A 45-year-old woman is undergoing chemotherapy for breast cancer. She presents 10 days after her last chemotherapy with fever (temperature >38.5), but no other symptoms except a sore throat and mouth. On examination, she looks well, there is oral mucositis, ears are normal, lungs are clear, and the central line site is clean. The CXR, urinalysis, and biochemistry are normal. Her WBC is 800/mL and the absolute neutrophil count is low (<500). Which of the following is the most appropriate next step in management?

Several antibiotic combinations could be used and may vary with the indigenous organisms. Aminoglycoside and cephalosporin are commonly used in combination. The antibiotic combination must cover both Gram-positive and Gram-negative organisms. Antifungal or viral agents are not empirically started unless there is an appropriate clinical fungal or viral infection. In some centers, empiric antifungal agents are started if the patient remains febrile on antibiotics after 5 days. Observation alone is not an option, since these individuals usually have some form of bacteremia causing the fever.