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 , 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 https://www.chop.edu/clinical- ... 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... 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... 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