Background and aims: Caudal epidural block is a commonly used technique for perineal surgeries in children. It is also used for chronic pain management in adults. Due to anatomical changes and variation, failure rate of caudal block in adults is very high with conventional landmark guided technique even in experienced hands. With the advent of ultrasonography, the success rate of caudal block has improved leading to resurgence of interest. This study aims to find effectiveness of USG guided caudal block for post-operative analgesia in adult perineal surgeries. It also compares Ropivacaine 20 ml of 0.25% versus Dexamethasone 8 mg added as an adjuvant to Ropivacaine in terms of the duration of post-operative analgesia, patient satisfaction and any side effects.

Methods: In a randomized and double blind study, 60 patients scheduled for Perineal surgery under spinal anesthesia were randomly divided into two equal groups, Group R (n=30) and Group D (n= 30). Out of 60 patients enrolled, two patients were excluded and 58 patients were analyzed. After surgery, ultra-sound guided caudal block with Ropivacaine 0.25% 20 ml was given in group R and Ropivacaine 0.25% 20 ml and 8 mg Dexamethasone was given in group D in each patient. The NRS at 4, 6, 8, 10,12,14,16,18, 20, 22, and 24 hours after the caudal block was noted. The primary objective was to find the duration of post-operative analgesia (first request to rescue analgesia) and compare the two groups. The secondary objectives were to compare total amount of tramadol consumption between the two groups in 24 hours, to compare the pain scores (NRS) and patient satisfaction.

Results: Duration of post-operative analgesia i.e. time to first analgesic request was 15.24 ± 4.57 h in Group R compared to 17.72 ± 4.71 h in Group D. This result was statistically significant (p=0.04). The total tramadol consumption over 24 hours was comparable in group R and group D (p = 0.08). Pain scores (NRS) were comparable in group R and group D at all-time points of 4h, 6h, 8h,10h,12h,14h, 16h,18h, 20h, 22h, and 24h (p>0.05). Patient satisfaction in both groups was comparable (p=0.41). No patient had any block related complication.

Conclusion: The study concludes that USG guided caudal block is an effective mode of post-operative analgesia in adult perineal surgeries. Adding Dexamethasone to Ropivacaine increases the duration of post-operative analgesia compared to Ropivacaine. The total amount of tramadol consumption, pain scores and patient satisfaction were comparable between the two groups. Hence USG guided caudal block can be incorporated in multimodal analgesia for adult perineal surgeries.

Adult Caudal block, Post-operative analgesia, Perineal surgeries