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.

In reply: We thank McCulloch for his comments regarding the use of regional anaesthesia in the surgical management of hip fracture. He makes the point that surgical and anaesthetic techniques have improved and implies that the advantage seen for regional anaesthesia in published studies may no longer be present. Given that controversy still exists, we would recommend that further randomised controlled trials be conducted. However, for the following reasons, we stand by our recommendation that the available evidence supports the use of regional anaesthesia for most patients with this condition.

Our current recommendation is unchanged from the earlier version of the guideline (published in the Journal in 1999),1 and is also consistent with at least one other published guideline.2 A number of the concerns raised by McCulloch were addressed in the response to a letter by another correspondent after the publication of the original guidelines.3

While we acknowledge that the review by Parker et al4 only found the reduction in mortality at 1 month to be of borderline significance, when our review team reassessed the original articles using the Cochrane Collaboration protocol we reached a summary odds ratio for mortality of 0.68 (95% CI, 0.49–0.96). With time and further studies we expect that this estimate of effect will become more precise as the power of the meta-analysis is increased. This view is supported by a systematic review of all randomised studies comparing regional anaesthesia with general anaesthesia across surgical specialties. The study of Rodgers et al found a statistically significant reduction in mortality (odds ratio, 0.70; 95% CI, 0.54–0.90) when regional anaesthesia was compared with general anaesthesia.5 This overall point estimate is very similar to that of Parker et al in their meta-analysis of patients with hip fracture. Although lack of power meant that statistical significance did not exist within individual surgical specialties, there was, in fact, little difference in the effect across surgical groups, with no significant heterogeneity between studies.

Serious complications of regional anaesthesia (eg, spinal haematoma) are extremely rare, as shown in the recent PEP study in Australia and New Zealand that reported no cases in 4603 patients undergoing regional blockade.6 This should be compared with the number needed to treat with regional anaesthesia to prevent one death of 38, according to the data of Parker et al.4

There is no doubt that our recommendation needs to be considered in the context of individual patient characteristics and, while the recommendation may not apply to all patients with hip fracture, we feel that the available evidence supports the use of regional anaesthesia.