NHS Foundation Trust,
Manchester, United Kingdom; 5 Department of Pulmonology, Semmelweis University, Budapest, Hungary


SUMMARY
Objective. We aimed to prospectively assess the effect of comorbidities on the occurrence
of postoperative respiratory complications (PoRCs) after adenotonsillectomy in children
with obstructive sleep apnoea syndrome (OSA) and whether otherwise healthy children
need a higher level of postoperative monitoring.
Methods. 577 children who had OSA and underwent adenotonsillectomy were enrolled.
The effects of demographics, comorbidities and OSA on PoRCs were investigated with
logistic regression analysis.
Results. The PoRC rate was 4.3%. Postoperative oxygen desaturations were more marked in pa-
tients with comorbidities (p = 0.005). The presence of comorbidity increased the risk of PoRCs
(odds ratio 4.234/3.226-5.241, 95% confidence intervals, p < 0.001). There was no difference
in apnoea-hypopnoea index (AHI) values between comorbid patients with and without PoRCs
[8.2 (3.8-50.2) vs 14.3 (11.7-23.3)]. (p = 0.37). In the group of patients without comorbidities,
PoRCs were associated with a higher AHI [14.7 (3.4-51.3) vs 3.9 (2.0- 8.0), p < 0.001].
Conclusions. Comorbidities are more closely linked with PoRCs than OSA severity. In                   Received: August 29, 2021
                                                                                                      Accepted: November 29, 2021
patients without comorbidity, PoRCs are associated with OSA severity and usually occur
within the first 2 hours after the intervention.
                                                                                                      Correspondence
KEY WORDS: sleep breathing disorders, obstructive sleep apnoea, apnoea-hypopnoea                      Pálma Benedek
index, postoperative monitoring, comorbidity, respiratory complications                               Department of Otolaryngology, Heim Pál National
                                                                                                      Institute of Paediatrics, Budapest, Hungary, Üllői
                                                                                                      Street 86, Budapest, H-1089, Hungary.
RIASSUNTO                                                                                             Tel. +36 309150865
Obiettivo. Abbiamo valutato prospetticamente l’effetto delle comorbilità sull’insorgenza di           E-mail: dr.benedek.palma@gmail.com
complicanze respiratorie postoperatorie (PoRC) dopo adenotonsillectomia in bambini con
sindrome delle apnee ostruttive del sonno (OSA) e se tali bambini altrimenti sani necessi-              How to cite this article: Benedek P, Kes-
tano di un livello più elevato di monitoraggio postoperatorio.                                          erü F, Kiss G, et al. Postoperative respira-
Metodi. Sono stati arruolati 577 bambini con OSA e sottoposti ad adenotonsillectomia. Gli               tory complications in children with obstructive
effetti dei dati demografici, delle comorbilità e dell’OSA sui PoRC sono stati studiati con             sleep apnoea syndrome. Acta Otorhinolaryn-
l’analisi di regressione logistica.                                                                     gol    Ital    2022;42:162-168.     https://doi.
Risultati. Il tasso di PoRC è stato del 4,3%. Le desaturazioni di ossigeno postoperatorie erano più     org/10.14639/0392-100X-N1803
marcate nei pazienti con comorbilità (p = 0,005). La presenza di comorbilità ha aumentato il ri-
schio di PoRC (odds ratio 4,234 /3,226-5,241, intervalli di confidenza 95%/, p < 0,001). Non c’era    © Società Italiana di Otorinolaringoiatria
                                                                                                      e Chirurgia Cervico-Facciale
differenza nei valori dell’indice di apnea-ipopnea (AHI) tra i pazienti con comorbilità con e senza
PoRC (8,2 (3,8-50,2) vs 14,3 (11,7-23,3) (p = 0,37), ma nel gruppo di pazienti senza comorbilità.
                                                                                                                     OPEN ACCESS
I PoRC erano associati a un AHI più elevato (14,7 (3,4-51,3) rispetto a 3,9 (2,0-8,0), p < 0,001).
Conclusioni. Le comorbilità sono più strettamente legate ai PoRC rispetto alla gravità                This is an open access article distributed in accordance with
                                                                                                      the CC-BY-NC-ND (Creative Commons Attribution-Non-
dell’OSA. Nei pazienti senza comorbidità le PoRC sono associati alla gravità dell’OSA e di            Commercial-NoDerivatives 4.0 International) license. The
solito si verificano entro le prime 2 ore dopo l’intervento.                                          article can be used by giving appropriate credit and mentio-
                                                                                                      ning the license, but only for non-commercial purposes and
PAROLE CHIAVE: disturbi respiratori del sonno, apnea ostruttiva del sonno, indice                     only in the original version. For further information: https://
apnea-ipopnea, monitoraggio postoperatorio, comorbilità, complicanze respiratorie                     creativecommons.org/licenses/by-nc-nd/4.0/deed.en




162
                                                                      Postoperative complications in children with obstructive sleep apnoea




Introduction                                                     be performed in young children (< 2 years old) and in pa-
                                                                 tients with Down syndrome or craniofacial malformation if
Sleep disordered breathing (SDB) is a continuum from ha-
                                                                 they present with moderate-to-severe OSA. However, there
bitual snoring through upper airway resistance syndrome          was no agreement on the location (paediatric intensive care
to obstructive sleep apnoea (OSA). OSA is the most severe        unit, postoperative anaesthesia unit, or ward with oximetry)
form of SDB, characterised by repetitive, partial, or com-       or the duration (overnight or a shorter period) of postopera-
plete upper airway obstruction during sleep that disturbs        tive monitoring. Identifying factors leading to PoRCs are
normal breathing and fragments the sleep pattern 1. The          therefore of essential clinical value as they can guide deci-
prevalence of OSA is 1-3% among children, and 3-12% of           sions regarding postoperative management.
the paediatric population suffers from snoring 2. Aetiology,     The aim of this study was to assess the effect of the co-
symptoms, diagnostic methods, and treatment in paediatric        morbidities and the severity of OSA on the occurrence of
OSA are different from those in adults 1, although sleep         PoRCs after adenotonsillectomy in patients with OSA and
fragmentation and gas exchange abnormality can lead to           to determine the duration and level of postoperative care in
severe cardiovascular, neurological, olfactory, and behav-       otherwise healthy children.
ioural disorders in the paediatric population as well 3. Chil-
dren with OSA are more likely to exhibit behavioural and
integration problems, hyperactivity, and learning difficul-      Materials and methods
ties depending on the severity and duration of the disease 4.    Subjects
The main predisposing factor for OSA in childhood is ad-         We prospectively collected data between 1 January 2015
enotonsillar hypertrophy 2, but there are other risk factors     and 31 December 2018 from 577 children who underwent
including obesity, craniofacial malformations, the presence      polysomnography (PSG) followed by adenoid and/or tonsil
of glycogen storage disorders, sickle cell anaemia, achon-       surgery at Heim Pal National Paediatric Institute, Buda-
droplasia, prematurity and neuromuscular disorders 1.            pest, Hungary due to symptoms of sleep-related breathing
Regarding treatment, the most common ear-nose-throat             disorders. The indications for surgery were clinical symp-
(ENT) surgical procedure in children is adenoid and/or           toms of OSA and abnormal PSG findings 13. According to
tonsil surgery 1. One of the most common and important           the caregivers’ reports, all subjects presented snoring and
complications is bleeding 5, but respiratory complications       had other concomitant symptoms including apnoeas, para-
are equally significant occurring up to several hours post-      doxical breathing, abnormal body position during sleep,
operatively. These complications include exacerbation of         frequent awakenings, enuresis, or daytime symptoms (be-
apnoea, desaturation, laryngospasm, bronchospasm, pul-           havioural problems, attention deficit hyperactivity disorder
monary oedema and atelectasia, pneumothorax, pneumo-             and daytime sleepiness). Details from past medical history,
mediastinum and pleural exudates 6,7. Postoperative respir-      physical status, results of PSG, treatment and postopera-
atory complications (PoRC) after adenotonsillectomy were         tive complications were recorded. Obesity was defined as a
recorded 10 times more frequently among patients with            body mass index (BMI) at or above the 95th percentile for
OSA than in those without by Jaryszak et al. 8. They found       children of the same age and gender. Children born before
correlation between PoRC and higher AHI, hypopnoea in-           37 completed weeks of gestation were considered prema-
dex, BMI and lower nadir oxygen saturation. In addition,         ture. Patients with laryngeal abnormalities diagnosed with
craniofacial and neuromuscular comorbidities, upper air-         fibreoptic laryngoscopy were excluded.
way inflammation (allergic or vasomotor rhinitis) and obe-
sity accompanying OSA further and markedly elevate the           Polysomnography
risk for PoRCs 9,10.                                             Polysomnography was performed with a Somnomedics
The European Respiratory Society (ERS) states that the risk      Somnoscreen plus device (Somnomedics, Randersacker,
factors for PoRCs include age under 3 years, an apnoea-hy-       Germany) according to guidelines 13. Polysomnographic
popnoea index (the number of the apnoeas and hypopnoeas          readings were evaluated by a physician (PB) experienced in
per hour) more than 26/h, an oximetry recording with three       sleep medicine. Electroencephalogram (EEG), electroocu-
or more clusters of desaturation (4%) and at least three de-     logram (EOG) and electromyogram (EMG), thoracic and
saturations to < 90%, obesity or low weight and neuromus-        abdominal respiratory excursions, breath sounds, nasal pres-
cular, craniofacial or genetic disorders 11. The International   sure, electrocardiogram (ECG) and oxygen saturation were
Otolaryngology Group has recently published a consensus          recorded. Sleep stages, movements and cardiopulmonary
document on the diagnosis and management of paediatric           events were scored manually according to the guideline de-
OSA 12. It declares that postoperative monitoring should         veloped by the American Academy of Sleep Medicine and



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P. Benedek et al.




updated in 2012 13. Hypnogram, number of microarousals,                       shown as mean ± standard deviation or median (interquar-
apnoea-hypopnoea index (AHI; the number of apnoeas and                        tile range). Groups were compared with t-test, analysis of
hypopnoeas per sleeping hour), EEG-confirmed respiratory                      variance (ANOVA), Mann-Whitney and Kruskal-Wallis
disturbance index and oxygen desaturation index (DI) were                     tests. Categorical data were analysed with chi-square or
evaluated. Desaturation index (DI) indicates the number of                    Fisher’s exact tests (GraphPad Prism 7.0, GraphPad Soft-
periods with desaturation (min. 3% fall in oxygen satura-                     ware, San Diego, USA). The association between clinical
tion) per hour. Obstructive apnoea was defined if there was                   variables and demographics as well as PoRCs was evalu-
a drop in the peak signal excursion of the oronasal thermal                   ated with multivariate logistic regression. This was inves-
sensor by ≥ 90% of pre-event baseline that lasted for at least                tigated separately in patients with and without comorbidi-
2 breaths and associated with the presence of respiratory                     ties. We calculated the required sample size for Fisher exact
effort 13. Criterion for hypopnoea was a drop from peak                       test of independence using the G*Power software version 3
signal excursions ≥ 30% of pre-events baseline lasting for                    (Heinrich Heine University Dusseldorf, Dusseldorf, Ger-
at least 2 breaths with ≥ 3% desaturation from pre-event                      many) 17. We used the results of a previous study that pro-
baseline or associated with an arousal 13. We analysed our                    spectively evaluated the incidence of postoperative airway-
data based on that system developed by Marcus et al. 14.                      related complications between children with and without
The severity of OSA was defined by the AHI as mild (1.0-                      comorbidities 18 as input. We expected a difference between
5.0/h), moderate (5.1-10.0/h), or severe (> 10.0/h). Clinical                 the sample sizes of the two groups, so we utilised the find-
data were analysed with regards to PSG parameters includ-                     ings of another study 19, in which the incidence of crani-
ing AHI and DI.                                                               ofacial abnormalities was investigated in children with
                                                                              obstructive sleep apnoea. The calculated minimum total
Medical examination and interventions                                         sample size for the study was 131 (1-β = 0.80, α = 0.05;
The ENT examination included examination of the nose                          group with comorbidities N = 21, group without comor-
(ala nasi, septum nasi, inferior turbinates), nasopharynx,                    bidities N = 110). However, due to the lower prevalence of
and oropharynx with the size of the tonsils, which was                        comorbid conditions than expected initially, we continued
categorised by the Brodsky scale 15. Flexible fibreop-                        to recruit children to reach the minimal sample size in the
tic laryngoscopy with ER-270 FP video endoscope (FU-                          comorbid group.
JINON, Willich, Germany) was performed to evaluate the
hypopharynx and larynx to rule out laryngomalacia and
other laryngeal abnormalities. During the anaesthesiologic                    Results
examination, the anaesthetist defined the need for premedi-                   Subjects
cation, postoperative observation and treatment required.                     We recruited 577 patients for the study (Tab. II), 357 boys
Tonsil surgery is not a day-care procedure in Hungary, and                    and 220 girls from the age of 8 months to 18 years. Twenty-
patients stayed at the hospital overnight after the operation.                four children (4.2%) presented with comorbidities includ-
A monitoring system, which we previously described 16                         ing obesity (13 patients, 4 of whom suffered from Prader
was used to define the duration of postoperative monitor-                     Willi syndrome), prematurity with bronchopulmonary dys-
ing (Tab. I). Briefly, if the OSA was mild at 4 hours, and if                 plasia (3 patients), hypotonic neuromuscular disorder (3 pa-
it was moderate at 24 hours postoperative care with pulse                     tients), Down syndrome (3 patients), Pfeiffer syndrome
oximetry was used. In severe cases (AHI > 10 events/h),                       (1 patient) and Fragile X syndrome (1 patient) There were
patients were transferred to the ICU for 24 hours after the                   no differences in age and gender between patients with and
procedure. Figure 1 shows the selection process of patients                   without comorbidities; however, patients with comorbidi-
during the recruitment period.                                                ties suffered from more severe OSA (p < 0.001, Tab. II).

Statistical analysis                                                          Effect of comorbidities on postoperative respiratory com-
Data normality was tested (D’Agostino test) and data are                      plications
                                                                              The overall postoperative respiratory complication rate in
                                                                              our cohort was 4.3% (25/577). The incidence rate of com-
Table I. Postoperative monitoring protocol for patients with OSA.
                                                                              plications was significantly higher in patients with comor-
 OSA stage         AHI value               Mode of monitoring
                                                                              bidities (58.3%, 14/24 vs 2%, 11/553; p < 0.001). The pres-
 Mild OSA            1.0-5.0      4 hours pulse oximetry in a general ward
                                                                              ence of comorbidity increased the risk for PoRCs with an
 Moderate OSA        5.1-10      24 hours pulse oximetry in a general ward    odds ratio (OR) of 4. (95% confidence interval 3.6-5.2).
 Severe OSA           > 10       24 hours monitoring in intensive care unit   Complications in the group without comorbidities were



164
                                                                                                  Postoperative complications in children with obstructive sleep apnoea




Figure 1. Selection process of patients during the recruitment period. PSG: polysomnography; PoRCs: postoperative respiratory complications.


desaturations (all 11 cases) necessitating supplemental                                   out a comorbidity (72% ± 12% vs 83% ± 12%, p = 0.005)
oxygen therapy, apnoeas in 6 cases, and one patient was                                   (Fig. 2). Specifically, apnoea worsened in 6 cases, while
diagnosed with bronchopneumonia, but no patients needed                                   three of these patients suffered only from mild OSA, two
reintubation. These complications appeared within two                                     being obese and one having a craniofacial malformation.
hours after the surgical intervention.                                                    Moreover, 4 patients required reintubation and mechanical
In the group of patients with comorbidities, desaturations                                ventilation due to laryngospasm, bronchospasm, or pulmo-
occurred in all cases, and more severe postoperative nadir                                nary oedema, showing the more severe nature of complica-
oxygen desaturations were noted compared to patients with-                                tions in this subgroup.


Table II. Clinical characteristics of patients.
                                                                        Total                   Patients with                 Patients without           p-value
                                                                                                comorbidities                  comorbidities
 Number                                                                  577                          24                              553
 Boys/girls, N (%)                                                     357/220                       15/9                           342/211                0.99
                                                                     (61.9/38.1)                  (62.5/37.5)                     (61.8/38.2)
 Age, years                                                           5.0 ± 2.5                    4.5 ± 2.1                       5.1 ± 2.5              0.33
 AHI, events/hour                                                   4.0 (2.0-8.7)               12.9 (4.9-24.4)                  4.0 (2.0-8.2)           < 0.001
 OSA severity groups, N (%)                                                                                                                              < 0.001
   Mild                                                                  343                        7 (29.2)                      336 (60.8)
   Moderate                                                              112                        2 (8.3)                       110 (19.9)
   Severe                                                                122                       15 (62.5)                      107 (19.3)
 Postoperative complications, N (%)                                                                                                                      < 0.001
   Yes                                                                25 (4.3)                     14 (58.3)                       11 (2.0)
   No                                                                552 (95.7)                    10 (51.7)                      542 (98.0)
Data are expressed as mean ± standard deviation or median (interquartile range). AHI: apnoea-hypopnoea index; OSA: obstructive sleep apnoea




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P. Benedek et al.




Association of PoRCs with clinical parameters                                first-line treatment for paediatric OSA. Previous studies
Twenty-five patients had PoRCs, among whom 9 suffered                        have clearly demonstrated an increased risk of PoRCs in
from mild, 1 from moderate and 15 from severe OSA.                           patients with OSA, but the incidence was variable in these
When all subjects were analysed together, AHI (β = 0.044)                    cohorts. Jaryszak and colleagues found it to be 15.2% in
and the presence of comorbidities (β = 4.047) were inde-                     2011 9, Kou et al. recorded a 7.4% rate among 30,617 pa-
pendently associated with PoRCs (both p < 0.001). Ac-                        tients 20 and the meta-analysis by Saur et al. reported it to
cording to stepwise analysis, the presence of a comorbidity                  be 5.8% 21. In our cohort, the respiratory complication rate
was more strongly related to the risk of complications than                  was 4.3%.
OSA severity (β = 4.234).                                                    The American Academy of Otolaryngology Head and Neck
In patients with comorbidities, no significant difference                    Surgery Society (AAO-HNS), the American Academy of
was observed in OSA severity or BMI [AHI values (8.2                         Pediatrics (AAP) and European Respiratory Society (ERS)
(3.8-50.2) events/hour vs. 14.3 (11.7-23.3) events/hour,                     all highlight the severity of OSA (AHI) as a risk factor for
p = 0.37, Fig. 2], BMI (20.7 ± 4.9 vs 18.0 ± 4.6 kg/m2,                      PoRC 11, 22. Rhodes and colleagues found that in otherwise
p = 0.20), preoperative nadir O2 saturation (74% ± 18%                       healthy patients with OSA the risk for postoperative res-
vs 78% ± 15%, p = 0.57) and oxygen desaturation index                        piratory complications increases only in extremely severe
[5.9 (4.8-41.8) events/hour vs 12.5 (7.5-22.8) events/hour,                  cases (AHI > 50/h) 23. In our study population, we found a
p = 0.67] between cases with and without complications.                      significant correlation between OSA severity and PoRCs
In contrast, in patients without comorbidities, AHI was                      only in patients without comorbidity. Notably, in the group
increased in patients with PoRCs [14.7 (3.4-51.3) events/
                                                                             of patients without comorbidity and PoRCs the AHI was
hour vs 3.9 (2.0-8.0) events/hour, p < 0.001] (Fig. 3). Us-
                                                                             14.7 (3.4-51.3 events/hour), which was substantially lower
ing stepwise approach, AHI was the most strongly related
                                                                             than in the studies mentioned above. All complications in
factor to complications (β = 0.037, p = 0.004). None of
                                                                             this group were mild and occurred within the first 2 hours
the other parameters investigated were associated with the
                                                                             after the intervention.
incidence of PoRCs (all p > 0.05).
                                                                             Our data show that comorbidity plays an important role
                                                                             in the development of postoperative respiratory complica-
Discussion                                                                   tions. In our study, the most common comorbidity factors
OSA is a common medical condition in childhood as well                       were obesity, craniofacial malformations, prematurity and
as in adulthood, and can lead to fatal consequences without                  hypotonic neuromuscular disorder. Beyond the structural
treatment 1. Fortunately, these occur only rarely, but in gen-               factors, decreased neuromuscular tone and regulation dis-
eral OSA significantly and adversely affects the child’s life.               turbances can also lead to the development of OSA. After
In most cases the symptoms and consequences of OSA are                       adenotonsillectomy, oedema and anaesthetic-induced re-
reversible after adenotonsillectomy, which is considered                     duction in the pharyngeal muscle tone can cause serious




Figure 2. Postoperative oxygen desaturation in patients with PoRCs*. Data    Figure 3. AHI* values in relation to complications and comorbidities. Data
are expressed as mean ± standard deviation. *PoRCs: postoperative respira-   are shown as median with interquartile range. *AHI: apnoea-hypopnoea in-
tory complications.                                                          dex.



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                                                                     Postoperative complications in children with obstructive sleep apnoea




apnoeas and desaturations, which are more severe than in        effect of different comorbidities on PoRC and to develop
otherwise healthy children 24. Of note, we did not divide co-   an evidence-based, child-specific, reliable, postoperative
morbidities into separate groups, as these were composed        monitoring system.
of relatively low number of subjects individually. To see
if different comorbidities pose different amount of risk on     Conclusions
PoRCs further studies are warranted.
In our study, PoRCs occurred in 58.3% of patients with          Our data show that comorbidities significantly increase
comorbidity compared with the otherwise healthy group,          the risk for pulmonary complications after adenotonsil-
where this complication rate was 2%. We did not find a sig-     lectomy in children with OSA, and these complications
nificant difference in AHI values between the complication      are more severe than in patients with OSA but without
and non-complication subgroups in patients with comor-          comorbidities. Pulmonary complications occur with in-
bidity. Our results clearly demonstrate that these complica-    creased OSA severity in patients without comorbidities,
tions are more severe than in patients without comorbidity,     but complications usually occur within the first 2 hours
with more patients requiring reintubation and mechanical        postoperatively and these patients do not need intensive
ventilation.                                                    care observation. In children with comorbidities post-
Furthermore, there was a higher incidence of comorbidity        operative complications could also arise in cases of mild/
among patients who had mild or moderate OSA and suf-            moderate OSA. Therefore, postoperative monitoring
fered from postoperative respiratory complications. This        protocols should be adjusted to follow different patient
suggests that considering AHI alone is not sufficient to pre-   groups after adenotonsillectomy.
dict complications; other factors such as the presence of
comorbidity are also likely to influence complications to       Conflict of interest statement
varying degrees. These results support our suggestion that      Andras Bikov is supported by the NIHR Manchester BRC.
all OSA patients with a comorbidity (independent of the         The other authors declare no conflict of interest.
severity of the OSA) should be monitored thoroughly in the
post-anaesthesia care unit (PACU) or even in a paediatric       Funding
intensive care unit (PICU) for the first night after surgery.   This research did not receive any specific grant from fund-
In our study, the most severe complications were found in       ing agencies in the public, commercial, or not-for-profit
patients with mild or moderate sleep apnoea and comor-
                                                                sectors.
bidity.
Analysing data with PoRCs, 40% of these patients had
                                                                Authors’ contributions
mild and moderate OSA. Among these, 70% were afflicted
                                                                All authors have contributed to the concept of the study and
by comorbidity and 30% were otherwise healthy children.
                                                                they have read, critically reviewed and approved the final
Although most cases with mild/moderate OSA and compli-
                                                                version of the manuscript. Additional roles include: PB:
cations suffered from comorbidity conditions, 30% had no
                                                                designed the study, collected the data, performed the data
medical issues, yet PoRCs developed in those cases as well.
Patients without comorbidity suffered from desaturations        analyses and wrote the manuscript, ZL: performed the data
and needed supplemental oxygen. All of these complica-          analyses wrote and revised the manuscript, FK: collected
tions happened less than 2 hours after surgery. Our results     the data, discussed the manuscript, GK (Gabriella Kiss)
suggest that when PoRCs are observed, it should be recom-       collected the data, discussed the manuscript, BCS analysed
mended to monitor otherwise healthy children for a mini-        the data, ZB, GK (Gábor Katona), LR, AB: contributed to
mum of 2 hours after surgery independently of OSA sever-        the concept and design of the investigation and revision of
ity, but it can be managed at the ward or recovery room         the manuscript.
with oximetry by a trained nurse.
It is important to optimise the perioperative management        Ethical consideration
of children undergoing tonsillectomy through multidisci-        Ethics approval was obtained by the Ethics Committee at
plinary evaluation (e.g. anaesthesiology, otolaryngology,       Heim Pál National Institute of Paediatrics (6/2015 Heim
paediatrics and sleep medicine) 25. The limitation of our       Pál National Institute of Paediatrics). The study protocol
study was the low event rate in the comorbid group, espe-       conformed to the ethical guidelines of the Declaration of
cially in subgroup analyses, due to the single centre data      Helsinki updated in 2013 as reflected in an a priori approval
collection setting. An international, multicentre, observa-     by the institution’s human research committee. All caregiv-
tional trial is crucially needed for proper evaluation of the   ers signed a written informed consent.



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P. Benedek et al.




References                                                                           ing of Sleep and Associated Events. Deliberations of the Sleep Apnea
                                                                                     Definitions Task Force of the American Academy of Sleep Medicine.
1
     Gipson K, Lu M, Kinane TB. Sleep-disordered breathing in children.              J Clin Sleep Med 2012;8:597-619. https://doi.org/10.5664/jcsm.2172
     Pediatr Rev 2019;40:3-13. https://doi.org/10.1542/pir.2018-0142            14
                                                                                     Marcus CL, Omlin KJ, Basinki DJ, et al. Normal polysomnographic
2
     Marcus CL, Brooks LJ, Draper KA, et al. Diagnosis and manage-                   values for children and adolescents. Am Rev Respir Dis 1992;146:1235-
     ment of childhood obstructive sleep apnea syndrome. Pediatrics                  1239. https://doi.org/10.1164/ajrccm/146.5_Pt_1.1235
     2012;130:576-584. https://doi.org/10.1542/peds.2012-1671                   15
                                                                                     Brodsky L. Modern assessment of tonsils and adenoids, Pedi-
3
     Iannella G, Magliulo G, Maniaci A, et al. Olfactory function in                 atr Clin North Am 1989;36:1551-1569. https://doi.org/10.1016/j.
     patients with obstructive sleep apnea: a meta-analysis study. Eur               jsmc.2009.04.007
     Arch Otorhinolaryngol 2021;278:883-891. https://doi.org/10.1007/
     s00405-020-06316-w
                                                                                16
                                                                                     Benedek P, Kiss G, Csábi E, et al.. Obstruktív alvási apnoe szin-
                                                                                     drómában szenvedő gyermekek posztoperatív monitorozása [Postop-
4
     Csábi E, Benedek P, Janacsek K, et al. Sleep disorder in childhood              erative monitoring of children with obstructive sleep apnea syndrome].
     impairs declarative but not nondeclarative forms of learning. J Clin            Orv Hetil 2014;155:703-707. https://doi.org/10.1556/OH.2014.29879
     Exp Neuropsychol 2013;35:677-685. https://doi.org/10.1080/138033
     95.2013.815693
                                                                                17
                                                                                     Faul F, Erdfelder E, Lang AG, et al. G*Power 3: a flexible statistical
                                                                                     power analysis program for the social, behavioral, and biomedical sci-
5
     Galindo Torres BP, De Miguel García F, Whyte Orozco J. Tonsillec-               ences. Behav Res Methods 2007;39:175-191. https://doi.org/10.3758/
     tomy in adults: analysis of indications and complications. Auris Nasus          bf03193146
     Larynx 2018;45:517-521. https://doi.org/10.1016/j.anl.2017.08.012
                                                                                18
                                                                                     Youshani AS, Thomas L, Sharma R. Day case tonsillectomy for the
6
     Hill CA, Litvak A, Canapari C, et al. A pilot study to identify pre-            treatment of obstructive sleep apnoea syndrome in children: Alder
     and peri-operative risk factors for airway complications following
                                                                                     Hey experience. Int J Pediatr Otorhinolaryngol 2011;75:207-210.
     adenotonsillectomy for treatment of severe pediatric OSA. Int J Pedi-
                                                                                     https://doi.org/10.1016/j.ijporl.2010.10.036
     atr Otorhinolaryngol 2011;75:1385-1390. https://doi.org/10.1016/j.
     ijporl.2011.07.034
                                                                                19
                                                                                     Lam DJ, Jensen CC, Mueller BA, et al. Pediatric sleep apnea and
                                                                                     craniofacial anomalies: a population-based case-control study. Laryn-
7
     Patino M, Sadhasivam S, Mahmoud M. Obstructive sleep apnoea in
                                                                                     goscope 2010;120:2098-2105. https://doi.org/10.1002/lary.21093
     children: perioperative considerations. Br J Anaesth 2013;111(Suppl
     1):i83-i95. https://doi.org/10.1093/bja/aet371                             20
                                                                                     Kou YF, Sakai M, Shah GB, et al. Postoperative respiratory com-
8
     Jaryszak EM, Shah RK, Vanison CC, et al. Polysomnographic vari-                 plications and racial disparities following inpatient pediatric tonsil-
     ables predictive of adverse respiratory events after pediatric adenoton-        lectomy: a cross-sectional study. Laryngoscope 2019;129:995-1000.
     sillectomy. Arch Otolaryngol Head Neck Surg 2011;137:15-18. htt-                https://doi.org/10.1002/lary.27405
     ps://doi.org/10.1001/archoto.2010.226                                      21
                                                                                     Saur JS, Brietzke SE. Polysomnography results versus clinical factors
9
     Pace A, Iannella G, Rossetti V, et al. Diagnosis of obstructive sleep           to predict post-operative respiratory complications following pediat-
     apnea in patients with allergic and non-allergic rhinitis. Medicina             ric adenotonsillectomy. Int J Pediatr Otorhinolaryngol 2017;98:136-
     (Kaunas) 2020;56:454. https://doi.org/10.3390/medicina56090454                  142. https://doi.org/10.1016/j.ijporl.2017.05.004
10
     Statham MM, Elluru RG, Buncher R, et al. Adenotonsillectomy for
                                                                                22
                                                                                     Roland PS, Rosenfeld RM, Brooks LJ, et al. Clinical practice guide-
     obstructive sleep apnea syndrome in young children: prevalence                  line: polysomnography for sleep-disordered breathing prior to ton-
     of pulmonary complications. Arch Otolaryngol Head Neck Surg                     sillectomy in children. Otolaryngol Head Neck Surg 2011;145(1
     2006;132:476-480. https://doi.org/10.1001/archotol.132.5.476                    Suppl):S1-S15. https://doi.org/10.1177/0194599811409837
11
     Kaditis AG, Alonso Alvarez ML, et al. Obstructive sleep dis-
                                                                                23
                                                                                     Rhodes CB, Eid A, Muller G, et al. A. postoperative monitor-
     ordered breathing in 2- to 18-year-old children: diagno-                        ing following adenotonsillectomy for severe obstructive sleep ap-
     sis and management. Eur Respir J 2016;47:69-94. https://doi.                    nea. Ann Otol Rhinol Laryngol 2018;127:783-790. https://doi.
     org/10.1183/13993003.00985-2017                                                 org/10.1177/0003489418794700
12
     Benedek P, Balakrishnan K, Cunningham MJ, et al. International             24
                                                                                     Ehsan Z, Mahmoud M, Shott SR, et al. The effects of anesthesia
     Pediatric Otolaryngology group (IPOG) consensus on the diagnosis                and opioids on the upper airway: a systematic review. Laryngoscope
     and management of pediatric obstructive sleep apnea (OSA). Int J                2016;126:270-284. https://doi.org/10.1002/lary.25399.
     Pediatr Otorhinolaryngol 2020;138:110276. https://doi.org/10.1016/j.       25
                                                                                     Mitchell RB, Archer SM, Ishman SL, et al. Clinical practice
     ijporl.2020.110276                                                              guideline: tonsillectomy in children (update) – executive sum-
13
     Berry RB, Budhiraja R, Gottlieb DJ, et al. Rules for scoring respira-           mary. Otolaryngol Head Neck Surg 2019;160:187-205. https://doi.
     tory events in sleep: update of the 2007 AASM Manual for the Scor-              org/10.1177/0194599818807917




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