Recruiting

Dexmedetomidine & Propofol

Sponsor:

Boston Children's Hospital

Code:

NCT07369128

Conditions

MRI Sedation

Pediatric Sedation

Propofol Dosage

Emergence Delirium, Anesthesia

Recovery Time

Eligibility Criteria

Sex: All

Age: 1 - 12

Healthy Volunteers: Not accepted

Interventions

Dexmedetomidine (IV) 0.5 mcg/kg

Propofol (IV) 2-4 mg/kg

Dexmedetomidine (IV) 1 mcg/kg

Propofol (IV) 1-2 mg/kg

Propofol (IV) Infusion 250 mcg/kg/min

Study Details

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.

Conditions

MRI Sedation

Pediatric Sedation

Propofol Dosage

Emergence Delirium, Anesthesia

Recovery Time

Study ID

NCT07369128

Start date

Jun, 2026

Status verified date

Jan, 2026

Completion date

Mar, 2028

Anticipated

Primary completion date

Dec, 2027

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 1 - 12

Healthy Volunteers: Not accepted

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

Study Design

Enrollment

105 participants

Anticipated

Allocation

Randomized

Intervention Model

Parallel Assignment

Primary purpose

Other

Interventions and Outcome Measures

Arms

active comparator: Propofol Only (P)

1 mg/kg (max 25 kg) of IV lidocaine (standard of care) will be given. 2-4 mg/kg titrated bolus of propofol will be administered, which can be repeated 2x until a Ramsay Sedation Score of 5-6 is achieved. After that, 250 mcg/kg/min infusion of propofol will be initiated and can be titrated up to a maximum of 300 mcg/kg/min to maintain a Ramsay Sedation Score of 5-6. If not sedated after 5 more minutes, record a technique failure and continue sedation at anesthesiologist's discretion. Per standard of care, the propofol infusion may be decreased if the blood pressure decreases by more than 30% from lowest expected norms or if there is any indication of possible airway obstruction.

active comparator: Dexmedetomidine (high)-Propofol (DHP)

1 mcg/kg dexmedetomidine (DEX) bolus over 5-10 minutes will be delivered by fractionated doses or infusion. After the DEX bolus is complete, 1 mg/kg (max 25 mg) of IV lidocaine will be administered followed by a dose of 2-3 mg/kg titrated bolus of propofol (P), which can be repeated 2x until a Ramsay Sedation Score of 5-6 is achieved. After this, 150 mcg/kg/min infusion of P will be initiated. If the Ramsay Sedation score of 5-6 is not achieved within 2 minutes, 1-2 mg/kg bolus of P may be administered and P infusion will be increased to 200 mcg/kg/min. The P infusion can be titrated up to a maximum of 300 mcg/kg/min if needed to maintain a Ramsay Sedation Score of 5-6. If not sedated after 5 more minutes, record a technique failure and continue sedation at anesthesiologist's discretion. Per standard of care, the propofol infusion may be decreased if the blood pressure decreases by more than 30% from lowest expected norms or if there is any indication of possible airway obstruction.

active comparator: Dexmedetomidine (low)-Propofol (DLP)

0.5 mcg/kg dexmedetomidine (DEX) bolus over 5-10 minutes will be delivered by fractionated doses or infusion. After the DEX bolus is complete, 1 mg/kg (max 25 mg) of IV lidocaine will be administered followed by a dose of 2-3 mg/kg titrated bolus of propofol (P), which can be repeated 2x until a Ramsay Sedation Score of 5-6 is achieved. After this, 150 mcg/kg/min infusion of P will be initiated. If the Ramsay Sedation score of 5-6 is not achieved within 2 minutes, 1-2 mg/kg bolus of P may be administered and P infusion will be increased to 200 mcg/kg/min. The P infusion can be titrated up to a maximum of 300 mcg/kg/min if needed to maintain a Ramsay Sedation Score of 5-6. If not sedated after 5 more minutes, record a technique failure and continue sedation at anesthesiologist's discretion. Per standard of care, the propofol infusion may be decreased if the blood pressure decreases by more than 30% from lowest expected norms or if there is any indication of possible airway obstruction.

Interventions

Dexmedetomidine (IV) 0.5 mcg/kg

If patient is randomized to the DLP arm, patient will receive an IV bolus of 0.5 mcg/kg dexmedetomidine over 5 minutes.

Propofol (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.

Dexmedetomidine (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.

Propofol (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.

Propofol (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.

Propofol (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.

Primary outcome measure

  • Total Propofol (mcg/kg/min) consumption [ Time Frame: Up to 120 minutes or from induction of anesthesia/sedation to end of MRI scan ]

Central Contacts and Locations

Central contacts

Samuel Kim, BS

617-919-3692samuel.kim@childrens.harvard.edu

Rachel Bernier, MPH

857-218-5348rachel.bernier@childrens.harvard.edu

Locations

Boston Children's Hospital

Recruiting

Boston, Massachusetts, United States, 02115

Contacts

Joseph Cravero, MD

joseph.cravero@childrens.harvard.edu

More Information

Sponsor

Boston Children's Hospital

Last update posted

May 29, 2026

Last verified

Jan, 2026

Keywords

  • pediatrics
  • sedation
  • dexmedetomidine
  • propofol
  • MRI

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-10. This information was provided to ClinicalTrials.gov by Boston Children's Hospital on 2026-05-29.