Caudal neostigmine, bupivacaine, and their combination for postoperative pain management after hypospadias surgery 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.

Clonidine as an Additive to Local Anesthetics in Caudal Block for Postoperative Analgesia in Pediatric Surgery: A Systematic Review and Meta-Analysis

Background: Clonidine is an anesthetic with favorable efficacy and safety profiles for caudal epidural block, but comparisons with other adjuvants need to be confirmed in pediatric patients. Aim: To investigate the effects of clonidine as an adjuvant in caudal epidural block to improve the intraoperative and postoperative analgesia in pediatric surgery. Methods: PubMed, Embase, and the Cochrane Library were searched for available papers published up to February 2021. The outcomes were pain score, duration of analgesia, complications, and number of analgesic requirements. The meta-analysis was performed using random-effects models. Results: Fifteen randomized controlled trials (RCTs) were included. There were no differences between clonidine and the control drug regarding the duration of analgesia (SMD = -0.71, 95%CI: -1.64, 0.23; I ² = 95.5%, P_{heterogeneity} < 0.001), pain score (SMD = 0.35, 95%CI: -0.28, 0.98; I ² = 80.8%, P_{heterogeneity} < 0.001), and requirement for additional analgesia (OR = 8.77, 95%CI: 0.70, 110.58, I ² = 81.9%, P_{heterogeneity} = 0.004), but using clonidine resulted in fewer complications than the control drugs (OR = 0.33, 95%CI: 0.20, 0.54, I ² = 21.8%, P_{heterogeneity} = 0.217). The sensitivity analysis showed that the results were robust. A publication bias was observed. Conclusion: Clonidine has the same efficacy as the other adjuvants for caudal epidural block for pediatric surgery but fewer complications. These results support clonidine as an adjuvant to local anesthetic, but additional studies should be conducted.

The effective interplay of (non-) selective NSAIDs with neostigmine in animal models of analgesia and inflammation

BACKGROUND

Surgical procedures cause perioperative immunosuppression and neuroendocrine stress, exerted by activation of the autonomic nervous system and the hypothalamic-pituitary-adrenal axis. The acetylcholinesterase inhibitor (ACHEI); neostigmine, is known clinically for its analgesic effect in the perioperative phases proving high efficacy; besides possessing anti-inflammatory properties controlling immune cells and cytokine level. Hence, this study evaluated and compared the analgesic and anti-inflammatory activities of the combination of selective Cox-2 inhibitor; celecoxib, with neostigmine versus a combination of the non-selective Cox inhibitor; diclofenac, with neostigmine; in different experimental models of analgesia and inflammation in rats.

METHODS

Analgesic activity of neostigmine with/without diclofenac or celecoxib was assessed in female Sprague-Dawely rats using the tail clip model and acetic acid induced writhing. Serum level of β-endorphin was assessed after the tail clip test. The anti-inflammatory activity was evaluated using acute and sub-chronic formalin induced paw edema. At the end of the sub-chronic formalin test, blood samples were collected for analysis of anti-inflammatory, liver and kidney function markers. Livers, kidneys and hind paws were also examined histopathologically.

RESULTS

Addition of neostigmine to selective or non-selective NSAIDs (celecoxib or diclofenac) causes an increased level of analgesia of NSAIDs with rapid onset of action and short duration, while causing potentiation of the anti-inflammatory effect of neostigmine as seen in the tail clip, writhing, formalin test, Cox-1 and Cox-2 activities, serum β-endorphin, TNF-α, NF-кB and HS-CRP. All combinations of this study disturb some kidney and liver functions, however with normal histopathological appearances, while hind paws reveal improved inflammatory infiltration in all treated groups.

CONCLUSIONS

Selective and non-selective NSAIDs examined in this study could be good adjunct options to general anesthetic agents and neostigmine in perioperative stages, an outcome that needs further clinical investigations.

A Prospective Double-Blind Comparative Clinical Study Between Caudal Levobupivacaine (0.125%) with Clonidine and Ropivacaine (0.125%) with Clonidine on Post-Operative Analgesia in Paediatric Patients Undergoing Infra-Umbilical Surgery

Introduction

Caudal epidural block is a reliable technique in paediatric patients but associated with various complications especially with higher concentration of drugs. We proposed a comparative study between levobupivacaine and ropivacaine at low concentration (0.125%) with clonidine at low dose (1 mcg/kg) taken as adjuvant. We aimed to see duration of post-operative analgesia, degree of motor blockade and other associated complications.

Materials and Methods

Eighty paediatric patients (1-6 years), American society of anaesthesiologists grade I and II, undergoing infra-umbilical surgery under general anaesthesia were randomly allocated into two groups of 40 each. Group A patients were given caudal levobupivacaine (0.125%) and Group B patients were given caudal ropivacaine (0.125%). Clonidine (1 mcg/kg) was taken as adjuvant in both the groups. Post-operative pain, sedation and motor blockade were assessed at 30 minutes, 1 hour, 2 hours, 4 hours, 6 hours, 12 hours, 18 hours and 24 hours using Observational Pain Scale, modified Bromage Scale and four-point sedation score, respectively. Any other complications were also noted.

Results

Motor blockade was not associated with any of the patients. Duration of post-operative sedation was similar in both the groups. Duration of post-operative analgesia was significantly higher in Group A (p < 0.0001). Adverse effects and complications were negligible in both the groups.

Conclusion

Both levobupivacaine and ropivacaine can be used safely at low concentration (0.125%) taking clonidine at low dose (1 mcg/kg) as adjuvant in paediatric caudal epidural block without significant motor blockade and other complications, duration of post-operative analgesia being significantly higher in the levobupivacaine group.

A Comparative Clinical Study between Clonidine and Tramadol with Bupivacaine in Caudal Epidural for Postoperative Analgesia in Pediatric Surgery

Context

Adjuvants to bupivacaine for single shot caudal block in children.

Aims

This study entitled was conducted to compare the effects of addition of tramadol to bupivacaine over addition of clonidine to bupivacaine as a single shot caudal block in children.

Settings and Design

Sixty children of ASA grade I and II in the age group of 2-12 years coming for various infra-umbilical surgeries were included.

Materials and Methods

They were divided into two groups of 30 each. Group BC received caudal bupivacaine 0.25% 0.5ml/kg with clonidine 2 mcg/kg Group BT received caudal bupivacaine 0.25% 0.5 ml/kg with tramadol 2 mg/kg. The main parameters studied were hemodynamic changes, duration of post-operative analgesia and incidence of adverse effects.

Statistical Analysis Used

The results of continuous variables are given as mean ± SD and proportion as percentage. The difference between the two groups was assessed by student's - t test and chi-square test.

Results

The mean duration of post-operative analgesia in group BT was statistically significant (P <0.001), reducing the requirement of analgesics in group BT. There was no difference in sedation score, nausea, vomiting, urinary retention.

Conclusions

The present study demonstrated that caudal administration of bupivacaine 0.25% 0.5 ml/kg with tramadol 2 mg/kg resulted in superior analgesia with longer duration of action and reduced requirement of analgesics in first 24 hours postoperatively when compared with 0.25% bupivacaine 0.5 ml/kg with clonidine 2 mcg/kg.

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)

WITHDRAWN: Drugs for preventing postoperative nausea and vomiting

BACKGROUND

Drugs can prevent postoperative nausea and vomiting, but their relative efficacies and side effects have not been compared within one systematic review.

OBJECTIVES

The objective of this review was to assess the prevention of postoperative nausea and vomiting by drugs and the development of any side effects.

SEARCH METHODS

We searched The Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library, Issue 2, 2004), MEDLINE (January 1966 to May 2004), EMBASE (January 1985 to May 2004), CINAHL (1982 to May 2004), AMED (1985 to May 2004), SIGLE (to May 2004), ISI WOS (to May 2004), LILAC (to May 2004) and INGENTA bibliographies.

SELECTION CRITERIA

We included randomized controlled trials that compared a drug with placebo or another drug, or compared doses or timing of administration, that reported postoperative nausea or vomiting as an outcome.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed trial quality and extracted outcome data.

MAIN RESULTS

We included 737 studies involving 103,237 people. Compared to placebo, eight drugs prevented postoperative nausea and vomiting: droperidol, metoclopramide, ondansetron, tropisetron, dolasetron, dexamethasone, cyclizine and granisetron. Publication bias makes evidence for differences among these drugs unreliable. The relative risks (RR) versus placebo varied between 0.60 and 0.80, depending upon the drug and outcome. Evidence for side effects was sparse: droperidol was sedative (RR 1.32) and headache was more common after ondansetron (RR 1.16).

AUTHORS' CONCLUSIONS

Either nausea or vomiting is reported to affect, at most, 80 out of 100 people after surgery. If all 100 of these people are given one of the listed drugs, about 28 would benefit and 72 would not. Nausea and vomiting are usually less common and, therefore, drugs are less useful. For 100 people, of whom 30 would vomit or feel sick after surgery if given placebo, 10 people would benefit from a drug and 90 would not. Between one to five patients out of every 100 people may experience a mild side effect, such as sedation or headache, when given an antiemetic drug. Collaborative research should focus on determining whether antiemetic drugs cause more severe, probably rare, side effects. Further comparison of the antiemetic effect of one drug versus another is not a research priority.

A comparative study of the effect of caudal dexmedetomidine versus morphine added to bupivacaine in pediatric infra-umbilical surgery

BACKGROUND

One of the most commonly used regional anesthetic techniques in pediatric surgeries is the caudal epidural block. Its main disadvantage remains the short duration of action. Hence, different additives have been used. Dexmedetomidine is a potent as well as highly selective α2 adrenergic receptor agonist. The aim of this randomized, double-blinded, study was to compare the duration of postoperative analgesia of caudal dexmedetomidine versus morphine in combination with bupivacaine in pediatric patients undergoing lower abdominal or perineal surgery.

PATIENTS AND METHODS

A total of 50 pediatric patients 1-5 years old The American Society of Anesthesiologists status I, II scheduled for lower abdominal and perineal surgeries were included in the study. The patients were enrolled into 2 equal groups: Group A patients (n = 25) received dexmedetomidine with bupivacaine while Group B patients (n = 25) received morphine with bupivacaine. Patients were placed in a supine position then inhalational general anesthesia was induced, and laryngeal mask airway (LMA) was placed. Patients were then given caudal epidural analgesia. By the end of surgery reversal of muscle relaxation was done and the LMA was removed. Post-operatively, the sedation as well as pain score were observed and recorded.

RESULTS

The current study showed that minor complications were recorded in the post-anesthesia care unit; in addition, significantly longer periods of analgesia and sedation were detected in Group A. However, no significant differences in demographic data, as well as in the duration of surgery, and the time of emergence from anesthesia and patient condition during recovery were detected.

CONCLUSION

The present study suggested that use of dexmedetomidine, during single dose injection, as an additive to the local anesthetic bupivacaine in caudal epidural analgesia prolongs the duration of post-operative analgesia following lower abdominal as well as perineal surgery compared with caudal morphine with no side-effects on the vital signs. Postoperative side effects were seen with caudal morphine injection rather than with dexmedetomidine.

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.

Longer than expected-duration of caudal analgesia with two different doses of levobupivacaine in children undergoing hypospadias repair

OBJECTIVE

To assess our study design and to obtain preliminary data for a dose-effect study on levobupivacaine for caudal analgesia in patients undergoing hypospadias repair.

STUDY DESIGN

non randomised, non-blinded pilot study.

METHOD

For this non-randomized, non-blinded pilot study, 20 patients (median age 17 months, median weight 10.5 kg) were allocated to two groups receiving either 0.5 mL kg(-1) levobupivacaine 0.125% (Group 0) or 0.5 mL kg(-1) levobupivacaine 0.375% (Group 1) caudally after induction of anaesthesia for pain control. No further analgesia was given before, during or after the procedure. Pain scores (Children's and Infants' Postoperative Pain Scale) were recorded throughout the observation period, which lasted from the start of the procedure until hospital discharge on the following day.

RESULTS

Group 0: six out of 10 patients remained pain free throughout the observation period. Group 1: six out of seven patients remained pain free throughout the observation period.

CONCLUSION

Both concentrations of levobupivacaine provided excellent analgesia throughout surgery. The postoperative analgesia with both doses of levobupivacaine was found to be significantly longer lasting than previously reported. The study design, with a tight and extensive observation scheme, proved to be feasible, but given the surprisingly long-lasting analgesia, the observation period needs to be extended in future studies.

Intravenous regional anesthesia using lidocaine and neostigmine for upper limb surgery

STUDY OBJECTIVE

To evaluate the effect of adding neostigmine to lidocaine in intravenous regional anesthesia (IVRA).

DESIGN

Randomized, double-blinded study.

SETTING

Tertiary-care academic medical institution.

PATIENTS

40 ASA physical status I and II patients scheduled for elective or emergency forearm and hand surgery.

INTERVENTION

Patients were randomized to two groups of 20 patients each. In the control group, IVRA was established using 40 mL of 0.5% lidocaine with one mL of isotonic saline, while neostigmine group patients received 40 mL of 0.5% lidocaine with 0.5 mg neostigmine.

MEASUREMENTS

Hemodynamic parameters, onset and recovery times of sensory and motor blocks, and quality of anesthesia achieved with IVRA were recorded. After tourniquet deflation, visual analog pain scores (VAS) were noted every 30 minutes in the first two hours, as were the time to first analgesic request and total analgesic requirement in the 24-hour postoperative period.

MAIN RESULTS

In the first 24 hours after surgery, the neostigmine group had significantly lower VAS scores, longer time to first analgesic request, and reduced total analgesic requirement. Intraoperatively, the neostigmine group had significantly shorter sensory and motor block onset times and longer recovery times than the control group. No significant frequency of adverse effects was seen in either group. The quality of intraoperative anesthesia and frequency of tourniquet pain were similar in both groups.

CONCLUSIONS

The addition of neostigmine to lidocaine shortens onset time and improves postoperative analgesia in IVRA for upper limb surgery.

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 x kg(-1)) with neostigmine (2 microg x kg(-1)) (group BN) or tramadol (1 mg x 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 x kg(-1)) compared with neostigmine (2 microg x kg(-1)) might provide both prolonged duration of analgesia and extended time to first analgesic in caudal block.

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

SUMMARY 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 genitourinary 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 microg.kg(-1) respectively) together with levobupivacaine used in the same does as Group I. Pain scores were assessed using Children's and Infant's Postoperative Pain Scale (CHIPPS) at 15th (t(1)) min after arrival to postanesthetic care unit, and 1st (t(2)), 2nd (t(3)), 3rd (t(4)), 4th (t(5)), 8th (t(6)), 16th (t(7)), and 24th (t(8)) 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 t(2), t(3), t(6), t(7), and t(8) 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 microg.kg(-1) with levobupivacaine extends the duration of analgesia without increasing the incidence of adverse effects, and 2 microg.kg(-1) seems to be the optimal dose, as higher dose has no further advantages.

Comparison of caudal epidural bupivacaine with bupivacaine plus tramadol and bupivacaine plus ketamine for postoperative analgesia in children

This study compared the effect of single-dose caudal epidural bupivacaine, bupivacaine plus ketamine and bupivacaine plus tramadol for postoperative pain management in children having surgery for inguinal hernia. Following ethics committee approval and informed parental consent, 75 children ASA PS I and II, between three and nine years of age and scheduled for elective unilateral inguinal hernia repair with general anaesthesia were recruited. The patients were randomly divided into three groups to receive 0.5 ml/kg caudal bupivacaine 0.25% (group B), bupivacaine 0.25% plus tramadol 1 mg/kg (group BT) or bupivacaine 0.25% plus ketamine 0.5 mg/kg (group BK). The injections were performed under general anaesthesia. Mean arterial pressure, heart rate, pulse oximetry, respiratory rate and sedation and pain scores were recorded at defined intervals following recovery from anaesthesia. The groups were similar in age, weight and duration of operation (P >0.05). No patient experienced hypotension, bradycardia or respiratory depression. Duration of analgesia was (mean+/-SD) 6.5+/-4.1 h in group B, 9.2+/-3.9 h in group BK, and 8.5+/-3.1 h in group BT (P <0.05). More patients in group B required supplementary analgesics in the first 24 h (P <0.05). Sedation scores were comparable in all groups. Incidence of emesis and pruritus was similar in all the groups. Caudally administered 0.5 ml/kg bupivacaine 0.25% plus ketamine or bupivacaine 0.25% plus tramadol 1 mg/kg provided significantly longer duration of analgesia without an increase in the adverse effects when compared to bupivacaine alone.

Use of neostigmine in the management of acute postoperative pain and labour pain: a review

Neostigmine is a parasympathomimetic agent that has been recently investigated for use as an adjunct analgesic agent in the perioperative and peripartum period. A number of studies have investigated the intrathecal, epidural, caudal and intra-articular routes of administration of this agent, as well as the addition of neostigmine to local anaesthetics used for brachial plexus block and intravenous regional anaesthesia. While the intrathecal administration of neostigmine produced useful analgesic effects in the postoperative period in some studies, the high incidence of adverse events, mainly nausea and vomiting, limit the clinical usefulness of this route of administration. Several studies investigated the postoperative analgesic effects of epidural neostigmine using a number of different regimens. Overall, this route of administration appeared to improve postoperative analgesia in most studies without increasing the incidence of adverse events, and merits further research. Neuraxial administration of neostigmine appears to be safe in the obstetric population, with no reported adverse effects in the mother or fetus. While intrathecal administration is limited by a high incidence of nausea and vomiting in this patient population, the epidural route appears more promising and requires further investigation. The addition of neostigmine to caudal local anaesthetics was associated with improved postoperative analgesia in a number of studies. A dose of 2 microg/kg proved to be effective in several studies but was associated with an increased incidence of vomiting in some studies. Intra-articular administration of neostigmine 500microg produced a useful analgesic effect in the postoperative period in several studies and was not associated with an increase in the incidence of adverse effects. Studies investigating the efficacy of adding neostigmine to the local anaesthetics used for brachial plexus block and intravenous regional anaesthesia reported conflicting results. Further studies are required to determine the place of the administration of neostigmine by these routes.

Drugs for preventing postoperative nausea and vomiting

BACKGROUND

Drugs can prevent postoperative nausea and vomiting, but their relative efficacies and side effects have not been compared within one systematic review.

OBJECTIVES

The objective of this review was to assess the prevention of postoperative nausea and vomiting by drugs and the development of any side effects.

SEARCH STRATEGY

We searched The Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library, Issue 2, 2004), MEDLINE (January 1966 to May 2004), EMBASE (January 1985 to May 2004), CINAHL (1982 to May 2004), AMED (1985 to May 2004), SIGLE (to May 2004), ISI WOS (to May 2004), LILAC (to May 2004) and INGENTA bibliographies.

SELECTION CRITERIA

We included randomized controlled trials that compared a drug with placebo or another drug, or compared doses or timing of administration, that reported postoperative nausea or vomiting as an outcome.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed trial quality and extracted outcome data.

MAIN RESULTS

We included 737 studies involving 103,237 people. Compared to placebo, eight drugs prevented postoperative nausea and vomiting: droperidol, metoclopramide, ondansetron, tropisetron, dolasetron, dexamethasone, cyclizine and granisetron. Publication bias makes evidence for differences among these drugs unreliable. The relative risks (RR) versus placebo varied between 0.60 and 0.80, depending upon the drug and outcome. Evidence for side effects was sparse: droperidol was sedative (RR 1.32) and headache was more common after ondansetron (RR 1.16).

AUTHORS' CONCLUSIONS

Either nausea or vomiting is reported to affect, at most, 80 out of 100 people after surgery. If all 100 of these people are given one of the listed drugs, about 28 would benefit and 72 would not. Nausea and vomiting are usually less common and, therefore, drugs are less useful. For 100 people, of whom 30 would vomit or feel sick after surgery if given placebo, 10 people would benefit from a drug and 90 would not. Between one to five patients out of every 100 people may experience a mild side effect, such as sedation or headache, when given an antiemetic drug. Collaborative research should focus on determining whether antiemetic drugs cause more severe, probably rare, side effects. Further comparison of the antiemetic effect of one drug versus another is not a research priority.

Some current controversies in paediatric regional anaesthesia

PURPOSE OF REVIEW

Controversial topics in paediatric regional anaesthesia are discussed.

RECENT FINDINGS

The performance of blocks under general anaesthesia, new local anaesthetics, adjuvants, location techniques, and risks of masking compartment syndromes are contemplated.

SUMMARY

The performance of regional blocks in anaesthetized patients is generally contra-indicated in adults but accepted in children. Levobupivacaine displays the same pharmacokinetic profile as racemic bupivacaine with possibly less cardiac toxicity. Ropivacaine undergoes slower absorption and, in some studies, concomitant increase in peak plasma concentration in infants. Conversely, continuous infusion of ropivacaine offers the safest therapeutic index. Many adjuvants have been used but only epinephrine, clonidine, and preservative-free ketamine offer clear advantages. Midazolam and neostigmine are effective but have potential drawbacks and raise safety questions. Needle and catheter positioning is critical. Electrocardiogram guidance and electrical stimulation occasionally help identify the migration of epidural catheters. Stimulating catheters might be useful for continuous peripheral blockade. Ultrasonography will probably become the reference technique for peripheral catheter placement. Patients at risk of compartment syndrome must be monitored (measurement of compartmental pressures); adequate pain management does not 'hide' this complication but, on the contrary, can facilitate early diagnosis since the increase in requirement for pain medication precedes other clinical symptoms by an average of 7.3 h.

The changing role of non-opioid analgesic techniques in the management of postoperative pain

Given the expanding role of ambulatory surgery and the need to facilitate an earlier hospital discharge, improving postoperative pain control has become an increasingly important issue for all anesthesiologists. As a result of the shift from inpatient to outpatient surgery, the use of IV patient-controlled analgesia and continuous epidural infusions has steadily declined. To manage the pain associated with increasingly complex surgical procedures on an ambulatory or short-stay basis, anesthesiologists and surgeons should prescribe multimodal analgesic regimens that use non-opioid analgesics (e.g., local anesthetics, nonsteroidal antiinflammatory drugs, cyclooxygenase inhibitors, acetaminophen, ketamine, alpha 2-agonists) to supplement opioid analgesics. The opioid-sparing effects of these compounds may lead to reduced nausea, vomiting, constipation, urinary retention, respiratory depression and sedation. Therefore, use of non-opioid analgesic techniques can lead to an improved quality of recovery for surgical patients.

Caudal Additives in Pediatrics: A Comparison Among Midazolam, Ketamine, and Neostigmine Coadministered with Bupivacaine

Single-shot "kiddie caudal" with bupivacaine alone is losing popularity because of its duration of 4-8 h. In a prospective randomized double-blind clinical study, we assessed and compared the efficacy of ketamine, midazolam, and neostigmine coadministered with bupivacaine in a caudal epidural to provide intraoperative and postoperative pain relief. Eighty children (ASA status I) aged 5-10 yr undergoing unilateral inguinal herniotomy were allocated randomly in equal numbers (n = 20) into 4 groups to receive a caudal injection of 0.25% bupivacaine (1 mL/kg) with or without ketamine (0.5 mg/kg), midazolam (50 microg/kg), and neostig-mine (2 microg/kg), after the induction of standardized general anesthesia without premedication. Monitoring for pain, sedation, postoperative nausea/vomiting, dizziness, and pruritus was performed by anesthesiologists blinded to the study allocation. The time to first analgesic administration (paracetamol syrup) was longer (P < 0.05) in the bupivacaine-neostigmine group and the bupivacaine-midazolam group than in the other groups. Undesirable effects, such as emesis, pruritus, and dizziness, were comparable in all groups. However, the incidence of hallucination was more frequent in the bupivacaine-ketamine group compared with the other groups. This study shows that single-shot caudal coadministration of bupivacaine-neostigmine and bupivacaine-midazolam was associated with an extended duration of postoperative pain relief.

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.

Caudal neostigmine with bupivacaine produces a dose-independent analgesic effect in children

PURPOSE

To evaluate the analgesic efficacy and duration of varying doses of caudal neostigmine with plain bupivacaine and its side effects in children undergoing genito-urinary surgery.

METHODS

In a randomized double-blind prospective study 80 boys aged two to eight years scheduled for surgical repair of hypospadias were allocated randomly to one of four groups (n = 20 each) and received either only caudal 0.25% plain bupivacaine 0.5 mL.kg(-1) (Group I) or 0.25% plain bupivacaine 0.5 mL.kg(-1) with neostigmine (Groups II-IV) in doses of 2, 3 and 4 microg.kg(-1) respectively. Postoperative pain was assessed for 24 hr using an objective pain score. Blood pressure, heart rate, oxygen saturation, total amount of analgesic consumed and adverse effects were also recorded.

RESULTS

The duration of postoperative analgesia in Group I (5.1 +/- 2.3 hr) was significantly shorter than in the other three groups (II -16.6 +/- 4.9 hr; III - 17.2 +/- 5.5 hr; IV - 17.0 +/- 5.8 hr; P < 0.05). Total analgesic (paracetamol) consumption was significantly more in Group I (697.6 +/- 240.7 mg) than in the groups receiving caudal neostigmine (II - 248.0 +/- 178.4; III - 270.2 +/- 180.8 and IV -230.6 +/- 166.9 mg; P < 0.05). Groups II, III and IV were comparable with regards to duration of postoperative analgesia and total analgesic consumption (P > 0.05). Incidence of nausea and vomiting were comparable in all four groups. No significant alteration in vital signs or any other adverse effects were observed.

CONCLUSIONS

Caudal neostigmine (2, 3 and 4 microg.kg(-1)) with bupivacaine produces a dose-independent analgesic effect ( approximately 16-17 hr) in children as compared to those receiving caudal bupivacaine alone (approximately five hours) and a reduction in postoperative rescue analgesic consumption without increasing the incidence of adverse effects.

Caudal additives for postoperative pain management in children: S(+)-ketamine and neostigmine

BACKGROUND

The aim of the present pilot study was to compare the analgesic efficacy of S(+)-ketamine either alone or in combination with neostigmine for caudal blockade in pediatric surgery.

METHODS

A total of 40 children were randomly assigned to receive after induction of general anesthesia either caudal S(+)-ketamine 1 mg.kg(-1) (group K, n = 20) or caudal S (+)-ketamine 0.5 mg.kg(-1) plus neostigmine 10 microg.kg(-1) (group KN, n = 20). Anesthesia was maintained with sevoflurane and a laryngeal mask airway (LMA), no additional analgesics were administered. Postoperative pain and sedation were assessed by the Children's Hospital of Eastern Ontario Pain Score and Ramsay scale for 24 h.

RESULTS

No statistical difference in duration of analgesia and sedation was found. Mean duration of postoperative analgesia was 18 +/- 9.4 h in group K and 21.8 +/- 6.7 h in group KN. There was a significantly higher incidence of postoperative vomiting after administration of caudal ketamine with neostigmine (30% group KN Vs 0% group K; P < 0.05).

CONCLUSIONS

This pilot study demonstrates equianalgesic effects on postoperative pain relief in children with both caudal S(+)-ketamine 1 mg.kg(-1) and caudal S(+)-ketamine 0.5 mg.kg(-1) plus neostigmine 10 microg.kg(-1). Further studies are required to confirm adoption of caudal neostigmine into routine clinical practice.

Postoperative neuraxial pain relief in the pediatric patient

Pain serves as a useful warning function of potential tissue damage. The systemic response to pain is characterized by activation of the sympathetic nervous system. The ensuing neuroendocrine response results in a myriad of adverse effects on the various organ systems, which can adversely affect surgical outcomes. When effective neuraxial anesthesia and analgesic techniques are employed, the surgical patient may benefit from decreases in morbidity, mortality, and prevention of subsequent development of chronic pain. The use of intrathecal and epidural techniques in the pediatric population is well established and allows these patients to benefit from superior pain relief and improved surgical outcomes.

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.

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.