Incidence and risk factors for mortality in acute respiratory distress syndrome. Do we have the same predictors?

Objectives

To know the density of incidence and annual punctual prevalence, mortality and main factors for death in acute respiratory distress syndrome (ARDS) in our patients.

Materials and methods

Cohort study, retrolective and prolective. Secular period: All the admissions of the intensive care unit (ICU) in 1 year (March-1-99 to Feb-29-00). Zero point was considered the admission of the ICU continuing follow up until the outcome: discharge from the ICU or death. We included all those patients that completed criteria of ARDS according to the American-European consensus (1994). The risk factors were defined to all factors associated with ARDS during the first 24 hours and were classified as direct or indirect. The following variables were defined: age, gender, number of days in ICU and hospital, comorbility, APACHE II (admission), factors associated to the development of ARDS, time between risk factors and start of mechanical ventilation and duration of the same with complications, less PaO₂/FiO₂, maximum PEEP, use of Swan–Ganz catheter and amines (dopamine >5 μg/kg/min, norepinephryne and epinephryne), type of nutrition and causes of death.

Statistical analysis

Program SPSS 9.0 was used, unvaried analysis with χ² and exact Fisher tests. P was considered significant < 0.05.

Results

550 cases were reviewed. Forty fullfilled criteria of ARDS (18 men and 22 woman). The punctual prevalent was 8.8% and the incidence was 19 per 100 anual. The mortality was 55%. Of the evaluated variables P < 0.05 was found between living and death: the number of days in ICU and hospital stay, APACHE II (admission) and less PaO₂/FiO₂. The risk factors found asociated were direct (30%), indirect (45%) and both (25%).

Conclusions

The punctual prevalence was 8.8%. The Incidence was 19 per 100 anual. ARDS is an important cause of death (55%) and the independent variables for mortality found were: APACHE II > 18 and less PaO₂/FiO₂ < 100 with OR 50.66 and CI 95% (7.51–341).