Suspicion of nosocomial pneumonia

Obtain lower respiratory tract sample for culture and microscopy (quantitative or semi-quantitative)

Clinical
Fever
Purulent tracheobronchial secretions
Declining oxygenation status

Laboratory
Increasing white cell count; worsening oxygenation

Radiographic
New or worsening infiltrates

End

Factors to consider prior to initiation of treatment

Risk factors for MDR pathogens
Underlying comorbidities/severity of illness
Local microbiological resistane patterns
Time of onset–early or late (>5 days)

Initiate empiric antibiotics

Evaluate culture and assess clinical response in 48-72 hours

Good response or pathogens identified
De-escalate; 7-8 days therapy if no MDR pathogens and reassess

Negative culture
Consider stopping treatment if findings resolved and clinical improvement

Nonresponders
Search for complications, other sites of infections, inadequate dosage of antibiotics, other pathogens

No risk factors for MDR pathogens, early-onset disease

Potential pathogens
Streptococcus pneumoniae
Hemophilus influenzae
Methicillin-sensitive Staphylococcus aureus
Antibiotic-sensitive enteric gram-negative bacilli

Escherichia coli
Klebsiella pneumoniae
Enterobacter species
Proteus species
Serratia marcescens

THERAPY
ceftriaxone, levofloxacin, moxifloxacin, ampicillin/sulbactam Or ertapenem

Late-onset disease, underlying comorbidities, or risk factors for MDR pathogens

Core pathogens + MDR pathogens

Pseudomonas aeruginosa
Klebsiella pneumoniae (ESBL)
MRSA
Acinetobacter species
Legionella species

THERAPY
Anti-pseudomonal cephalosporin (cefepime, ceftazidime) Or
Anti-pseudomonal carbepenem (imipenem or meropenem) Or
β-Lactam/β-lactamase inhibitor (piperacillin-tazobactam)
Plus
Anti-pseudomonal fluoroquinolone (ciprofloxacin or levofloxacin) Or
Aminoglycoside (amikacin, gentamicin, or tobramycin)
Plus (if MRSA suspected)
Linezolid or vancomycin