An apparent life-threatening event (ALTE) is the sudden occurrence of certain alarming symptoms such as prolonged periods of no breathing (apnea), change in color or muscle tone, coughing, and gagging in children under 1 year of age.
ALTE is not a specific disorder. It is a group of symptoms that occur suddenly in young children. Although ALTE would seem to be related to sudden infant death syndrome (SIDS—see Sudden Infant Death Syndrome (SIDS)), there is no clear relationship between the two disorders.
The most common causes of ALTE include gastroesophageal reflux disease, nervous system disorders (such as seizures or brain tumors), and infections (such as meningitis). Less common causes include heart disorders, metabolic disorders, child abuse, and narrowing or complete blockage of the airways. A cause cannot be determined in about 50% of cases.
An ALTE usually is characterized by an unexpected, sudden change in an infant's breathing that alarms the parent or caretaker. Features of an event include some or all of the following:
When an ALTE occurs, the doctor asks several key questions:
The doctor does a physical examination to check for obvious defects, particularly nervous system abnormalities, such as being too stiff (posturing) or being too floppy (poor muscle tone), and signs of injury.
The doctor may do laboratory tests (blood [including liver function], stool, urine, and spinal fluid studies), imaging tests (such as a chest x-ray or computed tomography [CT] of the head), electrocardiography, or a combination of tests based on the infant's examination findings. Other tests to check for possible seizure activity (such as electroencephalography―see Electroencephalography) also may be done.
The cause, if identified, is treated. Infants who have required CPR, have had any abnormalities identified during the examination or initial laboratory testing, or whose ALTE history is concerning to the doctor are hospitalized for monitoring and further evaluation.
Parents and caregivers should be trained in CPR for infants and in general safe infant care (such as putting infants to sleep on their back and eliminating exposure to tobacco smoke). Doctors sometimes recommend home apnea monitoring devices for a limited period of time. Monitors that can record the infants' breathing pattern and heart rate are preferred to those that simply sound an alarm. Recording monitors may help doctors distinguish false alarms from real events.
Last full review/revision October 2012 by Elizabeth J. Palumbo, MD