Comparison of Outcomes During MRI Sedation With Midazolam-dexmedetomidine Versus Ketamine-dexmedetomidine

Not Applicable

Terminated

Brief Summary: This study will compare 2 different sedation drugs (Ketamine and Midazolam) when they are used with another sedating medicine called Dexmedetomidine for MRI sedation. This study hopes to measure the impact each drug has on what happens during and after MRI sedation with Dexmedetomidine

Detailed Description: The will be a randomized, double-blind, prospective study. All patients referred to UCSS for brain MRI and for whom dexmedetomidine would otherwise be the sedation regimen of choice will be eligible for enrollment. The investigators propose to limit the study to patients undergoing only brain MRI as these studies are of a predictable length (25-30 minutes); therefore the sedation regimen can be more easily standardized. Parents of eligible patients would be approached prior to or during the pre-sedation assessment and told about the study and, if they agree to enroll, informed consent would be obtained. Assent will be obtained from children 7 years of age and greater, if they are otherwise developmentally capable of giving assent. The goal is to enroll 50 subjects (25 per treatment group) which would be sufficient to detect a 25% or greater difference in the mean maximal heart rate or blood pressure decrease from baseline between the 2 groups.

Following consent, subjects would be randomized to be sedated with either midazolam-dexmedetomidine or ketamine-dexmedetomidine and, upon achieving an appropriate depth of sedation, undergo their MRI. Monitoring during the MRI and subsequent recovery would occur in compliance with the current Norton Children's Hospital Sedation policy. Recovery-related behavior would be assessed using the Pediatric Anesthesia Emergence Delirium Scale.

Recruitment & Eligibility

Inclusion Criteria

Exclusion Criteria

Previous adverse reaction to dexmedetomidine or clonidine
Current use of clonidine as a routine medication
Concurrent use of a heart-rate decreasing medication (digoxin, propranolol)
Contraindication to ketamine use
- Intracranial hypertension or traumatic brain injury
- Intraocular hypertension of eye trauma
- Pulmonary hypertension requiring medical management
Planned additional procedure during the sedation encounter (non-brain MRI, lumbar puncture, EEG etc)

Arm && Interventions

Group	Intervention	Description
Dexmedetomidine and Midazolam	Dexmedetomidine	Subjects will already be getting Dexmedetomidine and Midazolam for their routine care.
Dexmedetomidine and Midazolam	Midazolam	Subjects will already be getting Dexmedetomidine and Midazolam for their routine care.
Dexmedetomidine and Ketamine	Ketamine	Subjects will already be getting Dexmedetomidine and Ketamine for their routine care.
Dexmedetomidine and Ketamine	Dexmedetomidine	Subjects will already be getting Dexmedetomidine and Ketamine for their routine care.

Primary Outcome Measures

Name	Time	Method
The Number of Participants With Hypotension and/or Bradycardia During Sedation and Recovery (Generally 2-3 Hours)	a total of 2-3 hours during sedation and recovery.	number of participants developing hypotension and or bradycardia

Secondary Outcome Measures

Name	Time	Method
Percent Change in Heart Rate From Baseline	during sedation and recovery (generally 2-3 hours)	Change in heart rate from baseline.
The Number of Participants With Adverse Recovery-related Behaviors During Sedation Recovery	Recovery-related behaviors will be specifically measured using the "Pediatric Anesthesia Emergence Delirium (PAED)" scale every 5 minutes from procedure completion until sedation recovery is complete (usually less than 2 hrs)	This study will compare the number of participants with adverse recovery-related behaviors, based on the PAED scores, between the 2 treatment arms.
Percent Change in Blood Pressure From Baseline	during sedation and recovery (generally 2-3 hours)	Change in blood pressure from baseline.