Does magnesium sulfate reduce the short- and long-term requirements for pain relief after caesarean delivery? A double-blind placebo-controlled trial.
OBJECTIVE
The purpose of this study was to determine whether magnesium sulfate decreases postoperative pain and analgesic consumption.


METHODS
Women who underwent elective cesarean delivery were randomized into groups according to high-dose magnesium sulfate (50 mg/kg load and 2 g/h), low-dose magnesium sulfate (25 mg/kg load and 1 g/h), or placebo. Before the delivery, the dose of patient-controlled opioid that was used and the visual analogs of pain during the first 48 hours after delivery and at 6 weeks were assessed.


RESULTS
Forty-two women were assigned randomly to the high-dose arm; 38 women were assigned to the low-dose magnesium arms, and 40 women were assigned to the control arm. The cumulative opioid use (P = .636); pain scores at 6, 12, 24, and 48 hours at rest (P = .786) and with movement (P = .179); the use of analgesics after hospital discharge (P = .711); and wound pain with movement (P = .429) or pressure (P = .144) after 6 weeks were similar.


CONCLUSIONS
Magnesium sulfate does not reduce the severity of short-term or long-term (6 weeks) pain after cesarean delivery.
Paech
Michael J
MJ
Department of Anesthesiology, King Edward Memorial Hospital, The University of Western Australia, Perth, Australia.
Magann
Everett F
EF
Doherty
Dorota A
DA
Verity
Lisa J
LJ
Newnham
John P
JP
D000328:Adult; D000700:Analgesics / Q000008:administration & dosage / Q000627:therapeutic use*; D000701:Analgesics, Opioid / Q000008:administration & dosage / Q000627:therapeutic use; D002585:Cesarean Section; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D008278:Magnesium Sulfate / Q000008:administration & dosage / Q000627:therapeutic use*; D010147:Pain Measurement; D010149:Postoperative Pain / Q000503:physiopathology / Q000628:therapy*; D010166:Palliative Care; D013997:Time Factors; D017211:Treatment Failure
D000700:Analgesics; D000701:Analgesics, Opioid; D008278:Magnesium Sulfate