A Pilot Study of Dexmedetomidine-Propofol in Children Undergoing Magnetic Resonance Imaging
Condition: Epilepsy; Cerebral Palsy; Developmental Delay
MeSH terms: Cerebral Palsy
Intervention: Dexmedetomidine bolus and high infusion-Propofol; Dexmedetomidine bolus and low infusion-Propofol; Dexmedetomidine bolus only - Propofol
Intervention description: First, the investigators will administer dexmedetomidine 1mcg/kg over 5 minutes. Next, the investigators will begin an infusion at 1mcg/kg/hour. At the 5 minute point, propofol will be given (2-3mg/kg bolus followed by 100mcg/kg/min infusion). The attending clinician will determine whether or not the child is in an adequate state to begin the MRI scan. If the sedative effect of the dexmedetomidine-propofol does not produce a sufficiently sedated state within 10 minutes, a repeat bolus of propofol 2mg/kg will be administered. The dose of Dexmedetomidine will not be changed. The dose will be repeated if the child is not adequately sedated in 2 more minutes. At this time infusion rate of propofol will be increased to 200 mcg/kg/minute. If the child is not sedated in 5 more minutes, the outcome will be recorded as a technique failure and sedation will continue at the discretion of the anesthesiologist.; First, the investigators will administer dexmedetomidine 1mcg/kg over 5 minutes. Next, the investigators will begin an infusion at 0.5mcg/kg/hour. At the 5 minute point, propofol will be given (2-3mg/kg bolus followed by 100mcg/kg/min infusion). The attending clinician will determine whether or not the child is in an adequate state to begin the MRI scan. If the sedative effect of the dexmedetomidine-propofol does not produce a sufficiently sedated state within 10 minutes, a repeat bolus of propofol 2mg/kg will be administered. The dose of Dexmedetomidine will not be changed. The dose will be repeated if the child is not adequately sedated in 2 more minutes. At this time infusion rate of propofol will be increased to 200 mcg/kg/minute. If the child is not sedated in 5 more minutes, the outcome will be recorded as a technique failure and sedation will continue at the discretion of the anesthesiologist.; First, the investigators will begin by administering dexmedetomidine 1mcg/kg over 5 minutes. When this is completed, they will administer propofol 2-3mg/kg titrated bolus followed by 100mcg/kg/min infusion which can also be titrated up or down to a maximum of 300mcg/kg/min to keep the blood pressure and heart rate within 30% of baseline levels.
Intervention MeSH terms: Dexmedetomidine; Propofol
Phase: Phase 4
Study type: Interventional
Primary purpose: Health Services Research
Allocation: Non-Randomized
Intervention model: Parallel Assignment
Masking: None (Open Label)
Enrollment: 71.0
Sex: All
Minimum age: 1 Year
Maximum age: 12 Years
Healthy volunteers: No
Keywords: pediatrics; sedation; dexmedetomidine; propofol; MRI

Summary:

      This is a pilot study to determine if a standard bolus dose and infusion of dexmedetomidine
      can significantly decrease the dose of propofol (infusion) required for accomplishing an MRI.
      The investigators studied three arms to examine the effectiveness of dexmedetomidine. Arm 1
      was a single bolus of 1.0 mcg/kg with 1.0 mcg/kg/hr infusion followed by propofol infusion.
      Arm 2 was a bolus of 1.0 mcg/kg with 0.5 mcg/kg/hr infusion followed by propofol infusion.
      Arm 3 was only a single bolus of 1.0 mcg/kg with no infusion followed by propofol infusion.
    

Eligibility criteria:

        Inclusion Criteria:

          1. Subjects presenting as out-patients, scheduled to receive an anesthetic for MRI of
             body (spine, chest, abdomen, and/or pelvis) and/or extremity (arm and/or leg).

          2. The subject must be a candidate for the sedation technique described in this study
             with a natural airway (see exclusion criteria described below). This decision will be
             made by a staff member of the Department of Anesthesiology.

          3. The subjects must be 1 and 12 years.

          4. The subject's legally authorized representative has given written informed consent to
             participate in the study.

          5. American Society of Anesthesiologist status I, II, or III

        Exclusion Criteria:

          1. The subject is residing in the Pediatric Intensive Care Unit, the Cardiac Intensive
             Care Unit, or Neonatal Intensive Care Unit.

          2. Diagnosis of a difficult airway or severe obstructive sleep apnea that is not
             compatible with spontaneous ventilation in a supine position.

          3. Congenital heart disease or history of dysrhythmia.

          4. Patient taking digoxin or beta-blocker

          5. Anxiolytic medication is ordered before the MRI (e.g., midazolam or ketamine).

          6. The subject has a history or a family (parent or sibling) history of malignant
             hyperthermia.

          7. The subject is allergic to or has a contraindication to propofol or dexmedetomidine.

          8. The subject has previously been treated under this protocol.

          9. The subject has a tracheostomy or other mechanical airway device.

         10. The subject has received within the past 12 hours an oral or intravenous
             alpha-adrenergic, beta-adrenergic agonist, or antagonist drugs (e.g., clonidine,
             propranolol, albuterol).

         11. The subject is not scheduled to receive anesthesia-sedation care for the MRI.

         12. The subject received one of the anesthetic regimens for the same MRI during the past
             six months.