Postanaesthesia excitation

Facial expressions of pain in daily clinical practice to assess postoperative pain in children: Reliability and validity of the facial action summary score

BACKGROUND

Behavioural pain scales are recommended to assess postoperative pain for children who are too young to use self-report tools. Their main limitation is underestimation of pain in the days following an intervention. Although relevant, facial expression is not used in daily clinical practice. This prospective study aimed to assess the validity and reliability of the Facial Action Summary Score (FASS), a five-item scale, to assess postoperative pain until hospital discharge in children <7 years.

METHODS

Assessments of pain and anxiety of 123 children using FASS and validated scales were used to study the psychometric validity of the FASS in clinical practice.

RESULTS

The content validity was previously investigated in a development study. The internal validity of the FASS was high with excellent reliability (intraclass coefficient = 0.94) and a high Cronbach α (0.89). Convergent validity with pain scales (FLACC [Face, Legs, Activity, Cry, Consoling] and FPS-R [Faces Pain Scale - Revised]) was high (r > 0.8). Sensitivity to change was verified by a significant decrease in the score after rescue analgesia. For a threshold of 2/5, the FASS shows excellent specificity (97%) and sensitivity (82%). The low number of false negatives is the main strength of this tool.

CONCLUSIONS

This work highlights the interest in using facial expression in daily clinical practice to manage postoperative pain. The FASS is easy to use with excellent psychometric properties and is particularly sensitive to measure pain in the days following surgery.

SIGNIFICANCE

The aim of this study was to prove that facial expression of pain can be used in clinical practice to measure postoperative pain in children. The reduced number of false negatives is the main strength of this tool.

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.

Comparison of the incidence of emergence agitation and emergence times between desflurane and sevoflurane anesthesia in children: A systematic review and meta-analysis

BACKGROUND

The differences in the incidence and severity of emergence agitation (EA) and emergence times between desflurane and sevoflurane anesthesia have not been as clearly elucidated in children as in adults.

METHODS

The design of the study is a systematic review with meta-analysis of randomized controlled trials. The study methodology is based on the Cochrane Review Methods. A comprehensive literature search was conducted to identify clinical trials comparing the incidence or severity of EA and emergence times in children anesthetized with desflurane or sevoflurane. Two reviewers independently assessed each study according to predefined inclusion criteria and extracted data from each study using a prespecified data extraction form. The data from each study were combined using a fixed effect or random effect model to calculate the pooled risk ratio (RR) or standardized mean difference (SMD) and 95% confidence interval (CI). Funnel plots were used to assess publication bias. Subgroup and sensitivity analyses were performed.

RESULTS

Fourteen studies met the inclusion criteria. Among the 1196 patients in these 14 studies, 588 received desflurane anesthesia and 608 received sevoflurane anesthesia. The incidence of EA was comparable between the 2 groups (pooled RR = 1.21; 95% CI: 0.96-1.53; I = 26%), and so was the severity of EA (EA score) between the 2 groups (SMD = 0.12; 95% CI: -0.02 to 0.27; I = 0%). Extubation and awakening times were shorter in the desflurane group than in the sevoflurane group; the weighted mean differences were -2.21 (95% CI: -3.62 to -0.81; I = 93%) and -2.74 (95% CI: -3.80 to -1.69; I = 85%), respectively. No publication bias was found in the funnel plot. The subgroup analysis based on the type of EA scale showed a higher incidence of EA in the desflurane group than in the sevoflurane group in studies using 3-, 4-, or 5-point EA scales; the pooled RR was 1.38 (95% CI: 1.10-1.73; I = 37%).

CONCLUSION

The incidence and severity of EA were comparable between desflurane and sevoflurane anesthesia in children; however, emergence times, including extubation and awakening times, were shorter in desflurane anesthesia.

Considerations when using pharmacokinetic/pharmacodynamic modeling to determine the effectiveness of simple analgesics in children

INTRODUCTION

Assessment of analgesic drugs includes comparative studies to other analgesics and local anesthesia blockade, number needed to treat estimates and opioid sparing descriptions. An additional methodology is to define the concentration-response relationship using pharmacokinetic/pharmacodynamic (PK/PD) modeling.

AREAS COVERED

A concentration-response relationship allows analgesic effect comparison between drugs for different acute pain types. Covariates such as size, age and organ function impact greatly on PK in children. The cumulative effect of confounding factors (e.g., pharmacogenetics, placebo and changes in baseline pain over time) complicates PD. Other factors (outcome measures, method of measurement, failure to account for study attrition) impact on outcome. Population PK/PD modeling approaches allow us to account for these various factors to some extent.

EXPERT OPINION

Nonlinear mixed effects models help interpret analgesic data and their use is increasing. The PK is relatively well understood. The next investigative step will involve investigation into covariate effects for PD. Mathematical functions for both placebo models and dropout models are well described and should be incorporated into analgesic effectiveness studies that investigate a range of doses. Improvements in pain assessment tools and a greater understanding of pharmacogenomics factors will help individualize analgesic therapy.

Appropriate dose of dexmedetomidine for the prevention of emergence agitation after desflurane anesthesia for tonsillectomy or adenoidectomy in children: up and down sequential allocation

Background

Dexmedetomidine can be used for the prevention of emergence agitation (EA) in children. However, an inadequate dose of dexmedetomidine can induce prolonged sedation and cardiovascular complications. The aim of this study was to evaluate the effective dose of dexmedetomidine for the prevention of EA after desflurane anesthesia for patients undergoing a tonsillectomy or adenoidectomy.

Methods

We enrolled 21 unpremedicated children, between 2 and 12 years, undergoing either a tonsillectomy or an adenoidectomy. General anesthesia was induced using sevoflurane and oxygen, and dexmedetomidine was administered before surgery. Anesthesia was maintained using desflurane resulting in a BIS range of 40–60. In the postanesthetic care unit (PACU), EA (agitation measured at level 4 or more at least once) was assessed on arrival in the PACU,15 min later, and 30 min later. The dose of dexmedetomidine for consecutive patients was determined by the response of the previous patient, using an increment or decrement of 0.1 μg/kg.

Results

The 50 % effective dose of dexmedetomidine for prevention of EA was 0.25 μg/kg (95 % confidence limits, 0.17–0.33 μg/kg), and the 95 % effective dose was 0.38 μg/kg (95 % confidence limits, 0.29–0.39 μg/kg).

Conclusions

For prevention of EA after desflurane anesthesia for 50 % and 95 % of children undergoing tonsillectomies or adenoidectomies, 0.25 μg/kg or 0.38 μg/kg of dexmedetomidine is suggested. Further study is needed to validate the suggested dose of dexmedetomidine to prevent the EA that was identified in the present study.

Trial registration

Clinical Research Information Service KCT0000126.

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.

Comparison of emergence agitation between sevoflurane/nitrous oxide administration and sevoflurane administration alone in children undergoing adenotonsillectomy with preemptive ketorolac

Background

Sevoflurane anesthesia commonly causes emergence agitation (EA) in children. One previous study has reported that the use of nitrous oxide (N₂O) during the washout of sevoflurane may reduce EA by decreasing the residual sevoflurane concentration, while many animal studies suggest that N₂O poses a potential risk to children. The present study was designed to compare EA in children assigned to receive sevoflurane with N₂O (group N) or sevoflurane alone (group S).

Methods

We enrolled 80 children aged 3-10 years. Anesthesia was induced with 5 mg/kg thiopental sodium, 0.6 mg/kg rocuronium and 0.5 mg/kg ketorolac, and was maintained with 50% N₂O and sevoflurane in group N or with sevoflurane alone in group S. The sevoflurane concentration was adjusted with a bispectral index (BIS) of 40-60. After completion of the surgery, N₂O and sevoflurane were simultaneously discontinued and replaced with oxygen (O₂) at 6 L/min. End-tidal sevoflurane concentration (Et Sevo) (%), BIS at the end of surgery, Et Sevo at recovery of self-respiration and emergence profiles were recorded. EA occurrence, pain score and rescue fentanyl consumption were assessed in the postanesthesia care unit.

Results

Et Sevo was significantly lower in group N (1.9%) than in group S (2.3%) at the end of surgery. However, there were no differences in Et Sevo at recovery of self-respiration, emergence times, the incidence of EA, pain score or dose of rescue fentanyl between the groups.

Conclusions

In children undergoing adenotonsillectomy with preemptive ketorolac, anesthetic maintenance using sevoflurane alone does not affect the incidence of EA or emergence profiles compared to anesthetic maintenance using sevoflurane with N₂O.

Propofol-remifentanil or sevoflurane for children undergoing magnetic resonance imaging? A randomised study

BACKGROUND

Magnetic resonance imaging (MRI) of children is generally performed under sedation or with general anaesthesia (GA), but the ideal regimen has not been found. The aim of this study was to see if propofol-remifentanil would be a suitable alternative for the maintenance of anaesthesia in this category of patients.

PATIENTS AND METHODS

Children aged 1-10 years, American Society of Anesthesiologists physical status 1-2 were included. After induction with thiopental or sevoflurane, the children were randomised to maintenance of anaesthesia with an infusion of propofol and remifentanil (group PR) (56 μg/kg/min of propofol and 0.06 μg/kg/min of remifentanil) or with sevoflurane 1.3 MAC (group S). A binasal catheter was placed in group PR and a laryngeal mask airway in group S. The children breathed spontaneously. The Paediatric Anaesthesia Emergence Delirium (PAED) score (primary end point), the number of movements during MRI, and the length of stay in the recovery room (secondary endpoints) were recorded.

RESULTS

Sixty children were included in each group. A lower level of emergence delirium (measured as a lower PAED score) was found in group PR compared with group S, and the children in group PR were discharged earlier from the recovery room than the children in group S. However, 15 children in group PR vs. 0 in group S moved during the scan (P < 0.001).

CONCLUSION

The PR infusion ensured a satisfactory stay in the recovery room, but additional boluses were necessary during the MRI. Sevoflurane was reliable during the MRI, but emergence delirium was a concern.

Emergence delirium in children: a comparison of sevoflurane and desflurane anesthesia using the Paediatric Anesthesia Emergence Delirium scale

OBJECTIVES/AIM

This randomized control trial was designed to evaluate the incidence of emergence delirium (ED) in preschool children receiving sevoflurane or desflurane anesthesia combined with an effective caudal block.

BACKGROUND

While ED has been described in children receiving sevoflurane or desflurane anesthesia, a direct comparison between the two agents using a validated ED assessment tool has not been reported previously.

METHODS/MATERIALS

Two hundred and sixty preschool children scheduled for elective sub-umbilical surgery were randomized to receive sevoflurane or desflurane anesthesia combined with a caudal block. ED was defined as a Paediatric Anesthesia Emergence Delirium scale (PAED) ≥ 10 points. A delirium-specific score (ED I) was calculated from the first three items of the PAED score (eye contact, purposeful actions, awareness of the surroundings) and a nonspecific score (ED II) from the last two items on the PAED score (restlessness and inconsolability) to test the hypothesis that some items of the PAED scale may better reflect clinical ED than others.

RESULTS

Thirty-one (25%) children in each group demonstrated ED after awakening with ED being of shorter duration in the desflurane group than the sevoflurane group. An ED I score of nine points had a sensitivity of 0.93 and a specificity of 0.94 for ED. An ED II score of five points had a sensitivity of 0.34 and specificity of 0.95 for ED.

CONCLUSION

Sevoflurane and desflurane anesthesia were associated with similar incidences of ED in children undergoing sub-umbilical surgery and receiving effective regional anesthesia. High scores on the first three items of the PAED scale were highly correlated with ED. The items restlessness and inconsolability had lower sensitivity for the diagnosis of ED.

Emergence agitation in children undergoing adenotonsillectomy: a comparison of sevoflurane vs. sevoflurane-remifentanil administration

BACKGROUND

Sevoflurane is widely used in paediatric anaesthesia but frequently causes emergence agitation (EA). This study evaluated whether limiting the sevoflurane concentration by combining remifentanil with sevoflurane reduced the incidence of EA.

METHODS

Eighty-four preschool children scheduled for adenotonsillectomy were randomly assigned to either the remifentanil or sevoflurane group. In the remifentanil group, anaesthesia was induced with thiopental, rocuronium, and 1% sevoflurane. It was maintained with 1% sevoflurane, 60% nitrous oxide in oxygen, and a continuous infusion of remifentanil. For the sevoflurane group, anaesthesia was induced with thiopental, rocuronium, and 8% sevoflurane, and was maintained with 2-3% sevoflurane. Both groups received ketorolac 1 mg/kg and dexamethasone 0.15 mg/kg. EA was measured using the paediatric anaesthesia emergence delirium (PAED) scale and a four-point EA scale in the post-anaesthesia care unit.

RESULTS

The scores on the PAED scales were significantly lower in the remifentanil group than in the sevoflurane group [median (interquartile range); 6 (4.25-10.25) vs. 11 (7.75-14.0), P = 0.007], and the proportion of patients with PAED scores ≥ 10 was significantly lower in the remifentanil group than in the sevoflurane group [15 (35.7%) vs. 27 (64.2%), P = 0.009]. The incidence of EA evaluated using the four-point scale was also lower in the remifentanil group [11 (26.1%) vs. 21 (50%), respectively, P = 0.025].

CONCLUSION

The incidence of EA was lower in children undergoing adenotonsillectomy who received a lower concentration of sevoflurane combined with remifentanil than in those given a higher concentration of sevoflurane without remifentanil.

Postoperative agitation in preschool children following emergence from sevoflurane or halothane anesthesia: a randomized study on the forestalling effect of midazolam premedication versus parental presence at induction of anesthesia

OBJECTIVE

The effect of midazolam premedication on forestalling postoperative agitation in children is not yet concluded. The purpose of this study was to compare the effects of midazolam premedication and parental presence during anesthetic induction on the incidence of postoperative agitation in pediatric patients.

METHODS

One hundred sixty-seven children between 2 years and 7 years of age, undergoing anesthesia for outpatient surgery, were enrolled and randomly divided into four groups: sevoflurane anesthesia with parental presence without premedication, sevoflurane anesthesia with oral midazolam premedication, halothane anesthesia with parental presence without premeditation, and halothane anesthesia with oral midazolam premedication. The children randomized to the premedication groups took oral midazolam 0.5mg/kg 20-30 minutes before anesthetic induction. For patients in the groups without premedication, one of the parents was present throughout the induction of anesthesia. One recovery room nurse blinded to the group assignment observed the patients and recorded the agitation scores all through their stay in the postanesthesia care unit.

RESULTS

Postoperative agitation was significantly less in patients who received halothane anesthesia with oral midazolam premedication (p<0.002).

CONCLUSION

Based on our data, the presence of a parent at induction of sevoflurance anesthesia was as effective as midazolam premedication in decreasing the incidence of postoperative agitation. Midazolam premedication, however, decreased postoperative agitation when halothane was used as the anesthetic agent.

Effects of aminophylline on cognitive recovery after sevoflurane anesthesia

PURPOSE

Aminophylline accelerates the recovery from sevoflurane anesthesia. We studied the effects of escalating doses of aminophylline on cognitive and clinical recovery after sevoflurane anesthesia.

METHODS

After ethical approval and informed consent, 150 patients scheduled for elective surgery under sevoflurane-fentanyl anesthesia were randomly allocated to receive saline or 2, 3, 4 or 5 mg/kg of aminophylline (n = 30 for each) at the end of anesthesia (T (0)). Short Orientation Memory Concentration Test (SOMCT) scores, entropy values, end-tidal sevoflurane concentrations (EtSevo), times to eyes opening and extubation, respiratory rate (RR) and tidal volume (TV) were recorded.

RESULTS

Compared to placebo, patients receiving 2, 3, 4 and 5 mg/kg of aminophylline had higher SOMCT scores [median (25th percentile/75th percentile) 20.6 (19/23), 21.5 (21/22), 24.5 (24-25), 25.5 (25/26), respectively, vs. 13.5 (13/14) at 30 min after extubation, and 24 (22/26), 25 (24/26), 27.5 (27-28), 27.5 (27/28), respectively, vs. 18.5 (18/19) at 45 min after extubation], higher entropy values for the first 10 min after T (0), lower EtSevo for the first 4 min after T (0), shorter times to eyes opening [5 (4.0/6.0), 5 (4.0/6.0), 4 (2.0/5.5), and 4 (2.0/6.0), respectively, vs. 9.8 (8.0/11.0) min], shorter times to extubation, shorter times to home discharge (P < 0.001), and higher RR and larger TV values. Patients who received 4 and 5 mg/kg of aminophylline showed higher SOMCT scores, 6 min shorter times to eyes opening and to extubation, and 58 min shorter times to home discharge.

CONCLUSION

The administration of escalating doses of aminophylline accelerates postoperative cognitive recovery from sevoflurane anesthesia, as measured by the SOMCT, due to increased ventilatory elimination of sevoflurane.

Efficacy of different concentrations of sevoflurane administered through a face mask for magnetic resonance imaging in children

BACKGROUND

The main aim of this study was to use a non-invasive method such as a face mask to maintain anesthesia in children during magnetic resonance imaging (MRI). The secondary aim was to ascertain hemodynamic-respiration parameters, recovery time and complications of anesthesia with the administration of different concentrations of sevoflurane.

METHODS

This prospective and randomized study included 96 ASA I-II children, aged 1-10, scheduled to undergo MRI with anesthesia with sevoflurane through a face mask. All patients were administered midazolam 0.5 mg·kg(-1) orally 30 min before anesthesia induction. Sevoflurane 8% was given to induce anesthesia under assisted-controlled ventilation for 2 min, and an intravenous route was opened on the hand. Three different concentrations of sevoflurane were administered through a face mask under spontaneous respiration to maintain anesthesia. A mixture of sevoflurane, oxygen, and air of 5 l·min(-1) was given through a face mask for anesthesia. Group 1 (n = 32) received 1.5% sevoflurane, Group 2 (n = 32) 1.25% sevoflurane, and Group 3 (n = 32) 1.0% sevoflurane. Recovery time, removal from the MRI room, postanesthesia care unit discharge data, and complications were also recorded. Heart rate, mean arterial pressure (MAP), peripheral oxygen saturation (SpO(2)), respiration rate, and anesthesia adequacy were recorded every 5 min from the time of induction until completion of the MRI.

RESULTS

All three groups were similar in demographic and hemodynamic respiratory features. MRI was successfully performed in 96.6% of all patients without additional intervention. Sevoflurane concentrations were increased for a short time in one patient in Group 1 and in two patients in Group 3. Oxygen flow was increased in one patient in Group 1 and in one patient in Group 2 as SpO(2) was lower than 95%. The mean time to eye opening (from discontinuation of sevoflurane to eye opening) was 155.8 ± 50.0 s in Group 1, 89.5 ± 16.0 s in Group 2, and 53.5 ± 10.0 s in Group 3; differences between the groups were statistically significant (P = 0.001). Airways were not used on any of the patients, and none vomited or required endotracheal intubation or laryngeal mask anesthesia.

CONCLUSIONS

We believe that the administration of sevoflurane at a concentration of 1% via a face mask under spontaneous respiration may provide light anesthesia without complications to induce an unarousable sleep for children during MRI.

Pharmacological prevention of sevoflurane- and desflurane-related emergence agitation in children: a meta-analysis of published studies

BACKGROUND

Emergence agitation (EA) in children is increased after sevoflurane anaesthesia. The efficacy of prophylactic treatment is controversial. The aim of this study was to provide a meta-analysis of the studies of the pharmacological prevention of EA in children.

METHODS

A comprehensive literature search was conducted to identify clinical trials that focused on the prevention of EA in children anaesthetized with sevoflurane, desflurane, or both. The data from each trial were combined using the Mantel-Haenszel model to calculate the pooled odds ratio (OR) and 95% confidence interval. I(2) statistics were used to assess statistics heterogeneity and the funnel plot and the Begg-Mazumdar test to assess bias.

RESULTS

Thirty-seven articles were found which included a total of 1695 patients in the intervention groups and 1477 in the control ones. Midazolam and 5HT(3) inhibitors were not found to have a protective effect against EA [OR=0.88 (0.44, 1.76); OR=0.39 (0.12, 1.31), respectively], whereas propofol [OR=0.21 (0.16, 0.28)], ketamine [OR=0.28 (0.13, 0.60)], alpha(2)-adrenoceptors [OR=0.23 (0.17, 0.33)], fentanyl [OR=0.31 (0.18, 0.56)], and peroperative analgesia [OR=0.15 (0.07, 0.34)] were all found to have a preventive effect. Subgroup analysis according to the peroperative analgesia given does not affect the results.

CONCLUSIONS

This meta-analysis found that propofol, ketamine, fentanyl, and preoperative analgesia had a prophylactic effect in preventing EA. The analgesic properties of these drugs do not seem to have a role in this effect.

Physostigmine and anaesthesia emergence delirium in preschool children

BACKGROUND

A significant proportion of preschool children experiences severe emergence agitation after anaesthesia. The symptoms of disorientation, restlessness, inconsolable crying and thrashing resemble an acute psychosis similar to an agitated central anticholinergic syndrome. The primary aim of this randomized controlled study was to assess the efficiency of the cholinesterase-inhibitor physostigmine in these children and to identify adverse effects.

METHODS

We anaesthetized 211 children (1-5 yr) with sevoflurane after midazolam premedication for varying operative procedures. Multimodal intraoperative and prophylactic pain therapy combined alfentanil, piritramide, diclofenac and regional/local bupivacaine. A 5-step score assessed emergence agitation. Severely agitated children were treated immediately with physostigmine (30 mug kg-1) or placebo in a randomized, double-blind fashion. The primary variable was the agitation score after 5 min.

RESULTS

Severe delirium occurred in 19% of all children. Five minutes following injection, severe agitation was still present in 10 out of 20 patients treated with physostigmine and 16/20 with placebo. This difference did not reach statistical significance (P = 0.1). Rescue therapy with intravenous propofol was given after 15 min of severe agitation to four children following physostigmine and nine following placebo (non-significant). An increased rate of postoperative nausea and vomiting (45% vs. 15%, P < 0.05) was the only adverse effect observed.

CONCLUSIONS

Severe emergence agitation might be related to a central anticholinergic syndrome as diagnosed empirically with a successful treatment with physostigmine. However, the results of this study do not support its routine use. The substance may augment the therapeutic options if injected slowly and after suitable prophylaxis to avoid postoperative nausea and vomiting.

Premedication of the pediatric patient – anesthesia for the uncooperative child

PURPOSE OF REVIEW

Inadequate handling of an uncooperative child preoperatively results in postoperative behavior problems. Premedication enables a calm induction and helps to decrease postoperative problems. Several premedicants will be covered in this review.

RECENT FINDINGS

Questions raised about the effects of oral midazolam use in children for premedication are now finding answers. New agents (dexmedetomidine and atypical antipsychotic agents) can be alternatives in premedication, especially in severely uncooperative children. The current literature highlights the missing information about the rather older premedicants.

SUMMARY

The benefits and disadvantages of new and older drugs should be weighed against each other, and decisions should be made according to the requirements of surgery, ward conditions and the severity of psychologic, developmental or mental disease. Further studies for the evaluation of the anxiolytic, sedative and antipsychotic drugs are still required.

Midazolam does not reduce emergence delirium after sevoflurane anesthesia in children

BACKGROUND

Behavioral disturbance in children following sevoflurane anesthesia is a relatively frequent event. The aim of this study was to evaluate whether a higher dose of preoperatively administered rectal midazolam compared with a lower would alleviate this phenomenon. Furthermore the impact of these two doses of midazolam on sedation at induction of anesthesia was compared.

METHODS

A total of 115 children presenting for minor surgery under anesthesia were included in the study. The children were randomized to receive rectally either 1 mg.kg(-1) midazolam (group H) or 0.5 mg.kg(-1) midazolam (group L). General anesthesia was induced with propofol or sevoflurane and maintained with 1.5% sevoflurane in the inspiratory limb. Prior to the start of surgery a regional block was performed to ensure adequate pain relief. Behavior on emergence was assessed using a three point scale. In case of severe agitation propofol was administered IV.

RESULTS

The children in group H were significantly better sedated preoperatively (P < 0.01). There was no significant difference in emergence behavior: 42.1% of children in group H compared with 36.2% of children in group L exhibited severe agitation requiring sedation with propofol (P = 0.37). However, regardless of the preoperative dose of midazolam more children under the age of 36 months (61.4%) were severely distressed at emergence compared with older children (16.7%) (P < 0.01).

CONCLUSIONS

A higher dose of 1 mg.kg(-1) rectal midazolam results in much better sedated children on induction of anesthesia than 0.5 mg.kg(-1). This, however, does not result in a reduced incidence of emergence delirium after sevoflurane anesthesia. Regardless of the premedication negative behavioral changes occur more frequently in children younger than 3 years of age.

Plasma and cerebrospinal fluid concentrations of indomethacin in children after intravenous administration

The objective of this study was to evaluate the cerebrospinal fluid (CSF) permeation of indomethacin in healthy children. The participants (n = 31, aged 4-144 months) received indomethacin (0.35 mg/kg) as a 10-minute intravenous infusion prior to surgery under spinal anaesthesia. A single CSF and plasma sample from each individual was collected 14 to 225 minutes after the infusion. Indomethacin concentrations were determined from the CSF, plasma, and protein-free plasma. Total plasma, protein-free plasma, and CSF concentrations of indomethacin ranged between 90 and 2200 ng/mL (median, 780 ng/mL), 0.3 and 0.8 ng/mL (median, 0.5 ng/mL), and 0.2 and 5.0 ng/mL (median, 1.4 ng/mL), respectively. The CSF to plasma concentration ratio remained less than 0.01. There was no correlation between the administration time and CSF concentrations. Eleven children developed 12 nonserious adverse effects, from which 5 were central nervous system (CNS) effects (agitation). In conclusion, indomethacin permeated into the CSF of children, which enables both desired and adverse CNS effects of indomethacin.

[Propofol for paediatric patients in ear, nose and throat surgery. Practicability, quality and cost-effectiveness of different anaesthesia procedures for adenoidectomy in infants]

BACKGROUND

The aim of this study was an improvement in patient comfort, reduction of anaesthesia costs and room contamination by the use of propofol for adenoidectomy.

METHODS

A total of 103 infants (aged 1-5 years) undergoing elective adenoidectomy were randomized for anaesthesia with sevoflurane-nitrous oxide/oxygen (group 1), sevoflurane-air/alfentanil (group 2), alfentanil-propofol under induction with sevoflurane (group 3) or alfentanil-propofol (group 4).

RESULTS

Using propofol, postoperative agitation and emesis were significantly less and the anaesthesia costs as well as the need for analgesics was reduced compared to inhalative anaesthesia.

CONCLUSIONS

The use of propofol for preschool children undergoing ear, nose and throat (ENT) surgery seems to be advantageous because of less postoperative agitation, emesis and costs.

Isoflurane is associated with a similar incidence of emergence agitation/delirium as sevoflurane in young children--a randomized controlled study

BACKGROUND

Children may be agitated or even delirious especially when recovering from general anesthesia using volatile anesthetics. Many trials have focused on the newer agents sevoflurane and desflurane but for the widely used isoflurane little is known about its potential to generate agitation. We investigated the emergence characteristics of small children after sevoflurane or isoflurane with caudal anesthesia for postoperative pain control.

METHODS

After institutional approval and parental consent, anesthesia was randomly performed with sevoflurane (n = 30) or isoflurane (n = 29) in children at the age of 3.8 +/- 1.8 years during surgical interventions on the lower part of the body. After induction, all children received caudal anesthesia with bupivacaine (0.25%, 0.8 ml x kg(-1)). Postoperatively, the incidences of emergence agitation (EA) and emergence delirium (ED) were measured by a blinded observer using a ten point scale (TPS; EA = TPS > 5 ED = TPS > 7) as well as vigilance, nausea/vomiting and shivering.

RESULTS

The two groups were comparable with respect to demographic data, duration of surgery and duration of anesthesia. There were also no differences in the period of time from the end of surgery until extubation, duration of stay in the PACU, postoperative vigilance and vegetative parameters. Incidence of EA was 30% (9/30) for sevoflurane and 34% (10/29) for isoflurane during the first 60 min in the PACU (P = 0.785). Likewise, the incidence of ED was not different between the groups (20% and 24%, respectively).

CONCLUSIONS

In our randomized controlled study, we found no difference in the incidence of EA or ED between sevoflurane and isoflurane. Therefore, the decision to use one or the other should not be based upon the incidence of EA or ED.

Emergence Delirium in Children: Many Questions, Few Answers

The introduction of a new generation of inhaled anesthetics into pediatric clinical practice has been associated with a greater incidence of ED, a short-lived, but troublesome clinical phenomenon of uncertain etiology. A variety of anesthesia-, surgery-, patient-, and adjunct medication-related factors have been suggested to play a potential role in the development of such an event. Restless behavior upon emergence causes not only discomfort to the child, but also makes the caregivers and parents feel unhappy with the quality of recovery from anesthesia. Although the severity of agitation varies, it often requires additional nursing care, as well as treatment with analgesics or sedatives, which may delay discharge from hospital. To reduce the incidence of this adverse event, it is advisable to identify children at risk and take preventive measures, such as reducing preoperative anxiety, removing postoperative pain, and providing a quiet, stress-free environment for postanesthesia recovery. More clinical trials are needed to elucidate the cause as well as provide effective treatment.

The management of severe emergence agitation using droperidol

Emergence agitation can occur following recovery from general anaesthesia. The patient may exhibit aggressive behaviour, disorientation, agitation and restlessness. Untreated, this complication may result in significant morbidity. We report two cases where droperidol was successfully used in the management of severe emergence agitation. In the first case, droperidol was administered to prevent the occurrence of postoperative agitation in a patient known to suffer from this condition following previous general anaesthetics. In the second case, droperidol was used to treat emergence agitation in a morbidly obese patient with a difficult airway who was aggressive and difficult to restrain. Both of these patients remained calm and co-operative, with stable cardio-respiratory parameters, following the administration of droperidol and showed no further signs of agitation. We suggest that droperidol is an effective medication that may be used to prevent and treat severe emergence agitation due to its rapid sedative effect and minimal cardio-respiratory depression.

Emergence agitation in children: an update

PURPOSE OF REVIEW

In this review, the most recent and relevant developments in the field of emergence agitation in children, as related to its assessment, etiology, and management, are discussed.

RECENT FINDINGS

Studies have shown that a more specific assessment tool is needed to decrease measurement errors. Such scales have been developed recently and incorporate cognitive-related assessment items in addition to agitation behaviors. Young, emotional, impulsive and less social children with anxious parents undergoing head and neck surgery are identified to be at risk for the development of emergence agitation. Factors that may influence the occurrence of this postanesthetic behavior include the level of preoperative anxiety and premedication, anesthesia drugs, as well as awakening in a hostile environment and feeling pain. Management include ruling out all possible causes, such as physiologic compromise, physical discomfort and pain. Treatment of emergence agitation is usually not required since the condition is self-limiting. If unremitting, however, treatment with opioids, benzodiazepines or small doses of hypnotics may be required.

SUMMARY

It is recommended that children at high risk are identified in order to decrease their level of preoperative anxiety, to supplement low-solubility inhalational agents with adjuvant drugs, to prevent postoperative pain and to allow parents to be with their children during recovery from anesthesia.

Desflurane anesthesia after sevoflurane inhaled induction reduces severity of emergence agitation in children undergoing minor ear-nose-throat surgery compared with sevoflurane induction and maintenance

Emergence agitation may occur after general anesthesia with volatile anesthetics in children. We designed this study to examine the emergence behavior of children undergoing ear-nose-throat surgery after sevoflurane induction and desflurane maintenance versus both sevoflurane induction and maintenance using a recently published Pediatric Anesthesia Emergence Delirium (PAED) scale. In 38 premedicated children aged 12 mo to 7 yr mask induction with sevoflurane was performed and they were randomly assigned to receive either sevoflurane (n = 19) or desflurane (n = 19) for maintenance of general anesthesia. Time to tracheal extubation, modified Aldrete score, emergence behavior, recovery complications, and pain scores were assessed. The PAED scale showed a significant advantage for desflurane (6 [0-15] versus 12 [2-20], maximum total score of 20 for severe agitation). Time to extubation was significantly shorter with desflurane than with sevoflurane (5.4 +/- 1.4 versus 13.4 +/- 1.8 min). The modified Aldrete score on arrival in the postanesthesia care unit (PACU) was significantly lower in children receiving sevoflurane for maintenance. Time to discharge from PACU to normal ward and the incidence of adverse effects were not significantly different between the groups. In conclusion, the use of desflurane for maintenance of anesthesia after sevoflurane induction in children is associated with less severe emergence agitation and faster emergence times.

Paediatric anaesthesia and inhalation agents

Inhalation agents are amongst the mainstays of paediatric anaesthesia, as children are often induced by mask before venous access is obtained. Children do not like needles and obtaining venous access in an awake and moving child can be very demanding. Safety aspects are of particular importance in paediatric anaesthesia. Therefore, the possibility of monitoring end-tidal concentrations facilitates correct dosing in all patients, from the preterm infant weighing less than 1000 g to the adult-sized adolescent. For induction, sevoflurane has nearly universally replaced halothane, leading to increased cardiovascular safety. The main disadvantages of inhalation agents, especially sevoflurane and desflurane, are delirious behaviour and agitated states during emergence. In addition, there remains uncertainty regarding the relevance of the cerebral stimulating pattern of some of these agents. Inhalation anaesthesia has a long tradition, whereas the experience with propofol is comparatively small. The incidence and clinical relevance of the propofol infusion syndrome during clinical anaesthesia are still unknown. Inhalation anaesthesia is still considered to be the gold standard by the overwhelming majority of paediatric anaesthetists world-wide, however, intravenous techniques can be an attractive alternative in specific clinical situations.

Preoperative caudal block prevents emergence agitation in children following sevoflurane anesthesia

BACKGROUND

The frequency of emergence agitation in children is increased following sevoflurane anesthesia. However, controversies still exist concerning the exact etiology of this postanesthetic problem. Although this phenomenon is present with adequate pain relief or even following pain-free procedures, pain is still regarded as a major contributing factor.

METHODS

In a prospective, randomized, double-blind study, we enrolled 48 premedicated and calm 2-6-year-old children undergoing inguinal hernia repair. We assigned children to one of two groups: children assigned to the caudal group (n = 24) received a caudal block to supplement sevoflurane, while children assigned to the fentanyl group (n = 24) received a bolus injection of 1 microg kg(-1) intravenous fentanyl before skin incision to supplement sevoflurane. In the post anesthesia care unit, all children were received by their parent, and the incidence of emergence agitation and pain scores, as well as hemodynamic changes, were compared in both groups.

RESULTS

Forty-four children completed the study. In the fentanyl group, 59% of the children were agitated following emergence from anesthesia as compared to 4.5% in the caudal group (P < 0.001). Also, pain scores, mean values of heart rate and blood pressure as well as morphine requirement were significantly higher in the post anesthesia care unit in the fentanyl group compared to the caudal group.

CONCLUSION

Our results show that in children undergoing inguinal hernia repair, pain control with a preoperative caudal block as compared to intraoperative intravenous fentanyl significantly reduces the incidence of emergence agitation and pain scores following sevoflurane anesthesia.

Postoperative behavioral changes following anesthesia with sevoflurane

BACKGROUND

Behavioral disturbance following hospitalization is a relatively frequent event, some children still having negative behavioral changes (NBC) 1 month following their operation. Sevoflurane has a propensity to induce 'excitement' during induction of anaesthesia, and delirium in the immediate postoperative phase. The aim of this study was to evaluate whether this translates into prolonged behavioral change.

METHODS

A total of 120 children presenting for daycase surgical procedures under anesthesia were included in the study. Children were randomized to induction and maintenance of anesthesia with sevoflurane or halothane. No additional sedative drugs were administered. Postoperative behavioral change was assessed using the Post-Hospital Behavior Questionnaire (PHBQ) on postoperative days 1, 7 and 30.

RESULTS

The Sevoflurane group (n = 63) were more distressed on emergence of anesthesia than the Halothane group (n = 57) (P < 0.05). About 58.3, 46.8 and 38.3% of all children exhibited NBC on postoperative days 1, 7 and 30, respectively. There was no association between anesthetic agent and behavior. There was a significant relationship between decreasing age and NBC (P < 0.005).

CONCLUSIONS

Children anesthetized with sevoflurane exhibit more immediate postoperative distress than those anesthetized with halothane. This difference is not carried over into the longer posthospital period. Negative behavioral changes occur more frequently with decreasing age.

Oral ketamine premedication can prevent emergence agitation in children after desflurane anaesthesia

BACKGROUND

The purpose of the present study was to determine whether oral ketamine premedication affected the incidence of emergence agitation in children.

METHODS

Thirty minutes before induction of anaesthesia, 80 children who were undergoing adenotonsillectomy with or without bilateral myringotomy and insertion of tubes received either ketamine 6 mg.kg(-1) per oral in group K or sour cherry juice alone in group C. Anaesthesia was maintained with desflurane. Emergence and recovery times were recorded. Tramadol was used for postoperative analgesia. Fentanyl (1 microg.kg(-1)) was administered for the treatment of emergence agitation or severe pain that still continued after tramadol administration. Postoperative behaviour was evaluated using a 5-point agitation scale.

RESULTS

The incidence of emergence agitation was 56% in group C, and 18% in group K (P = 0.001). There was no significant difference with respect to emergence times except from time to eye opening that was significantly longer in group K (P < 0.0001).

CONCLUSION

Oral ketamine premedication reduced the incidence of postanaesthesia emergence agitation in children without delaying recovery.

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.

Assessing behaviour in children emerging from anaesthesia: can we apply psychiatric diagnostic techniques?

BACKGROUND

No standardized instrument exists for the systematic analysis of emergence behaviour in children after anaesthesia. Our purpose was to evaluate children's behaviour prior to anaesthetic induction and immediately upon emergence to develop an assessment tool using psychiatric terminology and techniques.

METHODS

This prospective study evaluated 25 children from 2 to 9 years of age for preanaesthetic psychosocial factors that might affect behaviour. Children's behaviour was observed from admission to the surgical unit through the induction of anaesthesia. All children received a standardized premedication and induction of anaesthesia. The maintenance anaesthetic was randomized to intravenous remifentanil or inhaled isoflurane. All children underwent repair of strabismus. We assessed the behaviour of children for 30 min upon emergence from anaesthesia for symptoms of pain, distress and delirium using an assessment tool we developed guided by the principles of psychiatry as described in Diagnostic and Statistical Manual of Mental Disorders (DSM-IV).

RESULTS

Using our assessment tool, 44% of children demonstrated altered behaviour on emergence; 20% demonstrated complex symptoms with characteristics of delirium. Children anaesthetized with isoflurane had significantly higher postanaesthesia behaviour assessment scores than those anaesthetized with remifentanil (P = 0.04). Age was a significant variable; children <62 months were more prone to altered behaviour than those >62 months (P = 0.02). Scores did not correlate with preanaesthetic risk factors including preexisting psychological or social variables or observed preanaesthetic distress. There was no delay in hospital discharge in children assessed as having altered behaviour.

CONCLUSIONS

This exploratory study suggests that postanaesthetic behaviour abnormalities with characteristics of distress or delirium can be categorized using known DSM-IV terminology; in our cohort this behaviour was dependent on age and anaesthetic technique.