RANDOMIZED DOUBLE-BLIND CLINICAL-TRIAL OF INTERMEDIATE-DOSE VERSUS HIGH-DOSE CHLORAL HYDRATE FOR NEUROIMAGING OF CHILDREN

Orally administered chloral hydrate is the most widely used sedative i n children undergoing MRT. We compared intermediate- and high-dose ora l chloral hydrate in 97 consecutive children undergoing MRI in a prosp ective, controlled, double-blind, randomised clinical trial. There wer e 50 girls and 47 boys, mean weight (+/- SD) 14.7 +/- 6.4 kg, and mean age 38 +/- 31. The children were randomly allocated to receive chlora l hydrate syrup either 70 mg/kg (group A, n = 50) or 100 mg/kg (group B, n = 47). These two groups were not significantly-different in sex, weight, age, diagnosis or ambulatory medication. The mean initial dose (+/- SEM) was 64 +/- 2 mg/kg for group A and 93 +/- 2 mg/kg for group B. Because adequate sedation was not achieved, 14 patients in group A and 6 in group B required a second dose, giving a mean total dose of 70 +/- 2 mg/kg for group A and 96 +/- 2 mg/kg for group B. The percent age of successful examinations after the initial dose (A: 64 %, B: 87 %;p < 0.05) and the total dose (A: 92 %, B: 100 %; p = 0.14) was highe r in group B. Significant differences were found for the time of onset of sedation (A: 28 +/- 2 min, B: 21 +/- 1 min; p < 0.05), but not for the time to spontaneous awakening after the completion of the examina tion. The rate of adverse reactions was similar (A: 20 %, B: 21 %; p = 1.00). We conclude that high-dose oral chloral hydrate improves the m anagement of children undergoing MRI.