TOPLINE:

Intranasal dexmedetomidine supported safe paediatric MRI with 100% scan completion, with no respiratory compromise and minimal haemodynamic adverse events. However, over one third of children required rescue sedation, and older age and longer or delayed scan durations were independently associated with the need for rescue sedation.

METHODOLOGY:

• Researchers conducted a single-centre retrospective study to evaluate the safety and efficacy of intranasal dexmedetomidine for paediatric MRI sedation.
• The study included 109 paediatric patients (median age, 10 months; median weight, 8.75 kg; 60 boys) who underwent MRI under intranasal dexmedetomidine sedation at a tertiary paediatric referral centre in Italy between June and November 2024.
• Patients received an initial intranasal dexmedetomidine dose of 2-4 μg/kg via nebulisation using a mucosal atomisation device. The onset of sedation was defined as the time from drug administration to the achievement of a Ramsay Sedation Scale score of 4.
• Primary outcomes were treatment-related adverse events after intranasal dexmedetomidine (such as bradycardia, hypotension, or respiratory depression requiring intervention) on the basis of the age-adjusted Pediatric Advanced Life Support criteria, along with changes in vital signs at predefined timepoints.
• Secondary outcomes included the effectiveness of sedation — defined as successful MRI completion with diagnostic quality images or the need for rescue sedation — administered at the discretion of the attending anaesthesiologist and radiologist for motion-related image artifacts and predictors of rescue sedation.

TAKEAWAY:

• Overall, 2.8% of patients experienced bradycardia and sudden hypotension (a reduction in systolic blood pressure [BP] below 50 mm Hg) requiring an intravenous crystalloid bolus of 5 mL/kg; no respiratory depression was observed in any patient.
• The heart rate decreased significantly over time (P < .0001). Oxygenation parameters varied modestly, with significant changes seen in oxygen peripheral saturation (P = .0001) and fraction of inspired oxygen (FiO2; P = .0006); FiO2 requirements increased later in the procedure; however, oxygen saturation remained 97% or above throughout. No significant changes in systolic or diastolic BP were observed.
• All 109 MRIs (100%) were completed successfully with diagnostic quality images. The median time to sedation onset was 15 minutes, the median time to MRI start was 20 minutes, the median MRI duration was 36 minutes, and the median time to full awakening was 70 minutes.
• Rescue sedation was required in 36.7% of patients. After adjustments, independent predictors of rescue sedation were older age (adjusted odds ratio [aOR], 1.03 per month), a longer sedation-to-MRI time (aOR, 1.14 per minute), and a longer MRI duration (aOR, 1.04 per minute; P < .05 for all).

IN PRACTICE:

"[The] results align with the existing international evidence, suggesting that, when administered after an appropriate risk-benefit assessment, IN DEX [intranasal dexmedetomidine] as the sole agent for pediatric MRI sedation may represent a reliable alternative to intravenous sedative strategies," the authors wrote.

SOURCE:

This study was led by Filippo Firenzuoli, University of Florence, Florence, Italy. It was published online on April 29, 2026, in the European Journal of Pediatrics.

LIMITATIONS:

The study had a retrospective design with no control group. The attending anaesthesiologist selected the initial intranasal dexmedetomidine dose, which may have introduced selection bias. The lack of the standard rescue sedation criteria and no interrater reliability assessment for image quality may have introduced interoperator variability.

DISCLOSURES:

This study did not receive any specific funding. The authors declared having no relevant competing interests.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.