An ALTE, or apparent life-threatening event, is defined somewhat nebulously. Essentially, it is a frightening episode involving a combination of apnea, change in color or tone, choking or gagging. The differential diagnosis for an ALTE is broad, ranging from relatively benign conditions such as gastro-esophageal reflux to congenital heart disease or child abuse.
The era of reflexive invasive testing for ALTE is coming to an end
An ALTE, or apparent life-threatening event, is defined somewhat nebulously. Essentially, it is a frightening episode involving a combination of apnea, change in color or tone, choking or gagging. The differential diagnosis for an ALTE is broad, ranging from relatively benign conditions such as gastro-esophageal reflux to congenital heart disease or child abuse. We know what to do when these kids come in looking sick; we throw the kitchen sick at them. But however scary the description of an ATLE is, because these kids usually look perfectly well in the ED, we have a hard time pulling the trigger on a big work-up, especially an expensive or invasive one.
In September’s Pediatric Pearls segment of EM:RAP, our own Dr. Ilene Claudius tackled this dilemma in an interview with ALTE guru Dr. Joel Tieder of Seattle Children’s Hospital. In July’s EPM, Dr. Ghazala Sharieff wrote an excellent Q&A style evidence-based review on the subject.
Dr. Tieder and an expert panel were asked by the Society of Hospital Medicine to comb the world’s literature and create evidence-based guidelines for the management of children presenting with ALTE. The panel sought to answer three practical questions: 1) Which features of the history and physical examination (H&P) identify high-risk patients? 2) What laboratory and/or radiological tests help us identify risk? 3) Are there criteria we can use to determine which patients require hospital admission? Of the 1200 potential articles the panel found related to ALTE or Sudden Infant Death Syndrome, only 37 were relevant and most were small, observational, non-randomized, and retrospective. Despite a paucity of evidence to work with, the panel made some interesting observations.
H&P- Across all studies, one resounding message was clear: a thorough history and physical examination is paramount and far more likely to correctly identify the cause of an ALTE than any screening test. Several high-risk features were identified including age, respiratory infection, multiple episodes, concern for child maltreatment, and underlying medical conditions. Infants less than two months old and ex-premies were consistently at high risk for having another event or a significant underlying condition. Congenital anatomical abnormalities are likely to be recognized within two months of birth and are often associated with respiratory symptoms or feeding difficulty. Of special note, bronchiolitis and pertussis can present solely with apnea in these very young patients. Child maltreatment is an important cause of ATLE; the panel estimated that it comprised 2-3% of all cases while previous estimates have been much higher. Child maltreatment is a critical diagnosis to make, as it is associated with significant mortality if undiagnosed. Conversely, while no studies specifically sought low-risk criteria, well appearing, otherwise healthy, full term infants over two months old presenting with a single event seem to be at low-risk.
TESTING- The data does not support routine testing for children presenting after an ALTE. Studies show no increased risk of serious bacterial infection (SBI) in afebrile ALTE patients compared with controls. A complete blood count (CBC) is the most commonly ordered test and while the results are often abnormal, they almost never contribute meaningfully to patient care. Laboratory and radiological tests should be directed by the H&P. This means doing septic workups for infants who are febrile, toxic appearing, or who have had a significant infectious exposure; CT or MRI, skeletal survey, and social work consultation when there is concern for abuse; toxicological, metabolic, and endocrine tests if the H&P is suggestive; electro- and echocardiograms with a history of feeding difficulties or a murmur on examination. If the H&P does not point you in a specific direction, what these babies really need is the test of time.
DISPOSITION– Naturally, the high-risk infants should be admitted to a monitored setting. Dr. Claudius asked Dr. Tieder, “for low-risk patients with reliable parents, do we need to observe them for a period in the ED before we send them home?” His answer? It’s a judgment call. There is no required period of observation. It is up to the clinician to decide when they’re comfortable sending a child home after a complete and accurate H&P. In some cases, this may mean observing both the patient and family for a while as they are interviewed by a social worker.
It may take years to build more specific evidence-based guidelines for the definition and management of ALTE. In the meantime, the role of the EP has been somewhat clarified: identify high-risk infants, admit them to a monitored setting, and initiate a directed diagnostic workup only when indicated. It may seem absurd in our current clinical milieu to admit a patient without “basic” labs and imaging, but the era of reflexive invasive testing for ALTE is coming to an end.
Dr. McCormick is a fourth year EM resident at Los Angeles County/USC Medical Center.
Dr. Swadron is an Associate Professor of Clinical Emergency Medicine at the Keck School of Medicine of the University of Southern California. EM:RAP is a monthly audio program that can be found EMRAP.org