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Study Objective: To assess the effect of two different remifentanil infusion doses on hemodynamic stability and recovery characteristics in children undergoing tracheobronchial foreign body removal during rigid bronchoscopy. Design: Prospective, randomized, clinical comparison study. Setting: Operating room of a university hospital. Patients: 70 ASA physical status 1 and 2 children, aged 3-12 years, presenting for tracheobronchial foreign body removal during rigid bronchoscopy. Interventions: Children were divided equally into two groups to receive either a 0.1 μg/kg/min (Group R1) or 0.2 μg/kg/min (Group R2) remifentanil infusion. Ten minutes after the remifentanil infusion, 3 mg/kg of propofol and 0.02 mg/kg of atropine were given. Anesthesia was maintained with 0.1 μg/kg/min of remifentanil and 100-250 μg/kg/min of propofol in Group R1 and 0.2 μg/kg/min of remifentanil and 100-250 μg/kg/min of propofol in Group R2. After baseline measurements were recorded, 0.2 mg/kg of mivacurium was given intravenously. Ventilation was maintained with 100% O2 via a "T" piece connected to the side arm of the bronchoscope. Measurements: Heart rate (HR), systolic (SBP), diastolic (DBP) and mean arterial pressures (MAP), and O2 saturation (SpO2) were recorded before (baseline) and after induction, and 1, 3, 5, 10, 15, 20, 25, and 30 minutes after insertion of the rigid bronchoscope into the trachea. Emergence characteristics and complications were noted. Statistical analysis was performed using independent samples t-test, repeated measures, and chi-square test as appropriate. Main Results: Groups were similar in demographics and duration of bronchoscopy and anesthesia (P N 0.05). In Group R1, HR, SBP, DBP, and MAP increased one minute after insertion of the bronchoscope in Group R1 (P b 0.01). Propofol consumption was significantly higher in Group R1 (63.6 ± 30.1 mg) than Group R2 (39.8 ± 26.6 mg; P b 0.01). Time to spontaneous eye opening was 8.6 ± 1.3 minutes in Group R1 and 6.3 ± 1.1 minutes in Group R2 (P b 0.05). The time to recovery to an Aldrete score of 9 was greater in Group R1 (19.8± 3.0 min) than Group R2 (16.1±3.0 min; P b 0.01). Conclusion: A remifentanil 0.2 μg/kg/min infusion with propofol provides hemodynamic stability and early recovery in children undergoing foreign body removal during rigid bronchoscopy. [ABSTRACT FROM AUTHOR]

Aim: To evaluate the impact of bispectral index (BIS) monitoring on the consumption of propofol and recovery from anesthesia compared to the standard clinical practice in children. Background: Titrating propofol administration using BIS reduces its requirement and shortens the recovery from anesthesia in adults. However, there is still mixed evidence for utility of anesthesia depth monitors in reducing anesthesia requirement in children. Methods/Materials: A prospective randomized study was conducted in 50 ASA I children of 2–12 years, randomly assigned into standard practice (SP) or BIS group. After induction with propofol, anesthesia was maintained with 150 μg·kg−1·min−1 propofol infusion. The propofol infusion rate was altered by 20 μg·kg−1·min−1 to maintain the systolic blood pressure within 20% of the baseline (SP group) or BIS value between 45 and 60 (BIS group). The rate of propofol infusion was reduced by 50% about 15 min before the end of surgery. The amount of propofol used and the times from stopping the propofol infusion to eye opening, extubation, response to commands and attaining Steward score of 6 were recorded. Results: There was no evidence of a difference in the mean propofol consumption in the two groups (BIS 232.6 ± 136.7 mg, SP 250.8 ± 118.2 mg). The intraoperative hemodynamics and BIS values were similar in the two groups. There was no evidence for a difference between groups in the mean times from termination of anesthetic to eye opening, extubation, response to commands and to achieve a Steward Recovery score of 6. Conclusions: Our study showed no benefit of BIS-guided propofol administration on anesthetic consumption or recovery compared to standard anesthetic practice. [ABSTRACT FROM AUTHOR]

Introduction: Age influences the potency of anesthetic agents, but there is little information on how age influences MAC-awake. MAC-awake may be an important aspect of anesthesia potency for the prevention of awareness during anesthesia. The aim of this study was to measure MAC-awake in a range of ages in children. Methods: After institutional ethics approval and informed parental consent 60 children were enrolled; 20 in each of three age groups (2 to <5, 5 to <8 and 8–12 years). Children were excluded if they had opioids, sedative premedication or a procedure likely to cause any residual discomfort. All children had sevoflurane anesthesia. At the end of the procedure the sevoflurane was decreased to the target concentration. Once the target endtidal concentration was achieved it was maintained for 10 min before a standard stimulus was applied and an observer determined if the child was awake. The Dixon up–down method was used to determine progression of subsequent concentrations and MAC-awake (ED50) for the three age groups were obtained using the probit model. Results: This study found evidence for a difference in ED50 between age groups ( P = 0.008). The MAC-awake was highest in the youngest group (0.66%) and similar in the older groups (0.45% and 0.43%). Conclusion: Although MAC-awake changes with age, in the ages where awareness has been reported, MAC-awake was found to be relatively low, and therefore it seems unlikely that age-specific changes to MAC-awake are a cause for awareness in children aged 5–12 years. [ABSTRACT FROM AUTHOR]

Background: The characteristics of the electroencephalogram (EEG) during anesthesia in children are poorly described. An understanding of the EEG during anesthesia may help explain and predict the performance of EEG-derived depth of anesthesia monitors in children. This study aims to describe the association between age and some basic characteristics of the EEG during nonstandardized anesthesia in children and infants. Methods: Sixty-four children aged 9 days to 12 years were enrolled in this observational physiological study. Anesthesia was given at the discretion of the anesthetist. EEG was recorded from after induction to emergence using a BRM2 brain monitor ’’BrainZ Instruments, Auckland, New Zealand‘‘ in parietal and frontal montages. For comparison, 90% spectral edge frequency (SEF-90) and power were determined at three points (equilibrium during anesthesia, when the volatile agent was discontinued and at emergence), and children were divided into three age groups (0–6 months, 6–24 months and 2–12 years). Results: Fifty-seven children had artifact-free EEG data. From equilibrium to emergence the mean forehead power decreased substantially in children aged 2–12 years (3171–153 μV2, P < 0.001) and 6–24 months (756–140 μV2, P < 0.001) but no difference was found in infants aged 0–6 months (93–63 μV2, P = 0.4). From equilibrium to emergence mean forehead spectral edge frequency increased in children aged 2–12 years (10.8–13.7 Hz, P = 0.01) but no change was found in children aged 6–24 months (12.7–12.7 Hz, P = 0.9) or 0–6 months (9.45–7.26 Hz, P = 0.08). Throughout emergence, infants demonstrated a discontinuous EEG pattern with intermittent bursts separated with low amplitude. Conclusions: During anesthesia, the EEG in infants is fundamentally different from the EEG in older children. This study supports the need for specific infant-derived algorithms if EEG-derived anesthesia depth monitors are to be used in infants. [ABSTRACT FROM AUTHOR]

Background: Level of anesthesia may be predicted with the auditory evoked potential or with passive processed electroencephalogram (EEG) parameters. Some previous reports suggest the passive EEG does not reliably predict level of anesthesia in infants. The AAI-1.6 is a relatively new index derived from the AEP/2 monitor. It combines auditory evoked potentials and passive EEG parameters into a single index. This study aimed to assess the AAI-1.6 as a predictor of level of anesthesia in infants and children. Methods: Four infants aged less than 1 year, and five older children aged between 2 and 11 years were enrolled. They all had uniform sevoflurane anesthesia for cardiac catheterization. The AAI-1.6 and bispectral index (BIS) were recorded after achieving equilibrium at 1.5%, 2% and 2.5% sevoflurane, and immediately prior to awakening. The prediction coefficient (Pk) for BIS and AAI-1.6 was calculated and compared within each age group. Results: The Pk for the AAI-1.6 was low in both 0–1 and 2–11 years age groups. In the 2–12 years group, the Pk for BIS was significantly higher than the Pk for the AAI-1.6 (Pk for BIS: 0.89, Pk for AAI-1.6: 0.53, P < 0.01). In contrast in the 0–1 year age group there was no evidence for a difference between the Pk for BIS and the Pk for the AAI-1.6 (Pk for BIS: 0.74, Pk for AAI-1.6: 0.53, P = 0.25). Conclusions: This preliminary study suggests AAI-1.6 is a poor predictor of sevoflurane concentration in infants and children. [ABSTRACT FROM AUTHOR]