Six-month survival of patients with acute lung injury: Prospective cohort study* Murat Yilmaz, MD; Remzi Iscimen, MD; Mark T. Keegan, MD; Nicholas E. Vlahakis, MD; Bekele Afessa, MD; Rolf D. Hubmayr, MD; Ognjen Gajic, MD, MSC A cute lung injury (ALI) is a com- mon critical care syndrome that carries significant morbidity and mortality (1). Recent advances in invasive (2, 3) and noninvasive (4) me- chanical ventilation, sepsis resuscitation (5, 6), glucose control (7), preventive strate- gies (8), and intensive care unit (ICU) struc- ture (9) have had a profound impact on the management of patients with ALI. Both short- and long-term outcome studies con- ducted thus far were performed before the full implementation of these changes (10 – 13), most often within the context of clin- ical trials enrolling the minority of patients with ALI (10, 14, 15). To standardize care and facilitate the implementation of evi- dence-based therapies, we have introduced several hospital-based protocols, including low tidal volume ventilation protocol, stan- dardized weaning and sedation protocols, glucose control protocol, and restrictive transfusion protocol. In this prospective co- hort study, we aimed to determine the prognostic factors for hospital and 6-month survival of patients with ALI admitted to the ICU after the full implementation of recent evidence-based critical care inter- ventions. In addition to addressing the se- verity of pulmonary and nonpulmonary or- gan dysfunction, we specifically assessed the impact of the following potentially im- portant prognostic factors: a) underlying comorbidities; b) presence or absence of specific clinical trial (Acute Respiratory Distress Syndrome Network [ARDSNet]) exclusion criteria (2, 15); and c) admission source (transfer admissions from the an- other hospital or another ward in the same hospital and patients admitted from within of outside local community (Olmsted County)] (16). MATERIALS AND METHODS The institutional review board approved the study protocol. Daily screening identified consecutive patients with ALI who were ad- mitted to three ICUs (medical, surgical, and mixed medical-surgical) in the two Mayo Clinic Hospitals from October 2005 to May 2006. Patients who did not give research au- thorization and those with a do-not-resusci- tate order on admission were excluded. ALI was defined as acute onset of hypoxemia: PaO 2 / Objective: Both short- and long-term outcome studies in acute lung injury (ALI) performed thus far were conducted before the implementation of recent advances in mechanical ventilation and supportive care and/or in the context of clinical trials with re- stricted inclusion criteria. We sought to determine the outcome of consecutive acute lung injury patients after the implementation of these interventions. Design: Prospective cohort study. Setting: Three intensive care units of two tertiary care hospitals. Patients: Patients with acute lung injury treated from October 2005 to May 2006, excluding those with no research authorization or do-not-resuscitate order. Interventions: None. Measurements and Main Results: The investigators collected detailed information about comorbidities, severity of pulmonary and nonpulmonary organ failures, complications, respiratory support, and other interventions. The main outcome measure was mortality 6 months after the onset of acute lung injury. From 142 patients enrolled over a 6-month period, 24 (17%) died in the intensive care unit, 38 (27%) in the hospital, and 55 (39%) by the end of the 6-month follow-up. Median (interquartile range) intensive care unit length of stay, duration of mechanical ventilation, and number of day 28 ventilator-free days were 7.1 (3.6 –11.3), 5.7 (2.6 –10.3), and, 19.0 (0 –24.2) days. Multiple logistic regression analysis identified under- lying Charlson comorbidity score (odds ratio 3.11, 95% confidence interval 2.01–5.05) for each point increase, transfer admission from the floor or outside hospital (odds ratio 3.75, 95% confidence interval 1.41–10.99), day 3 cardiovascular failure (odds ratio 3.30, 95% con- fidence interval 1.19 –9.92), and day 3 PaO 2 /FIO 2 (odds ratio 0.94, 95% confidence interval 0.88 – 0.99) as significant predictors of 6-month mortality. Conclusions: With the implementation of recent advances in mechanical ventilation and supportive care, premorbid condition is the most important determinant of acute lung injury survival. (Crit Care Med 2007; 35:D1–D10) KEY WORDS: acute lung injury; intensive care units; risk factors prognosis; cohort; outcome assessment *See also p. 2441. From the Department of Internal Medicine, Division of Pulmonary and Critical Care Medicine (MY, RI, NEV, BA, RDH, OG), Department of Anesthesiology, Division of Critical Care Medicine (MTK), and Mayo Epidemiol- ogy and Translational Research in Intensive Care (M.E.T.R.I.C.) (MTK, NEV, BA, RDH, OG), Mayo Clinic, Rochester, MN; the Department of Anesthesiology and Intensive Care, Akdeniz University, Medical Faculty, Antalya, Turkey (MY); and Department of Anaesthesi- ology and Reanimation, Uludag University School of Medicine, Bursa, Turkey (RI). Supported, in part, by grant K23 HL087843-01A from the National Heart, Lung, and Blood Institute. The authors have not disclosed any potential con- flicts of interest. Address requests for reprints to: Ognjen Gajic, MD, Mayo Clinic, 200 First Street SW, Rochester, MN 55905; E-mail: gajjc.ognjen@mayo.edu Copyright © 2007 by the Society of Critical Care Medicine and Lippincott Williams & Wilkins DOI: 10.1097/01.CCM.0000284505.96481.24 D1 Crit Care Med 2007 Vol. 35, No. 10