Comparison of Fentanyl and Dexmedetomidine as Additives to Caudal Levobupivacaine in Paediatric Patients Undergoing Infraumbilical Surgeries: A Randomised Clinical Trial

Introduction: In children, the most commonly used postoperative analgesic technique is epidural block via the caudal route. Levobupivacaine is an effective analgesic with a safer pharmacological profile. One of the primary drawbacks of a single-shot caudal block is its short duration of action. Fentanyl, although most commonly used opioid, it has many side-effects. Dexmedetomidine is an α2 agonist with the property of prolonging the analgesic effect of local anaesthetic. The effectiveness of fentanyl and dexmedetomidine as additives to caudal levobupivacaine has not been extensively studied; so, in the present investigation, the efficacy of aforementioned drugs was assessed in paediatric caudal analgesia using the Face, Legs, Activity, Cry, Consolability (FLACC) score. Aim: To compare the analgesic efficacy and safety of fentanyl and dexmedetomidine as adjuvants to caudal levobupivacaine in paediatric patients undergoing infraumbilical surgeries, using the FLACC score for postoperative pain assessment. Materials and Methods: This randomised, double-blind clinical trial was conducted at Shri BM Patil Medical College Hospital and Research Centre, BLDE DU, Bijapur, Karnataka, India, from December 2019 to August 2021 In this randomised clinical trial, caudal block was used to provide perioperative analgesia for children undergoing infraumbilical surgery. The children (n=46 per group) were randomly divided into two groups and given 0.75 mL/kg levobupivacaine 0.25% with dexmedetomidine 1 µg/kg and 0.75 mL/kg levobupivacaine 0.25% with fentanyl 1 µg/kg to group D (dexmedetomidine) and group F (fentanyl), respectively. Haemodynamic parameters, sedation score, sideeffects, FLACC score, and length of analgesia were all noted. Statistical analysis was performed using the Mann-Whitney U test, with a p-value <0.05 considered significant. Results: The two groups were comparable in terms of age, gender, weight, and duration of surgery. Both groups had stable comparable haemodynamic profiles, except at 20, 25, and 30 minutes post-block where MAP was higher in the fentanyl group. The mean Ramsay Sedation Score (RSS) was 2.1±0.3 (Group F) and 3.2±0.4 (Group D). The FLACC score was 3.79±0.47 (Group F) and 2.61±0.61 (Group D) at six hours. The mean duration of analgesia was 6.48±1.05 hours (Group F) and 8.76±1.06 hours (Group D). The mean discharge time was shorter in the dexmedetomidine group (3.13±1.22 days) compared to the fentanyl group (4.01±1.18 days). Conclusion: With similar haemodynamics and arousable sedation, dexmedetomidine is a more potent adjuvant to levobupivacaine for caudal analgesia than fentanyl. Dexmedetomidine is linked to shorter recovery time and fewer adverse effects following surgery.