MgSO4 supplementation: effect on hemodynamic to tracheal intubation, intra and postoperative analgesia in pre-eclamptic patients undergoing cesarean section

ABSTRACT

Magnesium is known to have an antinociceptive value, being a natural physiologic calcium antagonist, [N-Methy1-D-Aspartate] receptor antagonist, and also inhibits catecholamine release from the adrenergic nerve terminals. This study was performed to investigate the effect of m[g]so[4] on the stress response to laryngoscxopy, endotracheal intubation and surgery, as well as the postoperative analgesic repuriements and possible side effects to the fetus of the mother in forty parturients with moderate to sever pre-eclampsia undergoing cesarean section [c.s] under general anaesthesia. Parturients were divided into two group [each 20 patients]. The mg group received a bolus of m[g]so[4], 50mg/kg before intubation followed by infusion at a rate of 8 mg/kg/hour and for 6 hour postoperatively. The control-group received xylocaine bolus 1.5 mg/kg pre-intubation followed by infusion of equal volume of m[g] free acetated ringer solution for the same period. General anaesthesia induced by sodium thiopentone, m[g] or xylocaine bolus, succinly choline, orotracheal intubation, mechanical ventilation by isoflurane 0.5% and N2O O2 50%. Standard monitoring was used. Fentanyl [1-2 MICRO g/kg] was given after delivery of the baby as needed. Total intraoperative fentanyl was recorded as well as the total postoperative meperidine requirements. Maternal blood samples were collected, preoperative, after intubation, after delivery of the baby, early postoperative, 2 hour, 6 hours postoperatively for serum m[g] level. Cord blood was sampled for serum m[g] and fetal acid-base-status. Neonates were scored on the apgar system at 1 and 5 minutes. Postoperative pain and isomnia were assessed using visual analogue scales for 6 hours postoperatively as well as any possible maternal side effects [e.g, bleeding, vomiting, shivering]. Our results showed that the use of m[g]ao[4] was associated with better response to the stress of laryngoscopy and intubation as showed by the less significant changes in the means of heart rate and mean artrial pressure, and significant reduction of the total intra-and postoperative analgesic requirements, without any significant side effects on the number or the newborn. M[g]so[4] is a useful adjuvant to perioperative anesthetic management in pre-eclamptic parturients undergoing cesarean section under general anaesthesia