Ultrasound guided pediatric caudal dose: a two-center randomized controlled trial.

Background: The drug volume to be used in caudal in pediatric patients has remained an unmet issue since long. We determined the minimum drug volume required to reach T10 level in pediatric patients using ultrasonography and compared it with the already established volume by Armitage formula.

Aim: To determine the minimum effective caudal local anesthetic dose using ultrasound guidance.

Methods: Study was performed at two centres and at each centre, 50 pediatric patients (Total 100 patients), aged 1 to 3 years, undergoing below umbilical surgeries were included and randomised into two groups of 25 each (Total 50) to receive ultrasound guided drug volume vs. Armitage formula based volume. The volume required to reach T10 level was assessed with ultrasound in one group. Also, maximum height achieved, cutaneous level achieved after 15 min, FLACC scores 30 min post extubation and parental satisfaction scores were noted.

Results: The mean drug volume required to reach T10 level in Group U was 0.755 ± 0.053 ml/kg with a P value < 0.001. (Compared to the drug volume of 1 ml/kg using one sample t test). The highest level achieved in both groups were calculated as the mode value of T8 and T7 in Group U and Group A respectively. The highest cutaneous level achieved after 15 min was also calculated as the mode value of T4 in both groups. FLACC scores at 30 min were also comparable. Satisfaction scores were comparable in both groups.

Conclusion: A volume of 0.7 ml/kg of local anaesthetic in pediatric caudal block is sufficient to achieve a target of T10 level for infraumblical surgeries.