Treatment of Multifocal Pneumonia

Initial Assessment and Risk Stratification

The Infectious Diseases Society of America recommends that if the patient developed pneumonia ≥48 hours after hospital admission, treat as hospital-acquired pneumonia (HAP) 1.
The British Thoracic Society suggests that if symptoms began in the community or within 48 hours of admission, treat as community-acquired pneumonia (CAP) 2.
The Infectious Diseases Society of America states that an 80-year-old patient is at inherently higher mortality risk due to age alone and should be assessed for high-risk features including need for ventilatory support, septic shock, or recent IV antibiotic use within 90 days 1, 3.

The British Thoracic Society recommends combined oral therapy with amoxicillin plus a macrolide (erythromycin or clarithromycin) as the preferred empiric regimen for elderly patients requiring hospital admission 2, 4.
The British Thoracic Society suggests that most hospitalized elderly patients can be adequately treated with oral antibiotics 2, 5.
The British Thoracic Society recommends that when oral treatment is contraindicated, use IV ampicillin or benzylpenicillin together with IV erythromycin or clarithromycin 2, 6.
The British Thoracic Society states that levofloxacin 750 mg IV/PO daily is an alternative for patients intolerant of penicillins or macrolides 2, 7.

The British Thoracic Society recommends that patients with severe pneumonia require immediate parenteral antibiotics upon diagnosis 8, 6.
The British Thoracic Society suggests that the preferred regimen is IV co-amoxiclav OR a 2nd/3rd generation cephalosporin (cefuroxime, cefotaxime, or ceftriaxone) PLUS a macrolide (clarithromycin or erythromycin) 8, 9, 7.
The British Thoracic Society recommends a treatment duration of 10 days for microbiologically undefined severe pneumonia 6, 7.
The British Thoracic Society suggests extending treatment to 14-21 days if Legionella, Staphylococcus aureus, or Gram-negative enteric bacilli are suspected or confirmed 6, 7.

The Infectious Diseases Society of America recommends that the treatment algorithm depends on mortality risk and MRSA risk factors 1, 3, 10.
The Infectious Diseases Society of America states that MRSA coverage is indicated if ANY of the following are present: IV antibiotic use within the prior 90 days, treatment in a unit where MRSA prevalence among S. aureus isolates is >20% or unknown, or high risk of mortality (need for ventilatory support or septic shock) 1, 3.
The Infectious Diseases Society of America recommends using TWO antipseudomonal agents from different classes (avoid combining two β-lactams) PLUS vancomycin or linezolid for MRSA coverage 1, 3, 10.
The Infectious Diseases Society of America suggests using a single antipseudomonal agent with MSSA coverage for patients NOT at high risk without MRSA risk factors 1, 10.
The Infectious Diseases Society of America recommends basing empiric therapy on local antibiograms whenever possible, particularly for HAP where institutional resistance patterns vary significantly 1.