Pediatric emergency medicine trisk 633

lesions causing congestive heart failure. Skeletal abnormalities, hand and arm in
particular, can be associated with cardiac malformations. Distinguish cool mottled
distal extremities due to coarctation from cutis marmorata, a normal mottling in
infants that appears with exposure to cold. In many cases of cardiac disease, the
breath sounds will be normal and typical signs of respiratory distress absent.
However, infants with left-sided obstructive disease and total anomalous
pulmonary venous return can present with grunting, retractions, and tachypnea. In
either cardiac or respiratory distress there can be reduced oxygen saturations. A
hyperoxia test, using arterial blood gas analysis while 100% oxygen is supplied
at a bedside, can be performed to distinguish between cardiac and pulmonary
causes of cyanosis. The neonate with cyanotic heart disease has little response to
supplemental oxygen, whereas in pulmonary disease the increase in saturation
may be dramatic. In practice, an increase in PO2 to more than 220 mm Hg would
suggest respiratory disease; 100 to 220 mm Hg would require evaluation for
cyanotic CHD; less than 100 mm Hg would suggest cyanotic CHD, and marked
cyanosis less than 40 to 50 mm Hg would be likely to have a poor mixing disease
such as transposition of the great arteries. If the hyperoxia test reveals positive or
borderline results, immediate further evaluation for cyanotic CHD by the
pediatric cardiologist is needed.
Chest radiographs should be obtained to rule out pulmonary disease as well as
to evaluate for pulmonary vascular markings, cardiomegaly, and characteristic
features found with some CHD—as in a “boot-shaped heart” seen with tetralogy
of Fallot (TOF). The assessment of cardiomegaly requires both an AP and lateral
chest radiograph and adequate inflation of the lungs. Electrocardiogram (ECG)
and echocardiogram should be obtained. Because sepsis and myocarditis are on
the differential of neonates presenting with symptoms of CHD, CBC, blood
culture, urinalysis, and urine culture should be obtained. Consider lumbar
puncture in light of clinical examination and history and the overall stability of
the patient.
Management
Airway management is always of primary concern. If the neonate is in respiratory

distress, establish a secure airway and maintain adequate oxygenation. Intubation
with sedation and paralysis may reduce cardiac demand significantly. Neonates
with hypotension require fluid and resuscitation and possibly inotropic support
with dopamine or dobutamine. Neonates with strong clinical suspicion for ductaldependent CHD should receive prostaglandin E1 (PGE1 ) infusion in advance of a
definitive diagnosis. PGE1 is the standard medical intervention in neonate with


duct-dependent lesions. PGE1 relaxes the ductus and allows ongoing critical
shunting of blood from left to right or right to left, depending on the cardiac
lesion. The initial intravenous dose of PGE1 is 0.01 mcg/kg/min in neonates with
echocardiographic confirmation of a large patent DA to prevent closure and
maintain ductal patency. If the size of ductus is unknown or the ductus is
restrictive, the starting dose is 0.05 mcg/kg/min. If no improvement, the dose can
be increased incrementally to a maximum of 0.1 mcg/kg/min. After the infant’s
condition has stabilized, the usual maintenance dose is 0.025 mcg/kg/min. Apnea,
bradycardia, hypotension, fluid–electrolyte imbalances, irritability, fever, and
cutaneous flushing are potential complicating side effects of PGE1 . The
physician should have all intubation equipment readily available because apnea
can occur at any time during infusion. A second intravenous catheter should also
be in place to provide resuscitative fluids as necessary. Consult immediately with
a cardiovascular specialist and transfer to a facility with pediatric cardiac
expertise.

NEONATAL RESPIRATORY AND AIRWAY PROBLEMS
Goals of Emergency Care
Acute airway obstructions and respiratory distress in neonates can cause swift
respiratory deterioration. The neonatal airway has distinct features that predispose
it to occlusion more frequently than children and adults. Additionally, neonates
have very low respiratory reserve (e.g., intubation attempt should only be
attempted for 30 seconds before cardiovascular instability ensues) and high

metabolic demands. Rapid evaluation and diagnosis of acute life-threatening
conditions necessitates an understanding of the different etiologies and coexisting
medical problems. Respiratory distress caused by nonrespiratory causes (such as
cardiac lesions, metabolic acidosis, and neonatal sepsis) should be differentiated
from those caused by airway and lower respiratory disease. Stabilization of the
airway and breathing is a priority. There should be appropriate equipment and
experienced personnel capable of urgently establishing an airway in a neonate.
Treatment is aimed at rapid recognition to prevent secondary morbidity.
KEY POINTS


Neonates with respiratory distress or stridor can deteriorate very
rapidly. Always triage urgently.
Premature infants with bronchopulmonary dysplasia who develop acute
respiratory distress will need admission.
Intubation attempts in a newborn should be limited to 30 seconds to
prevent iatrogenic complications.
RELATED CHAPTERS
Signs and Symptoms
Apnea: Chapter 14
Cyanosis: Chapter 21
Respiratory Distress: Chapter 71
Septic-Appearing Infant: Chapter 73
Stridor: Chapter 75
Medical, Surgical, and Trauma Emergencies
Cardiac Emergencies: Chapter 86
Infectious Disease Emergencies: Chapter 94
Pulmonary Emergencies: Chapter 99

Diseases That Cause Stridor in a Neonate

Goals of Treatment
Stridor is the most common symptom of congenital anomalies of the airway in a
neonate. Clinicians need to rapidly identify conditions that are life threatening
and differentiate them from benign etiologies. The primary goal should be quick
triage and stabilization.
Supraglottic lesions (e.g., laryngomalacia) usually present with coarse
inspiratory stridor whereas tracheal lesions (e.g., tracheomalacia and vascular
rings) may present with expiratory stridor or wheezing. Infants with glottic or
subglottic lesions (e.g., vocal cord paralysis, papillomas, laryngeal web,
subglottic hemangiomas, and subglottic stenosis) can have a biphasic musical
type of stridor. These sounds of stridor can be difficult to differentiate clinically.
Other symptoms such as cough, cyanosis, and feeding difficulties should also be
elicited in the history. All neonates with stridor should be assessed for a stable
airway, signs of respiratory distress (tachypnea, tachycardia, retractions, cyanosis,


and agitation), CO2 retention or aspiration, and placed on continuous pulse
oximetry and oxygen to maintain saturations above 95%. Blood gas to assess
ventilation should also be considered. Those with significant stridor may need
respiratory support (high-flow humidified nasal cannula, continuous positive
airway pressure [CPAP], or intubation and mechanical ventilation). If the airway
is unstable, there should be appropriate equipment and personnel experienced in
management of a neonatal airway.
The neonatal larynx has multiple features that are different from that of older
children. These predispose neonates to very rapid deterioration in respiratory
status and can make endotracheal intubation challenging. In addition to the
smaller size, less than one-third of the adult size larynx, the position of the larynx
at birth is higher (C4 rather than C7 in children). The epiglottis is longer and
omega shaped. Lastly, the cartilage is softer than that of older children, which is
thought to contribute to the collapsibility of the laryngeal airway. Additionally,

neonates have very low respiratory reserve and high vagal tone; each intubation
attempt should be preceded by preoxygenation and should not last longer than 30
seconds. Vagolytics such as atropine should be given prior to intubation to
prevent reflex bradycardia and promote cardiac stability. Obtaining an airway
film may help in differentiating etiology (e.g., subglottic stenosis, retropharyngeal
abscess, soft tissue tumors compressing airway, or congenital cysts). A chest
radiograph may also help if there is a suspected pulmonary component. Obtaining
a blood gas (if possible) helps with assessment of hypoxia and carbon dioxide
retention. All newborns with respiratory instability should be admitted to an
intensive care unit. In newborns with significant airway anomalies, surgical
consultation is indicated. Chapter 75 Stridor , further discusses the diagnosis and
management of children with stridor.
CLINICAL PEARLS AND PITFALLS