Dexmedetomidine, Emergence Delirium, Anesthesia, MRI Sedation, Pediatric Sedation, Propofol Dosage, Recovery Time
Conditions
Keywords
pediatrics, sedation, dexmedetomidine, propofol, MRI
Brief summary
The most common imaging procedure requiring sedation/anesthesia for the pediatric population is magnetic resonance imaging (MRI). However, the optimal anesthetic/sedation plan has not been determined for these procedures. Historically, common medications have included the use of pentobarbital and propofol, but in 2015, publication in the New England Journal of Medicine highlighted the accumulating evidence for the possible neurotoxic effects of these types of anesthetics in animal models and a collection of epidemiologic studies in humans. Although these initial possibilities have since been proven as less of a concern, in the interim, data has shown that alternative sedative agents, such as dexmedetomidine, may not have the same neurotoxic effect and could possibly even provide neuroprotection. Dexmedetomidine also possesses other beneficial traits such as reducing risks of pulmonary atelectasis or upper airway collapse, typically found with the administration of propofol. A concern raised by previous studies has been the possibility that the addition of dexmedetomidine could increase recovery times, leading to disruptions in workflow. Although it has been shown that large doses of dexmedetomidine exposure may lead to longer PACU stays, it is uncertain whether a small dose of dexmedetomidine would have such a significant impact. Based on the investigators' pilot trial6, the investigators found that a bolus of 1 mcg/kg dose of dexmedetomidine with a bolus of titrated propofol of 2-3 mg/kg and an infusion of propofol of 100 mcg/kg/min provided adequate sedation for successful scans, reduced propofol (infusion) exposure by 60%, and did not significantly increase recovery times. Finally, there is a paucity in literature for studies examining a range of doses subsequently; often, a control group is compared to a single, self-selected dose of choice. Here, the investigators hope to provide a range of doses to minimize selection bias in our study design and determine the dose that would provide the optimal sedation for these scans and minimize excess anesthetic exposure.
Interventions
If patient is randomized to the DLP arm, patient will receive an IV bolus of 0.5 mcg/kg dexmedetomidine over 5 minutes.
DRUGPropofol (IV) 2-4 mg/kg
If patient is randomized to the P arm, patient will receive 2-4 mg/kg titrated, IV bolus of propofol until sleep is induced.
DRUGDexmedetomidine (IV) 1 mcg/kg
If patient is randomized to the DHP arm, patient will receive an IV bolus of 1 mcg/kg dexmedetomidine over 5 minutes.
DRUGPropofol (IV) 1-2 mg/kg
If the patient is randomized to the DLP or DHP arm, following the dexmedetomidine bolus, the patient will receive a titrated, IV bolus of 1-2 mg/kg propofol.
DRUGPropofol (IV) Infusion 250 mcg/kg/min
If the patient is randomized to the P arm, following the bolus of propofol, the patient will be started on an IV propofol infusion of 250 mcg/kg/min.
DRUGPropofol (IV) Infusion 150 mcg/kg/min
If the patient is randomized to the DLP or DHP arm, following the titrated propofol bolus, the patient will be started on an IV propofol infusion of 150 mcg/kg/min.
Sponsors
Boston Children's Hospital
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
OTHER
Masking
DOUBLE (Subject, Outcomes Assessor)
Eligibility
Sex/Gender
ALL
Age
1 Years to 12 Years
Healthy volunteers
No
Inclusion criteria
* Patients presenting as outpatients, scheduled to receive an anesthetic for MRI of brain, body (spine, chest, abdomen, and/or pelvis) and/or extremity (arm and/or leg). * Patients must be a candidate for the sedation technique described in this study with a natural airway. This decision will be made by a staff member of the Department of Anesthesiology. * Between 1 and 12 years of age. * ASA status I, II, or III
Exclusion criteria
* Inpatient at BCH * Diagnosis of a difficult airway, severe obstructive sleep apnea that is not compatible with spontaneous ventilation in a supine position, or requires an oral airway. * Congenital heart disease or history of dysrhythmia. * Taking digoxin or beta-blocker * Anxiolytic medication is ordered before the MRI (e.g., midazolam or ketamine). * History or a family (parent or sibling) history of malignant hyperthermia. * Allergy to or has a contraindication to propofol, lidocaine, or dexmedetomidine. * Tracheostomy or other mechanical airway device present * Received within the past 12 hours an oral or intravenous alpha-adrenergic, beta-adrenergic agonist, or antagonist drugs (e.g., clonidine, propranolol, albuterol). * Patient is not scheduled to receive anesthesia-sedation care or is noted to "try-without anesthesia" for the MRI * Patient has significant developmental or psychological delays * Patient scheduled for scan of duration \<30 minutes or \>90 minutes
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Total Propofol (mcg/kg/min) consumption | Up to 120 minutes or from induction of anesthesia/sedation to end of MRI scan | The total amount of propofol (mcg/kg/min) consumed will be measured for the duration of anesthesia time for the P, DLP, and DHP arms. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Peak Pediatric Anesthesia Emergence Delirium (PAED) Score | Up to 180 minutes or duration of PACU stay | The peak (highest) PAED score will be obtained in the post-anesthesia recovery area (PACU). |
| Incidence of Adverse Events | Up to 240 minutes or from induction of anesthesia/sedation to immediately during recovery | Arterial desaturation, airway obstruction, hypotension and bradycardia |
| Incidences of Patient Movements/MRI Interruptions | Up to 90 minutes or duration of MRI scan | If patient moved during their MRI and caused an interruption of the scan. |
| Incidence of Technique Failure | Up to 120 minutes or from induction of anesthesia/sedation to end of MRI scan | Lack of adequate sedation for MRI scan in spite of the sedation as described above (based on anesthesiologist's discretion or PSSS) |
| Case Duration | Up to 90 minutes or duration of MRI scan | Total number of minutes in the MRI scanner |
| Post Anesthesia Care Unit (PACU) Duration | Up to 180 minutes or duration of PACU stay | Total number of minutes in the PACU |
| Ramsay Sedation Score | 10 minutes or from anesthesia induction to MRI scan start | Average Ramsay Sedation Score |
Countries
United States
Contacts
CONTACTSamuel Kim, BS
CONTACTRachel Bernier, MPH
PRINCIPAL_INVESTIGATORJoseph Cravero, MD
Boston Children's Hospital
Outcome results
None listed