Ultrasound-guided caudal anaesthesia combined with epidural anaesthesia for caesarean section: a randomized controlled clinical trial.

BACKGROUND: Although epidural anaesthesia and spinal anaesthesia are currently the general choices for patients undergoing caesarean section, these two neuraxial anaesthesia methods still have drawbacks. Caudal anaesthesia has been considered to be more appropriate for gynaecological surgery. The purpose of this study was to compare epidural anaesthesia combined with caudal anaesthesia, spinal anaesthesia and single-space epidural anaesthesia for caesarean section with respect to postoperative comfort and intraoperative anaesthesia quality. METHODS: In this clinical trial, 150 patients undergoing elective caesarean section were recruited and randomized into three groups according to a ratio of 1:1:1to receive epidural anaesthesia only, spinal anaesthesia only or epidural anaesthesia combined with caudal anaesthesia. The primary outcome was postoperative comfort in the three groups. Secondary outcomes included intraoperative anaesthesia quality and the incidences of nausea, vomiting, postdural puncture headache, maternal bradycardia, or hypotension. RESULTS: More patients were satisfied with the intraoperative anaesthesia quality in the EAC group than in the EA group (P = 0.001). The obstetrician was more significantly satisfied with the intraoperative anaesthesia quality in the SA and EAC groups than in the EA group (P = 0.004 and 0.020, respectively). The parturients felt more comfortable after surgery in the EA and EAC groups (P = 0.007). The incidence of maternal hypotension during caesarean section was higher in the SA group than in the EA and EAC groups (P = 0.001 and 0.019, respectively). CONCLUSIONS: Epidural anaesthesia combined with caudal anaesthesia may be a better choice for elective caesarean section. Compared with epidural anaesthesia and spinal anaesthesia, it has a higher quality of postoperative comfort and intraoperative anaesthesia.

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.

EEG response to a high volume (1.5 mL/kg) caudal block in infants less than 3 months.

INTRODUCTION: The substantial compression of the dural sac and the subsequent cranial shift of cerebrospinal fluid caused by a high-volume caudal block has been shown to significantly but transiently reduce cerebral blood flow. The aim of the present study was to determine whether this reduction in cerebral perfusion is significant enough to alter brain function, as assessed by electroencephalography (EEG). METHODS: Following ethics approval and parental informed consent, 11 infants (0-3 months) scheduled to undergo inguinal hernia repair were included in the study. EEG electrodes (using nine electrodes according to the 10-20 standard) were applied following anesthesia induction. Following a 5 min baseline period, a caudal block was performed (1.5 mL/kg), whereafter the EEG, hemodynamic, and cerebral near-infrared spectroscopy responses were followed during a 20 min observation period that was divided into four 5 min segments. Special attention was given to alterations in delta power activity since this may indicate cerebral ischemia. RESULTS: All 11 infants displayed transient EEG changes, mainly represented by increased relative delta power, during the initial 5-10 min postinjection. The observed changes had returned close to baseline values 15 min postinjection. Heart rate and blood pressure remained stable throughout the study. CONCLUSION: A high-volume caudal block appears to increase intracranial pressure, thereby reducing cerebral blood flow, to the extent that it transiently will affect cerebral function as assessed by EEG (increased delta power activity) in approximately 90% of small infants. TRIAL REGISTRATION NUMBER: ACTRN12620000420943.

Awake caudal anesthesia in ex-premature infants undergoing lower abdominal surgery: A narrative review.

BACKGROUND AND OBJECTIVES: The aim of this narrative review is to evaluate the literature describing the use of caudal anesthetic-based techniques in premature and ex-premature infants undergoing lower abdominal surgery. METHODS: All available literature from inception to August 2023 was retrieved according to Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines from Medline, PubMed, Embase, and the Cochrane Library. Two authors reviewed all references for eligibility, abstracted data, and appraised quality. RESULTS: Of the 211 articles identified, 45 met our inclusion criteria yielding 1548 cases with awake caudal anesthesia. The review included 558 (36.0%) cases of awake caudal anesthesia, 837 cases (54.1%) of "awake" caudal anesthesia with sedation, and 153 cases (9.9%) of combined spinal caudal epidural anesthesia without sedation. The overall anesthetic failure rate was 7.2% (71.9:1000 caudals). Failure rates were highest for CSEA (13.7%, 7.7-18.4), intermediate for awake caudal (6.6%, 5.26-9.51), and lowest for sedated caudal anesthesia (5.85%, 4.48-7.82). The incidence (range) of perioperative apnea was highest for sedated caudal anesthesia (8.16, 0%-24%), intermediate for awake caudal (7.62%, 0%-60%), and lowest for CSEA (5.53%, 0%-14.3%). High spinal anesthesia occurred in 0.84%, or 8.35:1000 caudals overall. The incidence was highest in awake caudal anesthesia cases (1.97% or 19.7:1000 caudals), intermediate with caudal with sedation (1.07% or 10.7:1000 caudals), and lowest in CSEA (0.7% or 6.6:1000 caudals). Our review was confounded by incomplete data reporting and small sample sizes as most were case reports. There were no high-quality randomized controlled trials, and the eight single-center retrospective data reviews lacked sufficient data to perform meta-analysis. CONCLUSIONS: There is insufficient evidence to validate or refute the benefits of the use of "awake" caudal anesthesia in premature and ex-premature infants. The high doses of local anesthetics used, the high failure rate, and the increased incidence of high spinal anesthesia would suggest that the techniques offer no real advantages over awake spinal anesthesia or general anesthesia with a regional block.

Preemptive caudal anesthesia on back pain after lumbar discectomy: a randomized and controlled study.

OBJECTIVE: In this randomized and prospective research, we aimed to relieve surgical and muscle-related pain early after lumbar disc operations with caudal preemptive analgesia. MATERIALS AND METHODS: A total of 120 patients with single-level lumbar disc herniation were included in this study. The caudal epidural injection was performed for all patients 20 min before surgery. The patients were divided into three groups. Non-steroidal anti-inflammatory drugs or tramadol use were recorded. Pre-operative and post-operative pain was interpreted through a visual analog scale. RESULTS: There was a difference between the groups in all post-operative measurements (p < 0.05), between Group 1 and Group 3, and between Group 2 and Group 3. A statistical significance has been achieved between the groups at the 1st h, 2nd h, 4th h, and 24th h (p < 0.05). The difference between the pain intensities of the patients at the 24th h and the 1st week was statistically significant in Groups 1 and 2 (p < 0.05). Evaluation of the effects of medical treatments reduced the severity of back pain and foot pain. CONCLUSION: The preemptive bupivacaine or in combination with methylprednisolone caudal injection is an effective and safe method to reduce post-operative pain and ameliorate functional capacity for the treatment of lumbar disc herniation.

OBJETIVO: En esta investigación prospectiva aleatorizada, nuestro objetivo fue aliviar el dolor quirúrgico y muscular temprano después de las operaciones de disco lumbar con analgesia preventiva caudal. MATERIALES Y MÉTODOS: en este estudio se incluyeron un total de 120 pacientes con hernia de disco lumbar de un solo nivel. La inyección epidural caudal se realizó para todos los pacientes 20 minutos antes de la cirugía. Los pacientes fueron divididos en tres grupos. Se registró el uso de AINE o tramadol. El dolor preoperatorio y postoperatorio se interpretó a través de una escala analógica visual. RESULTADOS: Hubo diferencia entre los grupos en todas las medidas postoperatorias (p < 0.05), entre el grupo 1 y el grupo 3, y entre el grupo 2 y el grupo 3. Se ha logrado una significación estadística entre los grupos a la 1a hora, 2a hora, 4 y 24 horas (p < 0.05). La diferencia entre las intensidades de dolor de los pacientes a la hora 24 y la primera semana fue estadísticamente significativa en los Grupos 1 y 2 (p < 0.05). La evaluación de los efectos de los tratamientos médicos redujo la gravedad del dolor de espalda y de pie. CONCLUSIÓN: La bupivacaína preventiva, o en combinación con la inyección caudal de metilprednisolona, es un método eficaz y seguro para reducir el dolor posoperatorio y mejorar la capacidad funcional para el tratamiento de la hernia de disco lumbar.

Sex differences in pediatric caudal epidural anesthesia under sedation without primary airway instrumentation.

STUDY OBJECTIVE: To identify sex differences associated with caudal epidurals, the most commonly used technique of pediatric regional anesthesia, based on individually validated data of ultrasound-guided blocks performed between 04/2014 and 12/2020. METHODS: Prospectively collected and individually validated data of a cohort of children aged between 0-15 years was analyzed in a retrospective observational study. We included pediatric surgeries involving a primary plan of caudal epidural anesthesia under sedation (without airway instrumentation) and a contingency plan of general anesthesia. Sex-specific rates were analyzed for overall failure of the primary anesthesia plan, for residual pain, for block-related technical complications and for critical respiratory events. We used Fisher´s exact tests and multivariable logistic regressions were used to evaluate sex-specific associations. RESULTS: Data from 487 girls and 2060 boys ≤15 years old (ASA status 1 to 4) were analyzed. The primary-anesthesia-plan failure rate was 5.5% (95%CI 3.8%-7.8%) (N = 27/487) among girls and 4.7% (95%CI 3.9%-5.7%) (N = 97/2060) among boys (p = 0.41). Residual pain was the main cause of failure, with rates of 4.5% (95%CI 2.9-6.6%) (N = 22/487) among girls and 3.0% (95%CI 2.3-3.8%) (N = 61/2060) among boys (p = 0.089). Block-related technical complications were seen at rates of 0.8% (95%CI 0.3%-1.9%) (N = 4/487) among girls vs 2.5% (95%CI 0.5-2.7%) (N = 51/2060) among boys and, hence, significantly more often among male patients (p = 0.023). Male sex was significantly associated with higher odds (adjusted OR: 3.18; 95% CI: 1.12-9; p = 0.029) for such technical complications regardless of age, ASA status, gestational week at birth or puncture attempts. Critical respiratory events occurred at a 1.7% (95%CI 1.2%-2.3%) rate (N = 35/2060) twice as high among boys as 0.8% (95%CI 0.3%-1.9%) (N = 4/487) among girls (p = 0.21). CONCLUSIONS: While the the primary-anesthesia-plan failure rate was equal for girls and boys, technical complications and respiratory events are more likely to occur in boys.

Caudal anesthesia is not associated with post-operative complications following distal hypospadias repair.

INTRODUCTION: The use of caudal anesthesia at the time of hypospadias repair remains controversial as some prior studies have reported increased postoperative complication rates associated with caudal nerve block. However, these results have been called into question due to confounding factors and heterogeneous study groups. OBJECTIVE: Given the importance of identifying true risk factors associated with increased hypospadias complication rate, we examined our experience with caudal anesthesia limiting our analysis to distal repairs. We hypothesized that caudal anesthesia would not be associated with increased postoperative complications. STUDY DESIGN: We retrospectively reviewed our institutional hypospadias database from June 2007 to January 2021. All boys who underwent single-stage distal hypospadias repair with either caudal or penile block with minimum 1 month follow up were included. Records were reviewed to determine the type of local anesthesia, type of hypospadias repair, all complications, and time to complication. Association between any complication and local anesthesia type was evaluated by univariate and multivariate logistic regression analysis controlling for age at surgery and type of repair. A sub-analysis was performed for complications occurring ≤30 days. RESULTS: Overall, 1008 boys, 832 (82.5%) who received caudal and 176 (17.5%) penile block, were included. Median age at surgery was 8.1 months and median follow up was 13 months. Overall complication rate was 16.4% with 13.8% of patients requiring repeat operation. Median time to complication was 10.59 months and was significantly shorter in the caudal group (8.45 vs. 25.2 months). Caudal anesthesia was associated with higher likelihood of complication on univariate analysis; however, this was not true on multivariate analysis when controlling for age and type of repair. Caudal anesthesia was not associated with increased likelihood of complication within 30 days. DISCUSSION: Since the association between caudal anesthesia and hypospadias complications was first suggested, several studies have tried to answer this question with variable results. Our findings add to the evidence that there is no association between caudal anesthesia and increased hypospadias complications in either the short or long term. The major strengths of our study are a large, homogenous study population, robust follow up and inclusion of data from 14 surgeons over 14 years. Limitations include the study's retrospective nature as well as lack of standardized follow up protocol throughout the study period. CONCLUSIONS: After controlling for possible confounders, caudal nerve block was not associated with increased risk of postoperative complications following distal hypospadias repair.

A comparison of operative and anesthetic techniques for inguinal hernia repair in infants.

BACKGROUND: Pediatric inguinal hernia repair (IHR) is increasingly performed using minimally invasive surgery (MIS) but has only recently been described using caudal block without endotracheal intubation. We evaluated the surgical outcomes and resource utilization of infants undergoing hernia repair, comparing both the operative approach (open/MIS) and anesthetic technique (general anesthesia [GA]/caudal). METHODS: All infants <1 year-of-age undergoing elective IHR without concomitant procedures from July 2016 to July 2021 at a single tertiary care teaching center were retrospectively reviewed. Eight surgeons and 25 anesthesiologists contributed patients, with approach dictated by practitioner preference. Data collected included patient demographics, surgical and anesthetic details, and operating room (OR) utilization metrics. Post-operative complications were evaluated and aggregated, including recurrent hernia, metachronous hernia, hematoma, hydrocele, testicular atrophy, and acquired cryptorchidism. Descriptive statistics were performed with R Studios (p < 0.05). RESULTS: Of the 338 patients included for analysis, most underwent an open procedure (n = 275) while anesthetic technique was evenly split between GA (n = 185) and caudal (n = 153). Most patients were male (87.6%) and born premature: mean gestational age of 31.4 ± 4.1 weeks. MIS-to-Open conversion was noted once (3.3%) in the GA MIS group, but none in caudal. Median follow up was 2.5 (1.4-3.8) years. No differences were noted in aggregate surgical complication rates (p = 0.4). The Caudal Open group had the shortest total OR time (p < 0.01); caudal anesthesia shortened post-procedure times (p < 0.01). CONCLUSION: MIS IHR performed under caudal block and sedation yields comparable complication rates compared to the open approach or GA. Open IHR with caudal blockade was the most efficient operative room utilization. TYPE OF STUDY: Original Article, Clinical Research. LEVELS OF EVIDENCE: Level III.

Morphological and morphometric features of sacral hiatus and its clinical significance in caudal epidural anaesthesia.

BACKGROUND: Caudal epidural block (CEB) failure or complications are not unheard even among experienced anaesthesiologists and are usually due to sacral hiatus (SH) anatomy variations. The aim of the present study is to observe, record and analyse important anatomical features of SH and correlate them with potential CEB limitations. MATERIALS AND METHODS: The SH of 155 complete and undamaged Greek adult dry sacra of known sex were included in the study. Three non-metric (shape of SH and location of hiatal apex and base in relation to level of sacral/coccygeal vertebra) and five metric parameters (height of the SH, transverse width of the SH at the base, anteroposterior diameter of the SH at the level of its apex and the distance from the sacral apex and base to the upper border of S2 foramina) were evaluated. RESULTS: Inverted U (34.83%) and inverted V (26.45%) were the commonest shapes. Hiatal apex and base were most commonly related to the level of S4 (78.70%) and S5 vertebra (89.03%), respectively. Mean height, depth and intercornual distance were 19.05 ± 8.65 mm, 5.39 ± 1.84 mm and 12.41 ± 3.16 mm, respectively, whereas mean distance between the upper border of S2 foramen and the apex and base of the SH were 46.34 mm and 63.48 mm, respectively. Anatomical variations of SH that might be responsible for CEB failure, such as elongated SH, absence of SH, complete dorsal wall agenesis of sacral canal and narrowing (< 3 mm) at the apex of SH were found in 17.43% of sacra (male 10.94% and female 25.22%). CONCLUSIONS: This study suggests a potential risk of failure of CEB in Greek patients, especially in females, which should be kept in mind while giving caudal epidural anaesthesia.

Laparoscopic versus Open Inguinal Hernia Repair Is Feasible in Infants with Caudal Anesthesia and Spontaneous Respiration.

INTRODUCTION: Minimally invasive surgery (i.e., laparoscopy) and minimally invasive anesthesia (i.e., caudal anesthesia with spontaneous respiration) have separately shown benefits for inguinal hernia repair in infants, yet to what degree these techniques can be combined remains unknown. This study investigated whether laparoscopy impacts the feasibility of performing caudal anesthesia with spontaneous respiration in infants. METHODS: Prospectively collected data of all infants less than 12 months old and over 3 kg weight who underwent laparoscopic indirect hernia repair (LAP) at our department from 2019 to 2021 were compared with a historical control-matched group of infants who underwent open repair (OPEN) from 2017 to 2021. We assessed the patients' characteristics, anesthesia, and surgical data as well as intra- and postoperative complications. RESULTS: A total of 87 infants were included (LAP n = 29, OPEN n = 58). Caudal anesthesia with spontaneous respiration was feasible in 62.1% of cases (LAP n = 55.2%, OPEN n = 65.5%; nonsignificant). Neither group registered anesthetic intra- or postoperative complications. Sedatives were utilized in 97% of LAP patients versus 56.9% of OPEN patients (p < 0.00001). The airway was secured with a laryngeal mask in 89.7% of patients during LAP versus 41.4% during OPEN (p < 0.00001). No significant differences were found regarding the use frequency of opioids (48.3% LAP vs. 34.5% OPEN; nonsignificant) or neuromuscular blockers (6.9% LAP vs. 5.2% OPEN; nonsignificant). CONCLUSION: This is the first comparative study on caudal anesthesia and spontaneous respiration in infants undergoing laparoscopic versus open inguinal hernia surgery. Laparoscopy increased the need for ventilatory support and sedatives but did not significantly impair the feasibility of caudal anesthesia and spontaneous respiration.

[Caudal Anesthesia: Overview and Practical Recommendations]. / Kaudalanästhesie: Übersicht und praktische Handlungsempfehlungen.

Caudal anesthesia is one of the most commonly performed forms of regional anesthesia in childhood, which is relatively easy to learn and very effective. Indications for sacral block are all interventions below the costal arch. The puncture can be performed on premature babies and children up to 50 kg body weight. The use of ultrasound increases the success rate and verifies the epidural injection. Bupivacaine and ropivacaine can be combined with adjuvants such as clonidine, morphine or ketamine, which lead to a prolonged effect. In selected patient groups, the operation can also be performed under caudal anesthesia with sedation in order to maintain spontaneous breathing and avoid respiratory complications. This review article gives an overview of caudal anesthesia and offers practical instructions for blocks during general anesthesia and sedation.

Levobupivacaine plasma concentrations following repeat caudal anesthetics.

AIM: A single caudal anesthetic at the start of lower abdominal surgery is unlikely to provide prolonged analgesia. A second caudal at the end of the procedure extends the analgesia duration but total plasma concentrations may be associated with toxicity. Our aim was to measure total plasma levobupivacaine concentrations after repeat caudal anesthesia in infants and to generate a pharmacokinetic model for prediction of plasma concentrations after repeat caudal anesthesia in neonates, infants and children. METHODS: Infants undergoing definitive repair of anorectal malformations or Hirschsprung's disease received a second caudal anesthesia at the end of the procedure. Total levobupivacaine concentrations were assayed 3-4 times in the first 6 h after the initial caudal. These data were pooled with data from four studies describing plasma concentrations after levobupivacaine caudal or spinal anesthesia. Population pharmacokinetic parameters were estimated using nonlinear mixed-effects models. Covariates included postmenstrual age and body weight. Parameter estimates were used to simulate concentrations after a repeat levobupivacaine 2.5 mg kg-1 caudal at 3 or 4 h following an initial levobupivacaine 2.5 mg kg-1 caudal. RESULTS: Twenty-one infants (postnatal age 11-32 weeks, gestation 37-39 weeks, weight 5.2-8.6 kg) were included. The measured peak plasma concentration after repeat caudal levobupivacaine 2.5 mg kg-1 4 h after initial caudal was 1.38 mg L-1 (95% prediction interval 0.60-2.6 mg L-1 ) and 3 h after initial caudal was 1.46 mg L-1 (0.60-2.80) mg L-1 . Simulation of total plasma concentrations in neonates (7 kg, 57 weeks postmenstrual age) given caudal levobupivacaine 4 h after the initial caudal were 1.76 mg L-1 (0.68-3.50) mg L-1 if 2.5 mg kg-1 levobupivacaine was used and 0.88 mg L-1 (0.34-1.73) mg L-1 if 1.25 mg kg-1 of 0.125% levobupivacaine was used. In simulated older children (20 kg, 6 years), the mean maximum concentration was 1.43 mg L-1 (0.60-2.70) mg L-1 if 2.5 mg kg-1 levobupivacaine was repeated at 3 h. CONCLUSION: Repeat caudal levobupivacaine 2.5 mg kg-1 at 3 h after an initial 2.5 mg kg-1 dose does not exceed the concentration associated with systemic local anesthetic toxicity. In 2.5% of simulated neonates (weight 3.8 kg, PMA 40 weeks), repeat caudal anesthesia demonstrates broaching of the lower concentration limit associated with toxicity at both 3 and 4 h after initial caudal.

Elimination of Postoperative Narcotics in Infant Robotic Pyeloplasty Using Caudal Anesthesia and a Non-Narcotic Pain Pathway.

Introduction: Research suggests that narcotic pain medications are dramatically overprescribed. We hypothesize that narcotics are unnecessary for postoperative pain control in most infants undergoing robotic pyeloplasty. In this series, we report our experience combining caudal blocks with a non-narcotic postoperative pathway as a means of eliminating postoperative narcotics after infant robotic pyeloplasty. Methods: We reviewed 24 consecutive patients who underwent robotic pyeloplasty by a single surgeon treated with an end-procedure caudal block followed by a non-narcotic postoperative pain pathway treated between May 2017 and May 2021. The standardized postoperative pathway consisted of an end-procedure caudal block followed by alternating intravenous acetaminophen and ketorolac. We reviewed demographics, outcomes, and unscheduled health care encounters within 30 postoperative days. Results: Sixty-three percent (15/24) of patients were male and average age was 12.1 months (range 4-34 months). Fifty-eight percent (9/15) underwent surgery on the left, and 16.7% (4/24) of patients received a single postoperative dose of narcotics in the postanesthesia care unit. No patient required narcotic prescriptions at discharge or anytime thereafter. The average length of stay was 1.13 days. There was no pain-related unscheduled visits or phone calls after discharge. Conclusions: This series shows that a non-narcotic standardized pain management strategy is a viable option for infants undergoing robotic pyeloplasty. Postprocedure caudal block is a good addition to a non-narcotic pathway. In the future, we intend to expand these findings to other pediatric urologic procedures in the hope of eliminating unnecessary narcotic use.

Ultrasound determination of the dural sac to sacrococcygeal membrane distance in premature neonates.

BACKGROUND: Caudal epidural analgesia is the most common regional anesthetic performed in infants. Dural puncture, the most common serious complication, is inversely proportional to age. Measuring the distance from the sacrococcygeal membrane to the dural sac may prevent dural puncture. This study measures the sacrococcygeal membrane to dural sac distance using ultrasound imaging to determine feasibility of imaging and obtaining measurements. METHODS: Sacral ultrasound imaging of 40 preterm neonates was obtained in left lateral decubitus, a typical position for caudal blockade. No punctures were made. The sacrococcygeal membrane and termination of the dural sac were visualized, and the distance measured. The spinal levels of the conus medullaris and dural sac termination were recorded. RESULTS: 20 males and 20 females former preterm neonates with an average weight (SD; range) of 1740 (290; 860-2350) g and average age (SD; range) of 35.0 (1.35; 32.2-39) weeks gestational age at the time of imaging. The average sacrococcygeal membrane to distal dural sac distance (SD; range) was 17.4 (3.1; 10.6-26.3) mm. Overall, the weights correlated positively with the distance but the coefficient of variation was large at 23%. The conus medularis terminated below the L3 level and dural sac below the S3 level in 20% and 10% of subjects respectively with hip flexion. CONCLUSION: Ultrasound can be used to measure the sacrococcygeal membrane to dura distance in preterm neonates prior to needle insertion when performing caudal block and demonstrates large variability. Ultrasound imaging may identify patients at risk for dural puncture. When ultrasound is not available, needle insertion less than 3 mm/kg beyond the puncture of the sacrococcygeal membrane should prevent dural contact in 99.9% of neonates.

The effect of caudal epidural block on the surgical complications of hypospadias repair in children aged 6 to 35 months: A randomized controlled trial.

BACKGROUND: Caudal epidural block (CEB) in hypospadias surgery has the benefit of reducing post-operative pain and possibly intra-operative bleeding. Some studies, however, have suggested that this technique may increase the rate of post-operative complications. Considering the uncertainty about the effect of CEB on surgical complications of hypospadias repair, the current study was performed. OBJECTIVE: The aim of this randomized clinical trial was to compare the complication rates between patients who receive CEB after hypospadias surgery and those who did not. STUDY DESIGN: This double-blind randomized controlled trial was conducted on boys aged 6-35 months, who underwent hypospadias repair surgery in a university hospital from March 2018 to March 2019. Sixty patients were randomly divided into two groups (group A: 31 and group B: 29). In group B, CEB was performed, using 0.5 mg/kg of 0.125% bupivacaine (Marcaine). Postoperative complications including fistula, meatal stenosis, dehiscence, and occurrence of bleeding were assessed during six months after surgery. RESULTS: The patients were assessed for possible complications at 24 h, one week, one, three and six months after surgery. No remarkable differences were observed between the patients in the two groups in terms of the frequency of dehiscence, fistula, and meatal stenosis (P > 0.05). Moreover, the difference in complication rates between the patients with proximal and distal hypospadias did not reach statistical significance (P = 0.549). DISCUSSION: Assessment of complications showed no significant difference between the two study groups in terms of dehiscence, fistula, and meatal stenosis (Clavien type III). In addition, complication rate was not significantly different according to severity of hypospadias between the two groups. Our study had limitations such as short follow up and small sample size, which resulted in insignificant difference in complication rate between proximal and distal hypospadias. These limitations request large studies with long term follow up. CONCLUSION: The current study showed that the use of caudal block anesthesia in comparison with general anesthesia did not increase surgical complications, which approved CEB protocol as a safe method in hypospadias repair.

Subanesthetic intravenous ketamine vs. caudal bupivacaine for postoperative analgesia in children undergoing infra-umbilical surgeries: a non-inferiority randomized, single-blind controlled trial.

BACKGROUND: Subanesthetic intravenous (IV) ketamine acts as an analgesic and has opioid-sparing effects, particularly for acute postoperative pain; however, its effectiveness in children is understudied. The primary aim of this study was to evaluate the non-inferiority of subanesthetic IV ketamine vs. caudal bupivacaine for postoperative analgesia in children undergoing infraumbilical surgery. METHODS: Children aged < 6 years were enrolled in this single-blind study and randomized to receive either subanesthetic IV ketamine (0.3 mg/kg) or caudal 0.125% bupivacaine (1 ml/kg) along with general anesthesia. Postoperative pain was assessed using the FLACC scale at 30 minutes and 1, 2, 3, and 6 h post-operation. Intra- and postoperative opioid consumption, time to extubation, postoperative vomiting, agitation, sedation, and inflammatory markers were also assessed. RESULTS: Altogether, 141 children completed the study (ketamine group: n = 71, caudal group: n = 70) The cumulative proportion of children without significant postoperative pain (FLACC score < 4) in the first 6 h post-surgery was 45.1% in the ketamine group vs. 72.9% in the caudal group (P < 0.001). More children in the ketamine group required an additional dose of intraoperative fentanyl (33.8% vs. 5.7%, P < 0.001) and postoperative tramadol (54.9% vs. 27.1%, P < 0.001). However, postoperative agitation, sedation, and other secondary outcomes were similar between the groups. CONCLUSIONS: Subanesthetic ketamine is inferior to caudal bupivacaine for postoperative analgesia in children aged < 6 years undergoing infra-umbilical surgeries; however, other postoperative outcomes are similar.

Perioperative sedation requirements of infants aged 0 to 3 months subjected to lower-body surgery under caudal blockade: a randomized controlled trial.

BACKGROUND: It remains unclear how much sedation is required for subumbilical surgery under caudal blockade, and sedatives may carry a poorly understood risk of late sequelae in infants. We designed a randomized controlled study to evaluate total propofol consumption and perioperative sedation quality with the avoidance of continuous perioperative sedation in infants undergoing surgery under caudal anesthesia. METHODS: Thirty-two infants (age: 0-3 months) were randomized to one of two groups in which perioperative administration of propofol was provided either "as needed" or by continuous infusion (5 mg kg-1 h-1). After induction of anesthesia via a facemask with sevoflurane, a venous access was established and 1 mL kg-1 of ropivacaine 0.35% was injected for caudal anesthesia. Intraoperative stress was assessed by repeated recording comfort behavioral scale scores and heart rates. RESULTS: Significantly (P=0.0001) less propofol was administered in the as-needed group (0.7±1.4 mg/kg) than in the continuous-infusion group (3.0±1.6 mg/kg). This difference was not reflected in different requirements of additional intraoperative sedation (0.5±0.8 mg/kg in 5 versus 0.6±1.0 mg/kg in four cases; P=0.76). CONCLUSIONS: As needed propofol administration offers no disadvantage in terms of intraoperative sedation, but significant dose reductions can be achieved by avoiding continuous propofol infusion.