Case
An emergency medical services (EMS) telemetry call notified the ED of an 8-week-old infant who had turned blue during a choking and coughing episode at home. While en route to the ED, the EMS technicians stated that the infant was currently appearing well, with the following vital signs: heart rate, 122 beats/minute; respiratory rate, 30 breaths/minute; and blood pressure, 90/54 mm Hg. They also noted that the infant’s oxygen saturation was 100% on room air. At the time of the call, the patient’s estimated time to arrival at the ED was 5 minutes.
When the patient arrived at the ED, followed by his tearful mother, the emergency physician (EP) noted that the infant was alert and in no acute distress. The patient was triaged and placed on a cardiorespiratory monitor while the EP spoke with his mother. The infant’s mother stated that the event occurred approximately 15 minutes after she had finished breastfeeding the patient and had placed him on his back in his crib. She said that she had heard her son making choking and gurgling sounds and had gone back to his room to check on him, whereupon she noticed that his face had turned purple. She further noted that when she picked her son up, he was limp and did not seem to be breathing. She immediately shouted for her husband to call EMS while she “blew air into his mouth.” After about 10 seconds, she said her infant responded and seemed to be back to his normal self by the time EMS arrived.
With respect to history, the mother reported her son was born via normal vaginal delivery at 39 weeks gestation and that there were no complications during pregnancy or delivery. After the standard 48-hour inpatient stay, both mother and patient were discharged home together and had been doing well up until the time of the incident.
The patient, who was up to date on his routine preventive pediatric-care visits, was in the 85th percentile for height, weight, and head circumference. Regarding his feeding routine, the patient was exclusively breastfed and, according to his mother, he tolerated his feedings well and did not typically spit-up afterward. The patient was not taking any medications. He resided at home with both his mother and father and did not attend daycare.
The physical examination showed a well-appearing 8-week-old boy, who acted appropriately for his age and was breathing comfortably on room air. His temperature at presentation was 98.4˚F, and his mother reported no history of fever. The patient’s fontanel was soft and flat, his lungs were clear on auscultation, and he had no murmurs. The abdomen was soft and without mass or hepatosplenomegaly. There were no rashes, bruises, or birthmarks.
After the examination, the patient’s mother, who was understandably distressed, asked the EP if she could breastfeed her son. As the EP prepared to answer this question, several questions came to mind: (1) Is this an apparent life-threatening event (ALTE)? (2) Is there a way to stratify this child’s risk for coexistent serious illnesses? (3) Will this patient be cleared for discharge from the ED today? (4) What tests should be ordered during his stay in the ED?
Overview
Few pediatric diagnoses result in as much consternation and uncertainty as the nebulous ALTE. The term was established to describe a spectrum of symptoms with a great number of possible underlying etiologies, and its definition leaves much room for interpretation. According to the 1986 National Institutes of Health Consensus Development Conference on Infantile Apnea and Home Monitoring, an ALTE is “an episode that is frightening to the observer, that is characterized by some combination of apnea (centrally or occasionally obstructive), color change (usually cyanotic or pallid, but occasionally erythematous or plethoric), marked change in muscle tone (usually marked limpness), choking or gagging. In some cases, the observer feels that the infant has died.”1
Parents, as well as some providers, may have misconceptions about the relation of ALTE to sudden infant death syndrome (SIDS). While ALTEs were previously considered to be “near-miss SIDS” or “aborted crib death,” fewer than 8% of SIDS patients have a history of ALTE prior to death.2 Additionally, rates of ALTE peak before 2 months of age, whereas SIDS rates are highest between 2 and 4 months of life.3
Apparent life-threatening events are less prevalent in preterm patients compared to their full-term counterparts—though most study cohorts are comprised of full-term infants. When ALTEs, however, do occur in preterm infants, EPs should have a higher index of suspicion for an undiagnosed medical etiology associated with the patient’s prematurity—one that may potentially place the patient at an increased risk for SIDS (eg, limited pulmonary functional residual capacitance, hypoxic ischemic encephalopathy leading to seizure disorder).