Blood gas in exercise-induced bronchospasm: a review.

Exercise-induced bronchospasm (EIB) in some cases of asthma is related to hypocapnia, hypoxemia, and acidosis, but studies have shown that children do not develop as abnormal PCO2, PO2, or pH levels with the induction of EIB. Gradient changes of alveolar-arterial oxygen differences reveal ventilation perfusion abnormalities existing at the onset of exercise in those patients who do develop EIB.