The Effect Of Melatonin On Sedation Of Children

British Journal of Anaesthesia 97 (2): 220–5 (2006)

doi:10.1093/bja/ael144

Advance Access publication June 17, 2006

The effect of melatonin on sedation of children undergoing magnetic resonance imaging
M. R. J. Sury1 3* and K. Fairweather2 3
Department of Anaesthesia and 2Department of Radiology, Great Ormond Street Hospital for Children NHS Trust, London WC1N 3JH, UK. 3PortexAnaesthesia, Intensive Therapy and Respiratory Medicine Unit, Institute of Child Health, 30 Guilford Street, London WC1N 1EH, UK
*Corresponding author. E-mail: surym@gosh.nhs.uk
Background. Melatonin may induce a natural sleepiness and improve predictability of sedation drugs. We have investigated its clinical value in children sedated for magnetic resonance imaging. Methods. In a stratified randomizeddouble-blind study, 98 children received either melatonin or placebo 10 min before they were sedated with a standard oral regimen. Children >5 and 15 and 5 and 93% with oxygen (max 5 litres minÀ1 via a face mask or 2 litres minÀ1 via nasal cannulae) and heart rate appropriate for age (minimum 80 minÀ1)

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(patients were categorized according to the specialty thatrequested the scan). Based on previous experience, we estimated that the mean time to become sedated was approximately 40 min (SD 10 min). We calculated that we would need 44 children (22 in each treatment group) in order to have a 90% chance (at P-value 0.05%) of determining a reduction in the sedation onset time by 10 min; we therefore aimed to study 50 in each sedation group, a total of 100children. A small number of children were expected not to reach deep sedation and therefore the groups were compared with Kaplan–Meier survival analysis and logrank test: children who did not achieve deep sedation were censored at 120 min. For simplicity, time data were compared with t-tests and children who did not achieve deep sedation were treated as missing values. None of the time data wasnormally distributed except for time to deep sedation in children who received temazepam and droperidol. For consistency, all time data were transformed to log base 10 to improve the normality of data distribution. Time results are presented as geometric means (=anti-log of mean of log10 times) with anti-logs of the 2.5% lower and 97.5% upper limits of log-transformed sample data (in square brackets) tothe nearest minute. Student t-tests were performed on log-transformed data and the P-values are presented alone. The SD of the raw time to reach deep sedation is also quoted. Cox regression analysis was used to estimate the effect of single and multiple factors upon the time taken to reach deep sedation. Following a review of the results, the uniformity of both weight and content of melatonincapsules were determined on a sample of 20 capsules remaining from the clinical trial, using precision balances and a validated high-pressure liquid chromatography method.

Table 3 Patient characteristic data details. Scan length is the geometric mean in minutes with anti-logs of the 2.5% lower and 97.5% upper limits of logtransformed sample data, in square brackets Chloral Age (yr) [mean (range)]Weight (kg) [mean (SD)] Gender (M/F) I.V. cannula inserted Scan length (min) Needed sedation top-up Failed to reach deep sedation Temazepam and droperidol Age (yr) [mean (range)] Weight (kg) [mean (SD)] Gender (M/F) I.V. cannula inserted Scan length (min) Needed sedation top-up Failed to reach deep sedation Melatonin (n=25) 1.5 (0.3–4.1) 10.7 (2.5) 11/14 10 32 [18–56] 7 – Melatonin (n=24) 5.3(1.6–10.3) 21.5 (6.4) 11/13 14 30 [16–57] 12 2 Placebo (n=25) 2.0 (0.3–4.2) 11.5 (2.1) 10/15 8 35 [16–73] 7 1 Placebo (n=24) 5.6 (3.1–8.9) 22.1 (6.2) 11/13 11 31 [15–62] 10 2

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Table 4 Specialty requesting MRI. *One patient did not become deeply sedated Specialty (n) Chloral Temazepam and droperidol Placebo 5* 7 (2) 4 3 0 3 2...