The effect of magnesium sulphate on postoperative analgesia requirements in gynecological surgeries

Abstract

Objective:Recent studies have shown the positive effect of magnesium sulphate (MgSO4) on pain reduction and postoperative analgesic requirements in patients undergoing surgery. We assessed the effect of MgSO4 on intra-operative and postoperative analgesic requirements in patients undergoing lower abdominal gynecological laparotomy.Materials and Methods:This randomized clinical trial was conducted on 30 female patients at Rasool-e-Akram (referral and academic) hospital in Tehran from August 2012 to March 2013. The patients who were candidates for gynecologic surgeries (hysterectomy and/or myomectomy) were randomized into study (n=15) and control (n=15) groups. Same anesthetic technique was used in all patients. Besides induction of the anesthesia in the study group, we administered MgSO4 50 mg/kg/hr intravenously (IV) for analgesic purposes as a bolus dose and then 8 mg/kg IV as maintenance dose. Control group received the same anesthetic agents and the same amount of isotonic saline instead of MgSO4. Analgesic consumption was measured in both groups postoperatively within 24 hours. The visual analog scale (VAS) was used for the evaluation of postoperative pain in both groups.Results:There was a decrease in analgesic consumption and pain in the group receiving MgSO4, in comparison to control group. Pain severity assessment, 24 hours post operatively showed similar results in both groups. There was a statistically significant difference in prescribed dose of pethidine between study and control groups (p=<0.0001).Conclusion:Intra-operative MgSO4 is effective in postoperative pain control following lower abdominal laparotomy. Further studies with larger sample sizes and longer follow-up should be performed to obtain more information about safety and to determine whether doses of MgSO4 can provide postoperative analgesic benefits.

Comparison of intrathecal Tramadol and Magnesium sulfate as an adjuvant to Levobupivacaine in mild Pre-eclamptic parturients undergoing caesarean section A prospective randomized control study

“…Various studies of intrathecal magnesium also showed similar findings of extended duration of postoperative analgesia and decreased systemic analgesics requirements thereafter. 15,17,18,20,23,24 Our findings further support the role of magnesium sulfate, an NMDA antagonist, as an effective adjuvant for spinal anaesthesia. NMDA receptor activation leads to synaptic plasticity, wind-up phenomenon and central sensitization, which determines duration and intensity of postoperative pain.…”

“…5,[14][15][16][17][18] Magnesium sulfate via intrathecal route can be given in the doses like 50,75 and 100 mg. We have used Magnesium sulfate 100 mg intrathecally as it extends the postoperative analgesia, lessens the consumption of analgesics thereafter without increasing side effects. 5,17,[19][20][21] In our study, demographic data were comparable among the two groups. Onset of sensory block and time to achieve peak sensory level were late in Magnesium group in comparison to Tramadol group (p<0.0001).…”

“…Other authors had compared magnesium with fentanyl via intrathecal route and they found extended duration of motor block in magnesium group. 5,15,17,18,20 This may be because the half-life of fentanyl is less as compared to magnesium.…”

Efficacy of Prophylactic Mg Infusion for Reducing Shivering and Extend the Duration of Analgesia Caesarean Section with Spinal Anesthesia

“…Total intravenous anesthesia significantly reduced the need for magnesium, propofol, remifentanil and vecuronium in patients undergoing elective spinal surgery [29]. Tramer et al showed that magnesium sulphate infusion in patients undergoing abdominal hysterectomy under general anesthesia reduced PCA morphine consumption and improved sleeping comfort and comfort [35].…”

The Effect of a Preoperative Single Dose of Magnesium Sulfate versus Preoperative Ultrasound Guided Bilateral Transversus Abdominis Plane Block on Hemodynamics and Postoperative Analgesic Requirements in Patients Undergoing Colorectal Surgery

“…Asadollah et al [29] found that, preoperative and continuous infusion of magnesium sulfate was associated with significant decrease in pain score postoperatively with reduced the need to opioid analgesia in patients undergoing lower abdominal laparotomy.…”