Determination of the optimal angle for needle insertion during caudal block in children using ultrasound imaging

Effectiveness of ultrasonography-guided caudal epidural steroid injection compared to the fluoroscopic application

BACKGROUND

Caudal epidural steroid injection (CESI) has been increasingly used for treating lower back pain. However, there is still significant controversy about the efficacy and safety of different imaging techniques used to guide CESI. In this context, the objective of this study is to compare the efficacies of fluoroscopy- and ultrasonography-guided CESI in patients with chronic lower back pain.

METHODS

The population of this retrospective, observational study consisted of all consecutive patients who underwent CESI for lower back pain between 2018 and 2020. Of the 371 patients included in the study sample, 192 had undergone fluoroscopyguided CESI (Group F) and 179 ultrasonography-guided CESI (Group U). Patients' pain and functional statuses were evaluated using the visual analog scale (VAS) and Oswestry Disability Index (ODI) immediately before (baseline) and after the procedure (postintervention day 0-D0), during the second week (D15), the first month (D30), and the third month (D90) after the procedure.

RESULTS

The mean age of Group F was significantly higher than that of Group U (p < 0.001). The number of patients with lumbar dischernia was significantly higher in Group U, whereas the number of patients with spinal stenosis and lumbar disc hernia + spinal/lumbar stenosis was significantly higher in Group F (p = 0.001). The baseline and D0 ODI scores were significantly lower in Group U than in Group F (p = 0.006 and p = 0.017, respectively). There was no significant difference between the groups in other VAS and ODI scores (p > 0.05). Intragroup analyses revealed significant reductions in VAS and ODI scores over the follow-up period till D30 compared to the baseline scores in each group (p < 0.001). The decrease recorded in the ODI score between the D15 and baseline measurements was significantly higher in Group F than in Group U (p = 0.006).

DISCUSSION

The study findings indicated that ultrasound-guided CESI was as effective as fluoroscopy-guided CESI in treating chroniclower back pain.

On the physics of ultrasound transmission for in-plane needle tracking in guided interventions

Objective.In ultrasound (US) guided interventions, the accurate visualization and tracking of needles is a critical challenge, particularly during in-plane insertions. An inaccurate identification and localization of needles lead to severe inadvertent complications and increased procedure times. This is due to the inherent specular reflections from the needle with directivity depending on the angle of incidence of the US beam, and the needle inclination.Approach.Though several methods have been proposed for improved needle visualization, a detailed study emphasizing the physics of specular reflections resulting from the interaction of transmitted US beam with the needle remains to be explored. In this work, we discuss the properties of specular reflections from planar and spherical wave US transmissions respectively through multi-angle plane wave (PW) and synthetic transmit aperture (STA) techniques for in-plane needle insertion angles between 15°-50°.Main Results.The qualitative and quantitative results from simulations and experiments reveal that the spherical waves enable better visualization and characterization of needles than planar wavefronts. The needle visibility in PW transmissions is severely degraded by the receive aperture weighting during image reconstruction than STA due to greater deviation in reflection directivity. It is also observed that the spherical wave characteristics starts to alter to planar characteristics due to wave divergence at large needle insertion depths.Significance.The study highlights that synergistic transmit-receive imaging schemes addressing the physical properties of reflections from the transmit wavefronts are imperative for the precise imaging of needle interfaces and hence have strong potential in elevating the quality of outcomes from US guided interventional practices.

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.

Recent trends in paediatric regional anaesthesia

Paediatric regional anaesthesia today is one of the fastest growing and exciting aspects of paediatric anaesthesia, which requires an ongoing fervour to learn. Application of paediatric regional anaesthesia in neonates, infants, toddlers and children is undertaken to treat perioperative pain without disturbing the physiological milieu with additional advantages elaborated in the review. The available choices, traditional methods and the most recently described methods are discussed with emphasis on their advantages and disadvantages. Clear pointers for selection of the blocks are also discussed. To present a holistic overview of this rapidly growing subject, a comprehensive literature search was performed in May 2019 in MEDLINE, PubMed and Google Scholar to retrieve articles pertaining to all the above topics. The keywords used in various combinations included 'Central neuraxial, blocks, Paediatric(s)', 'Peripheral Nerve blocks', 'Safety, controversies, regional, anaesthesia'.

Caudal and epidural blocks in infants and small children: historical perspective and ultrasound-guided approaches

In infants and small children, ultrasound (US) guidance provides ample anatomical information to perform neuraxial blocks. We can measure the distance from the skin to the epidural space in the US image and can refer to it during needle insertion. We may also visualize the needle or a catheter during real-time US-guided epidural catheterization. In cases where direct needle or catheter visualization is difficult, US allows predicting successful puncture and catheterization using surrogate markers, such as dura mater displacement, epidural space widening due to drug injection, or mass movement of the drug within the caudal space. Although many experienced anesthesiologists still prefer to use conventional techniques, prospective randomized controlled trials using US guidance are providing increasing evidence of its advantages. The use of US-guided regional block will gradually become widespread in infants and children.

Ultrasound-guided versus conventional injection for caudal block in children: A prospective randomized clinical study

STUDY OBJECTIVE

The aim of this study was to compare the efficacies of ultrasound guided sacral hiatus injection and conventional sacral canal injection performed for caudal block in children.

DESIGN

Randomized controlled clinical trial.

SETTING

Operating rooms of university hospital of Erzurum, Turkey.

PATIENTS

One hundred-thirty four children, American Society of Anesthesiologists I-II, between the ages of 5 and 12, scheduled for elective phimosis and circumcision surgery.

INTERVENTIONS

Patients assigned to two groups for ultrasound guided caudal block (Group U, n=68) or conventional caudal block (Group C, n=66). Caudal solution was prepared as 0.125% levobupivacaine plus 10mcg/kg morphine (total volume: 0.5ml/kg), and was administered to both groups.

MEASUREMENTS

The block performing time, the block success rate, the number of needle puncture, the success at first puncture and the complications were recorded.

MAIN RESULTS

The block performing time and the success rate of block were similar between Group U and Group C (109.96±49.73s vs 103.17±45.12s, and 97% vs 93%, respectively p>0.05). The first puncture success rate was higher in Group U than in Group C (80% vs 63%, respectively p=0.026). No significant difference was observed between the groups with regard to the number of needle punctures (p=0.060). The rates of vascular puncture and subcutaneus bulging were higher in Group C than in Group U (8/66 vs 1/68, and 8/66 vs 0/68, respectively p<0.05).

CONCLUSIONS

Despite the limitations in central neuroaxial anesthesia we recommend the use of ultrasound since it reduces the complications and increases the success rate of first puncture in pediatric caudal injection.

Measuring the depth of the caudal epidural space to prevent dural sac puncture during caudal block in children

BACKGROUND

Caudal blocks are performed through the sacral hiatus in order to provide pain control in children undergoing lower abdominal surgery. During the block, it is important to avoid advancing the needle beyond the sacrococcygeal ligament too much to prevent unintended dural puncture. This study used demographic data to establish simple guidelines for predicting a safe needle depth in the caudal epidural space in children.

METHODS

A total of 141 children under 12 years old who had undergone lumbar-sacral magnetic resonance imaging were included. The T2 sagittal image that provided the best view of the sacrococcygeal membrane and the dural sac was chosen. We used Picture Achieving and Communication System (Centricity^® PACS, GE Healthcare Co.) to measure the distance between the sacrococcygeal ligament and the dural sac, the length of the sacrococcygeal ligament, and the maximum depth of the caudal space.

RESULTS

There were strong correlations between age, weight, height, and BSA, and the distance between the sacrococcygeal ligament and dural sac, as well as the length of the sacrococcygeal ligament. Based on these findings, a simple formula to calculate the distance between the sacrococcygeal ligament and dural sac was developed: 25 × BSA (mm).

CONCLUSION

This simple formula can accurately calculate the safe depth of the caudal epidural space to prevent unintended dural puncture during caudal block in children. However, further clinical studies based on this formula are needed to substantiate its utility.

The role of ultrasound guidance in pediatric caudal block

Objectives:

To compare the time interval of the procedure, possible complications, post-operative pain levels, additional analgesics, and nurse satisfaction in ultrasonography-guided and standard caudal block applications.

Methods:

This retrospective study was conducted in Celal Bayar University Hospital, Manisa, Turkey, between January and December 2014, included 78 pediatric patients. Caudal block was applied to 2 different groups; one with ultrasound guide, and the other using the standard method.

Results:

The time interval of the procedure was significantly shorter in the standard application group compared with ultrasound-guided group (p=0.020). Wong-Baker FACES Pain Rating Scale values obtained at the 90th minute was statistically lower in the standard application group compared with ultrasound-guided group (p=0.035). No statistically significant difference was found on the other parameters between the 2 groups. The shorter time interval of the procedure at standard application group should not be considered as a distinctive mark by the pediatric anesthesiologists, because this time difference was as short as seconds.

Conclusion:

Ultrasound guidance for caudal block applications would neither increase nor decrease the success of the treatment. However, ultrasound guidance should be needed in cases where the detection of sacral anatomy is difficult, especially by palpations.

Anatomic Differences in the Sacral Hiatus During Caudal Epidural Injection Using Ultrasound Guidance

OBJECTIVES

The aim of this study was to clarify differences in the anatomic structure of the sacral hiatus and angle of needle insertion during caudal epidural steroid injection using ultrasound guidance in patients according to sex and age.

METHODS

A total of 237 patients with low back pain with or without sciatica were included. Sonograms of the sacral hiatus were obtained, and caudal epidural steroid injection using ultrasound guidance was performed in all patients. The intercornual distance, diameter of the sacral canal, thickness of the sacrococcygeal ligament, optimal angle for needle insertion, and actual angle of needle insertion were measured.

RESULTS

Between men and women, significant differences were observed for the intercornual distance (17.7 versus 16.5 mm; P< .01) and thickness of the sacrococcygeal ligament (4.3 versus 3.9 mm; P = .02). In all patients, the thickness of the sacrococcygeal ligament (r= 0.28) and diameter of the sacral canal (r= 0.40) were positively correlated with the optimal angle for needle insertion (P < .01). In women, the thickness of the sacrococcygeal ligament (r = -0.24), diameter of the sacral canal (r = -0.27), optimal angle for needle insertion (r = -0.29), and actual angle of needle insertion (r = -0.18) were negatively correlated with age. In men, only the diameter of the sacral canal was negatively correlated with age (r = -0.30).

CONCLUSIONS

We found that the sacral hiatus has anatomic differences between patients of different sexes and ages. Understanding these differences, especially in women, may improve the safety and reliability of caudal epidural steroid injection.

Assessment of factors affecting the difficulty of caudal epidural injections in adults using ultrasound

Caudal epidural block is used to treat pain in the lower back and lower extremities. The procedure can be difficult to perform, particularly when a blind technique is being used. The authors of this study aimed to identify variables affecting the difficulty of caudal epidural blocks performed using a blind technique by measuring relevant anatomical variables using ultrasonography.

BACKGROUND:

In unaided caudal epidural block (CEB), incorrect needle insertion has been reported to occur in 15% to 38% of attempts.

OBJECTIVE:

To statistically analyze the anatomical variables affecting difficult CEB using ultrasonographic measurement.

METHODS:

Preprocedural ultrasonography was performed and the following measurements were obtained in 146 patients: the distance from the skin to the apex of the sacral hiatus; the depth of the sacral canal at the apex of the sacral hiatus; the length of the sacrococcygeal ligament between the apex of the sacral hiatus and sacral base; the distance from the skin to the apex of the sacral cornu; and the distance between the apexes of bilateral cornua. One clinician, unaware of the ultrasonographic findings, performed the injections using the landmark technique. The procedures were videotaped and were subsequently reviewed by an independent investigator.

RESULTS:

The means (± SDs) of the abovementioned measurements were 12.1±3.7 mm, 6.1±2.1 mm, 25.9±7.4 mm, 10.0±4.0 mm and 16.4±3.2 mm, respectively. Injections failed in 16 (11%) patients and were defined as difficult in 21 (14.4%) patients. The depth of the sacral canal at the apex of sacral hiatus (P<0.001) and the length of the sacrococcygeal ligament between the apex of the sacral hiatus and sacral base (P=0.001) were significant predictors of difficult CEB. Of all patients, 85.7% and 75.2% were correctly classified as difficult or not difficult, respectively. The cutoff values of the depth of the sacral canal at the apex of the sacral hiatus and the length of the sacrococcygeal ligament between the apex of the sacral hiatus and the sacral base to predict a difficult CEB were 3.7 mm and 17.6 mm, respectively.

CONCLUSIONS:

Both the depth of the sacral canal at the apex of the sacral hiatus and the length of the sacrococcygeal ligament between the apex of the sacral hiatus and sacral base are significant variables affecting the difficulty of the CEB.

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

The anatomy of the sacral hiatus and caudal canal is prone to significant variation, yet studies assessing this in the pediatric population remain limited. Awareness of the possible anatomical variations is critical to the safety and success of caudal epidural blocks, particularly when image guidance is not employed. This systematic review analyzes the available evidence on the clinical anatomy of the caudal canal in pediatric patients, emphasizing surface anatomy and internal anatomical variations. A literature search using three electronic databases and standard pediatric and anatomy reference texts was conducted yielding 24 primary and seven secondary English-language sources. Appreciating that our current landmark-guided approaches to the caudal canal are not well studied in the pediatric population is important for both clinicians and researchers.

Where is the apex of the sacral hiatus for caudal epidural block in the pediatric population? A radio-anatomic study

PURPOSE

Caudal epidural block (CEB), administered through the sacral hiatus, is a regional anesthetic technique commonly used in children. To facilitate and optimize pediatric CEB, morphometric data that may be important for the sacral hiatus have been obtained using multidetector computed tomography (MDCT).

METHODS

This study is the first radio-anatomic study designed to address this topic in children. Images of 79 children (39 girls and 40 boys between 1 and 9 years old) were divided into three groups according to age [group I (ages 1-3), group II (ages 4-6), and group III (ages 7-9)] and were retrospectively examined. Data were gathered via 3D volume-rendered images. Measurements included the height and width of the sacral hiatus, S2-S4 (sacral vertebra) distance, the distances between the poles of the unfused spinous process of each sacral vertebra, and the dimensions of an imaginary triangle formed between the right and left posterior superior iliac spines (PSIS) and the apex of the sacral hiatus.

RESULTS

The most frequently fused spinous process was at S2 level. The mean S2-S4 distance was 1.36 cm for group I, 1.78 cm for group II, and 2.17 cm for group III. There was not the imaginary equilateral triangle used in the method of finding the sacral hiatus for CEB, and the apex of this triangle did not occur at the standard level (S4) in most of the children. It was observed that the apex deriving from the most distal fused spinous process was at the level of S2 in one of two children.

CONCLUSION

Dural puncture is inevitable for CEB applied at the S2 level. Consequently, CEB should be applied below this level (range, 1.36-2.17 cm) from the midpoint of the interspinous distance between the PSIS (at the same level with S2) in children aged 1-9 years.

A randomized comparison of caudal block by sacral hiatus injection under ultrasound guidance with traditional sacral canal injection in children

BACKGROUND

There is a risk of inadvertent dural or vascular puncture for the traditional single-shot caudal block performed by inserting the needle into the sacral canal through the sacral hiatus. This prospective, randomized study was to evaluate the clinical feasibility of the hiatus injection under ultrasound guidance for caudal block in children.

METHODS

140 ASA I-II children undergoing inguinal hernia repair were randomly allocated to one of two groups (Group C or Group H, n = 70). 1 ml·kg(-1) of 0.25% ropivacaine was injected after the needle was inserted into the sacral canal in Group C, or after the needle pierced the sacrococcygeal ligament under a transverse ultrasound view in Group H. Success rate of block, puncture frequency, complications, and durations of block were recorded.

RESULTS

The success rate of block was similar between two groups (95.7% in Group C vs 92.8% in Group H, P > 0.05). The first puncture success rate was higher, and the durations of block were shorter in Group H than in Group C (92.8% vs 60% and 145 ± 23s vs 164 ± 31s, respectively P < 0.05). Bloody puncture had an incidence of 18.6% in Group C and 5.7% in Group H (P < 0.05). Subcutaneous bulging occurred in six patients (7.1%) in Group C but none in Group H (P < 0.05).

CONCLUSIONS

Sacral hiatus injection offers a reliable caudal block for pediatric inguinal hernia repair with the advantages of easier performance and fewer complications compared with traditional sacral canal injection.

Psychological and behavioral effects of chloral hydrate in day-case pediatric surgery: a randomized, observer-blinded study

BACKGROUND/PURPOSE

This prospective, randomized, and observer-blinded study was performed to evaluate the effects of oral chloral hydrate on perioperative psychological and behavioral phenomena in children.

METHODS

In total, 100 boys (age, 1-5 years) scheduled for day-case unilateral orchiopexy were randomly allocated into 2 groups and orally administered either 40 mg/kg of chloral hydrate (CH group) or placebo (control group) 30 minutes before surgery, followed by assessment of anxiety, induction compliance, emergence delirium, postoperative pain, and maladaptive behavioral changes.

RESULTS

Anxiety scores were significantly lower in the CH group compared with the control group (45.7 vs 28.8). The induction compliance of the CH group was better than that of the control group (3.2 vs 4.8). Postoperative sedation was more frequent (62.7% vs 20.4%); however, the incidence of vomiting was lower (2.0% vs 14.3%) in the CH group than in the control group. Postoperative emergence delirium and maladaptive behavior changes were similar between the 2 groups.

CONCLUSION

Decreasing preoperative anxiety with oral chloral hydrate improves induction compliance and reduces postoperative pain intensity without delaying recovery in young boys. However, chloral hydrate had little impact on emergence delirium and postoperative maladaptive behavior.

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.

The evaluation of upper leg traction in lateral position for pediatric caudal block

PURPOSE

A well-functioning caudal block is an excellent adjunct to general anesthesia, but misplaced injection results in poor analgesia as well as possibility of serious morbidity. Therefore, the purpose of this study was to evaluate the effectiveness of leg traction on success rate of caudal block in lateral position in children.

METHODS

Two hundred children, age 2 months to 6 years, ASA I and II, who underwent lower abdominal surgeries were randomized in prospective controlled clinical trial study in two groups. After induction of General anesthesia, the caudal block was performed in the lateral position with upper leg traction (L-T-) or with the standard position (S-P) (leg flexed 90°). Hemodynamicchanges, movement of lower extremity in response to surgical stimulus were evaluated.

RESULTS

There was no significant difference in caudal block's success rate between two groups at first attempt (P=0.25). In group (S-P) the procedure was successful in 60% of cases at first attempt, 25% at second,10% at third attempt and 5% failure of caudal block, whereas in the first group it was 75%, 20%, 1% and 4% of cases respectively. There were no significant differences in heart rate and blood pressure changes between two groups (P>0.05).

CONCLUSION

The success rate of pediatric caudal block in upper leg traction did not differ from that of the standard position.

Changes of dorsalis pedis artery flow pattern after caudal block in children: observational study using a duplex sonography

OBJECTIVE

To evaluate the changes of the flow velocity, the volume flow, and the diameter of dorsalis pedis artery using a duplex ultrasonography after caudal block with sevoflurane anesthesia in children.

AIM

To know the acute change in peripheral arterial flow patterns of sympathetically blocked lower limbs in anesthetized children.

BACKGROUND

Caudal analgesia in combination with general anesthesia may affect the circulatory hemodynamics due to sympatholytic vasodilating effects.

METHODS

After approval by the Ethics Committee, we evaluated the changes of peripheral hemodynamics using a duplex ultrasonography before and after a caudal block in sevoflurane-anesthetized children.

RESULTS

A caudal block using 0.15% ropivacaine 1.5 ml·kg(-1) significantly altered the arterial flow patterns; increased peak velocity (24%) and volume flow (76%), and the diameter of the dorsalis pedis artery (20%) in children. However, blood pressures and heart rates were not affected significantly by caudal block.

CONCLUSIONS

Duplex sonographic measurements indicate that a caudal block changes the flow patterns of the dorsalis pedis artery significantly in the anesthetized children.

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.

Ultrasound as a screening tool for proceeding with caudal epidural injections

OBJECTIVE

To study the anatomical structure of the sacral hiatus using ultrasound. Based on the sonographic images of the sacral hiatus, the feasibility of caudal epidural injection can then be assessed.

DESIGN

Case-controlled study.

SETTING

Rehabilitation outpatient clinic in a tertiary medical center.

PARTICIPANTS

Patients (N=47; 20 women, 27 men) with low back pain and sciatica who were to receive caudal epidural injection treatments were recruited into this study.

INTERVENTIONS

Sonographic images of the sacral hiatus were obtained from all the patients. An ultrasound machine capable of examining musculoskeletal tissues with real-time linear-array ultrasound transducer was used to measure the distance between the anterior wall and posterior wall of the sacral hiatus (diameter of the sacral hiatus) and the distance between bilateral cornua.

MAIN OUTCOME MEASURES

Diameter of the sacral canal and distance between bilateral cornua measured in millimeters.

RESULTS

The mean diameter of the sacral canal was measured to be 5.3+/-2.0 mm in our recruited patients. The mean distance between bilateral cornua was measured to be 9.7+/-1.9 mm. Caudal epidural injections failed in 7 patients. In these 7 patients, 4 had very small diameter of the sacral canal (1.6, 1.2, 1.4, and 1.5 mm). In 1 man, sonographic images revealed a closed sacral hiatus (no sacral canal diameter can be measured). Two patients revealed flow of fresh blood into the syringe while checking for the escape of cerebrospinal fluid after the needles were inserted into the sacral canal. For safety reasons, steroid injections were not performed in these 2 patients.

CONCLUSIONS

Ultrasound may be used as an effective screening tool for caudal epidural injections. Anatomic variations of the sacral hiatus can be clearly observed using ultrasound. Sonographic images indicating a closed sacral canal and sacral diameters ranging from 1.2 to 1.6mm may suggest a higher failure rate in caudal epidural injection.

Anatomic consideration of caudal epidural space: a cadaver study

The knowledge of sacral hiatus anatomy is imperative in clinical situations requiring caudal epidural block for various diagnostic and therapeutic procedures of the lumbosacral spine to avoid failure and dural injury. In this study, a detailed anatomic study of the sacral region was carried out on 49 male adult Indian cadavers. Dorsal surface of sacral region was dissected to study sacral cornua, sacral hiatus, and the dimensions of triangle formed by the right and left posterosuperior iliac spines with apex of the hiatus. Midsagittal sections were subjected for various anatomical measurements. The angle of needle insertion and the depth of caudal space were noted. Cornu was not palpable bilaterally in 7 (14.3%) and palpable unilaterally in 12 (24.5%) specimens. Mean (standard deviation) distance between apex of hiatus and coccyx tip was 57.5 (8.7) mm and length of sacrococcygeal ligament was 34.2 (7.4) mm. The dimensions of the triangle were found to be interchangeable in 25 cadavers. Once the needle is introduced into the canal after penetrating the sacrococcygeal ligament, it should not be advanced >5 mm to prevent dural puncture. The level of maximum curvature of sacrum was S3 in 34 (69.4%) of cases. The dural sac was found to terminate at S2 in 41 (83.6%). The mean (SD) angle of depression of the needle was 65.7 (5.5) (range 58-78). The measurements described for the identification of the sacral hiatus, optimal angle of depression, and depth of the needle may improve the safety and reliability of a caudal epidural block.

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.

Bladder puncture associated with caudal block in a pediatric patient undergoing day surgery: A case report

Although single-shot caudal blockade is known as a relatively safe procedure, it is not always without complications. We present a case of accidental bladder puncture that was identified with fluoroscopy by chance after single-shot caudal blockade in a 17-months-old, 12 kg boy who underwent inguinal hernioplasty.

Are peripheral and neuraxial blocks with ultrasound guidance more effective and safe in children?

BACKGROUND AND AIMS

The efficacy and safety of ultrasound guided (USG) pediatric peripheral nerve and neuraxial blocks in children have not been evaluated. In this review, we have looked at the success rate, efficacy and complications with USG peripheral nerve blocks and compared with nerve stimulation or anatomical landmark based techniques in children.

METHODS

All suitable studies in MEDLINE, EMBASE Drugs and Cochrane Evidence Based Medicine Reviews: Cochrane Database of Systemic Reviews databases were identified. In addition, citation review and hand search of recent pediatric anesthesia and surgical journals were done. All three authors read all selected articles independently and a consensus was achieved. All randomized controlled trials (RCTs) comparing USG peripheral and neuraxial blocks with other techniques in children were included.

RESULTS

Ultrasound guidance has been demonstrated to improve block characteristics in children including shorter block performance time, higher success rates, shorter onset time, longer block duration, less volume of local anesthetic agents and visibility of neuraxial structures.

CONCLUSION

Clinical studies in children suggest that US guidance has some advantages over more traditional nerve stimulation-based techniques for regional block. However, the advantage of US guidance on safety over traditional has not been adequately demonstrated in children except ilio-inguinal blocks.

Caudal midazolam does not affect sevoflurane requirements and recovery in pediatric day-case hernioplasty

BACKGROUND

This prospective, randomized, double-blind study aimed to determine whether caudal midazolam combined with ropivacaine affects anesthetic requirements, recovery profiles, and post-operative analgesia compared with ropivacaine alone in pediatric day-case hernioplasty.

METHODS

Sixty boys (2-5 years old) received caudal injections of 0.2% ropivacaine 1 ml/kg and epinephrine 1 : 200,000 with (RM group) or without (R group) 50 microg/kg of midazolam under sevoflurane anesthesia. The sevoflurane requirement was determined by adjusting to a bispectral index score=50.

RESULTS

Concentrations of end-tidal sevoflurane (ETsevo%) after induction were similar in both groups. After caudal block, ETsevo% before and after surgical stimuli did not show significant intra- or intergroup differences. Recovery characteristics, including post-operative sedations, were similar in both groups. Post-operative pain scores were significantly lower in the RM group than the R group.

CONCLUSIONS

Caudal midazolam (50 microg/kg) added to 2% ropivacaine did not influence sevoflurane requirement or recovery but improved post-operative analgesia compared with ropivacaine alone in pediatric day-case hernioplasty.