Sevoflurane versus halothane: postoperative maladaptive behavioral changes: a randomized, controlled trial

BACKGROUND: The authors conducted a double-blind, randomized, controlled trial to determine whether the use of sevoflurane in children undergoing anesthesia and surgery results in a higher incidence of postoperative maladaptive behavioral changes as compared with halothane. METHODS: Children and their parents (n = 102) were randomly assigned to either a halothane group (n = 50) or a sevoflurane group (n = 52). The intraoperative anesthetic protocol was strictly controlled, and the postoperative analgesic consumption and pain levels were recorded. The effect of the group assignment on emergence status and maladaptive postoperative behavioral changes was assessed both by validated psychological measures and physiologic instruments (actigraphy) on postoperative days 1-7. Anxiety of the parent and child was also assessed, as was the child's postoperative recovery (Recovery Inventory). RESULTS: There were no group differences in preoperative state anxiety, postoperative analgesic requirements, postoperative pain, or the incidence of emergence delirium (P = not significant). Two-way repeated-measures analysis of variance showed no group differences in the incidence of postoperative maladaptive behaviors (F4,72 = 0.60, P = 0.701) or actigraphic variables such as percent sleep, number of night awakenings, and night awakenings that lasted for more than 5 min (P = not significant). CONCLUSION: The authors found no increased incidence of emergence delirium, maladaptive postoperative behavior changes, or sleep disturbances in children undergoing anesthesia with sevoflurane as compared with halothane.     

The effect of caudal analgesia on emergence agitation in children after sevoflurane versus halothane anesthesia

Sevoflurane anesthesia in young children has been associated with an increased incidence of emergence agitation compared with halothane. Postoperative pain may be an etiologic factor. We designed a study to compare the incidence of emergence agitation after halothane and sevoflurane anesthesia in children whose pain was managed with caudal analgesia. Eighty children undergoing inguinal hernia repair between the ages of 12 mo and 6 yr were randomly assigned to receive either halothane or sevoflurane anesthesia. Baseline preoperative anxiety was assessed with the Yale Preoperative Anxiety Scale. The children were sedated with oral midazolam, underwent a mask induction, and had a caudal block placed for postoperative analgesia. After surgery, the children's behavior was assessed with a four-point agitation scale. At 5 min after arrival in the postanesthesia care unit (PACU), sevoflurane was associated with a greater incidence of emergence agitation than halothane (26% vs 6%; P < 0.05), but not during the remainder of the PACU stay. Higher levels of preoperative anxiety were associated with difficult mask induction, agitation on admission to the PACU, and more severe agitation episodes. Emergence agitation appears to be an early and transient phenomenon after sevoflurane anesthesia in children with effective postoperative analgesia. IMPLICATIONS: Effective postoperative analgesia may reduce the incidence of emergence agitation reported with sevoflurane anesthesia. The Yale Preoperative Anxiety Scale appears to be helpful in identifying young children who are at risk for developing emergence agitation.     

Vomiting and common paediatric surgery

Postoperative vomiting is a common and unpleasant complication. The purpose of the present study was to verify if dexamethasone reduces the incidence of vomiting when injected IV in children anaesthetized with halothane for common paediatric operations. We also studied the incidence of vomiting when sevoflurane was used instead. Five hundred and 69 boys, aged 2-12 years (ASA physical status I, II), scheduled for inguinal field surgery were randomly assigned to receive halothane, halothane and dexamethasone and sevoflurane in three groups: halothane (n=180), halothane and IV dexamethasone (n=188) and sevoflurane (n=201). Anaesthesia was induced by inhalation of halothane or sevoflurane in oxygen and nitrous oxide and was maintained at minimum alveolar concentration of each agent throughout the surgery. For intra- and postoperative pain control iliac crest block was used in all the boys. Vomiting was defined as any expulsion of liquid gastric contents. The incidence of postoperative vomiting was 23% in the halothane group, which was significantly greater than that in the other groups (halothane and dexamethasone group, 9%; sevoflurane group, 13%). In conclusion, dexamethasone reduces the incidence and frequency of multiple emetic episodes when administered intravenously after halothane anaesthesia; sevoflurane reduces the overall incidence of vomiting, but not multiple emetic episodes.     

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.     

Greater Incidence of Delirium during Recovery from Sevoflurane Anesthesia in Preschool Boys

Background: In the authors' clinical experience, preschool children are more likely to show delirium after sevoflurane than are older children.

Methods: Sixty-three preschool boys aged 3-5 yr (classified as American Society of Anesthesiologists [ASA] physical status I), and 53 school-age boys aged 6-10 yr (ASA physical status I) who underwent minor urologic surgery were randomly assigned to receive either halothane or sevoflurane, thus creating four groups: preschool-halothane (n = 32), preschool-sevoflurane (n = 31), school-halothane (n = 27), and school-sevoflurane (n = 26). Anesthesia was induced by inhalation of halothane or sevoflurane in oxygen and was maintained at 1 minimum alveolar concentration of each agent throughout surgery. For intra- and postoperative analgesia, caudal block with 0.5-1.0 ml/kg 0.25% plain bupivacaine and topical infiltration with 3-5 ml 1% lidocaine were provided for all patients. Recovery characteristics and incidence of delirium on emergence were compared among the four groups.

Results: Two patients in the preschool-halothane group, one in the preschool-sevoflurane group, and one in the school-halothane group were excluded from the comparison because of insufficient analgesia or agitation before induction. In both age groups, the time to emergence from sevoflurane was significantly faster (about 3 min) than from halothane. The incidence of delirium during recovery in the preschool-sevoflurane group (40%) was significantly greater than that in the other groups (preschool-halothane, 10%; school-halothane, 15.4%; school-sevoflurane, 11.5%).     

Clinical Characteristics of Sevoflurane in Children: A Comparison with Halothane

Background: For pediatric patients, sevoflurane may be an alternative to halothane, the anesthetic agent used most commonly for inhalational induction. The induction, maintenance, and emergence characteristics were studied in 120 unpremedicated children 1-12 yr of age randomly assigned to receive one of three anesthesia regimens: sevoflurane with oxygen (group S), sevoflurane with nitrous oxide and oxygen (group SN), or halothane with nitrous oxide and oxygen (group HN).

Methods: Anesthetic was administered (via a Mapleson D, F or Bain circuit) beginning with face mask application in incremental doses to deliver maximum inspired concentrations of 4.5% halothane or 7% sevoflurane. End-tidal concentrations of anesthetic agents and vocal cord position were noted at the time of intubation. Elapsed time intervals from face mask application to loss of the eyelash reflex, intubation, surgical incision, and discontinuation of the anesthetic were measured. Heart rate, systolic, diastolic, and mean blood pressures, and end-tidal anesthetic concentrations were measured at fixed intervals. Anesthetic MAC-hour durations were calculated. The end-tidal concentration of anesthetic was adjusted to 1 MAC (0.9% halothane, 2.5% sevoflurane) for at least the last 10 min of surgery. Intervals from discontinuation of anesthetic to hip flexion or bucking, extubation, administration of first postoperative analgesic, and attaining discharge criteria from recovery room were measured. Venous blood was sampled at anesthetic induction, at the end of anesthesia, and 1, 4, 6, 12, and 18-24 h after discontinuation of the anesthetic for determination of plasma inorganic fluoride content.

Results: Induction of anesthesia was satisfactory in groups SN and HN. Induction in group S was associated with a significantly greater incidence of excitement (35%) than in the other groups (5%), resulting in a longer time to intubation. The end-tidal minimum alveolar concentration multiple of potent inhalational anesthetic at the time of intubation was significantly greater in patients receiving halothane than in patients receiving sevoflurane. Induction time, vocal cord position at intubation, time to incision, duration of anesthesia, and MAC-hour duration were similar in the three groups. During emergence, the time to hip flexion was similar among the three groups, whereas the time to extubation, time to first analgesic, and time to attaining discharge criteria were significantly greater in group HN than in groups S and SN. Mean heart rate and systolic blood pressure decreased during induction in group HN but not in groups S and SN. The maximum serum fluoride concentration among all patients was 28 micro Meter.     

Attenuation of the Preoperative Stress Response with Midazolam: Effects on Postoperative Outcomes

Background. Previously, effects of preoperative sedatives were assessed mainly with respect to preoperative outcomes such as anxiety and compliance. The purpose of this investigation was to evaluate the effects of preoperative sedatives on postoperative psychological and clinical recovery.

Methods: Patients undergoing general anesthesia and outpatient surgery were enrolled in a double-blind, randomized, placebo-controlled trial. Subjects (n = 55) were randomly assigned to receive either 5 mg intramuscular midazolam (n = 26) or a placebo injection (n = 29) at least 30 min before surgery. The anesthetic technique was controlled. Postoperative anxiety, pain, analgesic consumption, clinical recovery parameters, and global health (SF-36) were evaluated up to 1 month after surgery.

Results: Surgery length did not differ significantly between the treatment and placebo groups (118 +/- 45 min vs 129 +/- 53 min;P = NS). Throughout the first postoperative week, subjects in the treatment group reported a greater reduction in postoperative pain compared with subjects in the placebo group (F1,50= 3.5;P = 0.035). Moreover, at 1 week, ibuprofen use was reported by less subjects in the treatment group than in the placebo group (0%vs 17.2%;P = 0.026). Subjects in the treatment group also reported a greater reduction in postoperative anxiety throughout the follow-up period (F1,53 = 9.2;P = 0.04). However, global health indexes (SF-36) did not detect any significant differences between the two experimental groups (multivariate F1,45 = 0.44;P = 0.51).     

Dose-response study of preincisional buprenorphine on emergence time and postoperative analgesic requirement in patients anesthetized with sevoflurane

The effect of intravenous buprenorphine on emergence time from sevoflurane anesthesia and postoperative analgesic requirement was evaluated after otolaryngeal surgeries. Forty-five patients were randomly assigned to one of three treatment groups (n = 15 each): Control-group received saline as a control; 2 micrograms-group received buprenorphine 2 micrograms.kg-1; and 4 micrograms-group received buprenorphine 4 micrograms.kg-1, respectively. Study drug was administered intravenously at the induction of general anesthesia. Anesthesia was maintained with sevoflurane (1.5%) and nitrous oxide (66%) in oxygen. The pain score, postoperative analgesic requirement, and incidence of nausea and/or vomiting were examined. The emergence times were 16.4 +/- 3.5, 14.7 +/- 5.2, and 17.8 +/- 7.7 min [mean +/- SD], in the control-group, the 2 micrograms-group, and the 4 micrograms-group, respectively. There were no differences among the groups in term of the end-tidal sevoflurane concentration immediately before tracheal extubation. In the control-group, the 2 micrograms-group, and the 4 micrograms-group, 10, 1, and 3 patients, requested additional analgesics during the first 24 hours after surgery, respectively (control-group vs. 2 micrograms-group and 4 micrograms-group, P < 0.05). Nausea and vomiting occurred more frequently in the 2 micrograms-group and the 4 micrograms-group. We conclude that buprenorphine (2 or 4 micrograms.kg-1) reduced analgesic requirement during the first 24 hours after surgery without delaying emergence from sevoflurane anesthesia.     

Relative Amnesic Potency of Five Inhalational Anesthetics Follows the Meyer-Overton Rule

Background: Doses of volatile anesthetics around 0.3 minimum alveolar concentration (MAC) inhibit learning. However, threshold amnesic doses and relative potencies between agents are not well established. The authors determined amnesic potency in rats for four common volatiles and nitrous oxide.

Methods: After institutional review board approval, adult Sprague-Dawley rats received inhibitory avoidance training during exposure to either air or various subanesthetic doses of desflurane, sevoflurane, isoflurane, halothane, or nitrous oxide (4-21 rats/dose). Animals were trained to remain in a starting "safe" compartment for 100 consecutive seconds by administering a foot shock (0.3 mA) each time they entered an adjacent "shock" compartment. Memory was assessed at 24 h. Anesthetic effects on pain thresholds were separately determined.

Results: Learning: Only relatively higher doses of sevoflurane, halothane, and desflurane increased the number of shocks required for task acquisition. Memory: Significantly decreased retention performance (P < 0.05) was found at relatively low inspired concentrations of 0.2% isoflurane, 0.3% sevoflurane and halothane, 0.44% desflurane, and 20% nitrous oxide. Amnesic potency was nitrous oxide >= desflurane > sevoflurane >= isoflurane >> halothane, (rank-ordered ED50 values as %MAC). Amnesic potency correlated with oil:gas partition coefficients (r = -0.956, P < 0.007). Halothane, only at 0.08%, enhanced retention (P < 0.01). All agents were analgesic at higher doses.     

Preoperative Anxiolysis and Postoperative Recovery in Women Undergoing Abdominal Hysterectomy

Background: Every year, millions of patients receive sedatives for reduction of anxiety before surgery, but there is little objective data on the effect of this treatment on postoperative outcomes. To address this issue, the effects of benzodiazepine administration were evaluated in women undergoing abdominal surgery.

Methods: Patients were randomized to receive 1 mg of oral lorazepam the night before surgery and 5 mg of intramuscular midazolam on the morning of surgery (n = 34), or to receive a placebo the night before surgery and on the morning of surgery (n = 36). Postoperative pain (Visual Analogue Scale for pain, McGill Pain Questionnaire) and analgesic consumption (patient-controlled analgesia), and clinical recovery parameters such as time to discharge from hospital were evaluated after surgery.

Results: Patient-controlled analgesia use showed a marginal main effect of treatment group (F(1,51) = 2.8;P = 0.047). Post hoc analysis demonstrated that patient-controlled analgesia consumption was significantly lower in the treatment group only during the first 4 h of patient-controlled analgesia use after surgery (P = 0.027). There were no significant group differences at any later postoperative time points (P = not significant). There were no group differences in the cumulative Percocet (Pfizer, New York, NY) consumption in the postoperative period (P = not significant). Further, self-reported postoperative pain did not differ significantly between groups at any of the time points (P = not significant). There were also no group differences with regard to any postoperative clinical recovery parameters.     

Use of Intranasal Fentanyl in Children Undergoing Myringotomy and Tube Placement during Halothane and Sevoflurane Anesthesia

Background: Many children are restless, disoriented, and inconsolable immediately after bilateral myringotomy and tympanosotomy tube placement (BMT). Rapid emergence from sevoflurane anesthesia and postoperative pain may increase emergence agitation. The authors first determined serum fentanyl concentrations in a two-phase study of intranasal fentanyl. The second phase was a prospective, placebo-controlled, double-blind study to determine the efficacy of intranasal fentanyl in reducing emergence agitation after sevoflurane or halothane anesthesia.

Methods: In phase 1, 26 children with American Society of Anesthesiologists (ASA) physical status I or II who were scheduled for BMT received intranasal fentanyl, 2 [mu]g/kg, during a standardized anesthetic. Serum fentanyl concentrations in blood samples drawn at emergence and at postanesthesia care unit (PACU) discharge were determined by radioimmunoassay. In phase 2, 265 children with ASA physical status I or II were randomized to receive sevoflurane or halothane anesthesia along with either intranasal fentanyl (2 [mu]g/kg) or saline. Postoperative agitation, Children's Hospital of Eastern Ontario Pain Scale (CHEOPS) scores, and satisfaction of PACU nurses and parents with the anesthetic technique were evaluated.

Results: In phase 1, the mean fentanyl concentrations at 10 +/- 4 min (mean +/- SD) and 34 +/- 9 min after administering intranasal fentanyl were 0.80 +/- 0.28 and 0.64 +/- 0.25 ng/ml, respectively. In phase 2, the incidence of severe agitation, highest CHEOPS scores, and heart rate in the PACU were decreased with intranasal fentanyl. There were no differences between sevoflurane and halothane in these measures and in times to hospital discharge. The incidence of postoperative vomiting, hypoxemia, and slow respiratory rates were not increased with fentanyl.     

Recovery characteristics of propofol anesthesia in pediatric outpatients; comparison with sevoflurane anesthesia

We compared recovery characteristics of propofol anesthesia with those of sevoflurane anesthesia in pediatric outpatients. One hundred and four children, 3 months to 6 years of age, ASA physical status 1 or 2, were randomly assigned to following four groups; sevoflurane (group S), propofol (group P), sevoflurane with premedication (group MS), or propofol with premedication (group MP). Midazolam 0.5 mg.kg-1 and famotidine 1 mg.kg-1 were administered orally 30 min before the induction in the MS and MP group. Recovery from anesthesia, agitation, and postoperative pain were evaluated. The time intervals from the end of surgery to extubation and to discharge from the hospital were recorded. The incidence of vomiting and use of analgesic drugs were also checked. The emergence from anesthesia was slower with propofol anesthesia than with sevoflurane anesthesia, but the time to discharge from the hospital was not significantly different among the four groups. Incidence of agitation was higher in S group compared with P group, but there were no differences between MS and MP. Postoperative pain was similar among the four groups. There were no differences in the incidence of vomiting. Propofol anesthesia provided slower emergence and less agitation compared with sevoflurane anesthesia.     

Psychological and behavioral effects of chloral hydrate in day-case pediatric surgery: a randomized, observer-blinded study

Background/PurposeThis prospective, randomized, and observer-blinded study was performed to evaluate the effects of oral chloral hydrate on perioperative psychological and behavioral phenomena in children.MethodsIn total, 100 boys (age, 1-5 years) scheduled for day-case unilateral orchiopexy were randomly allocated into 2 groups and orally administered either 40 mg/kg of chloral hydrate (CH group) or placebo (control group) 30 minutes before surgery, followed by assessment of anxiety, induction compliance, emergence delirium, postoperative pain, and maladaptive behavioral changes.ResultsAnxiety scores were significantly lower in the CH group compared with the control group (45.7 vs 28.8). The induction compliance of the CH group was better than that of the control group (3.2 vs 4.8). Postoperative sedation was more frequent (62.7% vs 20.4%); however, the incidence of vomiting was lower (2.0% vs 14.3%) in the CH group than in the control group. Postoperative emergence delirium and maladaptive behavior changes were similar between the 2 groups.ConclusionDecreasing preoperative anxiety with oral chloral hydrate improves induction compliance and reduces postoperative pain intensity without delaying recovery in young boys. However, chloral hydrate had little impact on emergence delirium and postoperative maladaptive behavior.     

Reducing Pain after Inguinal Hernia Repair in Children: Caudal Anesthesia versus Ketorolac Tromethamine

Background: The optimal method to achieve analgesia after inguinal hernia repair in children is unknown. This study compared the analgesic efficacy, adverse events, and the costs associated with supplementation of local anesthesia (infiltration of the wound) with either intravenous ketorolac or caudal analgesia in children having inguinal hernia repair.

Methods: With parental consent and institutional review board approval, children aged 2-6 yr having elective, outpatient inguinal hernia repair were studied in this randomized, single-blinded investigation. Anesthesia was induced by inhalation with nitrous oxide and halothane or intravenously with propofol. Anesthesia was maintained with nitrous oxide and halothane. Patients were randomly assigned to receive caudal analgesia (1 ml/kg 0.20% bupivacaine with 1/200,000 epinephrine) or intravenous ketorolac (1 mg/kg) immediately after induction of anesthesia. Both groups received field blocks with 0.25% bupivacaine administered by the surgeon under direct vision during operation. Patients were assessed for 24 h. In-hospital pain was assessed using a behavior-based pain score. Parents assessed pain with a visual linear analog pain scale with anchors of 0 (no pain) and 100 (worst pain imaginable).

Results: The authors studied 164 children, with 84 patients in the ketorolac group. The groups had similar demographic data. In-hospital analgesic requirements and pain scores were almost identical in both groups. Pain at home was significantly less in the ketorolac group, with visual linear analog pain scale scores of 10 (0-80) compared with 20 (0-80) (median [range]) for ketorolac versus caudal (P = 0.002 by the Mann-Whitney U test). The ketorolac group also had a lower incidence of vomiting, ambulated more rapidly, and micturated earlier (P < 0.05).     

Quality of recovery in children: sevoflurane versus propofol

BACKGROUND: Sevoflurane, with its low pungency and low blood and tissue solubility, is an attractive anaesthetic in paediatric outpatient surgery. Propofol-anaesthesia is recognised for its rapid and clear-headed emergence. This study was designed to compare emergence and recovery characteristics of sevoflurane and propofol anaesthesia for tonsillectomy in children. METHODS: Children aged 3-10 years, undergoing elective tonsillectomy, were randomly assigned to receive propofol (n=25, induction with 3 mg x kg(-1), maintenance with 100-250 microg x kg(-1) min(-1)) or sevoflurane anaesthesia (n=25, induction 7 vol.%, maintenance 2-3 vol.%). Tracheal intubation was performed with alfentanil 20 microg x kg(-1) and atracurium 0.5 mg x kg(-1). Ventilation was controlled to maintain normocapnia and all patients received N2O/O2 (60:40 vol.%) for induction and maintenance of anaesthesia. At the end of surgery infiltration of the operative sites with bupivacaine 2 mg x kg(-1) was provided for postoperative analgesia. Emergence, recovery, discharge times, and incidence of side effects were compared between the two groups. RESULTS: Time to extubation (14 vs 15 min), time to response to simple verbal command (21 vs 21 min) and time to discharge from the recovery room (45 vs 50 min) were similar in the sevoflurane and propofol groups, respectively. There was a significantly greater incidence of postoperative agitation in the sevoflurane group (46%) compared with the propofol group (9%) (P=0.008). This did not, however, delay discharge from the recovery room. The incidence of nausea and vomiting was not significantly different (8% vs 0%; P=0.49). CONCLUSION: In children, recovery from anaesthesia with sevoflurane results in a higher incidence of agitation compared with propofol.     

A-line autoregression index monitoring to titrate inhalational anaesthesia: effects on sevoflurane consumption, emergence time and memory

BACKGROUND: A-line autoregression index (AAI) is a parameter derived from auditory evoked potentials proposed as depth of anaesthesia monitor. We evaluated the effects of AAI guidance on sevoflurane consumption, emergence time, explicit and implicit memory. METHODS: One hundred patients submitted to major abdominal surgery were randomized into two groups. In group A (n = 50), sevoflurane was titrated according to AAI (target = 20 +/- 5), in group B (n = 50) according to clinical signs. Anaesthesia was induced with fentanyl, propofol, atracurium and maintained with sevoflurane. The mean value of sevoflurane consumption (g/min) and emergence time has been assessed in both groups. After emergence, A test of explicit memory was administered. We assessed implicit memory using a category generation test. RESULTS: In group A, mean sevoflurane consumption was significantly (P = 0.0001) reduced by 20.4% and mean emergence time was significantly (P = 0.00012) shorter by 2 min with respect to group B. No patients experienced explicit memory while the difference between the two groups in implicit memory results was not significant (P = 0107). CONCLUSIONS: AAI titration of anaesthesia allows a significant reduction in sevoflurane consumption and emergence time without significant effects on the incidence of explicit and implicit memory. Nevertheless the relationship between AAI and memory requires studies in larger groups of patients.     

Preoperative anxiety and emergence delirium and postoperative maladaptive behaviors

Based on previous studies, we hypothesized that the clinical phenomena of preoperative anxiety, emergence delirium, and postoperative maladaptive behavioral changes were closely related. We examined this issue using data obtained by our laboratory over the past 6 years. Only children who underwent surgery and general anesthesia using sevoflurane/O(2)/N(2)O and who did not receive midazolam were recruited. Children's anxiety was assessed preoperatively with the modified Yale Preoperative Anxiety Scale (mYPAS), emergence delirium was assessed in the postanesthesia care unit, and behavioral changes were assessed with the Post Hospital Behavior Questionnaire (PHBQ) on postoperative days 1, 2, 3, 7, and 14. Regression analysis showed that the odds of having marked symptoms of emergence delirium increased by 10% for each increment of 10 points in the child's state anxiety score (mYPAS). The odds ratio of having new-onset postoperative maladaptive behavior changes was 1.43 for children with marked emergence status as compared with children with no symptoms of emergence delirium. A 10-point increase in state anxiety scores led to a 12.5% increase in the odds that the child would have a new-onset maladaptive behavioral change after the surgery. This finding is highly significant to practicing clinicians, who can now predict the development of adverse postoperative phenomena, such as emergence delirium and postoperative behavioral changes, based on levels of preoperative anxiety.     

Emergence agitation in paediatric patients after sevoflurane anaesthesia and no surgery: a comparison with halothane

This study was designed to compare the emergence characteristics of sevoflurane with halothane anaesthesia in paediatric patients having no surgical intervention. We randomized 32 ASA I or II paediatric outpatients scheduled for magnetic resonance imaging scans to receive either halothane or sevoflurane anaesthesia. The primary outcome measure was the percentage of patients with emergence agitation, as defined by two different criteria. Time to discharge from the postanaesthesia care unit (PACU) and the secondary recovery unit (SRU) were compared. Sevoflurane patients had a greater incidence of emergence delirium when a high threshold for agitation was defined (33% vs. 0%, P = 0.010) and a lower threshold for agitation was applied (80% vs. 12%, P<0.0001). Discharge times from the PACU and the SRU were not different. We conclude that there is an increased incidence of emergence agitation with sevoflurane anaesthesia compared to halothane independent of any painful stimulus.     

Single-dose dexmedetomidine reduces agitation and provides smooth extubation after pediatric adenotonsillectomy

BACKGROUND: Dexmedetomidine has shown sedative, analgesic, and anxiolytic effects after intravenous (IV) administration. Sevoflurane is associated with a high incidence of emergence agitation in preschool children. In this placebo-controlled study, we examined the effect of single dose dexmedetomidine on emergence agitation in children undergoing adenotonsillectomy. METHODS: In a double-blinded trial, 60 children (age 3-7 years) were randomly assigned to receive dexmedetomidine 0.5 microg.kg(-1) IV or placebo, 5 min before the end of surgery. All patients received a standardized anesthetic regimen. For induction and maintenance of anesthesia we used sevoflurane. After surgery, the incidence and severity of agitation was measured 2 h postoperatively. The incidence of untoward airway events after extubation, such as breath holding, severe coughing, or straining were recorded. After surgery, the children's behavior and pain were assessed with a 5-point scale. RESULTS: The agitation and pain scores in the dexmedetomidine group were better than those in the placebo group (P < 0.05). The incidence of severe agitation (a score of 4 or more), and severe pain (a score of 3 or more) were significantly less in the dexmedetomidine group (P < 0.05). The number of severe coughs per patient in the dexmedetomidine group was significantly decreased compared with the control group (P < 0.05). Postoperative vomiting was similar in both groups. Times to emergence and extubation were significantly longer in the dexmedetomidine group (P < 0.05). CONCLUSIONS: We conclude that 0.5 microg.kg(-1) dexmedetomidine reduces agitation after sevoflurane anesthesia in children undergoing adenotonsillectomy.     

右美托咪定术前滴鼻对全麻患儿术后行为改变的影响

目的观察右美托咪定术前滴鼻对全麻患儿术后行为改变的影响。方法择期在全麻下行疝囊高位结扎术的患儿60例,男46例,女14例,年龄2~5岁,体重10~30kg,ASAⅠ或Ⅱ级。采用随机数字表法,将其均分为三组:对照组(C组)、咪达唑仑组(M组)和右美托咪定组(D组)。麻醉诱导前30min,C组生理盐水0.02ml/kg滴鼻,M组咪达唑仑0.2mg/kg滴鼻,D组右美托咪定2μg/kg滴鼻。记录患儿与父母分离时的镇静评分及七氟醚诱导时的面罩接受程度评分;记录患儿术后恢复时间、术后并发症及镇痛药补救率等情况。分别在术前1d、术后1、7、30d用术后行为量表(PHBQ)对患儿父母进行术前问卷调查及术后电话随访,观察患儿术后行为改变的情况。结果M组和D组与父母分离时的镇静评分及七氟醚诱导时的面罩接受程度评分明显高于C组(P0.05)。D组苏醒期躁动、恶心呕吐及镇痛药补救率明显低于C组和M组(P0.05)。术后1、7d时M组和D组行为改变的发生率明显低于C组(P0.05)。结论右美托咪定术前滴鼻可以降低全麻患儿术后行为改变的发生率。