Investigation of the Correlation of Block Success With Perfusion Index Measurement in Pediatric Surgery Performed Under Caudal Epidural Block Anesthesia"

A successful caudal epidural block can provide safe, effective regional anesthesia(4). The overall failure rate of caudal epidural block in pediatric patients is approximately 4% according to the anatomical and developmental abnormalities of the caudal canal(1,5). Therefore, reliable and rapid evaluation of a successful caudal epidural block is important to optimize anesthesia management in pediatric patients. Evaluating the success of the caudal epidural block with traditional methods such as mean arterial pressure(MAP), heart rate and cremaster reflex is completely objective.

The aim of this study is to evaluate whether it will detect the success of caudal epidural block faster than other traditional methods in pediatric patients who underwent surgery with caudal epidural block, using perfusion index values measured with a finger probe.

This research; It is a prospective observational study. In our pediatric patients who routinely underwent caudal epidural block under sedation in our hospital, perfusion index values will be recorded by attaching a probe to the big toe. Perfusion index(PI) is a numerical value for the ratio between pulsatile and non-pulsatile blood flow.(6) PI works by measuring the changes in finger peripheral perfusion through pulse oximetry.(7) If the procedure is successful in patients who underwent caudal epidural block, there is an increase in perfusion in the lower extremities due to sympathetic nerve blockade. Therefore, in our study, we will observe whether perfusion increases by measuring the perfusion index value measured using a finger probe, by attaching the probe to the big toe, before the caudal epidural block is performed and at the 1,5, 7, 10, 15 and 20 minutes after the caudal epidural block. Simultaneously, the mean arterial pressure, heart rate and changes will be recorded by looking at the cremaster reflex in male patients. The finding that shows the presence of the cremaster reflex is to hit the upper inner part of the thigh and to pull the scrotum and testis on the same side. A 15% decrease in pulse rate and an increase in the perfusion index value indicate a successful caudal epidural block. We will examine whether the increase in the perfusion index after these procedures is correlated with the success of the block, and whether the perfusion index shows a faster block success than other traditional methods.