Etiology and Outcome of Severe Apparent Life-Threatening Events in Infants.

Introduction: An apparent life-threatening event (ALTE) is defined as "an episode that is frightening to the observer and is characterized by some combination of apnea, color change, marked change of muscle tone, choking, or gagging."

Objective: The aims of this study were to determine etiology and outcome of severe ALTE (requiring resuscitation measures) and to review diagnostic approaches in infants hospitalized after such an episode of ALTE.

Methods: Retrospective analysis included patients hospitalized at the Intensive Care Unit, Institute of Child and Youth Healthcare of Vojvodina, after an episode of severe ALTE over a 4-year period.

Results: The study included 23 infants, 18 male (78.3%), and 5 female (21.7%). The average age at presentation was 78 days (1 day to 11 months). In 8 infants (34.7%), ALTE resulted in death. The most frequent conditions after diagnostic evaluation were lower respiratory tract infections (39.1%), intracranial and extracranial hemorrhages (13.0%), and central nervous system infections (8.6%). The cause remained unknown in 8.7% of cases. Initial investigations included complete blood cell count, C-reactive protein or procalcitonin, blood gasses, lactate, electrolytes, glucose, blood culture, urinalysis, and chest x-ray.

Conclusions: Apparent life-threatening event represents a diverse disorder. Lower respiratory tract infections and neurological disorders were the most common established etiology. Prematurity and congenital heart diseases stood out as important risk factors. Diagnostic evaluation varied according to suspected cause and trigger factors.