RT Book, Section A1 Pickens, Chiagozie I. A1 Wunderink, Richard G. A1 Waterer, Grant W. A2 Schmidt, Gregory A. A2 Kress, John P. A2 Douglas, Ivor S. SR Print(0) ID 1201805137 T1 Severe Community-Acquired Pneumonia T2 Hall, Schmidt and Wood’s Principles of Critical Care, 5th Edition YR 2023 FD 2023 PB McGraw Hill PP New York, NY SN 9781264264353 LK accessmedicine.mhmedical.com/content.aspx?aid=1201805137 RD 2024/10/15 AB KEY POINTSPneumonia is one of the most common causes of ICU admission, usually because of impending respiratory failure or hemodynamic compromise.Community-acquired pneumonia (CAP) is the leading cause of infectious death around the world and a frequent cause of ICU admission.HCAP (Healthcare-associated pneumonia) is no longer an entity. Use of the HCAP designation resulted in excessive use of broad spectrum antibiotics.Severe CAP (SCAP) is defined as CAP associated with mechanical ventilation and/or shock requiring vasopressors, or having three or more minor American Thoracic Society criteria.Patients initially admitted to a non-ICU setting but subsequently requiring ICU transfer have high mortality that exceeds that of patients with equivalent illness at presentation who are admitted directly to the ICU. Presence of at least three of a set of minor criteria for severity identifies patients likely needing ICU care and the probability increases with an increasing number of these minor criteria.The diagnostic evaluation for the etiology of pneumonia in hospitalized patients with SCAP is most commonly negative. When a pathogen is identified, it is most commonly a virus. The most common bacterial etiologies of SCAP are Streptococcus pneumoniae and Staphylococcus aureus.The etiologies of SCAP are rarely multidrug resistance and in the absence of risk factors, empirical antibiotics for SCAP should be a combination of a beta-lactam plus a macrolide.