377 ARTIGO ORIGINAL / ORIGINAL ARTICLE Portuguese Journal of Pediatrics Portugal Introduction Neuroimaging and electroencephalography (EEG) are important for the diagnosis, prognosis and development of interventonal strategies in paediatric neurodevelop- mental disorders. Due to the need of the child to remain stll during the imaging exam and sleep EEG, performing these tests is ofen a challenge. Thus, the use of an ade- quate sedatve agent is paramount for the success of the neurodiagnostc procedures. The Natonal Insttute for Health and Care Excellence (NICE) and the American College of Emergency Physi- cians guidelines recommend chloral hydrate for mod- erate sedaton during painless procedures in children. 1,2 However, they do not claim its superiority compared to other sedatve agents. Some studies suggest that chloral hydrate is inefectve in a signifcant proporton of chil- dren. 3,4 On the other hand, there are concerns about its safety, and gastrointestnal, cardiovascular, respiratory and carcinogenic efects have been reported. 5-7 Aim In this Cochrane Corner, we present and discuss the results of a systematc review from the Cochrane Data- base of Systematc Reviews published in 2017, which summarised and updated the existng evidence on the efcacy and safety of chloral hydrate as a sedatve agent in paediatric neurodiagnostc procedures. 8 Methods Randomised or quasi-randomised controlled trials of children (under 18 years old) who electvely underwent neuroimaging or sleep EEG requiring sedaton were included. The administraton of oral or rectal chloral hydrate was compared to other sedatve/sleep-inducing agents, alternatve therapies or no interventon. The primary outcomes included the proporton of chil- dren who successfully completed a neurodiagnostc pro- cedure without awakening, the proporton of children who required a further dose of either the same sedatve agent or the additon of a diferent sedatve agent, and the tme to adequate sedaton in minutes. The secondary outcomes were the proporton of chil- dren with sedaton failure or inadequate level of seda- ton, the sedaton duraton, sleep onset latency, EEG and neuroimaging artefact fndings, and adverse efects atributable to therapy. The review followed Cochrane’s standardised meth- odology, with a systematc search of studies published up to July 2017 in MEDLINE, CENTRAL, EMBASE and Cochrane Epilepsy Group Specialized Register data- bases. Unpublished and ongoing studies, references, guidelines, review artcles and abstracts of relevant scientfc meetngs were identfed. The risk of bias of the included studies was assessed using the Cochrane Risk of Bias Tool (2011) and the quality of evidence for the main outcomes was assessed using the GRADE approach. Authors assessed clinical heterogeneity due to clinical and methodological factors, and statstc heterogeneity was quantfed by the measurement of inconsistency (I 2 ). Diferent efect measures were used depending on the outcome, including risk rato (RR) for dichotomous var- iables and mean diferences (MDs) for contnuous vari- ables. The results were presented with 95% confdence intervals (95% CI). The meta-analysis was based on a fxed-efects model, using a random-efects model in the presence of mod- erate to high heterogeneity. COCHRANE CORNER Rita Guerreiro 1 , Ricardo M Fernandes 2,3,4 , João Crispim 1 aPort J Pediatr 2018;49:377-80 DOI: htps://doi.org/10.25754/pjp.2018.15019 Chloral Hydrate as a Sedating Agent for Neurodiagnostic Procedures in Children 1. Paediatrics Department, Hospital Garcia de Orta, Almada, Portugal 2. Paediatrics Department, Hospital de Santa Maria, Centro Hospitalar Lisboa Norte, Lisbon Academic Medical Centre, Lisbon, Portugal 3. Clinical Pharmacology Unit, Insttuto de Medicina Molecular, Faculty of Medicine, University of Lisbon, Lisbon Academic Medical Centre, Lisbon, Portugal 4. Portuguese Collaboratng Centre of the Iberoamerican Cochrane Network, Cochrane Portugal, Lisbon, Portugal Corresponding Author Rita Guerreiro ana.rita.guerreiro@hgo.min-saude.pt Paediatrics Department, Hospital Garcia de Orta, Av. Professor Torrado da Silva, 2805-267 Almada, Portugal Received: 14/09/2018 | Accepted: 18/09/2018