PREVENTION OF RESPIRATORY COMPLICATIONS AFTER ABDOMINAL-SURGERY - A RANDOMIZED CLINICAL-TRIAL

Objective-To evaluate the prevention of respiratory complications afte r abdominal surgery by a comparison of a global policy of incentive sp irometry with a regimen consisting of deep breathing exercises for low risk patients and incentive spirometry plus physiotherapy for high ri sk patients. Design-Stratified randomised trial. Setting-General surgi cal service of an urban teaching hospital. Patients-456 patients under going abdominal surgery. Patients less than 60 years of age with an Am erican Society of Anesthesia classification of 1 were considered to be at low risk. Outcome measures-Respiratory complications were defined as clinical features consistent with collapse or consolidation, a temp erature above 38 degrees C, plus either confirmatory chest radiology o r positive results on sputum microbiology. We also recorded the time t hat staff devoted to prophylactic respiratory therapy. Results-There w as good baseline equivalence between the groups. The incidence of resp iratory complications was 15% (35/231) for patients in the incentive s pirometry group and 12% (28/225) for patients in the mixed therapy gro up (P=0.40; 95% confidence interval -3.6% to 9.0%). It required simila r amounts of staff time to provide incentive spirometry and deep breat hing exercises for low risk patients. The inclusion of physiotherapy f or high risk patients, however, resulted in the utilisation of an extr a 30 minutes of staff time per patient. Conclusions-When the use of re sources is taken into account, the most efficient regimen of prophylax is against respiratory complications after abdominal surgery is deep b reathing exercises for low risk patients and incentive spirometry for high risk patients.