///2019 Abstract Details
2019 Abstract Details2019-07-13T07:45:15-05:00

Prevention hypotension after spinal anesthesia for cesarean section: systematic review and a network meta-analysis

Abstract Number: T2B-143
Abstract Type: Original Research

Stephen H Halpern MD, MSc, FRCPC1 ; John Fitzgerald MB FRCA2; Kelly Fedoruk MD FRCPC3; Sandra M Jadin MD4; Clarita Margarido MD5; Brendan Carvalho MBBCh, FRCA, MDCH6

Introduction: Hypotension is common after spinal anesthesia and may lead to maternal and fetal compromise. Strategies to reduce the incidence of hypotension include the use of prophylactic vasopressors and volume loading. This network meta-analysis compares, using direct and indirect evidence, multiple interventions and rank them according to probable efficacy. This is not possible with standard meta-analysis with pairwise comparisons.

Methods: We sought (RCTs) in women undergoing spinal anesthesia for elective CS. We included interventions that increased intravascular volume and vasopressors. Comparators also included placebo, and we excluded trials that treated rather than prevented hypotension. The primary outcome was the incidence hypotension . Secondary outcomes were nausea, tachycardia, bradycardia and reactive hypertension; Apgar scores and umbilical cord pH. Using Stata 15.1, we set up a network of all possible direct and indirect comparisons and generated a network map (Fig 1), and reviewed for consistency and inconsistency. We determined the probable ranking of each intervention, from best to worst of all treatments as calculated by the surface under the cumulative ranking (SUCRA) curves. Using random effects models, relative risk and standardized mean difference were used to compare dichotomous and continuous variables respectively.

Results: We retrieved 168 RCTs and used 101 studies comprised of 7390 patients for this analysis. 12 treatment options were compared. The network was not inconsistent (p=0.29). Vasopressors scored consistently better in hypotension prevention than fluid-loading techniques(Table 1). Pairwise analysis showed no statistically significant differences between vasopressors except phenylephrine was better than ephedrine(p=0.038). Colloid was more effective than crystalloid (p=0.000). Crystalloid was similar to placebo (p=0.83) Vasopressors were more efficacious in preventing nausea than fluids. There were no differences in among treatments for any other outcomes.

Conclusion: Vasopressors are more effective than fluid loading to reduce the incidence of hypotension, findings consistent with the recommendations of the recent consensus practice guidelines. Crystalloid preload or coload is not effective. These findings should be used to guide practice change.

Reference: Anaesthesia 2018;73:71

SOAP 2019