Purpose Although chloral hydrate (CH) has been used as a sedative for decades, it is not widely accepted as a valid choice for ophthalmic examinations in uncooperative children. This study aimed to systematically review the literature on the drug's safety and efficacy.

Methods We searched PubMed, EMBASE, ISI Web of Science, Scopus, CENTRAL, Google Scholar and Trip database to 1 October 2015, using the keywords ‘chloral hydrate’, ‘paediatric’ and ‘procedural sedation OR diagnostic sedation’. A meta-analysis of randomised controlled trials (RCTs) was performed.

Results A total of 6961 articles were screened and 104 were included in the review. Thirteen of these concerned paediatric ophthalmic examination, while 13 others were RCTs and were meta-analysed. CH was reported to have been administered in a total of 24 265 sedation episodes in children aged from <1 month to 18 years. The meta-analysis showed CH had a higher OR (2.95, 95% CI 1.09 to 7.99) for successful sedation compared to other sedatives, but significant limitations apply. The commonest reported adverse events (AE) were not serious (eg, paradoxical reaction or transient vomiting) and required no intervention. Severe AE, including two deaths, were related to comorbidity, overdose or aspiration.

Conclusions Despite the paucity of high quality evidence, the existing literature suggests that the use of CH for procedural sedation in children appears to be an effective alternative to general anaesthesia, and it can be safe when administered in the hospital setting with appropriate monitoring and vigilance for intervention.