Introduction: Numerous methods have been employed for post-herniotomy analgesia with caudal block being the technique of choice. The study compared the analgesic efficacy of caudal block with a combination of intravenous ketorolac and paracetamol on the duration of post-herniotomy analgesia. 

Materials & Methods: Eighty-eight ASA I or II patients aged 1 to 8 years were randomized equally into group C (caudal 0.75ml/kg of 0.25% bupivacaine) and group KP (intravenous 1mg/kg ketorolac plus 15mg/kg paracetamol). Study drugs were administered after induction of anaesthesia but prior to skin incision and no other analgesic was given intraoperatively. Postoperative pain was assessed using the Objective Pain Scale (OPS) at 0min, 15min, 30min, 45min, 60min, 2hour, 4hour, 6hour, 12hour and 24hour. 

Results: All the 88 patients were pain-free at 45 minutes. At 2 hours, 40 and 30 patients were pain-free in groups C and KP respectively (p = 0.012) while the median pain scores were comparably low in both groups (OPS = 3; p=0.27). At 4 hours, 23 and 7 patients were pain-free in groups C and KP respectively; p = 0.007. The OPS scores at 4 hours in group C were 4 (2-4) in preverbal and 3 (1-4) in verbal children while in group KP the scores were 1 (0-2) in preverbal and 1 (1-3) in verbal children; p < 0.001. At 6 hours, all remaining patients in both groups had received rescue analgesic. The time to first analgesic request was 291.93±68.01 minutes and 223.23±70.86 minutes in groups C and KP respectively (p < 0.001, C.I = 39.27, 98.14). Group C patients received postoperative pentazocine more frequently (1.61±0.49) than 1.27±0.45 in group KP; p=0.001. Parental satisfaction was significantly higher in group KP (86.4%) than 68.2% in group C; p=0.08. 

Conclusion: Caudal bupivacaine significantly prolonged the time to first analgesic request more than intravenous ketorolac plus paracetamol. Intravenous ketorolac plus paracetamol, however, significantly reduced the frequency of postoperative pentazocine request and conferred higher parental satisfaction.