Chloral hydrate in pediatric magnetic resonance imaging: evaluation of a 10-year sedation experience administered by radiologists



Chloral hydrate is a sedative that has been used for magnetic resonance imaging (MRI).


To evaluate the use, effectiveness and safety of chloral hydrate administered by radiologists for the sedation of children who require MRI procedures.

Materials and methods

We retrospectively reviewed the clinical charts for all patients ages 0 – 10 years old who underwent sedation with chloral hydrate for MRI from January 2000 to December 2010. Demographic factors, dose information, indication for MRI, therapeutic failures and adverse reactions to the drug were reviewed.


One thousand, seven hundred and three children (946 males, 757 females) with a median age of 2.5 years (range: 4 days – 9.91 years) received chloral hydrate. Moderate to deep sedation was achieved in 1,618/1,703 (95%) of the patients, 35/1,703 (2.1%) of the patients failed to achieve moderate to deep sedation, and 47/1,703 (2.8%) of the patients woke up during MRI examination. Adverse reactions were present in 31/1,703 (1.8%) of the patients. Three severe adverse reactions occurred (0.18%). A single dose of chloral hydrate (40–60 mg/kg) was administered to 1,477/1,703 patients (86.7%). An additional dose of chloral hydrate (10–20 mg/kg), given 15 min after the first dose or when the patient woke up during the MRI examination, was required in 226/1,703 patients (13.3%). The likelihood of requiring an additional dose in children older than 2 years was 2.2 times the likelihood compared to children younger than 2 years (OR = 2.2 [95%CI: 1.6–3.0]). The use of a reduced dose (<50 mg/kg) was not associated with a higher therapeutic failure rate (OR = 1.04 [95%CI 0.57–1.89]).


Chloral hydrate is an appropriate sedation option for pediatric patients in MRI services when strict patient selection criteria are met. The use of a reduced dose does not affect the effectiveness of sedation. The lack of data regarding the presence of transient oxygen desaturation, the time to induce sedation and the exact duration of sedation are limitations of this study.

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We want to thank all the nurses in our department who, with their professionalism and hard work, provided a safe and comfortable environment for the sedation to the children.

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Correspondence to Jorge A. Delgado.

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Delgado, J., Toro, R., Rascovsky, S. et al. Chloral hydrate in pediatric magnetic resonance imaging: evaluation of a 10-year sedation experience administered by radiologists. Pediatr Radiol 45, 108–114 (2015).

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  • Chloral hydrate
  • Children
  • Sedation
  • Magnetic resonance imaging