A Pilot Study of Dexmedetomidine-Propofol in Children Undergoing Magnetic Resonance Imaging
Condition: Epilepsy; Cerebral Palsy; Developmental Delay
MeSH terms: Cerebral Palsy
Study type: Interventional
Phase: Phase 4

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.
    

Detailed description: 
      A recent publication in the New England Journal of Medicine highlighted the accumulating
      evidence for neurotoxic effects of anesthetics in animal models and a collection of
      epidemiologic studies in humans. Recent studies of anesthesia in fetal and neonatal primates
      are yielding more evidence of neurotoxicity associated with many common anesthesia and
      sedation techniques (e.g. propofol, etomidate, sevoflurane, desflurane and isoflurane). On
      the other hand, the data suggests that some alternative sedative agents, such as
      Dexmedetomidine, may not have the same neurotoxic effect.

      Children routinely undergo sedation for MRI scanning with large doses of propofol and other
      sedatives. Many of these scans occur at young ages when these children may be at risk of
      neurological injury from sedative exposure. In addition, these scans do not involve any
      stimulation - which could be protective against neurodegeneration.

      The investigators propose 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. Based on previous work with the combination of propofol with
      dexmedetomidine for other procedures, the investigators propose a standard dose of
      dexmedetomidine (1 mcg/kg bolus followed by an infusion at 1.0 mcg/kg/hour, 0.5 mcg/kg/hour,
      or no infusion). The investigators will augment this sedation with propofol 2-3 mg/kg
      titrated bolus followed by 100 mcg/kg/min infusion which can also be titrated up or down to a
      maximum of 300 mcg/kg/min to keep the blood pressure and heart rate within 30% of baseline
      levels).

      The investigators hypothesize that the use of low dose propofol with dexmedetomidine will be
      effective undergoing MRI while sparing exposure to the high dose of the sedative.
    

Intervention name(s): Dexmedetomidine bolus and high infusion-Propofol; Dexmedetomidine bolus and low infusion-Propofol; Dexmedetomidine bolus only - Propofol
Intervention type(s): Drug; Drug; Drug
Intervention description(s): 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.
Other intervention name(s): Dexmedetomidine-Propofol; Dexmedetomidine-Propofol; Dexmedetomidine-Propofol
Intervention MeSH terms: Dexmedetomidine; Propofol
Allocation: Non-Randomized
Intervention model: Parallel Assignment
Masking: None (Open Label)
Primary purpose: Health Services Research
Keywords: pediatrics; sedation; dexmedetomidine; propofol; MRI