 In this situation, lactate dehydrogenase levels increase and gas exchange is compromised.Oxygen is less able to diffuse into the blood, leading to hypoxia, which along with high arterial carbon dioxide () levels, stimulates hyperventilatory effort, thereby causing dyspnea (breathlessness).The diagnosis can be confirmed by the characteristic appearance of the chest X-ray and an arterial oxygen level (PaO2) that is strikingly lower than would be expected from symptoms.