Falls and major orthopaedic surgery with peripheral nerve blockade: a systematic review and meta-analysis

The objective of this systematic review with meta-analysis was to determine the risk for falls after major orthopaedic surgery with peripheral nerve blockade. Electronic databases from inception through January 2012 were searched. Eligible studies evaluated falls after peripheral nerve blockade in adult patients undergoing major lower extremity orthopaedic surgery. Independent reviewers working in duplicate extracted study characteristics, validity, and outcomes data. The Peto odds ratio (OR) with 95% confidence intervals (CIs) were estimated from each study that compared continuous lumbar plexus blockade with non-continuous blockade or no blockade using a fixed effects model. Ten studies (4014 patients) evaluated the number of falls as an outcome. Five studies did not contain comparison groups. The meta-analysis of five studies [four randomized controlled trials (RCTs) and one cohort] compared continuous lumbar plexus blockade (631 patients) with non-continuous blockade or no blockade (964 patients). Fourteen falls occurred in the continuous lumbar plexus block group when compared with five falls within the non-continuous block or no block group (attributable risk 1.7%; number needed to harm 59). Continuous lumbar plexus blockade was associated with a statistically significant increase in the risk for falls [Peto OR 3.85; 95% CI (1.52, 9.72); P=0.005; I(2)=0%]. Evidence was low (cohort) to high (RCTs) quality. Continuous lumbar plexus blockade in adult patients undergoing major lower extremity orthopaedic surgery increases the risk for postoperative falls compared with non-continuous blockade or no blockade. However, attributable risk was not outside the expected probability of postoperative falls after orthopaedic surgery.