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

Status

Indicates the current recruitment status or the expanded access status.
Recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

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

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
120

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • 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 Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

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

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

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

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
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

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
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

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
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

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
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)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
July 30, 2026

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
January 1, 2027

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
January 2, 2027

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
July 27, 2026

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
July 29, 2026

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
July 31, 2026

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
October 1, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
September 30, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
September 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant 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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