A comparative evaluation of dexamethasone and MgSO4 as an adjuvant to ropivacaine in transversus abdominis plane block for post operative analgesia in patients undergoing elective cesarean section, a triple blinded randomised controlled trial

Abstract

: In regional blocks, dexamethasone and magnesium sulphate (MgSO4) have been used as an adjunct to local anesthesia. But more research needs to be done on each one's effectiveness. This study aims to assess the efficacy of dexamethasone 4mg and MgSO4 150mg as an adjunct to ropivacaine 0.375% in transversus abdominis plane (TAP) block for postoperative analgesia in patients undergoing cesarean section under subarachnoid block (SAB).: Ninety patients undergoing cesarean section under SAB belonging to American Society of Anesthesiologists physical status I or II, were recruited and randomised in three groups. Each group comprised of 30 patients. Group RS received 20ml 0.375% ropivacaine with 2 ml normal saline, Group RD received 20ml 0.375% ropivacaine with 4 mg dexamethasone and Group RM received 20ml 0.375% ropivacaine with 150 mg MgSO4.Time to first analgesic request, VAS score at rest and movement, patient satisfaction score, hemodynamic parameters and side effects were recorded in each group post-TAP block for 24 hours. Time to first analgesic request was significantly longer in group RD (814.0± 277.3 min) compared to group RM (606.5 ± 279.9 min) and group RS (545.5 ± 254.3 min) (p = 0.001). The mean value of tramadol requirement was statistically higher in Group RS compared to Group RD and Group RM (p<0.001). The mean differences in VAS score at rest and movement at 6 & 8 h was significantly lower in dexamethasone and MgSO4 compared to control group p=0.001. The addition of dexamethasone to ropivacaine in TAP block significantly prolonged the duration of analgesia, reducing the need for systemic analgesia with minimal side effects.