From the Guidelines
Pseudomonas coverage should be added to community-acquired pneumonia (CAP) treatment in patients with severe disease, recent hospitalization, or other specific risk factors, as outlined in the 2019 American Thoracic Society and Infectious Diseases Society of America guidelines 1. When considering the addition of Pseudomonas coverage, the following risk factors should be taken into account:
- Recent hospitalization within 90 days
- Recent antibiotic use within the past 90 days
- Immunocompromised status
- Known prior respiratory colonization with Pseudomonas aeruginosa
- Structural lung disease, such as bronchiectasis or cystic fibrosis For empiric coverage, appropriate options include an antipseudomonal beta-lactam (piperacillin-tazobactam 4.5g IV q6h, cefepime 2g IV q8h, or meropenem 1g IV q8h) plus either a respiratory fluoroquinolone (levofloxacin 750mg IV/PO daily) or an aminoglycoside (such as tobramycin 5-7mg/kg IV daily) 1. The rationale for covering Pseudomonas in these specific scenarios is that standard CAP regimens lack activity against this organism, which is intrinsically resistant to many antibiotics and associated with higher mortality when treatment is delayed 1. Once Pseudomonas is confirmed, treatment should continue for at least 7 days, with longer durations considered for severe infections or immunocompromised hosts 1. It is essential to note that the 2019 guidelines provide the most recent and highest-quality evidence for the management of CAP, and therefore, should be prioritized in clinical decision-making 1.
From the Research
Pseudomonas Aeruginosa Coverage in Community-Acquired Pneumonia (CAP)
Risk Factors for Pseudomonas Aeruginosa
- Prior infection/colonisation due to P. aeruginosa 2
- Chronic lung diseases such as tracheostomy, bronchiectasis, and/or very severe chronic obstructive pulmonary disease (COPD) 2, 3
- Hospitalization in the past 12 months 3
- Dementia and cerebrovascular disease may also be associated with P. aeruginosa CAP, although the evidence is less clear 4
Empirical Antibiotic Therapy
- Empirical antibiotic therapy against P. aeruginosa within the first 48 hours of presentation is associated with lower 30-day mortality in patients with CAP due to P. aeruginosa 4
- The use of anti-pseudomonal antibiotics should be guided by the presence of risk factors, such as those listed above 2, 3
- A scoring system incorporating variables such as prior P. aeruginosa isolation or infection, hospitalization in the past 12 months, and bronchiectasis may be useful in guiding decision-making about empiric anti-pseudomonal antibiotic therapy 3
Treatment Recommendations
- For patients with CAP and risk factors for P. aeruginosa, a combination of piperacillin/tazobactam, cefepime, imipenem, or meropenem and levofloxacin or ciprofloxacin may be recommended 5
- Treatment duration of more than 7 days is not generally recommended, except for proven infections with P. aeruginosa, for which 15 days of treatment appears to be appropriate 5