Assessment of severity in patients with community-acquired pneumonia: reply to letter by Challen et al.

Abstract

Sir: We agree with Challen et al. about the convenience of incorporating co-morbidities [1] or pulse oximetry [2, 3] in community-acquired pneumonia (CAP) severity scoring. For initial triage, the severity of CAP should be assessed by simple physiologic parameters, including oxygen saturation, blood pressure and respiratory rate. Biomarkers and lactate may help to refine prediction in specific subsets [4]. The majority of studies assessing severity in CAP patients are conducted in the emergency department (ED). Scores more frequently used in the ED, such as the Pulmonary Severity Index, usually underestimate severity, particularly in young patients, and perform poorly in predicting ICU admission. Patients who score above 90 points are classified as class V, and this is an heterogeneous group. Therefore, we believe there is a need for novel ways of stratifying CAP patients. New severity assessment tools should stratify different classes of severity of illness, because the degree of systemic response is not always predictive of outcome. An ideal severity score for CAP should be simple and easy to perform, reflect acute physiological alterations (injury-related) and consider factors such as age, co-morbidities, degree of injury and organ dysfunction. Along these lines, Rui Moreno et al. [5] recently reported a study with a new method for classifying sepsis, which includes criteria not only for infection, but also for predisposition of the patient and response of the organism to injury. We suggest that a score inspired by this concept [6] might improve our ability to assess severity and stratify risk of death in ICU patients admitted with CAP. Pulse oximetry should form part of the triage at the ED, being a simple, cheap and largely available method of identifying poor perfusion and early oxygenation assessment. References