Assessing Apparent Life-Threatening Events in Infants

Learning Objectives

• Identify the major indicators of apparent life-threatening events (ALTEs).
• Learn how to assess pediatric patients who may have experienced an ALTE.
• Understand the transport considerations when treating a patient who experienced an ALTE.

Key Terms

• Apparent life-threatening event: An episode during which an infant becomes pale or cyanotic; chokes, gags, or has an apneic spell; or loses muscle tone.
• Sudden infant death syndrome: The unexpected and sudden death of a seemingly normal and healthy infant that occurs during sleep and with no evidence of disease.

You’re called for a “baby not breathing” at a residence. You’re responding mutual aid to the EMS responders in a neighboring community so your response is delayed. You proceed to the scene with lights and sirens, but just as you arrive, your dispatch center reports the family has called back to cancel the ambulance, stating the baby is now breathing and crying normally.

Since you’re pulling into the scene, you decide to go inside to confirm what has been relayed to you. The residence is a low-income home with children’s toys all over the front yard.

You tell the person who greets you at the front door you want to talk to the parents and see the baby. A very young father is holding a wailing infant. He tells you he was holding the baby a few minutes ago when she suddenly went limp and turned blue. He says he then held her by her feet and pounded her on the back and she started crying. She’s been responding normally since then. He says he doesn’t have insurance and doesn’t want to incur a bill for ambulance transport.

Apparent Life-Threatening Event
An apparent life-threatening event (ALTE) is defined as an episode that’s frightening to the observer and is characterized by some combination of apnea, color change, change in muscle tone, and choking or gagging.¹ ALTE replaced misleading terms such as “near-miss sudden infant death syndrome (SIDS),” which implied a direct association between this term and SIDS.²

ALTEs should be viewed as a manifestation of other conditions, rather than as a diagnosis in and of itself.³ The term is generally applied to pediatric patients and 74% of patients who presented with an ALTE in one study were younger than 2 months.⁴

The apnea may be central or obstructive, the color change may be cyanosis, pallid, erythematous or plethoric, and the change in muscle tone is usually diminished. Although ALTEs would seem to be related to SIDS, there’s no clear relationship between the two.⁵ However, the risk of SIDS increases with a history of ALTEs linked to central hypoventilation syndrome, seizures or arrhythmias.¹ This article will address the appropriate EMS assessment and management for patients who present with an ALTE.

Causes of ALTEs
The true frequency of ALTEs is unknown, but the estimate of its frequency in healthy term infants is 0.5—0.6%. Approximately 50% of these infants are ultimately diagnosed with an underlying condition that explains the ALTE.³ The other 50% are often idiopathic, causing great concerns to parents as well as physicians.³ Primary causes include:⁶

• Gastroesophageal reflux disease (26%);
• Pertussis (9%);
• Lower respiratory tract infection (9%);
• Seizure (9%);
• Urinary tract infection (8%);
• Factitious illness (3%); and
• Miscellaneous causes (11%).

Other causes include congenital and acquired disorders, physical abuse, arrhythmias, metabolic diseases, seizures and even cardiac tamponade. Although toxic ingestions are uncommonly the cause of ALTEs, one recent study described a previously unreported cause: ethanol ingestion in two infants under 2 months old.⁷ This study suggested that ethanol intoxication may be an under-recognized cause of an ALTE.

In most cases the infant is free of symptoms by the time EMS arrives, so it’s tempting to conclude the infant is doing well and doesn’t need transport. Parents may not want to incur a charge for ambulance transportation, but should be highly encouraged to have the child transported for a full evaluation in an ED. The SIDS rate for infants with an ALTE who required CPR was found to be 10% in one study, and increased to 28% with multiple ALTEs.⁸

Anatomy of the Pediatric Airway
There are critical differences between the adult airway and the pediatric airway that EMS providers need to be keenly aware of. Children have short, thick necks. Their airway is also much smaller than an adult airway, making it more prone to obstruction either by inhalation of a foreign body, inflammation, or even by the child’s disproportionately large tongue.⁹

Infants are obligate nose breathers; nasal obstruction with mucus can bring on significant respiratory distress. Infants and children also have a floppy epiglottis, which is U-shaped. This anatomical feature can make intubation difficult. The narrowest part of a child’s airway occurs at the level of the cricoid cartilage, not at the vocal cords as in adults.⁹

EMS Assessment of ALTEs
Appropriate evaluation and management of an ALTE should be individualized, since the presentation can result from many underlying conditions. EMS should take a thorough history and perform a complete physical examination. Key historical questions include:

• Who observed the event?
• How does the observer describe the event?
• Has the infant had a similar event in the past?
• What precipitated the event?
• Was the infant asleep or awake before the event occurred?
• Was the infant limp, or was there increased muscle tone or seizure activity?
• What did the infant look like during the event? What color was their skin?
• Was resuscitation required, or did the event resolve spontaneously?
• Was the infant premature? Were there any complications during pregnancy? Did the mother use any drugs during pregnancy?
• When feeding, does the child cough, gag or vomit?
• Does the infant have any health issues or take any medications?
• Are there any factors predisposing the infant to sepsis?
• Does the infant show symptoms of reflux or aspiration of thin liquids such as choking?
• Is there a family history of seizures, metabolic disorders, SIDS or unexplained infant death?

It’s important to carefully assess for airway obstruction: Determine if the airway is open and check for blood, mucus and foreign objects in the nose, mouth and airway. Children are well-known for ingesting small objects, and for placing them into the nares. This can be a cause of airway obstruction and should be closely investigated.

Note whether the child exhibits good chest rise, or whether retraction is present. Calculate the respiratory rate and auscultate the chest for abnormal breath sounds, such as wheezing, rales or rhonchi. Note whether stridor is present. (See Table 1, below).

Use pulse oximetry to get an oxygen saturation reading, remembering that hypothermia or poor perfusion may alter these readings. Carefully document the respiratory rate and pattern, and pulse oximetry reading. Provide supplemental oxygen if appropriate.

A full head-to-toe examination of the infant is also warranted, but remember: In many cases the child will have a normal physical examination. Take a full set of vital signs, including temperature. Note a general impression of the child, including any dysmorphic features or obvious malformations.

Be aware of any nervous system abnormalities, such as poor muscle tone, posturing, lateralizing signs, or focal seizure activity. Abdominal bruising, skin lesions, or signs of trauma should be noted, and long bones palpated for fractures.

Examine the head for bruising or hematomas. Abdominal distention or tenderness can indicate intestinal obstruction. Evaluate the infant’s responsiveness, whether they appear lethargic and whether muscle tone is appropriate for age.

EMS is in a unique position to observe the child’s living conditions and can report the possibility of abuse or accidental drug ingestion to the emergency physician. Does the child have reliable caretakers? Is the child well nourished? Does the child respond appropriately to EMS personnel? Does the home situation indicate a potential for abuse?

Table 1: Normal respiratory rates by age

Transport of ALTE Patients: High Risk for No-Loads
Do these infants require EMS transport? Unequivocally, the answer to the transport question is “yes.” Many EMS services now have specific protocols for ALTEs that caution against patient refusals. Almost all ALTE patients require hospitalization for observation and/or further workup.¹

A “no-load” on an ALTE patient can expose EMS providers to significant liability if the patient subsequently has another event. If parents or caretakers refuse transport, it’s important to consult with online medical control to discuss the patient’s specific situation and the need for transport. Infants with an ALTE are high-risk patients.

Infants younger than 1 month with multiple ALTEs were found to be at higher risk for additional events, or diagnoses that required further in-hospital evaluation.¹⁰

Hospital treatment will vary depending upon the etiology of the event. According to one study, most infants should be hospitalized for cardiorespiratory monitoring for 23 hours after an ALTE.¹¹ The infant may require blood work, antibiotic therapy, or treatment for gastroesophageal reflux.

Although some low-risk infants will subsequently be discharged from the ED if reliable caretakers are present, a follow-up to determine the cause of the event will be recommended. Home apnea monitors are sometimes recommended, particularly those that record the infant’s breathing pattern and heart rate.

Much like the near-drowning patient, although the child may be asymptomatic at the time EMS arrives, it’s important he or she be fully evaluated with laboratory and radiology studies as appropriate. These clinical studies aren’t currently available in the prehospital setting, so infants should be transported for additional evaluation. Transport to an appropriate hospital destination with pediatric capabilities without delay.

A recent study reviewed the mortality after discharge in clinically stable infants admitted with a first-time ALTE.¹² The study reviewed 366 charts, 176 of which met inclusion criteria. Patients with an ED diagnosis of an ALTE, seizure, choking, or cyanosis were reviewed by two of three physicians. In the study group, two patients had died within two weeks of the ED visit; neither of them had a positive diagnostic evaluation in the ED. In both cases, the cause of death was listed as pneumonia. This study concluded that the risk of subsequent mortality in infants admitted from a pediatric ED with an ALTE was substantial, and that emergency physicians should consider routine admission for patients with an ALTE.

Conclusion
Field treatment of ALTEs may be largely supportive. However, EMS should have a clear understanding that ALTEs can be a warning sign for more serious problems that can’t be addressed in the prehospital setting, but should be evaluated in a pediatric facility. This knowledge should lead EMS personnel to explain the importance of transporting to an appropriate medical facility for all ALTE patients.

Because EMS has the unique picture of the child’s home environment, the taking of a detailed history, and documentation of the child’s condition, as well as the environment, will assist the ED physician in determining the underlying cause of the ALTE, and lowering the risk of subsequent events.

References
1. National Institutes of Health Consensus Development Conference on Infantile Apnea and Home Monitoring, Sept. 29 to Oct. 1, 1986. Pediatrics. 1987;79(2):292—299.
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3. Hall K, Zalman B. Evaluation and management of apparent life-threatening events in children. Am Fam Physician. 2005;71(12):2301—2308.
4. Carolan P. (Feb. 7, 2013.) Apparent life threatening events. Medscape. Retrieved May 1, 2014, from http://emedicine.medscape.com/article/1418765.
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8. Samuels MP, Poets CF, Noyes JP, et al. Diagnosis and management after life threatening events in infants who received cardiopulmonary resuscitation. BMJ. 1993;306(6876):489—492.
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12. Kant S, Fisher JD, Nelson DG, et al. Mortality after discharge in clinically stable infants admitted with a first-time apparent life-threatening event. Am J Emerg Med. 2013;31(4):730—733.