Transrectal ultrasound-guided prostate biopsy: periprostatic block versus caudal block for analgesia-a randomized trial

Background: Transrectal ultrasound (TRUS)-guided prostate biopsy is a potentially painful procedure, due to the insertion of the TRUS probe in the anus and multiple passes of the biopsy needle through the rectum and prostate. Several methods of reducing pain and discomfort have been described. These include intra-rectal local anaesthetic gel (IRLA) instillation, periprostatic nerve block (PPNB), caudal block (CB) and oral analgesics. CB has potential complications of dural puncture and anaesthetic failure, while PPNB may be complicated by intravascular injection with systemic local anaesthetic toxicity. Only few studies have compared transrectal PPNB with CB with equivocal results. This study compared transrectal PPNB to CB in terms of efficacy of analgesia and incidence of complications. Methods: A prospective randomized clinical trial was carried out among 80 consenting patients with an indication for TRUS-guided prostate biopsy in the Urology division of [BLINDED FOR PEER REVIEW]. Eighty participants were each randomized to either of Group A (CB with 10 ml of 2% lidocaine) or Group B (PPNB with a total of 20 ml of 1% lidocaine). Pain was assessed using an 11-point numerical rating scale (NRS), and questions on satisfaction with the procedure and willingness for a repeat procedure were asked. The incidence of complications was also recorded. Results: There were no significant differences in the mean ages, body mass indices (BMIs), prostate-specific antigen (PSA) levels, digital rectal examination (DRE) findings and prostate sizes between the two groups. The mean NRS scores at administration of block, insertion of TRUS probe, prostate biopsy, 30 min and 1 day after biopsy were 2.9 +/- 2.3, 2.1 +/- 2.2, 3.1 +/- 2.6, 1.4 +/- 2.2 and 0.2 +/- 0.4 respectively for CB and 3.1 +/- 2.2, 2.3 +/- 1.2, 2.8 +/- 2.7, 1.4 +/- 1.7 and 0.3 +/- 0.5, respectively, for the PPNB group. There were no significant differences between the mean scores in both groups. There were also no statistically significant differences in the incidences of complications in both groups. Conclusion: The two methods of analgesia are similar in efficacy and are equally safe to employ in the performance of TRUS-guided prostate biopsy. Both methods can be learned to increase the repertoire of the urologist when faced with a TRUS-guided prostate biopsy.