Esophageal temperature during exercise in asthmatic and nonasthmatic subjects

TLDR

We measured rectal and esophageal temperatures during exercise in asthmatic and normal subjects breathing air at subfreezing, ambient, and body temperatures, while recording pulmonary mechanics before and after exercise. Asthmatic subjects exhibited the greatest airway obstruction after exercise with cold air and no response at body temperatures, whereas normal subjects showed no postexercise changes; both groups had identical retrotracheal cooling, suggesting asthmatics are more responsive to incompletely conditioned air.

Abstract

We measured the temperature in the rectum and two esophageal sites (retrocardiac and retrotracheal) during exercise in eight asthmatic and six normal subjects while they breathed air at subfreezing, ambient, and body conditions. Various aspects of pulmonary mechanics were recorded before and after exercise. The asthmatic subjects developed the greatest airway obstruction following exercise with cold air and no response at body conditions. There were no changes in pulmonary mechanics in the postexercise period in the normal individuals with any of the inspired air conditions. Despite these divergent mechanical responses retrotracheal temperatures fell by the same magnitude below core values in both groups of subjects, indicating that identical degrees of airway cooling occurred. We conclude that rather than having a defect in the ability to condition inspired air, asthmatic subjects are more responsive to the effects of incompletely conditioned air.