Recovery Rate and Prognosis in Older Persons Who Develop Acute Lung Injury and the Acute Respiratory Distress Syndrome

Recovery Rate and Prognosis in Older Persons Who Develop Acute Lung Injury and the Acute Respiratory Distress Syndrome

E. Wesley Ely, MD, MPH;
Arthur P. Wheeler, MD;
B. Taylor Thompson, MD;
Marek Ancukiewicz, PhD;
Kenneth P. Steinberg, MD;
Gordon R. Bernard, MD; and
for the Acute Respiratory Distress Syndrome Network

From Vanderbilt University School of Medicine and the Veterans Affairs Tennessee Valley Healthcare Research and Clinical Education Center, Nashville, Tennessee; Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts; and Harborview Medical Center, University of Washington School of Medicine, Seattle, Washington.

Abstract

Background: The incidence of acute respiratory failure requiring mechanical ventilation increases 10-fold from the ages of 55 to 85 years, yet the rate of recovery and outcomes in older persons who develop acute lung injury are poorly defined.

Objective: To examine age as an independent risk factor in recovery and intensive care unit discharge after acute lung injury.

Design: Prospective cohort study.

Setting: 10 U.S. university-based medical centers.

Patients: 902 mechanically ventilated patients enrolled in randomized, controlled trials for the treatment of acute lung injury. All patients were managed according to a standardized protocol for ventilator management and weaning.

Measurements: Frequency and time to achieve well-defined recovery landmarks, duration of ventilation and intensive care unit stay, and survival.

Results: Median duration of mechanical ventilation was 19 days (interquartile range, 7 to >28 days) for patients 70 years of age or older (n = 173) compared with 10 days (interquartile range, 5 to 26 days) for patients younger than 70 years of age (n = 729) (P < 0.001). The duration of intensive care unit stay was 21 days for the older group (interquartile range, 11 to >28 days) and 16 days for the younger group (8 to >28 days) (P = 0.004). Survival rates decreased across increasing decades of age (P < 0.001): Patients younger than 70 years of age had a greater 28-day survival rate than patients 70 years of age or older (74.6% vs. 50.3%; P < 0.001). The proportion of survivors achieving physiologic recovery landmarks did not differ between the older and younger age groups, and the median time to pass a 2-hour spontaneous breathing trial was similar between both the older and younger patients (4 days vs. 5 days; P > 0.2). After passing a spontaneous breathing trial, however, older patients required 1 more day than younger patients to achieve unassisted breathing (P = 0.002) and 3 more days to leave the intensive care unit (P = 0.005). In a multivariable Cox proportional-hazards analysis, age of 70 years or older was a strong predictor of in-hospital death (hazard ratio, 2.5 [95% CI, 2.0 to 3.2]; P < 0.001).

Conclusions: Although the survival rate among patients 70 years of age or older was high, these patients were twice as likely to die of acute lung injury compared with their younger counterparts, even after adjustment for covariates. Older survivors recovered from respiratory failure and achieved spontaneous breathing at the same rate as younger patients but had greater difficulty achieving liberation from the ventilator and being discharged from the intensive care unit.

Article and Author Information

Presented in part at the International Conference of the American Lung Association and the American Thoracic Society on 8 May 2000 in Toronto, Ontario, Canada.
Acknowledgment: The authors thank Dr. William Hazzard, one of the nation's premier leaders in geriatric medicine, for raising our awareness of the importance of age-related issues in the decision making and care of critically ill older persons.
Grant Support: By contracts (NO1-HR 46054-46064) with the U.S. National Heart, Lung, and Blood Institute. Dr. Ely is a recipient of an American Federation for Aging Research Pharmacology in Aging Grant and the Paul Beeson Faculty Scholar Award from the Alliance for Aging Research. He is a recipient of a K23 from the National Institutes of Health (#AG01023-01A1) and is a Geriatric Research and Education Clinical Center investigator.
Requests for Single Reprints: E. Wesley Ely, MD, MPH, Division of Allergy, Pulmonary, and Critical Care Medicine, Center for Health Services Research, 6th Floor, #6109 Medical Center East, Vanderbilt University Medical Center, Nashville, TN 37232-8300; e-mail, wes.ely{at}mcmail.vanderbilt.edu.
Current Author Addresses: Dr. Ely: Division of Allergy, Pulmonary, and Critical Care Medicine, Center for Health Services Research, 6th Floor, #6109 Medical Center East, Vanderbilt University Medical Center, Nashville, TN 37232-8300.
Dr. Wheeler: Vanderbilt Medical Center, T-1217 Medical Center North, Nashville, TN 37232-2650.
Dr. Thompson: Massachusetts General Hospital, Bulfinch 148, 55 Fruit Street, Boston MA 02114.
Dr. Ancukiewicz: Radiation-Oncology Department, Harvard University, 55 Fruit Street, Boston, MA 02114.
Dr. Steinberg: Harborview Medical Center, 325 9th Avenue, Seattle, WA 98104.
Dr. Bernard: Vanderbilt Medical Center, T-1208 Medical Center North, Nashville, TN 37232-2650.
Author Contributions: Conception and design: E.W. Ely, A.P. Wheeler, B.T. Thompson, M. Ancukiewicz, K.P. Steinberg, and G.R. Bernard.
Analysis and interpretation of the data: E.W. Ely, A.P. Wheeler, B.T. Thompson, M. Ancukiewicz, K.P. Steinberg, and G.R. Bernard.
Drafting of the article: E.W. Ely, A.P. Wheeler, M. Ancukiewicz.
Critical revision of the article for important intellectual content: E.W. Ely, A.P. Wheeler, B.T. Thompson, M. Ancukiewicz, K.P. Steinberg, and G.R. Bernard.
Final approval of the article: E.W. Ely, A.P. Wheeler, B.T. Thompson, M. Ancukiewicz, K.P. Steinberg, and G.R. Bernard.
Provision of study materials or patients: E.W. Ely, A.P. Wheeler, B.T. Thompson, M. Ancukiewicz, K.P. Steinberg, and G.R. Bernard.
Statistical expertise: E.W. Ely.
Obtaining of funding: E.W. Ely, A.P. Wheeler, B.T. Thompson, M. Ancukiewicz, and G.R. Bernard.
Administrative, technical, or logistic support: E.W. Ely, A.P. Wheeler, B.T. Thompson, M. Ancukiewicz, and G.R. Bernard.
Collection and assembly of data: E.W. Ely, A.P. Wheeler, B.T. Thompson, M. Ancukiewicz, and G.R. Bernard.