Analgesic effects of caudal versus intravenous dexamethasone on bupivacaine based caudal block for paediatric infraumbilical surgeries

Abstract

Background: Singleshot caudal block provides short lived postoperative analgesia necessitating continued exploration for adjuvants. Aim was to compare the analgesic efficacy between intravenous and caudal dexamethasone on bupivacaine based caudal block for paediatric infraumbilical surgeries. Methods: Following ethical clearance and parental consent, 69 children aged 1-6 years, of American society of anesthesiologists (ASA) physical status classification I and II were randomized into groups A, B and C, of 23 each. All subjects underwent laryngeal mask airway (LMA) general anaesthesia induced with propofol and maintained with isoflurane in 100% oxygen, and had caudal block with 1 ml/kg bupivacaine 0.25%. Additionally, groups B and C received caudal 0.1mg/kg and intravenous preinduction 0.25 mg/kg dexamethasone, respectively. Pain was assessed using FLACC scale. The time to first analgesic request (TTFAR) was defined as the interval from caudal injection until pain score was ≥4; at this point, analgesic was given. Results: All 69 children were completely studied. The mean TTFAR (in minutes) was longest in Group B (485.40±24.50) followed by C (459.60±36.40), and shortest in group A (253.63±71.55), p=0.001, 0.024 and 0.968 for A versus B, A versus C and B versus C respectively, with greatest 24 hours pethidine consumption in Group A relative to groups B and C, p=0.001 and 0.025. Conclusions: Caudal 0.1 mg/kg or intravenous 0.25 mg/kg dexamethasone combined with bupivacaine significantly prolonged postoperative analgesic duration, with comparable analgesic profile between the caudal and intravenous routes, and without adverse effects.