Epidemiology of ARDS in a Brazilian ICU
© Biomed central limited 2001
Published: 1 March 2002
To describe the epidemiology of the acute respiratory distress syndrome (ARDS) in a Brazilian ICU.
This prospective observational, non-interventional study, included all consecutive patients with ARDS criteria  admitted in the ICU of a Brazilian tertiary hospital, between January 1997 and September 2001. Were collected in a prospective fashion the following variables: age, gender, APACHE II score at ICU admission and at ARDS diagnosis, cause of ARDS, presence of AIDS, cancer and immunosuppression, occurrence of barotrauma, performance of traqueostomy, mortality, duration of mechanical ventilation (MV), length of stay (LOS) in ICU and in hospital. The lung injury score (LIS)  was used to quantify the degree of pulmonary injury in the first week of ARDS.
There was 2182 patients (P) admitted in ICU during the study period, of whom 141(6.46%) had ARDS criteria. Seventy-six (54%) were men, the mean age was 46 ±18 years, APACHE II 18 ± 7 and 19 ± 7 at admission and at ARDS diagnosis, respectively. Septic shock accounted for 42%(60 P) of the ARDS causes, sepsis 22%(31 P), diffuse pulmonary infection 16%(23 P), aspiration pneumonia 11%(15 P), non-septic shock 5%(7 P) and others 4%(5 P). Ten percent (14 P) had AIDS, 30%(43 P) cancer and 25%(36 P) immunosuppression. All patients were mechanically ventilated with Tidal Volume between 4 and 8 ml/kg. Only 3.5%(5 P) had barotrauma and 10%(14 P) performed traqueostomy. Mortality rate was 79% in the ICU. The patients required 12 ± 10 days on MV, ranging from 1 to 55 days. The LOS in ICU and hospital was 14 ± 13 (1-69) days and 28 ± 32 (1-325) days, respectively. There was a time delay of 3.7 ± 4.5 days between admission in ICU and the onset of ARDS. The Murray score (mean ± SD) was 3.2 ± 0.4, 3 ± 0.5, 3 ± 0.5, 2.9 ± 0.6, 2.8 ± 0.7, 2.7 ± 0.7 and 2.6 ± 0.8 in the first 7 days, respectively.
ARDS in our hospital has a similar incidence of reports in the USA and Europe. There was a higher mortality, which could be explained by a high incidence of infection causes of ARDS, mainly septic shock, and elevated combined occurrence of AIDS, cancer and immunosuppression, along the degree of LIS. The incidence of barotrauma was low, as a consequence of the current mechanical ventilation strategies.