Cold-induced bronchoconstriction: role of cutaneous reflexes vs. direct airway effects

摘要: To determine the relative contributions of direct airway vs. reflex cutaneous thermal receptor stimulation in cold-induced bronchoconstriction, we isolated these two aspects cold exposure 10 asthmatics and 13 normal subjects. Ice packs were applied to skin face, chest, thigh, upper arm random sequence while serially measuring specific conductance. In this fashion a limited mapping skin-mediated bronchoconstriction was established. Warm same areas control for any potential nonspecific stimulatory effects. Cooling induced similar degree both groups; effect very small, did not induce symptoms, only seen with face. At another time, subjects performed isocapnic hyperventilation frigid air ascertain their response cooling. A moderate but significant correlation existed between sensitivity; however, magnitude responses differed markedly. Breathing at rest had no on lung function; elevating ventilation promptly produced bronchial narrowing. Hence, environment, most potent stimulus development obstruction derives from effect.