Comparison of Intravenous Ondansetron and Low Dose Ketamine in Preventing Post Spinal Shivering

January 3, 2026 updated by: Adeel Ahmed, Mayo Hospital Lahore
This randomized controlled trial assessed whether intravenous ondansetron is more effective than low dose ketamine in preventing shivering after spinal anesthesia in adults undergoing elective surgery. Post spinal shivering is a frequent and uncomfortable complication of spinal anesthesia and may increase oxygen demand and interfere with routine monitoring. Adults aged 20 to 70 years (body weight 50 to 80 kg; American Society of Anesthesiologists class I to II) scheduled for elective procedures under standardized spinal anesthesia were randomly allocated in equal numbers to receive either ondansetron 8 mg intravenously or ketamine 0.25 mg/kg intravenously, administered 5 minutes after the spinal injection. Perioperative temperature management was standardized for all participants. The primary outcome was the occurrence of post spinal shivering during intraoperative monitoring. Among 180 participants, shivering occurred in 30.0% of those receiving ondansetron and 44.4% of those receiving ketamine, showing a statistically significant reduction with ondansetron.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Actual)

180

Phase

  • Not Applicable

Contacts and Locations

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

Study Locations

  • Pakistan
    • Punjab Province
      • Lahore, Punjab Province, Pakistan, 54000
        • Mayo Hospital, Lahore

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

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Patients of either gender aged 20-60 years with ideal body
  • weight of 50 to 80 kg.
  • Patients meeting ASA classification I and II determined by
  • anesthesiologist.
  • Patients undergoing elective surgeries under spinal anesthesia.
  • Duration of surgery should not be more than 3 hours.

Exclusion Criteria:

  • Patients having a documented history of severe adverse reactions to ketamine or ondansetron.
  • Patients with cardiovascular disease documented in history.
  • Patients with hepatic disease documented in history and supported by lab results (AST 32-40U/L), ALT(10-40U/L).
  • Patients with renal disease documented in history and supported by lab results. Urea (10-50mg/dl) S/Creatinine (0.3-1.5mg/dl).
  • Patients with hyperthyroidism documented in history and supported by lab results.
  • Patients with history of mental illness, seizures and glaucoma.
  • Patients with known hypertension (BP greater than 140/90).
  • Haemodynamically unstable patients (BP<100mmHg).
  • Patients with coagulopathy or other bleeding diathesis documented in history and supported by lab results.
  • Complicated prolonged surgeries in spinal anesthesia.

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: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Single

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Group Ondansetron
Received 8 mg of ondansetron administered intravenously five minutes after spinal anesthesia for prophylaxis of post spinal shivering.
Drug: ondansetron
8 mg ondansetron administered intravenously as a single dose five minutes after spinal anesthesia.
Other Names:
  • Serotonin type 3 receptor antagonist
Active Comparator: Group Low Dose Ketamine
Received ketamine 0.25 mg per kilogram administered intravenously five minutes after spinal anesthesia for prophylaxis of post spinal shivering.
Drug: Ketamine (0.25 mg/kg)
0.25 mg per kilogram ketamine administered intravenously as a single dose five minutes after spinal anesthesia.
Other Names:
  • N-methyl-D-aspartate receptor antagonist

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Frequency of Post Spinal Shivering
Time Frame: From 5 minutes after administration of study drug until transfer of the patient to the post-anesthesia care unit
Occurrence of post spinal shivering following administration of study medication, assessed clinically by the anesthesiology team and recorded as present or absent during intraoperative monitoring after spinal anesthesia.
From 5 minutes after administration of study drug until transfer of the patient to the post-anesthesia care unit

Collaborators and Investigators

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

Sponsor

Mayo Hospital Lahore

Investigators

  • Principal Investigator: Adeel Ahmed, Mayo Hospital Lahore

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)

January 1, 2020

Primary Completion (Actual)

June 30, 2020

Study Completion (Actual)

June 30, 2020

Study Registration Dates

First Submitted

January 3, 2026

First Submitted That Met QC Criteria

January 3, 2026

First Posted (Estimated)

January 12, 2026

Study Record Updates

Last Update Posted (Estimated)

January 12, 2026

Last Update Submitted That Met QC Criteria

January 3, 2026

Last Verified

January 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • Mayo1

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.

Clinical Trials on Postoperative Shivering

Clinical Trials on ondansetron

Search Similar Trials

Sponsors and Collaborators

Medical Conditions

Drug Interventions

CROs by country

CROs in United Kingdom

Conditions

Rare Diseases

Drug Interventions

Dietary Supplements

Sponsor/Collaborators

Locations

Subscribe