Feasibility study of cumulative sum (CUSUM) analysis as a competency assessment tool for ultrasound-guided venous access procedures.

PURPOSE: Typically, physician training programs use a self-reported case-log competency assessment that does not measure procedure success or objectively assess competency. Cumulative sum (CUSUM) analysis could provide objective assessments of competency and progress over the training period. Our study objective was to determine the feasibility of CUSUM analysis to assess competency of ultrasound-guided peripheral intravenous (USG-PIV) line placement in pediatric anesthesiology fellows. METHODS: We applied a CUSUM analysis to assess competency in USG-PIV placement in three consecutive pediatric anesthesia fellowship classes. After a didactic and hands-on training session, fellows placed a USG-PIV line and self-reported the outcomes via a web-based application. Fellows were deemed competent if the CUSUM curve crossed two consecutive boundary lines from above. RESULTS: Twenty-nine fellows reported 1,388 USG-PIV attempts, with 74% success. Most fellows (26/29; 90%) achieved competency by the end of the fellowship. Two fellows identified in the mid-year CUSUM as not progressing towards competency achieved competency after targeted interventions. Fellows achieving competency (11/29 vs 25/29; odds ratio, 15; 95% confidence interval [CI], 1.98 to 113.56; P = 0.01) and attempts needed to achieve competency (19 vs 11; mean difference, 8.5; 95% CI, 3.3 to 13.7; P = 0.002) were significantly lower in younger patients and significantly higher in older patients. CONCLUSION: Our study showed that CUSUM can be used to assess competence in USG-PIV procedures performed by pediatric anesthesia fellows and to identify learners not progressing toward competency in procedural skills. Ultrasound-guided venous access required more attempts to achieve competency in younger patients.

RéSUMé: OBJECTIF: En règle générale, les programmes de formation des médecins se fondent sur une évaluation autodéclarée des compétences dans un registre des cas qui ne mesure pas la réussite de l'intervention et n'évalue pas objectivement la compétence. L'analyse du cumul des écarts (CUSUM - pour CUmulative SUM) pourrait fournir des évaluations objectives des compétences et des progrès au cours de la période de formation. L'objectif de notre étude était de déterminer la faisabilité d'une analyse CUSUM pour évaluer la compétence pour le positionnement du cathéter intraveineux périphérique échoguidé (CIP-écho) des fellows en anesthésiologie pédiatrique. MéTHODE: Nous avons appliqué une analyse CUSUM pour évaluer la compétence pour le positionnement du CIP-écho de trois classes consécutives de fellows en anesthésie pédiatrique. Après une séance de formation didactique et pratique, les fellows ont placé un cathéter CIP-écho et ont déclaré eux-même les résultats via une application Web. Les fellows étaient jugés compétents si la courbe CUSUM franchissait deux lignes de démarcation consécutives à partir du haut. RéSULTATS: Vingt-neuf fellows ont rapporté 1388 tentatives de CIP-écho, avec un taux de réussite de 74 %. La plupart des fellows (26/29; 90 %) ont acquis la compétence à la fin de leur fellowship. Deux fellows identifiés dans l'analyse CUSUM de mi-année comme ne progressant pas vers la compétence sont parvenus à l'acquérir après des interventions ciblées. Les fellows acquérant cette compétence (11/29 vs 25/29; rapport de cotes, 15; intervalle de confiance [IC] à 95 %, 1,98 à 113,56; P = 0,01) et les tentatives nécessaires pour acquérir la compétence (19 vs 11; différence moyenne, 8,5; IC 95 %, 3,3 à 13,7; P = 0,002) étaient significativement plus basses avec des patients plus jeunes et significativement plus élevés chez les patients plus âgés. CONCLUSION: Notre étude a montré qu'une analyse CUSUM pouvait être utilisée pour évaluer la compétence pour les procédures de CIP-écho réalisées par des fellows en anesthésie pédiatrique et pour identifier les apprenants qui ne progressent pas vers la compétence en habiletés opératoires. L'accès veineux échoguidé a nécessité davantage de tentatives pour atteindre la compétence chez les patients plus jeunes.

Comparison of Intranasal Dexmedetomidine and Oral Pentobarbital Sedation for Transthoracic Echocardiography in Infants and Toddlers: A Prospective, Randomized, Double-Blind Trial.

BACKGROUND: Acquisition of transthoracic echocardiographic (TTEcho) images in children often requires sedation. The optimal sedative for TTEcho has not been determined. Children with congenital heart disease are repeatedly exposed to sedatives and anesthetics that may affect brain development. Dexmedetomidine, which in animals alters brain structure to a lesser degree, may offer advantages in this vulnerable population. METHODS: A prospective, randomized, double-blind trial enrolled 280 children 3-24 months of age undergoing outpatient TTEcho, comparing 2.5 µg·kg intranasal dexmedetomidine to 5 mg·kg oral pentobarbital. Rescue sedation, for both groups, was intranasal dexmedetomidine 1 µg·kg. The primary outcome was adequate sedation within 30 minutes without rescue sedation, assessed by blinded personnel. Secondary outcomes included number of sonographer pauses, image quality in relation to motion artifacts, and parental satisfaction. RESULTS: Success rates with a single dose were not different between sedation techniques; 85% in the pentobarbital group and 84% in the dexmedetomidine group (P = .8697). Median onset of adequate sedation was marginally faster with pentobarbital (16.5 [interquartile range, 13-21] vs 18 [16-23] minutes for dexmedetomidine [P = .0095]). Time from drug administration to discharge was not different (P = .8238) at 70.5 (64-83) minutes with pentobarbital and 70 (63-82) minutes with dexmedetomidine. Ninety-five percent of sedation failures with pentobarbital and 100% of dexmedetomidine failures had successful rescue sedation with intranasal dexmedetomidine. CONCLUSIONS: Intranasal dexmedetomidine was comparable to oral pentobarbital sedation for TTEcho sedation in infants and did not increase the risk of clinically important adverse events. Intranasal dexmedetomidine appears to be an effective "rescue" sedative for both failed pentobarbital and dexmedetomidine sedation. Dexmedetomidine could be a safer option for repeated sedation in children, but further studies are needed to assess long-term consequence of repeated sedation in this high-risk population.

Comparison of different anesthesia techniques during esophagogastroduedenoscopy in children: a randomized trial.

BACKGROUND: Esophagogastroduedenoscopy (EGD) in children is usually performed under general anesthesia. Anesthetic goals include minimization of airway complications while maximizing operating room (OR) efficiency. Currently, there is no consensus on which anesthetic technique best meets these goals. We performed a prospective randomized study comparing three different anesthetic techniques. AIMS: To evaluate the incidence of respiratory complications (primary aim) and institutional efficiency (secondary aim) among three different anesthetic techniques in children undergoing EGD. METHODS: Subjects received a standardized inhalation induction of anesthesia followed by randomization to one of the three groups: Group intubated, sevoflurane (IS), Group intubated, propofol (IP), and Group native airway, nonintubated, propofol (NA). Respiratory complications included minor desaturation (SpO2 between 94% and 85%), severe desaturation (SpO2 < 85%), apnea, airway obstruction/laryngospasm, aspiration, and/or inadequate anesthesia during the endoscopy. Evaluation of institutional efficiency was determined by examining the time spent during the different phases of care (anesthesia preparation, procedure, OR stay, recovery, and total perioperative care). RESULTS: One hundred and seventy-nine children aged 1-12 years (median 7 years; 4.0, 10.0) were enrolled (Group IS N = 60, Group IP N = 59, Group NA N = 61). The incidence of respiratory complications was higher in the Group NA (0.459) vs Group IS (0.033) or Group IP (0.086) (P < 0.0001). The most commonly observed complications were desaturation, inadequate anesthesia, and apnea. There were no differences in institutional efficiency among the three groups. CONCLUSION: Respiratory complications were more common in Group NA. The use of native airway with propofol maintenance during EGD does not offer advantages with respect to respiratory complications or institutional efficiency.

To Pretreat or Not to Pretreat: Prophylactic Anticholinergic Administration Before Dexmedetomidine in Pediatric Imaging.

BACKGROUND: Dexmedetomidine (Dex) appears to be very effective as a sole sedative for pediatric imaging when used at high doses, but at an increased risk of transient hypertension, hypotension, and bradycardia. There are no clinical evidence/guidelines to guide anesthesia providers as to whether patients should be pretreated with an anticholinergic. The aim of this study was to demonstrate the changes in hemodynamic parameters after Dex sedation attributed to receiving or not receiving an anticholinergic pretreatment and compare for any differences or similarities. A subgroups analysis was performed in children with Down syndrome (DS). METHODS: In this retrospective descriptive study, we reviewed the records of 163 children receiving Dex anesthesia during MRI studies. Data analyzed included demographics, history of DS, and hemodynamics (heart rate [HR], systolic blood pressure [SBP], and diastolic blood pressure [DBP]) following Dex loading and infusion and the administration of an anticholinergic (atropine or glycopyrrolate). RESULTS: The mean age was 94.5 months, and 52 (32%) patients had DS. The generalized linear mixed-effects regression model showed a significant reduction in HR and SBP in all patients when no anticholinergic was administered compared with when it was administered. There was no significant change with DBP. During the scan period, the HR of the no-anticholinergic group decreased 26.6%, whereas that of the anticholinergic group decreased by only 16.7% from baseline (P < 0.01). The maximal SBP increased by a significantly greater percentage, compared with baseline, in the anticholinergic group in comparison with the no-anticholinergic group (20.2% vs 10.4%, respectively; P = 0.02). In the DS group, the difference in the maximal SBP change during the scan period was exaggerated, with a percentage increase that was 36 times larger in the anticholinergic group compared with the no-anticholinergic group (22% vs 0.6%, respectively; P< 0.01). CONCLUSIONS: Administration of a prophylactic anticholinergic with Dex shows no advantage other than a transient clinically insignificant increase in HR and SBP, and it may precipitate transient exaggerated SBP in more patients compared with not using a prophylactic anticholinergic.

Trending and accuracy of noninvasive hemoglobin monitoring in pediatric perioperative patients.

BACKGROUND: Rainbow Pulse CO-Oximetry technology (Masimo Corporation, Irvine, CA) provides continuous and noninvasive measurement of arterial hemoglobin concentration (SpHb). We assessed the trending and accuracy of SpHb by this innovative monitoring compared with Hb concentration obtained with conventional laboratory techniques (Hb) in children undergoing surgical procedures with potential for substantial blood loss. METHODS: Hb concentrations were recorded from Pulse CO-Oximetry and a conventional hematology analyzer. Regression analysis and 4-quadrant plot were used to evaluate the trending for changes in SpHb and Hb measurements (ΔSpHb and ΔHb). Bias, precision, and limits of agreement of SpHb and of in vivo adjusted SpHb (SpHb - first bias to HB) compared with Hb were calculated. RESULTS: One hundred fifty-eight SpHb-Hb data pairs and 105 delta pairs (ΔSpHb and ΔHb) from 46 patients aged 2 months to 17 years with Hb ranging from 16.7 to 7.9 g/dL were collected. To evaluate trending, the delta pairs (ΔSpHb and ΔHb) were plotted, which revealed a positive correlation (ΔSpHb = 0.022 + 0.76ΔHb) with correlation coefficient r = 0.76, 95% CI [confidence interval] = 0.57-0.86. The bias and precision of SpHb to Hb and in vivo adjusted SpHb were 0.4 ± 1.3 g/dL and 0.1 ± 1.2 g/dL, respectively; the limits of agreement were -2.0 to 3.2 g/dL before in vivo adjustment and -2.4 to 2.2 g/dL after in vivo adjustment (P value = 0.04). The mean percent bias (from the reference Hb concentration) decreased from 4.1% ± 11.9% to 0.7% ± 11.3% (P value = 0.01). No drift in bias over time was observed during the study procedure. Of patient demographic and physiological factors tested for correlation with the SpHb, only perfusion index at sensor site showed a weak correlation. CONCLUSIONS: The accuracy of SpHb in children with normal Hb and mild anemia is similar to that previously reported in adults and is independent of patient demographic and physiological states except for a weak correlation with perfusion index. The trending of SpHb and Hb in children with normal Hb and mild anemia showed a positive correlation. Further studies are necessary in children with moderate and severe anemia.

Effect of increasing depth of dexmedetomidine and propofol anesthesia on upper airway morphology in children and adolescents with obstructive sleep apnea.

STUDY OBJECTIVE: To examine the dose-response effects of dexmedetomidine (DEX) and propofol (PROP) on airway morphology in children and adolescents with a history of obstructive sleep apnea (OSA). DESIGN: Prospective, single-blinded, controlled comparative study. SETTING: University-affiliated teaching hospital. PATIENTS: 60 patients with a history of OSA who presented for a magnetic resonance imaging (MRI) sleep study. INTERVENTIONS: Patients were randomized to two equal groups (DEX or PROP). Magnetic resonance images of the airway were obtained during low (1 µg/kg/hr) and high (3 µg/kg/hr) doses of DEX, or low (100 µg/kg/m) and high (200 µg/kg/m) doses of PROP, based on group assignment. MEASUREMENTS: The airway anteroposterior (AP) diameter, transverse diameter, and sectional areas were measured at the level of the nasopharyngeal airway and retroglossal airway. The influence of the two drugs and OSA severity, as determined by polysomnography, on airway dimensions was examined using mixed-effects analysis of covariance models. MAIN RESULTS: Upper airway morphology was completed in 45 patients. Most airway measurements showed statistically nonsignificant associations with increasing doses of PROP and DEX. As the dosage increased, average airway dimensions were typically unchanged or slightly increased with DEX compared with airway dimensions that were unchanged or slightly decreased with PROP. An airway intervention was required in three children (11%) in the DEX group and 7 children (23%) in the PROP group (P = NS). CONCLUSIONS: Both agents provided an acceptable level of anesthesia for MRI sleep studies in patients with OSA, with statistically nonsignificant changes in airway dimensions.

Insufflation vs intubation during esophagogastroduodenoscopy in children.

OBJECTIVES: We compared adverse airway events during esophagogastroduodenoscopy (EGD) in children managed with insufflation vs intubation. BACKGROUND: Optimum airway management during EGD in children remains undecided. METHODS/MATERIALS: Following IRB approval and written informed parental consent, children between 1 and 12 years of age presenting for EGD were randomized to airway management with insufflation (Group I), intubation/awake extubation (Group A), or intubation/deep extubation (Group D). All subjects received a standardized anesthetic with sevoflurane in oxygen. Using uniform definitions, airway adverse events during and after EGD recovery were recorded. Categorical data were analysed with Chi-square contingency tables or Fisher's exact test as appropriate. RESULTS: Analyzable data were available for 415 subjects (Group I: 209; Group A: 101; Group D: 105). Desaturation, laryngospasm, any airway adverse event, and multiple airway adverse events during EGD were significantly more common in subjects in Group I compared to those in Groups A and D. Complaints of sore throat, hoarseness, stridor, and/or dysphagia were more common in subjects in Groups A and D. Analysis of confounders suggested that younger age, obesity, and midazolam premedication were independent predictors of airway adverse events during EGD. CONCLUSIONS: Insufflation during EGD was associated with a higher incidence of airway adverse events, including desaturation and laryngospasm; intubation during EGD was associated with more frequent complaints related to sore throat. As our results show that insufflation during EGD offers no advantage in terms of operational efficiency and is associated with more airway adverse events, we recommend endotracheal intubation during EGD, especially in patients who are younger, obese, or have received midazolam premedication.

Effect of increasing depth of dexmedetomidine anesthesia on upper airway morphology in children.

OBJECTIVE: This prospective study examines the dose-response effects of dexmedetomidine on upper airway morphology in children with no obstructive sleep apnea (OSA). AIM: To determine the effect of increasing doses of dexmedetomidine on static and dynamic magnetic resonance (MR) images of the upper airway in spontaneously breathing children with no OSA. BACKGROUND: General anesthetics and sedatives attenuate upper airway muscle activity, rendering the airway vulnerable to obstruction. Dose-response effects of dexmedetomidine on upper airway of children are not known. We prospectively examined the dose-response effects of dexmedetomidine on upper airway morphology in children. METHODS/MATERIALS: Increasing doses of dexmedetomidine was administered to 23 children scheduled for MR imaging of the brain while breathing spontaneously via the native airway. Static axial and dynamic sagittal midline MR ciné images of the upper airway were obtained during low (1 mcg.kg(-1).h(-1)) and high (3 mcg.kg(-1).h(-1)) doses of dexmedetomidine. The airway anteroposterior diameter, transverse diameter, and cross-sectional areas were measured manually by two independent observers. Static airway measurements were taken at the level of the nasopharyngeal airway (sagittal images) and retroglossal airway (RGA) (sagittal and axial images). Dynamic change in cross-sectional area of airway between inspiration and expiration was considered a measure of airway collapsibility. RESULTS: Static axial measurements of RGA did not change with increasing dose of dexmedetomidine. Most sagittal airway dimensions demonstrated clinically modest, although statistically significant, reductions with high dose compared to low dose dexmedetomidine. Although, the dynamic changes in nasopharyngeal and retroglossal area with respiration were marginally greater for high dose than for low dose dexmedetomidine, no subject exhibited any clinical evidence of airway obstruction. CONCLUSION: Upper airway changes associated with increasing doses of dexmedetomidine in children with no OSA are small in magnitude and do not appear to be associated with clinical signs of airway obstruction. Even though these changes are small, all precautions to manage airway obstruction should be taken when dexmedetomidine is used for sedation.

Real-time assessment of perioperative behaviors in children and parents: development and validation of the perioperative adult child behavioral interaction scale.

BACKGROUND: Behavior in response to distressful events during outpatient pediatric surgery can contribute to postoperative maladaptive behaviors, such as temper tantrums, nightmares, bed-wetting, and attention seeking. Currently available perioperative behavioral assessment tools have limited utility in guiding interventions to ameliorate maladaptive behaviors because they cannot be used in real time, are only intended to be used during 1 phase of the experience (e.g., perioperative), or provide only a static assessment of the child (e.g., level of anxiety). A simple, reliable, real-time tool is needed to appropriately identify children and parents whose behaviors in response to distressful events at any point in the perioperative continuum could benefit from timely behavioral intervention. Our specific aims were to (1) refine the Perioperative Adult Child Behavioral Interaction Scale (PACBIS) to improve its reliability in identifying perioperative behaviors and (2) validate the refined PACBIS against several established instruments. METHODS: The PACBIS was used to assess the perioperative behaviors of 89 children aged 3 to 12 years presenting for adenotonsillectomy and their parents. Assessments using the PACBIS were made during perioperative events likely to prove distressing to children and/or parents (perioperative measurement of blood pressure, induction of anesthesia, and removal of the IV catheter before discharge). Static measurements of perioperative anxiety and behavioral compliance during anesthetic induction were made using the modified Yale Preoperative Anxiety Scale and the Induction Compliance Checklist (ICC). Each event was videotaped for later scoring using the Child-Adult Medical Procedure Interaction Scale-Short Form (CAMPIS-SF) and Observational Scale of Behavioral Distress (OSBD). Interrater reliability using linear weighted kappa (kappa(w)) and multiple validations using Spearman correlation coefficients were analyzed. RESULTS: The PACBIS demonstrated good to excellent interrater reliability, with kappa(w) ranging from 0.62 to 0.94. The Child Coping and Child Distress subscores of the PACBIS demonstrated strong concurrent correlations with the modified Yale Preoperative Anxiety Scale, ICC, CAMPIS-SF, and OSBD. The Parent Positive subscore of the PACBIS correlated strongly with the CAMPIS-SF and OSBD, whereas the Parent Negative subscore showed significant correlation with the ICC. The PACBIS has strong construct and predictive validities. CONCLUSIONS: The PACBIS is a simple, easy to use, real-time instrument to evaluate perioperative behaviors of both children and parents. It has good to excellent interrater reliability and strong concurrent validity against currently accepted scales. The PACBIS offers a means to identify maladaptive child or parental behaviors in real time, making it possible to intervene to modify such behaviors in a timely fashion.

A comparison of dexmedetomidine with propofol for magnetic resonance imaging sleep studies in children.

BACKGROUND: Magnetic resonance imaging (MRI) sleep studies can be used to guide management of children with obstructive sleep apnea (OSA) refractory to conservative therapy. Because children with OSA are sensitive to the respiratory-depressant effects of sedatives and anesthetics, provision of anesthesia for imaging studies in this patient population can be challenging. Dexmedetomidine has been shown to have pharmacological properties simulating natural sleep with minimal respiratory depression. We hypothesized that, compared with propofol, dexmedetomidine would have less effect on upper airway tone and airway collapsibility, provide more favorable conditions during dynamic MRI airway imaging in children with OSA, have fewer scan interruptions, and require less aggressive airway interventions. METHODS: In this retrospective descriptive study, we reviewed the records of 52 children receiving dexmedetomidine and 30 children receiving propofol for anesthesia during MRI sleep studies between July 2006 and March 2008. Documentation of the severity of OSA by overnight polysomnography was available for 67 of the 82 subjects, who were analyzed separately. Data analyzed included demographics, severity of OSA, comorbidities, hemodynamic changes, use of artificial airways, additional airway maneuvers, and successful completion of the MRI scan. RESULTS: Demographics, OSA severity by polysomnography, anesthetic induction, and baseline hemodynamics were comparable in both groups. An interpretable MRI sleep study was obtained for 98% of children in the dexmedetomidine group and 100% in the propofol group. Of 82 children, MRI sleep studies were successfully completed without the use of artificial airways in 46 children (88.5%) in the dexmedetomidine group versus 21 children (70%) in the propofol group (P = 0.03). An artificial airway was required to complete the study in five children (12%) in the dexmedetomidine group versus nine children (35%) in the propofol group (P = 0.06). Additional airway maneuvers (chin lift and shoulder roll) were required to complete the study in one child (2%) in the dexmedetomidine group and three children (10%) in the propofol group (P = 0.14). Children in the dexmedetomidine group experienced reductions in heart rate, whereas those in the propofol group experienced reductions in arterial blood pressure; these reductions were statistically, but not clinically, significant. CONCLUSIONS: Dexmedetomidine provided an acceptable level of anesthesia for MRI sleep studies in children with OSA, producing a high yield of interpretable studies of the patient's native airway. The need for artificial airway support during the MRI sleep study was significantly less with dexmedetomidine than with propofol. Dexmedetomidine may be the preferred drug for anesthesia during MRI sleep studies in children with a history of severe OSA and may offer benefits to children with sleep-disordered breathing requiring anesthesia or anesthesia for other diagnostic imaging studies.

Real-time assessment of perioperative behaviors and prediction of perioperative outcomes.

BACKGROUND AND AIMS: New onset maladaptive behaviors, such as temper tantrums, nightmares, bed-wetting, attention-seeking, and fear of being alone are common in children after outpatient surgery. Preoperative anxiety, fear and distress behaviors of children predict postoperative maladaptive behaviors as well as emergence delirium. Parental anxiety has also been found to influence children's preoperative anxiety. Currently, there is no real-time and feasible tool to effectively measure perioperative behaviors of children and parents. We developed a simple and real-time scale, the Perioperative Adult Child Behavioral Interaction Scale (PACBIS) to assess perioperative child and parent behaviors that might predict postoperative problematic behavior and emergence excitement. METHODS: We used the PACBIS to evaluate perioperative behaviors during anesthetic induction and recovery in a sample of 89 children undergoing tonsillectomies and adenoidectomies, and their parents. Preoperative anxiety with the modified Yale Preoperative Anxiety Scale, compliance with induction of anesthesia with Induction Compliance Checklist, and incidence of emergence excitement were also recorded. RESULTS: The PACBIS demonstrated good concurrent validity with modified Yale Preoperative Anxiety Scale and Induction Compliance Checklist and predicted postanesthetic emergence excitement. DISCUSSION: The PACBIS is the first real-time scoring instrument that evaluates children's and parents' perioperative behavior. The specific behaviors identified by the PACBIS might provide targets for interventions to improve perioperative experiences and postoperative outcomes.

Preparation of the Dräger Fabius anesthesia machine for the malignant-hyperthermia susceptible patient.

BACKGROUND: Anesthesia machines must be flushed of halogenated anesthetics before use in patients susceptible to malignant hyperthermia. We studied the kinetics of sevoflurane clearance in the Dräger Fabius anesthesia machine and compared them to a conventional anesthesia machine (Dräger Narkomed GS). METHODS: Before each trial, the anesthesia machine was contaminated for 2 h with 3% sevoflurane and then prepared by changing the CO(2) absorbent, removing the vaporizer(s), and mounting a clean circuit and artificial lung. The basic flush procedure consisted of oxygen 10 L/min with the ventilator set to a tidal volume of 600 mL at a rate of 10/min. Residual sevoflurane in the inspiratory limb of the circuit was measured using an ambient air analyzer capable of measuring sevoflurane to < 1 ppm. Results were analyzed using log-linear regression of residual concentration as a function of time. This model was used to estimate the time required to achieve a desired residual anesthetic concentration. RESULTS: Times to achieve 10 and 5 ppm in the Dräger Narkomed GS were 11 and 18 min, respectively. For the Dräger Fabius anesthesia machine, times to 10 and 5 ppm were 75 and 104 min, respectively. Several maneuvers to accelerate clearance of residual sevoflurane from the Dräger Fabius resulted in only modest reductions in these times (10 and 5 ppm times 40-50 min and 60-80 min, respectively). Insertion of an activated charcoal filter (QED, Anecare Laboratories, Salt Lake City, UT) into the inspiratory limb of the Dräger Fabius circuit reduced the residual anesthetic concentration to <5 ppm within 10 min; this concentration was maintained for > 6 h despite a fresh gas flow of only 2 L/min after the first 15 min. DISCUSSION: Preparation of the Dräger Fabius anesthesia machine using conventional flushing techniques required almost 10 times as long as an older, conventional anesthesia machine. If a prolonged flush is impractical or impossible, we describe a procedure using an activated charcoal filter inserted on the inspiratory limb of the breathing circuit which can effectively scrub residual sevoflurane to a concentration < 5 ppm within 10 min. This procedure includes an initial 5 min flush without the activated charcoal filter followed by a 5 min flush with the charcoal filter, after which the machine is ready for use in the malignant hyperthermia-susceptible patient. The charcoal filter must remain on the machine for the remainder of the anesthetic, and the fresh gas flow should be maintained > or = 10 L/min for the first 5 min, and > or = 2 L/min thereafter.

Factors predictive of poor behavioral compliance during inhaled induction in children.

BACKGROUND: Preoperative identification of children at risk of emotional distress and poor behavioral compliance during inhaled induction of anesthesia allows targeted interventions to reduce distress, thereby enhancing the quality of the anesthetic experience. We sought to identify patient, procedural, and health care system factors predictive of poor behavioral compliance during induction. METHODS: We studied 861 developmentally appropriate children ages 1-13 yr, The American Society of Anesthesiologists physical status I to III, presenting for inhaled induction of anesthesia. All inductions were performed in an induction room with parent(s) present. Behavioral compliance was assessed using the Induction Compliance Checklist (ICC), an observational scale consisting of 10 behaviors scored as the number of behaviors observed during induction; ICC > or =4 was considered poor behavioral compliance. A multivariable ordinal logistic regression model for behavioral compliance was generated and the performance of the multivariable model was evaluated by the c statistic. RESULTS: Twenty-one percent of children exhibited poor behavioral compliance on induction. Factors increasing the odds of poor behavioral compliance were younger age (< 4 yr, P < 0.0001), shorter preoperative preparation time (P = 0.004), and high anxiety levels in the preoperative clinic (modified-Yale preoperative anxiety scale > 40; P = 0.016). Previous anesthesia experience increased the odds in school-age children (P = 0.046); this effect was ameliorated in children attending the preoperative tour (P = 0.018). The model using these factors demonstrated moderate discrimination between children with poor compliance and those with perfect compliance (ICC = 0) (c statistic = 0.75). CONCLUSIONS: Factors predictive of poor behavioral compliance were age, previous anesthesia, preoperative tour attendance, preoperative preparation time and anxiety levels in the preoperative clinic. These factors, bundled into a predictive algorithm, may help identify children who could benefit from behavioral or pharmacological interventions and avoid use of interventions to those at low risk.

Anesthetic implications of undiagnosed late onset central hypoventilation syndrome in a child: from elective tonsillectomy to tracheostomy.

Late onset central hypoventilation syndrome is a neurological disorder that can present with postoperative respiratory complications and delayed emergence in children after anesthesia. We present a child who had unanticipated respiratory complications following an elective tonsillectomy who eventually required a tracheostomy and long-term ventilatory support.

A factorial study of ondansetron, metoclopramide, and dexamethasone for emesis prophylaxis after adenotonsillectomy in children.

BACKGROUND: We conducted a factorial study of emesis prophylaxis with ondansetron (OND), metoclopramide (MET), and dexamethasone (DEX). METHODS: After informed parental consent, 240 children having adenotonsillectomy were randomized to one of 15 combinations of OND (0-60 microg.kg(-1)), MET (0-400 microg.kg(-1)), and/or DEX (0-500 microg.kg(-1)). Using multivariable logistic regression, models were generated for the probability of emesis before discharge, after discharge and overall for 24 h. RESULTS: Odds of emesis increased by a factor of three to four for children older than 7 years. Before discharge, odds of emesis decreased by factors of 0.29 for each 15 microg.kg(-1) of OND and 0.37 for each 100 microg.kg(-1) of MET. After discharge, odds of emesis decreased by a factor of 0.67 for each 125 microg.kg(-1) of DEX and increased by a factor of 3.5 for emesis before discharge. Over 24 h, odds of emesis decreased with OND, MET, and DEX (ORs as above). A negative interaction between OND and MET was seen before discharge and over 24 h, reducing the efficacy of their combination. CONCLUSIONS: We present novel study design and methods of analysis which are uniquely suited to studies of multiple interventions. Factorial design was a powerful tool, allowing simultaneous determination of dose-response relationships for three drugs and identifying a previously unreported negative interaction between OND and MET.