Regional versus general anaesthesia in elderly patients undergoing surgery for hip fracture: protocol for a systematic review.

BACKGROUND: With an ageing population, the incidence of hip fractures requiring surgery is increasing. Post-operative delirium is common following hip fracture surgery. Delirium is associated with high mortality and morbidity, poor long-term functional outcomes and institutionalisation. There is some evidence to suggest that perioperative intervention, specifically the anaesthetic technique employed, may reduce the incidence of delirium in this population. The aim of this systematic review is to investigate the impact of anaesthesia type on post-operative delirium.

METHOD: We will conduct a systematic literature review using Embase, MEDLINE, CINAHL and the Cochrane Library (CENTRAL) bibliographic databases and the ZETOC and Web of Science websites. Authors of these trials will be invited to contribute unpublished data. PROSPERO register and clinical trial registers will also be searched to identify any ongoing reviews and trials. Eligible studies will assess the incidence of post-operative delirium in patients having regional or general anaesthesia for hip fracture surgery. The primary outcome of interest will be post-operative delirium; secondary outcomes will include mortality, measures of functional outcome, quality of life, length of hospital stay, discharge location and adverse events. Two reviewers will independently screen references identified by electronic literature searches. Two independent reviewers will extract data from studies fulfilling our inclusion criteria using a piloted data extraction form. Methodological quality and bias of included randomised controlled trials will be assessed using the 'Cochrane Collaborations tool for assessing risk of bias'; for non-randomised studies, this will be assessed using the Newcastle-Ottawa scale. Data on similar outcomes will be pooled when possible. Where possible, meta-analysis will be undertaken using Review Manager (RevMan version 5.3) software.

DISCUSSION: This systematic review will provide an updated evidence base with which to guide clinical practice and research for this group of challenging patients. If the anaesthetic technique employed is shown to reduce the incidence of post-operative cognition dysfunction, then this may lead to a change in evidence-based practice, influence future guidelines and support further randomised controlled trial research. There is no known effective treatment for delirium, creating the urgent need for research into delirium prevention.

SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42015020166.