Risk factors for outcomes of acute respiratory distress syndrome patients: a retrospective study

Background: The determination of risk factors for acute respiratory distress syndrome (ARDS) patients remains a challenge. Our study aims to explore the epidemiology and risk factors affecting outcomes of ARDS patients and provide a theoretical basis for patients' prognosis.

Methods: This retrospective study included 207 ARDS patients admitted to the general intensive care unit (ICU) in the Second Affiliated Hospital of Harbin Medical University from Jan 1st, 2016 to Jan 1st, 2017. The criteria were defined according to the Berlin Definition, and clinical data were collected from the medical record system. The mortality rate and duration of mechanical ventilation were compared in ARDS patients. Furthermore, logistic regression analysis was applied to screen clinically accessible risk factors for survival and duration of mechanical ventilation.

Results: The total mortality in ARDS patients was 39.13% (81/207) compared to 13.57% (151/1,113) in the whole ICU population. The period prevalence of mild, moderate and severe ARDS was 39.61% (82/207), 37.20% (77/207) and 23.19% (48/207), respectively. Logistic regression analysis showed that acute physiology and chronic health evaluation II (APACHE II) score (OR 3.4316; 95% CI: 1.3130-8.9686; P=0.0119), number of organ failure (OR 3.4928; 95% CI: 1.9775-6.1693; P<0.0001), mean arterial pressure (MAP) (OR 5.1049; 95% CI: 1.8317-14.2274; P=0.0018), driving pressure (OR 6.0017; 95% CI: 2.1746-16.5641; P=0.0005) and lactate level (OR 4.0754; 95% CI: 1.6114-10.3068; P=0.0030) were influence factors for survival; severity of ARDS (OR 1.6715; 95% CI: 1.0307-2.7108; P=0.0373), ventilator-associated pneumonia (VAP) (OR 7.3746; 95% CI: 2.9799-18.2505; P<0.0001) and transfusion history (OR 2.2822; 95% CI: 1.0462-4.9783; P=0.0381) were influence factors for duration of mechanical ventilation.

Conclusions: Higher APACHE II score, more organ failures, lower MAP, higher driving pressure and higher lactate level are risk factors for survival. Higher severity of ARDS, VAP and transfusion history are risk factors for prolonged duration of mechanical ventilation. Application of these parameters would enable intensivists to treat their patients more precisely and comprehensively.