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

Study of caudal ropivacaine with or without dexmedetomidine for postoperative analgesia in paediatric genitourinary infraumbilical surgery: a double-blinded randomized controlled trial

Various studies have described the use of Dexmedetomidine with local anaesthetic drugs in caudal blocks for the management of postoperative pain in children. This study was designed to determine the analgesic effect of caudal Dexmedetomidine with Ropivacaine in paediatric genitourinary infraumbilical surgeries. Postoperative analgesic effects of caudal Ropivacaine with or without Dexmedetomidine in paediatric genitourinary infraumbilical were evaluated. This study was a prospective, interventional, comparative study conducted after ethical approval from the institute. Informed expressed consent was taken from each patient's guardians. The sample size was calculated to be 31 in each group. The two groups were randomly assigned and the intervention involved caudal epidural injection with either Ropivacaine combined with Dexmedetomidine or Ropivacaine with Normal Saline. Children receiving Ropivacaine with Dexmedetomidine had a significantly prolonged duration of analgesia compared to those receiving Ropivacaine alone (840.35 ± 149.97 vs. 412.90 ± 93.46 min, P < 0.001). Postoperative rFLACC scores were consistently lower in the Dexmedetomidine group, indicating better pain control (P < 0.05 at 6, 12, and 24 h). Total analgesic consumption was lower in the Dexmedetomidine group (500.67 ± 212.92 vs. 741.75 ± 268.06 mg, P < 0.01). No significant differences in adverse effects were observed between the groups. The addition of Dexmedetomidine to Ropivacaine in caudal epidural significantly prolongs analgesia, improves pain control, and reduces analgesic consumption in paediatric genitourinary infraumbilical surgeries.

Ultrasound estimates of the epidural depth in the paramedian sagittal oblique and transverse median planes: the correlation between estimated and actual depth to the epidural space in children with scoliosis

INTRODUCTION

The present study aimed to compare the correlation and agreement of epidural depth estimation using ultrasound in the paramedian sagittal oblique (PSO) versus the transverse median (TM) plane relative to the actual epidural depth observed during midline epidural punctures in children with scoliosis.

METHODS

In this prospective observational study, we enrolled 55 children aged 3-14 years with thoracolumbar scoliosis (Cobb angle >10°) requesting postoperative epidural analgesia. Ultrasound imaging was performed to estimate the distance from the skin to the epidural space in the bilateral PSO and TM planes. An anesthesiologist performed midline epidural puncture and measured the actual epidural depth from the skin to the epidural space. The correlation and degree of agreement between the ultrasound-estimated and actual epidural depths were investigated using Pearson's and concordance correlation coefficients. The image quality of the ligamentum flavum and posterior dura mater was compared.

RESULTS

In the PSO view, where the larger of the two measurements from both sides was used, both Pearson's and concordance correlation coefficients for comparing the actual epidural and ultrasound-estimated depths were significantly higher than those in the TM view (0.964 vs 0.930, p value=0.002; 0.952 vs 0.892, p value=0.004, respectively). The ligamentum flavum-posterior dura mater unit was more easily distinguished in the PSO view than in the TM view (72.7% vs 38.2%, p value<0.001).

CONCLUSIONS

The PSO view can be a reliable guide to facilitate epidural puncture in children with scoliosis with better visualization.

TRIAL REGISTRATION NUMBER

NCT04877964.

Pneumorrhachis with spontaneous pneumomediastinum in pediatric patients: An 11-year retrospective study in Southern Taiwan

BACKGROUND

Although uncommon, available evidence suggests that pneumorrhachis (PR) with spontaneous pneumomediastinum (SPM) in adulthood is usually benign and self-limiting. This study aimed to review our experience and identify the risk factors of PR in pediatric patients with SPM.

METHODS

Between September 2007 and September 2017, SPM in patients aged ≤18 years was retrospectively reviewed and clinical features and outcomes between SPM patients with and without PR were analyzed.

RESULTS

In total, thirty consecutive occurrences of SPM in 29 patients were finally identified and classified into SPM (n = 24) and SPM plus PR (n = 6) groups. No significant differences in received interventional exams, prophylactic antibiotic administration or restriction of oral intake between the two groups were found. Both groups were treated with hospitalization predominantly; but the SPM plus PR group tended to have longer length of hospital stay (median 5.5 vs. 3 days, p = 0.08). PR was observed more frequently in patients with abnormal serum C-reactive protein (CRP) levels (>5 mg/L), identified predisposing factors, and those with more severe grade of SPM (p = 0.005, 0.001 and < 0.001, respectively). On multivariable regression analysis, the SPM plus PR group exhibited more predisposing factors than did the SPM group (coefficient: 0.514, standard error: 0.136, p < 0.001). All patients were successfully treated without morbidity and mortality.

CONCLUSION

Although patients with pneumorrhachis retained a higher CRP level, more identified predisposing factors and prolonged inpatient care, conservative management without an extensive work-up would be an appropriate and favorable strategy in pediatrics with concurrent SPM and PR.

[Ultrasound-guided caudal block with ropivacaine in infraumbilical surgeries in pediatric patients]

Background

The use of local anesthetics as part of multimodal analgesia is an attractive concept in pediatric patients, since the evaluation and management of pain is a challenge in children under 7 years of age. Despite having guidelines and multiple studies on volume calculation, no safe and effective recommendation has been issued.

Objective

To demonstrate that ultrasound-guided caudal block with a dose of 0.75 mL/kg of 0.2% ropivacaine has the same analgesic effect as a dose of 1.2 mL/kg.

Material and methods

Randomized, prospective, longitudinal, comparative equivalence clinical trial. One hundred patients 0-7 years of age scheduled for elective or emergency infraumbilical surgery were enrolled between April 2021 and January 2022. Children were randomized 1:1 to be assigned to ultrasound-guided caudal block.

Results

100 patients divided into two groups with 0.2% ropivacaine volumes (0.75 mL vs. 1.2 mL). Both groups demonstrated the trans-anesthetic and post-anesthetic sedoanalgesia variables without significant differences for both groups on the FLACC pain scale after surgery and in recovery (p > 0.5), in the pain reassessment on the FLACC scale in the office called chronic pain (p > 0.5) in both groups. No complications were reported in the follow-up consultations and no arrhythmias were reported in both groups during surgery.

Conclusions

the results of both groups did not show differences between a volume of 0.75 mL and 1.2 mL, the administration of 0.2% ropivacaine is favored with the use of ultrasound, which allows effective administration of lower doses of local anesthetic with reduced risk of complications. It is necessary to carry out studies in other types of surgery to compare the use of less volume of local anesthetic compared to the Melman formula used in this study.

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.

Monitored epidural catheter placement-ultrasound-guided neurostimulation-aided thoracic catheter placement via caudal route for perioperative analgesia in neonatal thoracotomies: A technical feasibility study

In this case series, we investigated the feasibility of combining ultrasound and neurostimulation for inserting a stimulating epidural catheter in the thoracic epidural space through the caudal route in neonates. Twelve neonates undergoing tracheo-oesophageal fistula repair under general anaesthesia were studied. The catheter was visible on ultrasound as a hyperechoic dot in the epidural space. Inadvertent high placement was identified in two neonates with neurostimulation, in whom the catheter was withdrawn to the thoracic epidural space, and the position was confirmed on ultrasound. A 0.5 ml/kg bolus dose of 0.125% bupivacaine injected through the epidural catheter was imaged in real-time in the epidural space. Block was effective in 10 neonates; two needed an additional local anaesthetic (LA) bolus. To conclude, ultrasound with neurostimulation facilitates accurate positioning of the caudally placed epidural catheter to the mid-thoracic level in neonates.

Comparison of landmark and real-time ultrasound-guided epidural catheter placement in the pediatric population: a prospective randomized comparative trial

Background

Epidural block placement in pediatric patients is technically challenging for anesthesiologists. The use of ultrasound (US) for the placement of an epidural catheter has shown promise. We compared landmark-guided and US-guided lumbar or lower thoracic epidural needle placement in pediatric patients.

Methods

This prospective, randomized, comparative trial involved children aged 1–6 years who underwent abdominal and thoracic surgeries. Forty-five children were randomly divided into two groups using a computer-generated random number table, and group allocation was performed by the sealed opaque method into either landmark-guided (group LT) or real-time ultrasound-guided (group UT) epidural placement. The primary outcome was a comparison of the procedure time (excluding US probe preparation). Secondary outcomes were the number of attempts (re-insertion of the needle), bone contacts, needle redirection, skin-to-epidural distance using the US in both groups, success rate, and complications.

Results

The median (interquartile range) time to reach epidural space was 105.5 (297.0) seconds in group LT and 143.0 (150) seconds in group UT (P = 0.407). While the first attempt success rate was higher in the UT group (87.0% in UT vs. 40.9% in LT; P = 0.004), the number of bone contacts, needle redirections, and procedure-related complications were significantly lower.

Conclusions

The use of US significantly reduced needle redirection, number of attempts, bone contact, and complications. There was no statistically significant difference in the time to access the epidural space between the US and landmark technique groups.

Dura-to-spinal cord distance at different vertebral levels in Indian children: A retrospective computerized tomography scan-based study

Background:

Neuraxial techniques provide good postoperative analgesia for painful procedures in the pediatric population. However, any injury to the spinal cord can lead to irreversible long-term effects.

Aims:

We aimed to evaluate dura-to-cord (DTC) distance from computerized tomography (CT) images of thoracolumbar spine in pediatric age group (1–16 years) at T_8–9, T_9–10, and L_1–2 interspaces to identify the safe space for epidural insertion in Asian children.

Settings and Design:

It was a retrospective study including 141 children aged 1–16 years who underwent routine CT scan of the thoracolumbar region for unrelated diagnostic indications.

Materials and Methods:

Patients with spinal abnormalities were excluded. Sagittal CT images of the thoracolumbar spine were obtained to calculate the DTC at T_8–9, T_9–10, and L_1–2 interspaces. The measurements at all levels were obtained perpendicular to the long axis of the vertebral body.

Statistical Analysis Used:

Continuous data were depicted as mean with standard deviations. The categorical data were presented as counts with percentages.

Results:

The mean DTC distance at T_8–9, T_9–10, and L_1–2 interspaces was 3.51 ± 0.98 mm (95% confidence interval [CI]: 3.35–3.67), 2.73 ± 0.94 mm (95% CI: 2.57–2.89), and 2.83 ± 1.08 mm (95% CI: 2.66–3.02), respectively. A significant difference was found between the genders at T_9–10 (P = 0.02) and L_1–2 levels (P = 0.04). No difference in DTC was found in toddlers, preschool children, school-going children, and adolescents. DTC at T_8–9 showed a significant correlation with age (R² = 0.0479; P = 0.04), weight (R² = 0.038; P = 0.02), and height (R² = 0.037; P = 0.03).

Conclusion:

Thoracic epidural space can be used in children and adolescents for epidural catheter placement. T_8–9 level showed maximum DTC distance and significant correlation with age, height, and weight in CT imaging in the present study.

Comparative evaluation of landmark technique and ultrasound-guided caudal epidural injection in pediatric population: A systematic review and meta-analysis

BACKGROUND

Caudal block is a common regional anesthesia technique in pediatrics with landmark method predominantly being practiced. Ultrasound-guided technique provides real-time visualization of the structures and injection while performing caudal block. We performed this meta-analysis to determine the utility of ultrasound in caudal blocks in children over the landmark-based technique.

METHODS

Randomized controlled trials comparing ultrasound-guided caudal blocks and landmark technique in pediatrics were searched from databases-PubMed, Embase, Scopus, and CENTRAL from inception until August 2020. The primary objective was success rate between the two techniques and secondary objectives included time to perform the block, first puncture success, and complications.

RESULTS

Five trials with 904 participants were included for this meta-analysis. There was no difference in success rate between the two techniques (Risk ratio-1.07; 95% CI [0.97, 1.18]; p = .15). Time to perform the block was similar (Mean difference-8.88 s; 95% CI [-21.64, 39.40; p = .57) while first puncture success was higher with ultrasound-guided technique (Risk ratio-1.31; 95% CI [1.15, 1.49]; p = .0001). Complications like vascular puncture and needle misplacement were lower in the ultrasound group, and no serious complications were seen in any patient. Needle visualization and sacral canal distension were seen in 82% and 97.5% of the cases, respectively, in ultrasound group.

CONCLUSION

Ultrasound-guided caudal injection does not improve the success rate or time to perform the block but results in higher first puncture success and lower incidence of complications compared to landmark technique.

Epidural space "ballooning" during local anaesthetic injection in infants and children: An ultrasound observational study

BACKGROUND

Infants and children require a larger dose of a local anaesthetic (LA) to establish epidural analgesia than adults, but the reason for this remains unclear. We hypothesised that prominent ventro-dorsal expansion of the epidural space limits cranio-caudal spread of LA in infants. Accordingly, we studied the dimensions of the epidural space with real-time ultrasound (US) before and after epidural injection.

METHODS

Ninety-six infants and children aged 0-12 years who underwent abdominal surgery under combined epidural and general anaesthesia were examined in this prospective observational study. Using a micro-convex probe, US recordings of the posterior epidural space were performed while a LA (0.5 ml kg^-1 ) was infused at 0.54 ml s^-1 . The width in the ventro-dorsal dimension (VDD) of the posterior epidural space before and after injection was recorded; the change in VDD was defined as "ballooning". Correlations between "ballooning" and patient age, body mass index, and volume and rate of LA administration were analysed.

RESULTS

"Ballooning" correlated positively but weakly with age (R²  = 0.25; p < .001) and the infused LA volume (R²  = 0.32; p < .001). The "magnitude of ballooning" ("ballooning" per ml of injected LA) correlated negatively but weakly with age (R²  = 0.27; p < .001).

CONCLUSIONS

"Magnitude of ballooning" of the epidural space become inconspicuous with growing during epidural injection. This effect may slow the cranio-caudal spread of LA and explain partially why larger volumes of LA are required to effect a block in children.

Complications in paediatric regional anaesthesia: a narrative review

Paediatric anaesthesia and paediatric regional anaesthesia are intertwined. Currently, almost all paediatric patients posted for surgery could and should be given a regional block unless and until contraindicated. This is because the scope, techniques, and their benefits have a wide range and complications are rare. The first report that used regional anaesthesia in children was in 1898, and over the last 120 years it has been developed with many scholars’ wisdom, ideas and publications. Paediatric regional anaesthesia (PRA) has many advantages but requires experience and expertise. For a long-time, exclusively landmark-guided techniques were used and gradually the development of new techniques such as the use of neuro-stimulator and ultrasound-guided (USG) blocks developed into PRA. Especially, the application of ultrasonography (US) has revolutionised the practice of PRA. Few limitations of regional anaesthesia can be tackled by the use of US, leading to shorter time to perform the block, reduced time for block onset and use of a smaller volume of local anaesthetic. Life threatening complications of regional anaesthesia are rare and the riskbenefit ratio is favourable. However, a thorough insight into RA complications, no matter how rare they are, is essential for safe practice. This is because they can be life-threatening, and no matter how small the percentage is, when complications occur, for that individual patient statistics is irrelevant.

Alternative way to find sacral hiatus for blind caudal block - Based on 3D pelvis CT anthropometry: A retrospective study

The aim of this study is to develop an alternative way to locate the sacral hiatus for blind caudal block from the anthropometrical data measured on 3D pelvic CT. The intersection of the line connecting two sacral cornua and the midline is considered the ideal point (IP) for caudal block. The mean length from the coccyx tip to the IP was measured using 3D pelvic CT images in 30 men and 30 women and was 6.5 cm and 6.0 cm, respectively. For the conventional method group, we used the conventional equilateral triangle method to find the sacral hiatus, which was named conventional method group needling point (CNP). For the experimental method group, the point 6.5 cm or 6.0 cm (mean length from the coccyx tip to the IP) away from the coccyx tip was called the experimental method group needling point (ENP). Drawing the three points of the IP, CNP, and ENP on the same patient's 3D pelvic CT, we compared the distance from the IP to the CNP with the distance from the IP to the ENP. We propose that the experimental method is comparable to the conventional method in locating the sacral hiatus, which is crucial for a successful caudal block procedure. Anthropometric measurements and virtual comparative test between two methods were done on the 3D pelvis CT. In men, the distance from the CNP to the IP was 0.8 ± 0.5 cm in the conventional method group, while the distance from the ENP to the IP was 0.5 ± 0.4 cm in the experimental method group (p < 0.05). In women, the same distances were 1.5 ± 0.8 cm and 0.7 ± 0.3 cm, respectively (p < 0.05). In conclusion, finding a point of 6.5 cm from the coccyx tip in men and 6.0 cm in women could be an alternative way to find the sacral hiatus for blind caudal block.