. 2012 Jul 10;22(3):301–324. doi: 10.1016/j.thorsurg.2012.05.002

Table 4.

Initial empiric therapy for HAP, VAP, and HCAP in patients with late-onset disease or risk factors for multidrug-resistant pathogens and all disease severity

Potential Pathogens	Combination Antibiotic Therapy^a
Pathogens listed in Table 2 and MDR pathogens Pseudomonas aeruginosa Klebsiella pneumoniae (ESBL+)^b Acinetobacter spp^b MRSA Legionella pneumophila^b	Antipseudomonal cephalosporin (cefepime, ceftazidime) or Antipseudomonal carbapenem (imipenem or meropenem) or β-Lactam/β-lactamase inhibitor (piperacillin-tazobactam) plus Antipseudomonal fluoroquinolone^b (ciprofloxacin or levofloxacin) or Aminoglycoside (amikacin, gentamicin, or tobramycin) plus Linezolid or vancomycin^c

Abbreviation: ESBL, extended-spectrum β-lactamase.

Initial antibiotic therapy should be adjusted or streamlined based on microbiologic data and clinical response to therapy.

If an ESBL⁺ strain, such as K pneumoniae or an Acinetobacter sp is suspected, a carbapenem is a reliable choice. If L pneumophila is suspected, the combination antibiotic regimen should include a macrolide (eg, azithromycin) or a fluoroquinolone (eg, ciprofloxacin or levofloxacin) should be used rather than an aminoglycoside.

If MRSA risk factors are present or there is a high incidence locally.

Reprinted with permission of the American Thoracic Society. Copyright © 2012 American Thoracic Society. Guidelines for the management of adults with hospital-acquired, ventilator-associated, and healthcare-associated pneumonia. Am J Respir Crit Care Med 2005;171:388–416. Official journal of the American Thoracic Society.