INCREASED MORTALITY OF OLDER PATIENTS WITH ACUTE RESPIRATORY-DISTRESSSYNDROME

Objective: To examine the relationship between age and mortality in AR DS patients and evaluate the importance of factors that increase the m ortality of older ARDS patients. Design: Prospective inception cohort study. Setting: Community-based referral hospital. Patients: Two hundr ed fifty-six ARDS patients identified from May 1987 to December 1990. ARDS was defined by the following: (1) PaO2/PAO(2) less than or equal to 0.2; (2) pulmonary capillary wedge pressure less than or equal to 1 5 mm Hg; (3) total static thoracic compliance less than or equal to 50 mL/cm H2O; (4) bilateral infiltrates on chest radiograph; and (5) an appropriate clinical setting for ARDS. Main outcome measures: Comparis on of organ failure, incidence of sepsis patient demographics, arteria l oxygenation, and level of support in those 55 years and younger and those older than 55 rears of age. Withdrawal of support in patients wh o died. Results: Seventy-two of 112 patients older than 55 years (64%) died us 65 of 144 patients 55 years and younger (45%) (p=0.002). Exam ination of patient groups using age identified older than 55 years as a ''cutpoint'' above which mortality was greater (p=0.002). Older nons urvivors did not differ from nonsurvivors 55 years or younger with res pect to gender, smoking history, ARDS risk factors, ARDS identifying c haracteristics, APACHE II (acute physiology and chronic health evaluat ion), number of organ failures, or the incidence of sepsis, In the 48 h prior to death, nonsurvivors 55 years and younger had more organ fai lure (3.4+/-0.2 vs 2.8+/-0.2; p=0.03), higher fraction of inspired oxy gen (0.82+/-0.03 vs 0.68+/-0.03; p=0.008), and higher positive end-exp iratory pressure levels (13+/-1 vs 8+/-1; p=0.001) than older nonsurvi vors. Despite more severe expression of disease, only 32 (50%) nonsurv ivors 55 years and younger had support withdrawn (p=0.009). Significan tly more nonsurvivors older than 55 years (73%) had support withdrawn (p=0.009). Even in the absence of chronic disease states, withdrawal w as more likely for patients older than 55 years (21/51) than in those 55 years and younger (3/32; p<0.001). Conclusion: Mortality is signifi cantly higher for patients with ARDS older than 55 years. Decisions to withdraw support are made more often in ARDS patients older than 55 y ears. These data suggest that age bias may influence decisions to with draw support.