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.
Anesthesia, Conduction ; Anesthesia, Spinal ; Body Temperature Regulation ; Bupivacaine ; Cesarean Section* ; Female ; Humans ; Hypothermia ; Injections, Spinal* ; Magnesium Sulfate* ; Pregnancy ; Shivering*

bjective: To determine the values of amniotic fluid (AF) progesterone and biochemical constituents and its associated placenta traits in Iranian crossbred ewes (Arkhar-Merino×Ghezel). Methods: Sixty ewes (2-5 years old, weighing 40-50 kg) were treated with controlled internal drug release induced 30 mg progesterone for 14 d and were injected with 400 IU pregnant mare serum gonadotropin at the time of CIDR withdrawal. After the detection of estrus, ewes were hand-mated. After expelling of each fetus accompanied by fetal membranes, 10 mL AF was taken from fetal sac for spectrophotometer methods (glucose, urea, creatinine, total protein, cholesterol, triglycerides, calcium and phosphorus) and radioimmunoassay (progesterone) analysis. Results: Results indicated that there were highly positive correlations between placental efficiency and cotyledon density (r=0.764, P<0.01), and negative correlation between placental weight (PW) with the total volume amniotic fluid (TVAF) (r=-0.872, P<0.01). A positive relationship was calculated between TVAF with total protein and creatinine (r=0.418, P<0.01 and r=0.639, P<0.05, respectively). However, the correlation between the glucose and PW, cotyledon length and calcium were significantly positive (r=0.704 and r=0.712; P<0.01, respectively). The findings of this study demonstrated that there were no relationships between progesterone concentrations and placental traits (P>0.01), except for PW (r=0.665). Conclusions: In conclusion, the significant correlation between the AF biochemical and progesterone with placental traits for the above-mentioned metabolites suggests that metabolic changes in AF levels will reflect the condition in the AF.