General versus spinal/epidural anaesthesia for surgery for hip fractures in adults.

BACKGROUND: The majority of hip fracture patients are treated surgically, requiring anaesthesia.
OBJECTIVES: To compare different types of anaesthesia for surgical repair of hip fractures (proximal femoral fractures) in adults. This is primarily regional (spinal or epidural) anaesthesia versus inhalation general anaesthesia, but also includes ketamine anaesthesia versus inhalation general anaesthesia. SEARCH STRATEGY: We searched the Cochrane Musculoskeletal Injuries Group trials register, Medline, selected orthopaedic and anaesthetic journals and conference proceedings, and reference lists of relevant articles. Date of the most recent search: August 1999. SELECTION CRITERIA: Randomised and quasi-randomised trials comparing different methods of anaesthesia for hip fracture surgery in skeletally mature persons. Trials comparing the use of local nerve blocks are not considered in this review. Neither are trials using different types of drugs or techniques with one type of anaesthesia. The primary outcome was mortality. DATA COLLECTION AND ANALYSIS: Two reviewers independently assessed trial quality, using a nine item scale, and extracted data. The other two reviewers independently checked these results. Wherever appropriate and possible, results were pooled. MAIN
RESULTS: Sixteen trials, involving 2191 patients, which compared regional anaesthesia with general anaesthesia, were included. All trials had methodological flaws. Regional anaesthesia was associated with a decreased mortality at one month (53/781(6.8%) versus 78/826(9.4%)) of borderline statistical significance (relative risk 0.72, 95% confidence interval 0.51 to 1.00)). The results for three month mortality were not statistically significant, although the confidence interval does not exclude the possibility of a clinically relevant reduction (86/726 (11.8%) versus 98/765 (12.8%), relative risk 0.92, 95% confidence interval 0.71 to 1.21). The reduced numbers at one year, coming exclusively from two studies, preclude any useful conclusions for long term mortality (80/354 (22.6%) versus 78/372 (21.0%), relative risk 1.07, 95% confidence interval 0.82 to 1.41). Regional anaesthesia was associated with a tendency to a longer operation (weighted mean difference 4.8 minutes, 95% confidence interval 1.1 to 8.6 minutes), and a reduced risk of deep venous thrombosis (39/129 (30%) versus 61/37(76%); relative risk 0.64, 95% confidence interval 0.48 to 0.86), although this conclusion is insecure due to possible selection bias in the subgroups in whom this outcome was measured. No other statistically significant differences in outcome were identified. There was insufficient evidence to draw any conclusions from a further two included trials, involving a total of 100 patients, which compared other types of anaesthesia. REVIEWER'S
CONCLUSIONS: Regional anaesthesia and general anaesthesia appear to produce comparable results for most of the outcomes studied. Regional anaesthesia may reduce short-term mortality but no conclusions can be drawn for longer term mortality.