RESUMO
BACKGROUND: Many different sedation concepts for magnetic resonance imaging have been described for prematurely and term-born infants, ranging from "no sedation" to general anesthesia. Dexmedetomidine is an alpha-2 receptor agonist that is frequently used to sedate older children, because the anesthesiologist can easily adjust sedation depth, the patient maintains spontaneous breathing, and awakens rapidly afterwards. AIMS: The present study evaluates whether dexmedetomidine could safely be used as the sole sedative for prematurely and term-born infants less than 60 weeks postconceptional age undergoing diagnostic procedures. METHODS: We performed a retrospective monocentric analysis of n = 39 prematurely and term-born infants (<60 weeks postconceptional age or a body weight <5 kg) who were sedated with dexmedetomidine for an MRI at a German university hospital from August 2016 to November 2018. RESULTS: Successful imaging was achieved in all cases. The median initial bolus of dexmedetomidine administered over 10 min was 1.39 µg kg-1 body weight (range 0.34-3.64 µg kg-1 ), followed with a continuous infusion at a median rate of 1.00 µg kg-1 h-1 (range 0.5-3.5 µg kg-1 h-1 ); however, 3 patients (7%) needed some additional sedation (ketamine or propofol). All patients, including 10 infants who had previously required respiratory support, underwent the procedure without any relevant desaturation or apnea. Bradycardia was observed in up to 15 out of 39 cases (38.5%), but only four (10.3% in total and 26.7% of bradycardia) required atropine. CONCLUSIONS: These results indicate that dexmedetomidine can be safely used for procedural sedation in the high-risk cohort of prematurely and term-born infants less than 60 weeks postconceptional age. Apnea during procedural sedation and subsequent stay in the recovery room is avoided, but bradycardia remains a relevant risk that may require treatment.
