Routine Antiemetic Prophylaxis for Nonfasted Parturients Undergoing Cesarean Sections Under Spinal Anesthesia

September 30, 2026 updated by: Tolga Karaçay, Sanliurfa Education and Research Hospital

Comparative Effectiveness of Routine Antiemetic Prophylaxis in Nonfasted Parturients Undergoing Cesarean Sections Under Spinal Anesthesia: A Prospective Randomized Controlled Trial

The aim of this prospective randomized double-blind study is to compare the effectiveness of routine antiemetic prophylaxis for the prevention of intraoperative nausea and vomiting (IONV) in non-fasted parturients undergoing emergency cesarean section under spinal anesthesia.

Nausea and vomiting are common complications during cesarean delivery performed under spinal anesthesia and may negatively affect maternal comfort and perioperative safety. The incidence of these symptoms may be particularly increased in emergency cesarean sections involving non-fasted (full-stomach) parturients. This study compares two commonly used antiemetic strategies, namely 5-hydroxytryptamine-3 (5-HT3) receptor antagonists and dopamine receptor antagonists, to determine their relative effectiveness in preventing IONV during surgery.

The findings are expected to contribute to optimization of antiemetic prophylaxis protocols, improvement of maternal comfort, and reduction of perioperative complications associated with nausea and vomiting during emergency cesarean delivery.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Detailed Description

This prospective, randomized, double-blind clinical trial is designed to evaluate the comparative effectiveness of routine antiemetic prophylaxis for preventing intraoperative nausea and vomiting in non-fasted parturients undergoing emergency cesarean section under spinal anesthesia.

Eligible participants will be pregnant women with American Society of Anesthesiologists (ASA) physical status I-II who undergo emergency cesarean delivery under spinal anesthesia. Only non-fasted (full-stomach) parturients will be included.

Exclusion criteria include ASA physical status III or higher, preoperative anemia, massive intraoperative hemorrhage, requirement for additional intraoperative hypnotic agents, known gastrointestinal disease, psychiatric disorders or psychotropic medication use, and administration of antiemetic medication within 24 hours before surgery.

Participants will be randomized using a sealed-envelope allocation method before arrival in the operating room. Before transfer to the operating room, patients will receive the assigned study medication according to the randomization protocol. Both patients and the attending anesthesiologist responsible for outcome assessment will remain blinded to group allocation.

Participants will receive one of the following prophylactic antiemetic regimens:

Group O: 5-HT3 receptor antagonist (e.g., ondansetron or equivalent agent) Group M: Dopamine receptor antagonist (e.g., metoclopramide)

Standard monitoring will include electrocardiography, non-invasive blood pressure measurement, and peripheral oxygen saturation (SpO₂). Following intravenous cannulation, Ringer's lactate infusion will be initiated.

Spinal anesthesia will be performed at the L4-L5 interspace using 10 mg hyperbaric bupivacaine. After block placement, patients will be positioned supine with left uterine displacement to minimize aortocaval compression. Supplemental oxygen will be administered via nasal cannula at 2 L/min.

All participants will receive prophylactic intravenous ephedrine 5 mg. Additional 5 mg boluses will be administered if systolic blood pressure decreases below 100 mmHg or more than 20% from baseline values. Intravenous atropine 0.5 mg will be administered in cases of bradycardia (heart rate below 50-60 beats/min).

Following delivery of the fetal shoulders, oxytocin 20 IU will be administered intravenously as an infusion.

Demographic and perioperative data including age, body mass index, fasting duration since last solid food intake, smoking status, and operative duration will be recorded.

Hemodynamic variables (blood pressure and heart rate) will be recorded every 2 minutes until delivery and every 5 minutes thereafter until completion of surgery.

Intraoperative nausea and vomiting will be assessed during three predefined periods:

From 5 minutes after spinal anesthesia until delivery During and immediately after delivery From delivery until skin closure

Severity of nausea and vomiting will be evaluated using the Bellville scoring system:

0 = No nausea

  1. = Nausea
  2. = Retching (gagging)
  3. = Vomiting

Primary Outcome

Incidence of intraoperative nausea and vomiting occurring during and immediately after delivery.

Secondary Outcomes

Incidence and severity of intraoperative nausea and vomiting during the other predefined assessment periods.

Postoperative complications associated with antiemetic therapy

Study Type

Interventional

Enrollment (Estimated)

120

Phase

  • Phase 4

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Locations

  • Turkey (Türkiye)
    • Eyyübiye
      • Sanliurfa, Eyyübiye, Turkey (Türkiye), 63040
        • Recruiting
        • Sanliurfa Education and Research Hospital
        • Contact:
        • Principal Investigator:
          • Servet Sürmeli, M.D.
        • Sub-Investigator:
          • Tolga Karaçay, M.D.
        • Sub-Investigator:
          • Serkan Solak, M.D.
        • Sub-Investigator:
          • Azer İlbengü Kaptan, M.D.

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

Female

Description

Inclusion Criteria:

  • Pregnant women scheduled for emergency cesarean delivery under spinal anesthesia
  • Non-fasted (full-stomach) parturients
  • American Society of Anesthesiologists (ASA) physical status I-II
  • Age ≥ 18 years
  • Singleton pregnancy
  • Ability to provide written informed consent

Exclusion Criteria:

  • ASA physical status III or higher
  • Refusal to participate
  • Elective cesarean delivery (non-emergency cases)
  • Preoperative antiemetic use within 24 hours before surgery
  • Known allergy or contraindication to study drugs (ondansetron or metoclopramide)
  • Pre-existing gastrointestinal disorders (e.g., severe GERD, gastroparesis, bowel obstruction)
  • Psychiatric illness or current use of psychotropic medications
  • Preoperative anemia (as defined by institutional threshold, e.g., Hb < 10 g/dL)
  • Intraoperative conversion to general anesthesia
  • Massive intraoperative hemorrhage (>1000-1500 mL or requiring transfusion, depending on your protocol definition)
  • Intraoperative administration of additional sedative or antiemetic agents outside study protocol
  • Multiple gestation pregnancies

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Prevention
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Double

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: 5-HT3 Receptor Antagonist Group

Participants undergoing emergency cesarean delivery under spinal anesthesia will receive prophylactic administration of a 5-HT3 receptor antagonist before surgery. Intraoperative and early postoperative nausea and vomiting will be assessed.
Drug: Ondansetron 4mg

Prophylactic intravenous administration of a 5-HT3 receptor antagonist prior to cesarean delivery under spinal anesthesia.
Experimental: Dopamine Receptor Antagonist Group

Participants undergoing emergency cesarean delivery under spinal anesthesia will receive prophylactic administration of a dopamine receptor antagonist before surgery. Intraoperative and early postoperative nausea and vomiting will be assessed.
Drug: metoclopramide

Prophylactic intravenous administration of a dopamine receptor antagonist prior to cesarean delivery under spinal anesthesia.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Incidence of Intraoperative Nausea and Vomiting Immediately After Fetal Delivery
Time Frame: Perioperative

Incidence of nausea, retching, or vomiting occurring during the immediate period following fetal delivery, assessed using the Bellville scoring system. From fetal delivery until uterine closure.
Perioperative

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Incidence of Intraoperative Nausea and Vomiting Between Spinal Anesthesia and Fetal Delivery
Time Frame: Perioperative

Incidence of nausea, retching, or vomiting occurring from initiation of spinal anesthesia until fetal delivery.From spinal anesthesia administration until fetal delivery.
Perioperative
Incidence of Intraoperative Nausea and Vomiting Immediately Before Fetal Delivery
Time Frame: Perioperative

Incidence of nausea, retching, or vomiting occurring in the late intraoperative period immediately preceding fetal delivery. From uterine incision to fetal delivery
Perioperative
Incidence of Intraoperative Nausea and Vomiting During Skin Closure
Time Frame: Perioperative

Incidence of nausea, retching, or vomiting occurring during surgical skin closure.
Perioperative
Postoperative Complications Related to Antiemetic Prophylaxis
Time Frame: Postoperative

Incidence of adverse effects associated with prophylactic antiemetic agents including headache, dizziness, hypotension, extrapyramidal symptoms, or sedation. From end of surgery through 24 hours postoperatively.
Postoperative

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sanliurfa Education and Research Hospital

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

July 30, 2026

Primary Completion (Estimated)

January 1, 2027

Study Completion (Estimated)

January 2, 2027

Study Registration Dates

First Submitted

July 27, 2026

First Submitted That Met QC Criteria

July 29, 2026

First Posted (Actual)

July 31, 2026

Study Record Updates

Last Update Posted (Actual)

October 1, 2026

Last Update Submitted That Met QC Criteria

September 30, 2026

Last Verified

September 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • HRÜ/26.07.15

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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