Comparison of analgesic efficacy of bupivacaine, bupivacaine with dexmedetomidine, and bupivacaine with fentanyl in local perianal infiltration technique in perianal surgeries: A prospective, randomized controlled study

Abstract

Background: Numerous methods have been proposed to alleviate pain after perianal surgeries but the role of addition of Dexmedetomidine or fentanyl to bupivacaine as local infiltration in surgical wound for post-operative analgesic effect is less explored. Hence a study was conducted to compare the efficacy of wound infiltration with bupivacaine, bupivacaine with fentanyl and bupivacaine with Dexmedetomidine for post-operative analgesia following perianal surgeries. Methods: 75 patients with ASA physical status of I and II scheduled for perianal surgeries were recruited for the study. The patients were randomly assigned into 3 groups namely DM, F and C. Group DM received perianal wound infiltration with 0.5% bupivacaine 15ml which included Dexmedetomidine 1.5 µg /kg, Group F received perianal wound infiltration with 0.5% bupivacaine 15 ml which included Fentanyl 2µg/ml and Group C received perianal wound infiltration with 0.5% bupivacaine 15 ml which included 1 ml saline. Post-operative quality of analgesia was assessed by VAS (0-10) for 24 h and rescue analgesic was administered when VAS > 4. Pain score at the time of defecation was also noted. Total dose of analgesic needed in 24 hours and side effects were noted. Results: Group DM had significantly longer duration of postoperative analgesia when compared with Group F and group C. Group F had prolonged postoperative analgesia when compared to Group C. The pain score at first defecation was significantly lower in Group DM when compared to both Group F and Group C. None of the patients developed skin rash, respiratory depression, hypotension, hypoxemia, and there were no significant tachycardia or bradycardia. Conclusions: Perianal wound infiltration with Dexmedetomidine-bupivacaine mixture provides prolonged analgesia, and decreases the total analgesic consumption in patients undergoing perianal surgeries.