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-