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The assessment and management of infants who are described as
having had a frightening, perhaps life-threatening, event is a challenging
problem for clinicians. The fear that the infant may experience
additional episodes, perhaps a fatal one, heightens the anxiety
level of both families and medical professionals.
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An apparent life-threatening event (ALTE) was defined in 1986
at a National Institutes of Health (NIH) Consensus Development Conference
on Infantile Apnea and Home Monitoring as an “episode that
is frightening to the observer and that is characterized by some
combination of apnea (central or occasionally obstructive), color
change (usually cyanotic or pallid but occasionally erythematous
or plethoric), marked change in muscle tone (usually limpness),
choking, or gagging.” In addition, it was recommended that
previously used terminology such as “aborted crib death” or “near-miss
sudden infant death syndrome (SIDS)” be abandoned to avoid
implication of a causal association between this type of spell and
SIDS.1
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Apparent life-threatening events were described in the Consensus
Development Conference statement as a “chief complaint
that describes a general clinical syndrome.” This general
clinical syndrome may be secondary to a specific diagnosis or may
remain idiopathic despite a thorough evaluation. The definition
of an apparent life-threatening event appears straightforward; however,
in practice, the decision regarding whether or not an infant experienced
an ALTE can be extraordinarily difficult for clinicians. Although
more than 20 years have passed since the adoption of the ALTE definition,
the published literature regarding the epidemiology, clinical course,
and prognosis of ALTE remains limited, and there is no evidence
that these events arise from any single mechanism. Nor is there
evidence that the manifestations represent a consistent pattern.
Factors that contribute to the difficulty in studying infants who
experience ALTE episodes include the following:
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- Marked heterogeneity of clinical presentation
- Lack of signs or symptoms during initial assessment by medical
professionals
- Parents or other caretakers who have been very frightened
and have difficulty accurately describing signs or symptoms2-7
- Possibility that some signs or symptoms are fabricated or
inflicted
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Data regarding incidence of ALTEs are limited. Their incidence
is estimated to be 0.05% to 1% in population-based
studies.8-11 Some perspective on the occurrence
of idiopathic ALTE can be obtained from the Collaborative Home Infant
Monitoring Evaluation (CHIME study), which was conducted at five
medical centers (located in Cleveland, Toledo, Chicago, Los Angeles,
and Honolulu) during the mid-1990s. This study included a systematic review
of infants who presented with diagnoses consistent with ALTE and
found that a typical urban medical center hospital provides care
for about one case of possible ALTE each week and that approximately
20% of such cases will be considered an idiopathic ALTE.12
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Most commonly infants are no longer experiencing respiratory
or circulatory dysfunction by the time they are first seen by medical
professionals. Even in cases in which an emergency medical team
has been called, the signs ...