Prevention of hypotension after neuraxial anesthesia in nonobstetric surgery: a systematic review

Hypotension occurs frequently during neuraxial anesthesia and is associated with increased risks of perioperative complications. We sought to conduct a systematic review and meta-analysis of randomized controlled trials that evaluated interventions intended to mitigate exposure to intraoperative hypotension and prevent complications following the administration of neuraxial anesthesia for major nonobstetric noncardiac surgery.

We searched MEDLINE, Embase, PubMed®, and the Cochrane Controlled Register of Trials (database inception to 2 August 2023) for randomized controlled trials (RCTs) that evaluated interventions intended to reduce hypotension during neuraxial anesthesia in major noncardiac nonobstetric surgery, without any restrictions on the comparator type. The outcomes of interest were any measure of intraoperative hypotension (e.g., incidence, duration) and postoperative complications.

Among 33 included RCTs (n = 3,880) evaluating six classes of interventions, interventions that reduced the risk of hypotension included colloid preload (vs crystalloid, risk ratio [RR], 0.48; 95% confidence interval [CI], 0.30 to 0.80; P = 0.004; I² = 12%; very-low-certainty evidence) and prophylactic ondansetron (vs placebo; RR, 0.64; 95% CI, 0.53 to 0.78; P < 0.001; I² = 39%; moderate-certainty evidence). Prophylactic ephedrine was also associated with reduced time spent in hypotension. Nevertheless, crystalloid preloading did not reduce risks of hypotensive events compared with no preload (RR, 1.36; 95% CI, 0.96 to 1.92; P = 0.09; I² = 0%; very-low-certainty evidence). There were no compelling data showing that these interventions reduced the risks of complications.

Several interventions hold promise for mitigating exposure to hypotension following neuraxial anesthesia, albeit supported by very-low to moderate-certainty evidence. It remains unclear whether these interventions reduce the risks of postoperative complications.

PROSPERO ( CRD42022336197 ); first submitted 29 May 2022.