Lessons learned from a randomised controlled study of perioperative beta blockade in high risk patients undergoing emergency surgery

Background: Perioperative beta blockade has been shown to reduce mortality after major elective surgery. The aim of this study was to determine whether it could reduce the rate of death and morbidity from cardiac complications in high risk patients undergoing emergency surgery. Methods: Over a one-year interval all patients undergoing major non-elective orthopaedic or general surgery were screened to identify those at high risk of cardiac complications. Consenting, high risk patients were randomly allocated atenolol or placebo for seven days, commencing at anaesthetic induction. Deaths and cardiac complications within 30 days were recorded. Results: Some 2351 patients had an emergency operation; 145 were at high risk and eligible for the study. Of 89 patients approached, 57 initially consented. Only 38 patients, however, completed the study protocol, 19 were withdrawn. Of those who completed the study, 5/20 patients in the placebo group and 3/18 in the treatment group died before hospital discharge (p=0.520). Four others in the placebo group and two in the atenolol group had post-operative non-fatal cardiac events (positive troponin T), p=0.311. Conclusions: This study of emergency surgery proved more difficult than similar trials in elective surgery. The final study groups were small and there were no significant differences in outcomes. A much larger study is required for a definitive answer