ICU · Infectious Diseases

Acute severe pneumonia: bacteraemia and metastatic infection

Also known as Bacteraemic pneumonia · Metastatic infection from pneumonia · Endocarditis from bacteraemia · Septic emboli

Bacteraemia complicates 10-25% of CAP cases and significantly increases mortality (2-3x). Most common organisms causing bacteraemia: S. pneumoniae (1, 60-70%), S. aureus (including MRSA — highest metastatic risk), Haemophilus influenzae. Bacteraemia enables metastatic seeding to distant sites: endocarditis (25% of S. aureus bacteraemia), meningitis, vertebral osteomyelitis, septic arthritis, psoas abscess, splenic abscess. Management: prolonged antibiotic course (14 days minimum for S. aureus bacteraemia), repeat blood cultures until negative, search for metastatic foci (echocardiogram, imaging), source control if identified. Persistent bacteraemia 72h despite appropriate antibiotics: search for deep focus.