Baricity of spinal bupivacaine and the incidence of hypotension in non-obstetric surgery: A systematic review.

Bupivacaine is commonly used for spinal anaesthesia. The baricity of bupivacaine (isobaric vs. hyperbaric) may influence the spread, level of the block and the subsequent haemodynamic effects of the spinal anaesthesia. This review considers the available literature on the effect of baricity on the haemodynamic sequelae of spinal anaesthesia with bupivacaine. A literature search was conducted of the MEDLINE and EMBASE databases up to February 2024, following PRISMA guidelines. Randomised controlled trials (RCTs) comparing isobaric and hyperbaric bupivacaine in non-obstetric surgeries were included. Ten studies comprising 586 patients were included. While the literature suggests a trend towards greater incidence of hypotension with hyperbaric bupivacaine, no statistically significant difference was found. Variations in bupivacaine doses and volumes, spinal techniques and definitions of hypotension hindered definitive conclusions. Lower doses relevant to current practice also remain underexplored.