Oral Dexmedetomidine in Pediatric MRI

Study Overview
=================
Brief Summary
-----------------
The objective of this preliminary study is to assess the utility of oral dexmedetomidine as the sole sedative agent in pediatric population undergoing MRI

Detailed Description
-----------------
MRI is an important and robust medical imaging technique that has become the cornerstone for radiologic studies. Superior image quality and resolution especially for soft tissue imaging, without the use of ionizing radiation has made MRI one of the most dominant imaging modalities in pediatrics. Despite its many advantages, MRI is not child friendly. Lengthy scan times, the need for lying motionless in a confined space, excessive noise and vibration during image acquisition, are all factors that have made anesthesia an integral part of pediatric MRI. General anesthesia is a state of medically induced unconsciousness, analgesia and muscle relaxation which is required for most invasive medical procedures. Despite being painless, imaging tests such as MRI scans are highly susceptible to motion artifact and require a state of immobility that may not be obtainable in awake uncooperative patients such as pediatrics. While very safe, general anesthesia carries potential risk of serious morbidity and mortality secondary to aspiration during instrumentation of the airway, hypoxia and hypoventilation secondary to laryngospasm/bronchospasm and hemodynamic instability. Therefore, sedation may be an appropriate technique to offer anxiolysis, amnesia and immobility while maintaining airway reflexes with limited impact on ventilation and hemodynamics for non-stimulating procedures such as imaging. Aside from having a more favorable risk/benefit profile compared to general anesthesia when it comes to radiologic studies, sedation is also less costly and burdensome on anesthesia departments and could provide immense cost-saving measures for healthcare institutions at large. While there are many intravenous (IV) sedatives, establishing an awake IV access could be very traumatizing and leave a lasting negative impression of the healthcare environment in a child's mind. Hence, enteral medications may be more acceptable and child friendly. This is especially valuable in patients who require repeated surveillance imaging and who demonstrate heightened level of anxiety and fear with each visit. Among sedative agents that could be administered enterally, dexmedetomidine may be superior due to minimal respiratory depression while providing anxiolysis and analgesia. Of note, dexmedetomidine is a highly selective alpha2-adrenoreceptor agonist that exerts its hypnotic action through activation of central pre- and postsynaptic alpha2-receptors in the locus coeruleus, mimicking natural sleep.

Official Title
-----------------
Utility of Oral Dexmedetomidine as the Sole Sedative Agent in Pediatric Population Undergoing MRI

Conditions
-----------------
Anesthesia

Intervention / Treatment
-----------------
* Drug: Dexmedetomidine
* Drug: General anesthetic


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Subjects ages 4 months to 6 years Undergoing a clinically indicated MRI with anesthesia Exclusion Criteria: Refusal to take oral dexmedetomidine Inability to take dexmedetomidine at least 90 minutes prior to start of the MRI Known allergy to dexmedetomidine Medical contraindication to administration of dexmedetomidine Unstable cardiac status including life threatening arrhythmias, abnormal cardiac anatomy, significant cardiac dysfunction Current use of digoxin Moya Moya disease New onset stroke American Society of Anesthesiologists (ASA) physical status classification system > II Contraindications to administering sedation Active and uncontrolled gastroesophageal reflux Active and uncontrolled vomiting Current or recent history of apnea Active respiratory disease including pneumonia, bronchitis, respiratory syncytial virus infection, asthma exacerbation Craniofacial anomaly Unable to have MRI

Ages Eligible for Study
-----------------
Minimum Age: 4 Months
Maximum Age: 6 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
Accepts Healthy Volunteers

Study Plan
=================
How is the study designed?
-----------------

Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Sequential Assignment
Interventional Model Description: Prospective Pilot Study, Single-site, open-label, phase I dose escalation trial
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Dexmedetomidine 12 mcg/kg<br>Group One: Subjects will receive oral dexmedetomidine 12 mcg/kg 2 hours prior to MRI | Drug: Dexmedetomidine<br>* Patients will receive oral dexmedetomidine as the sole sedative agent for undergoing MRI<br>|
| Experimental: Dexmedetomidine 18 mcg/kg<br>Group Two: Subjects will receive oral dexmedetomidine 18 mcg/kg 2 hours prior to MRI | Drug: Dexmedetomidine<br>* Patients will receive oral dexmedetomidine as the sole sedative agent for undergoing MRI<br>|
| Experimental: Dexmedetomidine 24 mcg/kg<br>Group Three: Subjects will receive oral dexmedetomidine 24 mcg/kg 2 hours prior to MRI | Drug: Dexmedetomidine<br>* Patients will receive oral dexmedetomidine as the sole sedative agent for undergoing MRI<br>|
| Active Comparator: General anesthesia control<br>Control group: Subjects will receive general anesthesia for their MRI | Drug: General anesthetic<br>* Patients will receive inhalational anesthetic to provide general anesthesia for undergoing MRI<br>|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| MRI motion artifact | The primary outcome is qualitative evaluation of MRI motion artifact. Each MRI sequence will be graded 1-3. 1: no-mild motion artifact; 2: moderate motion artifact; 3: severe motion artifact (non-diagnostic) | Immediately after the MRI scan completion | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Ramsay Sedation Score (RSS) of 4 | The secondary outcome is achieving a minimum Ramsay Sedation Score (RSS) of 4 | During and immediately after the intervention procedure. Assessments will cease once RSS return to 3 | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
Oral dexmedetomidine, Precedex