Spinal versus peripheral effects of adjunct clonidine: comparison of the analgesic effect of a ropivacaine-clonidine mixture when administered as a caudal or ilioinguinal-iliohypogastric nerve blockade for inguinal surgery in children

Ultrasound-guided retrolaminar block versus ilioinguinal nerve block for postoperative analgesia in children undergoing inguinal herniotomy: A randomized controlled trial

STUDY OBJECTIVE

Ultrasound-guided retrolaminar block (RLB) is a new, safe and technically easy nerve block. To our knowledge, no studies have evaluated its analgesic efficacy in pediatric patients. This study aimed to compare the postoperative analgesic efficacy of RLB and ilioinguinal nerve block (INB) in pediatric patients undergoing unilateral inguinal herniotomy.

DESIGN

Superiority, prospective, randomized, double-blinded, controlled study.

SETTING

Operating rooms and wards of Mansoura University Children's Hospital, Egypt.

PATIENTS

Sixty-five patients aged 2 to 6 years undergoing unilateral inguinal herniotomy were enrolled.

INTERVENTIONS

In the ultrasound-guided RLB group (n = 30), we injected 0.5 mL/kg bupivacaine 0.25% into the retrolaminar space between the lamina of T12 and the paraspinal muscles and in ultrasound-guided INB group (n = 30), 0.5 mL/kg bupivacaine 0.25% was injected for INB.

MEASUREMENTS

The primary outcome measure was the number of patients requiring ibuprofen as rescue analgesia and the secondary outcome measures were intraoperative hemodynamic changes and the postoperative FLACC (Face, Legs, Activity, Cry, Consolability) score.

MAIN RESULTS

The number of patients who needed rescue analgesia in the first postoperative 24 h was significantly lower (P = 0.023) in the RLB group [5 (16%)] than the INB group [13 (43%)]. The mean (SD) arterial blood pressure and heart rate were significantly higher (P < 0.001) during sac traction in the INB group [74.07 (2.99), 97.33 (6.98)] than the RLB group [67.73 (3.55), 90.79 (5.13)]. The postoperative FLACC scores at 4, 6, 12, and 24 h were significantly lower (P < 0.05) in the RLB group than in the INB group.

CONCLUSION

Retrolaminar block is superior to ilioinguinal nerve block in providing postoperative analgesia in pediatric patients undergoing unilateral inguinal herniotomy.

Caudal analgesia versus abdominal wall blocks for pediatric genitourinary surgery: systematic review and meta-analysis

Background

Caudal block is a well-established technique for providing perioperative analgesia in pediatric genitourinary surgery, but abdominal wall blocks such as ilioinguinal–iliohypogastric (II-IH) and transversus abdominis plane (TAP) block are increasingly being used.

Methods

Our protocol for this meta-analysis was registered on PROSPERO (CRD42020163497). Central, CINAHL, Embase, Global Health, LILACS, MEDLINE, Scopus and Web of Science were searched from inception to 11 December 2019 for randomized controlled trials that included pediatric patients having genitourinary surgery with II-IH or TAP block as the intervention and caudal analgesia as the comparator. For continuous and dichotomous outcomes, respectively, we calculated the mean difference using the inverse-variance method and the risk ratio with the Mantel-Haenzel method.

Results

In all, 23 trials with 1399 patients were included. II-IH and TAP block were similar to caudal analgesia in the coprimary outcomes of the postoperative pain score at 0–2 hours (high-quality evidence) and the need for in-hospital rescue analgesia (moderate-quality evidence consequent to downgrading by publication bias). No subgroup differences in regard to the type of abdominal wall block or the method of block localization were demonstrated for these primary outcomes. Relative to caudal analgesia, II-IH and TAP block reduced the incidence of postoperative motor blockade and the time to micturition.

Conclusions

This meta-analysis was limited by unclear risk of selection and performance biases and significant heterogeneity. In summary, II-IH and TAP block are a non-invasive and reasonable alternative to caudal analgesia in pediatric genitourinary surgery.

Comparison of Efficacy of Oral versus Regional Clonidine for Postoperative Analgesia following Ilioinguinal/iliohypogastric Block in Children: A Prospective, Randomized, Double-blinded, Placebo-controlled Study

Background:

Clonidine improves quality and prolongs the duration of analgesia in ilioinguinal/iliohypogastric nerve block when given along with local anesthetic and as well as premedication. The objective of this study was to compare the efficacy of oral and regional clonidine for postoperative analgesia in pediatric population after ilioinguinal/iliohypogastric block.

Materials and Methods:

Sixty children aged between 1 and 8 years scheduled for elective hernia surgery were randomly allocated to three groups. Group I received oral midazolam and regional bupivacaine, Group II received oral midazolam with oral clonidine and regional bupivacaine, and Group III received oral midazolam and regional clonidine with bupivacaine. Preoperative sedation and separation score and postoperative duration and quality of analgesia, analgesic need, sedation score, and side effects of clonidine were assessed up to 6 h, postoperatively.

Results:

Duration of analgesia was prolonged in Group II (2.83 ± 2.01 h) and Group III (4.43 ± 2.29 h) compared to Group I (3.98 ± 2.58 h), but the difference was not statistically significant (P = 0.161). Analgesic requirement was comparable between all the groups intraoperatively (P = 0.708) and postoperatively (P = 0.644). Group II had better parental separation (P < 0.001) and sedation score (P < 0.001) compared to Group I and III. Postoperatively, patients of Group II and III were more sedated compared to Group I up to 120 min. Adverse effects of clonidine were equally distributed in all the groups.

Conclusion:

Both oral and regional clonidine was equally efficacious in prolongation of duration and quality of analgesia. Oral clonidine produces better preoperative sedation and parenteral separation which is an added advantage in pediatric population.

Adjuncts should always be used in pediatric regional anesthesia

A number of different adjuncts to local anesthetics can be used to prolong and optimize postoperative pain relief following regional anesthesia in children. The present text provides a slightly opinionated but evidence-based argument in favor of this practice.

A systematic review and meta-analysis of caudal block as compared to noncaudal regional techniques for inguinal surgeries in children

This systematic review and meta-analysis were designed to compare the analgesic effectiveness and adverse effects with the use of caudal analgesia as compared to noncaudal regional analgesia techniques in children undergoing inguinal surgeries. MEDLINE, EMBASE, and CENTRAL (Cochrane) databases were searched for randomized control trials published in English language from 1946 up to 2013. Use of rescue analgesia and adverse effects were considered as primary and secondary outcomes, respectively. Outcomes were pooled using random effects model and reported as risk ratio (RR) with 95% CI. Out of 3240 hits and 24 reports for final selection, 17 were included in this review. Caudal analgesia was found to be better in both early (RR = 0.81 [0.66, 0.99], P = 0.04) and late (RR = 0.81 [0.69, 0.96], P = 0.01) periods, but with a significant risk of motor block and urinary retention. According to GRADE, the quality of evidence was moderate. Although potentially superior, caudal analgesia increases the chance of motor block and urinary retention. There are limited studies to demonstrate that the technical superiority using ultrasound translates into better clinical success with the inguinal nerve blocks.

Adjuvants in pediatric regional anesthesia

SUMMARY Local anesthetics have a limited duration of action. Adjuvants are used to prolong the duration of action and to augment analgesia allowing lower concentrations of local anesthetic to be used. Adjuvants have been used more extensively with neuraxial blocks, particularly caudal epidural blocks, but more recently to supplement peripheral nerve blocks. Intrathecal adjuvants are not covered in this review since spinal anesthesia is not widely used in children except in ex-premature infants. Morphine is the historical gold-standard with which other adjuvants are compared. Clonidine is most useful and is becoming increasingly popular, while the side-effect profile of other agents reduces their utility. Concerns with regard to the neurotoxicity of ketamine in animal models has led to its withdrawal in some countries.

A systematic review and meta-analysis of caudal blockade versus alternative analgesic strategies for pediatric inguinal hernia repair

BACKGROUND

The optimal analgesic strategy for pediatric inguinal hernia repair (IHR) remains undefined. We evaluated the available evidence comparing caudal blockade to alternative analgesic strategies in achieving post-operative analgesia.

METHODS

A systematic review of prospective studies comparing analgesic practices for open unilateral pediatric IHR was performed by searching Medline, Embase, and the Cochrane library from 1950-2011. Articles were critically appraised and included if adequate description of experimental (caudal) and control (nerve blockade or wound infiltration) groups were performed. Pain scores were standardized and evaluated 1 hour after procedure as was the need for rescue analgesia using REVMAN.

RESULTS

Three hundred and seventy articles were identified via our search strategy, thirteen of which were included for analysis. Articles identified were all single-institution, generally small (mean N=29 subjects/arm) and of poor quality (median Jadad score: 2). There was no significant difference in pain scores (-0.09, 95% CI: -0.32, 0.13, p=0.41) or the need for rescue analgesia (0.80, 95% CI: 0.56, 1.13, p=0.46).

CONCLUSION

There is no demonstrable difference in post-operative pain scores or rescue analgesia when comparing caudal blockade with alternative pain management strategies after pediatric IHR. This equipoise suggests that caudal blockade may be obviated for lower risk and less time-consuming maneuvers in patients barring supplementary indications for pain control.

Comparison of caudal analgesia between ropivacaine and ropivacaine with clonidine in children: A randomized controlled trial

Background:

Addition of clonidine to ropivacaine (0.2%) can potentially enhance analgesia without producing prolonged motor blockade. The aim of the present study was to compare the post-operative pain relieving quality of ropivacaine 0.2% and clonidine mixture to that of plain ropivacaine 0.2% following caudal administration in children.

Methods:

In a prospective, double-blinded, randomized controlled trial, 30 ASA 1 pediatric patients undergoing infraumbilical surgery were randomly allocated to receive a caudal injection of either plain ropivacaine 0.2% (1 ml/kg) (group A) or a mixture of ropivacaine 0.2% (1 ml/kg) with clonidine 2 μg/kg (group B). Objective pain score and need for supplemental analgesics were compared during the 1^st 24 hours postoperatively. Residual post-operative sedation and motor blockade were also assessed.

Results:

Significantly prolonged duration of post-operative analgesia was observed in group B (P<0.0001). Heart rate and blood pressure were not different in 2 groups. Neither motor blockade nor post-operative sedation varied significantly between the groups.

Conclusion:

The combination of clonidine (2 μg/kg) and ropivacaine 0.2% was associated with an improved quality of post-operative analgesia compared to plain 0.2% ropivacaine. The improved analgesic quality of the clonidine-ropivacaine mixture was achieved without causing any significant degree of post-operative sedation or prolongation of motor blockade.

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.

Sciatic lateral popliteal block with clonidine alone or clonidine plus 0.2% ropivacaine: effect on the intra-and postoperative analgesia for lower extremity surgery in children: a randomized prospective controlled study

BACKGROUND

The effect of adding clonidine to local anesthetics for nerve or plexus blocks remains unclear. Most of the studies in adults have demonstrated the positive effects of clonidine on intra- and postoperative analgesia when used as an adjunctive agent or in some cases as a single to regional techniques. In the pediatric population, there are only few trials involving clonidine as an adjunct to regional anesthesia, and the analgesic benefits are not definite in this group of patients. The evidence concerning perineural administration of clonidine is so far inconclusive in children, as different types and volume of local anesthetic agents have been used in these studies. Moreover, the efficacy of regional anesthesia is largely affected by the operator's technique, accuracy and severity of operation.

METHODS

The use of clonidine alone or combined with 0.2% ropivacaine for effective analgesia after mild to moderate painful foot surgery was assessed in 66 children, after combined sciatic lateral popliteal block (SLPB) plus femoral block. The patients were randomly assigned into three groups to receive placebo, clonidine, and clonidine plus ropivacaine. Time to first analgesic request in the groups was analyzed by using Kaplan-Meier and the log-rank test (mean time, median time, 95% CI).

RESULTS

In our study, clonidine administered alone in the SLPB seems promising, maintaining intraoperatively the hemodynamic parameters SAP, DAP, HR to the lower normal values so that no patient needed nalbuphine under 0.6 MAC sevoflurane anesthesia, and postoperatively without analgesic request for a median time of 6 hours. In addition, clonidine administered as adjuvant enhances ropivacaine's analgesic effect for the first postoperative day in the majority of children (p = 0.001). Clonidine and clonidine plus ropivacaine groups also didn't demonstrate PONV, motor blockade, and moreover, the parents of children expressed their satisfaction with the excellent perioperative management of their children, with satisfaction score 9.74 ± 0.45 and 9.73 ± 0.70 respectively. On the contrary all the patients in the control group required rescue nalbuphine in the recovery room, and postoperatively, along with high incidence of PONV, and the parents of children reported a low satisfaction score (7.50 ± 0.70).

CONCLUSIONS

Clonidine appears promising more as an adjuvant in 0.2% ropivacaine and less than alone in the SLPB plus femoral block in children undergoing mild to moderate painful foot surgery, with no side effects.

TRIAL REGISTRATION

ClinicalTrials.gov, ISRCTN90832436, (ref: CCT-NAPN-20886).

An evaluation of intrathecal bupivacaine combined with intrathecal or intravenous clonidine in children undergoing orthopedic surgery: a randomized double-blinded study

BACKGROUND

Propofol is a popular agent for providing intraoperative sedation in pediatric population during lumbar puncture and spinal anesthesia. Adjuvant-like clonidine is used increasingly in pediatric anesthesia to provide postoperative analgesia with a local anesthetic agent. The aim of this study was to assess the effects of intrathecal and intravenous clonidine on postoperative analgesia/sedation and intraoperative requirements of propofol after intrathecal bupivacaine for orthopedic surgery in children.

METHODS

Fifty-nine ASA I and II children aged 6-8 year undergoing orthopedic surgery were randomized to receive intrathecal 0.5% bupivacaine 0.2-0.4 mg·kg(-1) and intravenous 2 ml saline (Group B), intrathecal 0.5% bupivacaine 0.2-0.4 mg·kg(-1) plus 1 μg·kg(-1) clonidine and intravenous 2 ml saline (Group BCit), and 0.5% bupivacaine 0.2-0.4 mg·kg(-1) and intravenous 1 μg·kg(-1) clonidine in 2 ml of saline (Group BCiv). Intraoperative sedation was maintained with 20-50 μg·kg(-1)·min(-1) of propofol infusion. The requirements of propofol, time to first rescue analgesia, and postoperative pain or sedation scores were assessed. The duration of motor and sensory blocks and perioperative adverse events were determined.

RESULTS

Clonidine significantly prolonged the time to first rescue analgesia and reduced the requirements of propofol sedation whether administered intravenously or intrathecally. The mean Children and Infants Postoperative Pain Scale scores of children were significantly lower in groups BCit and BCiv than in group B. Postoperative sedation scores were higher in groups BCit and BCiv than in group B. Intrathecal clonidine significantly prolonged the time to regression of the sensory block and recovery of motor block. There were no significant differences among the three groups regarding the incidence of perioperative adverse events.

CONCLUSION

Intrathecal or intravenous clonidine similarly provided better postoperative analgesia and sedation and reduced the requirements of propofol. Only intrathecal clonidine prolonged the duration of sensory and motor blocks.

A Comparison of Single-Dose Caudal Clonidine, Morphine, or Hydromorphone Combined with Ropivacaine in Pediatric Patients Undergoing Ureteral Reimplantation

BACKGROUND

Caudal blockade is a common technique for pediatric postoperative analgesia. While safe and effective, caudal opioids are associated with troublesome side effects. Caudal clonidine may offer significant analgesic benefits. We prospectively compared the analgesic, side effect, and rehabilitation profiles of caudal clonidine, hydromorphone, or morphine in a group of 60 pediatric patients undergoing ureteral reimplantation.

METHODS

Patients aged 6 mo to 6 yr were evenly and randomly enrolled in a double-blind manner. Patients received a single caudal dose of 2 mcg/kg of clonidine, 10 mcg/kg of hydromorphone, or 50 mcg/kg of morphine, combined with 1.0 mL/kg of 0.2% ropivacaine with epinephrine. After sevoflurane in oxygen/air anesthesia, all subjects received proxy nurse-controlled analgesia with morphine. Postoperative pain intensity, use of IV morphine, and side effects were assessed during the first 24 h. Oral intake and discharge home were recorded.

RESULTS

Caudal clonidine resulted in less postoperative nausea and vomiting (P = 0.01) and pruritus (P = 0.007) than did caudal hydromorphone or caudal morphine. Caudal morphine produced more sustained initial analgesia than did caudal clonidine (P = 0.02). No difference was observed in pain scores, total morphine use, time to first oral intake or discharge home. No postoperative respiratory depression, excessive sedation, hypotension, or bradycardia was identified.

CONCLUSIONS

Although caudal morphine may result in more sustained initial analgesia, caudal clonidine combined with nurse-controlled analgesia appears to provide comparable analgesia with fewer side effects. Based on these results, the use of caudal clonidine may be superior to caudal opioids after pediatric ureteral reimplantation.

Characterization of spinal alpha-adrenergic modulation of nociceptive transmission and hyperalgesia throughout postnatal development in rats

BACKGROUND AND PURPOSE

The selective alpha(2)-adrenergic agonist dexmedetomidine is used clinically for analgesia and sedation, but effects in early life are not well characterized. Investigation of age-related effects of dexmedetomidine is important for evaluating responses to exogenously administered analgesics and provides insight into postnatal function of noradrenergic pathways.

EXPERIMENTAL APPROACH

We examined effects of epidural dexmedetomidine in anaesthetized rat pups (3, 10 and 21 postnatal days) using a quantitative model of nociception and C-fibre induced hyperalgesia. Electromyographic recordings of withdrawal responses to hindpaw mechanical stimuli measured effects of dexmedetomidine upon the baseline reflex and the response to mustard oil application on the hindpaw (primary hyperalgesia) or hindlimb (secondary hyperalgesia). In addition, we compared epidural with systemic administration, examined effects of spinal transection and evaluated heart rate changes following dexmedetomidine.

KEY RESULTS

Epidural dexmedetomidine dose-dependently prevented mustard oil-induced hyperalgesia at all ages but dose requirements were lower in the youngest pups. Higher doses also suppressed the baseline nociceptive reflex when given epidurally, but had no effect when given systemically. Analgesic efficacy was the same for primary and secondary hyperalgesia, and was not diminished by spinal cord transection.

CONCLUSIONS AND IMPLICATIONS

Our laboratory studies predict that spinally mediated alpha(2)-agonist analgesia would be effective throughout postnatal development, dose requirements would be lower in early life and selective anti-hyperalgesic effects could be achieved with epidural administration at doses lower than associated with antinociceptive or cardiovascular effects. Clinical trials of alpha(2) agonists in neonates and infants should consider developmentally regulated changes.

Paediatric day-case anaesthesia and pain control

PURPOSE OF REVIEW

More surgery on children is being carried out on a day-case basis and we review the anaesthetic management. Selection of appropriate patients and procedures is vital and careful preparation of children and families minimizes fear and anxiety and streamlines the organizational aspects of care. Simple, noninvasive general-anaesthetic techniques with modern agents are recommended. Good analgesia is important and is based upon local or regional blockade, nonsteroidal antiinflammatory drugs and paracetamol, with opioids being reserved for rescue analgesia. Omission of opioids helps to minimize postoperative emesis. Discharge home is facilitated by clear instructions about activities, dressings, wound care and continuing pain control.

RECENT FINDINGS

Oral clonidine premedication, new, safer local anaesthetic agents, ultrasound guidance for blocks and prolongation of single-injection caudal blocks with clonidine or ketamine are recent developments. Guidelines for safe sedation and analgesia for procedures are available. Behavioural and cognitive changes can be seen in children after anaesthesia and surgery and parents should be informed of this possibility.

SUMMARY

Children benefit particularly from day care and recent advances in anaesthesia and pain management have allowed a huge expansion of this modality of care with a consequent reduction in the need for children to be in hospital.

A comparison of nerve stimulator guided paravertebral block and ilio-inguinal nerve block for analgesia after inguinal herniorrhaphy in children

The aim of this study was to compare the efficacy of nerve stimulator guided paravertebral block with ilio-inguinal nerve block in children undergoing inguinal herniorrhaphy. Eighty children were randomly allocated to receive either paravertebral block or ilio-inguinal nerve block. Each block was evaluated in terms of intra-operative haemodynamic stability, postoperative pain scores at rest, on movement and during activity, requirement for supplemental analgesia and parental satisfaction. Haemodynamic stability was maintained significantly better during sac traction in the paravertebral block group (p < 0.005). Pain scores and analgesic consumption were significantly lower in the paravertebral block group during the postoperative follow-up period (p < 0.05). Parental satisfaction (93%vs 69%) and surgeon satisfaction (93%vs 64%) were significantly higher in the paravertebral block group (p < 0.05). Paravertebral blockade improved and prolonged postoperative analgesia, and was associated with greater parental and surgeon satisfaction when compared to ilio-inguinal nerve block.

Clonidine administered as adjuvant for bupivacaine in ilioinguinal-iliohypogastric nerve block does not prolong postoperative analgesia

BACKGROUND

Coadministration of clonidine with local anesthetics is associated with improvement of the quality of peripheral nerve block and significant prolongation of postoperative analgesia. Better analgesia has been reported with clonidine in ilioinguinal nerve block compared with caudal use. The object of this study was to determine whether adding of 1 microg.kg(-1) clonidine to bupivacaine 0.25% in ilioinguinal-iliohypogastric nerve block prolongs postoperative analgesia in children.

METHODS

Ninety-eight children ASA I-II aged between 1 and 12 years, scheduled for elective outpatient herniorrhaphy or orchidopexy were randomly allocated to receive an ilioinguinal-iliohypogastric nerve block either with 0.3 ml.kg(-1) bupivacaine 0.25% plus 1 microg.kg(-1) clonidine or only bupivacaine. Postoperative analgesic needs, time to the first analgesic supplementation and sedation score were assessed in hospital for 6 h postoperatively and at home by telephone call.

RESULTS

Demographic data were similar in both groups. There was no statistical difference in the rate of rescue analgesia between the two groups during the first six postoperative hours (20.4% group clonidine vs 30.6% group no clonidine) (P = 0.17). A slight decrease in systolic blood pressure during surgery was reported in the clonidine group. There was no difference in the scores of sedation between the two groups. At home, 10 patients in the clonidine group and nine patients in the nonclonidine group received analgesic medication. There was no difference between the two groups regarding the number of patients receiving analgesic rescue during the first 24 h (log rank = 0.39). Parental satisfaction was high in both groups.

CONCLUSIONS

Our study failed to demonstrate any advantage in addition of 1 microg.kg(-1) clonidine to 0.25% bupivacaine for ilioinguinal-iliohypogastric nerve block compared with bupivacaine 0.25% alone.

Caudal bupivacaine supplemented with caudal or intravenous clonidine in children undergoing hypospadias repair: a double-blind study

BACKGROUND

Clonidine is used increasingly in paediatric anaesthetic practice to prolong the duration of action of caudal block with a local anaesthetic agent. Which route of administration of clonidine is the most beneficial remains unknown. We compared the effects of caudal and i.v. clonidine on postoperative analgesia produced by caudal bupivacaine after hypospadias repair.

METHODS

Forty-six children (ASA I or II) aged 24-104 months received standardized premedication with midazolam, a general anaesthetic and a caudal block with bupivacaine 0.25%, 0.5 ml kg(-1). The children were randomized in a double-blind fashion to two groups: the i.v. group received clonidine 2 micro g kg(-1) i.v. and simultaneously the same volume of saline caudally. The caudal group received clonidine 2 micro g kg(-1) caudally and a similar volume of saline i.v. After surgery, all children received acetaminophen 20 mg kg(-1) rectally or orally 6-hourly and were given a patient-controlled or nurse-controlled analgesia (PCA/NCA) pump with i.v. morphine (bolus of 25 micro g kg(-1) and an 8-min lockout period with no background infusion). Monitoring of scores for pain, sedation, motor block, and postoperative nausea and vomiting was performed by nurses blinded to the study allocations. Time to first activation of the PCA/NCA pump and 0-24 h and 24-48 h morphine consumption were also recorded.

RESULTS

Forty-four children completed the study. Age, weight and duration of anaesthesia and surgery were similar in the two groups. The median (range) time to first activation of the PCA/NCA pump was similar in the two groups: 425 (150-1440) min in the i.v. group and 450 (130-1440) min in the caudal group. The number of children not requiring postoperative morphine was four and seven respectively. Morphine consumption during 0-24 h and 24-48 h was similar between groups.

CONCLUSIONS

The analgesic effect of clonidine 2 micro g kg(-1) as an adjunct to caudal block with bupivacaine 0.25%, 0.5 ml kg(-1) is similar whether administered i.v. or caudally.

A long-term continuous infusion via a sciatic catheter in a 3-year-old boy

We describe the case of a 3-year-old boy with a subtotal amputation of the right foot who received treatment for pain via a peripheral catheter positioned at the level of the sciatic nerve (lateral approach).We administered a continuous infusion of 0.2% ropivacaine, 0.4 mg x kg(-1) x h(-1) plus clonidine 0.12 microg x kg(-1) x h(-1) for 21 days. Pain relief was complete and the patient did not require any further rescue analgesia throughout the period even during medications and surgical treatment in our intensive care unit. We discuss the safety and efficacy of the use of a peripheral continuous infusion in children compared with other techniques of analgesia.

Ropivacaine in infants and children

PURPOSE OF REVIEW

Ropivacaine is considered less toxic than bupivacaine. In addition, at the low concentrations used for providing postoperative analgesia, ropivacaine seems to produce less motor blockade than bupivacaine. These two properties are of particular interest in paediatric practice.

RECENT FINDINGS

In paediatric practice regional anaesthesia is usually performed under general anaesthesia, and postoperative analgesia was until recently the major concern for most practitioners. The question now is: what is the right concentration to provide adequate intraoperative anaesthesia when ropivacaine is used in combination with volatile anaesthetic agents? The low concentration of ropivacaine used for postoperative analgesia seems to provide adequate intraoperative anaesthesia when general anaesthesia with a 0.5 minimum concentration of volatile anaesthetic is used in combination. However, potential toxicity is still the subject of debate because ropivacaine clearance is low in infancy and early childhood. Ropivacaine has a longer absorption process than bupivacaine, which leads to a lower maximum peak concentration with ropivacaine than with bupivacaine either after central or peripheral blocks, thus increasing the safety of the drug. The addition of adjuvant drugs also permits lower concentrations of ropivacaine, while providing excellent analgesia. The addition of adrenaline at very low concentrations has recently been found to increase the quality of epidural analgesia.

SUMMARY

Ropivacaine is now the reference drug for regional anaesthesia in paediatric patients, mainly because it is considered less toxic than bupivacaine and provides excellent postoperative analgesia even when used at low concentrations.