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Does a Single Intravenous Dose of Ketamine Reduce the Need for Supplemental Opioids in Post-Cesarean Section Patients?

This study has been completed.
Information provided by (Responsible Party):
Cynthia Wong, Northwestern University Identifier:
First received: June 13, 2007
Last updated: March 17, 2014
Last verified: March 2014

Pain control after cesarean delivery is associated with improved breastfeeding and infant rooming-in times. In addition, inadequate analgesia leads to elevated plasma catecholamine concentrations, which negatively affect every organ system. There is growing evidence that ketamine, N-methyl-D-aspartate receptor antagonist, is efficacious when used as an adjuvant in postoperative pain control. A 2006 Cochrane Collaboration systemic review and meta-analysis concluded, "Ketamine in subanesthetic doses….is effective in reducing morphine requirements in the first 24 hours after surgery."

Ketamine's prolonged analgesic effect, despite its short half-life and its use in low doses, is theorized to be due to blockade of spinal cord central sensitization. Central sensitization is a phenomenon whereby repeated painful stimulus leads to more severe pain perception over time despite no change in the intensity of the painful stimulus.Ketamine may also prevent the development of acute opioid tolerance. Ketamine's analgesic effects have also demonstrated in the obstetric population. Post-cesarean delivery morphine requirements in women who received ketamine as part of a general anesthesia technique were decreased. Similary, low-dose ketamine in conjunction with bupivacaine-only spinal anesthesia reduced postoperative analgesic requirements compared to bupivacaine-only spinal anesthesia and bupivacaine-fentanyl spinal anesthesia.

In the United States, healthy women scheduled for elective cesarean delivery commonly receive spinal anesthesia with bupivacaine-fentanyl-morphine. To our knowledge, IV ketamine has not been studied as an adjuvant to this regimen in the analgesic management in post-cesarean delivery patients. Multimodal therapy for postoperative pain control is widely practiced due to the advantage it provides in blocking multiple pain pathways while minimizing side effects of each individual pain medication. We hypothesize that low dose intravenous ketamine will improve multi-modal post-cesarean analgesia compared to placebo. The purpose of this study is to evaluate this hypothesis and study the possible side effects of this regimen in combination with bupivacaine-fentanyl-morphine spinal anesthesia.

Condition Intervention
Ketamine Adverse Reaction
Effects of; Anesthesia, Spinal and Epidural, in Pregnancy
Complication of Labor and/or Delivery
Drug: Ketamine
Drug: Placebo

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double Blind (Participant, Care Provider, Investigator, Outcomes Assessor)
Primary Purpose: Treatment
Official Title: Does a Single Intravenous Dose of Ketamine Reduce the Need for Supplemental Opioids in Post-Cesarean Section Patients?

Resource links provided by NLM:

Further study details as provided by Northwestern University:

Primary Outcome Measures:
  • Number of Subjects Requiring Supplemental Analgesia in the First 24 Hours Following Cesarean Delivery [ Time Frame: 24 hours ]
    Request for oral hydrocodone/acetaminophen for pain not controlled by around the clock non-steroidal antiflammatory drugs in the first 24 hours following cesarean delivery.

Secondary Outcome Measures:
  • Verbal Pain Scores (0 to 10) at First Analgesia Request [ Time Frame: 24 hours ]
    Numeric rating of pain scores (NRS) scale (0 to 10) at time of supplemental analgesia request. Zero is no pain and 10 is worst pain imaginable.

  • Cumulative Hydrocodone/Acetaminophen for Supplemental Analgesia to Treat Breakthrough Pain [ Time Frame: 72 hours ]
    Cumulative hydrocodone/acetaminophen for supplemental analgesia to treat breakthrough pain for 72 hours following cesarean delivery

  • Postoperative Nausea [ Time Frame: 24 hours ]
    Number of subjects reporting nausea in first 24 hours following cesarean delivery

  • Postoperative Vomiting [ Time Frame: 24 hours ]
    Number of subjects that vomited in the first 24 hours following cesarean delivery

  • Postperative Pruritus [ Time Frame: 24 hours ]
    Number of subjects with pruritus in the first 24 hours following cesarean delivery

  • Disturbing Dreams [ Time Frame: 72 hours ]
    Number of subject reporting disturbing dreams at 72 hours post cesarean delivery

Enrollment: 188
Study Start Date: July 2006
Study Completion Date: October 2008
Primary Completion Date: October 2008 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: Ketamine
Subjects receive IV ketamine 10 mg 5 minutes after infant delivery.
Drug: Ketamine
Ketamine 10 mg diluted to 20 mL delivered over 10 minutes via an infusion pump set at 2ml/minute
Other Name: N-methyl-D-aspartate (NMDA)
Placebo Comparator: Placebo
Subjects receive IV Saline 20 mL 5 minutes after infant delivery
Drug: Placebo
Saline 20 mL IV infusion delivered over 10 minutes via an infusion pump set at 2ml/minute
Other Name: 0.9% Saline

  Show Detailed Description


Ages Eligible for Study:   18 Years to 60 Years   (Adult)
Sexes Eligible for Study:   Female
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • Eligible women are at term (≥37 week gestation),
  • Healthy,
  • ASA class 1-2,
  • Scheduled for elective cesarean section whose anesthetic plan is for spinal anesthesia with intrathecal morphine and intravenous ketorolac analgesia for post operative analgesia

Exclusion Criteria:

  • Women with American Society of Anesthesiologists physical status >2,
  • Body mass index ≥40 kg/m2,
  • Known allergy to any of the study medications,
  • Contraindication to the spinal anesthesia,
  • History of substance abuse,
  • History of hallucinations,
  • Chronic opioid therapy,
  • Chronic pain.
  Contacts and Locations
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Please refer to this study by its identifier: NCT00486902

United States, Illinois
Northwestern University
Chicago, Illinois, United States, 60611
Sponsors and Collaborators
Northwestern University
Principal Investigator: Cynthia A Wong, M.D. Northwestern University
  More Information

Kashefi P. The benefits of intraoperative small-dose ketamine on postoperative pain after cesarean section. Anesthesiology 2006;104, Supp 1.

Responsible Party: Cynthia Wong, Professor of Anesthesiology, Northwestern University Identifier: NCT00486902     History of Changes
Other Study ID Numbers: 0524-030
Study First Received: June 13, 2007
Results First Received: March 15, 2011
Last Updated: March 17, 2014

Keywords provided by Northwestern University:
Spinal Anesthesia

Additional relevant MeSH terms:
Obstetric Labor Complications
Pregnancy Complications
Sensory System Agents
Peripheral Nervous System Agents
Physiological Effects of Drugs
Anesthetics, Dissociative
Anesthetics, Intravenous
Anesthetics, General
Central Nervous System Depressants
Excitatory Amino Acid Antagonists
Excitatory Amino Acid Agents
Neurotransmitter Agents
Molecular Mechanisms of Pharmacological Action
Excitatory Amino Acid Agonists processed this record on April 28, 2017