ARDS is severe form of respiratory failure with significant impact on the morbidity and mortality of critical care patients. Epidemiological data are crucial for evaluating the efficacy of therapeutic interventions, designing studies, and optimizing resource distribution. The goal of this review is to present general aspects of mortality data published over the past decades. A systematic search of the MEDLINE/PubMed was performed. The articles were divided according to their methodology, type of reported mortality, and time. The main outcome was mortality. Extracted data included study duration, number of patients, and number of centers. The mortality trends and current mortality were calculated for subgroups consisting of in-hospital, ICU, 28/30-d, and 60-d mortality over 3 time periods (A, before 1995; B, 1995–2000; C, after 2000). The retrospectivity and prospectivity were also taken into account. Moreover, we present the most recent mortality rates since 2010. One hundred seventy-seven articles were included in the final analysis. General mortality rates ranged from 11 to 87% in studies including subjects with ARDS of all etiologies (mixed group). Linear regression revealed that the study design (28/30-d or 60-d) significantly influenced the mortality rate. Reported mortality rates were higher in prospective studies, such as randomized controlled trials and prospective observational studies compared with retrospective observational studies. Mortality rates exhibited a linear decrease in relation to time period ( P < .001). The number of centers showed a significant negative correlation with mortality rates. The prospective observational studies did not have consistently higher mortality rates compared with randomized controlled trials. The mortality trends over 3 time periods (before 1995, 1995–2000, and after 2000) yielded variable results in general ARDS populations. However, a mortality decrease was present mostly in prospective studies. Since 2010, the overall rates of in-hospital, ICU, and 28/30-d and 60-d mortality were 45, 38, 30, and 32%, respectively.

The microbial etiology and source of sepsis influence the inflammatory response. Therefore, the plasma levels of cytokines (IL-6, IL-8, and IL-10), chemokines (CCL2/MCP-1, MIP-1β), heparin-binding protein (HBP), soluble CD14 (sCD14), and cortisol were analyzed in blood from septic patients obtained during the first 96 hours of intensive care unit hospitalization. The etiology was established in 56 out of a total of 62 patients enrolled in the study. Plasma concentrations of MCP-1, sCD14, IL-6, and IL-10 were significantly higher in patients with community-acquired pneumonia (CAP;n=10) and infective endocarditis (IE;n=11) compared to those with bacterial meningitis (BM;n=18). Next, cortisol levels were higher in IE patients than in those with BM and CAP, and at one time point, cortisol was also higher in patients with gram-negative sepsis when compared to those with gram-positive infections. Furthermore, cortisol and MCP-1 levels correlated positively with the daily measured SOFA score. In addition, HBP levels were significantly higher in patients with IE than in those with BM. Our findings suggest that MCP-1, sCD14, IL-6, IL-10, cortisol, and HBP are modulated by the source of sepsis and that elevated MCP-1 and cortisol plasma levels are associated with sepsis-induced organ dysfunction.