Airway Dimension Study in Children Undergoing MRI Sedated With Propofol and Dexmedetomidine

Comparison of Changes in Upper Airway Dimensions With Dexmedetomidine and Propofol in Children Undergoing MRI

Sedation is required in infants and children to successfully complete MRI while maintaining respiratory and hemodynamic stability. Limited access to the patient may pose a safety risk during MRI examination. Therefore, appropriate drugs need to be selected, administered, and titrated to achieve these objectives. Propofol is commonly used for sedation in children in the MRI setting because of its predictability, rapid onset, and offset of action. Dexmedetomidine has sedative and analgesic properties without affecting cardiovascular and respiratory stability. The rationale of this research is to assess the effect of these drugs on the upper airway and validate their use in children with upper airway disorders.

Objectives The objective of this study is to compare the changes in upper airway configuration at the level of soft palate, base of tongue and tip of the epiglottis in children sedated with dexmedetomidine and propofol in children undergoing MRI.

We hypothesize that the upper airway caliber will be smaller in children receiving propofol than with dexmedetomidine.

Primary Outcome To measure the cross-sectional area (CSA) of the upper airway at the level of soft palate, base of the tongue and epiglottis in both groups of children at high doses of propofol and dexmedetomidine and thus compare the decrease in CSA with increasing doses of both drugs.

Secondary Outcomes To measure the

• anteroposterior (AP) diameter
• transverse (Tr) diameter of the upper airway at the three levels in both groups of children at both low and high doses of propofol and dexmedetomidine and compare the decrease in AP and Tr diameter at increasing doses of dexmedetomidine.

Inclusion Criteria:

• Children undergoing MRI brain
• Age 2 - 5 yrs
• ASA I - II

Exclusion Criteria:

• OSA
• Pathology of upper airway
• Craniofacial anomalies
• Gastroesophageal reflux
• Increased intracranial pressure
• Body weight of 20% more than ideal
• Contraindication to the use of either drug
• Failure to maintain a patent airway during the study