Intranasal Dexmedetomidine Versus Oral Midazolam as Premedication for Propofol Sedation in Pediatric Patients Undergoing Magnetic Resonance Imaging

Overview

A magnetic resonance imaging (MRI) examination usually takes 30 to 45 minutes and requires the patient to remain perfectly still during the entire acquisition process to ensure quality. Children under 6 years of age are not very cooperative and sedation is required for this age group. Currently, there are no specific recommendations for sedation for a paediatric MRI examination. In 2018, a retrospective study on the sedation protocol applied at Hôpital Universitaire des Enfants Reine Fabiola (H.U.D.E.R.F.) was conducted. In this protocol, premedication was done with oral midazolam and sedation with iterative boluses of propofol. This study concluded that the protocol in place was effective, but found that image acquisition during the procedure was interrupted in 25% of cases, largely due to involuntary movements of the child. Preoperative stress can be emotionally traumatic for the child and may even extend beyond the perioperative period, hence the importance of premedication. For the most anxious children, non-pharmacological means of premedication are often not sufficient. Moreover, the literature shows that pharmacological premedication is useful in reducing parental separation anxiety and in facilitating induction of anaesthesia. Midazolam is an effective premedication agent with some disadvantages (paradoxical reaction, low compliance of oral intake). Dexmedetomidine is a highly effective α-2 receptor agonist that can also be used as premedication according to the current literature. A report by the Pediatric Sedation Research Consortium (P.S.R.C.) shows that it has a safe profile and an incidence rate of serious adverse events of 0.36% in the paediatric population. Furthermore, administered intranasally, it is non-invasive, painless and has good bioavailability (over 80%). The primary objective is to demonstrate the superiority of intranasal dexmedetomidine over oral midazolam as a premedication for bolus sedation of propofol in terms of the incidence of any event during the MRI procedure requiring temporary or permanent interruption of the examination. The impact of dexmedetomidine on the amount of propofol administered and on the post-sedation period, the impact of external factors on the primary objective, the acceptance of intranasal premedication by the children and the quality of the MRI images will also be analyzed.