Effect of Anesthetic Technique on Postoperative Outcomes in Hip Fracture Repair

DORENE A. O’HARA, AMY DUFF, JESSE A. BERLIN, ROY M. POSES, VALERIE A. LAWRENCE, ELIZABETH C. HUBER, HELAINE NOVECK, BRIAN L. STROM AND JEFFREY L. CARSON Department of Anesthesiology and the Division of General Internal Medicine, Department of Medicine, University of Medicine and Dentistry of New Jersey, Robert Wood Johnson Medical School, New Brunswick, New Jersey Anesthesiology, 92: 947–957, 2000 The effects of anesthetic choice on postoperative mortality and morbidity were assessed in this retrospective cohort study of 9425 patients, aged 60 yr or older, who had surgical repair of hip fracture in 20 hospitals in the United States during 1983 to 1993. The primary outcome was death within 30 days of the procedure. Secondary outcomes were postoperative 7-day mortality, myocardial infarction, pneumonia, congestive heart failure, and change in mental status. Among the original cohort of 9589 patients, those receiving local anesthesia, a combination of regional and general anesthesia, or whose type of anesthesia was unknown were excluded. In the final study population, general anesthesia was used in 6206 patients; 3078 received spinal anesthesia and 141 received epidural anesthesia. The mean age of the patients was 80.3 yr and 78.7% were women. The group receiving regional anesthesia was older and somewhat more ill. The unadjusted 30-day mortality rate was 4.4% in the general anesthesia group and 5.4% in the regional anesthesia group. The adjusted odds ratio for general anesthesia versus regional anesthesia for the 7-day mortality was 0.90. None of the morbidity outcomes were associated with the type of anesthesia after adjusting for risk factors. Intraoperative hypotension, use of vasopressors, and intraoperative arrhythmia occurred more commonly in the regional anesthesia group than in the general anesthesia group. The adjusted odds ratios for general anesthesia versus regional anesthesia were 1.17 for myocardial infarction, 1.04 for congestive heart failure, 1.21 for pneumonia, and 1.08 for change in mental status. This study was unable to demonstrate that regional anesthesia was associated with better outcome than was general anesthesia in this large population of elderly patients. Choice of anesthesia should depend on factors other than the influence of any associated risks of postoperative mortality or morbidity. Comment: This kind of study is exceedingly difficult to undertake and rather surprisingly found that regional anesthesia was not superior to general anesthesia. One of the benefits of regional anesthesia in this setting is arguably easier pain control after operation and this aspect isn’t considered. The paper is accompanied by an extremely useful editorial by Baker, a mathematical statistician, about statistical considerations in randomized and nonrandomized clinical studies 1 that reviews different clinical study designs. The study is an observational one so the question posed here is how reliable are the results? This point is explored in the editorial. I find it impossible to say; however, it is exceedingly difficult to evaluate data from a study without random allocation to either regional or general anesthesia groups. Anthony P. Adams M.B. B.S. Ph.D. F.R.C.A. F.A.N.Z.C.A.