Causes of apparent life threatening events in infants: a systematic review.

AIMS To determine the most likely diagnoses when infants first present with an apparent life threatening event (ALTE). METHODS Medline (1966-2002), Embase (1980-2002), and Cinahl (1982-2002) were searched. Primary authors and content experts were contacted to identify further studies. Bibliographies from studies, reviews, and textbooks were searched. Foreign language studies were translated. Articles were included if the ALTE was clearly defined and if the evaluation recorded was from the initial contact. Case reports and studies focusing on single conditions or non-clinical data were excluded. RESULTS From an initial 2912 papers, eight studies involving 643 infants (aged 0-13 months) were included. All studies were non-randomised and methodological quality varied. All diagnoses were made after evaluation in hospital but investigation protocols varied widely. There were 728 diagnoses assigned overall. Some infants had multiple diagnoses. The most common diagnoses were gastro-oesophageal reflux (n = 227), seizure (n = 83), lower respiratory tract infection (n = 58), and "unknown" (n = 169). Five deaths were noted in total. CONCLUSIONS There is a wide range of diagnoses reported after evaluation of an ALTE. Differing management protocols contributed to variations in the frequency of the diagnoses. The development and validation of an evidence based management plan may contribute to the care of this common condition.