Caudal block: the 'no turn technique'

Comparison of Landmark-guided, Nerve Stimulation-guided, and Ultrasound-guided Techniques for Pediatric Caudal Epidural Anesthesia: A Prospective Randomized Controlled Trial

OBJECTIVES

Traditionally, caudal epidurals are performed by a landmark-guided approach using the loss of resistance technique. Improvisations to increase the success rate can be attained by implementing modalities, namely neurostimulation and ultrasound, but there is a paucity of literature comparing these 3 approaches. Here, we compare the 3 techniques in terms of the success rate.

MATERIALS AND METHODS

The primary outcome of this study was to compare the success rate of the 3 techniques, and the secondary outcome was the blood or cerebrospinal fluid aspiration during the procedure. It was a prospective, randomized, open-label parallel-group study. Three hundred children aged 1 to 5 years scheduled for circumcision, hypospadias repair, and minor lower extremity surgeries were enrolled after taking written informed consent from the parents.

RESULTS

Demographic profiles were comparable in terms of age, weight, sex distribution, and types of surgeries. Success rates in landmark-guided, neurostimulation-guided, and ultrasound-guided were 97%, 97%, and 98%, respectively which was comparable (P=0.879). There was no significant difference in the incidence of blood or cerebrospinal fluid aspiration.

DISCUSSION

We found a similar success rate of the caudal epidural block by using landmark-guided, nerve stimulation-guided, or ultrasound-guided techniques in children aged 1 to 5 years with normal anatomy.

Caudal Anesthesia for Pediatric Subumbilical Surgery, Less Load on the Postoperative Recovery Unit

Introduction

Caudal epidural anesthesia, when used as a sole method for surgical anesthesia, has favorable effects on the recovery duration and the time spent in the recovery unit. In this study we made a retrospective analysis of pediatric surgery operations under local, regional and general anesthesia. We aimed to find shorter postoperative recovery times with local and regional anesthesia.

Materials and methods

Data of the pediatric patients undergone subumbilical surgery during the two-year period in Pediatric Surgery clinic were collected. The patients’ age, sex, surgery type, anesthesia and airway control routes, as well as duration of anesthesia, operation and recovery were obtained.

Results

Data of 937 patients were analyzed, of whom 811 (86.6%) were males. Caudal anesthesia was performed in 240 patients (25.6%) and the mean age of these patients was 3.83 ± 3.00 years. The patients with caudal and local anesthesia spent significantly less time in the postoperative recovery unit, compared with general anesthesia groups (P < 0.001).

Conclusion

Caudal anesthesia as a sole method for pediatric subumbilical surgery is a relatively safe method. Patients having operation under caudal anesthesia have faster discharge times from postoperative recovery units, compared with general anesthesia. This probably reduces recovery unit expenditures.

Determining the extent of the dural sac for the performance of caudal epidural blocks in newborns

BACKGROUND

Information regarding the position and relationship of vital structures within the caudal canal is important for anesthesiologists who perform a caudal block. This information can be acquired by anatomical dissection, with ultrasound technology, or radiological studies.

AIMS

The aim of this study was to determine the position of the dural sac in neonates by measuring the distance of the termination of the dural sac from the apex of the sacral hiatus in neonatal cadavers.

METHODS

After careful dissection, the distance from the apex of the sacral hiatus to the dural sac was measured in a sample of neonatal cadavers.

RESULTS

In 39 neonatal cadavers, the mean distance from the apex of the sacral hiatus to the dural sac was 10.45 mm. The range of this distance was between 4.94 and 26.28 mm. The mean distance for females was 9.64 mm (range from 6.66 to 15.09); that for males was 10.90 mm (range between 4.94 and 26.28). Linear regression with the log of this distance as the outcome variable gave an estimated 3.3% increase in the distance for each 1 cm increase in the length of the neonate (95% CI for this proportion was 1.91-4.71).

CONCLUSION

Anesthesiologists should be aware of the short distance between the sacral hiatus and the dural sac when performing caudal blocks, the shortest distance was 4.94 mm. Armed with this knowledge, caudal techniques should be modified to improve the safety and reduce the risk of complications, such as dural puncture.

[Central blockades in Pediatrics: A review of current literature]

Pediatric neuraxial anesthesia is an effective tool that can be used as a supplement or alternative to general anesthesia. However, there have always been doubts about its usefulness and risk-benefit ratio. The purpose of this review is to describe the current role of central blockades in pediatric patients, upgrade practical and safety aspects, and review the latest technological advances applied to this procedure.

Caudal blocks

Caudal anesthesia is the single most important pediatric regional anesthetic technique. The technique is relatively easy to learn (1), has a remarkable safety record (2), and can be used for a large variety of procedures. The technique has been reviewed in the English (3) and French (4) literature, as well as in German guidelines (5) and in pediatric anesthesia textbooks (6).

The caudal space in fetuses: an anatomical study

PURPOSE

The caudal epidural space is a popular site for analgesia in pediatrics. High variation in blind needle placement is common during caudal epidurals, increasing the risk of intravascular and intrathecal spread. Knowledge of safe distances and angles for accessing the caudal epidural space in premature infants can improve the safety of caudal epidural blocks.

METHODS

Thirty-nine fetuses with crown-heel length between 33 and 50 cm, corresponding to gestational age of 7-9 months, were included. The dorsal surface of the sacrum from the fourth lumbar vertebra to the tip of the coccyx was dissected, following which measurements were taken on dorsal surface and midsagittal sections. The angle of depression of the needle was measured using a goniometer following the two-step method of needle insertion.

RESULTS

Right and left sacral cornua were palpable in 23 of 39 fetuses (58.97%). Termination of dural sac was at S2 in most of the fetuses (53.84%), whereas the apex of the sacral hiatus was at S3 in most (58.97%). The distance from the apex of the hiatus to the termination of dura ranged from 3 to 13 mm; the anteroposterior distance of the canal at the apex of the hiatus ranged from 1.72 to 4.38 mm. All sacral parameters correlated with crown-heel length except inter-cornual distance, depth of canal at hiatus, and height of sacral hiatus.

CONCLUSION

Distances and angles for accessing the caudal epidural space in fetuses do not provide all parameters for safe performance of caudal epidural blocks in premature and low birth weight infants because the apex of the sacral hiatus and the termination of the dura show wide variation in location.

Caudal epidural block in children: comparison of needle insertion parallel with caudal canal versus conventional two-step technique

This study compared the technique of inserting the needle for caudal epidural blockade in a single pass parallel to the caudal canal versus the conventional technique of approaching the caudal canal with the needle at a steeper angle. Seventy-five patients, aged 0 to 72 months, scheduled for urological surgery were prospectively enrolled in this study. Patients were randomly divided into two groups: a conventional method group (caudal block performed with conventional needle insertion, n=40) and a new method group (needle inserted into the skin at an angle of 200 and into the caudal space without redirection, n=35). Two anaesthetists (A, B) performed the caudal blocks. For anaesthetist A, the mean time required (standard deviation) to perform needle insertion in the conventional method group was 2.2 (0.8) minutes and in the new method group 1.1 (0.7) minutes (P = 0.03). For anaesthetist B the mean time (standard deviation) to perform needle insertion in the conventional method group was 2.1 (1.1) minutes and in the new method group 1.3 (0.8) minutes (P = 0.04). Successful block was considered as first pass placement of the needle in the caudal canal confirmed (after placement) by ultrasound imaging, and the absence of a bloody tap. Subcutaneous placement of the needle after the first attempt occurred in two cases in the conventional method group and three cases in the new method group. Bloody tap occurred in four cases, all in the conventional method group and none in the new method group. When required, the second pass was successful in all cases.

A survey of pediatric caudal extradural anesthesia practice

BACKGROUND

Caudal extradural blockade is one of the most commonly performed procedures in pediatric anesthesia. However, there is little information available on variations in clinical practice.

OBJECTIVES

To perform a survey of members of the Association of Paediatric Anaesthetists of Great Britain and Ireland who undertake caudal anesthesia.

METHODS

An 'online' World Wide Web questionnaire collected information on various aspects of clinical practice. The survey ran from April to June 2008.

RESULTS

There were 366 questionnaires completed. The majority of respondents had >5 years of pediatric experience and performed up to ten caudal extradural procedures a month. The commonest device used was a cannula (69.7%) with 68.6% using a 22G device. There was a trend toward the use of a cannula in those anesthetists with <15 years experience, while those with >15 years experience tended to use a needle. Most anesthetists (91.5%) did not believe that there was a significant risk of implantation of dermoid tissue into the caudal extradural space. The majority used a combination of clinical methods to confirm correct placement. Only 27 respondents used ultrasound. The most popular local anesthetics were bupivacaine (43.4%) and levobupivacaine (41.7%). The most common additives were clonidine (42.3%) and ketamine (37.5%). The caudal catheter technique was used by 43.6%. Most anesthetists (74%) wear gloves for a single shot caudal injection.

CONCLUSIONS

This survey provides a snapshot of current practice and acts a useful reference for the development of enhanced techniques and new equipment in the future.

Hemodynamic effects of levobupivacaine after pediatric caudal anesthesia evaluated by transesophageal doppler

BACKGROUND

The aim of this study is to determine if there are significant differences in hemodynamic effects between combined general-regional anesthesia using levobupivacaine 0.25% 2 ml x kg(-1) via the caudal route in comparison with balanced general anesthesia using continuous infusion of remifentanil in young children undergoing genitourinary surgery.

PATIENTS AND METHODS

62 ASA I-II pediatric patients (12 female, 50 male) aged 6 months to 7 years undergoing genitourinary surgery were included in the study. Patients were randomly allocated into one of two groups of 31 patients each. Group Caud received caudal blockade with levobupivacaine 0.25% 2 mg x kg(-1) in combined general-regional anesthesia and Group Gen received balanced general anesthesia with remifentanil. The noninvasive hemodynamic parameters were measured in each group 5 min after induction of general anesthesia or caudal block (Tcaud), after further 5 min coincident with skin incision (Tsi), 10 min after skin incision (T10i), at the end of surgical procedure (Tend). The time between Tcaud and Tsi was 10 min and the measurements during the interval time T10i-Tend were performed every 15 min according to the duration of surgical procedures.

RESULTS

There was a decrease in all measured hemodynamic parameters at skin incision. The decreases occurred in both groups with those in the caudal group occurring at skin incision and those in the balanced anesthesia group occurring at 10 min after skin incision. These variations showed no significant differences for any of the stated outcomes; neither between the groups at each time point nor in the caudal in comparison with baseline measurements.

CONCLUSIONS

Using transesophageal Doppler no differences in hemodynamic parameters could be detected between balanced general anesthesia with either caudal levobupivacaine or remifentanil infusion. Both techniques showed good hemodynamic stability with only minor changes from baseline over time which are unlikely to be of clinical significance except possibly in patients with preexisting cardiovascular compromise. Other studies with noninvasive monitoring in a larger population are required to better understand the consequences of caudal blockade on CO and on regional blood flow in infants.