title: Low-dose ketamine with multimodal postcesarean delivery analgesia: a randomized controlled trial.
abstract: BACKGROUND
  Ketamine at subanesthetic doses has analgesic properties that have been shown to reduce postoperative pain and morphine consumption. We hypothesized that intravenous ketamine 10mg administered during spinal anesthesia for cesarean delivery, in addition to intrathecal morphine and intravenous ketorolac, would decrease the incidence of breakthrough pain and need for supplemental postoperative analgesia.
  
  
  METHODS
  Using a randomized double-blind placebo-controlled design, healthy women scheduled for cesarean delivery receiving hyperbaric spinal bupivacaine, fentanyl and morphine were randomized to intravenous ketamine 10mg or saline following delivery. Postoperative analgesia included scheduled ketorolac and acetaminophen/hydrocodone tablets as needed for breakthrough pain. The primary outcome was the incidence of breakthrough pain in the first 24h. Secondary outcomes included the number of acetaminophen/hydrocodone tablets administered and numeric rating scale for pain (0-10).
  
  
  RESULTS
  Group characteristics did not differ. There was no difference in the incidence of breakthrough pain (ketamine 75% VS. saline 74%, P=0.86). There was no difference in 24-h or 72-h use of supplemental acetaminophen/hydrocodone tablets between groups. Pain scores in the first 24h were similar, but lower in the ketamine compared to the saline group 2weeks postpartum (difference -0.6, 95% CI -1.1 to -0.9).
  
  
  CONCLUSIONS
  We found no additional postoperative analgesic benefit of low-dose ketamine during cesarean delivery in patients who received intrathecal morphine and intravenous ketorolac. Subjects who received ketamine reported lower pain scores 2weeks postpartum.
authors.affiliation: Department of Anesthesiology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA.
authors.forename: J R
authors.initials: JR
authors.lastname: Bauchat
authors.forename: N
authors.initials: N
authors.lastname: Higgins
authors.forename: K G
authors.initials: KG
authors.lastname: Wojciechowski
authors.forename: R J
authors.initials: RJ
authors.lastname: McCarthy
authors.forename: P
authors.initials: P
authors.lastname: Toledo
authors.forename: C A
authors.initials: CA
authors.lastname: Wong
mesh_terms: D000328:Adult; D016362:Analgesia, Obstetrical; D016058:Analgesia, Patient-Controlled; D000701:Analgesics, Opioid / Q000008:administration & dosage / Q000627:therapeutic use; D000775:Anesthesia, Spinal; D000778:Anesthetics, Dissociative / Q000008:administration & dosage / Q000009:adverse effects; D002585:Cesarean Section; D005260:Female; D006213:Hallucinogens / Q000494:pharmacology; D006801:Humans; D007231:Infant, Newborn; D007275:Injections, Intravenous; D007649:Ketamine / Q000008:administration & dosage / Q000009:adverse effects; D008238:Lysergic Acid Diethylamide / Q000494:pharmacology; D010149:Postoperative Pain / Q000188:drug therapy; D011247:Pregnancy; D011595:Psychomotor Agitation / Q000523:psychology; D018401:Sample Size; D011795:Surveys and Questionnaires
chemical_list: D000701:Analgesics, Opioid; D000778:Anesthetics, Dissociative; D006213:Hallucinogens; D007649:Ketamine; D008238:Lysergic Acid Diethylamide