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 effect of combined pudendal nerve and spermatic cord block or caudal epidural block on postoperative analgesia after posterior urethroplasty: a randomized trial.

BACKGROUND: Postoperative pain management remains a significant challenge for patients undergoing posterior urethroplasty (PU). In a previous study, we proposed a novel technique of combined pudendal nerve (PN) and spermatic cord (SC) block to manage pain after PU. The present trial was conducted to test the hypothesis that this technique is effective for pain control after PU and provides longer-lasting analgesia than caudal epidural block (CB). METHODS: Sixty patients undergoing PU were randomized into two groups: Group NB received combined PN and SC block, and Group CB received CB. General anesthesia with a laryngeal mask was performed. The primary outcome was the postoperative analgesic duration, and the secondary outcomes included the Numeric Rating Scale (NRS) scores for pain and the number of patients with different motor scores of the lower limb at 3, 6, 12, and 24 h postoperatively. RESULTS: Two patients in Group CB were withdrawn due to block failure. The postoperative analgesic duration was statistically longer in Group NB compared with Group CB (mean difference [95% confidence interval], 115.78 min [17.80, 213.75]; P = 0.021). The NRS scores for pain at 12 and 24 h after surgery were statistically lower in Group NB compared with Group CB. Group NB had statistically more patients with motor score 0 at 3 h postoperatively than Group CB. CONCLUSIONS: PN combined with SC block is an effective technique for postoperative analgesia in PU. This technique can achieve a longer duration of analgesia and lower pain scores, especially 12 h after surgery, than a CB. TRIAL REGISTRATION: This study was registered in the Chinese Clinical Trial Register (registration no. ChiCTR2100042971, registration date on 2/2/2021).

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.

Comparison of Caudal Block and Sacral Erector Spina Block for Postoperative Analgesia following Pediatric Circumcision: A Double-Blind, Randomized Controlled Trial.

INTRODUCTION: Caudal block (CB) and erector spina plane block (ESPB) have been shown to provide effective postoperative analgesia following circumcision. Our aim was to compare the analgesic efficacy of sacral ESPB and CB, as well as the time to first analgesic requirement and postoperative complications. METHODS: Patients aged 1-7 years in the ASA I-II group, who were scheduled for circumcision, were included in the study. Blocks were performed under general anesthesia before the operation. Postoperative pain was evaluated using the Face, Legs, Activity, Cry, and Consolability (FLACC) scores. Analgesic requirements in the first 24 h postsurgery, the time of first analgesia requirement, and postoperative complications were recorded. RESULTS: A total number of 150 patients were included in the study. In the CB group, urinary retention was observed. No side effects were observed in the sacral ESPB group. The 4th and 6th h postoperative FLACC scores were lower in the ESP group. The number of analgesic consumption in the first 24 h postsurgery was significantly lower in the ESPB group (p < 0.001). CONCLUSION: Based on our results, sacral ESPB performed with ultrasonography is a simple and safe regional anesthesia method that can be used to provide effective postoperative analgesia for circumcision.

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.

Correlation of Block Success with Perfusion Index Measurement in Cases of Pediatric Surgery Under Caudal Epidural Block Anesthesia.

PURPOSE: One of the regional anesthetic procedures, caudal epidural block, is important for lower extremities surgeries in the pediatric patient population. The perfusion index (PI) value, which reflects vasomotor tone, can be used to indicate block success. The aim was to compare the role of perfusion index, heart rate, and mean arterial pressure in detecting the success of caudal epidural block and to investigate whether perfusion index was an earlier indicator in determining the success of the block in pediatric surgery cases. DESIGN: A randomized controlled trial. METHODS: The study included 58 patients, American Society of Anesthesiologists'classification 1, between the ages 1 and 6 years. In the left lateral decubitus posture, caudal epidural block was performed using a 23 or 25-gauge caudal needle and a dosage of 0.25% bupivacaine (1 mL/kg). At the 0, 1, 5, 7, 10, 15, and 20th minutes, peripheral oxygen saturation, heart rate, mean arterial pressure, and PI values were obtained using a probe attached to the first toe of the left foot. A successful caudal epidural block indication was defined as an increase of at least 100% in the PI value over the baseline value and a 15% decrease in mean arterial pressure and heart rate FINDINGS: PI represents the ratio of the photoplethysmography signal to pulsatile over nonpulsatile light absorbance. An increase in the PI value indicates that the block is effective. In the 20-minute follow-up period after caudal epidural block, there was at least a 100% increase in PI value in all of the patients at the seventh minute. An expected 15% reduction in mean arterial pressure was observed in 14.5% of the patients and an expected 15% reduction in heart rate was observed in 45.6% of the patients. CONCLUSIONS: The results obtained from our study show that the increase in PI values is associated with caudal epidural block success. The PI value is more rapid, sensitive and objective than those produced by other parameters. Benefits include an earlier change in anesthesia management due to block failure and faster initiation to surgery, which reduces exposure to anesthetic chemicals.

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.

[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.

The utility of ultrasonography in anesthesia management in 3 cases of caudal regression syndrome.

Caudal regression syndrome is an extremely rare clinical entity. It is a challenge to anesthesiologist due to its multisystem involvement. Regional anesthesia literature on caudal regression syndrome is scarce. We report three cases where optimal use of ultrasonography aided in providing satisfactory peri-operative pain relief. Furthermore, a cogent and a logical review of the decision-making processes for the regional blockade in children with caudal regression syndrome are presented.

Anatomical study of the human sacral hiatus and implications for successful caudal epidural injection.

BACKGROUND: Caudal epidural injection (CEI) is a commonly used procedure to treat back and leg pain secondary to nerve root irritation, predominantly in the context of spinal canal stenosis. Key to a successful outcome is correct needle placement. Although fluoroscopic guidance confirms accurate needle placement, it does not help in determining the starting point, which can lead to multiple needle insertions. OBJECTIVE: This study aimed to determine the variability in size and position of the sacral hiatus and to identify reproducible surface landmarks to locate its position. METHODS AND STUDY DESIGN: 250 human sacral bones were examined, measuring morphology and structure. Vernier callipers accurate to 0.1 mm were used for measurements. Results were analysed using SPSS statistical software. RESULTS: Two specimens were excluded due to agenesis of the hiatus (0.8%). Of the remaining 248 specimens, it was found that the mean internal diameter of the sacral hiatus was 5.12 mm (SD 1.61). The position of the hiatus was variable but was most commonly found at the level of the fourth sacral vertebrae (62.9%, n = 156). Mean distance between the two superolateral sacral prominences was 64.15 mm (SD 6.5) and between superolateral sacral prominences (left and right) and apex of the hiatus were 63.21 mm (SD 10.9) and 63.34 mm (SD 10.87) respectively. CONCLUSION: Although there is a clear anatomical variance in the position and size of the sacral hiatus, this study suggests that surface anatomy landmarks can be used to form an equilateral triangle of which the inferior apex should correspond to the sacral hiatus. Knowledge of this surface anatomy may assist the correct location of the sacral hiatus and hence subsequently improve the efficacy of CEI.

Imaging anatomy of the vertebral canal for trans-sacral hiatus puncture of the lumbar cistern.

A standard lumbar puncture may be impossible for many anatomic or technical reasons. Previous accounts of caudal epidural anesthesia and other procedures via the sacral hiatus prompted us to test if image-guided percutaneous trans-sacral hiatus access to the lumbosacral subarachnoid cistern would be anatomically feasible. To study vertebral canal morphometry and curvature, we analyzed midsagittal computed tomography-myelogram images of 40 normal subjects and digitally measured sacral curvatures between S1 to S5 and S2 to S4 using two methods whereby a lower angle signifies a straighter sacrum. We measured midsagittal vertebral canal area, hiatus width, dural sac termination levels, and distance from sacral hiatus to the dural sac tip (needle distance). Subjects were F:M = 25:15, with a mean age of 44.9 years. The two S1-S5 full sacral curvature mean angles were 57.3° and 60.4°. Almost all sacral hiatuses were at S4, and dural sac terminations were at S1-S2. The mean S2-S4 sacral curvature was 25.1°, and the mean needle distance was 57.7 mm. Using two-way analysis of variance, there were significant sex differences for needle distances (p = .001), and full and limited sacral curvatures (p = .02, and p = .046, respectively). There were no significant linear regression correlations between age and sacral curvature, needle distance, canal area, or hiatus width. Therefore, despite a frequently prominent full sacral curvature, the combination of S1-S2 dural sac termination plus a relatively straight trajectory of the lower vertebral canal between S2 and S4 support the theoretical feasibility of percutaneous trans-sacral hiatus and vertebral canal access to the lumbosacral cistern using a standard spinal needle.

Estimation of the relationship between the sacral hiatus and other dorsal sacral parameters using principle component analysis.

PURPOSE: Correct localization of the sacral hiatus is essential for administering a successful caudal epidural block. The purpose of this study is to create a statistical model of sacral hiatus from dorsal sacral parameters to improve the location of the hiatus and thus, reduce the failure rate. The aim of this investigation was to examine the relationship of sacral hiatus morphology and dimension with sacral curvature. This study further examines the dorsal sacral parameters that could affect the sacral hiatus dimension. METHODS: Adult, human, dry sacra and three-dimensionally reconstructed sacra from computed tomography imaging of normal subjects were included in the study and measured using digital Vernier calipers of 0.01 mm accuracy and Geomagic freeform plus software, respectively. RESULT: The most frequent shape of the sacral hiatus was an inverted V (48%) followed by inverted U shape (32%), an irregular shape (12.3%), an M shape (4.7) and an A shape (2.8%). The data were represented by mean and standard deviation. Sacra with M-shaped hiatus had the lowest hiatal length (14.21 ± 5.44 mm), whereas sacra with an inverted V-shaped hiatus had the highest length (25.41 ± 11.3 mm). The anteroposterior diameter of the sacral hiatus at the base in males and females was found to be 3.46 ± 1.48 mm and 2.79 ± 0.83 mm, respectively (P < 0.001). The distance between the caudal end of the median sacral crest and the apex of the sacral hiatus (7.90 ± 6.74 mm, 4.4 ± 5.86 mm) also revealed sexual dimorphism (P < 0.001). CONCLUSION: The correlations between most of the dorsal sacral parameters and length of the sacral hiatus are significant. The intercornual distance is also moderately correlated with the distance between right and left lateral sacral crest S1 level. Dorsal sacral parameters predicts variance of the sacral hiatus dimension from 40 to 73% and this could be utilized for statistical model of the sacral hiatus.

Cerebral blood flow alterations associated with high volume caudal block in infants.

BACKGROUND: High-volume (1.5 ml kg-1) caudal block in infants results in major reductions of cerebral blood flow velocity (CBFV) and cerebral oxygenation, caused by rostral CSF movement which increases intracranial pressure. The primary aim of this study was to determine the relationship between injected volume and CBFV changes. We hypothesised that this volume-blood flow relationship would have a similar albeit inverted shape to the well-known intracranial pressure volume-pressure curve. METHODS: Fifteen subjects, age 0-6 months, mean (range) weight 4.9 (2.1-6.4) kg, were studied. A 1.5 ml kg-1 caudal injection of 0.2% ropivacaine was administered in three phases separated by two pauses. Subjects were randomised into five groups, in whom the pauses were implemented at different pre-set proportions of the total injected volume. Middle cerebral artery Doppler ultrasonography was used for CBFV measurements (Vmax, peak CBF velocity; Vmin, lowest CBF velocity; velocity time index). Mean flow velocity, pulsatility index, and resistivity index were calculated, and haemodynamic parameters were recorded. RESULTS: CBFV parameters decreased in all patients. The most affected parameter, Vmin, was reduced by ∼50% (range 15-68%) compared with baseline. There was a nonlinear relationship between the volume of the first phase injection and the CBFV measurement during the first pause. Across all time points, there was a linear relationship between volume administered and CBFV. Systemic haemodynamic parameters remained stable throughout the study. CONCLUSIONS: Injection pauses appear to attenuate adverse CBFV increases during administration of a high-volume caudal block.

Real-Time Ultrasound Improves Accuracy of Caudal Block in Children.

BACKGROUND: Caudal block, the most common regional anesthetic in children, is predominantly performed using palpation to determine placement. The efficacy of the palpation technique is unknown with respect to block success. While ultrasound has been suggested for use during caudal block, its use is infrequent. METHODS: A single-blinded prospective observational trial was performed evaluating provider success rate of caudal blocks placed by palpation alone. After needle insertion and partial local anesthetic injection, an ultrasound was performed to confirm correct location. RESULTS: A total of 109 caudal blocks were performed during the prospective observational study. Success rate for caudal blocks done by palpation alone was 78.9% as confirmed by ultrasound. In 21.1% of caudal blocks, the provider incorrectly judged the needle to be in the caudal space as confirmed with ultrasound. CONCLUSIONS: Real-time ultrasound visualization of local anesthetic injection provides reliable and immediate confirmation during caudal block in children.

Analysis of 1478 Cases of Hypospadias Repair: The Incidence of Requiring Repeated Anesthetic Exposure as Well as Exploration of the Involvement of Trainees on Case Duration.

BACKGROUND: Recently, there has been significant focus on the effects of anesthesia on the developing brain. Concern is heightened in children <3 years of age requiring lengthy and/or multiple anesthetics. Hypospadias correction is common in otherwise healthy children and may require both lengthy and repeated anesthetics. At academic centers, many of these cases are performed with the assistance of anesthesia and surgical trainees. We sought to identify both the incidence of these children undergoing additional anesthetics before age 3 as well as to understand the effect of trainees on duration of surgery and anesthesia and thus anesthetic exposure (AE), specifically focusing on those cases >3 hours. METHODS: We analyzed all cases of hypospadias repair from December 2011 through December 2018 at Texas Children's Hospital. In all, 1326 patients undergoing isolated hypospadias repair were analyzed for anesthesia time, surgical time, provider types involved, AE, caudal block, and additional AE related/unrelated to hypospadias. RESULTS: For the primary aim, a total of 1573 anesthetics were performed in children <3 years of age, including 1241 hypospadias repairs of which 1104 (89%) were completed with <3 hours of AE. For patients with <3 hours of AE, 86.1% had a single surgical intervention for hypospadias. Of patients <3 years of age, 17.3% required additional nonrelated surgeries. There was no difference in anesthesia time in cases performed solely by anesthesia attendings versus those performed with trainees/assistance (16.8 vs 16.8 minutes; P = .98). With regard to surgery, cases performed with surgical trainees were of longer duration than those performed solely by surgical attendings (83.5 vs 98.3 minutes; P < .001). Performance of surgery solely by attending surgeon resulted in a reduced total AE in minimal alveolar concentration (MAC) hours when compared to procedures done with trainees (1.92 vs 2.18; P < .001). Finally, comparison of patients undergoing initial correction of hypospadias with subsequent revisions revealed a longer time (117.7 vs 132.2 minutes; P < .001) and AE during the primary stage. CONCLUSIONS: The majority of children with hypospadias were repaired within a single AE. In general, most children did not require repeated AE before age 3. While presence of nonattending surgeons was associated with an increase in AE, this might at least partially be due to differences in case complexity. Moreover, the increase is likely not clinically significant. While it is critical to maintain a training environment, attempts to minimize AE are crucial. This information facilitates parental consent, particularly with regard to anesthesia duration and the need for additional anesthetics in hypospadias and nonhypospadias surgeries.

Effects of awake caudal anesthesia on mean arterial blood pressure in very low birthweight infants.

BACKGROUND: Intraoperative blood pressure is a relevant variable for postoperative outcome in infants undergoing surgical procedures. It is therefore important to know whether the type of anesthesia has an impact on intraoperative blood pressure management in very low birth weight infants. Here, we retrospectively analyzed intraoperative blood pressure in very low birthweight infants receiving either awake caudal anesthesia without sedation, or caudal block in combination with general anesthesia, both for open inguinal hernia repair. METHODS: Ethical approval was provided by the University of Tuebingen Ethical Committee on 05/29/2018 with the project number 403/2018BO2. Patient records of infants admitted by the neonatologist (median age at birth 31.1 ± 3.5 weeks, median weight at birth 1240 ± 521 g) which were scheduled for inguinal hernia repair were retrospectively evaluated for the course of mean arterial blood pressure and perioperative interventions to stabilize blood pressure. A total of 42 patients were included, 16 patients (11 boys, 5 girls) received awake caudal anesthesia, 26 patients (22 boys, 4 girls) a combination of general anesthesia and caudal block. RESULTS: Approximately 3% of the measured mean arterial blood pressure values in the caudal anesthesia group were below a critical margin of 35 mmHg, in contrast to 47% in the combined anesthesia group (p < 0.001). Patients in the latter group showed a significantly larger drop of mean arterial blood pressure below 35 mmHg (4.7 ± 2.7 mmHg vs. 1.9 ± 1.6 mmHg; p < 0.005) and a significantly longer time of mean arterial blood pressure below 35 mmHg (25.6 ± 26.0 min vs. 0.9 ± 2.3 min; p < 0.001), although they received more volume and vasopressor boluses for stabilization (27 ± 14.8 ml vs. 10 ± 4.1 ml; p < 0.01 and 0.15 ± 0.06 ml vs. 0 ml of cafedrine/theoadrenaline; p < 0.001). CONCLUSIONS: The study indicates that the use of caudal block as stand alone procedure for inguinal hernia repair in very low birthweight infants might be advantageous in preventing critical blood pressure drops compared to a combination of caudal block with general anesthesia.

Confirmation of success rate of landmark-based caudal blockade in children using ultrasound: A prospective analysis.

BACKGROUND: Caudal epidural anesthesia is a frequently performed regional anesthesia block in infants and young children. Traditional landmark-based blind needle insertion remains the norm with no immediate, objective method to determine the presence of local anesthetic in the epidural space. Increasingly, ultrasound-imaging is used in pediatric regional anesthesia with demonstrated improvements in block efficacy and efficiency. The value of ultrasound-imaging in confirming success rate of traditional caudal placement is not well defined. AIM: To assess the success rate of conventional landmark-based caudal technique using ultrasound-imaging. METHODS: Prospective observational study of 30 children ages 1 month to 7 years undergoing surgical procedures with consent for caudal blockade. Provider success rate of caudal blockade placed by landmark technique was measured using ultrasound-imaging of needle tip and local anesthetic flow in the epidural space. RESULTS: Ultrasound-imaging demonstrated 80% success to correct positioning of the needle tip and local anesthetic in the epidural space. Failure was associated with decreasing experience and presence of anatomic variances. All improperly positioned needles were subsequently successfully positioned using real-time ultrasound-imaging. Mean time for confirmatory ultrasound-imaging (SD; range) was 1 minute (0.3; 1-3). CONCLUSION: The use of ultrasound-imaging can be used to identify proper needle placement in the sacral epidural canal and facilitate subsequent corrected placement.

Systemic and regional cerebral perfusion in small infants undergoing minor lower abdominal surgery under awake caudal anaesthesia: An observational study.

BACKGROUND: Infants undergoing general anaesthesia have an increased risk of severe respiratory and cardiovascular critical events. Awake caudal anaesthesia is an alternative for small infants undergoing minor lower abdominal surgery. While clinical experience has shown stable intra-operative haemodynamic conditions, there are no studies evaluating systemic and regional cerebral perfusion during such a procedure. OBJECTIVES: The purpose of this study was to evaluate the effects of awake caudal anaesthesia on systemic and regional cerebral perfusion in small infants. DESIGN: A prospective observational cohort study. SETTING: Clinic of Anaesthesiology, University Children's Hospital, between November 2017 and June 2018. PATIENTS: Twenty small infants (postmenstrual age 36 to 54 weeks, weight 1800 to 5700 g) scheduled for lower abdominal surgery under awake caudal anaesthesia were enrolled in this study. INTERVENTION: Standard monitoring was expanded to include cardiac index using electrical velocimetry and regional cerebral oxygen saturation using near infrared spectroscopy. The caudal block was performed with 0.3% ropivacaine 1 ml kg Hypotension was defined as mean arterial blood pressure (BP) less than 35 mmHg and regional cerebral desaturation as regional cerebral oxygen saturation less than 80% of baseline. MAIN OUTCOMES: Mean arterial BP, cardiac index and regional cerebral oxygen saturation parameters under awake caudal anaesthesia. RESULTS: Mean arterial BP, cardiac index and regional cerebral oxygen saturation remained above the predefined lower limits. No episodes of hypotension or regional cerebral desaturation were observed. Operation time was 35 ±â€Š13 (range 20 to 71) min. The infants were discharged to the neonatal ward after the end of surgery, and milk was fed 22 ±â€Š15 (range 6 to 55) min thereafter. Five preterm infants experienced self-limiting episodes of apnoea intra-operatively. CONCLUSION: The current study shows that awake caudal anaesthesia does not impair systemic and regional cerebral perfusion in small infants. TRIAL REGISTRATION: German registry of clinical studies (DRKS-ID: 800015742).

Anatomical Evaluation of the Sacral Hiatus Using Ultrasound Imaging: Factors That Inhibit Needle Insertion During Caudal Epidural Block Procedures.

OBJECTIVE: Caudal epidural blocks often fail due to the difficulty of appropriate needle insertion. This study aimed to evaluate the anatomy of the sacral hiatus using ultrasound imaging. METHODS: This was a retrospective study involving 76 patients with spinal disorders. The following factors were analyzed to see if they affected the palpability of the sacral hiatus: sex, body mass index (BMI), and the morphology of the sacral hiatus on ultrasound imaging. The difficulty of needle insertion and the factors that influenced it were investigated in 28 of the 76 patients, who underwent landmark-based caudal epidural block procedures performed by the same doctor. RESULTS: Among the 76 patients, the mean length of the sacral hiatus was 21.3 ± 5.6 mm, the mean distance from the skin to the sacral cornua was 5.2 ± 3.4 mm, and the mean angle of the sacral hiatus was 16.4 ± 5.5 degrees. Sacral base protrusion was present and absent in 35 and 41 cases, respectively. The sacral hiatus exhibited good and poor palpability in 53 and 23 cases, respectively. The mean distance from the skin to the sacral cornua and BMI were found to significantly influence the palpability of the sacral hiatus. Only sacral base protrusion significantly influenced the difficulty of needle insertion. CONCLUSION: The mean distance from the skin to the sacral cornua and BMI were found to be associated with the palpability of the sacral hiatus, and sacral base protrusion was demonstrated to be associated with the difficulty of needle insertion into the sacral hiatus.