Effect of an upper respiratory tract infection on upper airway reactivity.

Patients presenting for elective anaesthesia and surgery may be suffering with, or recovering from, a recent upper respiratory tract infection (URTI). It is a frequent clinical problem as to whether to postpone surgery in such patients as they may be more likely to suffer adverse respiratory events related to administration of general anaesthesia. Using dilute ammonia vapour as a chemical stimulus, we measured upper airway reactivity in 11 healthy volunteers (six males), mean age 39.8 (range 30-58) yr, who had symptoms of an URTI. Volunteers were recruited 24-72 h after symptoms first began, and followed-up at regular intervals for the next 8 weeks. Measurements of upper airway reactivity were made on the following days (+/- 24h) after commencement of URTI symptoms: 3, 6, 9, 15, 20 and 27. Additional measurements were obtained 56 days after symptoms first began, and these were regarded as baseline measurements. Upper airway reactivity was increased on days 3, 6 and 9 compared with baseline measurements (P < 0.01, Wilcoxon). There was no significant change in airway reactivity from day 15 onwards, by which time 10 of the 11 subjects were completely devoid of symptoms. All subjects were asymptomatic by day 20 and remained so until the study ended on day 56. We conclude that upper airway reactivity was increased during the acute phase of an URTI, and that this appeared to be related to the presence of symptoms.