A Comparison of High Volume/Low Concentration and Low Volume/High Concentration Ropivacaine in Caudal Analgesia for Pediatric Orchiopexy

Methods of prolonging the effect of caudal block in children

Caudal epidural blockade is one of the most frequently administered regional anesthesia techniques in children. It is a supplement during general anesthesia and for providing postoperative analgesia in pediatrics for sub-umbilical surgeries, especially for genitourinary surgeries. However, the duration of the analgesic effect is occasionally unsatisfactory. In this review, we discuss the main advantages and disadvantages of different techniques to prolong postoperative analgesia for single-injection caudal blockade in children. A literature search of the keywords "caudal", "analgesia", "pediatric", and "children" was performed using PubMed and Web of Science databases. We highlight that analgesic quality correlates substantially with the local anesthetic's type, dose, the timing relationship between caudal block and surgery, caudal catheterization, and administration of epidural opioids or other adjuvant drugs.

The median effective concentration of ropivacaine for ultrasound-guided caudal block in children: a dose-finding study

PURPOSE

To determine the 50% minimum effective concentration (MEC50) and the 95% effective concentration (MEC95) of ropivacaine for ultrasound-guided caudal block during hypospadias repair surgery of pediatric patients.

METHODS

Children were enrolled with the American Society of Anesthesiologists (ASA) physical status I-II undergoing elective hypospadias repair surgery. Children were grouped into two age groups: toddlerhood (1-3 years old) and preschool (3-6 years old). We measured The MEC50 using Dixon's up-and-down method. The first children received the caudal block with 1.0 mL/kg of 0.15% ropivacaine. We determined each subsequent patient's concentration based on the previous patient's response and adjusted the concentration in intervals of 0.015%. Meanwhile, the probit regression analysis obtains 95% effective concentration (MEC95). In addition, we recorded the general condition, adverse events, and postoperative pain of each child.

RESULTS

46 children undergoing elective hypospadias repair surgery were included in this study, 22 in the toddlerhood group and 24 in the preschool group. Of the total number of patients, the caudal block was successful in 25 (54%) and failed in 21 (46%). The MEC50 of 1 ml/kg ropivacaine was 0.102% (95% CI 0.099%, 0.138%) in the toddlerhood group and 0.129% (95% CI 0.124%, 0.138%) in the preschool group. The MEC95 of 1 ml/kg ropivacaine was 0.148% (95% CI 0.131%, 0.149%) in the toddlerhood group and 0.162% (95% CI 0.134%, 0.164%) in the preschool group. Our results showed that ropivacaine concentration was statistically different between preschool children and toddlers (P < 0.001). None of the adverse events occurred.

CONCLUSIONS

This study showed that children in the preschool group required higher concentrations of ropivacaine than children in the toddler group during ultrasound-guided sacral block combined with non-intubated general anesthesia. At the same time, this method of anesthesia is safe and effective for children undergoing surgery for hypospadias.

Analgesic Effects of Regional Analgesic Techniques in Pediatric Inguinal Surgeries: A Systematic Review and Network Meta-Analysis of Randomized Controlled Trials

BACKGROUND

Various regional analgesic techniques have been used in pediatric inguinal surgery to facilitate postoperative recovery. However, each technique's relative performance was undetermined owing to the lack of quantitative analysis.

METHODS

We systematically searched MEDLINE, Cochrane Library, EMBASE, and Web of Science for randomized controlled trials that compared regional analgesia in pediatric inguinal surgeries. After critical study screening and selection, a random-effects network meta-analysis was performed. The primary outcome was the time to the first rescue analgesic after surgery, and the secondary outcomes were the number of patients requiring rescue analgesics after surgery, postoperative pain scores, incidence of postoperative nausea and vomiting, and other adverse events.

RESULTS

This network meta-analysis included 69 randomized controlled trials (4636 patients) that compared 10 regional analgesic techniques. Our study revealed that the quadratus lumborum and transversus abdominis plane blocks had the longest time to the first rescue analgesic after pediatric inguinal surgeries, by 7.7 hours (95% confidence interval [CI], 5.0-10.3) and 6.0 hours (95% CI, 3.9-8.2) when compared with the control group, respectively. In the subgroup involving only inguinal hernia repair, the quadratus lumborum block significantly prolonged the time to the first rescue analgesic than all other regional analgesics. In contrast, in the subgroup involving orchidopexies, only the caudal block significantly prolonged the time to the first rescue analgesic when compared with the control group (4.1 hours; 95% CI, 0.7-7.5). Wound infiltration and landmark-based ilioinguinal-iliohypogastric block had relatively poor analgesic effects than other regional analgesics. No serious adverse effects related to the regional analgesic techniques were reported in any of the included studies.

CONCLUSIONS

The quadratus lumborum and transversus abdominis plane blocks had the longest time to the first rescue analgesic and the least rescue analgesic requirement for pediatric inguinal surgeries. Specifically, the quadratus lumborum block had the longest analgesic duration in inguinal hernia repair, and the caudal block was found to be the only regional analgesia that extended the time to the first rescue analgesic in pediatric orchidopexy. Most included randomized controlled trials had some concern or a high risk of bias, and future studies should focus on providing high-quality evidence to further clarify the analgesic effects of regional analgesia for pediatric inguinal surgeries.

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.

Comparison between two different concentrations of a fixed dose of ropivacaine in interscalene brachial plexus block for pain management after arthroscopic shoulder surgery: a randomized clinical trial

Background

Only a few studies have evaluated the differences between varying concentrations of a fixed dose of local anesthetics. This study was conducted to compare the effects of two different concentrations of a fixed dose of ropivacaine used in ultrasound-guided interscalene brachial plexus block.

Methods

This prospective, randomized, double-blind study included 62 patients who underwent arthroscopic surgery under general anesthesia. The patients were randomly assigned to receive ultrasound-guided interscalene block with 75 mg of ropivacaine at one of two concentrations: 0.75% (10 ml; Group C) or 0.375% (20 ml; Group V). Time to onset of sensory blockade, degree of blockade, pulmonary function changes, analgesic duration of the interscalene block, postoperative opioid requirement within 24 h, postoperative pain scores, satisfaction, and incidence of complications were recorded.

Results

Although the time to onset of sensory blockade was shorter for Group C (P = 0.015), successful blockade was achieved at 30 min after the interscalene block in both groups. The analgesic duration of the interscalene block was not significantly different between the groups. The amount of opioid used within 24 h after surgery was significantly reduced for Group V compared with Group C (P = 0.016). The rest of the parameters did not show any significant differences between the two groups.

Conclusions

Compared with 10 ml of 0.75% ropivacaine, interscalene block with 20 ml of 0.375% ropivacaine could be effective for the reduction of postoperative opioid requirement within 24 h after surgery despite it might not prolong the analgesic duration.

A comparison of the postoperative analgesic effectiveness of low dose caudal epidural block and US-guided dorsal penile nerve block with in-plane technique in circumcision

BACKGROUND

Circumcision can be performed under sedo-analgesia, general anesthesia, or regional anesthesia. It may cause serious postoperative pain and patients often require additional analgesia. Dorsal penile nerve block (DPNB) and caudal epidural block are commonly used regional anesthesia methods to provide effective postoperative pain control in circumcision.

OBJECTIVE

In this prospective observational study, we aimed to investigate the postoperative analgesic efficiency of DPNB with the ultrasound (US)-guided in-plane technique and single-dose caudal epidural block in circumcision.

STUDY DESIGN

Male patients aged 4-12 years in the ASA I-II group, who were scheduled for circumcision, were included in the study. A caudal epidural block or US-guided DPNB with the in-plane technique was administered under general anesthesia before the operation. Postoperative pain was evaluated using the Children's Hospital Eastern Ontario Pain Scale (CHEOPS) and Faces Pain Scale-Revised (FPS-R). Postoperative analgesic need and parental satisfaction were also noted.

RESULTS

There were 140 patients in our study. The number of patients receiving a caudal block (n = 70) and DPNB block (n = 70) was equal. Side effects were only seen in five patients in the caudal group. No side effects were seen in patients in the DPNB group. Analgesics were required in 3.6% of the patients in the caudal group and none of the patients in the DPNB group postoperatively. CHEOPS mean scores in the caudal block group were found to be statistically significantly higher than in the penile block group. FPS-R 24th^. hour mean score was statistically significantly higher in the caudal block group (P < 0.001). Postoperative parental satisfaction in the penile block group was found to be statistically significantly better than in the caudal block group (P = 0.028).

DISCUSSION

This study demonstrated that DPNB conducted with the US-guided in-plane technique was more effective than caudal block in providing postoperative analgesia. The parental satisfaction was also higher, and no side effect was seen in the DPNB group.

CONCLUSION

DPNB conducted with the US-guided in-plane technique is a simple and safe regional anesthesia method used to provide effective postoperative analgesia for male circumcision. Complications related to DPNB can be prevented with the help of the real-time imaging provided by ultrasound.

Population Pharmacokinetics of Levobupivacaine During Transversus Abdominis Plane Block in Children

BACKGROUND

Levobupivacaine is commonly used during transversus abdominis plane (TAP) block in pediatric patients. However, the dosing regimen is still empirical, and the pharmacokinetic properties of levobupivacaine are not considered. Here, the pharmacokinetics of levobupivacaine during an ultrasound-guided TAP block were evaluated to optimize dosing regimen, regarding the between-subject variability (BSV) and the volume of levobupivacaine injected.

METHOD

The clinical trial (prospective, randomized, double-blind study protocol) was conducted in 40 children aged 1-5 years, who were scheduled for inguinal surgery. Each patient received 0.4 mg/kg of levobupivacaine with a volume of local anesthesia solution adjusted to 0.2 mL/kg of 0.2% or 0.4 mL/kg of 0.1% levobupivacaine. Blood samples were collected at 5, 15, 20, 25, 30, 45, 60, and 75 minutes after the block injection. The population pharmacokinetic analysis was performed using the NONMEM software.

RESULTS

From the pharmacokinetic parameters obtained, median Cmax, tmax,, and area under the concentration versus time curve were 0.315 mg/L, 17 minutes, and 41 mg/L·min, respectively. BSV of clearance was explained by weight. At the dose regimen of 0.4 mg/kg, none of the infants showed signs of toxicity, but in 13 patients, TAP block failed. After analysis, BSV for absorption rate constant, distribution volume, and clearance were 81%, 47%, and 41%, respectively. Residual unexplained variability was estimated to be 14%.

CONCLUSIONS

For improved efficiency in the pediatric population, the dose of levobupivacaine should be greater than 0.4 mg/kg. Children's weight should be considered to anticipate any risk of toxicity.

Comparison between Post-Operative Analgesic Efficacy of Low-Concentration High-Volume and High-Concentration Low-Volume Combinations of Ropivacaine for Transverse Abdominis Plane Block in Pediatric Open Inguinal Hernia Repair

Transverse abdominis plane (TAP) block can provide post-operative analgesia in children undergoing open inguinal hernia repair. However, the optimal anesthetic dose, and concentration for TAP block in the pediatric population, is not well defined. This study compared the post-operative analgesic effect of TAP block between low-concentration, with high-volume (LCHV) and high-concentration, with low-volume (HCLV) combinations of local anesthetic. Forty-four patients who underwent open inguinal hernia repair were randomly assigned to two groups. The patients in the LCHV group received 0.67 mL/kg of 0.15% ropivacaine. Whereas, those in the HCLV group received 0.4 mL/kg of 0.25% ropivacaine. Both groups received the same amount of ropivacaine (1 mg/kg). The primary outcome measure was the face, leg, activity, cry, consolability (FLACC) scale score at post-anesthetic care unit (PACU; T1). FLACC scale score at T1 was significantly lower in the HCLV group (2.91 versus 1.43; mean difference, −1.49; 95% confidence interval, −0.0245 to −2.936; p = 0.0464). FLACC scale scores one hour and six hours after the surgery were not different between the two groups. This study reports better post-operative analgesic effects after unilateral open inguinal hernia repair with 1 mg/kg of 0.25% ropivacaine than 1 mg/kg of 0.15% ropivacaine at PACU.

Transversus Abdominal Plane Block in Children: Efficacy and Safety: A Randomized Clinical Study and Pharmacokinetic Profile

BACKGROUND

The transversus abdominis plane (TAP) block has become a common regional anesthesia technique for pain management in a wide variety of abdominal procedures. Evidence to support any particular local anesthetic regimen as well as pharmacokinetic and systemic toxicity risks of TAP block remain insufficiently studied in children. The aim of this study was to compare the analgesic effects and investigate pharmacokinetic profile of levobupivacaine after ultrasound-guided TAP block using a low volume/high concentration (LVHC) or a high volume/low concentration (HVLC) solution in children.

METHODS

This prospective randomized study included children scheduled for day-case inguinal surgery. Children were randomized to receive TAP block using 0.4 mg·kg levobupivacaine as either HVLC (0.2 mL·kg of 0.2% levobupivacaine) or LVHC (0.1 mL·kg of 0.4% levobupivacaine). The primary outcome was the number of children who required opioid rescue analgesia postoperatively. Pharmacokinetic profile study of levobupivacaine was also performed.

RESULTS

Seventy patients were equally randomized, and 65 were included in the final analysis. Seventy-one percent of patients did not require any postoperative opioid analgesia. The number of patients who received rescue analgesia was 12 (35%) in the LVHC group and 7 (23%) in the HVLC group (relative risk, 0.64; 95% confidence interval [CI], 0.29-1.42; P = .26). Mean pain scores (FLACC [faces, legs, activity, cry, and consolability]) at postanesthesia care unit discharge did not differ between LVHC and HVLC groups, respectively, 0.39 ± 0.86 and 1 ± 1.71 with mean group difference -0.60 (95% CI, -1.27 to 0.06; P = .08). The pharmacokinetic profile of levobupivacaine was comparable in the 2 groups: the mean total and free levobupivacaine peak concentrations were 379 ± 248 and 3.95 ± 3.16 ng·mL, respectively, occurring 22.5 ± 11 minutes after injection. The highest total and free levobupivacaine concentrations collected, respectively, 1360 and 15.1 ng·mL, remained far below theoretical toxic thresholds.

CONCLUSIONS

In children, quality of postoperative pain control provided by TAP block using levobupivacaine 0.4 mg·kg administered as either HVLC or LVHC did not differ and was associated with a very low risk of local anesthetic systemic toxicity.

Peribulbar block combined with general anesthesia in babies undergoing laser treatment for retinopathy of prematurity: a retrospective analysis

Background and objectives

Currently there is no agreement regarding which one is the most adequate anesthetic technique for the treatment of retinopathy of prematurity. Peribulbar block may reduce the incidence of oculocardiac reflex and postoperative apnea. The goal of this study was to report the outcomes of peribulbar block, when combined with general anesthesia, for the laser treatment for retinopathy of prematurity, in premature babies.

Methods

A retrospective analysis of anesthetic records of all babies who underwent laser treatment for retinopathy of prematurity from January 2008 through December 2015 in a tertiary hospital was performed.

Results

During that period a total of six babies was submitted to laser treatment for retinopathy of prematurity, all under peribulbar block combined with general anesthesia. A single infratemporal injection of 0.15 mL.kg⁻¹ per eye ropivacaine 1% or 0.75% was performed. At the end of the procedure, all babies resumed spontaneous ventilation. No perioperative complications were reported.

Conclusions

Peribulbar block was a safe anesthetic technique in our sample considered.

[Peribulbar block combined with general anesthesia in babies undergoing laser treatment for retinopathy of prematurity: a retrospective analysis]

BACKGROUND AND OBJECTIVES

Currently there is no agreement regarding which one is the most adequate anesthetic technique for the treatment of retinopathy of prematurity. Peribulbar block may reduce the incidence of oculocardiac reflex and postoperative apnea. The goal of this study was to report the outcomes of peribulbar block, when combined with general anesthesia, for the laser treatment for retinopathy of prematurity, in premature babies.

METHODS

A retrospective analysis of anesthetic records of all babies who underwent laser treatment for retinopathy of prematurity from January 2008 through December 2015 in a tertiary hospital was performed.

RESULTS

During that period a total of six babies was submitted to laser treatment for retinopathy of prematurity, all under peribulbar block combined with general anesthesia. A single infratemporal injection of 0.15mL.kg^-1 per eye ropivacaine 1% or 0.75% was performed. At the end of the procedure, all babies resumed spontaneous ventilation. No perioperative complications were reported.

CONCLUSIONS

Peribulbar block was a safe anesthetic technique in our sample considered.

The analgesic effects of rectal diclofenac versus rectal paracetamol following caudal-bupivacaine for pediatric day-case inguinal herniotomies: a randomized controlled prospective trial

BACKGROUND

Postoperative pain is a common complaint in day-case inguinal herniotomy, thus there is a need to provide effective analgesia. This study compared the postoperative analgesic effects of the combinations of caudal-bupivacaine and rectal diclofenac with caudal-bupivacaine and rectal-paracetamol in children scheduled for daycase inguinal-herniotomy.

METHODS

Ninety children of ASA I scheduled for elective day-case inguinal-herniotomy were randomly assigned into Group A (1ml/kg of 0.25% caudal-bupivacaine and 1mg/kg rectal-diclofenac), Group B (1ml/kg of 0.25% caudal-bupivacaine and 30mg/kg rectal paracetamol) and Group C (1ml/kg of 0.25% caudal-bupivacaine). The duration of analgesia, pain scores, postoperative analgesic consumption and side effects were assessed and recorded. Data collected was analyzed with the statistical package for social sciences 17 for windows.

RESULTS

Eighty-seven children completed the study, and it was found that the duration of analgesia was prolonged in Group A compared to Groups B and C (p<0.01).

CONCLUSION

Caudal-bupivacaine and rectal-diclofenac combination provides a more prolonged postoperative analgesia, and lower pain score compared to caudal-bupivacaine and rectal-paracetamol combination or caudal-bupivacaine alone.

LEVEL OF EVIDENCE

Level 1 evidence treatment study. Randomized controlled trials with adequate statistical power to detect differences (narrow confidence intervals) and follow up >80%.

Influence of caudal block on postoperative oliguria in infants undergoing bilateral ureteroneocystostomy: a retrospective analysis

BACKGROUND

Caudal block has been widely used in children undergoing genitourinary surgery. However, the influence of caudal block on postoperative oliguria is unclear.

AIM

The aim of this study was to assess the effect of caudal block on urinary flow through the reimplanted ureter after ureteroneocystostomy and the incidence of postoperative oliguria in infants.

METHODS

This retrospective study analyzed the medical records of 121 infants aged less than 12 months who underwent bilateral ureteroneocystostomy for vesicoureteral reflux at a tertiary medical center. In all study infants, a ureteral catheter was placed in one of the two ureters in order to relieve the clinical consequences of transient ureteral obstruction and a urethral catheter was placed at the end of the ureteroneocystostomy procedure. Urinary output was assessed separately for each catheter. Logistic regression analysis was performed to identify the risk factors for oliguria from the urethral catheter.

RESULTS

Among the 121 patients, 63 (52%) received caudal block (caudal block group) and 58 (48%) did not (no caudal block group). Patient characteristics, preoperative vesicoureteral reflux grade and renal function, and intraoperative profiles were comparable between the groups. The incidence of oliguria from the urethral catheter for 8 h after the surgery was significantly higher in the caudal block group than in the no caudal block group. However, the incidence of oliguria from the ureteral catheter was comparable between the groups. In multivariate analysis, oliguria from the urethral catheter was associated with caudal block, anesthesia duration, and intraoperative dexamethasone administration. The odds for oliguria was 3.069-fold greater in patients who received caudal block than in those who did not (95%CI, 1.303-7.228, P = 0.010). On the other hand, intraoperative dexamethasone reduced the risk of oliguria.

CONCLUSION

Caudal block may be associated with postoperative oliguria in infants undergoing ureteroneocystostomy.

A review of perioperative anesthesia and analgesia for infants: updates and trends to watch

This review focuses on pharmacokinetics and pharmacodynamics of opioid and non-opioid analgesics in neonates and infants. The unique physiology of this population differs from that of adults and impacts drug handling. Morphine and remifentanil are described as examples of older versus recently developed opiates to compare and contrast pharmacokinetics and pharmacodynamics in infants. Exploration of genetics affecting both pharmacokinetics and pharmacodynamics of opiates is an area of active research, as is the investigation of a new class of mu-opiate-binding agents which seem selective for analgesic pathways while having less activity in pathways linked to side effects. The kinetics of acetaminophen and of ketorolac as examples of parenteral non-steroidal analgesics in infants are also discussed. The growth in regional anesthesia for peri-operative analgesia in infants can fill an important role minimizing intra-operative anesthetic exposure to opioids and transitioning to post-operative care. Use of multi-modal techniques is recommended to decrease undesirable opiate-related side effects in this vulnerable population.

Caudal block with 3 mg/Kg Bupivacaine for intraabdominal surgery in pediatric patients: a randomized study

Background: Caudal block with the use of an adequate dose of bupivacaine, and combined with a general anesthesia (GA) provides intra-operative anesthesia and postoperative analgesia. No study has examined the use of 3 mg/Kg bupivacaine for intra-abdominal surgery in pediatric patients in clinical practice.

Objective: Compare the effectiveness of three mg/Kg bupivacaine administered as 1.2 mL/Kg 0.25% bupivacaine and 1.5 mL/Kg 0.2% bupivacaine for caudal block in pediatric patients undergoing intra-abdominal surgery.

Methods: In a randomized, double-blinded clinical trial, patients (age: 6 months -7 years) were randomly assigned into one of two groups (n= 40) to receive a caudal block with either 1.2 mL/Kg 0.25% bupivacaine (group A) or 1.5 mL/Kg 0.2% bupivacaine (group B), with morphine 50 μg/Kg. The effectiveness of intra-operative anesthesia, complications, and requirements for post-operative analgesia were evaluated.

Results: Data were available for 74 pediatric patients. There were no significant differences between the two groups in baseline characteristics. Intra-operatively, the numbers of patients who required a rescue analgesic were comparable between the groups (67% in group A and 63% in group B). The numbers of patients who required a muscle relaxant were also comparable between groups (49% in group A and 57% in group B). The time from discontinuation of the volatile anesthetic to extubation was significantly shorter in group B (9.5±1.1 minutes) than group A (14.3±0.9 minutes), p < 0.01. The time from initial caudal block to the first analgesic required in the recovery room was significantly longer in group B (202±45 minutes) than in group A (149±27 minutes). The time from the caudal block to the first analgesic required in the ward was significantly longer in group B (10.4±3.1 hours) than in group A (8.2±2.0 hours). Overall fentanyl requirements were comparable between groups, 52.5±2.0 μg in group A and 49.5±3.0 μg in group B.

Conclusion: Caudal block by either 1.2 mL/Kg 0.25% bupivacaine plus morphine 50 μg/Kg or 1.5 mL/Kg 0.2% bupivacaine plus morphine 50 μg/Kg provided effectively equivalent intra-operative analgesia and surgical relaxation. However, a caudal block with 1.5 mL/Kg 0.2% bupivacaine plus morphine 50 μg/Kg provided superior prolonged analgesic advantages compared with 1.2 mL/Kg 0.25% bupivacaine plus morphine 50 μg/Kg in pediatric patients undergoing intra-abdominal surgery.

A Comparison of Three Different Volumes of Levobupivacaine for Caudal Block in Children Undergoing Orchidopexy and Inguinal Hernia Repair

OBJECTIVE

The aim of this study was to compare the efficacy of 3 different volumes of 0.25% levobupivacaine caudally administered on the effect of intra- and postoperative analgesia in children undergoing orchidopexy and inguinal hernia repair.

SUBJECTS AND METHODS

Forty children, aged 1-7 years, American Society of Anesthesiologists (ASA) physical status I and II, were randomized into 3 different groups according to the applied volumes of 0.25% levobupivacaine: group 1 (n = 13): 0.6 mL∙kg-1; group 2 (n = 10): 0.8 mL∙kg-1; and group 3 (n = 17): 1.0 mL∙kg-1. The age, weight, duration of anesthesia, onset time of intraoperative analgesic, dosage, and addition of intraoperative fentanyl were compared among the groups. The time to first use of the analgesic and the number of patients who required analgesic 24 h after surgery in the time intervals within 6 h, between 6 and 12 h, and between 12 and 24 h postoperatively were evaluated among the groups. Statistical analyses were performed with a Dunnett t test, ANOVA, or Kruskal-Wallis test and χ2 test. Logistic regression analysis was used in order to examine predictive factors on duration of postoperative analgesia.

RESULTS

Age, weight, duration of anesthesia, onset time of intraoperative analgesic, dosage, and addition of intraoperative fentanyl were similar among the groups. The time to first analgesic use did not differ among the groups, and logistic regression modelling showed that using the 3 different volumes of levobupivacaine had no predictive influence on duration of postoperative analgesia. The numbers of patients who required analgesics within 6 h (3/2/3), between 6 and 12 h (3/1/3), and between 12 and 24 h (1/0/2) after surgery were similar among the groups.

CONCLUSION

The 3 different volumes of 0.25% levobupivacaine provided the same quality of intra- and postoperative pain relief in pediatric patients undergoing orchidopexy and inguinal hernia repair.

Impact of caudal block on postoperative complications in children undergoing tubularised incised plate urethroplasty for hypospadias repair: a retrospective cohort study

This study aimed to assess the association between caudal block and postoperative complications after tubularised incised plate urethroplasty. The medical records of 388 paediatric patients who underwent urethroplasty at a tertiary medical centre were analysed retrospectively. Among the 342 patients included, 216 patients received a caudal block and 72 (21.1%) patients suffered surgical complications. The number of patients having surgical complications was significantly greater among patients who received a caudal block than among patients who did not receive a caudal block (53 (24.5%) versus 19 (15.1%), respectively, p = 0.04). Based on multivariate logistic regression analysis, duration of surgery, caudal block and hypospadias types were independent risk factors for the surgical complications. Patients with caudal block had an odds ratio of 2.1 (95% CI, 1.14-3.81, p = 0.018) for the development of postoperative complications compared with patients without caudal block. This analysis demonstrates that caudal block is associated with surgical complications after tubularised incised plate urethroplasty.

Comparison of caudal and intravenous dexamethasone as adjuvants for caudal epidural block: A double blinded randomised controlled trial

Background and Aims:

Dexamethasone has a powerful anti-inflammatory action with significant analgesic benefits. The aim of this study was to compare the efficacy of dexamethasone administered through intravenous (IV) and caudal route on post-operative analgesia in paediatric inguinal herniotomy patients.

Methods:

One hundred and five paediatric patients undergoing inguinal herniotomy were included and divided into three groups. Each patient received a single caudal dose of ropivacaine 0.15%, 1.5 mL/kg combined with either corresponding volume of normal saline (Group 1) or caudal dexamethasone 0.1 mg/kg (Group 2) or IV dexamethasone 0.5 mg/kg (Group 3). Baseline, intra- and post-operative haemodynamic parameters, pain scores, time to rescue analgesia, total analgesic consumption and adverse effects were evaluated for 24 h after surgery. Unpaired Student's t-test and analysis of variance were applied for quantitative data and Chi-square test for qualitative data. Time to first analgesic administration was analysed by Kaplan–Meier survival analysis and log-rank test.

Results:

Duration of analgesia was significantly longer (P < 0.001), and total consumption of analgesics was significantly lower (P < 0.001) in Group II and III compared to Group I. The incidence of nausea and vomiting was higher in Group I (31.4%) compared to Group II and III (8.6%).

Conclusions:

Addition of dexamethasone both caudally or intravenously as an adjuvant to caudal 0.15% ropivacaine significantly reduced the intensity of post-operative pain and prolonged the duration of post-operative analgesia with the significant advantage of caudal over IV route.

Ultrasound visibility of spinal structures and local anesthetic spread in children undergoing caudal block

This study assessed ultrasound visibility of spinal structures in children and observed the extent of local anesthetic spread within the epidural space during caudal block. Spinal structures were evaluated with ultrasound from the sacral area to the thoracic area in 80 children, and drug spread levels were observed after caudal injection of 0.5, 1.0, 1.25 and 1.5 mL/kg local anesthetic. The conus medullaris, dural sac and dura mater were easily identified with ultrasound in most children. However, ligamentum flavum visibility declined with increasing vertebral level and markedly decreased at the thoracic level in children older than 7 mo or heavier than 8.5 kg. Drug spread was higher with increasing volume (p < 0.001) and in children ≤12 mo more than children >12 mo (p < 0.001); drug spread was significantly correlated with age (R(2) = 0.534). Spread levels assessed with ultrasound were roughly two to three segments lower than those in previous radiologic studies.

Transient abdominal wall deformity in an infant Blaming the caudal?

Locoregional anesthesia is an important aspect of perioperative analgesia. It decreases requirements for anesthetic agents and opioids, decreases the surgical stress response, and provides postoperative analgesia. Nonetheless, pediatric patients, especially infants, demonstrate specificities towards regional anesthesia techniques, as an increased sensitivity to local anesthetics (LA) and a higher ease of LA spread especially when using blocks that rely on the volume of LA and its spread as those used for abdominal wall analgesia or caudal. Thus, we present a case of transient abdominal wall deformity following caudal anesthesia in an infant.

Analgesic efficacy of caudal dexamethasone combined with ropivacaine in children undergoing orchiopexy

BACKGROUND

Epidural administration of dexamethasone might reduce postoperative pain in adults. We evaluated whether a caudal block of 0.1 mg kg(-1) dexamethasone combined with ropivacaine improves analgesic efficacy in children undergoing day-case orchiopexy.

METHODS

This randomized, double-blind study included 80 children aged 6 months to 5 yr who underwent day-case, unilateral orchiopexy. Patients received either 1.5 ml kg(-1) of 0.15% ropivacaine (Group C) or 1.5 ml kg(-1) of 0.15% ropivacaine in which dexamethasone of 0.1 mg kg(-1) was mixed (Group D) for caudal analgesia. Postoperative pain scores, rescue analgesic consumption, and side-effects were evaluated 48 h after operation.

RESULTS

Postoperative pain scores at 6 and 24 h post-surgery were significantly lower in Group D than in Group C. Furthermore, the number of subjects who remained pain free up to 48 h after operation was significantly greater in Group D [19 of 38 (50%)] than in Group C [four of 37 (10.8%); P<0.001]. The number of subjects who received oral analgesic was significantly lower in Group D [11 of 38 (28.9%)] than in Group C [20 of 37 (54.1%); P=0.027]. Time to first oral analgesic administration after surgery was also significantly longer in Group D than in Group C (P=0.014). Adverse events after surgery including vomiting, fever, wound infection, and wound dehiscence were comparable between the two groups.

CONCLUSIONS

The addition of dexamethasone 0.1 mg kg(-1) to ropivacaine for caudal block can significantly improve analgesic efficacy in children undergoing orchiopexy. Clinical trial registration NCT01604915.

Bayesian enhanced meta-analysis of post-operative analgesic efficacy of additives for caudal analgesia in children

BACKGROUND

The authors calculated the effect size for post-operative analgesia of three additives, clonidine, neostigmine, and tramadol to bupivacaine, ropivacaine, or levobupivacaine used for single-dose caudal extradural blockade in children.

METHODS

A meta-analysis was performed for three end points of efficacy: the increase of time until administration of analgesic drugs, the proportion of patients requiring analgesic drugs during the initial 24 post-operative hours, and the amounts of post-operative analgesic drugs. A Bayesian inference supporting direct statements about the probability of the magnitude of an effect was used to compare the effects size.

RESULTS

Neostigmine increased the duration of analgesia by 9.96 h (95% confidence interval: 7.75 to 12.16), as compared with 3.68 h (2.65 to 4.7) with clonidine and 4.45 (2.84 to 6.07) with tramadol. There is a 95% probability that neostigmine increases the duration of post-operative analgesia by more than 8 h, clonidine by more than 2.8 h, and tramadol by more than 3.25 h, as compared with local anesthetics alone. The odds ratios for the proportion of patients requiring analgesic drugs were 0.22 [0.13 to 0.37] for clonidine and 0.28 [0.10 to 0.75] for neostigmine. With tramadol, there was no statistically significant difference. All three additives reduced the amounts of post-operative analgesic drugs. Neostigmine and tramadol increase the probability for post-operative nausea or vomiting (PONV).

CONCLUSIONS

Neostigmine provides the longest post-operative analgesia. With clonidine, the duration of analgesia is shorter and sedation is increased, but the probability for PONV could be decreased.

Comparison of pre- vs. post-incisional caudal bupivacaine for postoperative analgesia in unilateral pediatric herniorrhaphy: A double-blind randomized clinical trial

Introduction:

This study was designed to evaluate the pre- vs. post-incisional analgesic efficacy of bupivacaine administered caudally in children undergoing unilateral hernia repair.

Methods:

Fifty children aged 6 months to 6 years were included in the study. Children were divided blindly between the two groups to receive pre- vs. post-incisional caudal bupivacaine. The preincisional group received 1 ml/kg of 0.125% bupivacaine caudally after induction of anesthesia and the postincisional group received the same dose caudally at the end of surgery. Heart rate, SaO₂, end tidal CO₂, and noninvasive arterial blood pressure were recorded every 10 min. The duration of surgery, extubation time, and duration of recovery period were also recorded. The pain scores were measured with using an Oucher chart in the recovery room, 2, 4, 6, 12, and 24 h after surgery. Time to first analgesia, numbers of supplementary analgesics required by each child in a 24-h period and total analgesic consumptions were recorded. Any local and systemic complications were recorded. Quantitative data were compared using a two-tailed t-test. Sex distribution and frequency of acetaminophen consumption were measured using χ² test. P < 0.05 was considered statistically significant.

Results:

The Oucher pain scale at 4, 6, 12, and 24 h after surgery, the total analgesic consumption and the numbers of demand for supplemental acetaminophen were lower statistically in preincisional group (P < 0.05). Extubation time and duration were higher in preincisional group (P < 0.05). Mean changes of heart rates were statistically lower during the anesthesia period and recovery time in preincisional group (P < 0.05).

Conclusion:

Preincisional caudal analgesia with a single injection of 0.125% bupivacaine is more effective than the postincisional one for postoperative pain relief and analgesic consumption in unilateral pediatric herniorrhaphy.

Optimal dose of propofol for intubation after sevoflurane inhalation without neuromuscular blocking agent in children

BACKGROUND

This study was designed to determine the optimal dose of propofol for excellent intubating conditions in children without neuromuscular blockade at various alveolar concentrations of sevoflurane.

METHODS

Sixty-three children, aged 0.5-5 years, were randomized to three groups of end-tidal sevoflurane concentration (ETsevo) 3%, 3.5%, and 4%. Inhalation anesthesia was started with sevoflurane 7% in 100% oxygen. When the patients became unconscious, inspired concentration was adjusted to obtain the target ETsevo for each group. When ETsevo reached the target concentration, a predetermined dose of propofol was given and tracheal intubation was performed. The proper dose of propofol was determined using the 'up-and-down' method.

RESULTS

The median dose (95% confidence intervals) of propofol for excellent tracheal intubating conditions in 50% of children were 1.25 mg/kg (0.84-1.75) at ETsevo of 3%, 0.76 mg/kg (0.35-1.21) at 3.5%, and 0.47 mg/kg (0.26-1.09) at 4%. The frequency of adverse effects was not different between groups during induction and recovery.

CONCLUSION

Propofol 1.5-2 mg/kg provides excellent intubating conditions at 3-4% ETsevo in children without using any neuromuscular blocking agent.

Segmental distribution of high-volume caudal anesthesia in neonates, infants, and toddlers as assessed by ultrasonography

BACKGROUND

The aim of this prospective, age-stratified, observational study was to determine the cranial extent of spread of a large volume (1.5 ml·kg(-1) , ropivacaine 0.2%), single-shot caudal epidural injection using real-time ultrasonography.

METHODS

Fifty ASA I-III children were included in the study, stratified in three age groups; neonates, infants (1-12 months), and toddlers (1-4 years). The caudal blocks were performed during ultrasonographic observation of the spread of local anesthetic (LA) in the epidural space.

RESULTS

A significant inverse relationship was found between age, weight, and height, and the maximal cranial level reached by 1.5 ml·kg(-1) of LA. In neonates, 93% of the blocks reached a cranial level of ≥Th12 vs 73% and 25% in infants and toddlers, respectively. Based on our data, a predictive equation of segmental spread was generated: Dose (ml/spinal segment) = 0.1539·(BW in kg)-0.0937.

CONCLUSIONS

This study found an inverse relationship between age, weight, and height and the number of segments covered by a caudal injection of 1.5 ml·kg(-1) of ropivacaine 0.2% in children 0-4 years of age. However, the cranial spread of local anesthetics within the spinal canal as assessed by immediate ultrasound visualization was found to be in poor agreement with previously published predictive equations that are based on actual cutaneous dermatomal testing.

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.

Ketorolac or fentanyl continuous infusion for post-operative analgesia in children undergoing ureteroneocystostomy

BACKGROUND

children undergoing ureteroneocystostomy suffer from post-operative pain due to the surgical incision and bladder spasm. A single-shot caudal block is a common technique for paediatric analgesia, but a disadvantage is the limitation of a short duration in spite of the additives co-administered. A few clinical trials have shown that ketorolac provides an effective post-operative analgesia and reduces the bladder spasms after ureteral implantation in children. We compared the efficacy of a continuous infusion of ketorolac and fentanyl in post-operative analgesia and bladder spasm in children who underwent ureteroneocystostomy.

METHODS

fifty-two children were allocated to the ketorolac group (Group K, n=26) and fentanyl group (Group F, n=26). After general anaesthesia, a caudal block was performed with 1.5 ml/kg of 0.15% ropivacaine. At the beginning of surgery, an infusion was started after the bolus injection of ketorolac 0.5 mg/kg or fentanyl 1 microg/kg. An infusion device was programmed to deliver ketorolac 83.3 microg/kg/h or fentanyl 0.17 microg/kg/h for 48 h.

RESULTS

two of Group F and three of Group K were excluded from the study. Post-operative pain scores were similar between the two groups. One of Group K (4%) and seven of Group F (30.4%) experienced bladder spasms. The rescue analgesic requirements were significantly less in Group K.

CONCLUSIONS

a Continuous infusion of ketorolac provided effective analgesia after operation in children who underwent ureteroneocystostomy as well as a low dosage of fentanyl. Ketorolac was more effective in reducing the frequency of bladder spasms and rescue analgesic requirements.

The effect of volume of local anesthetic on the anatomic spread of caudal block in children aged 1-7 years

OBJECTIVES

To examine the anatomic spread of caudal local anesthetic solution in children aged 1-7 years.

AIM

To determine whether incremental increases in the volume of caudal injections of 0.5, 0.75, and 1.0 ml·kg(-1) result in reliable (>90%) and potentially clinically significant increases in the number of vertebral segments reached.

BACKGROUND

Caudal block is one of the most frequently performed pediatric regional analgesic techniques. Traditional formulae suggest that changes in the volume of caudal injectate in the range 0.5-1.0 ml·kg(-1) would have clinically useful effects.

METHODS

In a single blind design, 45 children aged 1-7 years undergoing caudal block received one of the three predetermined volumes (0.5, 0.75, and 1 ml·kg(-1) ) of local anesthetic solution containing radio-opaque contrast under controlled conditions. Following X-ray examination, the anatomic spread of the block was reported by a radiologist blinded to the volume of solution received.

RESULTS

There were 15 children in each group, and they were similar in terms of age, height, and weight. Spread was observed between the 5th lumbar (L5) and 12th thoracic (T12) vertebral levels. A volume of 1 ml·kg(-1) results in a small but significantly greater spread of solution than 0.5 ml·kg(-1) (P < 0.05), but there was no difference between 0.5 and 0.75 ml or between 0.75 and 1.0 ml. No volume reliably reached a level higher than the second lumbar vertebra (L2).

CONCLUSIONS

Incrementally increasing the volume of injectate between 0.5 and 1.0 results in a modest increase in the spread of the caudal solution. It is unlikely that volumes of <1 ml will reliably reach a vertebral level that is higher than L2.

Acute pain management in children

The greatest advance in pediatric pain medicine is the recognition that untreated pain is a significant cause of morbidity and even mortality after surgical trauma. Accurate assessment of pain in different age groups and the effective treatment of postoperative pain is constantly being refined; with newer drugs being used alone or in combination with other drugs continues to be explored. Several advances in developmental neurobiology and pharmacology, knowledge of new analgesics and newer applications of old analgesics in the last two decades have helped the pediatric anesthesiologist in managing pain in children more efficiently. The latter include administering opioids via the skin and nasal mucosa and their addition into the neuraxial local anesthetics. Systemic opioids, nonsteroidal anti-inflammatory agents and regional analgesics alone or combined with additives are currently used to provide effective postoperative analgesia. These modalities are best utilized when combined as a multimodal approach to treat acute pain in the perioperative setting. The development of receptor specific drugs that can produce pain relief without the untoward side effects of respiratory depression will hasten the recovery and discharge of children after surgery. This review focuses on the overview of acute pain management in children, with an emphasis on pharmacological and regional anesthesia in achieving this goal.