Archives of Critical Care Medicine

Background: Effective pain relief is very important for parturient women because they are expected to recover expeditiously and to care for their newborns within a few hours following surgery. Recent studies have identified N-methyl-D aspartate (NMDA) receptors peripherally and their major role in nociceptive transmission. Magnesium has an antagonistic effect on NMDA receptors.
Objectives: The aim of the present study was to evaluate the analgesic effect of intra-incisional Mg on women undergoing elective
cesarean section.
Patients and Methods: In this blinded clinical trial, 192 patients undergoing elective cesarean section were randomly divided into two groups; intervention (n = 96, 20 mL of 750 mg magnesium sulfate diluted in normal saline) and control (n = 96, 20 mL normal saline) groups. Intra-incisional injection was applied before wound closure. Postoperative pain based on visual analogue scale (VAS) score and cumulative rescue analgesia in the first 24 hours was recorded and compared between the groups.
Results: The mean age of participants was 27.91 ± 5.19 years old. The mean duration of surgery was 41.05 ± 7.87 minutes. The mean of VAS score in the magnesium sulfate group was significantly lower than the control group in all the evaluations. The means of cumulative diclofenac requirement in the case and control groups were 146.57 ± 92.89 and 205.7 ± 108.43 mg, respectively, which in the case group was significantly less than the control group (P = 0.000, CI 95% = 64.23-54.04)
Conclusions: According to the result of the present study, it seems that incisional injection of magnesium sulfate in post-cesarean section pain management is safe and useful. Further studies are required to evaluate other doses as well as toxicity in longer durations than the first postoperative da