Ultrasound assessment of cranial spread during caudal blockade in children: Effect of different volumes of local anesthetic.

BACKGROUND

Ultrasound-guided caudal block injection is a simple, safe, and effective method of anesthesia/analgesia in pediatric patients. The volume of caudal drug required has always been a matter of debate.

MATERIALS AND METHODS

This present prospective, randomized, double-blinded study aimed to measure extent of the cranial spread of caudally administered levobupivacaine in Indian children by means of real-time ultrasonography. Ninety American Society of Anesthesiologists I/II children scheduled for urogenital surgeries were enrolled in this trial. Anesthesia and caudal analgesia were administered in a standardized manner in the patients. The patients received 0.5 ml/kg or 1 ml/kg or 1.25 ml/kg of 0.125% levobupivacaine according to the group allocated. Cranial spread of local anesthetic was noted using ultrasound.

RESULTS

There was no difference in the spread when related to age, sex, weight, or body mass index. A significant difference of ultrasound-assessed cranial spread of the local anesthetic was found between Group 1 (0.5 ml/kg) with both Group 2 (1 ml/kg) ( = 0.001) and with Group 3 (1.125 ml/kg) ( < 0.001) but there is no significant difference between Group 2 and Group 3 ( = 0.451) revealing that spinal level spread is only different between 0.5 ml/kg and 1 ml/kg of local anesthetic.

CONCLUSION

In conclusion, the ultrasound assessment of local anesthetic spread after a caudal block showed that cranial spread of the block is dependent on the volume injected into the caudal space. Since there was no difference between 1 ml/kg and 1.25 ml/kg, to achieve a dermatomal blockade up to thoracic level, we might have to increase the dose beyond 1.25 ml/kg, keeping the toxic dose in mind.