A review of the surface and internal anatomy of the caudal canal in children

Ultrasound-guided trans-incisional quadratus lumborum block versus ultrasound-guided caudal analgesia in pediatric open renal surgery: a randomized trial

BACKGROUND

The caudal route is a common approach for postoperative analgesia; however, it is associated with limited duration of action. The quadratus lumborum block (QLB) may produce prolonged postoperative analgesia. Therefore, this study aimed to compare the postoperative analgesic efficacy of the ultrasound-guided caudal block with that of the ultrasound-guided transincisional QLB (TiQLB) in pediatric patients undergoing open renal surgery.

METHODS

Forty patients of both sexes, aged 2-11 years, were randomly assigned to receive either caudal analgesia with 1.25 ml/kg of bupivacaine 0.2% (Caudal group; n = 20) or a QLB with 0.5 ml/kg of bupivacaine 0.2% (TiQLB group; n = 20) in addition to standard general anesthesia. Time to first analgesia was the primary outcome. Total analgesic consumption in the first 24 h postoperatively, pain scores, and the incidence of side effects were the secondary outcomes.

RESULTS

The mean time to first analgesic requirement was significantly longer in the TiQLB group than in the Caudal group (18.8 ± 5.1 vs. 6.7 ± 0.7 h, P < 0.001). Total ketorolac consumption and pain scores were significantly lower in the TiQLB group (P < 0.001). A few cases of mild postoperative nausea and vomiting were noted among patients in both groups; however, the difference was not statistically significant. No incidence of pruritus, shivering, or respiratory depression was noted.

CONCLUSIONS

Analgesia after the ultrasound-guided TiQLB with bupivacaine was superior to that after the ultrasound-guided caudal block, with similar side effects.

Intrasacral Meningocele Complicating Caudal Analgesia in a 6-Year-Old Child After 3 Previous Uneventful Caudals: A Case Report

A 6-year-old male undergoing bilateral hydrocelectomy was to receive caudal analgesia after induction of general anesthesia. After insertion of the caudal needle, cerebrospinal fluid was unexpectedly aspirated and the caudal was abandoned. The surgeon performed bilateral ilioinguinal nerve blocks just before incision. Surgery was uneventful. The patient had difficulty ambulating postoperatively, and a detailed neurologic examination revealed quadriceps weakness. A lumbosacral magnetic resonance imaging (MRI) revealed a sacral meningocele. By the next morning, quadriceps function had returned, and he was ambulating normally. The ilioinguinal block was most likely deep to the internal oblique muscle and produced femoral nerve dysfunction.

Comparison of caudal epidural block with paravertebral block for renal surgeries in pediatric patients: A prospective randomised, blinded clinical trial

STUDY OBJECTIVE

This study was undertaken to compare the analgesic efficacy of ultrasound-guided single-shot caudal block with ultrasound-guided single-shot paravertebral block in children undergoing renal surgeries.

DESIGN

Randomised, interventional, blinded clinical trial.

SETTING

Operating rooms of All India Institute of Medical Sciences, New Delhi, India.

PATIENTS

50 children aged 2-10 years, of ASA status I/II, posted for elective renal surgeries.

INTERVENTIONS

The children were randomised into two groups (Group C-caudal block, Group P-paravertebral block). After induction of general anesthesia, single-shot caudal or paravertebral block was performed under ultrasound guidance, with 0.2% ropivacaine with 1:200000 adrenaline.

MEASUREMENTS

Time to first rescue analgesia, time to perform blocks, intraoperative and post-operative hemodynamics, post-operative FLACC scores, incidence of complications, parental satisfaction scores were recorded.

MAIN RESULTS

Children in Group P had significantly longer duration of analgesia (p < 0.0004) than Group C. Post-operative FLACC scores (p < 0.005) and analgesic requirements (p < 0.0004) were lower in Group P. The mean fentanyl requirement over 24 h in group P was 0.56 ± 0.82 μg/kg, compared to 1.8 ± 1.2 μg/kg in group C. Parents in Group P reported greater satisfaction (p < 0.02). No complications were seen in either of the groups.

CONCLUSION

This study showed superior analgesia and parental satisfaction with single-shot paravertebral block in comparison to single-shot caudal block for renal surgeries in children. However, the block performance in children requires adequate expertise and practice.

Regional anaesthesia in neonates, infants and children: an educational review

Prophylactic analgesia with local anaesthesia is widely used in children and has a good safety record. Performing regional blocks in anaesthetised children is a safe and generally accepted practice. When compared with adults, lower concentrations of local anaesthetics are sufficient in children; the onset of a block occurs more rapidly but the duration is usually shorter. Local anaesthetics have a greater volume of distribution, a lower clearance and a higher free (non-protein-bound) fraction. The recommended maximum dose has to be calculated for every individual. Peripheral blocks provide analgesia restricted to the site of surgery, and some of them have a very long duration of action. Abdominal wall blocks, such as transverse abdominis plane or ilio-inguinal nerve block, should be performed with the aid of ultrasound. Caudal anaesthesia is the single most important technique. Ropivacaine 0.2% or levobupivacaine 0.125 to 0.175% at roughly 1 ml  kg⁻¹ is adequate for most indications. Clonidine and morphine can be used to prolong the duration of analgesia. Ultrasound is not essential for performing caudal blocks, but it may be helpful in case of anomalies suspected at palpation and for teaching purposes. The use of paediatric epidural catheters will probably decline in the future because of the potential complications.

Revisiting the surface anatomy of the sciatic nerve in the gluteal region in children using computed tomography

No anatomy text specifically describes the course of the sciatic nerve (SN) in the gluteal region in children. Anatomical information is largely derived from cadaveric studies of adults, so accurate anatomical information about the location of the SN in children is required. The aim of this study is to assess the surface anatomy of the SN in children using computed tomography (CT). After excluding studies with pelvic pathology, 75 CT scans were analyzed. Three groups were selected for analysis (0-2, 4-6, and 8-10 years). The position of the SN was measured between the posterior superior iliac spine (PSIS) and the ischial tuberosity (IT) and between the IT and the greater trochanter (GT) using 3-dimensional images. In the 0-2 age group, the SN crossed the middle third of a line between the PSIS and the IT in 94% and the GT and the IT in 80% of cases. In the 4-6 age group, the SN crossed the middle third of a line between the PSIS and the IT in 96% and the GT and the IT in 87%. In the 8-10 age group, the SN crossed the middle third of a line between the PSIS and the IT in 100% and the GT and the IT in 71%. The findings indicate that the SN in children is most accurately located in the middle third along a line drawn from the PSIS to the IT and the GT to the IT. Our study is the first to provide anatomical CT data from living children to guide interventions in the gluteal region.

Should we abandon landmark-based technique for caudal anesthesia in neonates and infants?

BACKGROUND

Caudal anesthesia is a landmark-based technique with ultrasound guidance occasionally used in the absence of landmarks. The current surface landmark remains a popular approach due to its desirable success rate. However, incomplete ossification of the posterior vertebral elements can make this procedure for neonatal caudal anesthesia difficult. The aim of this study was to describe the anatomical relationship of the posterior superior iliac spines (PSISs) to the sacral cornua in infants using ultrasound.

METHODS

A total of 26 healthy infants (17 female; mean age 13 weeks) were scanned by an experienced radiologist in the prone position with hip and knee joints flexed. The PSISs and sacral cornua were identified clinically then using ultrasound to assess whether these markings corresponded with the clinical markings. The distance between the PSISs and the distance between the tip of the PSIS and tip of the sacral cornu were measured using ultrasound.

RESULTS

The PSISs were clinically identified in all babies, but the sacral cornua were not palpable in four babies (15%). The PSISs and sacral cornua were easily visualized using ultrasound in all participants. The mean distance between the two left and right PSISs was 3.4 ± 0.5 cm; the mean distance between the PSISs and cornu was 2.5 ± 0.5 cm on the left and right.

CONCLUSION

This study showed that the current landmark (equilateral triangle) for infant caudal anesthesia is unreliable. Importantly, the sacral hiatus is clinically identifiable only if the sacral cornua are palpable; otherwise, using ultrasound is essential.