Anesthesiologist- and System-Related Risk Factors for Risk-Adjusted Pediatric Anesthesia-Related Cardiac Arrest.

BACKGROUND: Pediatric anesthesia-related cardiac arrest (ARCA) is an uncommon but potentially preventable adverse event. Infants and children with more severe underlying disease are at highest risk. We aimed to identify system- and anesthesiologist-related risk factors for ARCA. METHODS: We analyzed a prospectively collected patient cohort data set of anesthetics administered from 2000 to 2011 to children at a large tertiary pediatric hospital. Pre-procedure systemic disease level was characterized by ASA physical status (ASA-PS). Two reviewers independently reviewed cardiac arrests and categorized their anesthesia relatedness. Factors associated with ARCA in the univariate analyses were identified for reevaluation after adjustment for patient age and ASA-PS. RESULTS: Cardiac arrest occurred in 142 of 276,209 anesthetics (incidence 5.1/10,000 anesthetics); 72 (2.6/10,000 anesthetics) were classified as anesthesia-related. In the univariate analyses, risk of ARCA was much higher in cardiac patients and for anesthesiologists with lower annual caseload and/or fewer annual days delivering anesthetics (all P < 0.001). Anesthesiologists with the highest academic rank and years of experience also had higher odds of ARCA (P = 0.02). After risk adjustment for ASA-PS ≥ III and age ≤ 6 months, however, the association with lower annual days delivering anesthetics remained (P = 0.03), but the other factors were no longer significant. CONCLUSIONS: Case-mix explained most associations between higher risk of pediatric ARCA and anesthesiologist-related variables at our institution, but the association with fewer annual days delivering anesthetics remained. Our findings highlight the need for rigorous adjustment for patient risk factors in anesthesia patient safety studies.

Pediatric sedation in a community hospital-based outpatient MRI center.

OBJECTIVE: Although the demand for pediatric MRI is increasing, it is uncommon to find sedation being offered at community hospital-based outpatient centers. We present our safety, efficacy, and outcome data at a community hospital-based outpatient imaging center. MATERIALS AND METHODS: I.v. dexmedetomidine sedation was administered as a bolus of 3 µg/kg and maintained with a continuous infusion of 1 µg/kg/hr until imaging was complete. The dexmedetomidine bolus could be repeated up to two times, if needed. Quality assurance data were reviewed. RESULTS: From April 2009 to July 2010, 279 children (mean age, 4.2 years; age range, 0.2-17.2 years) were sedated. All received a first bolus, 46 required a second dose, and two received a third. The average time to achieve sedation was 7.8 minutes (SD, ± 3.8 minutes). Total duration of imaging (82% brain MRI) averaged 38.1 minutes (range, 8.0-126.0 minutes). On average, discharge criteria were met within 21.3 minutes of arrival in recovery room (± 17.8 minutes). The heart rate and blood pressure deviated from baseline by more than 20% in 5% and 33% of the patients, respectively. No pharmacologic therapy was administered to treat the hemodynamic variability. There were no adverse respiratory events. All imaging studies were successfully completed. CONCLUSION: Dexmedetomidine offers an option for pediatric sedation for MRI at community hospital-based outpatient settings. It preserves respiration but elicits deviations in blood pressure and heart rate that have not required pharmacologic intervention. Dexmedetomidine offers a safe, effective, and efficient agent for sedation for children undergoing MRI in an outpatient setting.

A Pilot Study of Ketamine versus Midazolam/Fentanyl Sedation in Children Undergoing GI Endoscopy.

Background. Ketamine sedation has been found superior by physician report to traditional sedation regimens for pediatric endoscopy. Goal. To objectively compare sedation with ketamine versus midazolam/fentanyl for children undergoing gastrointestinal endoscopy. Study. Patients received one of two regimens and were independently monitored using a standardized rating scale. Results. There were 2 episodes of laryngospasm during ketamine sedation. Univariate analyses showed patients sedated with ketamine (n = 17) moved more (median 25% of procedure time versus 8%, P = .03) and required similar low levels of restraint (0.83% versus 0.25%, P = .4) as patients sedated with midazolam/fentanyl (n = 20). Age-adjusted analyses suggested that patients sedated with ketamine were comparably more quiet (P = .002). Conclusions. A pilot trial of ketamine at our institution was associated with episodes of laryngospasm. In addition, children sedated with ketamine moved and required restraint similarly to patients sedated with midazolam/fentanyl. Physician perceptions may be affected by the fact that children who received ketamine were less likely to vocalize distress.

Incidence and predictors of hypertension during high-dose dexmedetomidine sedation for pediatric MRI.

UNLABELLED: This study reviewed the hypertensive response of a large population of children to high-dose dexmedetomidine sedation with the aim of determining the incidence and predictors of hypertension. BACKGROUND: When dexmedetomidine is used to provide sedation for children, fluctuations in blood pressure have been described in case reports. We report the incidence and predictors of hypertension in a large series of children who received dexmedetomidine. METHODS/MATERIALS: At our institution, a computerized database holds patient demographics, sedation outcomes, adverse events, and hemodynamic data for all children who receive dexmedetomidine sedation for radiological imaging studies. After Institutional Review Board approval, this database was reviewed. RESULTS: Three thousand five hundred twenty-two (3522) children received dexmedetomidine sedation between May 1, 2007 and December 31, 2008 for magnetic resonance imaging studies. Median age was 3.6 years (interquartile range: 1.8-5.9). A total of 172 patients (4.9%) developed hypertension, with a higher incidence in the younger age group (0-3 years) when compared to the older age groups (3-18 years) (P < 0.05). Multivariable logistic regression modeling confirmed that younger age (Wald test = 43.5 of 5 degrees of freedom, P < 0.001) and more than one bolus (Wald test = 22.7, P < 0.001) were highly significant predictors of the occurrence of hypertension. CONCLUSION: When high-dose dexmedetomidine is used for pediatric sedation for MR imaging, the incidence of hypertension is low. Hypertension is most likely to occur in children <1 year of age during the continuous infusion, after they have received more than one bolus of dexmedetomidine.

An exaggerated hypertensive response to glycopyrrolate therapy for bradycardia associated with high-dose dexmedetomidine.

At our institution, high-dose i.v. dexmedetomidine is used to provide sedation for pediatric patients undergoing nonpainful radiological imaging studies. Some of these patients exhibit marked bradycardia (more than 20% deviation from the lowest age-adjusted normal values) while maintaining an arterial blood pressure within an acceptable normal range. We report on three cases wherein treatment of dexmedetomidine-induced bradycardia with i.v. glycopyrrolate (5.0 microg/kg) not only resulting in resolution of bradycardia but also resulting in an exaggerated increase of arterial blood pressure.

Is propofol a safe alternative to pentobarbital for sedation during pediatric diagnostic CT?

PURPOSE: To prospectively compare the incidence of adverse respiratory events, the need for airway interventions, and the recovery time after propofol sedation with similar data from a retrospective review of data obtained in patients who underwent pentobarbital sedation. MATERIALS AND METHODS: This HIPAA-compliant study was conducted with institutional review board approval and parental informed consent. The hospital sedation committee approved a 2-month pilot program of propofol sedation as a potential alternative to pentobarbital sedation. Parents were given the choice of having their child sedated with intravenously administered propofol or pentobarbital. Fifty-two patients (18 female, 34 male; mean age, 2.9 years +/- 2.4 [standard deviation]) received propofol. An equal number of patients (21 female, 31 male; mean age, 2.5 years +/- 1.7) who previously received pentobarbital were included. The sample sizes provided 80% power to detect differences in airway manipulations, adverse respiratory events, and recovery time between the groups by using the Fisher exact test and the Student t test. A two-tailed P value of less than .05 indicated a significant difference. RESULTS: Patients sedated with propofol underwent significantly more airway manipulations to relieve obstruction than did patients sedated with pentobarbital (23% vs 0%, P < .001). More adverse respiratory events occurred in the propofol group than in the pentobarbital group (12% vs 0%, P = .03). Patients in the propofol group had a faster recovery profile than did patients in the pentobarbital group (34 minutes +/- 17 vs 100 minutes +/- 30, P < .001). CONCLUSION: Propofol is associated with a significantly greater incidence of adverse respiratory events than is pentobarbital.

High dose dexmedetomidine as the sole sedative for pediatric MRI.

OBJECTIVE: This large-scale retrospective review evaluates the sedation profile of dexmedetomidine. AIM: To determine the hemodynamic responses, efficacy and adverse events associated with the use of high dose dexmedetomidine as the sole sedative for magnetic resonance imaging (MRI) studies. BACKGROUND: Dexmedetomidine has been used at our institution since 2005 to provide sedation for pediatric radiological imaging studies. Over time, an effective protocol utilizing high dose dexmedetomidine as the sole sedative agent has evolved. METHODS/MATERIALS: As part of the ongoing Quality Assurance process, data on all sedations are reviewed monthly and protocols modified as needed. Data were analyzed from all 747 consecutive patients who received dexmedetomidine for MRI sedation from April 2005 to April 2007. RESULTS: Since 2005, the 10-min loading dose of our dexmedetomidine protocol increased from 2 to 3 microg.kg(-1), and the infusion rate increased from 1 to 1.5 to 2 microg.kg(-1).h(-1). The current sedation protocol progressively increased the rate of successful sedation (able to complete the imaging study) when using dexmedetomidine alone from 91.8% to 97.6% (P = 0.009), reducing the requirement for adjuvant pentobarbital in the event of sedation failure with dexmedetomidine alone and decreased the mean recovery time by 10 min (P < 0.001). Although dexmedetomidine sedation was associated with a 16% incidence of bradycardia, all concomitant mean arterial blood pressures were within 20% of age-adjusted normal range and oxygen saturations were 95% or higher. CONCLUSION: Dexmedetomidine in high doses provides adequate sedation for pediatric MRI studies. While use of high dose dexmedetomidine is associated with decreases in heart rate and blood pressure outside the established 'awake' norms, this deviation is generally within 20% of norms, and is not associated with adverse sequelae. Dexmedetomidine is useful as the sole sedative for pediatric MRI.

Hemodynamic effects of dexmedetomidine sedation for CT imaging studies.

BACKGROUND: Dexmedetomidine sedation for radiological imaging studies is a relatively recent application for this drug. Previous studies have demonstrated some haemodynamic effects of dexmedetomidine, however, the effects remain poorly described in children. The aim of this study was to better define the effect of age on heart rate (HR) and blood pressure changes in children sedated for CT imaging with dexmedetomidine. METHODS/MATERIALS: At our institution dexmedetomidine is given for sedation for CT imaging as a bolus of 2 mcg.kg(-1) over 10 min followed by an infusion of 1 mcg.kg(-1).h(-1) with a second bolus if required. Detailed quality assurance data sheets document patient demographics, sedation outcomes, adverse events, and hemodynamic data are recorded for each patient. RESULTS: A total of 250 patients (range 0.1-10.6 years) received dexmedetomidine. ANOVA revealed strong evidence for changes in HR and mean arterial blood pressure during bolus and infusion relative to presedation values (P < 0.001). These changes were apparent in each age group and similar between groups. During the first bolus and during infusion, 82% and 93% of patients respectively were within the age-based normal range for HR. For mean arterial blood pressure, 70% of patients were within the normal range during first bolus and 78% during infusion. CONCLUSION: In the pediatric population studied, intravenous dexmedetomidine sedation was associated with modest fluctuations in HR and blood pressure. Hemodynamic changes were independent of age, required no pharmacologic interventions and did not result in any adverse events. By anticipating these possible hemodynamic effects and avoiding dexmedetomidine in those patients who may not tolerate such fluctuations in HR and blood pressure, dexmedetomidine is an appropriate sedative for children undergoing CT imaging.

Efficiency of propofol versus midazolam and fentanyl sedation at a pediatric teaching hospital: a prospective study.

BACKGROUND: Many pediatric endoscopists are adopting propofol in their practices, with the expectation that propofol will increase their overall efficiency. OBJECTIVE AND SETTING: To compare the efficiency of propofol versus midazolam and fentanyl by measuring elapsed times between initial intravenous administration and patient discharge at a pediatric teaching hospital. DESIGN: Endoscopy times were prospectively collected for consecutive patients who were undergoing either anesthesiologist-administered propofol or endoscopist-administered midazolam and fentanyl. The effect of the type of sedation on these times was assessed by using multiple linear regression by adjusting for other candidate predictors, including concomitant use of other sedatives, endotracheal intubation by anesthesiologists, and the presence of fellow trainees. MAIN OUTCOME MEASUREMENTS: Time to onset of sedation (time sedation started to scope in), procedure time (endoscope in to endoscope out), discharge time (endoscope out to hospital discharge), and total time (sedation started to hospital discharge). RESULTS: The times for 134 children (mean age 12 +/- 5 years) to receive propofol sedation were compared with those of 195 children (13 +/- 5 years) who received midazolam and fentanyl. Midazolam and fentanyl cases disproportionately included EGDs (P < .001) and patients who were classified as American Society of Anesthesiologists I (P < .03). Patients who received propofol had shorter times until sedated, similar procedure times, longer discharge times, and comparable total times. Multivariate analyses confirmed that fellow participation prolonged the procedure times (P < .0001), and endotracheal intubation prolonged propofol times (P <. 01), but adjusting for these did not change the comparison results. CONCLUSIONS: Anesthesiologist-administered propofol sedation in a pediatric teaching endoscopy unit may not lead to faster hospital times when compared with endoscopist-administered midazolam and fentanyl. These results are not explained by controlling for patient characteristics, the presence of a trainee, the sedative doses, or endotracheal intubation for airway management.

Dexmedetomidine for pediatric sedation for computed tomography imaging studies.

Dexmedetomidine is a sedative with limited experience in the pediatric population. This is the first study that prospectively evaluates the sedation profile of a dexmedetomidine pilot program for pediatric sedation for radiological imaging studies. In March 2005, our hospital sedation committee approved the replacement of IV pentobarbital with dexmedetomidine as the standard of care for CT imaging. Detailed Quality Assurance (QA) data sheets collect relevant information on each patient, which is then logged into a computerized sedation database. After IRB approval, all QA data was accessed. Sixty-two patients with a mean age of 2.8 years (SD = 1.8, range 0.5-9.7) received IV (IV) dexmedetomidine administered as a 2 mcg/kg loading dose over 10 minutes, followed by repeat boluses of 2 mcg/kg over 10 minutes until target of Ramsay Sedation Score 4 (RSS) achieved. Patients were then maintained on 1 mcg/kg/hr infusion until imaging is completed. Repeated-measures ANOVA indicated that compared to pre-sedation values, the heart rate and mean arterial blood pressure decreased an average of 15% during bolus, infusion and recovery (P < 0.01). No significant changes were observed in respiratory rate or end-tidal CO2. Mean recovery time was 32 +/- 18 minutes. Based on our pilot results, dexmedetomidine may provide a reliable and effective method of providing sedation.