Things We Do for No Reason – The “48 Hour Rule-out” for Well-Appearing Febrile Infants
Carrie Herzke, MD, Department of Pediatrics and Medicine, Johns Hopkins School of Medicine, 600 N. Wolfe Street, Meyer 8-134, Baltimore, MD 21287; Telephone: 443-287-3631, Fax: 410-502-0923 E-mail: email@example.com
Fever, defined as a rectal temperature of ≥38°C (100.4°F), is a common reason for hospital admission of infants aged ≤ 90 days. Febrile infants are often admitted to the hospital due to risk for serious bacterial infections, such as urinary tract infection, bacteremia, and meningitis. The traditional observation time is 48 hours following the collection of blood, urine, and cerebrospinal fluid cultures. In the majority of these infants, bacterial infection is not the source of fever. When a bacterial source is identified, less than 0.3% of the bacteria will be detected more than 24 hours after the cultures were obtained in low-risk infants.1 Recent studies show that the traditional 48 hour hospital observation period is unnecessary for infants aged ≤ 90 days who are at low risk for serious bacterial infection based on available scoring systems.