Adult Emergence Agitation: A Veteran-Focused Narrative Review.

Emergence agitation (EA) is a self-limited state of psychomotor excitement during awakening from general anesthesia. EA is confined to the emergence period as consciousness is restored, which sharply distinguishes it from other postoperative delirium states. Sporadic episodes of EA may become violent with the potential for harm to both patients and caregivers, but the long-term consequences of such events are not fully understood. Current literature on EA in adults is limited to small-scale studies with inconsistent nomenclature, variable time periods that define emergence, a host of different surgical populations, and conflicting diagnostic criteria. Therefore, true incidence rates and risk factors are unknown. In adult noncardiac surgery, the incidence of EA is approximately 19%. Limited data suggest that young adults undergoing otolaryngology operations with volatile anesthetic maintenance may be at the highest risk for EA. Currently suggested EA mechanisms are theoretical but might reflect underblunted sympathetic activation in response to various internal (eg, flashbacks or anxiety) or external (eg, surgical pain) stimuli as consciousness returns. Supplemental dexmedetomidine and ketamine may be utilized for EA prevention. Compared to the civilian population, military veterans may be more vulnerable to EA due to high rates of posttraumatic stress disorder (PTSD) manifesting as violent flashbacks; however, confirmatory data are limited. Nonetheless, expert military medical providers suggest that use of patient-centered rapport tactics, PTSD trigger identification and avoidance, and grounding measures may alleviate hyperactive emergence phenomena. Future research is needed to better characterize EA in veterans and validate prophylactic measures to optimize care for these patients. This narrative review provides readers with an important framework to distinguish EA from delirium. Furthermore, we summarize current knowledge of EA risk factors, mechanisms, and adult management strategies and specifically revisit them in the context of veteran perioperative health. The anesthesiology care team is ideally positioned to further explore EA and develop effective prevention and treatment protocols.

Effect of ancillary drugs on sevoflurane related emergence agitation in children undergoing ophthalmic surgery: a Bayesian network meta-analysis.

BACKGROUND: The comparative efficacy of ancillary drugs on sevoflurane related emergence agitation (EA) in children undergoing ophthalmic surgery remains controversial. METHODS: The databases were retrieved in an orderly manner from the dates of their establishment to October, 2018, including PubMed, The Cochrane Library and Web of Science, to collect randomized controlled trials (RCT) of different anesthetic drugs combined with sevoflurane for ophthalmic surgery. Then a network meta-analysis was conducted using R and Stata 12.0 softwares. RESULTS: The meta-analysis showed that, in reducing sevoflurane related EA, dexmedetomidine, ketamine, propofol, fentanyl, midazolam, sufentanil, remifentanil and clonidine were superior to placebo (P < 0.05). The network meta-analysis showed that the effects of ancillary drugs combine with sevoflurane in reducing risk of EA in children undergoing ophthalmic surgery was superior to placebo: dexmedetomidine (OR = 0.17, 95% CrI 0.12-0.22), ketamine (OR = 0.30, 95% CrI 0.11-0.49), propofol (OR = 0.24, 95% CrI 0.09-0.63), fentanyl (OR = 0.16, 95% CrI 0.08-0.56), midazolam (OR = 0.20, 95% CrI 0.09-0.40), sufentanil (OR = 0.27, 95% CrI 0.14-0.41), remifentanil (OR = 0.18, 95% CrI 0.08-0.54) and clonidine (OR = 0.14, 95% CrI 0.07-0.41). The SUCRA of placebo, dexmedetomidine, ketamine, propofol, fentanyl, midazolam, sufentanil, remifentanil, clonidine were respectively 0.26, 77.93, 27.71, 42.8, 69.43, 52.89, 59.83, 57.62 and 61.53%. CONCLUSIONS: The effects of dexmedetomidine combine with sevoflurane in reducing risk of emergence agitation in children undergoing ophthalmic surgery was superior to other drugs.

The new kisspeptin derivative - kissorphin (KSO) - attenuates acute hyperlocomotion and sensitization induced by ethanol and morphine in mice.

Kissorphin (KSO) is a new peptide derived from kisspeptin-10. This peptide possesses neuropeptide FF (NPFF)-like biological activity in vitro; NPFF, in many cases, inhibits opioid and ethanol effects in rodents. Therefore, the current study explored the influence of KSO on acute ethanol- and morphine-induced hyperactivity, and on the development and expression of locomotor sensitization induced by these drugs. In the present study, sensitization to locomotor effects was induced by repeated exposure to ethanol (2.4 g/kg, intraperitoneally [i.p.], 1 × 4 days) or morphine (10 mg/kg, subcutaneously [s.c.], 1 × 7 days). We found that KSO (1-10 nmol/300 µL, intravenously [i.v.]) did not have an impact on locomotor activity of naïve mice. However, it reduced both acute ethanol- (10 nmol/300 µL) and morphine-induced hyperactivity (3 and 10 nmol/300 µL). Pretreatment of animals with KSO (10 nmol/300 µL), before every ethanol or morphine injection during development of sensitization or before the ethanol or morphine challenge, attenuated the development, as well as the expression of locomotor sensitization to both substances. Moreover, prior administration of the NPFF receptor antagonist RF9 (10 nmol/300 µL, i.v.) inhibited the ability of KSO (10 nmol/300 µL) to reduce the expression of ethanol and morphine sensitization. KSO given alone, at all used doses, did not influence the motor coordination measured via the rotarod test. The results from this study show that KSO effectively attenuated acute and repeated effects of ethanol and morphine. Thus, KSO possesses NPFF-like anti-opioid activity in these behavioral studies.

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.

Low-dose dexmedetomidine reduces emergence agitation after desflurane anaesthesia in children undergoing strabismus surgery.

PURPOSE: Emergence agitation (EA) is frequently observed in children undergoing general anaesthesia. This study tested whether the addition of an intra-operative low-dose infusion of dexmedetomidine to fentanyl treatment reduced the incidence of emergence delirium following desflurane anesthesia in children undergoing strabismus surgery. MATERIALS AND METHODS: A total of 96 children (1-5 years old) undergoing strabismus surgery were enrolled. Anaesthesia was induced with propofol and maintained with desflurane. After induction, fentanyl (1 µg/kg) was administered to all children. During surgery, patients were infused with 0.2 µg/(kg·h)⁻¹ dexmedetomidine (Group FD, n=47) or normal saline (Group F, n=47). Postoperative objective pain score (OPS), Paediatric Agitation and Emergence Delirium (PAED) score, and EA score were documented every 10 minutes in the post-anaesthesia care unit. RESULTS: There were no significant differences between the two groups in demographic characteristics and haemodynamic changes. The mean values of maximum EA, maximum PAED, and maximum OPS score were significantly lower in Group FD than in Group F at 0, 10, and 20 minutes after arrival at the post-anaesthesia care unit (p<0.001). The frequency of fentanyl rescue was lower in Group FD than in Group F (p<0.001). The incidence of severe EA was significantly lower in Group FD than in Group F (12.8% vs. 74.5%, p<0.001). CONCLUSION: Intra-operative low-dose infusion of dexmedetomidine in addition to fentanyl reduces EA following desflurane anaesthesia in children undergoing strabismus surgeries.

Comparison of the effects of 0.03 and 0.05 mg/kg midazolam with placebo on prevention of emergence agitation in children having strabismus surgery.

BACKGROUND: Midazolam has been widely studied for preventing emergence agitation. The authors previously reported that in children with sevoflurane anesthesia, intravenous administration of midazolam (0.05 mg/kg) before the end of surgery reduced the incidence of emergence agitation but prolonged the emergence time. This study was designed to test the hypothesis that a lower midazolam dose could suppress emergence agitation with minimal disturbance of the emergence time in children with sevoflurane anesthesia. METHODS: In this randomized, double-blind, placebo-controlled trial, 90 children (1 to 13 yr of age) having strabismus surgery were randomized to 1:1:1 to receive 0.03 mg/kg of midazolam, 0.05 mg/kg of midazolam, or saline just before the end of surgery. The primary outcome, the incidence of emergence agitation, was evaluated by using the pediatric anesthesia emergence delirium scale and the four-point agitation scale. The secondary outcome was time to emergence, defined as the time from sevoflurane discontinuation to the time to extubation. RESULTS: The incidence of emergence agitation was lower in patients given 0.03 mg/kg of midazolam (5 of 30, 16.7%) and patients given 0.05 mg/kg of midazolam (5 of 30, 16.7%) compared with that in patients given saline (13/of 30, 43.3%; P = 0.036 each). The emergence time was longer in patients given 0.05 mg/kg of midazolam (17.1 ± 3.4 min, mean ± SD) compared with that in patients given 0.03 mg/kg of midazolam (14.1 ± 3.6 min; P = 0.0009) or saline (12.8 ± 4.1 min; P = 0.0003). CONCLUSION: Intravenous administration of 0.03 mg/kg of midazolam just before the end of surgery reduces emergence agitation without delaying the emergence time in children having strabismus surgery with sevoflurane anesthesia.

Prophylactic use of midazolam or propofol at the end of surgery may reduce the incidence of emergence agitation after sevoflurane anaesthesia.

Sevoflurane is associated with a high incidence of emergence agitation in children. Midazolam and propofol have been examined with the aim of reducing emergence agitation after sevoflurane anaesthesia. However the effect of both drugs on emergence agitation is still controversial. Therefore we designed this study to measure the effect of midazolam or propofol at the end of surgery on emergence agitation during the recovery period. One hundred and one children, aged one to 13 years, undergoing strabismus surgery were enrolled in this randomised double-blind study. Anaesthesia was induced and maintained with sevoflurane in N2O/O2. Children were randomly assigned to receive midazolam 0.05 mg/kg (group M, n = 35), propofol 1 mg/kg (group P, n = 31) or saline (group S, n = 35). A four-point scale was used to evaluate recovery characteristics upon awakening and during the first hour after emergence from anaesthesia. The incidence of emergence agitation in group M was 42.9% (15/35), in group P 48.4% (15/31) and in group S 74.3% (26/35). The incidence of emergence agitation in groups M and P was significantly less than in group S. The emergence time was prolonged for patients in groups M and P compared to group S. There was no significant difference in the incidence of emergence agitation or in emergence times between the groups P and M. We conclude that propofol or midazolam administration before the end of surgery may be effective in reducing the incidence of emergence agitation in children undergoing strabismus surgery under sevoflurane anaesthesia.

Effects of hydroxyzine-midazolam premedication on sevoflurane-induced paediatric emergence agitation: a prospective randomised clinical trial.

BACKGROUND AND AIM: Anaesthesia with sevoflurane leads to a high prevalence of emergence agitation in paediatric patients. This study investigates the effects of combining hydroxyzine and midazolam on sevoflurane-induced emergence agitation in paediatric patients undergoing infraumbilical surgery with a caudal block. PATIENTS AND METHODS: Eighty-four children 1-7 years of age undergoing general anaesthesia with sevoflurane and caudal block were assigned to two groups. Children in group M (n = 42) were premedicated with 0.5 mg kg oral midazolam and children in group MH (n = 42) were premedicated with 0.5 mg kg oral midazolam and 1 mg kg hydroxyzine given 30 min before anaesthesia induction. A caudal epidural block was performed following anaesthesia induction. Induction quality, parental separation scores and emergence agitation were evaluated. Emergence agitation was evaluated with the PAED score (Paediatric Anesthesia Emergence Delirium) every 5 min during the first 30 min after admission to recovery room. Induction quality and parental separation were assessed with 4-point scores. Postoperative pain was evaluated with the 10-point Children's and Infants' Postoperative Pain Scale. RESULTS: Median parental separation (3 vs. 2; P = 0.01), induction quality (2 vs. 2; P = 0.03) and sedation scores (3 vs. 2; P = 0.003) were significantly better in the MH group compared to the M group. Median PAED score of group M (15) was higher than that of group MH (11; P < 0.001) and the number of children with PAED scores more than 16 was also higher in group M (n = 16) compared to group MH (n = 2; P < 0.001). None of the children had a pain score more than 3 throughout the study period. CONCLUSION: The incidence of sevoflurane-induced emergence agitation was significantly lower in children premedicated with a midazolam and hydroxyzine combination compared to those premedicated with midazolam only. Furthermore, the midazolam and hydroxyzine combination provided better premedication quality than midazolam alone.

Potential adverse effects of discontinuing psychotropic drugs. Part 3: Antipsychotic, dopaminergic, and mood-stabilizing drugs.

Abrupt discontinuation of antipsychotic drugs in patients with schizophrenia is associated with earlier, and often more severe, illness episodes than are seen with gradual discontinuation. Antipsychotic drugs can cause various abnormal motor syndromes, but abruptly stopping them has been associated with the seemingly paradoxical development of similar motor syndromes, such as withdrawal dyskinesias, parkinsonian symptoms, dystonias, and neuroleptic malignant syndrome. Dopamine-releasing and dopamine-agonist drugs are used to treat some of the motor syndromes caused by antipsychotic drugs, but their abrupt discontinuation can also be associated with abnormal syndromes. When antipsychotic drugs, lithium, or certain anticonvulsant drugs are used for treatment of bipolar disorder, rapid versus gradual discontinuation is more likely to lead to greater mood instability and manic relapse. If necessary, these medications should be gradually tapered to minimize all types of adverse discontinuation effects. Patients should be educated about the possible adverse effects of abrupt medication discontinuation.

Combination effect of low dose fentanyl and propofol on emergence agitation in children following sevoflurane anesthesia.

OBJECTIVE: To investigate the combination effect of low dose fentanyl and subhypnotic dose of propofol on emergence agitation in children receiving sevoflurane for adenotonsillectomy procedure. METHODS: After ethical approval, a prospective, randomized, clinical study was performed in Saad Specialist Hospital, Al-Khobar, Kingdom of Saudi Arabia in 2007-2008. One hundred and twenty children in physical status of I according to the American Society of Anesthesiologists, aged 2-6 years, scheduled for adentonsillectomy under general anesthesia were allocated into 3 groups randomly. Anesthesia was induced and maintained by sevoflurane in all groups. Children received 0.1 ml.kg-1 normal saline at the end of surgery in group C (n=40), 1.5 mcg.kg-1 fentanyl during induction, and 0.1 ml.kg-1 normal saline at the end of surgery in group F (n=40), and 1.5 mcg.kg-1 fentanyl during induction and 1 mg.kg-1 propofol at the end of surgery in group FP (n=40). Postoperative agitation was recorded, if any, for the first postoperative hour. RESULTS: Three groups were comparable with regard to demographic data. Twenty-one patients (53%) in the control group, 14 patients (35%) in group F and 7 (18%) patients in group FP experienced postoperative agitation. CONCLUSION: The combination of low dose fentanyl before surgery and propofol at the end of surgery decreases the incidence and level of emergence agitation in children after adenotonsillectomy procedure under sevoflurane anesthesia.

Propofol reduces the incidence of emergence agitation in preschool-aged children as well as in school-aged children: a comparison with sevoflurane.

PURPOSE: Young age is considered as one of the factors associated with emergence agitation (EA) following sevoflurane anesthesia. The relationship between EA following propofol anesthesia and young age has not yet been examined. This study was designed to compare the incidence of EA in younger children and older children following either propofol or sevoflurane anesthesia. METHODS: Ninety-six preschool-aged (2-5 years) children and 90 school-aged (6-11 years) children (American Society of Anesthesiologists [ASA] I or II) scheduled to undergo otorhinolaryngological surgery were randomly assigned to receive either propofol or sevoflurane. These children were divided into the following four groups: propofol-preschool (P-pre), sevoflurane-preschool (S-pre), propofol-school (P-school), and sevoflurane-school (S-school) groups. Recovery times and incidence of EA were compared among the four groups. RESULTS: We observed that the recovery times were similar in the four groups. After extubation, the incidence of EA in the S-pre group was significantly higher than that in the other groups. After eye opening, the incidence of EA in the S-pre and S-school groups was significantly higher than that in the P-pre or P-school groups. At all recovery times, no difference was observed in the incidence of EA between the P-pre and P-school groups. CONCLUSION: Propofol, in comparison with sevoflurane, resulted in a lower incidence of EA, with no relation to age.

Relating with professionals.

This paper addresses my difficulties as a carer in engaging with many professionals in mental health, both locally associated with my son's acute inpatient care, and nationally where policies are being developed and their implementation is pursued. All of us are affected by The Department of Health (DoH) Mental Health policies and their implementation by professionals has formed the way in which professionals relate with my son and myself. The way in which my son is impacted inextricably affects the way I relate to professionals. I think my difficulty in engaging lies in the relationships we all have with each another. In focusing on the process within our relationships, I attempt to raise professionals' awareness of what constitutes a relationship when we dialogue. As it takes two to engage in a dialogue, I perceive my difficulty is also the difficulty of the professionals. Carers are becoming increasingly involved in the training of mental health professionals and our combined difficulty needs to be resolved, so that we all benefit. In order to achieve positive progression, there needs to be a radical change within our relationship to provide ease of engagement from all parties. In this paper I tentatively suggest how this process can be achieved.

The prevention of emergence agitation with tropisetron or clonidine after sevoflurane anesthesia in small children undergoing adenoidectomy.

Postoperative agitation is a common problem after sevoflurane anesthesia in children. In the present study, we evaluated if tropisetron or clonidine could reduce the incidence of postoperative agitation after day case adenoidectomy in small children. We included 75 unpremedicated children aged 1-7 yr who were randomly assigned to receive either placebo, tropisetron (0.1 mg/kg) or clonidine (1.5 microg/kg) after anesthesia induction. Anesthesia was induced and maintained with sevoflurane. Patients also received alfentanil (20 microg/kg) and diclofenac (1 mg/kg). Postoperative pain was treated with IV oxycodone (0.05 mg/kg). Time to achieve discharge criteria was recorded. Modified pain/discomfort scale was used assess the postoperative behavior. The incidence of postoperative agitation was significantly less (32%, 8/25 patients) in the tropisetron group compared with placebo (62%, 16/26 patients), P < 0.05). Clonidine could not prevent agitation (incidence 54%, 13/24). No adverse effects were noted during the study. Discharge times were similar between the groups (between 80 and 99 min on average). In conclusion, tropisetron 0.1 mg/kg significantly reduced the incidence of postoperative agitation after sevoflurane anesthesia. Clonidine 1.5 microg/kg did not differ from placebo with respect to postoperative agitation.

Comparison of caudal and intravenous clonidine in the prevention of agitation after sevoflurane in children.

BACKGROUND: In children, sevoflurane anaesthesia is associated with postanaesthetic agitation, which is treated mainly with opioids. We compared the effectiveness of epidural and i.v. clonidine in the prevention of this postanaesthetic agitation. METHODS: Eighty children aged 3-8 yr (ASA I-II) received standardized general anaesthesia with inhaled sevoflurane and caudal epidural block with 0.175% bupivacaine 1 ml kg-1 for minor surgery. The children were assigned randomly to four groups: (I) clonidine 1 microgram kg-1 added to caudal bupivacaine; (II) clonidine 3 micrograms kg-1 added to caudal bupivacaine; (III) clonidine 3 micrograms kg-1 i.v. and caudal bupivacaine; and (IV) caudal block with bupivacaine, no clonidine (control). A blinded observer assessed the behaviour of the children during the first postoperative hour. Secondary end-points were the time to fitness for discharge from the postanaesthesia care unit, and haemodynamic and respiratory variables. RESULTS: The incidence of agitation was 22, 0, 5 and 39% in groups I, II, III and IV respectively (P < 0.05 for groups II and III compared with group IV). During the first hour after surgery, patients in groups II and III had significantly lower scores for agitation than group IV patients. Time to fitness for discharge did not differ between the four groups. CONCLUSIONS: Clonidine 3 micrograms kg-1 prevented agitation after sevoflurane anaesthesia, independently of the route of administration. The effect of clonidine appears to be dose-dependent, as an epidural dose of 1 microgram kg-1 failed to reduce it.

The incidence of emergence agitation associated with desflurane anesthesia in children is reduced by fentanyl.

UNLABELLED: The rapid emergence and recovery from general anesthesia provided by desflurane is associated with a frequent incidence of emergence agitation in children. We sought to determine the mean effective dose of fentanyl that would significantly reduce the incidence of emergence agitation while preserving rapid recovery. Thirty-two children undergoing adenoidectomy received general anesthesia with desflurane and a dose of fentanyl (1.25, 1.87, 2.8, and 4.2 microg/kg) determined by the classic up-down method. Recovery characteristics, including time to extubation, recovery, hospital discharge, agitation, pain, and vomiting, were recorded. Demographics and recovery features were assessed by analysis of variance and Kruskal-Wallis tests. The mean effective dose of fentanyl to reduce agitation was calculated with the Dixon-Massey method to be 2.5 +/- 6.2 microg. There were no significant differences when treatment groups were compared for recovery criteria. Postoperative emesis occurred in 75% of patients. The results of this study demonstrate that a dose of 2.5 microg/kg of fentanyl is sufficient to prevent emergence agitation while preserving the rapid recovery associated with desflurane anesthesia in children undergoing adenoidectomy. IMPLICATIONS: A dose of 2.5 microg/kg of fentanyl prevents emergence agitation associated with desflurane anesthesia in children undergoing adenoidectomy without delaying emergence.