RESUMO
INTRODUCTION: Melatonin has been studied and used for several years as a sleep-wake cycle modulator in patients with sleep disorders. Experimental evidence has demonstrated the multiple neuroprotective benefits of this indoleamine secreted by the pineal gland. Melatonin is also used in neurological investigations, for its ability to induce sleep in children. In fact, it favors falling asleep during electroencephalogram, Magnetic Resonance Imaging (MRI), and during brainstem auditory evoked potentials. Previous studies are focused on infants and children. No investigation have been performed in neonates, before or during instrumental assessments. MATERIAL AND METHODS: One hundred ten newborns (term and preterm) undergoing brain MRI were enrolled in the study. Thirty minutes before the planned time for the examination, we administered a single dose solution of melatonin- tryptophan-vitamin B6. Twenty minutes after the initial administration of 2 mg, a second dose of 1 mg was administered, if the baby was still awake. If after further 15 min the baby was still not sleeping, an additional dose of 1 mg was administered. RESULTS: In 106 patients we obtained adequate sedation without adverse events, allowing us to perform an adequate quality MRI, with a median time of 25 min to reach sleeping. Only in three patients MRI could not be performed. In patients having a large weight, higher doses of melatonin were necessary to reach sleeping. Considering the pro kg dose of melatonin, the average dose that induced sleepiness in neonates was 0,64 ± 0.16 mg/Kg. CONCLUSION: A solution based on Melatonin- tryptophan-vitamin B6 can be a helpful sedative to administer to neonates undergoing brain MRI, avoiding the use of anesthetics and achieving adequate assessments.