When the patient’s history and physical examination are insufficient to dismiss the possibility of ALTE, the likelihood of admission rises. Therefore, investigations are helpful in elucidating underlying conditions that may explain the ALTE, but not to rule out an ALTE.

The emergency department work-up can be separated based on suspicion of particular etiologies.

An infant with:

1. Viral symptoms may benefit from a nasopharyngeal swab for viruses.
2. Suspected bacterial infection may benefit from a partial or full septic work-up (although a very small proportion of these patients will have positive findings, and are often younger than 60 days^3,4).
3. Suspected seizure may benefit from an extended electrolyte assessment (i.e., sodium, chloride, potassium, ionized calcium, magnesium, and phosphate).
4. Severe cough may benefit from an Auger suction for pertussis.
5. Suspected respiratory or cardiac involvement may warrant a chest radiograph or electrocardiogram.
6. Tachypnea, altered level of consciousness, failure to thrive, or recurrent vomiting may require investigations for an inborn error of metabolism.
7. Potential neurological etiology may benefit from neuroimaging or electroencephalogram.
8. Suspected intentional or unintentional poisoning may warrant a toxic screen and/or skeletal survey.

GERD

The connection between GERD and ALTE is long debated. It deserves separate discussion, as up to 25% of ALTE admissions can be attributed to it. Whether GERD can lead to SIDS is not yet determined, but the current level of evidence suggests this to be unlikely.⁵ An infant with a history of recurrent vomiting does not yet qualify for the diagnosis of GERD.⁶ Nevertheless, if a history of apnea immediately following vomiting or aspiration is suspected, the diagnosis of GERD is not critical for revealing the cause of the apnea. The diagnosis of GERD is more important in predicting the likelihood of recurrence or allowing targeting of potential therapies.

The probability of SIDS following an aspiration, regardless of GERD, is believed by many clinicians to be extremely low. The evidence for that assumption remains vague because of nonspecific findings on autopsy, both for laryngospasm induced by aspiration and for SIDS, itself. An infant who presents to the emergency department with a history of choking accompanied by facial flushing or breath holding, immediately after or during vomiting, has a high likelihood of aspiration-induced laryngospasm. No physiological compromise seems to have occurred. Therefore, in an otherwise healthy infant, discharge of such infants would appear reasonable. Reassuring the caregivers and ensuring appropriate follow-up is the appropriate and usual disposition for those patients.