Vasopressors for the management of maternal hypotension during cesarean section under spinal anesthesia: A Systematic review and network meta-analysis protocol.

Background: Spinal anesthesia is the standard technique for elective cesarean section, but the incidence of maternal hypotension in this setting is reportedly about 80%, without any prophylactic management. Vasopressors are the most reliable method for counteracting the hypotension induced by spinal anesthesia. However, studies investigating the effects of vasopressors have yielded inconsistent and debatable results. Therefore, we plan to conduct a systematic review and network meta-analysis to identify the most effective vasopressor to prevent maternal hypotension, and to decrease fetal acidosis in women undergoing spinal anesthesia for elective cesarean section.
Methods: A systematic and comprehensive search to detect all the randomized controlled studies on vasopressors for the management of maternal hypotension during cesarean section under spinal anesthesia will be performed using information in the databases, MEDLINE, EMBASE, the Cochrane Central Register of Controlled Trials (CENTRAL), and Google Scholar, beginning from their inception to October 2018. We will conduct a network meta-analysis to combine the direct and indirect comparisons of the vasopressors. We will use the surface under the cumulative ranking curve (SUCRA) values and rankograms to present the hierarchy of vasopressors. A comparison-adjusted funnel plot will be used to assess the presence of small-study effects. The quality of the studies included will be assessed using the risk of bias tool. All statistical analyses will be performed using Stata SE version 15.0.
Ethics and Dissemination: This systematic review and meta-analysis will be published in a peer-reviewed journal. Ethical approval and informed consent are not required, as the study will be a literature review and will not involve direct contact with patients or alterations to patient care.
Trial Registration Number: The protocol for this review has been registered in the PROSPERO network (registration number: CRD42018111852).