Pediatric emergency medicine trisk 364

Infectious diseases
Bacterial sepsis a
Meningitis a
Urinary tract infection a
Viral infections—enterovirus, respiratory syncytial virus, herpes simplex a
Pertussis
Congenital syphilis
Omphalitis
Cardiac disease
Congenital heart disease a
Supraventricular tachycardia a
Myocardial infarction (most commonly aberrant left coronary artery)
Pericarditis
Myocarditis
Kawasaki disease
Endocrine disorders
Congenital adrenal hyperplasia
Metabolic disorders
Hyponatremia, hypernatremia a
Cystic fibrosis
Inborn errors of metabolism, galactosemia
Hypoglycemia a
Drugs/toxins—aspirin, carbon monoxide
Renal disorders
Posterior urethral valves
Hematologic disorders
Severe anemia a
Methemoglobinemia
Kernicterus
Gastrointestinal disorders
Gastroenteritis with dehydration a

Pyloric stenosis a
Intussusception


Necrotizing enterocolitis
Appendicitis
Volvulus
Incarcerated hernia a
Hirschsprung enterocolitis
Neurologic disease
Infant botulism
Shunt obstruction, infection a
Child abuse—intracranial hemorrhage a
a Indicates

more common causes.

TABLE 73.2
MOST COMMON DISORDERS THAT MIMIC SEPSIS
Urinary tract infection
Viremia

Congestive heart failure
Gastroenteritis with dehydration

Pertussis causes coughing, apnea, seizures, and death during infancy. Parents
may report respiratory distress, cough, poor feeding, and vomiting. A careful
history may reveal that the vomiting is often posttussive. History of exposure to
pertussis may be lacking because the infant usually acquires the disease from
older children or adults who have only symptoms of a common upper respiratory

infection. Physical examination will distinguish the infection from sepsis if the
infant has a paroxysmal cough. The characteristic inspiratory “whoop” after a
coughing paroxysm (a hallmark in older patients) is uncommon in very young
infants. Auscultation of the chest is usually normal; tachypnea and cyanosis may
be present. The classic CBC finding of marked lymphocytosis is often absent in
infants with pertussis, and a chest radiograph may not show the typical “shaggy
right heart border” in this age group, though atelectasis or pneumonia may be
present. PCR technique can reliably identify the condition from nasopharyngeal
specimens, and nasopharyngeal culture for Bordetella pertussis is confirmatory.
Infants with congenital syphilis may present in the first 4 weeks of life with
extreme irritability, pallor, jaundice, hepatosplenomegaly, and edema. Pneumonia,
painful limbs, snuffles, and skin lesions are common. Consider this diagnosis if a
history of maternal infection is obtained or if the child has been chronically ill
prior to presentation. Radiographs of the infant’s long bones may reveal diffuse


periostitis of several bones, and serologic testing is needed to confirm the
diagnosis.

Cardiac Diseases (See Chapter 86 Cardiac Emergencies )
An infant with underlying congenital heart disease (CHD), including
ventriculoseptal defect, valvular insufficiency, valvular stenosis, hypoplastic left
heart syndrome (HLHS), or coarctation of the aorta, may present with shock or
congestive heart failure and clinical findings similar to those of an infant with
sepsis. Symptoms may include tachycardia, tachypnea, pallor, duskiness, or
mottling of the skin. Cyanosis may not be present based on the direction of
shunting and the patient’s hemoglobin level, which decreases physiologically to a
nadir at about 4 weeks of age. There may be sweating, decreased pulses, and
hypotension caused by poor perfusion. A chronic history of poor growth and poor
feeding may help differentiate heart disease from sepsis. The presence of a

cardiac murmur, a gallop rhythm, cyanosis unresponsive to 100% oxygen
administration, hepatomegaly, neck vein distention, or peripheral edema may lead
one to consider primary cardiac pathology. Intercostal retractions and rales,
rhonchi, or wheezing are nonspecific findings and may be present on chest
examination in either heart failure or pneumonia. HLHS or coarctation of the
aorta may present with shock toward the end of the first or second week of life as
the patent ductus arteriosus (PDA) closes. A difference between upper- and
lower-extremity blood pressures in a young baby suggests coarctation of the
aorta, though pulse differences may not be detected if cardiac output is
inadequate. Normal femoral pulses do not exclude a coarctation because the
widened PDA provides flow to the descending aorta. Check the dorsalis pedis or
tibialis posterior pulses; these are more sensitive for detecting coarctation or low
cardiac output.
A chest radiograph often shows cardiac enlargement and may show pulmonary
vascular engorgement or interstitial pulmonary edema rather than lobar infiltrates
(as in pneumonia). The electrocardiogram (ECG) may reveal abnormalities
including right-axis deviation with right atrial and ventricular enlargement in
HLHS, but can be nonspecific. An echocardiogram is usually required to define
anatomy and confirm specific diagnoses.
Rarely, an infant with anomalous or obstructed coronary arteries will develop
myocardial infarction and appear septic. These infants may have colicky
behavior, dyspnea, cyanosis, vomiting, pallor, and other signs of heart failure.
They usually have cardiomegaly on chest radiograph, and the ECG usually shows
T-wave inversion and deep Q waves in leads I and AVL. Echocardiogram or
cardiac catheterization is needed to confirm the diagnosis.


Certain arrhythmias may cause an infant to appear ill. Supraventricular
tachycardia (SVT) often presents with findings similar to those of a septic infant.
This arrhythmia may be idiopathic (50%), associated with CHD (20%), or related

to drugs, fever, or infection (20%). Young infants with SVT often go
unrecognized initially as they have only poor feeding, fussiness, and some rapid
breathing. They eventually develop congestive heart failure as the condition goes
untreated and may present with shock. Fever can precipitate the arrhythmia,
confusing the condition with sepsis, though the cardiac examination will reveal
such extreme tachycardia in the infant that the heart rate cannot be counted, often
exceeding 250 to 300 beats per minute. An ECG will show regular atrial and
ventricular beats with 1:1 conduction, although P waves appear different than
sinus P waves and may be difficult to see as they are often buried in the T waves.
A chest radiograph may show cardiomegaly and pulmonary congestion.
Additional cardiac pathologies to consider include pericarditis and
myocarditis. Pericarditis may be caused by bacterial organisms such as
Staphylococcus aureus; myocarditis usually results from viral infections such as
coxsackievirus B. These babies will appear critically ill with fever and grunting
respirations, but a complete physical examination may help the physician
distinguish these conditions from sepsis if signs of heart failure or unexplained
tachycardia are present. Pericarditis may produce neck vein distention, distant
heart sounds, and a friction rub if a significant pericardial effusion exists.
Physical findings with myocarditis may include muffled heart sounds (due to
ventricular dilatation), gallop rhythm, hepatosplenomegaly, and weak distal
pulses with poor perfusion. A chest radiograph in a patient with pericarditis will
show cardiomegaly and a suggestion of effusion. The ECG will show generalized
T-wave inversion and low-voltage QRS complexes if pericardial fluid is present,
and ST-T–wave abnormalities may be seen. The echocardiogram will confirm the
presence or absence of a pericardial effusion and poor ventricular function in the
case of viral myocarditis. Cardiac magnetic resonance will show inflammation,
edema, and scarring. Troponins can detect cardiac injury, and natriuretic peptides
can help differentiate cardiac from respiratory symptoms, and though nonspecific
may help in leading to a diagnosis of myocarditis.
Kawasaki disease with associated coronary artery aneurysms is very rare in

young infants but may present with cyanosis and shock. Usually, history reveals
prolonged and unexplained fever, rash, and mucous membrane inflammation.
Neonates with Kawasaki disease often have an atypical presentation and the
classic features found in older infants and children (e.g., swelling of hands and
feet, cracked red lips, scleral erythema) may be absent in young babies. A CBC