Retrospective analysis on acute respiratory distress syndrome in ICU.

OBJECTIVE: To assess the incidence, etiology, physiological and clinical features, mortality, and predictors of acute respiratory distress syndrome (ARDS) in intensive care unit (ICU).

METHODS: A retrospective analysis of 5 314 patients admitted to the ICU of our hospital from April 1994 to December 2003 was performed in this study. The ARDS patients were identified with the criteria of the American-European Consensus Conference (AECC). Acute physiology and chronic health evaluation III (APACHE III), multiple organ dysfunction syndrome score (MODS score), and lung injury score (LIS) were determined on the onset day of ARDS for all the patients. Other recorded variables included age, sex, biochemical indicators, blood gas analysis, length of stay in ICU, length of ventilation, presence or absence of tracheostomy, ventilation variables, elective operation or emergency operation.

RESULTS: Totally, 131 patients (2.5%) developed ARDS, among whom, 12 patients were excluded from this study because they died within 24 hours and other 4 patients were also excluded for their incomplete information. Therefore, there were only 115 cases (62 males and 53 females, aged 22-75 years, 58 years on average) left, accounting for 2.2% of the total admitted patients. Their average ICU stay was (11.27+/-7.24) days and APACHE III score was 17.23+/-7.21. Pneumonia and sepsis were the main cause of ARDS. The non-survivors were obviously older and showed significant difference in the ICU length of stay and length of ventilation as compared with the survivors. On admission, the non-survivors had significantly higher MODS and lower BE (base excess). The hospital mortality was 55.7%. The main cause of death was multiple organ failure. Predictors of death at the onset of ARDS were advanced age, MODS > or = to 8, and LIS > or = 2.76.

CONCLUSIONS: ARDS is a frequent syndrome in this cohort. Sepsis and pneumonia are the most common risk factors. The main cause of death is multiple organ failure. The mortality is high but similar to most recent series including severe comorbidities. Based on this patient population, advanced age, MODS score, and LIS may be the important prognostic indicators for ARDS.