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.     

The hemodynamic effects of pediatric caudal anesthesia assessed by esophageal Doppler

Pediatric caudal anesthesia is an effective method with an infrequent complication rate. However, little is known about its cardiovascular consequences. Transesophageal Doppler, a noninvasive method, provides the opportunity for a reappraisal of the hemodynamic effects of this technique. After parental informed consent, we studied 10 children aged 2 mo to 5 yr who were scheduled for lower abdominal surgery. General anesthesia was induced using sevoflurane and was followed by the insertion of a transesophageal Doppler probe. Caudal anesthesia was performed using 1 mL/kg of 0.25% bupivacaine with 1/200,000 epinephrine. Hemodynamic variables were collected before and after caudal anesthesia. No complications arose during insertion of the probe. The mean time between the two sets of measurements was 15 min. Heart rate, systolic, diastolic, and mean arterial blood pressures were not modified by caudal anesthesia. Descending aortic blood flow increased significantly from 1.14 to 1.92 L/min. (P = 0.0002). Aortic ejection volume increased from 8.5 to 14.5 mL (P = 0.0002). Aortic vascular resistances decreased from 6279 to 3901 dynes. s(-1) x m(-5) (P = 0.005). Caudal anesthesia did not affect heart rate and mean arterial blood pressure but induced a significant increase in descending aortic blood flow. IMPLICATIONS: Although pediatric caudal anesthesia does not alter heart rate nor arterial blood pressure, significant changes occur in regional blood flow distribution. Descending aortic blood flow increases significantly after caudal anesthesia, whereas lower body vascular resistances decrease.     

A survey of pediatric caudal extradural anesthesia practice

Background:  Caudal extradural blockade is one of the most commonly performed procedures in pediatric anesthesia. However, there is little information available on variations in clinical practice.
Objectives:  To perform a survey of members of the Association of Paediatric Anaesthetists of Great Britain and Ireland who undertake caudal anesthesia.
Methods:  An 'online' World Wide Web questionnaire collected information on various aspects of clinical practice. The survey ran from April to June 2008.
Results:  There were 366 questionnaires completed. The majority of respondents had >5 years of pediatric experience and performed up to ten caudal extradural procedures a month. The commonest device used was a cannula (69.7%) with 68.6% using a 22G device. There was a trend toward the use of a cannula in those anesthetists with <15 years experience, while those with >15 years experience tended to use a needle. Most anesthetists (91.5%) did not believe that there was a significant risk of implantation of dermoid tissue into the caudal extradural space. The majority used a combination of clinical methods to confirm correct placement. Only 27 respondents used ultrasound. The most popular local anesthetics were bupivacaine (43.4%) and levobupivacaine (41.7%). The most common additives were clonidine (42.3%) and ketamine (37.5%). The caudal catheter technique was used by 43.6%. Most anesthetists (74%) wear gloves for a single shot caudal injection.
Conclusions:  This survey provides a snapshot of current practice and acts a useful reference for the development of enhanced techniques and new equipment in the future.     

Hemodynamic effects of levobupivacaine after pediatric caudal anesthesia evaluated by transesophageal doppler

Background: The aim of this study is to determine if there are significant differences in hemodynamic effects between combined general‐regional anesthesia using levobupivacaine 0.25% 2 ml·kg^?1 via the caudal route in comparison with balanced general anesthesia using continuous infusion of remifentanil in young children undergoing genitourinary surgery. Patients and methods: 62 ASA I‐II pediatric patients (12 female, 50 male) aged 6 months to 7 years undergoing genitourinary surgery were included in the study. Patients were randomly allocated into one of two groups of 31 patients each. Group Caud received caudal blockade with levobupivacaine 0.25% 2 mg·kg^?1 in combined general‐regional anesthesia and Group Gen received balanced general anesthesia with remifentanil. The noninvasive hemodynamic parameters were measured in each group 5 min after induction of general anesthesia or caudal block (Tcaud), after further 5 min coincident with skin incision (Tsi), 10 min after skin incision (T10i), at the end of surgical procedure (Tend). The time between Tcaud and Tsi was 10 min and the measurements during the interval time T10i‐Tend were performed every 15 min according to the duration of surgical procedures. Results: There was a decrease in all measured hemodynamic parameters at skin incision. The decreases occurred in both groups with those in the caudal group occurring at skin incision and those in the balanced anesthesia group occurring at 10 min after skin incision. These variations showed no significant differences for any of the stated outcomes; neither between the groups at each time point nor in the caudal in comparison with baseline measurements. Conclusions: Using transesophageal Doppler no differences in hemodynamic parameters could be detected between balanced general anesthesia with either caudal levobupivacaine or remifentanil infusion. Both techniques showed good hemodynamic stability with only minor changes from baseline over time which are unlikely to be of clinical significance except possibly in patients with preexisting cardiovascular compromise. Other studies with noninvasive monitoring in a larger population are required to better understand the consequences of caudal blockade on CO and on regional blood flow in infants.     

The effects of caudal local anesthesia blockade on the Bispectral Index during general anesthesia in children

BACKGROUND: Peripheral deafferentation induced by epidural or spinal anesthesia reduces the degree of cortical arousal in adults. This study aimed at determining if caudal blockade decreases the level of arousal, as measured by Bispectral Index (BIS) in unstimulated children, and to determine if this effect differed between age groups. METHODS: Hospital ethics committee approval and parental consent was obtained. Children (age between 24 months and 5 years) and infants (between 6 and 24 months of age) were recruited if they were scheduled for below umbilical surgery that would usually require caudal local anesthesia blockade. Before the procedure, subjects within each age group were randomized to either caudal group (1 ml.kg(-1) 0.25% bupivacaine), or control group (no caudal). In all groups, anesthesia was induced with sevoflurane and maintained at a constant endtidal concentration of 1.5% sevoflurane without N(2)O. Five minutes after induction a baseline BIS was recorded (BIS(1)). In the caudal groups, a caudal block was then performed while in the control groups no block was performed. Fifteen minutes later, the BIS was again recorded (BIS(2)). The change in BIS over this time period was the primary outcome (BIS(Delta)). After measurement, subjects in the control groups received a caudal block before the start of surgery. RESULTS: Twenty-nine infants and 18 children completed the study protocol. In children, BIS(Delta) was significantly different between the caudal group and control (-5.7 vs -0.7, P = 0.04). In infants, no significant difference was detected in BIS(Delta) between caudal and control groups. CONCLUSIONS: Caudal blockade decreased the degree of arousal, as measured by BIS, in unstimulated children aged 2-5 years. No change in arousal was detected in infants.     

Efficacy and safety of clonidine as additive for caudal regional anesthesia: a quantitative systematic review of randomized controlled trials

Background: Clonidine is still the most popular additive for caudal regional anesthesia. Aim of the present quantitative systematic review was to assess the efficacy and safety of the combined use of clonidine and local anesthetics in comparison with caudal local anesthetics alone. Methods: The systematic search, data extraction, critical appraisal and pooled analysis were performed according to the PRISMA statement. The systematic search included the Central register of controlled trials of the Cochrane Library (to present), MEDLINE (1966 to present), EMBASE (1980 to present) and CINAHL (1981 to present). Relative risk (RR), mean difference (MD) and the corresponding 95% confidence intervals (CI) were calculated using the Revman ^® statistical software for dichotomous and continuous outcomes. Results: Twenty randomized controlled trials (published between 1994 and 2010) including 993 patients met the inclusion criteria. There was a longer duration of postoperative analgesia in children receiving clonidine in addition to local anesthetic (MD: 3.98 h; 95% CI: 2.84–5.13; P < 0.00001). Furthermore, there was a lower number of patients requiring rescue analgesics in the clonidine group (RR: 0.72; 95% CI: 0.57–0.90; P = 0.003). The incidence of complications (e.g., respiratory depression) remained very low and was not different to caudal local anesthetics alone. Conclusions: There is considerable evidence that caudally administered clonidine in addition to local anesthetics provides extended duration of analgesia with a decreased incidence for analgesic rescue requirement and little adverse effects compared to caudal local anesthetics alone.     

Levobupivacaine caudal anesthesia in children: a randomized double-blind comparison with bupivacaine

BACKGROUND: Levobupivacaine is the pure S-enantiomer of bupivacaine. Despite obvious benefits in the event of accidental intravascular injection there has been no studies demonstrating a clinically significant benefit to levobupivacaine over racemic bupivacaine for pediatric regional anesthesia. Given the similar pharmacokinetic profiles of both drugs the studies to date have been underpowered to demonstrate what is likely to be a small difference in clinical effectiveness. Our aim was to determine if there are significant differences in the clinical effectiveness of levobupivacaine compared with racemic bupivacaine for caudal anesthesia in children having lower abdominal surgery. A secondary aim was to determine if there are differences in the incidence of postoperative motor blockade between these agents. METHODS: Three hundred and ten children ranging in age from 1 month to 10.75 years in age having lower abdominal surgery were enrolled. Patients were randomized in a double blind manner to receive a caudal block with either 0.25% bupivacaine (n = 152) or 0.25% levobupivacaine (n = 155) to a total volume of 1 ml x kg(-1). Motor blockade (modified Bromage scale) and postoperative pain or distress (FLACC behavioral scale for postoperative pain) were measured at predetermined time points during the subsequent 120 min. RESULTS: There were no significant adverse effects attributable to levobupivacaine. Success rates were defined as a lack of hemodynamic response to first surgical incision and low postoperative pain scores. At a mean duration of 5 min between block completion and first incision success for 1 ml x kg(-1) of 0.25% bupivacaine was 91% and 94% for 0.25% levobupivacaine. Satisfactory postoperative analgesia was present in 98% of patients after bupivacaine caudal anesthesia and 97.5% for levobupivacaine. At 30 min following caudal anesthesia the incidence of postoperative motor block with racemic bupivacaine was 84% and decreased to 7% at 120 min. For levobupivacaine motor block at 30 min postcaudal was present in 85% and decreased to 11% at 120 min. CONCLUSIONS: Levobupivacaine is an effective agent for caudal anesthesia in children at a recommended dose of 2.5 mg x kg(-1). The rapidity of onset was suitable for establishment of surgical anesthesia and postoperative analgesia was achieved in greater than 97.5% of patients. It appears to be of equivalent potency to racemic bupivacaine in children requiring lower abdominal surgery.     

Isoflurane is associated with a similar incidence of emergence agitation/delirium as sevoflurane in young children--a randomized controlled study

BACKGROUND: Children may be agitated or even delirious especially when recovering from general anesthesia using volatile anesthetics. Many trials have focused on the newer agents sevoflurane and desflurane but for the widely used isoflurane little is known about its potential to generate agitation. We investigated the emergence characteristics of small children after sevoflurane or isoflurane with caudal anesthesia for postoperative pain control. METHODS: After institutional approval and parental consent, anesthesia was randomly performed with sevoflurane (n = 30) or isoflurane (n = 29) in children at the age of 3.8 +/- 1.8 years during surgical interventions on the lower part of the body. After induction, all children received caudal anesthesia with bupivacaine (0.25%, 0.8 ml x kg(-1)). Postoperatively, the incidences of emergence agitation (EA) and emergence delirium (ED) were measured by a blinded observer using a ten point scale (TPS; EA = TPS > 5 ED = TPS > 7) as well as vigilance, nausea/vomiting and shivering. RESULTS: The two groups were comparable with respect to demographic data, duration of surgery and duration of anesthesia. There were also no differences in the period of time from the end of surgery until extubation, duration of stay in the PACU, postoperative vigilance and vegetative parameters. Incidence of EA was 30% (9/30) for sevoflurane and 34% (10/29) for isoflurane during the first 60 min in the PACU (P = 0.785). Likewise, the incidence of ED was not different between the groups (20% and 24%, respectively). CONCLUSIONS: In our randomized controlled study, we found no difference in the incidence of EA or ED between sevoflurane and isoflurane. Therefore, the decision to use one or the other should not be based upon the incidence of EA or ED.     

腹腔镜胆囊切除术的硬膜外和全身麻醉比较(500例随机对照研究)

目的比较硬膜外麻醉和气管内全麻在腹腔镜胆囊切除术(laparoscopic cholecystectomy,LC)中的应用效果.方法 500例择期LC术随机分为硬膜外麻醉组(E组,n=250)和气管内全麻组(G组,n=250). 结果 1.血流动力学:CO2气腹后两组心输出量均显著下降(P<0.05),10 min后开始回升,30 min后均恢复到气腹前水平(P>0.05),两组间比较无明显差异;气腹后两组中心静脉压均有显著升高(P<0.05),30 min后恢复正常;气腹后G组平均动脉压显著升高(P<0.05),至停气腹后5 min仍未恢复到气腹前水平,而E组整个气腹期间平均动脉压无明显变化或略低(P>0.05),与G组比较有显著差异(P<0.001); E组气腹后5 min心率明显降低(P<0.05),15 min后恢复到气腹前水平,G组气腹前后心率无明显变化(P>0.05),两组间比较无明显差异.2.呼吸参数:整个气腹期间G组平均气道压、气道峰压显著增高(P<0.01),气腹后E组呼吸频率、每分通气量显著增加(P<0.05),潮气量无明显变化或略有升高,停气腹后5 min即恢复正常.3.动脉血气:气腹后两组PaCO2、HCO3-、pH、PaO2的变化在正常值范围,无临床意义.4.费用:E组住院费用明显低于G组(t=127.192,P=0.000). 结论 ASA I级～II级的患者择期行腹腔镜胆囊切除术,选择硬膜外麻醉安全可行且经济.     

布比卡因混合肾上腺素骶管阻滞对全麻新生儿血液动力学的影响

目的 评价布比卡因混合肾上腺素骶管阻滞对全麻新生儿血液动力学的影响.方法 择期或限期行腹部或会阴部手术的足月新生儿30例,性别不限,ASA Ⅰ或Ⅱ级,出生体重≥2 500 g,日龄≤28 d,随机分为3组(n=10):全麻组(A组)、全麻+骶管阻滞(0.2%布比卡因1.25 ml/kg)组(AP组)和全麻+骶管阻滞(0.2%布比卡因混合1:200 000肾上腺素,1.25 ml/kg)组(AE组).分别于骶管阻滞前5 min(T1)及骶管阻滞后5、10、15 min(T2～4)时采用超声心动图仪监测心率、每搏量、心输出量,记录平均动脉压、收缩压、舒张压,计算全身血管阻力.结果 与TI时比较,A组T4时心率减慢,AP组T2～4时心率减慢,AP组T4时心输出量减少,AE组T4时舒张压降低(P<0.05或0.01);各组间血液动力学指标差异均无统计学意义(P>0.05).结论 单独应用布比卡因或混合肾上腺素行骶管阻滞对全麻新生儿血液动力学无明显影响.     

The effects of caudal or intravenous dexmedetomidine on postoperative analgesia produced by caudal bupivacaine in children: a randomized controlled double-blinded study

Study ObjectivesThe aim of this study was to compare the effects of caudal and intravenous (IV) dexmedetomidine (1 μg/kg) on postoperative analgesia after caudal bupivacaine in pediatric patients undergoing lower abdominal and perineal surgeries.DesignA randomized controlled double-blind study.SettingUniversity-affiliated teaching hospital.PatientsSeventy-five American Society of Anesthesiologists I children, aged 1 to 6 years.InterventionPatients were randomly allocated to 3 groups. All patients received 1 mL/kg caudal 0.25% bupivacaine. In addition, those in group B (n = 25) received 10-mL IV saline, those in group B-D_cau (n = 25) received 1 μg/kg caudal dexmedetomidine and 10-mL IV saline, and those in group B-D_IV (n = 25) received 1 μg/kg IV dexmedetomidine in 10-mL saline.MeasurementsIntraoperative mean blood pressure, heart rate, peripheral oxygen saturation, end-tidal sevoflurane, and bispectral index as well as postoperative pain and behavior scores and time to first analgesia were assessed.Main resultsGroup B-D_cau had a significantly longer time to first rescue analgesia than groups B-D_IV and B, with mean (SD) values of 14.4 (7.5), 9.18 (2.7), and 6.6 (2.5) hours, respectively (P < .05). Fewer patients in group B-D_cau (n = 16) required rescue analgesia during the first 24 hours postoperatively compared to group B (n = 24) and group B-D_IV (n = 20) (P < .05).Groups B-D_cau and B-D_IV had lower pain and behavior scores than Group B. Eight patients Group B had agitation compared to 2 in Group B-D_IV and 0 in Group B-D_cau. Four patients in Group B-D_IV developed bradycardia and hypotension during surgery.ConclusionsCompared to IV administration, caudal administration of dexmedetomidine during caudal bupivacaine anesthesia provided prolonged postoperative analgesia and a greater analgesic sparing effect without significant side effects. This suggests a greater role of neuraxial compared to that of peripheral α-2 adrenoceptors in pain processing.     

The effects of caudal or intravenous clonidine on postoperative analgesia produced by caudal levobupivacaine in children

Background: Clonidine is used increasingly in pediatric anesthesia practice to prolong the duration of action of caudal block with a local anesthetic agent. Which route of administration of clonidine is the most beneficial remains unknown. We compared the effects of caudal and intravenous clonidine on postoperative analgesia produced by caudal levobupivacaine. Methods: Sixty ASA I and II children, aged 2–8 undergoing inguinal hernia repair or orchidopexy surgery received standardized premedication with midazolam and general anesthesia. The children were randomized in a double‐blind fashion to three groups. Group L (n = 20) patients received 0.75 ml·kg^?1 of caudal 0.25% levobupivacaine and i.v. 5 ml saline, Group L‐Ccau (n = 20) patients received 0.75 ml·kg^?1 of caudal 0.25% levobupivacaine + 2 μg·kg^?1 clonidine and i.v. 5 ml saline, Group L‐Civ (n = 20) patients received 0.75 ml·kg^?1 of caudal 0.25% levobupivacaine and i.v. 2 μg·kg^?1 clonidine in 5 ml of saline. Mean arterial blood pressure, heart rate, peripheral oxygen saturation, and end‐tidal carbon dioxide values were recorded. Postoperative pain [Children and Infants Postoperative Pain Scale (CHIPPS) score], sedation (Ramsay Sedation Scale) and motor blockade (Modified Bromage Scale) were assessed at predetermined time points during the first 24 h after surgery. Results: Caudal clonidine significantly delayed the time to first rescue analgesic and fewer patients required rescue analgesia in the 24 h after surgery. No motor block was observed in any of the three groups on awakening or during the study period. In Group L‐Ccau, the CHIPPS score was lower than in Group L at all times through 240 min (P < 0.05), while the pain scores were lower in Group L‐Civ only at extubation and at 240 min (P < 0.05). Conclusions: Caudal clonidine prolongs the duration of analgesia produced by caudal levobupivacaine without causing significant side effects and this is because of a spinal mode of action.     

Incidence of self‐limiting back pain in children following caudal blockade: an exploratory study

Background: Currently, in pediatric anesthesia, there is no evidence‐based information available to pediatric patients and their parents regarding the incidence of back pain after neuraxial injections performed for postoperative analgesia. Back pain postepidural blockade has been reported in numerous studies with adult patients; however, it has not been investigated in children. The main objective of this study is to examine the incidence of back pain symptoms after caudal blockade (early and late onset) in children. Methods: Patients under the age of 18 years, who received caudal blockade at the Montreal Children’s Hospital between July 2006 and December 2008 were recruited in this prospective observational study. Back pain was measured prospectively by patient self‐report and parental observation during the 15‐day postoperative period. Patients, or their parents, were contacted by phone on postoperative day 2 (POD2) and postoperative day 15 (POD15) to answer a seven‐item symptom questionnaire. Results: In a sample of 135 children, the incidence of back pain symptoms was 4.7% and 1.1% on POD2 and POD15, respectively. Conclusions: The results of this study provide support that transient self‐limiting back pain after caudal blockade does occur in pediatric patients. Clinically, this is useful information for physicians to provide to their patients. An exploration of factors that may be associated with back pain following caudal blockade in children is an interesting area of future research.