effect of intrathecal magnesium sulphate versus intra venous magnesium sulphate on spinal fentanyl analgesia

This double-blinded, comparative study was designed to compare between the analgesic efficacy and safety of adding magnesium sulphate [MgSO4] intrathecal [I.T] versus intravenous [IV] MgSO4 on spinal fentanyl analgesia [1micro g / kg]. sixty pediatric patients of 6-12 years undergoing surgeries on the lower half of the body eg :inguinal hernia, hypospadius, undescended testis under sevoflurane: nitrous oxide anaesthesia were included. No intra-operative narcotics were administered. Patients were allocated into 3 groups [20 patients each] G[fit] received IT fentanyl micro/kg, G[mgit] received IT fentanyl 1mg /kg plus IT MgSO4 1mg/kg, G[mgiv] received IT fentanyl 1 micro g /kg plus IVMgSO4 20mg/kg as a loading dose, followed by infusion at a rate of 10mg /kg /h. Pain was evaluated by visual analogue pain scale [VAPS]. Duration of post operative analgesia was defined as the interval between intrathecal analgesic mixture administration and the first patient's request for additional analgesia. there was a significant prolongation of the duration of analgesia in group G[mgit] and group G[mgit] compared with group G[fit]. Also there was a significant decrease in VAS in group G[mgit] compared with G[fit]. No differences were noted among groups as regards haemodynamic and Ramsay sedation score. The addition of MgSO4 either intratheeaily or intravenously proiongd the spinal opioid Analgesia in humans and it is safe even in high doses. So the MgSO4 could be of clinical importance for pain management