Rectal puncture complicating caudal blockade in a child with severe rectal distension

A randomized double-blinded controlled trial comparing ultrasound-guided versus conventional injection for caudal block in children undergoing infra-umbilical surgeries

Background and Aims:

Caudal epidural block is widely used in pediatric surgeries to provide intraoperative and postoperative analgesia in infra-umbilical surgeries. The conventional technique involves the risk of multiple punctures and other complications such as dural puncture, vascular puncture, and intraosseous injection.

Material and Methods:

Around 106 children aged between 6 months to 10 years belonging to ASA class I-II scheduled for elective infra-umbilical surgeries were included after obtaining written informed consent from parents/guardians. All children were randomized into two groups: ultrasound-guided (Group U) or conventional caudal group (Group C). All were premedicated with oral midazolam and inhalational induction was done with oxygen and 6–8% sevoflurane. Caudal block of 1 mL/kg of 0.125% bupivacaine was administered in both groups. The primary outcome assessed was 1^st puncture success rate and the secondary outcomes assessed were number of skin punctures, block performing time, and block success rate.

Results:

Group U had a higher first puncture success rate (P = 0.001) than Group C (90.6% v/s 64.2%) and was statistically significant. The number of punctures were significantly less (P = 0.01) in Group U (1.09 ± 0.295) than Group C (1.45 ± 0.667). Block performing time was significantly higher (P = 0.0005) in Group U (53.19 ± 10.97 s) than Group C (30.34 ± 7.34 s). There was no difference in the overall block success rate between the groups (98.1% v/s 100%).

Conclusion:

Ultrasound-guided caudal injection increases the first puncture success rate and decreases the number of punctures required compared to conventional caudal block in pediatric infra-umbilical surgeries.

Risk of rectal puncture due to needle entry into the presacral space: Importance of measuring the distance between the rectum and sacrococcyx, and the thickness of the sacrococcyx

During ganglion impar block, the needle may approach the presacral space and the sacrum may be penetrated during caudal anesthesia. Because the rectum is in front of the sacrococcyx and is thus at risk for puncture, it is important to determine the distance between the sacrococcyx and rectum, as well as the thickness of the sacrococcyx.Computed tomography was used to measure the distance between the rectum and sacrococcyx, as well as the thickness of the sacrococcyx. The distances between the coccyx and rectum, sacrococcygeal joint and rectum, sacral level 5 ('sacrum 5') and rectum, and 'sacrum 4 to 5 junction' and rectum were measured. The results were compared based on the presence or absence of stools in the rectum. The thickness of the sacrococcyx was measured at the sacrum 4 to 5 junction and sacrococcygeal joint.In total, 1264 patients were included in this study. All distances were less than 1 mm in both males and females, with the exception of the distance between the coccyx and rectum in males. In both males and females, there was no significant difference in distance between the sacrococcyx and rectum according to the presence or absence of feces in the rectum, but there was a difference in the distance between sacrum 5 and the rectum in males (P = .048). Several male and female patients showed thicknesses of less than 5 mm at the sacrococcygeal joint.Some patients have a distance of less than 1 mm between the sacrum and rectum. Practitioners should exercise caution when applying a needle to the presacral space. If the sacrum is accidentally penetrated during caudal block, rectum puncture cannot be ruled out. Excretion of feces does not influence the distance between the sacrococcyx and rectum in females.

Caudal Epidural Block: An Updated Review of Anatomy and Techniques

Caudal epidural block is a commonly used technique for surgical anesthesia in children and chronic pain management in adults. It is performed by inserting a needle through the sacral hiatus to gain entrance into the sacral epidural space. Using conventional blind technique, the failure rate of caudal epidural block in adults is high even in experienced hands. This high failure rate could be attributed to anatomic variations that make locating sacral hiatus difficult. With the advent of fluoroscopy and ultrasound in guiding needle placement, the success rate of caudal epidural block has been markedly improved. Although fluoroscopy is still considered the gold standard when performing caudal epidural injection, ultrasonography has been demonstrated to be highly effective in accurately guiding the needle entering the caudal epidural space and produce comparative treatment outcome as fluoroscopy. Except intravascular and intrathecal injection, ultrasonography could be as effective as fluoroscopy in preventing complications during caudal epidural injection. The relevant anatomy and techniques in performing the caudal epidural block will be briefly reviewed in this article.