A frequently used validated set of clinical stability criteria in patients with CAP and supported by the 2019 ATS/IDSA CAP guidelines consists of a temperature ≤37.8 ᵒC (100.0 ᵒF) AND no more than 1 CAP-related sign of clinical instability as listed below: 1-3
- Heart rate >100/min
- Systolic blood pressure <90 mm Hg
- Respiration rate >24 breaths/min
- Arterial oxygen saturation <90% or Pa02<60 mm Hg (room air)
Using these criteria, the risk of clinical deterioration serious enough to necessitate transfer to an intensive care unit may be 1% or less, 1 while failure to achieve clinical stability within 5 days is associated with higher mortality and worse clinical outcome. 2 The median time to clinical stability (as defined) for CAP treatment is 3 days.1
A 2016 randomized-controlled trial involving patients hospitalized with CAP found that implementation of above clinical stability criteria was associated with safe discontinuation of antibiotics after a minimum of 5 days of appropriate therapy. 3
Potential limitations of the above study include heavy use of quinolones (80%), underrepresentation of patients with severe CAP (Pneumonia Risk Index, PSI, V), and exclusion of nursing home residents, immunosuppressed patients, those with chest tube, or infection caused by less common organisms, such as Staphylococcus aureus or Pseudomonas aeruginosa.
Lack of clinical stability after 5 days of CAP treatment should prompt evaluation for complications of pneumonia (eg, empyema, lung abscess), infection due to organisms resistant to selected antibiotics, or an alternative source of infection/inflammatory/poor response. 2
References
- Halm, EA, Fine MJ, Marrie TJ, et al. Time to clinical stability in patients hospitalized with community-acquired pneumonia: implications for practice guidelines. JAMA 1998;279:279:1452-57. https://reference.medscape.com/medline/abstract/9600479
- Metlay JP, Waterer GW, Long AC, et al. Diagnosis and treatment of adults with community-acquired pneumonia. Am J Respir Crit Care Med 2019;200:e45-e67. https://www.ncbi.nlm.nih.gov/pubmed/31573350
- Uranga A, Espana PP, Bilbao A, et al. Duration of antibiotic treatment in community-acquired pneumonia. A multicenter randomized clinical trial. JAMA Intern Med 2016;176:1257-65. https://www.ncbi.nlm.nih.gov/pubmed/27455166/
