Severe Community-Acquired Pneumonia

Severe community-acquired pneumonia (SCAP) is the most lethal form of community-acquired pneumonia (CAP), with mortality rates exceeding 30% in cases involving shock or mechanical ventilation. Usually, SCAP represents 5 to 10% of all hospitalized patients with CAP. A pragmatic definition of SCAP is to refer to those patients with CAP who are admitted to the intensive care unit (ICU). This definition is likely biased due to the significant variability of ICU resources in different countries. Another way to define SCAP is by using the 2007 minor Infectious Diseases Society of America (IDSA)/American Thoracic Society (ATS) criteria (3 out of 9 criteria) or major criteria (shock or need for mechanical ventilation). These criteria have been in use since 2007 in clinical practice and for research purposes.