An apparent life-threatening event is defined as an episode that is frightening to the observer and is characterized by some combination of apnea (central or obstructive), skin color change (cyanosis, pallor, erythema, or plethora), marked change in muscle tone, or unexplained choking or gagging.1 In some cases, the observer fears that the child has died.1 Apparent life-threatening events occur in younger children and should not be confused with choking or gagging episodes that commonly occur during feeding or with rhinorrhea.Editor's Capsule Summary
What is already known on this topic
Apparent life-threatening events are a combination of symptoms (often transient) affecting infants that may include apnea, skin color change, changes in muscle tone, or unexplained choking or gagging. Frightened caregivers may believe the child is dying, but symptoms are commonly decreased or absent by the time paramedics or emergency department (ED) personnel evaluate the infant.
What question this study addressed
This study evaluated the incidence of apparent life-threatening events encountered by emergency medical services (EMS) providers over a 2-month period and tabulated the EMS providers' assessments of the patients and the disorders diagnosed after full ED evaluation.
What this study adds to our knowledge
Eighty-three percent of these patients appeared to be in no distress when evaluated by EMS providers. Forty-eight percent of patients whose assessments by EMS providers revealed no abnormalities were found to have significant, and occasionally life-threatening, illnesses during ED evaluation.
How this might change clinical practice
Apparent life-threatening events should be considered symptoms of significant illness, even in the presence of normal assessments by EMS providers; all should receive ED evaluation. Education and monitoring should be directed to this potentially deceptive presentation.
“Apparent life-threatening event” is a term that describes a symptom set and not a specific disease. Previous investigators have found a wide variety of illnesses and etiologies associated with apparent life-threatening events, including gastroesophageal reflux, pertussis, respiratory syncytial virus infection, urinary tract infection, metabolic disorders, cerebral lesions, cardiac dysrhythmia, anemia, primary prolonged apnea and obstructive sleep apnea, drug effects from administered drugs or medications, sepsis, dehydration, small airway patency abnormalities, tracheal and pharyngeal abnormalities, facial dysmorphia, child abuse, and factitious complaints by caregivers.2, 3, 4, 5, 6, 7, 8, 9, 10, 11 Before 1986, terminology such as “aborted crib death” and “near miss sudden infant death syndrome (SIDS)” was used to describe syndromes similar to apparent life-threatening events, but this terminology was abandoned because it was used inconsistently and was misleading in implying that there was a close association with SIDS and the symptom set now known as apparent life-threatening events.
A recent British publication reported an incidence rate of apparent life-threatening events of 0.6% per year in an infant population treated in or referred to a pediatric tertiary care center.2 The incidence rate of apparent life-threatening events for the general infant population is estimated to be between 0.5% and 6%.2, 4, 12 Because the term “apparent life-threatening event” denotes a symptom complex and is infrequently or inconsistently reported as a final diagnosis in medical records or diagnosis-related databases, the actual incidence of the condition in a general infant population is unknown.
In studies reporting outcome or final diagnosis, the etiologies of many cases of apparent life-threatening events remain unknown, whereas for other cases, the etiologies range in seriousness from grave to minor.2, 4, 13 As a further consideration, McGuire and Pointer14 reported 2 patients with apparent life-threatening events who were not transported by paramedics after evaluation in the field, suggesting that out-of-hospital personnel may discount caregiver information suggestive of an apparent life-threatening event.
The purposes of this study were to describe the demographic characteristics, clinical characteristics, and outcomes for a population of infants with apparent life-threatening events and for whom an ambulance in an urban emergency medical services (EMS) system was summoned.