The effect of anesthetic technique on postoperative outcomes in hip fracture repair

Background The impact of anesthetic choice on postoperative mortality and m orbidity has not been determined with certainty. Methods: The authors evaluated the effect of type of anesthesia on postoper ative mortality and morbidity in a retrospective cohort study of consecutiv e hip fracture patients, aged 60 yr or older, who underwent surgical repair at 20 US hospitals between 1983 and 1993. The primary outcome was defined as death within 30 days of the operative procedure. The secondary outcomes were postoperative 7-day mortality, postoperative myocardial infarction, po stoperative pneumonia, postoperative congestive heart failure, and postoper ative change in mental status. Numerous comorbid conditions were controlled for individually and by several comorbidity indices using logistic regress ion. Results: General anesthesia was used in 6,206 patients (65.8%) and regional anesthesia in (3,219 patients 3,078 spinal anesthesia and 141 epidural ane sthesia). The 30-day mortality rate in the general anesthesia group was 4.4 %, compared with 5.4% in the regional anesthesia group (unadjusted odds rat io = 0.80; 95% confidence interval = 0.66-0.97). However, the adjusted odds ratio for general anesthesia increased to 1.08 (0.84-1.38). The adjusted o dds ratios for general anesthesia versus regional anesthesia for the 7-day mortality was 0.90 (0-59-1.39) and for postoperative morbidity outcomes wer e as follows: myocardial infarction: adjusted odds ratio = 1.17 (0.80-1.70) ; congestive heart failure: adjusted odds ratio = 1.04 (0.80-1.36); pneumon ia: adjusted odds ratio = 1.21 (0.87-1.68); postoperative change in mental status: adjusted odds ratio = 1.08 (0.95-1.22). Conclusions: The authors were unable to demonstrate that regional anesthesi a was associated with better outcome than was general anesthesia in this la rge observational study of elderly patients with hip fracture. These result s suggest that the type of anesthesia used should depend on factors other t han any associated risks of mortality or morbidity.