Facial cooling, but not nasal breathing of cold air, induces bronchoconstriction: a study in asthmatic and healthy subjects

Abstract

Reflex-mediated bronchoconstriction in cold climates may be more important than it has previously been thought. This issue has seldom been studied using physiological methods. We wanted to investigate, using physiological methods, what triggers the bronchoconstriction occurring at cold ambient temperature during resting nasal ventilation: cooling of the skin of the face or cooling of the nasal cavity. Three experiments were carried out in 15 stable asthmatics and 10 healthy volunteers: 1) a whole-body exposure to subfreezing temperature in an environmental chamber, during which the subjects breathed cold air through the nose; 2) a similar exposure to subfreezing temperature except that the subjects now breathed warm air through the mouth from outside the chamber; and 3) nasal breathing of subfreezing air from a heat exchanger whilst the subjects sat at room temperature. Spirometric values and facial skin temperature were measured both during and after the exposures. Maximal decrements (means +/- standard errors) of forced expiratory volume in one second (FEV1) in experiments 1, 2 and 3 were: 5.8 +/- 0.8, 5.1 +/- 0.7 and 2.1 +/- 0.5%, respectively (p < 0.001). Only the two experiments in the environmental chamber induced significant bronchoconstriction. All responses were of similar magnitude in the asthmatic and the healthy subjects. The cooling of the skin of the face seems to be the trigger for the bronchoconstriction during resting nasal ventilation at cold ambient temperature both in asthmatic and nonasthmatic subjects.

Cold air-provoked respiratory symptoms: the mechanisms and management

“…This again highlights the physiological nature of the reflex responses to cold air. However, other investigators have not detected any changes in FEV 1 in response to nasal breathing of subfreezing air (20,23). This discrepancy may reflect different methods to cool the nose and to measure the bronchoconstriction.…”

“…Even subfreezing air is almost completely saturated and warmed to near body temperature when it has passed the nasal cavity (15,18,19). Therefore, at rest and during light exercise the possible trigger sites for cold air-provoked respiratory symptoms include the facial skin and the nasal mucosa but not the lower airways (20).…”

“…It has been known for decades that cooling of the facial skin by ice packs triggers slight bronchoconstriction in humans (84,85 o C ambient air combined with wind provokes an immediate 3-10 % fall in FEV 1 , in healthy subjects as well as in subjects with asthma and COPD (16,20,86). Thus, this response can be considered a physiological response to a physiological stimulus.…”

The unified immune system: Respiratory tract–nasobronchial interaction mechanisms in allergic airway disease

“…Others have suggested that facial cooling, and not nasal exposure, was responsible for the bronchoconstrictive effect of cold air. 69 Also, after nasal allergen provocation, no changes in FEV 1 values could be measured in patients with allergic rhinitis and asthma. 60,70 Nasal provocation with methacholine 71 and allergen 60,72 in patients with allergic rhinitis and asthma resulted in impaired airway function.…”

Climate change, extreme weather events, air pollution and respiratory health in Europe

“…Breathing cold air causes the cooling of nasal and bronchial mucosa, seriously impairing ciliary motility and consequently reducing the immune system's resistance to respiratory infections [107,108]. Exposure to cold air may also increase the number of granulocytes and macrophages in the lower airways in healthy subjects [109] and induce bronchoconstriction [110,111], suggesting that cold exposure could be involved in the pathogenesis of the asthma-like condition. Part of the increase in respiratory outcomes during cold periods may also be attributed to cross-infections from increased indoor crowding during winter [112].…”