Effects of intravenous lidocaine, dexmedetomidine and their combination on postoperative pain and bowel function recovery after abdominal hysterectomy

Abstract

Background: Intravenous (IV) lidocaine and dexmedetomidine have been shown to decrease postoperative pain, reduce analgesic consumption and facilitate return of bowel function. We investigated whether lidocaine combined with dexmedetomidine infusion was superior in controlling pain and recovery of bowel function.

Methods: A total of 240 women undergoing elective abdominal hysterectomy were randomly assigned into four groups: group CON received normal saline infusion, group LIDO received lidocaine infusion (1.5 mg/kg loading, 1.5 mg/kg/h infusion), group DEX received dexmedetomidine infusion (0.5 µg/kg loading, 0.4 µg/kg/h infusion) and group LIDO+DEX received lidocaine (1.5 mg/kg loading, 1.5 mg/kg/h infusion) and dexmedetomidine infusions (0.5 µg/kg loading, 0.4 µg/kg/h infusion). The primary outcome was visual analog pain scale (VAS) scores at 1, 4, 8, 12, 24, and 48 hours after surgery. The secondary outcomes included time to first bowel sounds and flatus, postoperative fentanyl requirement and perioperative propofol and remifentanil consumption.

Results: The VAS scores were significantly lower in groups LIDO and DEX at 4, 8, and 12 hours compared to group CON after surgery (P<0.01). The VAS scores were also significantly lower in group LIDO+DEX at 1, 4, 8, 12, and 24 hours compared to other three groups after surgery (P<0.01). Time to first bowel sounds and flatus was significantly shorter in groups LIDO and LIDO+DEX than groups CON and DEX (P<0.01). Postoperative fentanyl requirement was significantly lower in group LIDO at 1 and 4 hours and in group DEX at 1, 4, 8 hours compared to group CON after surgery (P<0.01). Postoperative fentanyl requirement was also significantly lower in group LIDO+DEX at 1, 4, 8, 12, 24 and 48 hours compared to other three groups after surgery (P<0.01). Propofol and remifentanil consumption was significantly lower in groups LIDO, DEX and LIDO+DEX compared to group CON (P<0.01).

Conclusions: Lidocaine combined with dexmedetomidine infusion significantly improved postoperative pain and enhanced recovery of bowel function undergoing abdominal hysterectomy.