Abstract
OBJECTIVE: To survey the incidence and outcome of acute lung injury (ALI)/acute respiratory distress syndrome (ARDS) in critical care units and to estimate the population-based incidence of ALI/ARDS in Chiba prefecture
DESIGN: Prospective multicenter cohort study
SETTINGS: Twelve intensive care units (ICUs) including 7 of 8 tertiary critical care centers and 4 of 6 university hospitals in Chiba prefecture
METHODS: All patients admitted to ICUs in 12 hospitals from October 1-December 31, 2004 were prospectively screened for SIRS (systemic inflammatory response syndrome) and ALI/ARDS based on the definitions of the 1992 ACCP/SCCM Consensus Conference and 1994 American-European Consensus Conference, respectively. For the ALI/ARDS patients, the following data were collected; patient background, causes of ALI/ARDS, severity of illness (APACHE II), organ dysfunction (SOFA), PaO2/FIO2 (P/F ratio), mechanical ventilation, therapeutic intervention other than mechanical ventilation, ICU stay, and 28-day mortality.
RESULTS: During the study period, 1632 patients were admitted to the participating units, and 770 (47.2%) met the criteria for SIRS. Seventy-nine patients were diagnosed with ALI/ARDS, which comprised 4.8% of all ICU patients, and 10.3% of patients with SIRS. In ALI/ARDS patients the mean age was 64.0 ± 17.1, P/F ratio was 150.7 ± 70.6; with 19 and 60 patients exhibiting P/F ratios 300-201 and ≤ 200, respectively. The mean APACHE II score, SOFA score, and organ dysfunction other than lung were 24.7 ± 8.9, 8.8 ± 4.3, and 2.2 ± 1.4, respectively. Seventy-one out of 79 patients with ALI/ARDS received mechanical ventilation, and the average number of ventilator free days (VFD) was 12.1 ± 10.6. The average ICU stay was 18.8 ± 9.6 days and 28-day survival in ALI/ARDS patients was 68.4%.
CONCLUSIONS: Based on the population, we estimated the incidence of ALI/ARDS as 6.1 per 100,000 persons per year in Chiba prefecture.
