Efficacy of low-dose caudal clonidine in reduction of sevoflurane-induced agitation in children undergoing urogenital and lower limb surgery: a prospective randomised double-blind study:

Association of pharmacological prophylaxis with the risk of pediatric emergence delirium after sevoflurane anesthesia: An updated network meta-analysis

STUDY OBJECTIVE

This updated network meta-analysis aims at exploring whether the concurrent use of midazolam or antiemetics may enhance the efficacy of other pharmacological regimens for delirium prophylaxis in pediatric population after general anesthesia (GA).

DESIGN

Network meta-analysis (PROSPERO registration: CRD42020179483).

SETTING

Postoperative recovery area.

PATIENTS

Pediatric patients undergoing GA with sevoflurane.

INTERVENTIONS

Pharmacological interventions applied during GA with sevoflurane.

MEASUREMENTS

This network meta-analysis of randomized controlled trials (RCTs) was conducted with a frequentist model. PubMed, Embase, ProQuest, ScienceDirect, Cochrane CENTRAL, ClinicalKey, Web of Science, and ClinicalTrials.gov were searched from their inception dates to April 12, 2020, for RCTs of either placebo-controlled or active-controlled design containing information on the incidence of emergence delirium in pediatric patients undergoing sevoflurane anesthesia.

MAIN RESULTS

Seventy studies comprising 6904 participants were included for the analysis of 30 pharmacological interventions. Based on surface under the cumulative ranking curve (SUCRA) analysis, midazolam was ranked the lowest in therapeutic effect (SUCRA: 20%), while antiemetics as a monotherapy had no effect on delirium prophylaxis. However, there was a trend that most combination therapies with midazolam or antiemetics were superior to monotherapies for delirium prophylaxis. Subgroup analyses based on age (i.e., ≤7 years) and a validated scoring system (i.e., the Pediatric Anesthesia Emergence Delirium scale) for delirium also suggested a better efficacy of combination therapies than monotherapies. Overall, combination therapies with midazolam or antiemetics did not have a negative impact on the incidence of postoperative nausea and vomiting, length of stay in the postanesthesia care unit, or time to extubation. The dexmedetomidine-midazolam-antiemetic combination was the most effective strategy for the prevention of emergence delirium.

CONCLUSIONS

This network meta-analysis suggested that the incorporation of midazolam or antiemetics as adjuncts for combination therapies may have synergistic effects against pediatric postoperative emergence delirium. Future large-scale placebo-controlled RCTs are warranted to validate our findings.

Optimal Dexmedetomidine Dose to Prevent Emergence Agitation Under Sevoflurane and Remifentanil Anesthesia During Pediatric Tonsillectomy and Adenoidectomy

Background: Emergence agitation (EA) is a common pediatric complication after sevoflurane anesthesia that can be prevented with dexmedetomidine. However, an inappropriate dose of dexmedetomidine can cause prolonged sedation and cardiovascular complications. Thus, we evaluated the optimal dose (ED95) of dexmedetomidine for preventing EA with sevoflurane and remifentanil anesthesia after pediatric tonsillectomy and adenoidectomy.

Methods: We enrolled American Society of Anesthesiologists (ASA) I and II children 3–7 years of age who underwent tonsillectomy with adenoidectomy. During induction, dexmedetomidine was infused for 10 min. Anesthesia was induced with sevoflurane and maintained with sevoflurane and remifentanil, resulting in a bispectral spectrum index (BIS) range from 40 to 60. Extubation time, surgical and anesthetic duration time, and duration time in the postanesthesia care unit (PACU) stay were recorded. EA [measured with Pediatric Anaesthesia Emergence Delirium (PAED) scores] and pain [measured with Face, Legs, Activity, Cry, Consolability (FLACC) scores] were assessed at extubation (E0), 15 min after extubation (E1), and 30 min after extubation (E2). If EA occurred, the next surgical procedure included increased dexmedetomidine by 0.1 μg/kg, and if not, the drug was reduced by 0.1 μg/kg.

Results: The 50% effective dose (ED50) of dexmedetomidine for preventing EA after sevoflurane and remifentanil anesthesia for tonsillectomy and adenoidectomy was 0.13 μg/kg, and its 95% confidence interval is 0.09–0.19 μg/kg; ED95 was 0.30 μg/kg, and its 95% confidence interval is 0.21–1.00 μg/kg.

Conclusion: Intravenous dexmedetomidine infusion at ED50 (0.13 μg/kg) or ED95 (0.30 μg/kg) during induction for 10 min can prevent half or almost all EA after sevoflurane and remifentanil anesthesia during pediatric tonsillectomy and adenoidectomy.

Clonidine in pediatric anesthesia: the new panacea or a drug still looking for an indication?

PURPOSE OF REVIEW

Clonidine, an α2-receptor agonist is a widely used drug in pediatrics with a large scope of indications ranging from prevention of postoperative emergence agitation, analgesia, anxiolysis, sedation, weaning to shivering. In the era of 'opioid-free' medicine with much attention be directed toward increasing problems with opioid use, clonidine due to its global availability, low cost and safety profile has become an even more interesting option.

RECENT FINDINGS

Increasing evidence from randomised clinical trials support the use of clonidine in healthy children in the perioperative setting. Clonidine appears to significantly reduce postoperative emergence agitation, opioid consumption, shivering, nausea and vomiting. In addition, emerging evidence support the use of clonidine for sedation of critically ill children in ICUs. In this review, the current evidence for clonidine in pediatrics is described and analyzed including a meta-analysis for prevention of emergence agitation.

SUMMARY

Clonidine appears a safe and beneficial drug with moderate to high-quality evidence supporting its use in pediatric anesthesia. However, for some indications and populations such as children younger than 12 months old and those with hemodynamic instability, there is an urgent need for high-quality trials.

Emergence Delirium in Pediatric Anesthesia

Emergence delirium (ED) is a complex of perceptual disturbances and psychomotor agitation that occurs most commonly in preschool-aged children in the early postanesthetic period. The incidence of ED varies between 10 and 80% in children and is perceived as a troublesome clinical situation by 42% of pediatric anesthesiologists. Although these events are often short lived, they increase the risk of self-injury and delayed discharge, require additional nursing staff and can increase medical care costs, all of which are causes for concern. The prevalence of ED has increased with the introduction and growing use of sevoflurane and desflurane, two low-solubility inhalational anesthetics. These agents promote early arousal post anesthetic, which contributes to ED. Physiological factors, pharmacological factors, the type of procedure, the anesthetic agent administered, painful stimuli, and various patient factors can all contribute to ED and thus need to be considered. Recent literature debates the cause-effect relationship between ED and pain, suggesting that they often occur concurrently but are sometimes independent findings. The consistent relation between ED and sevoflurane-based anesthesia has guided many studies to investigate its incidence compared with using other anesthetic techniques or various adjuncts. The risk of ED is lowest when propofol is used as a single-agent anesthetic compared with sevoflurane-based anesthetics. Adjunctive agents can be rated in the following order of most effective to least effective interventions: dexmedetomidine, fentanyl, ketamine, clonidine, and propofol bolus at the end of sevoflurane-based anesthesia. This review summarizes the factors that may predict ED and provides an intervention algorithm to guide effective prevention and treatment.

Efficacy and Acceptability of Different Auxiliary Drugs in Pediatric Sevoflurane Anesthesia: A Network Meta-analysis of Mixed Treatment Comparisons

Emergence agitation preventive medicine should be combined with pediatric anesthesia because of the high frequency of emergence agitation. However, it is challenging to determine the most appropriate medication that can be introduced into pediatric anesthesia for the sake of emergence agitation prevention. We reviewed and retrieved the data from PubMed and Embase. Various medications were assessed based on several endpoints including Emergence agitation outcomes (EA), postoperative nausea and vomiting (PONV), the number of patients who required analgesic (RA), pediatric anesthesia emergence delirium (PAED), the extubation time, the emergency time and the duration of post-anesthesia care unit (PACU) stay. Both traditional and network meta-analysis were carried in this study. A total of 45 articles were complied with the selection criteria and the corresponding articles were reviewed. Fentanyl demonstrated the highest cumulative ranking probability which was followed by those of ketamine and dexmedetomidine with respect to EA and PAED. When PONV and RA were concerned together, clonidine exhibited the highest cumulative ranking probability compared to other medications. Our study suggested that dexmedetomidine perhaps is the most appropriate prophylactic treatment which can be introduced into anesthesia for preventing emergence agitation.

μ-Opioid agonists for preventing emergence agitation under sevoflurane anesthesia in children: a meta-analysis of randomized controlled trials

BACKGROUND

Emergence agitation (EA) is an adverse effect after sevoflurane anesthesia in pediatric patients. The effectiveness of prophylactic μ-opioid agonists fentanyl, remifentanil, sufentanil, and alfentanil in preventing EA is debatable.

METHODS

A literature search was conducted to identify clinical trials that observed the effect of μ-opioid agonists fentanyl, remifentanil, sufentanil, and alfentanil on preventing EA in pediatric patients under sevoflurane anesthesia. The statistical software RevMan 5.3 was used for meta-analysis. Data from each study were combined using the relative ratio (RR), weighted mean differences, and their associated 95% confidence intervals. I(2) was used to evaluate heterogeneity. Subgroup analysis was conducted to investigate the possible influences of patient age, adenotonsillectomy, premedication, N2 O, propofol, and regional block/local anesthetics on preventing EA with prophylactic administration of μ-opioid agonists. Publication bias was checked using funnel plots and Begg's test.

RESULTS

This meta-analysis showed the inclusion of 19 randomized controlled trials with 1528 patients (857 patients received μ-opioid agonists therapy and 671 patients had placebo). The pooled data indicated that prophylactic μ-opioid agonists fentanyl, remifentanil, sufentanil, and alfentanil significantly decreased the incidence of EA [RR = 0.49 (0.38, 0.64), I(2) = 42%, P = 0.04; RR = 0.57 (0.33, 0.99), I(2) = 37%, P = 0.19; RR = 0.18 (0.08, 0.39), I(2) = 0%, P = 0.98; and RR = 0.56 (0.40, 0.78), I(2) = 6%, P = 0.34, respectively]. All subgroup analyses strengthened the proof for lower incidence of EA under sevoflurane anesthesia after fentanyl administration. A possibility of publication bias was detected in the fentanyl group.

CONCLUSIONS

This meta-analysis suggested that prophylactic μ-opioid agonists fentanyl, remifentanil, sufentanil, and alfentanil could significantly decrease the incidence of EA under sevoflurane anesthesia in children compared to placebo. Considering the limitations of the included studies, more clinical studies are required.

Barbiturate Induction for the Prevention of Emergence Agitation after Pediatric Sevoflurane Anesthesia

OBJECTIVES

Emergence agitation (EA) is a common and troublesome problem in pediatric patients recovering from general anesthesia. The incidence of EA is reportedly higher after general anesthesia maintained with sevoflurane, a popular inhalational anesthetic agent for pediatric patients. We conducted this prospective, randomized, double-blind study to test the effect of an intravenous ultra-short-acting barbiturate, thiamylal, administered during induction of general anesthesia on the incidence and severity of EA in pediatric patients recovering from Sevoflurane anesthesia.

METHODS

Fifty-four pediatric patients (1 to 6 years of age) undergoing subumbilical surgeries were randomized into 2 groups. Patients received either intravenous thiamylal 5mg/kg (Group T) or inhalational Sevoflurane 5% (Group S) as an anesthetic induction agent. Following induction, general anesthesia was maintained with Sevoflurane and nitrous oxide (N2O) in both groups. To control the intra- and post-operative pain, caudal block or ilioinguinal/iliohypogastric block was performed. The incidence and severity of EA were evaluated by using the Modified Objective Pain Scale (MOPS: 0 to 6) at 15 and 30 min after arrival in the post-anesthesia care unit (PACU).

RESULTS

Fifteen minutes after arrival in the PACU, the incidence of EA in Group T (28%) was significantly lower than in Group S (64%; p = 0.023) and the MOPS in Group T (median 0, range 0 to 6) was significantly lower than in Group S (median 4, range 0 to 6; p = 0.005). The interval from discontinuation of Sevoflurane to emergence from anesthesia was not significantly different between the 2 groups.

CONCLUSIONS

Thiamylal induction reduced the incidence and severity of EA in pediatric patients immediately after Sevoflurane anesthesia.

Effect of caudal clonidine on emergence agitation and postoperative analgesia after sevoflurane anaesthesia in children: Randomised comparison of two doses

BACKGROUND AND AIMS

Sevoflurane, a popular inhalational anaesthetic for children, has been associated with significant emergence agitation in the recovery phase. This study was intended to compare two doses of caudal clonidine added to ropivacaine 0.2% in order to decide on the optimal dose for prevention of sevoflurane induced emergence agitation (EA) and to get a meaningful prolongation of postoperative analgesia with minimal side effects.

METHODS

Sixty-one children aged 1-7 years (American Society of Anaesthesiologists physical status I-II) received standardized general anaesthesia with inhaled sevoflurane and caudal epidural block with 0.2% ropivacaine 1 ml/kg for sub-umbilical surgeries. They were assigned randomly to two groups: (I) clonidine 1 μg/kg added to caudal ropivacaine; (II) clonidine 2 μg/kg added to caudal ropivacaine. EA and postoperative analgesia were assessed using pain/discomfort scale score and face, legs, activity, cry, consolability (FLACC) score respectively.

RESULTS

EA was observed in 8 children (26.6%) in group I when compared to only 2 children (6.4%) in group II after first 15 min postoperatively. Incidences of EA at 15 min, as well as total incidence of agitation, were both significantly lower in group II when compared to group I with P < 0.05. Duration of analgesia in group I (12 [8-20] h) and group II (16 [8-20] h) was statistically comparable (P > 0.05). There was no difference in the incidence of sedation or complications.

CONCLUSION

Caudal clonidine 2 μg/kg added to 0.2% ropivacaine 1 ml/kg is suggested to be the optimal dose, for prevention of EA and meaningful prolongation of postoperative analgesia with minimal side-effects.

Effects of sevoflurane versus other general anaesthesia on emergence agitation in children

BACKGROUND

Sevoflurane is an inhaled volatile anaesthetic that is widely used in paediatric anaesthetic practice. Since its introduction, postoperative behavioural disturbance known as emergence agitation (EA) or emergence delirium (ED) has been recognized as a problem that may occur during recovery from sevoflurane anaesthesia. For the purpose of this systematic review, EA has been used to describe this clinical entity. A child with EA may be restless, may cause self-injury or may disrupt the dressing, surgical site or indwelling devices, leading to the potential for parents to be dissatisfied with their child's anaesthetic. To prevent such outcomes, the child may require pharmacological or physical restraint. Sevoflurane may be a major contributing factor in the development of EA. Therefore, an evidence-based understanding of the risk/benefit profile regarding sevoflurane compared with other general anaesthetic agents and adjuncts would facilitate its rational and optimal use.

OBJECTIVES

To compare sevoflurane with other general anaesthetic (GA) agents, with or without pharmacological or non-pharmacological adjuncts, with regard to risk of EA in children during emergence from anaesthesia. The primary outcome was risk of EA; secondary outcome was agitation score.

SEARCH METHODS

We searched the following databases from the date of inception to 19 January 2013: CENTRAL, Ovid MEDLINE, Ovid EMBASE, the Cumulative Index to Nursing and Allied Health Literature (CINAHL) (EBSCOhost), Evidence-Based Medicine Reviews (EBMR) and the Web of Science, as well as the reference lists of other relevant articles and online trial registers.

SELECTION CRITERIA

We included all randomized (or quasi-randomized) controlled trials investigating children < 18 years of age presenting for general anaesthesia with or without surgical intervention. We included any study in which a sevoflurane anaesthetic was compared with any other GA, and any study in which researchers investigated adjuncts (pharmacological or non-pharmacological) to sevoflurane anaesthesia compared with no adjunct or placebo.

DATA COLLECTION AND ANALYSIS

Two review authors independently searched the databases, decided on inclusion eligibility of publications, ascertained study quality and extracted data. They then resolved differences between their results by discussion. Data were entered into RevMan 5.2 for analyses and presentation. Comparisons of the risk of EA were presented as risk ratios (RRs) with 95% confidence intervals (CIs). Sevoflurane is treated as the control anaesthesia in this review. Sensitivity analyses were performed as appropriate, to exclude studies with a high risk of bias and to investigate heterogeneity.

MAIN RESULTS

We included 158 studies involving 14,045 children. Interventions to prevent EA fell into two broad groups. First, alternative GA compared with sevoflurane anaesthesia (69 studies), and second, use of an adjunct with sevoflurane anaesthesia versus sevoflurane without an adjunct (100 studies). The overall risk of bias in included studies was low. The overall Grades of Recommendation, Assessment, Development and Evaluation Working Group (GRADE) assessment of the quality of the evidence was moderate to high. A wide range of EA scales were used, as were different levels of cutoff, to determine the presence or absence of EA. Some studies involved children receiving potentially inadequate or no analgesia intraoperatively during painful procedures.Halothane (RR 0.51, 95% CI 0.41 to 0.63, 3534 participants, high quality of evidence) and propofol anaesthesia were associated with a lower risk of EA than sevoflurane anaesthesia. Propofol was effective when used throughout anaesthesia (RR 0.35, 95% CI 0.25 to 0.51, 1098 participants, high quality of evidence) and when used only during the maintenance phase of anaesthesia after sevoflurane induction (RR 0.59, 95% CI 0.46 to 0.76, 738 participants, high quality of evidence). No clear evidence was found of an effect on risk of EA of desflurane (RR 1.46, 95% CI 0.92 to 2.31, 408 participants, moderate quality of evidence) or isoflurane (RR 0.76, 95% CI 0.46 to 1.23, 379 participants, moderate quality of evidence) versus sevoflurane.Compared with no adjunct, effective adjuncts for reducing the risk of EA during sevoflurane anaesthesia included dexmedetomidine (RR 0.37, 95% CI 0.29 to 0.47, 851 participants, high quality of evidence), clonidine (RR 0.45, 95% CI 0.31 to 0.66, 739 participants, high quality of evidence), opioids, in particular fentanyl (RR 0.37, 95% CI 0.27 to 0.50, 1247 participants, high quality of evidence) and a bolus of propofol (RR 0.58, 95% CI 0.38 to 0.89, 394 participants, moderate quality of evidence), ketamine (RR 0.30, 95% CI 0.13 to 0.69, 231 participants, moderate quality of evidence) or midazolam (RR 0.57, 95% CI 0.41 to 0.81, 116 participants, moderate quality of evidence) at the end of anaesthesia. Midazolam oral premedication (RR 0.81, 95% CI 0.59 to 1.12, 370 participants, moderate quality of evidence) and parental presence at emergence (RR 0.91, 95% CI 0.51 to 1.60, 180 participants, moderate quality of evidence) did not reduce the risk of EA.One or more factors designated as high risk of bias were noted in less than 10% of the included studies. Sensitivity analyses of these studies showed no clinically relevant changes in the risk of EA. Heterogeneity was significant with respect to these comparisons: halothane; clonidine; fentanyl; midazolam premedication; propofol 1 mg/kg bolus at end; and ketamine 0.25 mg/kg bolus at end of anaesthesia. With investigation of heterogeneity, the only clinically relevant changes to findings were seen in the context of potential pain, namely, the setting of adenoidectomy/adenotonsillectomy (propofol bolus; midazolam premedication) and the absence of a regional block (clonidine).

AUTHORS' CONCLUSIONS

Propofol, halothane, alpha-2 agonists (dexmedetomidine, clonidine), opioids (e.g. fentanyl) and ketamine reduce the risk of EA compared with sevoflurane anaesthesia, whereas no clear evidence shows an effect for desflurane, isoflurane, midazolam premedication and parental presence at emergence. Therefore anaesthetists can consider several effective strategies to reduce the risk of EA in their clinical practice. Future studies should ensure adequate analgesia in the control group, for which pain may be a contributing or confounding factor in the diagnosis of EA. Regardless of the EA scale used, it would be helpful for study authors to report the risk of EA, so that this might be included in future meta-analyses. Researchers should also consider combining effective interventions as a multi-modal approach to further reduce the risk of EA.

Dexmedetomidine for preventing sevoflurane-related emergence agitation in children: a meta-analysis of randomized controlled trials

Emergence agitation (EA) is a common problem after sevoflurane anesthesia in children. Prophylactic dexmedetomidine has been directed at this issue; however, the efficacy remains controversial. We therefore conducted a meta-analysis of randomized controlled trials (RCTs) to evaluate the effectiveness of dexmedetomidine on the incidence of sevoflurane-related EA. A comprehensive literature search was performed to identify RCTs that compared dexmedetomidine with placebo about the reduction in the incidence of sevoflurane-related EA for children. Heterogeneity between studies was anticipated; therefore, random effects models were chosen to calculate the pooled risk ratio (RR) and 95% confidence interval (CI), and I(2) statistics were used to assess statistical heterogeneity. The funnel plot and Egger test were used to assess potential publication bias. Subgroup analysis was run to explore the possible effects of age, surgical procedure, regional block/local anesthetics, supplemental analgesic, propofol, N2O, pre-medication and methodological quality on the incidence of EA using dexemedetomidine. Totally, 15 RCTs were included (518 patients received dexmedetomidine and 413 had placebo). Dexmedetomidine reduced the incidence of sevofurane-related EA (pooled RR = 0.351; 95% CI: 0.275-0.449; P = 0.965; heterogeneity test, I(2) = 0.0%), and it also resulted in a lower incidence of severe EA (pooled RR = 0.119; 95% CI: 0.033-0.422; P = 0.962; heterogeneity test, I(2) = 0.0%). All subgroup analyses for potential sources of heterogeneity showed a lower incidence of sevoflurane-related EA after dexmedetomidine administration. This meta-analysis demonstrated that dexemedetomidine was effective in reducing the incidence of sevoflurane-induced EA in children as compared with placebo.

Prophylactic midazolam and clonidine for emergence from agitation in children after emergence from sevoflurane anesthesia: a meta-analysis

BACKGROUND

Emergence agitation (EA) after emergence from sevoflurane anesthesia is a common phenomenon in children. The efficacy of prophylactic midazolam or clonidine in preventing EA is controversial.

OBJECTIVE

We performed a meta-analysis of clinical trials of the 2 drugs to evaluate their ability to prevent EA in pediatric patients after emergence from sevoflurane anesthesia.

METHODS

A comprehensive literature search was conducted to identify clinical trials that observed the effect of midazolam and clonidine on preventing EA in children after their emergence from sevoflurane anesthesia. All data were examined using the Mantel-Haenszel model to calculate the pooled odds ratio (OR) and 95% CI. I(2) was used to assess heterogeneity. Subgroup analysis was used to assess the effects of preoperative analgesics, routes of administration, and dose, and funnel plots were used to check publication bias.

RESULTS

After a comprehensive literature search, we found 12 papers that met the criteria for inclusion in this analysis, with a total of 447 children in the midazolam group and 767 children in the clonidine group. We found that both midazolam and clonidine decreased the incidence of EA (OR = 0.45 [95% CI, 0.29-0.70], P = 0.0004, I(2) = 46%; and OR = 0.24 [95% CI, 0.13-0.43], P < 0.00001, I(2) = 48%, respectively). Subgroup analysis indicated that preoperative analgesia may decrease the effect of midazolam against EA, whereas for clonidine, neither the route of administration (intravenous or caudal) nor the dose affected the results. Funnel plots did not detect publication bias in the midazolam group, but a bias was detected in the clonidine group.

CONCLUSIONS

This meta-analysis suggests that prophylactic administration of midazolam or clonidine could significantly decrease the incidence of sevoflurane-induced EA in pediatric patients.

Alpha-2-agonists in day case anaesthesia

PURPOSE OF REVIEW

Alpha-2-agonists have long been known to have anaesthetic-sparing, sedative and analgesic properties which are desirable in day case anaesthesia. Their routine use was hampered by a high incidence of undesirable effects, however. In recent years, there have been many attempts to define a role for these unique agents in which their benefits would outweigh their apparent disadvantages.

RECENT FINDINGS

Many recent studies have confirmed the usefulness of alpha-2-agonists in providing sedation and analgesia, although the results have been far from consistent. Some, but by no means all studies have shown advantages over alternative agents, but concerns also remain over acute and possible long-term adverse effects.

SUMMARY

Alpha-2-agonists still have no clearly defined routine role in day surgery. Their most promising application is in limiting recovery agitation in children, but even here, there remain concerns about their routine use.