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.

Inclusion Criteria

• Female patients aged 18 to 45 years

• Body Mass Index (BMI) between 23-27 kg/m²

• American Society of Anesthesiologists (ASA) physical status I or II

• Scheduled for elective cesarean section under spinal anesthesia Exclusion Criteria

• Refusal to participate

• Conversion to general anesthesia due to failed spinal block

• Known hypersensitivity to ondansetron or dexamethasone

• Contraindications to study medications, including:

  • Diabetes mellitus
  • Active infection
  • Prolonged QT interval

• History of tobacco or drug use

• Coagulopathy or localized infection at the spinal injection site

• High-risk pregnancy (e.g., preeclampsia, placenta previa)

• History of chronic headache or migraine

Females of childbearing age undergoing elective cesarean section under spinal anesthesia

De-identified individual participant data (IPD) related to primary and secondary outcomes will be made available upon reasonable request from qualified researchers for academic purposes. Data will be shared beginning 6 months after publication and available for up to 2 years.

IPD will be available beginning 6 months after publication and ending 2 years after publication

Data will be available to qualified researchers whose proposed use of the data has been approved by an independent review committee. Requests should be directed to the principal investigator via institutional contact.

This was a double-blind study. Both the patients and the care providers (anesthesiologists) were blinded to the group assignments. Study medications were prepared in identical 5 mL syringes labeled A, B, or C by an independent supervisor who was not involved in patient care, drug administration, or data collection. Neither the participants nor the medical staff administering the anesthesia or assessing outcomes were aware of the group allocations