Simple Change in Ventilator Reduces Deaths

March 10, 2000
News Office: Wallace Ravven (415) 502-6397

A nationwide study, including patients at UCSF Medical Center, has found that a simple adjustment in the way patients receive breathing assistance can cut mortality by 22 percent among victims of acute respiratory distress syndrome (ARDS), an often fatal lung condition that affects between 100,000 and 150,000 people annually in the United States.

Results of the 861-patient study will be published in May in the new England Journal of Medicine, but strong interest in the findings have prompted the journal to release the findings on their web site www.nejm.org. The article is titled, "A Comparison of Ventilation with Traditional Tidal Volumes and Lower Tidal Volumes for Acute Lung Injury and the Acute Respiratory Distress Syndrome."

"This is a real breakthrough in treatment of a devastating condition," said Dr. Michael Matthay, who practices critical care medicine at UCSF Medical Center. Matthay is principal investigator in the 10-city study and a professor of medicine and anesthesia at UCSF. "More patients die each year from ARDS than from breast cancer, and to be able to save some 20,000 lives with this change in the ventilators is very gratifying."

Last year, the study, funded by the National Institutes of Health, was stopped ahead of schedule to alert critical care specialists of the life-saving results, and news of preliminary findings circulated at that time. The news released on the NEJM web site reports the study's final results, which also will appear later in the journal.

ARDS patients, usually already hospitalized for other conditions, become severely short of breath, needing intensive care, usually with a mechanical ventilator. Excess fluid in the lungs displaces oxygen and leads to respiratory failure, Matthay said.

The oxygen-rich puffs of air provided to patients in the new technique are only about half the volume of those used in conventional ventilation therapy for ARDS. It had been thought that larger volumes would improve transfer of oxygen from the lungs to the blood. However, the results of this study indicate that the larger volumes worsen the degree of lung injury.

In addition to the UCSF Medical Center, the hospitals involved in the three-year study are affiliated with the Cleveland Clinic, Duke University, Johns Hopkins University, University of Colorado, University of Michigan, University of Pennsylvania, University of Utah, University of Washington and Vanderbilt University. The study was coordinated at Massachusetts General Hospital in Boston.