A Pilot Study to Assess the Amnesic Properties of Dexmedetomidine in Pediatric Patients

Completed

Brief Summary: The goal of this study is to determine the effects of dexmedetomidine on memory and recall of children who are receiving dexmedetomidine sedation administered for magnetic resonance imaging (MRI) studies. Dexmedetomidine is currently the standard drug for sedation for diagnostic (MRI, computerized tomography (CT) and Nuclear Medicine) radiological studies at Boston Children's Hospital (BCH). The effect of dexmedetomidine on memory and recall in children has not been studied.

Recruitment & Eligibility

Inclusion Criteria

The patient must be between 4 and 14 yrs of age and be undergoing a therapeutic or diagnostic procedure with or without sedation
The patient must be able to comprehend and perform the task (naming pictures)
The patient must have a minimum weight of 8 kg

Exclusion Criteria

Allergy to Dexmedetomidine (for those patients requiring sedation)
Procedure of short duration (< 15 min)
Pregnancy
Recent use (within 5 half-lives) of centrally acting medications that could affect concentration (e.g. diphenhydramine)

Arm && Interventions

Group	Intervention	Description
Children not undergoing sedation	Memory Test	A control group of children of similar age scheduled for MRI will be recruited to perform memory recognition testing.
Children undergoing sedation with Dexmedetomidine	Memory Test	Children who will undergo sedation for MRI will be given a memory encoding task during dexmedetomidine bolus induction to measure the effects of sedation. The mere task of naming a picture will encode that picture into memory. When the anesthesia has worn off (at approximately 1 hour later), children will be given a memory recognition task to measure the amnesic effects of dexmedetomidine.
Children undergoing sedation with Dexmedetomidine	Dexmedetomidine	Children who will undergo sedation for MRI will be given a memory encoding task during dexmedetomidine bolus induction to measure the effects of sedation. The mere task of naming a picture will encode that picture into memory. When the anesthesia has worn off (at approximately 1 hour later), children will be given a memory recognition task to measure the amnesic effects of dexmedetomidine.

Primary Outcome Measures

Name	Time	Method
Sedation Threshold	Until the child has reviewed cards and is under sedation or for the control group has reviewed 100 cards	During the 10-minute bolus infusion of Dexmedetomidine, children will be presented with pictures at 5-second intervals and asked to name the picture. They will be asked to name each picture (e.g., cat, tree, pencil, etc.). A valid response is naming of the picture within 5 seconds, either correctly or incorrectly.The important response measure is whether the child is awake enough to perform the naming task.

Secondary Outcome Measures

Name	Time	Method
Memory Threshold	Until 100 cards have been presented to the child. Approx. 10 minutes.	At the presentation of each picture, the child will be asked whether or not he/she remembers having seen it previously. Each response will be coded as correct (true positives and true negatives) or incorrect (false positives and false negatives)