The Effect of Environmental Temperature on Airway Resistance in the Asthmatic Child

Abstract

ExtractTo test the hypothesis that receptors to cold are in the upper air passages, the effect of a change in environmental temperature from a high of 90-95° F to a low of 50-55° F was studied in a group of eight children with a history of chronic asthma before and after applying topical anesthesia to nose and pharynx; nine children without cardiac or pulmonary disease served as control subjects. The forced expiratory volume in 1 sec (FEVi), the maximum voluntary ventilation (MVV), and the maximum expiratory flow rates at 50% (VBO) and 25% (V25) of the vital capacity were used to assess airflow resistance. In the untreated asthmatic there was a significant fall in all test values at the low temperature (P < 0.01), which indicated an increase in airflow resistance. When nose and pharynx of the asthmatic patients were sprayed with lidocaine before decrease of the environmental temperature, there was no significant difference in test results (P > 0.05). These results offer additional evidence in support of the reflex nature of cold-induced bronchoconstriction with cold-sensitive receptors present in the upper airways. Speculation

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

“…Consistent with these findings, there are reports indicating that cooling of the nasal cavity, and thus the inhalation of cold air through the nose, could induce bronchoconstriction [5,6,18]. In our study, however, tidal nasal breathing of subfreezing air without cooling the skin of the face had no effect on FEV1.…”

“…The set-up allowing nasal breathing of subfreezing air without cooling the rest of the body was thought to be of importance, since there is evidence to suggest the existence of cold or airflow-sensitive receptors in the nasal cavity [5,6,16,17]. Consistent with these findings, there are reports indicating that cooling of the nasal cavity, and thus the inhalation of cold air through the nose, could induce bronchoconstriction [5,6,18].…”

“…Cooling the nasal cavity by spraying freons into the nose has been found to cause bronchoconstriction [5]. Consistently, nasopharyngeal anaesthesia has been found to inhibit the bronchoconstriction induced by cold ambient air [6]. In addition, a small bronchoconstriction can be induced by cooling the skin of the face by ice packs [7][8][9].…”

Effect of lignocaine, sodium cromoglycate, and ipratropium bromide in exercise-induced asthma

“…ipratropium bromide were 38 1% (5-0), 34.5% (6-1), 11-3% (3)(4)(5)(6)(7), and 19-3% respectively. Similarly, the mean maximal falls in MMFR after saline, lignocaine, sodium cromoglycate, and ipratropium bromide were 54 4% (5-2), 52 9% (7 7), 23-6% , and 32-1% (10(5) respectively.…”

Inhaled lignocaine does not alter bronchial hyperresponsiveness to hyperventilation of dry cold air in asthmatic subjects

“…Rodriguez-Martinez ct al. [9] showed that inhaled lignocaine could block bronchoconstriction due to inhalation of cool air, although they provide no information on the level of ventilation of their subjects at rest. In all the reported studies, only the maximum bronchoconstrictor effect of exercise or hyperventilation was used in the analysis of results as compared, in the present study, with a standardized index (PDim) derived from the dose response curve for which the between-day reproducibility has previously been assessed [13].…”