Sedation in children undergoing magnetic resonance imaging comparative study between dexmedetomidine and ketamine

Aim and background
In this study we compared between sedative effect of dexmedetomidine and ketamine as regards their sedative, hemodynamic, respiratory effects and complication when given as infusions in children undergoing magnetic resonance imaging (MRI).
Methods
One hundred and ten children of both sex aged 3–7 years were randomly distributed into two groups. The first group ( = 55) received dexmedetomidine (D) l μg/kg as a loading dose followed by continuous infusion 0.5–0.75 μg/kg/h and the second group ( = 55) received ketamine (K) 1 mg/kg as a loading dose followed by continuous infusion 10–15 μg/kg/min. Inadequate sedation was defined as difficulty in completing the procedure because of movement of the child during MRI. The children who were inadequately sedated were given a single dose of propofol 0.5 mg/kg in both groups intravenously (iv) as rescue doses. Mean arterial pressure (MAP), heart rate (HR), peripheral oxygen saturation (SpO) and respiratory rate (RR) were monitored during this study.
Results
Inadequate sedation was observed in 6 children from (D) group and 4 children from (K) group during MRI examination. Onset of sedation was significantly shorter in (K) group, but the discharge time was longer in this group. MAP and HR decreased significantly from baseline during sedation in group (D). Nausea, vomiting, and dysphoria were observed in 3 children of group (K).
Conclusion
Dexmedetomidine provided adequate sedation in most of the children without hemodynamic or respiratory embarrassment, in comparison with ketamine which provided adequate sedation but with delayed discharge time and more side effects.