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

• Status: Completed
• Trial end date: 2008-10-01
• Target enrollment: 0
• Participant gender: Female

Summary

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.

• Phase: N/A
• Accepts Healthy Volunteers?: No

Details

• Lead Sponsor: Northwestern University
• Treatments: Ketamine; N-Methylaspartate

Criteria

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.