The initiation of antibiotic therapy is a common challenge for clinicians caring for hospitalized patients. Many factors influence the choice of whether to start antibiotics, when to start, and which agent or agents to employ. Often the decision to initiate antibiotics and to select appropriate antibiotic agents happens before confirmation of the presence of a treatable infection and before its precise location, severity, and specific infectious cause is identified. Some of the factors to consider include the likelihood of a treatable infection actually being present, the risks of an untreated infection, the odds of predicting the correct pathogen involved, the chances of resolution without antibiotic therapy, and the need to identify the organism definitively. Other antibiotic-related factors include the toxicity profile and the pharmacodynamic parameters of the drug.

This chapter provides guidance for antibiotic selection according to (1) common pediatric clinical syndromes (Table 94-1) and (2) specific bacteria pathogens (Table 94-2). Antibiotic susceptibilities of organisms vary by region, by hospital, and in some cases, units within a hospital. For proper treatment and appropriate use, the clinician must remain cognizant of these ever-changing antibiotic-susceptibility profiles by reviewing the current literature and antibiograms (local and hospital). Importantly, if culture and sensitivity results become available, the clinician should modify antibiotic coverage to the narrowest spectrum that effectively treats the relevant pathogen(s) and adequately targets the site of infection.