Two different doses of caudal neostigmine co-administered with levobupivacaine produces analgesia in children

Background: This study was aimed to evaluate the analgesic efficacy, duration of analgesia, and side effects of two different doses of caudal neostigmine used with levobupivacaine in children. Methods: Sixty boys, between 5 months and 5 years, undergoing genito‐urinary surgery were allocated randomly to one of three groups (n = 20 each). Group I patients received caudal 0.25% levobupivacaine (1 ml·kg^?1) alone. Groups II and III patients received neostigmine (2 and 4 μg·kg^?1 respectively) together with levobupivacaine used in the same dose as Group I. Pain scores were assessed using Children’s and Infant’s Postoperative Pain Scale (CHIPPS) at 15th (t₁) min after arrival to postanesthetic care unit, and 1st (t₂), 2nd (t₃), 3rd (t₄), 4th (t₅), 8th (t₆), 16th (t₇), and 24th (t₈) hour postoperatively. Duration of analgesia, amount of additional analgesic (paracetamol), score of motor blockade and complications were recorded for 24 h postoperatively, and compared between groups. Results: CHIPPS scores were higher during t₂, t₃, t₆, t₇ and t₈ periods, duration of analgesia was shorter, and total analgesic consumption was higher in Group I compare to neostigmine groups (P < 0.05). Duration of postoperative analgesia and total analgesic consumption were similar in Groups II and III (P > 0.05). Adverse effects were not different between three groups. Conclusions: Caudal neostigmine in doses of 2 and 4 μg·kg^?1 with levobupivacaine extends the duration of analgesia without increasing the incidence of adverse effects, and 2 μg·kg^?1 seems to be the optimal dose, as higher dose has no further advantages.     

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

Objectives: To examine the anatomic spread of caudal local anesthetic solution in children aged 1–7 years. Aim: To determine whether incremental increases in the volume of caudal injections of 0.5, 0.75, and 1.0 ml·kg^?1 result in reliable (>90%) and potentially clinically significant increases in the number of vertebral segments reached. Background: Caudal block is one of the most frequently performed pediatric regional analgesic techniques. Traditional formulae suggest that changes in the volume of caudal injectate in the range 0.5–1.0 ml·kg^?1 would have clinically useful effects. Methods: In a single blind design, 45 children aged 1–7 years undergoing caudal block received one of the three predetermined volumes (0.5, 0.75, and 1 ml·kg^?1) of local anesthetic solution containing radio‐opaque contrast under controlled conditions. Following X‐ray examination, the anatomic spread of the block was reported by a radiologist blinded to the volume of solution received. Results: There were 15 children in each group, and they were similar in terms of age, height, and weight. Spread was observed between the 5th lumbar (L5) and 12th thoracic (T12) vertebral levels. A volume of 1 ml·kg^?1 results in a small but significantly greater spread of solution than 0.5 ml·kg^?1 (P < 0.05), but there was no difference between 0.5 and 0.75 ml or between 0.75 and 1.0 ml. No volume reliably reached a level higher than the second lumbar vertebra (L2). Conclusions: Incrementally increasing the volume of injectate between 0.5 and 1.0 results in a modest increase in the spread of the caudal solution. It is unlikely that volumes of <1 ml will reliably reach a vertebral level that is higher than L2.     

Effect of epidural clonidine on minimum local anesthetic concentration (ED50) of levobupivacaine for caudal block in children

Background: Clonidine has the potential to significantly prolong the duration of caudal epidural anesthesia. We investigated the effect of the addition of clonidine to the MLAC of levobupivacaine in a randomized controlled dose–response trial. Methods: A group of 120 children aged <6 years of age received caudal anesthesia with levobupivacaine and 1, 2, or 3 μg·kg^?1 of clonidine. The MLAC was determined according to a Dixon‐Massey protocol. The primary outcome was effective surgical anesthesia. Secondary outcomes were the duration of postoperative analgesia, postoperative pain scores, clonidine side effects, and time to hospital discharge. Results: The MLAC of caudal levobupivacaine was 0.106%, 0.077%, and 0.035% with 1, 2, and 3 μg·kg^?1 of clonidine, respectively. There were significant dose‐dependent increases in median duration of analgesia. The incidence of delayed discharge, somnolence, and PONV was significantly increased in the 3 μg·kg^?1 of clonidine group. Conclusions: Clonidine produces a local anesthetic sparing effect with a dose‐dependent decrease in levobupivacaine MLAC for caudal anesthesia. In addition, there is a dose‐dependent prolongation of postoperative analgesia following lower abdominal surgery in children. A dose of 2 μg·kg^?1 of clonidine provides the optimum balance between improved analgesia and minimal side effects.     

Levobupivacaine–tramadol combination for caudal block in children: a randomized,double‐blinded,prospective study1

Background: The aim of this prospective study was to compare the postoperative analgesic efficacy and duration of analgesia after caudal levobupivacaine 0.125% or caudal tramadol 1.5 mg·kg⁻¹ and mixture of both in children undergoing day‐case surgery. Methods: Sixty‐three American Society of Anesthesiologists (ASA) I or II children between 1 and 7 years old scheduled for inguinal hernia repair under sevoflurane anesthesia were randomized to receive caudal levobupivacaine 0.125% (group L), caudal tramadol 1.5 mg·kg⁻¹ (group T) or mixture of both (group LT) (total volume of caudal solution was 1 ml·kg⁻¹). Duration of analgesia and requirement for additional analgesics were noted. Postoperative pain was evaluated using the Children’s and Infants’ Postoperative Pain Scale (CHIPPS) every 15 min for the first hour, and after 2, 3, 4, 6, 12, and 24 h. Analgesia was supplemented whenever pain score was ≥4. Results: No patient experienced significant intraoperative hemodynamic response to surgical incision. Duration of analgesia was significantly longer in group LT than in group L and group T (545 ± 160 min vs 322 ± 183 min and 248 ± 188 min, respectively) (P < 0.01). There were no significant differences between the group L and group T for duration of analgesia (P > 0.05). There were no significant differences among the groups in the number of patients requiring analgesia after operation (P = 0.7). No signs of motor block were observed after the first postoperative hour in any of the patients. Conclusion: Addition of tramadol increased the duration of analgesia produced by caudal levobupivacaine in children.     

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.     

Transcutaneous CO2 tension effects of clonidine in paediatric caudal analgesia

In adults, clonidine when added to bupivacaine, results in no detectable respiratory depressant effect except when carbon dioxide challenge is performed. However, to date no investigations have quantified this in children. Twenty-four children (nine months to seven years) were randomized in a double-blind study into two groups. After induction, a caudal block was performed with 1 ml·kg^?1 0.25% bupivacaine. Clonidine 1 μg·kg^?1 was added in the clonidine group, and 1 ml normal saline in the placebo group. Patients were monitored in the recovery room for three h from arrival to discharge with continuous pulse oximetry, respiratory rate, a trancutaneous CO₂ tension (tcPCO₂) every 15 min, and a four point sedation score every 30 min. Mean tcPCO₂ and respiratory rate values were not different between the two groups. Apnoea and desaturation less than 97% were not observed. The sedation score decreased with time in both groups, and the score time interval was significantly higher in the clonidine group (P<0.05). All the patients left the recovery room with a sedation score of 1, excepting four in the clonidine group with a sedation score of 2. Clonidine 1 μg·kg^?1 with 0.25% bupivacaine mixture in caudal analgesia in children did not induce an increase in tcPCO₂ despite prolonged sedation.     

The effect of caudal vs intravenous morphine on early extubation and postoperative analgesic requirements for stage 2 and 3 single-ventricle palliation: a double blind randomized trial

Background: High‐dose single‐shot caudal morphine has been postulated to facilitate early extubation and to lower initial analgesic requirements after staged single‐ventricle (SV) palliation. Methods: With Institutional Review Board approval and written informed parental consent, 64 SV children aged 75–1667 days were randomized to pre‐incisional caudal morphine–bupivacaine (100 μg·kg^?1 morphine (concentration 0.1%), mixed with 0.25% bupivacaine with 1 : 200 000 epinephrine, total 1 ml·kg^?1) and postcardiopulmonary bypass (CPB) intravenous (IV) droperidol (75 μg·kg^?1) (‘active caudal group’) or pre‐incisional caudal saline (1 ml·kg^?1) and post‐CPB IV morphine (150 μg·kg^?1) with droperidol (75 μg·kg^?1) (‘active IV group’). Assignment remained concealed from families and the care teams throughout the trial. Early extubation failure rates (primary or reintubation within 24 h), time to first postoperative rescue morphine analgesia, and 12‐h postoperative morphine requirements were assessed for extubated patients. Results: Thirty‐one (12 stage 2) SV patients received caudal morphine and 32 (15 stage 2) received IV morphine. Extubation failure rates were 6/31 (19%) for caudal and 5/32 (16%) for IV morphine. For successfully extubated patients (n = 54), active caudal treatment significantly delayed the need for postoperative rescue morphine in stage 3 patients (P = 0.02) but not in stage 2 patients (P = 0.189) (Kaplan–Meier survival analysis with LogRank test). The reduction in 12‐h postoperative morphine requirements with active caudal treatment did not reach significance (P = 0.085) but morphine requirements were significantly higher for stage 2 compared with stage 3 patients (P < 0.001) (two‐way anova in n = 50 extubated patients). Conclusions: High‐dose caudal morphine with bupivacaine delayed the need for rescue morphine analgesia in stage 3 patients. All stage 2 patients required early rescue morphine and had significantly higher postoperative 12‐h morphine requirements than stage 3 patients. Early extubation is feasible for the majority of stage 2 and 3 SV patients regardless of analgesic regimen. The study was underpowered to assess differences in extubation failure rates.     

Effect of caudal block on sevoflurane requirement for lower limb surgery in children with cerebral palsy

Background: Caudal block is a widely used technique for providing perioperative pain management in children. In this randomized double‐blinded study, we evaluated the effects of preoperative caudal block on sevoflurane requirements in children with cerebral palsy (CP) undergoing lower limb surgery while bispectral index (BIS) values were maintained between 45 and 55. Methods: 52 children undergoing Achilles‐tendon lengthening were randomized to receive combined general–caudal anesthesia (caudal group, n = 27) or general anesthesia alone (control group, n = 25). Caudal block was performed with a single dose of 0.7 ml·kg^?1 of 1.0% lidocaine containing epinephrine at 5 μg·ml^?1. The control group received no preoperative caudal block. The endtidal sevoflurane concentrations (ET_sev) were adjusted every minute to maintain the BIS values between 45 and 55. Results: The ET_sev required to maintain the BIS values were not significantly different between the control and caudal groups after induction of anesthesia [2.1 (0.2) vs 2.2 (0.4); P = 0.773]. However, significantly higher ET_sev was observed in the control group before surgical incision [2.0 (0.2) vs 1.8 (0.3); P = 0.013] and during the first 20 min after surgical incision [2.2 (0.3) vs 1.4 (0.3); P < 0.001]. There was no significant difference in BIS values between the control and caudal groups throughout the study period (P > 0.05). In the caudal group, the caudal block was successful in 25 of 27 (92.6%) patients. Conclusions: Caudal block effectively reduced sevoflurane requirements by 36% compared to general anesthesia alone in children with CP undergoing lower limb surgery while BIS values were maintained between 45 and 55.     

Efficacy of bupivacaine‐neostigmine and bupivacaine‐tramadol in caudal block in pediatric inguinal herniorrhaphy

Background: Limited duration of analgesia is among the limitations of single caudal injection with local anesthetics. Therefore, the purpose of this study was to evaluate the effectiveness and safety of bupivacaine in combination with either neostigmine or tramadol for caudal block in children undergoing inguinal herniorrhaphy. Methods: In a double‐blinded randomized trial, sixty children undergoing inguinal herniorrhaphy were enrolled to receive a caudal block with either 0.25% bupivacaine (1 ml·kg^?1) with neostigmine (2 μg·kg^?1) (group BN) or tramadol (1 mg·kg^?1) (group BT). Hemodynamic variables, pain and sedation scores, additional analgesic requirements, and side effects were compared between two groups. Results: Duration of analgesia was longer in group BT (17.30 ± 8.24 h) compared with group BN (13.98 ± 10.03 h) (P = 0.03). Total consumption of rescue analgesic was significantly lower in group BT compared with group BN (P = 0.04). There were no significant differences in heart rate, mean arterial pressure, and oxygen saturation between groups. Adverse effects excluding the vomiting were not observed in any patients. Conclusion: In conclusion, tramadol (1 mg·kg^?1) compared with neostigmine (2 μg·kg^?1) might provide both prolonged duration of analgesia and extended time to first analgesic in caudal block.     

Adequacy of caudal analgesia in children after penoscrotal and inguinal surgery using 0.5 or 1.0 ml·kg−1 bupivacaine 0.125%

To determine the optimal volume of bupivacaine 0.125% for postoperative caudal analgesia, we compared the effectiveness of 0.5 ml·kg^?1 and 1 ml·kg^?1 of bupivacaine 0.125% with 1:200,000 epinephrine in 80 children undergoing penoscrotal and inguinal surgery. The adequacy of caudal analgesia and supplemental analgesic requirements did not differ between the two groups at any time during the first 12 hr after surgery. We conclude that 0.5 ml·kg^?1 of bupivacaine 0.125% with 1:200,000 epinephrine is as effective as 1 ml·kg^?1 of the same solution and recommend its use for penoscrotal surgery. The evidence for ss of 0.5 ml·kg^?1 of bupivacaine 0.125% for inguinal owever, is inconclusive because of an insufficient patients studied.     

Surgical outcome in children undergoing hypospadias repair under caudal epidural vs penile block

Aim and Objective: To evaluate the effect of penile block vs caudal epidural on the quality of analgesia and surgical outcome following hypospadias repair. Background: Intraoperative penile engorgement because of caudal epidural may result in tension on surgical sutures and alter surgical outcome. Methods: Fifty‐four ASA I and II children were randomly allocated to group P (penile block, 0.25% bupivacaine, 0.5 mg·kg^?1; n = 27) and group C (caudal epidural, 0.25% bupivacaine, 0.5 ml·kg^?1; n = 27), respectively. Quality of analgesia was assessed by visual analog scale (VAS) score recorded at 0, 0.5, 3, 6, 12, 24 h, and once a day for the next 4 days. Duration of analgesia was calculated from the institution of block to the first analgesic demand by child or VAS > 5. Total morphine consumption in the first 48 h and oral paracetamol consumption till 5th day were recorded. Children were regularly followed up in their respective outpatient clinic for early or late complications. Results: In group P, lower mean VAS scores were seen from 0.5 h after surgery till day 3 and analgesia lasted for significantly longer duration (82 min) when compared with caudal epidural, P < 0.001. Incidence of urethral fistula formation after primary hypospadias repair was 19.2%, and all had received caudal epidural. An increase of 27% in penile volume from baseline value was observed 10 min after caudal epidural placement, P < 0.05. Conclusion: Penile block provided better analgesia when compared with caudal epidural in children undergoing primary hypospadias repair. Postoperative urethral fistula formation was more likely in children who received caudal epidural.     

Midazolam for caudal analgesia in children: comparison with caudal bupivacaine

In a randomized, double-blind study we have examined the analgesic efficacy of caudal administration of midazolam, bupivacaine, or a mixture of both drugs in 45 children, undergoing inguinal herniotomy. They were allocated randomly into three groups (n = 15 in each) to receive a caudal injection of either 0.25% bupivacaine 1 ml · kg^?1 with or without midazolam 50 μg · kg^?1 or midazolam 50 μg · kg^?1 with normal saline 1 ml · kg^?1. There were no differences in quality of pain relief, postoperative behaviour or analgesic requirements between the midazolam group and the other two groups. Times to first analgesic administration (paracetamol suppositories) were longer (P < 0.001) in the bupivacaine-midazolam group than in the other two groups. Further, the bupivacaine-midazolam group received fewer (P < 0.05) doses of paracetamol than the bupivacaine group. Side effects such as motor weakness, respiratory depression or prolonged sedation were not observed in patients who received caudal epidural midazolam only. We conclude that caudal midazolam in a dose of 50 μg · kg^?1 provides equivalent analgesia to bupivacaine 0.25%, when administered postoperatively in a volume of 1 ml · kg^?1 for children following unilateral inguinal hemiotomy.

     

Clonidine-mepivacaine mixture vs plain mepivacaine in paediatric surgery

In a double-blind study, 42 children, aged 1–10, undergoing general subumbilical surgery, were randomly allocated to two groups; they received, via caudal extradural, 1% mepivacaine 7 mg·kg^?1 and normal saline 1 ml (Group 1) and a mixture of 1% mepivacaine 7 mg·kg^?1 plus clonidine 2 μg·kg^?1 and normal saline up to 1 ml (Group 2) respectively. No significant difference was noticed in age, weight, duration of surgery and onset time of anaesthesia, blood pressure, heart rate and oxygen saturation. Mean duration of analgesia (evaluated with ‘Broadman objective pain scale') was 143 min for Group 1 and 218 min for Group 2 (P < 0.05); the time of sedation (evaluated with a sedation score) was statistically longer in Group 2 (172 min vs 89 min in Group 1). This longer sedation is due both to the longer analgesia and partially to a side effect of clonidine. In conclusion the addition of 2 μg·kg^?1 of clonidine to mepivacaine prolongs the duration of caudal analgesia in children.     

The hemodynamic effects of newborn caudal anesthesia assessed by transthoracic echocardiography: a randomized, double-blind, controlled study

Background: Caudal anesthesia has been increasingly used in abdominal, urinary tract, and lower extremity surgery of infants. However, little was known about the hemodynamic effects of caudal anesthesia in them, especially in neonates. The purpose of this prospective study was designed to investigate the hemodynamic alterations by transthoracic echocardiography in newborn baby after caudal anesthesia with plain Bupivacaine or with epinephrine added Bupivacaine. Methods: Thirty full‐term newborn infants scheduled for lower abdominal or urinary tract surgery were randomly allocated into three groups (n = 10 each) as follows: (i) GA group: general anesthesia with sevoflurane; (ii) GA+CP group: GA with sevoflurane, combined with caudal anesthesia of plain Bupivacaine (1.25 ml·kg^?1 of 0.2%); (iii) GA+CA group: sevoflurane GA combined with caudal anesthesia of epinephrine‐added Bupivacaine (1.25 ml·kg^?1 of 0.2% Bupivacaine plus 1/200 000 epinephrine). Cardiac output (CO), arterial blood pressure, and heart rate were measured before (T‐5) and 5(T5), 10(T10), 15(T15) min after performance of caudal anesthesia. Results: In GA group, no significant hemodynamic alteration was observed in comparison with T‐5, except HR, which decreased by 7% at T15; In GA+CP group, compared with T‐5, HR decreased significantly at T5, T10 and T15, respectively, by 6%, 7% and 10%. And also CO decreased significantly at T15 by 8% compared with T‐5; In GA+CA group, no significant hemodynamic alteration was observed expect diastolic arterial blood, which decreased significantly at T15 by 10% compared with T‐5; At T15, the larger decrease of systolic arterial blood in GA+CP group and GA+CA group vs (GA) group (P < 0.05). Conclusions: The study shows the stability of hemodynamic variables during caudal anesthesia with Bupivacaine and with epinephrine‐added Bupivacaine in newborn infants.     

Unilateral groin surgery in children: will the addition of an ultrasound‐guided ilioinguinal nerve block enhance the duration of analgesia of a single‐shot caudal block?

Background: Inguinal hernia repair, hydrocelectomy, and orchidopexy are commonly performed surgical procedures in children. Postoperative pain control is usually provided with a single‐shot caudal block. Blockade of the ilioinguinal nerve may lead to additional analgesia. The aim of this double‐blind, randomized controlled trial was to evaluate the efficacy of an adjuvant blockade of the ilioinguinal nerve using ultrasound (US) guidance at the end of the procedure with local anesthetic vs normal saline and to explore the potential for prolongation of analgesia with decreased need for postoperative pain medication. Methods: Fifty children ages 1–6 years scheduled for unilateral inguinal hernia repair, hydrocelectomy, orchidopexy, or orchiectomy were prospectively randomized into one of two groups: Group S that received an US‐guided ilioinguinal nerve block with 0.1 ml·kg^?1 of preservative‐free normal saline and Group B that received an US‐guided nerve block with 0.1 ml·kg^?1 of 0.25% bupivacaine with 1 : 200 000 epinephrine at the conclusion of the surgery. After induction of anesthesia but prior to surgical incision, all patients received caudal anesthesia with 0.7 ml·kg^?1 of 0.125% bupivacaine with 1 : 200 000 epinephrine. Patients were observed by a blinded observer for (i) pain scores using the Children and Infants Postoperative Pain Scale, (ii) need for rescue medication in the PACU, (iii) need for oral pain medications given by the parents at home. Results: Forty‐eight patients, consisting of 46 males and two females, with a mean age of 3.98 (sd ± 1.88) were enrolled in the study. Two patients were excluded from the study because of study protocol violation and/or alteration in surgical procedure. The average pain scores reported for the entire duration spent in the recovery room for the caudal and caudal/ilioinguinal block groups were 1.92 (sd ± 1.59) and 1.18 (sd ± 1.31), respectively. The average pain score difference was 0.72 (sd ± 0.58) and was statistically significant (P < 0.05). In addition, when examined by procedure type, it was found that the difference in the average pain scores between the caudal and caudal/ilioinguinal block groups was statistically significant for the inguinal hernia repair patients (P < 0.05) but not for the other groin surgery patients (P = 0.13). For all groin surgery patients, six of the 23 patients in the caudal group and eight of the 25 patients in the caudal/ilioinguinal block group required pain rescue medications throughout their entire hospital stay or at home (P = 0.76). Overall, the caudal group received an average of 0.54 (sd ± 1.14) pain rescue medication doses, while the caudal/ilioinguinal block group received an average of 0.77 (sd ± 1.70) pain rescue medication doses; this was, however, not statistically significant (P = 0.58). Conclusions: The addition of an US‐guided ilioinguinal nerve block to a single‐shot caudal block decreases the severity of pain experienced by pediatric groin surgery patients. The decrease in pain scores were particularly pronounced in inguinal hernia repair patients.     

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.     

Impact of caudal block on functional residual capacity and ventilation distribution in anaesthetized preschool children

Introduction: In children, general anaesthesia is often performed in combination with regional anaesthesia and caudal block (CB) is probably the most commonly used central neuroaxial blockade. The administration of local anaesthetics results in a motor blockade. The impact of this motor blockade induced by CB on the functional residual capacity (FRC) and ventilation distribution is unknown. The aim of this study was to determine the impact of CB versus control on FRC and ventilation distribution in preschool children. We hypothesized that an effective CB would lead to an increase of FRC and ventilation distribution while these parameters would remain unchanged in the control group. Methods: After approval from the local Ethics Committee, 52 preschool children (15–30 kg, 3–8 years) without cardiopulmonary disease who were to undergo elective surgery requiring combined general/regional anesthesia with a CB, were randomly allocated into two groups: CB (n = 26) or control (n = 26). Anesthesia was standardized using a propofol TCI for children. All children were breathing spontaneously via a laryngeal mask airway. FRC and lung clearance index (LCI), a measure of ventilation distribution, were calculated using a sulfur‐hexafluoride gas (SF₆) multibreath washout technique. A blinded reviewer performed off‐line analyses of the data. Following the first measurement in the supine position (baseline), all children were turned into the left‐lateral position. The CB group received a CB (0.2 ml·kg^‐1 bupivacaine 0.25% + epinephrine 1: 200 000 test dose and 0.8 ml·kg^‐1 bupivacaine 0.175%), while in the control group no intervention took place. After 5 min in the lateral position, all children were turned back to the supine position. After 15 min, the effectiveness of the CB was tested by pinching the skin at the L1 level with any movement being taken as a noneffective block (n = 0), and the second FRC assessment was performed in both groups. Results: At baseline, FRC and LCI were similar for the two groups. In the CB group, FRC (mean ± SD) increased from 17.0 ± 4.3 ml·kg^‐1 to 20.5 ± 5.1 ml·kg^‐1 (P < 0.0001) after an effective CB while FRC in the control group remained unchanged (17.2 ± 4.9 ml·kg^‐1 to 17.1 ± 4.8 ml·kg^‐1 (P = 0.0757). At the same time, the LCI decreased from 12.0 ± 2.5 to 9.37 ± 1.7 (P < 0.0001) in the CB group, while it remained constant in the control group (10.8 ± 2.7 vs 10.7 ± 2.6, P = 0.1515). Conclusions: CB resulted in a significantly increased FRC and ventilation distribution, whereas these parameters did not change in the control group. This indicates that a CB could have a major impact on respiratory function in anaesthetized, spontaneously breathing children. Additionally, the constant values for FRC and LCI in the control group showed that there was no ‘over‐time’ effect on these two parameters during the assessed study period. Acknowledgement: The study was funded by the Department of Anaesthesia, University of Basel, Switzerland and by the Swiss Association of Anaesthesia and Reanimation (SGAR).     

Clonidine does not improve quality of ropivacaine axillary brachial plexus block in children

Background: The addition of clonidine to peripheral nerve blocks is controversial in children. Objective: The aim of our study was to evaluate the effect of clonidine added to ropivacaine in pediatric axillary brachial plexus block (ABPB). Methods: Children aged 1–6 years, scheduled to undergo forearm or hand surgery, were recruited into this prospective, double‐blind controlled trial. Patients were randomly allocated to receive an ABPB either with ropivacaine 0.2% 0.4 ml·kg^?1 plus saline in 1 ml (RS) or ropivacaine 0.2% 0.4 ml·kg^?1 plus clonidine 1 μg·kg^?1 in 1 ml (RC). Primary endpoints were quality of postoperative analgesia as assessed by pain scores and total 24‐h postoperative analgesia requirements. Secondary outcomes were time to first analgesia request and duration of motor blockade. Results: Sixty patients were recruited (n = 30 per group) into the study. Pain scores were comparable throughout the first 24 h between the two groups. Ten children in the (RS) and six in (RC) groups required supplementary analgesia during the first 24 h (P = 0.24). Children who required further analgesia did so after 288 ± 94 min in the (RS) and 437 ± 204 min in the (RC) group (P = 0.06). There was no difference in the duration of motor block [186 ± 71 and 154 ± 56 min, P = 0.12 for (RS) and (RC), respectively]. Conclusion: Ropivacaine (0.2% 0.4 ml·kg^?1) for ABPB provides sufficient postoperative analgesia in children scheduled for forearm or hand surgery. The addition of clonidine to ABPB does not improve overall postoperative analgesia but may increase the time to first analgesia request.     

Changes of dorsalis pedis artery flow pattern after caudal block in children: observational study using a duplex sonography

Objective: To evaluate the changes of the flow velocity, the volume flow, and the diameter of dorsalis pedis artery using a duplex ultrasonography after caudal block with sevoflurane anesthesia in children. Aim: To know the acute change in peripheral arterial flow patterns of sympathetically blocked lower limbs in anesthetized children. Background: Caudal analgesia in combination with general anesthesia may affect the circulatory hemodynamics due to sympatholytic vasodilating effects. Methods: After approval by the Ethics Committee, we evaluated the changes of peripheral hemodynamics using a duplex ultrasonography before and after a caudal block in sevoflurane‐anesthetized children. Results: A caudal block using 0.15% ropivacaine 1.5 ml·kg^?1 significantly altered the arterial flow patterns; increased peak velocity (24%) and volume flow (76%), and the diameter of the dorsalis pedis artery (20%) in children. However, blood pressures and heart rates were not affected significantly by caudal block. Conclusions: Duplex sonographic measurements indicate that a caudal block changes the flow patterns of the dorsalis pedis artery significantly in the anesthetized children.     

Continuous caudal anaesthesia with chloroprocaine as an adjunct to general anaesthesia in neonates

Purpose

The authors prospectively evaluated the use of a continuous caudal epidural infusion of chloroprocaine as an adjunct to genera! anaesthesia during intra-abdominal surgery in neonates.

Clinical features

The technique was used in 25 neonates ranging in age from 1 to 28 days and in weight from 2.2 to 4.9 kg. Following anaesthetic induction and tracheal intubation, an initial bolus dose of chloroprocaine 3% (1 or 1.5 ml · kg^?1) was followed by a continuous infusion of 1 or 1.5 ml · kg^?1 · hr^?1 administered through a caudal epidural catheter. No parenteral opioids were administered. The duration of the surgical procedures varied from one hour five minutes to three hours 15 min. The first three neonates received a bolus dose of 1.0 ml kg^?1 followed by an infusion of 1.0 ml · kg^?1 · hr^?1 chloroprocaine 3%. These three neonates required an additional bolus dose followed by an increase in the infusion to 1.5 ml · kg^?1 · hr^?1 to provide surgical anaesthesia. Adequate intraoperative anaesthesia was achieved in all 25 neonates with an infusion of 1.5 ml · kg^?1· hr^?1 of chloroprocaine 3%. This was evidenced by a lack of haemodynamic response to surgical manipulation. No neonate required more than 0.2% isoflurane or 70% nitrous oxide in oxygen. No episodes of haemodynamic instability (decreased blood pressure/bradycardia) related to the caudal epidural anaesthesia were noted. Twenty-three of 25 of the neonates’ tracheas were extubated immediately (within 10 minutes) following the surgical procedure.

Conclusions

Caudal anaesthesia with a continuous infusion of chloroprocaine can be used as an adjunct to general anaesthesia during abdominal surgery in neonates. Our initial experience suggests that the combined technique may eliminate the need for parenteral opioids and limit the intraoperative requirements for inhalational anaesthetic agents.