Overview
Clinical Meaning
Antibiotic selection for respiratory infections requires understanding of the most likely pathogens based on clinical syndrome, patient factors, and local resistance patterns.
Antibiotic selection for respiratory infections requires understanding of the most likely pathogens based on clinical syndrome, patient factors, and local resistance patterns. CAP: S. pneumoniae (most common), H. influenzae, M. pneumoniae, C. pneumoniae, Legionella. AECOPD: H. influenzae, M. catarrhalis, S. pneumoniae. HAP/VAP: MRSA, P. aeruginosa, Klebsiella, Acinetobacter. The clinician must consider pharmacokinetic-pharmacodynamic (PK-PD) principles: beta-lactams are time-dependent (efficacy depends on time above MIC), aminoglycosides and fluoroquinolones are concentration-dependent (efficacy depends on Cmax/MIC ratio). Antibiotic stewardship principles include using the narrowest effective spectrum, shortest effective duration, de-escalation based on culture results, and avoiding unnecessary antibiotics for viral infections.