Pediatric emergency medicine trisk 367

TABLE 73.3
APPROACH TO THE SEPTIC-APPEARING INFANT WITH
CHARACTERISTIC PHYSICAL FINDINGS


Physical findings

Diagnoses to consider

Specific tests

Cardiovascular
abnormalities

Congenital heart disease

Echocardiogram, ECG

Kawasaki disease

ECG, erythrocyte
sedimentation rate
Supraventricular tachycardia ECG
Myocarditis
Echocardiogram, ECG,
troponin, cardiac MRI
Myocardial infarction
ECG, cardiac MRI, troponin
Methemoglobinemia
Pao2 methemoglobin level
Neurologic

abnormalities

Meningitis

Lumbar puncture

Infant botulism
Child abuse

Stool for toxin identification
Long bone films, CT scan,
or MRI
CT scan, or MRI
Long bone films, CT scan,
or MRI
Coagulation profile
PCR, electroencephalogram,
CT scan, or MRI
Blood for 17hydroxyprogesterone,
renin, aldosterone,
cortisol
PCR

Shunt malfunction
Skin abnormalities Child abuse
Coagulopathy
Herpes simplex
Genitalia
abnormalities

Congenital adrenal
hyperplasia

Pulmonary
abnormalities

Pertussis
Pneumonia
Bronchiolitis

Renal
abnormalities

Metabolic acidosis
Posterior urethral valves

Chest radiograph
Respiratory syncytial virus
tests
Arterial blood gas
Abdominal, renal
ultrasound, voiding


(abdominal
mass)

cystourethrogram
Blood urea nitrogen,
creatinine

CT and MRI refer to intracranial imaging in this table.
ECG, electrocardiogram; CT, computed tomography; MRI, magnetic resonance imaging; PCR, polymerase
chain reaction.

Obtain a complete history including any previous medical problems such as
known heart disease or failure to thrive. Determine the time of onset of
symptoms, exposure to infection, medications given at home, and specific
symptoms noted by the parents. Next, perform a careful physical examination
because specific findings may lead to a diagnosis other than sepsis ( Table 73.3 ).
Follow with laboratory evaluation as indicated by findings on history and
physical examination. Promptly obtain a rapid test for blood sugar as
abnormalities may be life-threatening. For all sick infants, obtain a blood culture
and a urine culture, by either urethral catheter or suprapubic bladder tap. Perform
a lumbar puncture unless physical findings point strongly to a diagnosis other
than sepsis or the infant is too critically ill to tolerate the procedure (e.g.,
respiratory distress). Bruising or bleeding with intravenous access attempts
suggests the possibility of DIC and is a contraindication for lumbar puncture. If
available, send a CSF panel to rapidly detect pathogens associated with
meningitis and encephalitis by PCR. A chest radiograph is also essential to look
for pulmonary infection and to evaluate the heart size. Obtain a CBC as
leukocytosis will add support to a suspicion of sepsis and may also be found in
various other disorders including viral infections, myocarditis, pericarditis,
intracranial bleeds, NEC, appendicitis, intussusception, and methemoglobinemia.
For all sick infants, send studies to evaluate serum sodium, potassium, chloride,
glucose, and bicarbonate level, as metabolic problems (disturbances in acid–base
balance, electrolytes, blood sugar) can result from sepsis or be the primary
problem that mimics sepsis. If hyponatremia is found, consider water
intoxication, aspirin toxicity, cystic fibrosis, and CAH. If there is also a marked
hyperkalemia, CAH is most likely. If there is hypochloremic alkalosis or alkalosis

alone, then consider pyloric stenosis, aspirin toxicity, or gastroenteritis.
Hypoglycemia may be secondary to poor glucose reserves in an ill infant or
related to drug (aspirin) toxicity, inborn errors of metabolism, CAH, or
methemoglobinemia. The presence of acidosis could be due to poor perfusion
caused by shock, as well as primary problems such as dehydration, drug toxicity,
methemoglobinemia, appendicitis, CAH, and inborn errors of metabolism. In


addition to sending bacterial culture and starting broad-spectrum antibiotics,
consider stool and CSF isolates for viruses.
If the physical examination suggests a specific problem, it may be necessary to
obtain additional tests ( Table 73.3 ). Pallor, cyanosis, or cardiac abnormality
(muffled heart sounds, murmur, unexplained tachycardia, or arrhythmia) raises
concern for various cardiac disorders or methemoglobinemia. An ECG, arterial
blood to measure PaO 2 , and possibly an echocardiogram should then be
obtained. Unusual neurologic findings, such as a bulging fontanel, warrant a
lumbar puncture and previously mentioned blood studies to rule out meningitis. A
seizure should prompt a CT scan, EEG, and culture and treatment for herpes
simplex infection. Retinal hemorrhages may suggest an intracranial bleed and,
thus, a noncontrast CT scan, MRI, and lumbar puncture would be valuable
studies. Likewise, abdominal distention, rigidity, mass, or bloody stools indicate a
gastrointestinal emergency. In such cases, abdominal radiographs, ultrasound, or
air-contrast studies are important diagnostic aids in addition to a sepsis workup.
If the physical examination reveals bruises or purpura, evaluate for child abuse,
coagulopathy, and sepsis. Obtain long bone radiographs, coagulation profile
(including platelet count). If vesicular lesions are seen on the skin, obtain a PCR
and culture for herpes. If ambiguous genitalia are noted, send blood for 17hydroxyprogesterone, renin, aldosterone, and cortisol levels to rule out CAH (see
Chapter 89 Endocrine Emergencies ). Finally, if wheezing is detected on chest
examination, consider a nasopharyngeal swab for rapid detection of RSV and
consider a chest radiograph.

Suggested Readings and Key References
Sepsis
Gomez B, Mintegi S, Bressan S, et al. Validation of the “Step-by-Step” approach
in the management of young febrile infants. Pediatrics 2016;138:e20154381.
Kuppermann N, Dayan PS, Levine DA, et al. A clinical prediction rule to identify
febrile infants 60 days and younger at low risk for serious bacterial infections.
JAMA Pediatr 2019;173:342–351.
Polin RA; Committee on Fetus and Newborn. Management of neonates with
suspected or proven early onset bacterial sepsis. Pediatrics 2012;129:1006–
1015.
Scarfone R, Gala P, Murray A, et al. ED clinical pathway for evaluation/treatment
of febrile young infants (0-56 Days Old). The Children’s Hospital of
Philadelphia. 2010. Available online at />