Propofol-Only Versus Dexmedetomidine-Propofol in Children Undergoing Magnetic Resonance Imaging

Official title

A Randomized, Dose-Ranging Trial of Propofol-Only and Dexmedetomidine-Propofol in Children Undergoing Magnetic Resonance Imaging

Overview

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

• Drug 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.
• Drug 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.
• Drug 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.
• Drug 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.
• Drug 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.
• Drug 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 measures

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

Secondary outcome measures (7)

• Peak Pediatric Anesthesia Emergence Delirium (PAED) Score [Time frame: Up to 180 minutes or duration of PACU stay]
• Incidence of Adverse Events [Time frame: Up to 240 minutes or from induction of anesthesia/sedation to immediately during recovery]
• Incidences of Patient Movements/MRI Interruptions [Time frame: Up to 90 minutes or duration of MRI scan]
• Incidence of Technique Failure [Time frame: Up to 120 minutes or from induction of anesthesia/sedation to end of MRI scan]
• Case Duration [Time frame: Up to 90 minutes or duration of MRI scan]
• Post Anesthesia Care Unit (PACU) Duration [Time frame: Up to 180 minutes or duration of PACU stay]
• Ramsay Sedation Score [Time frame: 10 minutes or from anesthesia induction to MRI scan start]

Eligibility criteria

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

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: No

Study design

Allocation

Randomized

Model

Parallel assignment

Masking

Double blind

Primary purpose

Other

Study locations

United States · 1 center

• Boston Children's Hospital — Boston

Publications

• Nagoshi M, Reddy S, Bell M, Cresencia A, Margolis R, Wetzel R, Ross P. Low-dose dexmedetomidine as an adjuvant to propofol infusion for children in MRI: A double-cohort study. Paediatr Anaesth. 2018 Jul;28(7):639-646. doi: 10.1111/pan.13400. Epub 2018 Jun 7. PMID 29882298
• Ramaprasannakumar SK, Bhadrinarayan V, Venkataramaiah S. The Effectiveness of Three Regimens of Sedation for Children Undergoing Magnetic Resonance Imaging: A Clinical Study. Anesth Essays Res. 2022 Jul-Sep;16(3):345-352. doi: 10.4103/aer.aer_45_22. Epub 2022 Dec 9. PMID 36620110
• Boriosi JP, Eickhoff JC, Klein KB, Hollman GA. A retrospective comparison of propofol alone to propofol in combination with dexmedetomidine for pediatric 3T MRI sedation. Paediatr Anaesth. 2017 Jan;27(1):52-59. doi: 10.1111/pan.13041. Epub 2016 Oct 25. PMID 27779360
• Vinson AE, Peyton J, Kordun A, Staffa SJ, Cravero J. Trends in Pediatric MRI sedation/anesthesia at a tertiary medical center over time. Paediatr Anaesth. 2021 Sep;31(9):953-961. doi: 10.1111/pan.14225. Epub 2021 Jun 22. PMID 34036674
• Kim SY, Booth JM, Staffa SJ, Kordun A, Yu J, Cravero JP. A dose-ranging pilot trial of dexmedetomidine-propofol in children undergoing magnetic resonance imaging. J Anesth. 2025 Dec;39(6):989-994. doi: 10.1007/s00540-025-03511-z. Epub 2025 May 11. PMID 40349256
• Rappaport BA, Suresh S, Hertz S, Evers AS, Orser BA. Anesthetic neurotoxicity--clinical implications of animal models. N Engl J Med. 2015 Feb 26;372(9):796-7. doi: 10.1056/NEJMp1414786. PMID 25714157
• Mallory MD, Travers C, Cravero JP, Kamat PP, Tsze D, Hertzog JH. Pediatric Sedation/Anesthesia for MRI: Results From the Pediatric Sedation Research Consortium. J Magn Reson Imaging. 2023 Apr;57(4):1106-1113. doi: 10.1002/jmri.28392. Epub 2022 Aug 12. PMID 36173243

Identifiers

NCT: NCT07369128 · IRB-P00052391

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗