Comparison of fentanyl-bupivacaine or midazolam-bupivacaine mixtures with plain bupivacaine for caudal anaesthesia in children

Comparison of adjuvant pharmaceuticals for caudal block in pediatric lower abdominal and urological surgeries: A network meta-analysis

STUDY OBJECTIVE

Caudal block helps relieve pain after sub-umbilical surgery in pediatric patients; however, the duration for which it exerts its analgesic effect is limited. The addition of certain adjuvant agents to local anesthetics (LAs) that are used to administer caudal block can prolong postoperative analgesia. Therefore, we aimed to compare the efficiencies and side effects of caudal adjuvants in the settings of pediatric lower abdominal and urological surgeries.

DESIGN

A network meta-analysis (NMA).

PATIENTS

One hundred and twelve randomized controlled trials (RCTs) involving 6800 pediatric patients were included in the final analysis.

INTERVENTIONS

Different adjuvant agents, namely clonidine, dexamethasone, dexmedetomidine, fentanyl, ketamine, magnesium, midazolam, morphine, neostigmine, and tramadol.

MEASUREMENTS

The primary outcome was the duration of analgesia. The secondary outcomes included the requirement for additional analgesia, analgesic consumption, and postoperative complications. The effects and rankings were evaluated using NMA and the surface under the cumulative ranking curve scores, respectively.

RESULTS

Neostigmine, dexmedetomidine, and dexamethasone were found to be the three most effective adjuvants that prolong the duration of analgesia for caudal block, and these adjuvants extended this duration by 8.9 h (95% confidence interval [CI], 7.1-10.7), 7.3 h (95% CI, 6.0-8.6), and 5.9 h (95% CI, 4.0-7.7), respectively. Caudal neostigmine was associated with an increase in the incidence of postoperative nausea and vomiting, whereas dexmedetomidine and dexamethasone showed no postoperative complications.

CONCLUSIONS

This NMA provided evidence and suggested that dexmedetomidine and dexamethasone may be the most beneficial adjuvant pharmaceutics adding to LAs for caudal block in children. However, given the off-label status of caudal dexmedetomidine and dexamethasone, further high-quality RCTs are still warranted, especially to determine whether delayed neurological complications will occur.

Efficacy of Adding Midazolam to Bupivacaine for Transversus Abdominis Plane Block on Postoperative Analgesia after Hysterectomy: A Randomized Controlled Study

Background and Aim:

Different adjuncts have been utilized to promote the quality and prolong the duration of local anesthetics for a variety of regional block techniques. This study aimed to assess the effects of midazolam coadministered with bupivacaine in transversus abdominis plane (TAP) block on the 24-h morphine consumption, the postoperative analgesia duration and adverse effects.

Settings and Design:

A prospective, randomized, controlled double-blind trial that was carried out at a university hospital.

Patients and Methods:

Eighty-two females subjected to open total abdominal hysterectomy under general anesthesia were involved in this trial. Participants were allocated randomly to either of two groups (41 each). Control group: received TAP block with 20 mL of 0.25% bupivacaine or midazolam group: received TAP block using the same volume of bupivacaine plus 50 μg/kg midazolam/side. Postoperative cumulative 24-h morphine consumption, analgesia duration, pain score, sedation score, and adverse events were recorded.

Statistical Analysis:

Student's t-test, Mann–Whitney U-test, and Chi-square test were used.

Results:

Patients in the midazolam group had a lower cumulative 24-h morphine consumption [median doses (interquartile range): 15 (10–19.50) mg compared to 25 (17.50–37) mg, P < 0.001], lower postoperative pain score at rest at the 4^th, 6^th, and 12^th h (P = 0.01, 0.02, and 0.02, respectively) and on movement at 2, 4, 6, and 12 h (P < 0.001), longer time till the first postoperative demand for rescue analgesia (430.11 ± 63.02 min) compared to 327.78 ± 61.99 min (P < 0.001), and less sedation, nausea and/or vomiting, and pruritus.

Conclusions:

Adding midazolam as a bupivacaine adjuvant for TAP block reduces the 24-h morphine consumption, extends the postoperative analgesia duration, and decreases the incidence of adverse effects following abdominal hysterectomy.

A randomized-controlled, double-blind study to evaluate the efficacy of caudal midazolam, ketamine and neostigmine as adjuvants to bupivacaine on postoperative analgesic in children undergoing lower abdominal surgery

Background: Caudal epidural is the most commonly used technique for the management of postoperative pain in children. The aim of the present study was to assess and compare the efficacy of caudal bupivacaine as a postoperative analgesic alone or combined with midazolam, ketamine, and neostigmine in pediatric patients undergoing lower abdominal surgery. Methods: Eighty pediatric patients categorized under the American Society of Anesthesiologists Physical Status I and II Classification System, who have been scheduled to undergo lower abdominal surgery were randomly designated into four groups to receive caudal block with either 1 ml/kg of 0.25% caudal bupivacaine for group B, 1 ml/kg of 0.25% caudal bupivacaine mixed with 2 μg/kg neostigmine for group BN, 1 ml/kg of 0.25% caudal bupivacaine mixed with 0.5 mg/kg ketamine for group BK or 1 ml/kg of 0.25% caudal bupivacaine mixed with 50 mcg/kg midazolam for group BM. Postoperative analgesia was examined by a blinded anesthetist utilizing a Revised Faces Pain Scale. Consumption of the total amount of rescue analgesic each 24 h, postoperative time to requirement of the first dose and any adverse effects were noted. Results: The four groups were comparable as regards age, sex, weight, duration of surgery, heart rate, blood pressure and the time from induction of anesthesia to response to voice. The Revised Faces Pain Scale was 2.6±1.5 in group BN, 3.1±1.8 in group BM, 4.4±2.4 in group BK, and 5.6±1.3 in group B (p=0.005). Postoperative duration of analgesia was 433±68 min, 769±118 min, 1097±126 min and 1254±176 min in groups B, BK, BM and BN respectively (P=0.001). The dose of rescue analgesic within 24 h in group B was significantly higher than those of the other three groups (P<0.05). Conclusion: Addition of either neostigmine, midazolam, or ketamine to caudal bupivacaine extended analgesia time and decreased rescue analgesic compared to bupivacaine alone in children who underwent lower abdominal surgery. (www.actabiomedica.it)

Effect of adding midazolam to bupivacaine during rectus sheath block: a randomised controlled trial

BACKGROUND

Various adjuvants have been tried to improve quality and increase duration of local anaesthetics during various nerve blocks. We aimed to evaluate the effect of adding midazolam to bupivacaine on rectus sheath (RS) block in patients undergoing umbilical or epigastric hernia repair.

METHODS

In all, 60 adult patients were divided into two equal groups, each group included 30 patients. Group I received 20 ml of bupivacaine hydrochloride 0.25% + midazolam 50 μg/kg in 2 ml saline 0.9% (Midazolam group, n = 30), whereas Group II received 20 ml of bupivacaine hydrochloride 0.25% + 2 ml saline (Control group, n = 30) for RS block on each side. The primary outcome was post-operative 48 h morphine consumption, whereas secondary outcomes included analgesia duration, post-operative pain, as evaluated by visual analogue scale (VAS) for pain scoring at 1, 2, 6, 12, 24 and 48 h post-operatively, reported post-operative nausea and or vomiting (PONV), somnolence or any adverse drug reactions.

RESULTS

The current study showed that addition of midazolam to bupivacaine for RS blockade provided good analgesia as evidenced by a statistically significant less morphine consumption in the post-operative 48 h [11.2 (5.3-18.3) vs. 25.9 (15.2-31.0) mg, P = 0.002], longer duration of analgesia, lower VAS during post-operative 48 h, lower incidence of PONV, somnolence and pruritus.

CONCLUSION

Midazolam addition to bupivacaine for RS blockade provided adjuvant analgesia as supported by less morphine consumption, longer duration of analgesia, and lower VAS score.

Effect of Addition of Fentanyl and Clonidine to Local Anesthetic Solution in Peribulbar Block

Objective:

To compare the effect of addition of fentanyl and clonidine as adjuvants to bupivacaine and lignocaine in peribulbar block.

Methods:

The study was conducted on 105 adult patients of either sex, of ASA grade I and II undergoing ophthalmic surgeries. Patients were randomly divided into 3 groups of 35 each. All the patients were given peribulbuar block with 5ml lignocaine 2% +3 ml bupivacaine 0.5% +1 ml hyaluronidase (250 IU). In addition to this 1 ml normal saline was added to Group S, 25 μg fentanyl to Group F and 25 μg clonidine to Group C. Onset and duration of globe and lid akinesia, duration of sensory blockage and analgesia, hemodynamic parameters, number of rescue analgesic and visual analogue score were recorded.

Results:

The mean time of onset of globe and lid akinesia was significantly faster in group F and group C compared to group S, mean duration of globe and lid akinesia was longer in Group F (207.71 + 13.54 and 143.14 + 7.86 min) and group C (213.52 + 14.52 and 162.06 + 17.1 min) compared to group S (117.78 + 10.42 and 87.64 + 9.76 min). The mean duration of analgesia was significantly longer in group F (217.71 + 12.67) and C (258.82 + 14.50 min) as compared to group S (131.39 + 9.63 min).

Conclusion:

Addition of fentanyl or clonidine as adjuvant to local anaesthetic in peribulbar block provides faster onset and prolonged analgesia compared to local anaesthetic alone.

Treatment of Postoperative Pain in Pediatric Operations: Comparing the Efficiency of Bupivacaine, Bupivacaine-Dexmedetomidine and Bupivacaine-Fentanyl for Caudal Block

BACKGROUND

Caudal analgesia is a common method for postoperative pain management in pediatric patients. Additive agents such as opioids and α₂ agonists have been used to enhance the analgesic effects of local anesthetics for caudal block.

OBJECTIVES

The aim of this study was to compare the additive effects of dexmedetomidine and fentanyl on bupivacaine-induced caudal analgesia in pediatric patients who had undergone elective inguinal hernia repair.

METHODS

This randomized, double-blind clinical trial included children aged 1 - 5 years who were divided into three groups: the bupivacaine group (Group B) received 0.25% bupivacaine (1 ml/kg), the bupivacaine-dexmedetomidine group (Group BD) received 0.25% bupivacaine (1 mL/kg) plus 2 µg/kg dexmedetomidine, and the bupivacaine-fentanyl group (Group BF) received 0.25% bupivacaine (1 mL/kg) plus 2 µg/kg fentanyl. The hemodynamic variables (heart rate, systolic blood pressure, respiratory rate, and peripheral arterial oxygen saturation) were measured perioperatively. Pain, sedation and motor block scores and adverse events (nausea and vomiting, pruritis, hypotension, bradycardia, urinary retention and respiratory depression) were documented at 30 and 60 minutes, and the 1st, 2nd, 4th, 6th, 12th and 24th hours after the operation. The other recordings include the duration of surgery and analgesic requirement.

RESULTS

A total of 61 patients were analyzed. The lowest pain scores were found in the BD group at all time points (P < 0.001). The sedation scores were higher in the BD group than in the other two groups at all time points (P < 0.001). No motor block was observed after the operation. Only three patients required analgesic administration 2 to 6 hours after the operation in group B. No side effects were observed in any of the groups, and there was no significant difference in the duration of surgery among the three groups.

CONCLUSIONS

The results show that the analgesic and sedative effects were better when dexmedetomidine was added to bupivacaine than when fentanyl was added or bupivacaine alone was administered in the pediatric population studied here that underwent elective inguinal hernia repair.

The success rate and complications of awake caudal epidural bupivacaine alone or in combination with intravenous midazolam and ketamine in pre-term infants

BACKGROUND

The aim of the present study is to compare the success rate and complications of caudal epidural bupivacaine alone or in combination with intravenous (IV) midazolam and ketamine in awake infants undergoing lower abdominal surgery.

MATERIALS AND METHODS

In this double-blind, clinical trial study, 90 infants (aged below 3 months and weight below 5 kg) with American Society of Anaesthesiologists I-II, were divided into three groups of each 30: Group 1 received bupivacaine 0.25%, 1 mL/kg for caudal epidural block; Groups 2 and 3 received caudal block with same dose bupivacaine along with IV pre-treatment with midazolam 0.1 mg/kg or IV midazolam 0.1 mg/kg and ketamine 0.3 mg/kg, respectively.

RESULTS

The success rates in Groups 2 and 3 were 93.3% and 93.1%, respectively, compared with a caudal block with bupivacaine alone 80%; P = 0.015). There was no significant difference among the three groups in terms of mean systolic and diastolic blood pressures and mean heart rate at intervals of 0, 20, 40 and 60 min (P < 0.05). There were no significant differences in the pain scores >3 on the Neonatal Infant Pain Scale at three intervals (30, 60 and 120 min) after surgery among the three groups. The complications such as apnoea or desaturation were not found in any of the studied groups.

CONCLUSIONS

Adding IV ketamine and/or midazolam to bupivacaine caudal epidural block in the conscious infants can positively affect block success rate.

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.

Bayesian enhanced meta-analysis of post-operative analgesic efficacy of additives for caudal analgesia in children

BACKGROUND

The authors calculated the effect size for post-operative analgesia of three additives, clonidine, neostigmine, and tramadol to bupivacaine, ropivacaine, or levobupivacaine used for single-dose caudal extradural blockade in children.

METHODS

A meta-analysis was performed for three end points of efficacy: the increase of time until administration of analgesic drugs, the proportion of patients requiring analgesic drugs during the initial 24 post-operative hours, and the amounts of post-operative analgesic drugs. A Bayesian inference supporting direct statements about the probability of the magnitude of an effect was used to compare the effects size.

RESULTS

Neostigmine increased the duration of analgesia by 9.96 h (95% confidence interval: 7.75 to 12.16), as compared with 3.68 h (2.65 to 4.7) with clonidine and 4.45 (2.84 to 6.07) with tramadol. There is a 95% probability that neostigmine increases the duration of post-operative analgesia by more than 8 h, clonidine by more than 2.8 h, and tramadol by more than 3.25 h, as compared with local anesthetics alone. The odds ratios for the proportion of patients requiring analgesic drugs were 0.22 [0.13 to 0.37] for clonidine and 0.28 [0.10 to 0.75] for neostigmine. With tramadol, there was no statistically significant difference. All three additives reduced the amounts of post-operative analgesic drugs. Neostigmine and tramadol increase the probability for post-operative nausea or vomiting (PONV).

CONCLUSIONS

Neostigmine provides the longest post-operative analgesia. With clonidine, the duration of analgesia is shorter and sedation is increased, but the probability for PONV could be decreased.

Neuraxial analgesia in neonates and infants: a review of clinical and preclinical strategies for the development of safety and efficacy data

Neuraxial drugs provide robust pain control, have the potential to improve outcomes, and are an important component of the perioperative care of children. Opioids or clonidine improves analgesia when added to perioperative epidural infusions; analgesia is significantly prolonged by the addition of clonidine, ketamine, neostigmine, or tramadol to single-shot caudal injections of local anesthetic; and neonatal intrathecal anesthesia/analgesia is increasing in some centers. However, it is difficult to determine the relative risk-benefit of different techniques and drugs without detailed and sensitive data related to analgesia requirements, side effects, and follow-up. Current data related to benefits and complications in neonates and infants are summarized, but variability in current neuraxial drug use reflects the relative lack of high-quality evidence. Recent preclinical reports of adverse effects of general anesthetics on the developing brain have increased awareness of the potential benefit of neuraxial anesthesia/analgesia to avoid or reduce general anesthetic dose requirements. However, the developing spinal cord is also vulnerable to drug-related toxicity, and although there are well-established preclinical models and criteria for assessing spinal cord toxicity in adult animals, until recently there had been no systematic evaluation during early life. Therefore, in the second half of this review, we present preclinical data evaluating age-dependent changes in the pharmacodynamic response to different spinal analgesics, and recent studies evaluating spinal toxicity in specific developmental models. Finally, we advocate use of neuraxial drugs with the widest demonstrable safety margin and suggest minimum standards for preclinical evaluation before adoption of new analgesics or preparations into routine clinical practice.

Effect of intrathecal midazolam in the severity of pain in cesarean section: a randomized controlled trail

BACKGROUND

The benzodiazepines are used primarily for anxiolysis, amnesia and sedation. However, recent investigations have shown that some forms of this group of drugs have also direct effect on pain. This study aims to determine the effect of midazolam in reducing the severity of pain in women scheduled for elective cesarean section.

METHODS

In a prospective, double blind randomized controlled trial, two groups parallel study, was conducted in Imam Reza/Moatazedi Hospital, an affiliate of Kermanshah University of Medical Sciences. Parturient women who met study inclusion criteria were consecutively assigned into either experimental (n=62) or control groups (n=62). Women in the experimental group received bupivacaine (10 mg) plus intrathecal midazolam (2 mg/ml) (BM) and those in the control group received bupivacaine plus normal saline (BNS). The outcome pain severity was measured by Verbal Numerical Rating Scale.

RESULTS

In comparison with the BNS group, mothers in the BM group reported a significant relief in pain (15 min and 120 min) after the surgery. There were no significant differences between the groups regarding the intensity of pain 5, 30, 60 and 240 min after the surgery. The average time until the first dose of additional analgesic, per mother's request was 142.18±55.19 min in the BNS vs 178.06±77.33 min in the BM group.

CONCLUSION

Combination of bupivacaine plus intrathecal midazolam was an effective anesthetic technique to provide improvement in pain. The onset of sedation was faster in the BM group compared with the BNS group. The duration of effective analgesia, and the time for regression of sensory analgesia was the same in both groups in our study. However, incidence of nausea and vomiting was higher in the experimental group.

The addition of fentanyl to 1.5 mg/ml ropivacaine has no advantage for paediatric epidural analgesia

BACKGROUND

Epidural opioids are frequently combined with local anaesthetics for an additive antinociceptive effect. We investigated the efficacy of epidural fentanyl to 1.25 or 1.5 mg/ml ropivacaine for post-operative epidural analgesia in children.

METHODS

One hundred and eight children undergoing hypospadias repair were randomized to receive 1.25 mg/ml ropivacaine (R1.25 group), 1.25 mg/ml ropivacaine with 0.2 mcg/kg/h of fentanyl (R1.25F group), 1.5 mg/ml ropivacaine (R1.5 group) or 1.5 mg/ml ropivacaine with 0.2 mcg/kg/h of fentanyl (R1.5F group) for post-operative epidural analgesia. The epidural catheter was threaded caudally through the L4-5 interspace. The face, legs, activity, cry, consolability (FLACC) score was assessed at every hour and at FLACC score >4, an epidural bolus of 0.5 ml/kg of ropivacaine 1.5 mg/ml was given as the rescue analgesia. The incidence of side effects such as hypoxia, sedation, pruritus, nausea and/or vomiting was recorded.

RESULTS

The need for rescue analgesia was higher in the R1.25 group compared with that in the other three groups (all P<0.05). The incidence of side effects was higher in the R1.5F group compared with that in the R1.25 and R1.5 groups (both P=0.010).

CONCLUSION

The addition of 0.2 mcg/kg/h fentanyl to 1.5 mg/ml ropivacaine increased the incidence of side effects without improvement of analgesia in infants and children undergoing hypospadias repair. The use of plain 1.25 mg/ml ropivacaine increased the need for rescue analgesia and this could be compensated by addition of fentanyl.

Caudal midazolam does not affect sevoflurane requirements and recovery in pediatric day-case hernioplasty

BACKGROUND

This prospective, randomized, double-blind study aimed to determine whether caudal midazolam combined with ropivacaine affects anesthetic requirements, recovery profiles, and post-operative analgesia compared with ropivacaine alone in pediatric day-case hernioplasty.

METHODS

Sixty boys (2-5 years old) received caudal injections of 0.2% ropivacaine 1 ml/kg and epinephrine 1 : 200,000 with (RM group) or without (R group) 50 microg/kg of midazolam under sevoflurane anesthesia. The sevoflurane requirement was determined by adjusting to a bispectral index score=50.

RESULTS

Concentrations of end-tidal sevoflurane (ETsevo%) after induction were similar in both groups. After caudal block, ETsevo% before and after surgical stimuli did not show significant intra- or intergroup differences. Recovery characteristics, including post-operative sedations, were similar in both groups. Post-operative pain scores were significantly lower in the RM group than the R group.

CONCLUSIONS

Caudal midazolam (50 microg/kg) added to 2% ropivacaine did not influence sevoflurane requirement or recovery but improved post-operative analgesia compared with ropivacaine alone in pediatric day-case hernioplasty.

A prospective, double-blind, randomized trial of caudal block using ropivacaine 0.2% with or without fentanyl 1 microg kg-1 in children

BACKGROUND

It has been reported that ropivacaine produces vasoconstriction in contrast to vasodilation produced by bupivacaine. It is possible that additives to ropivacaine can provide further analgesic advantages compared with bupivacaine. We thus evaluated whether the addition of fentanyl to ropivacaine prolonged the duration of analgesia after a single shot caudal block.

METHODS

A total of 36 children undergoing surgical procedures below the umbilicus were randomly allocated to one of two groups: Group F received ropivacaine 0.2%, 1 ml kg(-1) with fentanyl 1 microg kg(-1) and Group S received ropivacaine 0.2%, 1 ml kg(-1) with saline. The analgesic effect of the caudal block was evaluated using the Children's Hospital of Eastern Ontario Pain Scale (CHEOPS) and sedation was assessed using the Steward score at 30 min after extubation and at 1, 2, 4, 6, 12 and 24 h. The first analgesic requirement time and side-effects in a 24 h period were also recorded.

RESULTS

There were no differences in characteristics between the groups. The end-tidal concentration of sevoflurane at extubation in Group F was significantly lower than in Group S. However, there was no significant difference in time from discontinuation of the volatile anaesthetics to tracheal extubation. No statistical differences were found in the CHEOPS and Steward score, and the time to first analgesia. The incidence of postoperative vomiting was not significantly different.

CONCLUSION

We found that the addition of fentanyl 1 mug kg(-1) to ropivacaine 0.2% for caudal analgesia provides no further analgesic advantages over ropivacaine 0.2% alone.

Caudal analgesia and anesthesia techniques in children

PURPOSE OF REVIEW

Caudal epidural blockade remains the cornerstone of pediatric regional anesthesia. In this article we provide a comprehensive review of the recent developments in caudal anesthesia in infants and children.

RECENT FINDINGS

Research has focused on prolonging the duration of single-shot caudal blocks and accurately positioning continuous caudal catheters. New local anesthetics with similar potencies but less toxicity have been introduced. Opioids prolong the duration of analgesia of local anesthetic, but have also been associated with unacceptable side effects, particularly in pediatric outpatients. Various non-opioid adjuncts with more favorable side-effect profiles may increase the duration of analgesia. New ultrasound and nerve-stimulation techniques have been developed to accurately guide epidural catheters to a specific spinal level.

SUMMARY

The addition of ketamine or clonidine to a caudal local anesthetic prolong the duration of the block. However, a preservative-free preparation of ketamine that is suitable for neuraxial use is not widely available. Ultrasound imaging and electrical stimulation are promising options to accurately position a caudal needle. However, because ultrasound imaging is more difficult in older children, nerve stimulation is a more-suitable technique to accurately guide caudal catheters in this patient population. Although complications associated with caudal block are rare, the risks and benefits must be carefully considered on an individual basis.

The use of intrathecal midazolam in humans: a case study of process

Early preclinical work demonstrated the potential role of spinal benzodiazepine pharmacology in regulating spinal nociceptive transmission. We review this preclinical activity and the evolving implementation of intrathecal midazolam in humans for pain management. Important elements in this development for use in humans are issues pertinent to safety and the preclinical reports that have increased our understanding of intrathecal midazolam toxicity. We seek to emphasize the time course of these studies and how they merged to provide enabling data that drove the clinical implementation. In the case of midazolam, we point to the potential issues that arose when preclinical safety data were unreasonably ignored and how consideration of preclinical safety data can serve to facilitate drug development by demonstrating reasonable safety profiles that document the minimal degree of potential risk to the patient. Issues that are of continuing relevance to the use of intrathecal midazolam, including issues of formulation and kinetics, are considered.

IMPLICATIONS

The intrathecal use of midazolam has evolved over 20 years though a combination of preclinical and clinical investigations. We review the time course of this development to define critical elements that should be pursued in reducing the risk associated with the clinical use of a novel spinal drug.

Recent developments in paediatric regional anaesthesia

PURPOSE OF REVIEW

This review will focus on recently published data concerning side effects and complications of paediatric regional anaesthesia, putting into perspective the currently used techniques.

RECENT FINDINGS

Penile block is clearly a technique with a very large benefit and minimal side effects. Ilioinguinal nerve block, on the other hand, quite commonly leads to complications. Single-shot caudal anaesthesia is considered a safe and effective technique; however, even with this widely used block, complications such as sacral osteomyelitis can occur. Recent review articles have focussed on the role of additives for prolonging the duration of paediatric caudal anaesthesia. The use of ketamine or s-ketamine as an additive appears to be most promising for the future.

SUMMARY

Paediatric regional anaesthesia is now widely used for postoperative pain relief in children. However, a careful risk-benefit analysis is always mandatory before such medical interventions are undertaken.

Neuraxial blocks for anaesthesia and analgesia in children

PURPOSE OF REVIEW

The use of regional techniques in paediatric anaesthesia has increased dramatically. Our aim is to produce a comprehensive review of the recent literature on neuraxial blockade in infants and children, focusing on three topics: choice of local anaesthetic and adjunct drugs, technical aspects and complications.

RECENT FINDINGS

The current literature shows a trend towards using the single isomers (levobupivacaine or ropivacaine) rather than racemic bupivacaine. In addition, opioids as adjuncts are being challenged by clonidine and ketamine, which have more benign side effects. The spread of radiopaque dye within the epidural space (which may mimic that of local anaesthetic solutions) appears to be highly variable, although distribution is related to the volume injected. Recent techniques (e.g. ultrasound or stimulating catheters) have been developed to accurately identify the position of epidural catheters. In contrast to adults, neuraxial blockade using local anaesthetic solutions is associated with stable cardiovascular variables, even in children with congenital heart disease. Although the incidence of complications associated with paediatric neuraxial blockade is low, the potential risks must always be considered.

SUMMARY

It is likely that the use of epidural ketamine or clonidine as adjuncts to local anaesthetics will grow. Alternatives, such as midazolam, may offer advantages in particular circumstances, although rigorous evaluation of the safety of these solutions when injected along the neuraxis and the development of formulations without preservatives are needed. The use of stimulating caudal catheters or ultrasound-guided techniques appears to offer promising options for the future to more accurately position catheters.