Intrathecal injection of magnesium sulfate: shivering prevention during cesarean section: a randomized, double-blinded, controlled study.
BACKGROUND
Regional anesthesia is known to significantly impair thermoregulation and predispose patients to hypothermia. We hypothesized that the addition of an intrathecal injection of magnesium sulfate (MgSO4) to bupivacaine would improve perioperative shivering in female patients undergoing elective caesarean section.


METHODS
In a block-randomized, double-blinded, controlled trial 72 patients scheduled for elective caesarean section with spinal anesthesia were separated into two groups. In the treatment group, 2 ml of 0.5% bupivacaine plus 25 mg MgSO4 (0.5 ml) were injected intrathecally, and in the control group 2 ml of 0.5% bupivacaine plus 0.5 ml normal saline were injected intrathecally. Core temperature was measured before and after drug injection at predetermined intervals. Sedation was graded using the Ramsay sedation scale.


RESULTS
No significant intergroup differences in appearance of shivering were seen immediately or at 5, 30, 40, 50, 60, and 90 min after block administration. However, at 10, 15, and 20 min post block, there was a significant difference in shivering. The group administered MgSO4 showed lower shivering grades compared with the control group. Core temperature was significantly reduced in the MgSO4 group compared to the normal saline group 30 min after blocking.


CONCLUSIONS
Intrathecal injection of MgSO4 improved perioperative shivering in female patients undergoing elective caesarean section.
Department of Anesthesiology and Pain Medicine, Rasoul-Akram Medical Center, Tehran University of Medical Sciences, Tehran, Iran.
Seyed Hamid Reza
SH
Faiz
Poupak
P
Rahimzadeh
Farnad
F
Imani
Ali
A
Bakhtiari
Bupivacaine; Cesarean section; Magnesium sulfate; Shivering