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A 46-year-old man is evaluated in the emergency department for fever and altered mental status. Five days ago he underwent replacement of a ventriculoperitoneal shunt used to manage congenital hydrocephalus. The procedure was unremarkable, and he did well postoperatively until the rapid onset of confusion and fever over the past several hours. Medical history is otherwise unremarkable, and he takes no medications.
On physical examination, the patient is confused and mildly agitated. Temperature is 39.7 °C (103.5 °F), blood pressure is 142/87 mm Hg, pulse rate is 110/min, and respiration rate is 16/min. The general medical examination shows healing surgical incisions on the scalp, neck, and upper abdomen that are clean and dry. Marked nuchal rigidity is noted.
Neurologic examination reveals altered sensorium but is otherwise nonfocal.
Head CT shows the ventriculoperitoneal shunt in proper position and no hydrocephalus or other focal lesions.
Laboratory evaluation of the cerebrospinal fluid shows a leukocyte count of 4660/μL (4660 × 106/L) with neutrophilic predominance, glucose level of 15 mg/dL (0.8 mmol/L), and protein level of 480 mg/dL (4800 mg/L). Gram stain and culture results are pending.
Which of the following is the most appropriate empiric antibiotic treatment?
a-Ampicillin, vancomycin, and ceftriaxone
b-Meropenem and vancomycin
c-Moxifloxacin
d-Vancomycin and ceftriaxone
Correct Answer: B
Educational Objective: Provide empiric antimicrobial therapy with meropenem and vancomycin for a patient with nosocomial bacterial meningitis.
Key Point
Empiric antimicrobial therapy for nosocomial meningitis must cover a broad spectrum of pathogens, including gram-negative organismsand Staphylococcus aureus, particularly methicillin-resistant S. aureus.This patient should begin empiric antimicrobial therapy with intravenous meropenem and vancomycin. He developed fever, nuchal rigidity, and altered mental status after a neurosurgical intervention, and analysis of the cerebrospinal fluid is consistent with bacterial meningitis following an invasive central nervous system (CNS) surgical procedure. In the setting of nosocomial meningitis, empiric antimicrobial therapy must cover a broad spectrum of pathogens, including gram-negative
organisms (including Pseudomonas aeruginosa, Acinetobacterspecies, and Enterobacteriaceae) and Staphylococcus aureus (including methicillin-resistant S. aureus [MRSA]). Meropenem, a monobactam, is a broad-spectrum, bactericidal β-lactam with excellent coverage of gram- positive and gram-negative organisms that effectively penetrates the CNS, making it an excellent agent for empiric treatment of nosocomial meningitis.