A Randomized Controlled Trial for Prevention of Postspinal Anesthesia Shivering in Gynecological Surgeries: Mirtazapine vs. Dexamethasone

Abstract

Background. The frequency of shivering regarding regional anesthesia is 55%. Newer effective and tolerable options for postspinal anesthesia shivering (PSAS) prophylaxis are necessary to improve patients’ quality of care. This research assessed the impact of preemptive mirtazapine versus preemptive dexamethasone to decrease frequency and severity of PSAS in gynecological procedures. Methods. 300 patients booked for gynecological procedures under spinal anesthesia (SA) were randomly apportioned into three groups (100 each) to get one preemptive dose of 30 mg mirtazapine tablet (M group), 8 mg dexamethasone diluted in 100 ml of saline infusion (D group) or placebo (C group) two hours before surgery. Incidence of clinically significant PSAS was the primary outcome. Core temperature, shivering score, hemodynamics changes, adverse events, and patient satisfaction score were documented as secondary outcomes. Results. Compared with C group, mirtazapine and dexamethasone decreased incidence of clinically significant shivering (74% vs. 16% and 31%, respectively; P < 0.001 ). M and D groups had less hypotensive episodes during 5–25 min after intrathecal injection ( P < 0.001 ). 90 min after SA, tympanic temperatures were lower than baseline values in the three groups ( P < 0.001 ). Pruritus, nausea, and vomiting were more often in C group ( P < 0.001 ), whereas sedation was more frequent in M group ( P < 0.001 ). C group had the lowest satisfaction scores ( P < 0.001 ). Conclusion. Prophylactic administration of mirtazapine or dexamethasone attenuated shivering with minimal hazards in patients scheduled for gynecological surgeries under spinal anesthesia with priority to mirtazapine. The trial is registered with NCT03675555.

The Effect of Prophylactic Steroids on Shivering in Adults Undergoing Surgery: A Systematic Review and Meta-analysis of Randomized Controlled Trials

“…Twenty-five studies 7,14,15,26–47 were included in the final analysis (PRISMA flow chart; Figure 1). We excluded 1 study because there was a disparity between the results reported in the abstract and those reported in the main article.…”

“…7,14,15,26,29–31,33–43,45–47 However, a power analysis was reported in only 16 studies. 7,14,15,30,31,33–36,38,40,41,43,45–47 Dexamethasone was administered intravenously in 18 studies, 7,14,26,27,29,31,32,35,37–39,41–47 and through the intrathecal route in 3 studies. 28,36,40 Hydrocortisone was administered through the intravenous route in 4 studies.…”

“…48 Another study was excluded because the authors only evaluated the severity risk and not the risk of overall shivering. 49 While 2 studies evaluated the effect of prophylactic steroids on shivering in patients undergoing cardiac surgery, 7,27 19 studies were in patients undergoing various noncardiac surgeries, 15,26,[28][29][30][31][32][33][34][35][36][37][38][39][42][43][44][45][46] and 4 studies were performed in women undergoing cesarean deliveries. 14,40,41,47 Perioperative shivering was the primary outcome in 21 studies.…”

“…7,14,15,26,[29][30][31][33][34][35][36][37][38][39][40][41][42][43][45][46][47] However, a power analysis was reported in only 16 studies. 7,14,15,30,31,[33][34][35][36]38,40,41,43,[45][46][47] Dexamethasone was administered intravenously in 18 studies, 7,14,26,27,29,31,32,35,[37][38][39][41][42][43][44]…”

Evidence-Based Guideline on Prevention and Management of Shivering After Spinal Anesthesia in Resource-Limited Settings: Review Article

“…A RCT done by Ibrahim Esmat et al demonstrated that the use of dexamethasone reduces clinically significant shivering in patients undergoing gynecological surgery under spinal anesthesia decreased incidence of 16%. 31 Another study done by Abd el azeem et al showed that the use of dexamethasone is effective as pethidine in reducing incidence of shivering in patients undergoing TURP surgery under spinal anesthesia. The incidence of shivering was significantly high (P < 0.05) in the control group (15 patients, 50%) compared with the dexamethasone group (six patients, 20%) and the pethidine group (seven patients, 23%), with no statistically significant difference between the D and P groups.…”