Organ dysfunction and failure in severe community-acquired pneumonia

Severe community-acquired pneumonia (SCAP) patients admitted to the ICU were prospectively followed for development of MODS, multiple organ failure (MOF), etiologic diagnosis (ED) and clinical outcome. Methods: Definitions and discrimination between OD and OF were based on APACHE (AP) III data. MODS and MOF were defined as mild (1 organ), moderate (2-3), and severe (≥4). Analysis was performed on OD and OF present on the day of admission (DOA) to the ICU. From 1/1/93 through 12/31/95, 181 patients with SCAP were prospectively followed. APII and APIII scores were calculated, as well as actual (AM), APII predicted mortality (PM), & length of ICU stay (LOS). Results: OD was present in 177 patients (98%) on DOA: mild OD 27.1%, mod OD 49.2%, and severe OD 23.7%. Average APII/APIII scores were: mild OD 17.0/60.1, mod OD 22.8/79.7, severe OD 28.3/107.8. LOS: mild OD 10.5 days, mod OD 12.2 days, and severe OD15 days. AM and PM for mild OD was 15.4%/29.0%, mod OD 27.6%/45.8%, and severe OD 52.4%/63.2%. The most frequent single OD was renal (79.2%) while neuro/renal was the most common combination (65.9% of all MODS patients). OF was present in 84 (46.4%) patients on DOA: mild-59.5%, mod-38.1%, and severe-2.4% (2 patients). Average APII/APIII scores were mild-22.8/82.6, mod-30.1/ 117.3 compared with 19.0/64.6 for patients without OF. LOS was 12.3 days for no OF, 11.4 days for mild, and 13.9 for mod. AM and PM were mild-30.0%/46.3%, mod-65.6%/69.8% compared with 16.5%/34.7% for patients without OF. The most frequent single OF was cardiovascular [CV] (44%). The most common combinations were CV/ renal (10.7% of all OF, 50% of MOF) and CV/heme (8.3%, 35.3%) ED was determined in 53.6% with no OF, 42.3%/56.8% with mild OD/OF, mod OD/OF 64.4%/78.1% and 71.4%/100% with severe. Patients with mod/severe OF were significantly (p<0.02) more likely to have nonfermenters or S. pneumoniae cultured. Conclusions: Organ dysfunction, particularly renal, is common on admission in SCAP. Organ failure was more commonly cardiovascular, mainly shock. Moderate or severe MOFS is more commonly associated with infection with nonfermenters and S. pneumoniae. Clinical Implications: This study further defines OD/OF and the etiology of SCAP.