The effect of adjunct caudal block on postoperative analgesia in robot-assisted laparoscopic radical prostatectomy: A prospective randomized controlled, single blinded pilot study in a tertiary centre

Abstract

Objective: Caudal block provides satisfactory postoperative pain relief in lower abdominal operations. This pilot study explores its safety and effect on postoperative pain control in patients who underwent robot-assisted laparoscopic radical prostatectomy (RARP). Methods: From 2013 to 2014, 40 consecutive patients were randomized into two groups — one received caudal block using ropivacaine immediately after operation, the other received standard analgesia. Primary outcome measure was pain score based on 11-point Likert scale (0–10) recorded at recovery room, and at 6, 12, 24, 48, and 72 h after operation. All analgesic requirements, opioid-related adverse events and time to passage of flatus were examined. Results: Mean age of the two groups was similar (60.4 vs. 62.3 years, p = 0.33), as was American Society of Anaesthesiologists (ASA) class, body mass index (BMI) and operation times. No significant difference in median pain scores was reported in recovery room (2 vs. 3, p = 0.34), and at 6 h (2 vs. 2, p = 0.94), 12 h (0 vs. 0, p = 0.62), 24 h (1 vs. 0, p = 0.58), 48 h (1 vs. 0, p = 0.36) and 72 h (0 vs. 0, p = 0.78) postoperatively between control and caudal block groups, respectively. There was a higher mean opioid usage in the caudal block group which was not statistically significant. Although this was statistically insignificant while no significant difference in mean paracetamol usage was observed postoperatively. Median time to passage of flatus was similar (2.0 vs. 2.0 days, p = 0.97). There was one case of superficial wound infection and no opioid-related adverse events observed. Hospital stay was similar in both groups (2.5 vs. 2.5 days, p = 0.96). Conclusion: Although a safe modality, caudal block in post RARP patients does not seem to improve pain control nor reduce analgesia requirements. Keywords: Caudal block, Robotic radical prostatectomy, Post-operative pain, Analgesia, Opioid