John W. Berkenbosch

Sedation during mechanical ventilation in infants and children: dexmedetomidine versus midazolam.

Background: We sought to compare the efficacy of midazolam versus dexmedetomidine for sedation during mechanical ventilation in infants and children. Methods: We performed a prospective, randomized trial in a pediatric intensive care unit in a tertiary care center. Infants and children requiring mechanical ventilation underwent a continuous infusion of either midazolam (starting dose of 0.1 mg/kg/h) or dexmedetomidine (starting dose of either 0.25 or 0.5 μg/kg/h) with intermittent morphine, as needed. The efficacy of sedation was assessed using the Ramsay sedation scale, pediatric intensive care unit sedation score, and the tracheal suctioning score as well as bispectral monitoring. Results: There were 10 patients in each group. Sedation as assessed by the clinical sedation scores and the bispectral index was equivalent in the 3 groups. There were 36 morphine boluses administered to the midazolam group versus 29 and 20 morphine boluses administered respectively to the 0.25 and 0.5 μg/kg/h dexmedetomidine groups (P = 0.02 for midazolam versus 0.5 μg/kg/h dexmedetomidine). Total morphine use (mg/kg/24 h) was 0.74 ± 0.5, 0.55 ± 0.38, and 0.28 ± 0.12 in the midazolam and the two dexmedetomidine groups respectively (P = not significant for midazolam versus 0.25 dexmedetomidine, P = 0.01 for midazolam versus 0.5 dexmedetomidine). In the two dexmedetomidine groups, 5 of 6 patients who at some point had a Ramsay score of 1 were less than 12 months of age while only 1 was more than 12 months of age (P < 0.05). Conclusions: At a dose of 0.25 μg/kg/h, dexmedetomidine was approximately equivalent to midazolam at 0.22 mg/kg/h. At 0.5 μg/kg/h, dexmedetomidine provided more effective sedation as demonstrated by the need for fewer bolus doses of morphine, a decrease in the 24-hour requirements for supplemental morphine, as well as a decrease in the total number of assessment points with a Ramsay score of 1 (inadequate sedation) and the number of patients who had a Ramsay score of 1.

The correlation of the bispectral index monitor with clinical sedation scores during mechanical ventilation in the pediatric intensive care unit.

In patients who are mechanically ventilated in the pediatric intensive care unit (PICU), sedative and/or analgesic medications are routinely provided and titrated to effect based on clinical assessment of the patient. The bispectral index (BIS) monitor uses a modified electroencephalogram to quantify the effects of central nervous system-acting drugs on the level of consciousness. To evaluate the usefulness of the BIS monitor to predict clinical sedation levels in the PICU, we compared BIS values with simultaneously obtained clinical sedation scores in 24 mechanically ventilated pediatric patients aged 5.7 ± 6.1 yr. For each sedation scale used, the BIS value correlated with increasing depth of sedation (P < 0.0001) and was independent of the drug(s) used for sedation. To differentiate adequate from inadequate sedation, a BIS value <70 had a sensitivity of 0.87–0.89 and a positive predictive value of 0.68–0.84. To differentiate adequate from excessive sedation, a BIS value <50 had a sensitivity of 0.67–0.75 and a positive predictive value of 0.07–0.52. We conclude that the BIS monitor may be a useful adjunct for the assessment of sedation in PICU patients.

Initial experience with dexmedetomidine in paediatric-aged patients

We present preliminary clinical experience with the use of dexmedetomidine, an α2 adrenergic agonist, in children. Dexmedetomidine was administered in three clinical scenarios: (i) to provide sedation during mechanical ventilation; (ii) intraoperatively for controlled hypotension during an orthopaedic surgical procedure; and (iii) to provide sedation during an invasive procedure. Preliminary data from studies in the adult population, its physiological effects and potential applications in paediatric anaesthesia and critical care are discussed.

Prospective evaluation of dexmedetomidine for noninvasive procedural sedation in children.

Objective: Children often require sedation for lengthy noninvasive procedures. Conventional agents such as chloral hydrate, benzodiazepines, or barbiturates have been associated with sedation failure, respiratory depression, and paradoxic agitation. Dexmedetomidine is a newer &agr;2-adrenergic receptor agonist with sedative properties and minimal respiratory depression. We hypothesized that it would be an effective agent for these procedures. Design: Prospective case series. Setting: Tertiary care children’s hospital. Patients: Children undergoing noninvasive procedures. Interventions: Children were sedated with dexmedetomidine given as a bolus of 0.5–1.0 &mgr;g/kg over 5–10 mins followed by an infusion of 0.5–1.0 &mgr;g/kg/hr. Vital signs, sedative effectiveness, recovery patterns, and complications were prospectively recorded. Measurements and Main Results: Forty-eight patients, aged 6.9 ± 3.7 yrs, were sedated. Fifteen received dexmedetomidine after failing sedation with chloral hydrate and/or midazolam. Sedation was induced with 0.92 ± 0.36 &mgr;g/kg over 10.3 ± 4.7 mins and maintained with an infusion of 0.69 ± 0.32 &mgr;g/kg/hr. All procedures were completed. Heart rate, blood pressure, and respiratory rate decreased (p < .0001) but remained within normal limits for age. End-tidal CO2 exceeded 50 mm Hg in seven of 404 measurements (1.7%). Mean recovery time was 84 ± 42 mins and was significantly longer in the rescue (117 ± 41 mins) vs. primary (69 ± 34 mins) group (p < .0001). No patient developed agitation during recovery. Conclusions: Dexmedetomidine provided effective sedation in children undergoing noninvasive procedures and represents an alternative sedative choice for this population.

Development of bradycardia during sedation with dexmedetomidine in an infant concurrently receiving digoxin.

Objective To describe the development of bradycardia during sedation with dexmedetomidine in a patient concurrently receiving digoxin. Design Case report. Setting The pediatric intensive care unit of a tertiary care children’s hospital. Patients A 5-wk-old infant with an atrioventricular septal defect requiring sedation during mechanical ventilation for acute respiratory syncytial virus infection. Measurements and Main Results As part of an ongoing evaluation of dexmedetomidine for sedation in the pediatric intensive care unit, the patient received a loading dose (0.5 &mgr;g/kg) followed by an infusion (0.44 &mgr;g·kg−1·hr−1) of dexmedetomidine. Sedation assessments and hemodynamic data were collected at least every 2 hrs. During the loading dose, the patient’s heart rate decreased from 133 beats/min per min to 116 beats/min. During the ensuing 13 hrs, the heart rate continued to decrease into the mid 90s, with additional episodes of bradycardia into the 40s and 50s. Within 1 hr of discontinuation of the dexmedetomidine infusion, the baseline heart rate had recovered, and no further episodes of acute bradycardia were noted. Conclusions This case adds to the limited data regarding dexmedetomidine in pediatric critical care and suggests that caution should be used when considering sedation with dexmedetomidine in patients also receiving digoxin.

Use of a remifentanil–propofol mixture for pediatric flexible fiberoptic bronchoscopy sedation

Background : Flexible fiberoptic bronchoscopy is an important diagnostic tool for pediatric pulmonologists. Because of its favorable respiratory profile, ketamine has become a popular sedative for this procedure, but may be associated with unpleasant emergence reactions in the older child. Remifentanil is a newer, ultra‐short acting opioid that has been shown to provide effective sedation and cough suppression for fiberoptic bronchoscopy when combined with intermittent propofol boluses. However, delivery of these agents as a combined, single infusion has not been described.

Additional experience with dexmedetomidine in pediatric patients.

Purpose This study evaluates the efficacy of dexmedetomidine in clinical scenarios other than sedation during mechanical ventilation. Methods We conducted a retrospective chart review and presentation of case series of children in the pediatric intensive care unit and the postanesthesia care unit who received dexmedetomidine. Results Dexmedetomidine was administered by continuous infusion to three patients and as a single bolus dose (0.5 &mgr;g/kg) to two patients. In the five clinical scenarios, dexmedetomidine provided effective sedation during spontaneous ventilation in two patients, reversed the clinical signs and symptoms of withdrawal from illicit substances in one patient, and was effective in the treatment of postanesthesia emergence delirium and shivering in two additional patients. Conclusion These preliminary data suggest that dexmedetomidine may be an effective agent for sedation in spontaneously breathing patients, in the treatment of drug withdrawal, and in the treatment of two common postanesthesia problems.

Preliminary experience with oral dexmedetomidine for procedural and anesthetic premedication

Background : Oral premedication is often required in children to provide anxiolysis and lessen the psychological impact of hospitalization and/or procedures. We present our experience with dexmedetomidine as an oral premedicant prior to procedural sedation or anesthetic induction.

Rescue sedation with dexmedetomidine for diagnostic imaging: a preliminary report.

Background : Sedation is frequently required during noninvasive radiological imaging in children. Although commonly used agents such as chloral hydrate and midazolam are generally effective, failures may occur. The authors report their experience with dexmedetomidine for rescue sedation during magnetic resonance imaging.

Dexmedetomidine for Procedural Sedation in Children With Autism and Other Behavior Disorders

Dexmedetomidine has been increasingly in use for pediatric noninvasive procedural sedation. This retrospective study examined experience in children with autism and other neurobehavioral disorders, populations often difficult to sedate. Records of children with autism or neurobehavioral disorders sedated with dexmedetomidine at Chris Evert Childrens Hospital and Kosair Childrens Hospital were reviewed. Demographic and sedation-related data were collected, including sedative doses, time to sedation, efficacy, and complications. Comparisons of sedative doses, efficacy between autism and neurobehavioral patients, and analysis of age-related factors were performed. In all, 315 patients were sedated, most commonly for magnetic resonance imaging. Mean induction and total dexmedetomidine doses were 1.4 +/- 0.6 and 2.6 +/- 1.6 microg/kg, respectively, with no differences between autism and neurobehavior patients. Most patients (90%) patients received concomitant midazolam. There was an age-related decrease in dexmedetomidine dose, independent of midazolam use. Seven patients required intervention for hypotension, bradycardia, or both, and only one adverse respiratory event (obstruction requiring nasopharyngeal airway placement) occurred. There were two episodes of overt recovery-related agitation. All but four procedures were successfully completed (4/315, or 98.7%). Dexmedetomidine with or without midazolam was an effective sedative in this population. The regimen appeared to be well tolerated with few adverse events, including recovery-related agitation, and appears to be an attractive option for this population.