Ondansetron and Dexamethasone for Prevention of PDPH, Nausea, and Vomiting

Overview

This prospective, randomized, double-blind, placebo-controlled study was conducted at the Obstetrics and Gynecology Department of El-Minia University Hospital from October 2018 to October 2019. It enrolled 150 parturients aged 18-45 years undergoing elective cesarean section under spinal anesthesia. Participants were randomly assigned to one of three groups to receive either 8 mg IV ondansetron, 8 mg IV dexamethasone, or 5 mL of IV normal saline 5 minutes before spinal anesthesia. The primary objective was to evaluate the effectiveness of prophylactic ondansetron and dexamethasone in reducing the incidence of postdural puncture headache (PDPH). Secondary outcomes included severity and duration of PDPH, incidence and severity of nausea and vomiting, hemodynamic parameters, and neonatal Apgar scores. Ethical approval was obtained and verbal informed consent was collected from all participants.

This study is a single-center, prospective, randomized, double-blind, placebo-controlled clinical trial conducted to evaluate the efficacy of prophylactic intravenous administration of ondansetron and dexamethasone in reducing the incidence and severity of postdural puncture headache (PDPH), and postoperative nausea and vomiting (PONV), in parturients undergoing elective cesarean section under spinal anesthesia. A total of 150 parturients (ASA I or II), scheduled for cesarean delivery at Minia University Hospital, were randomly allocated into three parallel groups (1:1:1 ratio) using computer-generated randomization with sealed opaque envelopes to conceal allocation. All patients received standard spinal anesthesia with 0.5% hyperbaric bupivacaine via a 25-gauge Quincke spinal needle in the sitting position at the L3-L4 or L4-L5 interspace. Prior to spinal anesthesia, patients in: Group A (Ondansetron group) received 8 mg ondansetron IV (diluted to 5 mL in saline), Group B (Dexamethasone group) received 8 mg dexamethasone IV (diluted to 5 mL), Group C (Control group) received 5 mL of 0.9% normal saline IV. Study drugs were administered 5 minutes prior to the intrathecal injection. Blinding was maintained for patients, anesthesiologists, and outcome assessors. PDPH was assessed for 7 days postoperatively. A standardized questionnaire and the Corbey scale were used to evaluate headache onset, severity, duration, and need for analgesics. Nausea and vomiting were assessed intraoperatively and postoperatively (up to 48 hours). Standard antiemetic rescue therapy was available as needed. The protocol adhered to CONSORT guidelines and was approved by the Minia University Faculty of Medicine Research Ethics Committee. All participants provided written informed consent prior to enrollment. This trial investigates whether prophylactic ondansetron or dexamethasone, individually, can significantly reduce PDPH and PONV compared to placebo. The results are expected to inform perioperative management and enhance maternal outcomes in cesarean section under spinal anesthesia.