title: Antishivering effects of two different doses of intrathecal meperidine in caesarean section: a prospective randomised blinded study.
abstract: OBJECTIVE
  Shivering causes various adverse disturbances and interferes with monitoring. The optimal dose of intrathecal meperidine to prevent shivering without producing other side-effects remains unknown. This prospective randomised double-blinded study was conducted to compare the antishivering effects of two different doses of intrathecal meperidine.
  
  
  METHODS
  Seventy two parturients, scheduled for elective caesarean section under spinal anaesthesia, were enrolled in three different groups. Spinal anaesthesia consisted of bupivacaine 0.5% (10 mg) for the control group (M0), and the same dose of bupivacaine with meperidine 12.5 or 25 mg for the experimental groups (M1, M2). Blood pressure, heart rate, skin and core temperatures, sensory level, capnometry, pulse oximetry, Apgar scores, shivering intensity and intrathecal opioid-related side-effects were evaluated and recorded by a blinded observer. Data were analysed using analysis of variance, χ² test, Kruskal-Wallis H-test and Mann-Whitney U-test. A P value less than 0.05 was considered to be significant.
  
  
  RESULTS
  Shivering was more intense in group M0 than in groups M1 and M2 with P values of 0.003 and less than 0.001, respectively. The intensity of shivering was comparable in groups M1 and M2. As regards the incidence of significant shivering, it was found to be highest in M0 (4/24 ≈16.7%) in comparison with M1 (0/24) and M2 (0/24) (P = 0.03). Nausea and vomiting occurred more frequently with higher doses of meperidine (P < 0.001 and P = 0.003, respectively). Other complications were comparable.
  
  
  CONCLUSIONS
  The use of intrathecal meperidine for caesarean section during spinal anaesthesia for the prevention of shivering cannot be recommended as its use is associated with increased incidence of nausea and vomiting.
authors.affiliation: Department of Anesthesiology, Tehran University of Medical Science, Imam Khomeini Medical Center, Keshavarz Blvd., Tehran 1419733141, Iran. khanzh51@yahoo.com
authors.forename: Zahid H
authors.initials: ZH
authors.lastname: Khan
authors.forename: Amir P
authors.initials: AP
authors.lastname: Zanjani
authors.forename: Jalil
authors.initials: J
authors.lastname: Makarem
authors.forename: Shahram
authors.initials: S
authors.lastname: Samadi
mesh_terms: D000293:Adolescent; D000328:Adult; D000701:Analgesics, Opioid / Q000008:administration & dosage / Q000009:adverse effects / Q000494:pharmacology*; D000773:Anesthesia, Obstetrical / Q000379:methods; D000775:Anesthesia, Spinal / Q000379:methods; D000779:Anesthetics, Local / Q000008:administration & dosage; D002045:Bupivacaine / Q000008:administration & dosage; D002585:Cesarean Section / Q000379:methods; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007278:Injections, Spinal; D008614:Meperidine / Q000008:administration & dosage / Q000009:adverse effects / Q000494:pharmacology*; D009325:Nausea / Q000139:chemically induced / Q000453:epidemiology; D011247:Pregnancy; D011446:Prospective Studies; D012768:Shivering / Q000187:drug effects*; D014839:Vomiting / Q000139:chemically induced / Q000453:epidemiology; D055815:Young Adult
chemical_list: D000701:Analgesics, Opioid; D000779:Anesthetics, Local; D008614:Meperidine; D002045:Bupivacaine