title: Comparison of intrathecal magnesium, fentanyl, or placebo combined with bupivacaine 0.5% for parturients undergoing elective cesarean delivery.
abstract: BACKGROUND
  Intrathecal (i.t.) administration of magnesium has been reported to potentiate opioid antinociception in rats and humans. In this prospective, randomized, double-blind, study, we investigated the sensory, motor, and analgesic block characteristics of i.t. magnesium 50 mg compared with fentanyl 25 microg and saline when added to 0.5% bupivacaine (10 mg).
  
  
  METHODS
  Ninety ASA I or II adult patients undergoing cesarean section were randomly allocated to receive 1.0 ml of 0.9% sodium chloride in group S, 50 mg of magnesium sulfate (1.0 ml) 5% in group M, or 25 microg of fentanyl (1.0 ml) in group F following 10 mg of bupivacaine 0.5% i.t. We recorded the following: onset and duration of sensory and motor block, maximal sensory block height, the time to reach the maximal dermatomal level of sensory block, and the duration of spinal anesthesia.
  
  
  RESULTS
  Magnesium did not shorten the onset time of sensory and motor blockade or prolong the duration of spinal anesthesia. The duration of sensory (P<0.032) and motor (P<0.002) blockade was significantly shorter in M and S groups than in the F group. The time to reach the maximal dermatomal level of sensory block was significantly shorter in the F group than in the S and M groups (P<0.002).
  
  
  CONCLUSIONS
  In patients undergoing cesarean section with spinal anesthesia, the addition of magnesium sulfate (50 mg) i.t. to 10 mg of spinal bupivacaine (0.5%) did not shorten the onset time of sensory and motor blockade or prolong the duration of spinal anesthesia, as seen with fentanyl.
authors.affiliation: Department of Anesthesiology, Faculty of Medicine, Cukurova University, Adana, Turkey. unlugenc@cu.edu.tr
authors.forename: H
authors.initials: H
authors.lastname: Unlugenc
authors.forename: M
authors.initials: M
authors.lastname: Ozalevli
authors.forename: M
authors.initials: M
authors.lastname: Gunduz
authors.forename: S
authors.initials: S
authors.lastname: Gunasti
authors.forename: I F
authors.initials: IF
authors.lastname: Urunsak
authors.forename: T
authors.initials: T
authors.lastname: Guler
authors.forename: G
authors.initials: G
authors.lastname: Isik
mesh_terms: D000328:Adult; D002045:Bupivacaine / Q000008:administration & dosage* / Q000494:pharmacology*; D002585:Cesarean Section / Q000379:methods*; D004338:Drug Combinations; D005260:Female; D005283:Fentanyl / Q000008:administration & dosage* / Q000494:pharmacology*; D006801:Humans; D007278:Injections, Spinal; D008274:Magnesium / Q000008:administration & dosage* / Q000494:pharmacology*; D010146:Pain / Q000517:prevention & control; D010919:Placebos; D011247:Pregnancy
chemical_list: D004338:Drug Combinations; D010919:Placebos; D008274:Magnesium; D005283:Fentanyl; D002045:Bupivacaine