Transcript An Apparent Life-Threatening Event (ALTE) is an episode

My Baby Turned Blue!
What Direction To Take
Chris Landon MD FAAP, FCCP
Director of Pediatrics
Ventura County Medical Center
An Apparent Life-Threatening Event
(ALTE) is an episode that frightens a
child’s caretaker. These events can
involve any of the following:
 Apnea
 Color change (cyanosis, pallor, erythema,
plethora)
 Marked change in muscle tone (limpness)
 Choking or gagging
These events usually occur in
infants less than 12 months old, but
ALTE should be suspected in any
child less than 2 years of age who
displays these symptoms.
Most patients will appear stable
and may have a normal physical
exam by the time field personnel
arrive. Despite their appearance,
some of these patients will be later
diagnosed with conditions that
may require further medical care.
PURPOSE
 To increase awareness of the risks of
Apparent Life-Threatening Events, and to
encourage the transport of patients who
have suffered symptoms of an ALTE.
TREATMENT
 Provide routine pediatric medical care.
 Assume the history given is accurate.
 Obtain a description of the severity, nature,
and duration of the event.
Any known chronic illnesses?
Evidence of seizure activity?
Current or recent infections?
History of gastroesophageal reflux (spitting, vomiting)?
Inappropriate mixture of formula?
History or evidence of recent trauma?
Medications? (current and recent), including over the
counter drugs
Associated events (eating, crying, etc.)
Complete a comprehensive physical exam. Include
evaluation of the child’s appearance, skin color, and
interaction with the environment and parents.
Check for any evidence of trauma.
Treat any identifiable injuries/illnesses.
Transport.
 If the parent or guardian refuses medical
care and/or transportation, make base
contact with the Base Hospital Physician
prior to completing an AMA form and
leaving the scene.
Background:
Infant apnea, more appropriately called an apparent
life-threatening event (ALTE), was defined by the
1986 National Institutes of Heath Consensus
Development Conference on Infantile Apnea and
Home Monitoring as follows: "An episode that is
frightening to the observer and is characterized by
some combination of apnea (central 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 fears that the infant has
died. Previously used terminology, such as "aborted
crib death" or "near miss SIDS" should be
abandoned as it implies a, possibly, misleading close
association between this type of spell and SIDS.
This definition encompasses a broad range of
behaviors and potential diagnoses. In most cases, the
emergency physician will be examining a wellappearing infant who has experienced an ALTE
prior to arrival at the ED or an infant who has home
apnea and bradycardia monitoring with a history of
frequent monitor alarms. The challenge lies in using
the history provided by the caretakers to make a
presumptive diagnosis and an appropriate referral.
Pathophysiology: ALTE is not so much a
specific diagnosis as a description of an
event.
There are several potential causes for such an event. These
include central apnea, obstructive apnea,
gastroesophageal reflux (GER), cardiac arrhythmia and
seizure disorder. ALTE is also a common complaint for
parents who are perpetrators of Munchausen's syndrome
by proxy and may be a secondary manifestation of
certain types of child abuse. Apnea may be a part of the
presentation of infants with sepsis and other severe
illnesses. However, these infants will not be well
appearing and a discussion of the management of such
patients will be reviewed at a later lecture.
The cause of central apnea is unclear. Certain drugs
are known to cause central apnea but, in most cases,
there is no history of drug exposure. It is important
for the examining physician to ask about maternal
illicit drug use, particularly when the infant is breastfed or when smokeable substances are possibly being
used. Carbon monoxide poisoning must be
considered, as young infants are more likely to be
affected than adults are due to fetal hemoglobins.
The usual cause of central apnea is often presumed
to be immaturity of the respiratory center, with a
weaker respiratory response to hypercapnia.
Studies of patients followed in apnea centers have
shown increased respiratory pauses compared to
age-matched controls. However, there appears to
be no correlation between these events and lower
levels of oxygen. Studies of hypercapnia in infants
with known apnea have failed to demonstrate an
abnormal response to CO2.
Obstructive apnea may occur for several reasons.
Some infants have laryngomalacia or
tracheomalacia. In these cases a thin, floppy upper
airway and trachea, which is prone to collapse
during the negative pressure of inspiration. Such
infants are prone to stridorous breathing.
Obstructive apnea may also occur as a result of
gastroesophageal reflux (GER). Although apnea from
GER usually has another cause, in some cases, GER
causes laryngospasm and obstructive apnea. Infants
with severe GER may have apnea due to stimulation
of chemoreceptors around the larynx. This results in
central apnea, bradycardia and pallor. In older
patients with GER, ALTE is more likely to result from
laryngospasm.
Cardiac arrhythmias cause ALTEs for obvious
reasons. Infants with prior cardiac surgery or
known congenital defects in the vicinity of the
conducting system are possible victims but, in
most cases, the causes for the arrhythmia are
obscure. The infant with a cardiac cause for
ALTE is less likely to present with primary apnea.
Neonatal seizures are often quite different from
those seen in older children. While apnea may
result from seizures, it is usually not the only
symptom. Most patients with seizures also have
abnormal movements or posturing, and
lateralizing eye movements.
Apnea and ALTE are also seen as a result of child
abuse and should be considered in cases of infants
who are not well appearing on arrival.
Munchausen's syndrome by proxy may be
suspected in the infant who has recurrent or
bizarre ALTEs, particularly when the family has
been to several EDs and physicians with the same
complaint and "no one can find the cause". A
previous SIDS death in the same family also
increases the risk of Munchausen's by proxy.
Frequency:
 In the US: Estimates of the incidence of ALTE range
from 0.5-6% in the general population. However, the
studies upon which these estimates are based have
methodological flaws, which make them hard to
interpret.
 Internationally: The worldwide incidence of ALTE is
unknown. One report from Sweden places the incidence
of apnea during the first 4 d of life at 0.35/1,000
population.
Mortality/Morbidity:
 There are studies that suggest 5-10% of victims of SIDS
have had a previous ALTE. Eight studies of mortality
among patients with a history of ALTE place the death
rate at 1% with some, but not all, patients dying of SIDS.
On the other hand, it is well recognized that most victims
of SIDS have not had a prior ALTE.
Sex:
Data on this subject are variable but most studies
demonstrate a male predominance. In some studies
the male to female ratio among infants with ALTE
is as high as 2:1.
Age:
The average infant presenting after an ALTE is
8-14 wk. About 7% of these infants were born
prematurely.
History:
In most cases, the child will have been seen to change colors
and/or stop breathing or will have been found limp by the
caretakers. Additionally, he/she may have experienced a
significant episode of coughing, choking, or gagging.
Physical:
In the vast majority of cases, the infant appears
well and the examination will be entirely normal.
Infants who are not well appearing may have a
variety of serious disorders (see Differential
Diagnosis, below) so it is most important to
identify infants who look sick.
Causes:
 Bacteremia and Sepsis
Bronchiolitis
Sudden Infant Death Syndrome
Other Problems to be Considered:
Well Child, Anxious Mother (diagnosis of exclusion)
Child Abuse (Munchausen's by proxy)
Status Epilepticus and Seizure Disorders
Dysrhythmias
Cardiac Congenital Malformations
If the infant is truly well afebrile and well appearing, laboratory studies
are likely to be normal.
If the infant is not well appearing or if assessment is impossible due to
age, the following studies should be considered:
Complete blood count (CBC) with differential
Electrolytes
Lumbar puncture
Urinalysis
These tests will identify the presence of an unexplained metabolic acidosis
and help to identify the potentially septic infant or the infant with
unexplained anemia.
Additionally, the combination of hyperkalemia and hyponatremia may be
the first suggestion of congenital adrenal hyperplasia in the male
infant.
When the clinical presentation warrants, a carboxyhemoglobin level,
methemoglobin level and a screen for certain toxins (e.g., cocaine)
should be considered.
If the infant has a history of central apnea, he/she may be on theophylline
or caffeine, which stimulates the central respiratory centers.
Therefore, levels of these drugs to document therapeutic levels and/or
compliance, may be helpful.
Imaging Studies:
In most cases no imaging studies are needed.
In those cases where raised intracranial pressure or
intracranial hemorrhage is suspected a heed CT scan is
indicated.
In premature infants a head CT scan may reveal
intraventricular and periventricular hemorrhages.
When child abuse is being seriously considered, a skeletal
survey should be obtained. Other Studies: A neurologists
may request admission for an EEG.
Prehospital Care:
Prehospital care of the infant with an ALTE
includes resuscitation, if necessary, and
monitored transport to an ED.
If the infant has an apneic event during transport,
prehospital personnel should first attempt simple
manual stimulation of the infant.
Brisk rubbing along the back, patting and
thumping the feet may be tried.
If these maneuvers fail, artificial ventilation should
be initiated.
Emergency Department Care:
In the ED, all infants who have sustained an ALTE should
have cardiac and respiratory monitoring.
Ill-appearing infants should be treated as needed based
upon their clinical condition.
This may include resuscitation or treatment of sepsis.
Well-appearing infants may need no emergency treatment
other than a careful history and physical examination.
Consultations:
Consultation is most important for those patients
who are on home monitoring. Most of these
children are followed by a special apnea service.
Such services may be helpful by providing
important historical data about the patient. Also,
they often facilitate contact with the company
providing the monitoring service.
Additionally, the apnea service may be able to
simplify the process of admission or transfer to a
tertiary care pediatric facility.
Further Inpatient Care:
Most children who have sustained an ALTE should be
admitted for treatment of their underlying medical
problem, or for a diagnostic evaluation.
The diagnostic evaluation of the child with ALTE usually
includes a multichannel study.
The infant is observed for an extended period of time while
monitors record data (e.g., EEG, ECG, esophageal pH
probe, chest movement monitor and a nasal airflow
monitor).
Such monitoring requires some expertise and is probably
best conducted in a pediatric center.
Outpatient Care
There are 3 types of children who may be safely
discharged for further outpatient management.
If the history suggests that the family misinterpreted a
normal episode of periodic breathing
The infant/child is well appearing in the ED
If the infant had no color change and is not seen to have
frequent episodes of periodic breathing during a
reasonable period of monitored observation
Similarly, if the history suggests an isolated choking
episode in an infant who feeds aggressively, the child
may be discharged. The parents of such children
should be instructed to interrupt feeding more
frequently and to burp their infant often.
Outpatient Care
Finally, those infants already on a home monitor may
be discharged with the following provisions:
The infant is well appearing.
The problem is unequivocally related to the monitor.
The monitor problem can be corrected or the monitor
can be replaced.
Transfer:
Most infants who have an ALTE should be evaluated in a
facility with expertise in the diagnostic evaluation of such
patients.
The team transporting the infant should be capable of
monitoring and, if necessary, resuscitating an infant. If
available, a pediatric transport team is an excellent
choice.
The relationship between ALTE and SIDS is unknown.
Certainly, some infants who have ALTEs would have died
had they not been found in time.
One complication, which is often ignored, is the
psychological impact of home monitoring upon the family.
Monitoring places a tremendous amount of pressure on the
caretakers. Families deal with these pressures in many
ways.
Some parents eventually stop using the monitor while others
become dependent upon it.
Some families experience renewed fears when they are told
that their child no longer requires home monitoring.
Many of these stressors may be manifested in the ED.
It is not hard to imagine the parents of a child about to have
his/her home monitor discontinued presenting to the ED
with a complaint of frequent alarms in hope of having the
period of monitoring continued.
Prognosis:
Most children who survive an ALTE and are placed on
home monitoring do well.
In general, as the child matures, the cause of the ALTE is
diagnosed and treated or spontaneously resolves.
Patient Education:
Parents of infants who are discharged should be
instructed to return if:
more episodes occur,
episodes become associated with color change, or
new and/or worrisome findings (such as fever,
lethargy, or frequent vomiting) develop.
Infants who have had a choking episode should
receive feeding instructions as described above.
Families of monitored infants should be reminded
to maintain current CPR training.
From a Medical-Legal Standpoint
It is far better to err on the side of admission of most
of these infants.
Even though the baby is well appearing at the time
of ED evaluation, he or she may have had a
significant episode.
Only those infants who have had a single episode of
periodic breathing not associated with color
change, an isolated and explainable choking
episode or an unequivocal mechanical problem
with a home monitoring device, should be
considered candidates for discharge.
All patients discharged from the ED should have strict
instructions to return if the infant's condition worsens.
For example, 1 episode of periodic breathing is
acceptable, 10 episodes are not.
All infants presenting for ALTEs should be monitored
while in the ED.
Should transport be necessary, monitoring is also
required.
Additionally, all infants transported for the evaluation
and treatment of ALTEs should be transported by a team
capable of resuscitating an infant.
It is the responsibility of the referring institution to insure
an appropriate method of transport.
Special Concerns: Cyanotic Heart
Disease
Tetralogy of Fallot
Transposition of the great vessels
Truncus arteriosus
Total anomalous pulmonary venous return
CME Question 1: A well-appearing infant is brought to
the emergency department by his/her parents. The
parents state that the child "turned blue". All
EXCEPT which one of the following are likely
diagnoses?
A: Central apnea
B: Overwhelming sepsis
C: Cardiac arrhythmia
D: Gastroesophageal reflux
E: Seizure disorder
The correct answer is B: The other 4 conditions that
are listed may cause a well-appearing infant to have
an ALTE. The infant with sepsis is unlikely to be well
appearing.
CME Question 2: More unusual causes of an apparent
life-threatening event (ALTE) include all of the
following EXCEPT?
A: Munchausen's syndrome by proxy
B: Carbon monoxide poisoning
C: Inhalation of smokeable drugs of abuse
D: Central (idiopathic) apnea
E: Ingestion of toxins
The correct answer is D: Central apnea, sometimes
called idiopathic central apnea, is a common cause of
ALTE. The other entities are much less common.
Pearl Question 1 (T/F): A mother was holding her 6month-old male child when he suddenly assumed a
strange posture. The mother reports that he had
stiffening and extension of his right arm and that
his head turned to the right. This was associated
with a "blue spell." The most likely cause is
gastroesophageal reflux.
The correct answer is False: Seizures would be the
most likely cause of an ALTE associated with an
unusual posture or abnormal movements.
Pearl Question 2 (T/F): The relationship of ALTE
to sudden infant death syndrome is well
understood?
The correct answer is False: The relationship is
unknown. Only a fraction of the infants
diagnosed with ALTEs go on to die of SIDS.
Pearl Question 3 (T/F): A careful history will often
reveal the cause of ALTE.
The correct answer is True: A careful medical
history is the best way to make a presumptive
diagnosis. Sophisticated (and expensive) testing
can be employed judiciously when the examining
physician has done a good history.
Pearl Question 4 (T/F): A newborn infant is
brought into the Emergency Department because
he "stopped breathing." During your physical
examination, the mother screams "Oh my God,
he's doing it again." You note no color change.
The episode lasts 8 seconds (by your watch) after
which normal breathing resumes. The most likely
diagnosis is a normal respiratory pause.
The correct answer is True: The most likely
diagnosis is normal periodic breathing. Normal
infants have respiratory pauses lasting up to 20
seconds. These are nothing to be alarmed about
unless they are very frequent or prolonged.