Effects of Preemptive Analgesia by Caudal Route using Spinal Column Height Based Formula for Dose Calculation in Paediatric Patients Undergoing Infra Umbilical Surgery

Background: Caudal analgesia is a widely used technique for providing perioperative pain relief in pediatric patients undergoing infraumbilical surgeries. However, determining the appropriate dosage of local anesthetic agents can be challenging due to variations in pediatric anatomy and body habitus. Various formulae have been used for dose calculation based on body weight, spinal column height, age of patient, rate of injection etc. It is not possible to address all these factors while constructing these formulae. This study aims to explore that use of spinal column height-based formulae for dose calculation aiming to optimize analgesia while minimizing the risk of adverse effects other than body weight-based formulae.Methods: This Quasi experimental study was carried out between June 2022 to November 2023 at Dhaka Medical College and Hospital. 50 patients belonging to ASA I and II of either sexes (25 patients in each group) were randomly allocated into two groups equally; Group A (Study group) received 0.25% plain bupivacaine according to spinal column height based modified Spiegel formulae and Group B (Control group) received 0.25% plain bupivacaine according to body weight based Armitage formulae. Drug volume was calculated according to respective formulae in both groups. Respiratory rate, Oxygen saturation and haemodynamic parameters (HR, MAP) were recorded at different time level. In the Post Anaesthesia Care Unit (PACU), level of sensory block and pain intensity were assessed by pin prick method and Wong Baker FACES pain scores respectively, at 5, 10, 15, 20, 30, 60 and 120 minutes then hourly upto 6 hours. Level of motor block was also assessed by modified Bromage scale during this period.Results: The mean number of spinal segments blocked was significantly different among groups (p< 0.001) with patients in group A (4.11±0.22) showing significantly lower number of spinal segments blocked as compared to that in group B (4.40±0.21; p< 0.001). The mean volume of 0.25% bupivacaine used in group A was significantly lower (p< 0.001) than that in group B.Conclusion: Caudal analgesia utilizing a spinal column height-based formula for dose calculation offers a reliable and precise approach for pain management in pediatric patients undergoing infraumbilical surgery while minimizing the risk of adverse events.