PRE-ILLNESS PULMONARY FUNCTION TESTING DOES NOT PREDICT CLINICAL OUTCOMES FROM THE ACUTE RESPIRATORY DISTRESS SYNDROME
Brianna Triplett1, Rebecca Baron2, Diana Barragan Bradford2.
1University of Alaska, Anchorage, Anchorage, AK, 2Harvard Medical School, Boston, MA.
Acute respiratory distress syndrome (ARDS) results in respiratory failure characterized by bilateral lung infiltrates that cause hypoxemia. We looked at whether underlying lung dysfunction predicts clinical outcomes from ARDS. Patients were selected from the Brigham and Women’s Registry of Critical Illness (ROCI). All ARDS subjects were screened (as well as matched controls) for pre-existing pulmonary function tests (PFTs) obtained prior to medical intensive care unit (MICU) admission and for clinical information. This information was used to determine correlations between pre-existing pulmonary comorbidities with the success of extubation and rates of re-intubation. Of the 560 patients in the ROCI, 102 were designated as ARDS and of those, 21 subjects had pre-existing PFTs. The ARDS subjects had a forced expiratory volume in 1-second (FEV1) range of 0.68 to 3.85 L (33 to 85% of predicted), a total lung capacity (TLC) range of 1.36 to 7.13 L (27 to 135% of predicted), and a diffusing capacity (DLCO) of 0.94 to 21.76 L (4 to 68% of predicted). We similarly examined subjects without ARDS who required mechanical ventilation and identified 18 subjects who had pre-existing PFTs performed. The non-ARDS subjects had a FEV1 range of 0.48 and 3.07 L (17 to 80% of predicted), TLC range of 2.77 to 4.96 L (50 to 82% of predicted) and DLCO range of 5.19 to 15.48 (19 to 65% of predicted). There was no correlation between PFT results and mortality in both the ARDS and non-ARDS cohorts. While underlying lung disease leads one to worry about ARDS prognosis, our data does not support using pre-existing pulmonary function data to predict clinical outcomes.