title: The effect of low-dose intravenous ketamine on postoperative pain following cesarean section with spinal anesthesia: a randomized clinical trial.
abstract: OBJECTIVE
  Low-dose ketamine has been considered a good substitute for opioids for controlling postoperative pain. The purpose of this study was to determine the effect of low-dose intravenous ketamine following cesarean section with spinal anesthesia on postoperative pain and its potential complications.
  
  
  METHODS
  One hundred and sixty pregnant women volunteered to participate in this randomized controlled trial. Participants were randomly divided into two groups (n=80 for each group). Five minutes after delivery, the experimental group received 0.25mg/kg ketamine while the control group received the same amount of normal saline.
  
  
  RESULTS
  There was a significant difference between the two groups in the severity of pain at one, two, six, and 12 hours following surgery. Postoperative pain was significantly less severe in the experimental group. Compared to the control group, the experimental group felt pain less frequently and therefore asked for analgesics less often. On average, the number of doses of analgesics used for the participants in the experimental group was significantly less than the number of doses used for the control group. Analgesic side effects (including nausea, itching, and headache) were not significantly different between the two groups. However, vomiting was significantly more prevalent in the control group and hallucination was more common in the experimental group.
  
  
  CONCLUSIONS
  We conclude that administration of low doses of ketamine after spinal anesthesia reduces the need for analgesics and has fewer side effects than using opioids. Further studies are required to determine the proper dose of ketamine which offers maximum analgesic effect. Furthermore, administration of low-dose ketamine in combination with other medications in order to minimize its side effects warrants further investigation.
authors.affiliation: Department of Gynecology, Semnan University of Medical Sciences, Semnan, Iran.
authors.forename: Mojgan
authors.initials: M
authors.lastname: Rahmanian
authors.affiliation: Department of Gynecology, Semnan University of Medical Sciences, Semnan, Iran.
authors.forename: Mehri
authors.initials: M
authors.lastname: Leysi
authors.affiliation: Department of Anesthesiology, Semnan University of Medical Sciences, Semnan, Iran.
authors.forename: Ali Akbar
authors.initials: AA
authors.lastname: Hemmati
authors.affiliation: Research Center for Social Determinants of Health Community Medicine Department, Semnan University of Medical Sciences, Semnan, Iran.
authors.forename: Majid
authors.initials: M
authors.lastname: Mirmohammadkhani
keywords: Anesthesia, Spinal; Cesarean Section; Ketamine; Pain, Postoperative
references.citation: J Pain Palliat Care Pharmacother. 2002;16(3):27-35
references.pmid: 14640353
references.citation: Anesth Analg. 2005 Feb;100(2):475-80
references.pmid: 15673878
references.citation: Int J Obstet Anesth. 2011 Jan;20(1):3-9
references.pmid: 21224020
references.citation: Anaesthesia. 2000 Sep;55(9):899-904
references.pmid: 10947756
references.citation: Oman Med J. 2013 Jul;28(4):245-51
references.pmid: 23904916
references.citation: Int J Obstet Anesth. 2012 Jul;21(3):217-21
references.pmid: 22658477
references.citation: Can J Anaesth. 2001 Nov;48(10):1000-10
references.pmid: 11698320
references.citation: Acta Anaesthesiol Scand. 2001 Aug;45(7):795-804
references.pmid: 11472277
references.citation: Paediatr Anaesth. 2011 Jun;21(6):636-52
references.pmid: 21447047
references.citation: Eur J Anaesthesiol. 2005 Jul;22(7):518-23
references.pmid: 16045141
references.citation: Clin J Pain. 2010 Mar-Apr;26(3):223-6
references.pmid: 20173436
references.citation: Anesth Pain Med. 2013 Sep;3(2):230-3
references.pmid: 24282773
references.citation: Anesth Analg. 1997 Dec;85(6):1294-8
references.pmid: 9390597
references.citation: Anesth Analg. 2004 May;98(5):1385-400, table of contents
references.pmid: 15105220