Upper Airway Disorders

[摘要] PATHOPHYSIOLOGYLARYNGEAL CHANGES DURING EXERCISE AND EXERCISE-INDUCED ASTHMAHurbis CG, Schild JA. Ann Otol Rhinol Laryngol. 1992;100:34-37.Purpose of the StudyThis study was performed to determine the effect of exercise on the larynx in healthy and asthmatic patients.Study PopulationThirty subjects aged 18 to 35 years were studied. There were 15 healthy subjects and 15 with only exercise-induced asthma.MethodsAll subjects had an endoscopic examination of their laryngeal area where photographic images were recorded for measurement of inspiratory and expiratory glottic areas. All were then exercised at 75% to 85% of their predicted maximum heart rate for 8 minutes, breathing cold dry air. Laryngoscopy and pulmonary functions were performed after 8 minutes of exercise and again after 5 minutes of rest.FindingsIn healthy individuals and in asthmatic patients whose forced expiratory volume changed less than 5%, the laryngeal opening increased in size, whereas asthmatics whose forced expiratory volume dropped in excess of 5% showed a narrowing of the glottic area.ConclusionsThe normal enlargement of the glottic space allows for less resistance, making the increase of minute volume that is demanded by exercise less energy-intense. The moderate asthmatic, on the other hand, has a decrease in size to further increase the work of breathing. The benefits of such an increase may be an endogenous method to apply positive end-expiratory pressure, thus keeping airways open.CommentsAs I read this I couldn't help think of the asthmatic who is so hard to manage with laryngeal spasm. Perhaps these people have an exaggerated and prolonged physiologic response.

[学科分类] 儿科学