///2016 Abstract Details
2016 Abstract Details2019-07-15T10:10:51-05:00

Reducing Spinal Anesthesia induced Hypotension during Cesarean Delivery with Serotonin Receptor Antagonists: a Meta-Analysis

Abstract Number: SA-14
Abstract Type: Original Research

Selina D Patel BMedSci, BMBS, FRCA1 ; Steve Haplern MD, MSc, FRCPC2; Wint Mon MBBS, FRCA3; Brendan Carvalho MBBCh, FRCA4; Pervez Sultan MBChB, FRCA5


Hypotension is the commonest complication associated with spinal anesthesia for cesarean delivery that can have deleterious effects for both mother and baby.(1) The objective of this meta-analysis was to determine the efficacy of serotonin (5-HT3) receptor antagonists at reducing hypotension associated with spinal anesthesia for cesarean delivery.


A literature search (Medline, Embase, CINAHL, Scopus and Pubmed) was performed to identify randomized controlled trials (RCTs) investigating the effect of prophylactic 5-HT3 antagonists on spinal-induced hypotension for cesarean delivery. The primary outcome was incidence of hypotension. Secondary outcomes included: dose of vasopressor used (phenylephrine equivalent), incidences of bradycardia, nausea, vomiting and pruritus. Odds ratios (OR) and mean differences (MD) were calculated using random effects modeling with 95% confidence interval.


Ten RCTs met our inclusion criteria. A total of 1096 patients were recruited in all study groups: 636 patients in the 5-HT3 group and 460 patients in the control group. The incidence of hypotension was significantly reduced in the 5-HT3 group compared to the placebo control group (OR 0.30 [0.13, 0.69]; p= 0.005). Administering prophylactic 5-HT3 antagonists also reduced the dose of phenylephrine needed (MD -230.98mcg [-384.05, -77.91mcg]; p= 0.003). The incidences of bradycardia, nausea and vomiting were also lower in the 5-HT3 group with ORs of 0.46 [0.23, 0.91]; p= 0.03, 0.22 [0.13, 0.36]; p<0.00001, and 0.27 [0.10- 0.75], p=0.01 respectively. Pruritus was similar in both groups.


Prophylactic use of serotonin receptor antagonists reduces the incidence of spinal-induced hypotension as well as the dose of vasopressor needed during cesarean delivery. Additional maternal benefits include reduction in nausea, vomiting and bradycardia. Findings confirm the potential efficacy of prophylactic ondansetron on reducing spinal anesthesia-induced hypotension,(2) and although further studies investigating any potential side effects from 5-HT3 antagonists are required, current evidence suggests routine use during cesarean delivery should be considered.


1) Cyna AM et al. Cochrane Database Syst Rev. 2006 Oct 18;(4):CD002251

2) Gao et al. Int J Obstet Anesth. 2015; 24:335–343

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