Evidence-based guidelines for fixing broken hips

To the Editor: Chilov and colleagues have presented an updated set of guidelines for management of hip fracture, which included the statement “regional anaesthesia is recommended for most patients”.1 The evidence for this recommendation was graded as Level I (National Health and Medical Research Council) and was supported by a single reference, namely a systematic review from the Cochrane Database by Parker et al.2

Parker et al performed a meta-analysis of the published trials examining the effect of regional versus general anaesthesia on a variety of outcomes after surgery for hip fracture. A possible difference in 1-month mortality was found in favour of regional anaesthesia, but this difference was borderline using one statistical model (relative risk, 0.7; 95% CI, 0.5–1.0) and non-significant using another model. There was no significant difference in mortality at 3 months or 1 year, and no significant difference in a variety of other outcomes. Appropriately, the authors concluded that “both regional and general anaesthesia produce comparable results and therefore anaesthetists should choose which technique is most appropriate for each individual patient”.2

One of the many difficulties in interpreting meta-analyses of regional anaesthesia is that most of the published trials were performed some decades ago. For example, one study that contributed a large proportion of the data within the Cochrane meta-analysis was conducted between 1980 and 1982, and patients were explicitly excluded if they were receiving low-dose anticoagulation therapy.3 The relevance of such trials to patients receiving general anaesthesia today is highly questionable, given the improvements in general anaesthetic drugs and techniques and the importance now placed on routine thromboprophylaxis.

There is a wide range of opinion within the specialty of anaesthesia regarding the place of major regional blockade, with little outcome-based evidence to support any particular advantage of these techniques. Although medical practitioners can benefit greatly from the efforts of reviewers to develop guidelines based on the best available evidence, care must be taken to ensure that recommendations do not go beyond what is supported by available data. Particular care needs to be taken when recommendations are made for areas of practice outside the reviewers’ expertise. The authors of these guidelines might consider withdrawing their recommendation regarding choice of anaesthesia.