Effect of anaesthesia on lung function in children with asthma

Spirometry was performed before operation, soon after recovery ("early") and the day after ("late") general anaesthesia for elective surgery in 20 children with asthma and 20 matched children without asthma. Pulse oximetry was recorded on the first postoperative night. The mean early peak expiratory flow rate (PEFR) decreased in the asthmatics by 19.91 (95% confidence intervals (CI) 10.84-28.97)% and in the controls by 19.25 (10.70-27.80)%. The mean early FEV1 decreased in the asthmatics by 16.02 (9.29-22.75)% and in the controls by 11.03 (2.86-19.19)%. The mean late decrease from baseline PEFR for the asthmatics was 18.55 (11.23-25.87)% but only 14.93 (7.89-21.97)% for the controls. The mean late FEV1 was 8.2 (0.83-15.56)% below baseline in the asthmatics but only 6.82 (-0.79 to 14.42)% in the controls. There were no differences in overnight pulse oximetry. We conclude that healthy children exhibited a decrease in FEV1 and PEFR after general anaesthesia for elective surgery, but this decline did not appear to be any greater in well controlled asthmatic children compared with children who did not have asthma.