Assessment of Cranial Spread of Two Different Volumes of Local Anesthetics Using Ultrasound during Caudal Blockade in Children.

Abstract

Background and aims: Single-shot caudal anesthesia is the most commonly used regional anesthesia technique in children with broad spectrum of indications. Although several studies have been in relation to caudal anesthesia the issue of volume of local anesthetics and its cranial spread has always been a matter of debate with discrepancies noted between clinical assessment and radiographic spread of the drug. The aim of the present study was to evaluate the cranial spread of two volumes of caudally administered local anesthetics in pediatric patients by means of real-time ultrasound.

Materials and methods: Fifty children of 1-6 years of age belonging to American Society of Anesthesiologists status I/II scheduled for infraumbilical surgeries were administered general anesthesia followed by ultrasound guided caudal anesthesia with 0.25% levobupivacaine, either 1 ml/kg or 0.75 ml/kg with 25 children in each group. Real-time placement of the drug and its maximum cranial spread with respect to T12 vertebrae was noted using ultrasound. Hemodynamic parameters on surgical incision was noted among the groups. Frequencies are presented with descriptive statistics and t-test is used to study difference between the two groups.

Results: It was noted that the group receiving 0.75 ml/kg of drug had the drug spread between the L2 and L3 vertebral level and the group receiving 1 ml/kg had spread between L1 and L2. There was a positive correlation between dose of drug and distance from T12 vertebra with 1 ml/kg of the drug having a mean of 3.25 ± 1.07 cm whereas 0.75 ml/kg had a mean of 4.44 ± 0.87 cm (P = 0.0001). Patient demographics and hemodynamic parameters on incision were comparable among the groups.

Conclusion: This study showed that there was a positive correlation between volume of local anesthetic injected in caudal space and its cranial spread with respect to distance from T12 however on comparison between vertebral levels the maximum deposition of local anesthetic was between L1 and L2 for 1 ml/kg and between L2 and L3 for 0.75 ml/kg, respectively.