Hypotension (MeSH: D007022)NCT07883772
Prophylactic Ondansetron and Maternal Hemodynamics During Spinal Anesthesia for Elective Cesarean Section
A study testing Ondansetron in people with Hypotension (MeSH: D007022) and Bradycardia, run by Aydin Adnan Menderes University at 1 site in Turkey (Türkiye).
Trial summary
Spinal anesthesia is the preferred technique for elective cesarean section, but it is frequently complicated by maternal hypotension and bradycardia. Activation of serotonin type 3 (5-hydroxytryptamine type 3; 5-HT3) receptors on cardiac vagal afferent nerves has been proposed as one mechanism of the Bezold-Jarisch… Read more about this study
- Who is it for?
- Ages 18 to 45 years, women only
- Conditions the study is for
- Hypotension (MeSH: D007022), Bradycardia
- What is being tested?
- Ondansetron
- Type of treatment
- Injection or infusion
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 66 participants
- Where
- 1 siteTurkey (Türkiye)
- Study dates
- 16 Apr 2021to 16 Apr 2022
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 45 years
- Women only
- No healthy volunteers
- Adult
Who may be able to join
- Women aged 18-45 years
- American Society of Anesthesiologists (ASA) physical status I-II
- Singleton pregnancy
- Scheduled for elective caesarean section under spinal anaesthesia
- Written informed consent
Who cannot join
- Emergency caesarean section
- Planned general anaesthesia
- Contraindication to regional anaesthesia
- Multiple pregnancy
- Pre-eclampsia
- Any coexisting maternal disease other than diet-controlled gestational diabetes mellitus
Show all 9Show fewer
- Active or preterm labour
- Rupture of membranes
- Placenta previa
Trial locations and contacts
1 site in 1 country.
Turkey (Türkiye)1 site
Aydin Adnan Menderes University Hospital, Department of Anaesthesiology and Reanimation
Aydin, EFELER, 09004
About this study
Official title: Effect of Prophylactic Intravenous Ondansetron 4 mg on Maternal Hypotension, Bradycardia and Atropine Requirement During Spinal Anesthesia for Elective Cesarean Section: a Randomized, Double-blind, Placebo-controlled Trial
Spinal anesthesia is the preferred technique for elective cesarean section, but it is frequently complicated by maternal hypotension and bradycardia. Activation of serotonin type 3 (5-hydroxytryptamine type 3; 5-HT3) receptors on cardiac vagal afferent nerves has been proposed as one mechanism of the Bezold-Jarisch reflex, which may contribute to sudden bradycardia and vasodilation after spinal anesthesia. Ondansetron is a selective 5-HT3 receptor antagonist.
This randomized, double-blind, placebo-controlled trial evaluated whether a single intravenous (IV) dose of ondansetron 4 mg given 5 minutes before spinal anesthesia reduces maternal hypotension, bradycardia and the need for rescue medications (ephedrine and atropine) in women undergoing elective cesarean section. Hemodynamic variables and the pulse oximetry-derived perfusion index (PI) and pleth variability index (PVI) were recorded at predefined time points, including during a passive leg raising (PLR) maneuver before spinal anesthesia.
Read the detailed description
Design and setting: This was a single-center, prospective, randomized, double-blind, placebo-controlled, parallel-group trial conducted at Aydin Adnan Menderes University Hospital, Aydin, Turkiye, between 16 April 2021 and 16 April 2022. The study was approved by the institutional clinical research ethics committee on 15 April 2021 (protocol no. 2021/02). Written informed consent was obtained from all participants before randomization.
Randomization and blinding: Participants were allocated in a 1:1 ratio using a computer-generated randomization sequence and sequentially numbered, sealed, opaque envelopes. An anesthesiologist not involved in patient care or data collection prepared the study drug (ondansetron 4 mg or 0.9% sodium chloride) in identical 2-milliliter (mL) syringes. Patients, the anesthesiologists performing spinal anesthesia and deciding on rescue treatment, and the investigators recording outcomes were blinded to group allocation.
Procedure: Baseline measurements were obtained with the torso elevated to 45 degrees and the legs horizontal. Passive leg raising (PLR) was then performed (torso horizontal, legs raised to 45 degrees), and measurements were repeated after at least 1 minute. The study drug was administered intravenously (IV), and 5 minutes later spinal anesthesia was performed in the sitting position at the third-fourth lumbar (L3-L4) interspace with a 25-gauge Quincke needle using 10 milligrams (mg) of hyperbaric bupivacaine. Left uterine displacement was applied after the patient was positioned supine. A sensory block level of at least the tenth thoracic dermatome (T10) was required before surgery. Lactated Ringer's solution (planned total volume 2500 mL) was infused from spinal anesthesia until the end of surgery. Oxygen was given at 4 liters per minute via face mask.
Monitoring: Non-invasive blood pressure was measured every 3-4 minutes after spinal anesthesia. Systolic blood pressure (SBP), heart rate (HR), perfusion index (PI) and pleth variability index (PVI) were recorded at baseline, during PLR, at 1, 5, 8, 12 and 15 minutes after spinal anesthesia, and after delivery. PI and PVI were measured with a Masimo Root monitor using a sensor placed on the right thumb.
Definitions and rescue treatment: Hypotension was defined as a decrease in SBP to less than 80% of the baseline value and was treated with 5 mg IV ephedrine boluses. Bradycardia was defined in the protocol as an HR below 45 beats per minute and was treated with 0.5 mg IV atropine; atropine could also be given at the clinical discretion of the blinded attending anesthesiologist.
Sample size: Based on a previously published randomized trial of ondansetron 4 mg in parturients undergoing cesarean section, in which vasopressor requirement was 42.3% with saline and 7.7% with ondansetron, 29 patients per group were required to detect this difference with a two-sided alpha of 0.05 and 80% power (with continuity correction). Allowing for approximately 10% dropout, 33 patients per group (66 in total) were randomized.
- Conditions
- Hypotension (MeSH: D007022), Bradycardia
- Being tested
- Ondansetron, Placebo (0.9% sodium chloride)
- Keywords
- ondansetron, Serotonin 5-HT3 receptor antagonist, Bezold-Jarisch reflex, Spinal anesthesia, Cesarean section, Spinal anesthesia-induced hypotension, Perfusion index, Pleth variability index, Passive leg raising
- Medical subject headings
- Hypotension, Bradycardia
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
OndansetronDrug
A single intravenous (IV) dose of ondansetron 4 milligrams (mg) in 2 milliliters (mL), administered 5 minutes before spinal anesthesia.
Placebo (0.9% sodium chloride)Drug
A single intravenous (IV) dose of 2 milliliters (mL) of 0.9% sodium chloride, administered 5 minutes before spinal anesthesia in a syringe identical in appearance to the active drug.
| Study group | Role | What they receive |
|---|---|---|
| placebo(saline) | Placebo comparator | Participants received 2 milliliters (mL) of 0.9% sodium chloride intravenously (IV) 5 minutes before spinal anesthesia. Receives: Drug: Placebo (0.9% sodium chloride) |
| Ondansetron 4 mg | Experimental | Participants received ondansetron 4 milligrams (mg) in 2 milliliters (mL) intravenously (IV) 5 minutes before spinal anesthesia. Receives: Drug: Ondansetron |
What is being measured
The primary outcome is the main question the study is designed to answer.
Incidence of maternal hypotension
Number of participants with hypotension, defined as a decrease in systolic blood pressure to less than 80% of the baseline value.
Measured: From spinal anaesthesia to 15 minutes after spinal anaesthesia
Secondary outcomes (9)
Atropine requirement
Number of participants who received intravenous atropine 0.5 mg.
Measured: From spinal anaesthesia to the end of surgery
Incidence of bradycardia
Number of participants with heart rate below 45 beats/min.
Measured: From spinal anaesthesia to 15 minutes after spinal anaesthesia
Total ephedrine dose
Cumulative dose of intravenous ephedrine (mg) administered to treat hypotension.
Measured: From spinal anaesthesia to the end of surgery
Systolic blood pressure
Systolic blood pressure (mmHg) measured non-invasively.
Measured: Baseline, during passive leg raising, 1, 5, 8, 12 and 15 minutes after spinal anaesthesia, and after delivery
Heart rate
Heart rate (beats/min).
Measured: Baseline, during passive leg raising, 1, 5, 8, 12 and 15 minutes after spinal anaesthesia, and after delivery
Perfusion index (PI)
Perfusion index measured with a Masimo Root monitor using a sensor on the right thumb.
Measured: Baseline, during passive leg raising, 1, 5, 8, 12 and 15 minutes after spinal anaesthesia, and after delivery
Pleth variability index (PVI)
Pleth variability index measured with a Masimo Root monitor using a sensor on the right thumb.
Measured: Baseline, during passive leg raising, 1, 5, 8, 12 and 15 minutes after spinal anaesthesia, and after delivery
Ability of PLR-induced changes in PI and PVI to predict post-spinal hypotension
Area under the receiver operating characteristic curve (AUC) of the change in PI and PVI from baseline to passive leg raising for discriminating participants who developed hypotension.
Measured: Baseline and during passive leg raising (before spinal anaesthesia)
Apgar score at 1 and 5 minutes after delivery
Neonatal condition assessed with the Apgar score at 1 and 5 minutes after delivery. The Apgar score evaluates five components (heart rate, respiratory effort, muscle tone, reflex irritability and skin color), each scored from 0 to 2. The total score ranges from a minimum of 0 to a maximum of 10, with higher scores indicating a better outcome.
Measured: 1 and 5 minutes after delivery
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted20 Oct 2026
- Study start16 Apr 2021
- Primary completion16 Apr 2022
- Study completion16 Apr 2022
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for Hypotension (MeSH: D007022)Studies of the same condition, open and under way.
- More trials run by Aydin Adnan Menderes UniversityThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Quadruple blind
- Who is masked
- Participant, Care provider, Investigator, Outcomes assessor
- Enrolment
- 66 participants (actual)
Sponsor and investigators
- Lead sponsor
- Aydin Adnan Menderes University
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, MURAT DEMİRCİOGLU, Aydin Adnan Menderes University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07883772
- Sponsor's protocol ID
- 2021/02
- Other IDs
- Ethics Review
- Status last verified
- Oct 2026
- First submitted
- 13 Oct 2026
- Last updated
- 23 Oct 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Yes: De-identified individual participant data underlying the results reported in the published article (baseline characteristics, hemodynamic measurements, rescue medication use and neonatal Apgar scores) will be shared.
Publications
Sahoo T, SenDasgupta C, Goswami A, Hazra A. Reduction in spinal-induced hypotension with ondansetron in parturients undergoing caesarean section: a double-blind randomised, placebo-controlled study. Int J Obstet Anesth. 2012 Jan;21(1):24-8. doi: 10.1016/j.ijoa.2011.08.002. Epub 2011 Nov 18.
PubMed 22100822
Study at a glance
From the registry record, last updated by the sponsor on 23 Oct 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Effect of Prophylactic Intravenous Ondansetron 4 mg on Maternal Hypotension, Bradycardia and Atropine Requirement During Spinal Anesthesia for Elective Cesarean Section: a Randomized, Double-blind, Placebo-controlled Trial
- ClinicalTrials.gov ID
- NCT07883772
- Acronym / sponsor ID
- 2021/02
- Conditions
- Hypotension (MeSH: D007022), Bradycardia
- Keywords
- ondansetron, Serotonin 5-HT3 receptor antagonist, Bezold-Jarisch reflex, Spinal anesthesia, Cesarean section, Spinal anesthesia-induced hypotension, Perfusion index, Pleth variability index
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 66 participants (actual)
- Lead sponsor
- Aydin Adnan Menderes UniversityUniversity, hospital or other
- Study start
- 16 Apr 2021 (actual)
- Primary completion
- 16 Apr 2022 (actual)
- Study completion
- 16 Apr 2022 (actual)
- First posted
- 20 Oct 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Spinal anesthesia is the preferred technique for elective cesarean section, but it is frequently complicated by maternal hypotension and bradycardia. Activation of serotonin type 3 (5-hydroxytryptamine type 3; 5-HT3) receptors on cardiac vagal afferent nerves has been proposed as one mechanism of the Bezold-Jarisch reflex, which may contribute to sudden bradycardia and vasodilation after spinal anesthesia. Ondansetron is a selective 5-HT3 receptor antagonist.
This randomized, double-blind, placebo-controlled trial evaluated whether a single intravenous (IV) dose of ondansetron 4 mg given 5 minutes before spinal anesthesia reduces maternal hypotension, bradycardia and the need for rescue medications (ephedrine and atropine) in women undergoing elective cesarean section. Hemodynamic variables and the pulse oximetry-derived perfusion index (PI) and pleth variability index (PVI) were recorded at predefined time points, including during a passive leg raising (PLR) maneuver before spinal anesthesia.
Detailed description
Design and setting: This was a single-center, prospective, randomized, double-blind, placebo-controlled, parallel-group trial conducted at Aydin Adnan Menderes University Hospital, Aydin, Turkiye, between 16 April 2021 and 16 April 2022. The study was approved by the institutional clinical research ethics committee on 15 April 2021 (protocol no. 2021/02). Written informed consent was obtained from all participants before randomization.
Randomization and blinding: Participants were allocated in a 1:1 ratio using a computer-generated randomization sequence and sequentially numbered, sealed, opaque envelopes. An anesthesiologist not involved in patient care or data collection prepared the study drug (ondansetron 4 mg or 0.9% sodium chloride) in identical 2-milliliter (mL) syringes. Patients, the anesthesiologists performing spinal anesthesia and deciding on rescue treatment, and the investigators recording outcomes were blinded to group allocation.
Procedure: Baseline measurements were obtained with the torso elevated to 45 degrees and the legs horizontal. Passive leg raising (PLR) was then performed (torso horizontal, legs raised to 45 degrees), and measurements were repeated after at least 1 minute. The study drug was administered intravenously (IV), and 5 minutes later spinal anesthesia was performed in the sitting position at the third-fourth lumbar (L3-L4) interspace with a 25-gauge Quincke needle using 10 milligrams (mg) of hyperbaric bupivacaine. Left uterine displacement was applied after the patient was positioned supine. A sensory block level of at least the tenth thoracic dermatome (T10) was required before surgery. Lactated Ringer's solution (planned total volume 2500 mL) was infused from spinal anesthesia until the end of surgery. Oxygen was given at 4 liters per minute via face mask.
Monitoring: Non-invasive blood pressure was measured every 3-4 minutes after spinal anesthesia. Systolic blood pressure (SBP), heart rate (HR), perfusion index (PI) and pleth variability index (PVI) were recorded at baseline, during PLR, at 1, 5, 8, 12 and 15 minutes after spinal anesthesia, and after delivery. PI and PVI were measured with a Masimo Root monitor using a sensor placed on the right thumb.
Definitions and rescue treatment: Hypotension was defined as a decrease in SBP to less than 80% of the baseline value and was treated with 5 mg IV ephedrine boluses. Bradycardia was defined in the protocol as an HR below 45 beats per minute and was treated with 0.5 mg IV atropine; atropine could also be given at the clinical discretion of the blinded attending anesthesiologist.
Sample size: Based on a previously published randomized trial of ondansetron 4 mg in parturients undergoing cesarean section, in which vasopressor requirement was 42.3% with saline and 7.7% with ondansetron, 29 patients per group were required to detect this difference with a two-sided alpha of 0.05 and 80% power (with continuity correction). Allowing for approximately 10% dropout, 33 patients per group (66 in total) were randomized.
Study design
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Quadruple blind (participant, care provider, investigator, outcomes assessor)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| placebo(saline) | Placebo comparator | Drug: Placebo (0.9% sodium chloride)Participants received 2 milliliters (mL) of 0.9% sodium chloride intravenously (IV) 5 minutes before spinal anesthesia. |
| Ondansetron 4 mg | Experimental | Drug: OndansetronParticipants received ondansetron 4 milligrams (mg) in 2 milliliters (mL) intravenously (IV) 5 minutes before spinal anesthesia. |
Who may qualify
- Ages
- 18 to 45 years
- Sex
- Female only
- Healthy volunteers
- Not accepted
- Age groups
- Adult
Key inclusion criteria (5 listed)
- Women aged 18-45 years
- American Society of Anesthesiologists (ASA) physical status I-II
- Singleton pregnancy
- Scheduled for elective caesarean section under spinal anaesthesia
- Written informed consent
Key exclusion criteria (9 listed)
- Emergency caesarean section
- Planned general anaesthesia
- Contraindication to regional anaesthesia
- Multiple pregnancy
- Pre-eclampsia
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| OndansetronA single intravenous (IV) dose of ondansetron 4 milligrams (mg) in 2 milliliters (mL), administered 5 minutes before spinal anesthesia. | Drug | Ondansetron 4 mg |
| Placebo (0.9% sodium chloride)A single intravenous (IV) dose of 2 milliliters (mL) of 0.9% sodium chloride, administered 5 minutes before spinal anesthesia in a syringe identical in appearance to the active drug. | Drug | placebo(saline) |
Primary outcome
Incidence of maternal hypotension
Time frame: From spinal anaesthesia to 15 minutes after spinal anaesthesia
Number of participants with hypotension, defined as a decrease in systolic blood pressure to less than 80% of the baseline value.
9 secondary outcomes
Atropine requirement
Time frame: From spinal anaesthesia to the end of surgery
Incidence of bradycardia
Time frame: From spinal anaesthesia to 15 minutes after spinal anaesthesia
Total ephedrine dose
Time frame: From spinal anaesthesia to the end of surgery
Systolic blood pressure
Time frame: Baseline, during passive leg raising, 1, 5, 8, 12 and 15 minutes after spinal anaesthesia, and after delivery
Heart rate
Time frame: Baseline, during passive leg raising, 1, 5, 8, 12 and 15 minutes after spinal anaesthesia, and after delivery
Perfusion index (PI)
Time frame: Baseline, during passive leg raising, 1, 5, 8, 12 and 15 minutes after spinal anaesthesia, and after delivery
Pleth variability index (PVI)
Time frame: Baseline, during passive leg raising, 1, 5, 8, 12 and 15 minutes after spinal anaesthesia, and after delivery
Ability of PLR-induced changes in PI and PVI to predict post-spinal hypotension
Time frame: Baseline and during passive leg raising (before spinal anaesthesia)
Apgar score at 1 and 5 minutes after delivery
Time frame: 1 and 5 minutes after delivery
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 23 Oct 2026.
- Results publication: PubMed 22100822Sahoo T, SenDasgupta C, Goswami A, Hazra A. Reduction in spinal-induced hypotension with ondansetron in parturients undergoing caesarean section: a double-blind randomised, placebo-controlled study. Int J Obstet Anesth. 2012 Jan;21(1):24-8. doi: 10.1016/j.ijoa.2011.08.002. Epub 2011 Nov 18.
- Individual participant dataSharing planned: Yes. De-identified individual participant data underlying the results reported in the published article (baseline characteristics, hemodynamic measurements, rescue medication use and neonatal Apgar scores) will be shared.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Ondansetron in people with Hypotension (MeSH: D007022) and Bradycardia, run by Aydin Adnan Menderes University at 1 site in Turkey (Türkiye).
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 5 inclusion and 9 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 23 Oct 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Turkey (Türkiye). Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Incidence of maternal hypotension (time frame: From spinal anaesthesia to 15 minutes after spinal anaesthesia). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT07883772, which also lists 1 linked publication.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 23 Oct 2026.