2 studies question lung treatments


New study results call into question two common treatments for more than 190,000 Americans with life-threatening lung disease each year, researchers said.

Giving patients large doses of intravenous saline, done to support the heart and improve blood flow to other organs, adds to fluid buildup in the lungs and hampers recovery, one study showed. A second found that threading a sophisticated catheter through the heart to measure blood flow and pressure increases complications without improving care.

The results should permanently alter the way patients with acute lung injury and respiratory distress syndrome are treated, according to doctors who conducted the research. The two studies stem from a 1,000-patient trial funded by the National Heart, Lung, and Blood Institute, one of the largest ever done involving critically ill lung patients.

"There is mounting evidence that a catheter that was used very commonly, now that it's being rigorously studied, appears to have less and less application in routine use," said Arthur Wheeler, one of the lead researchers of the study and an associate professor of medicine at Vanderbilt University in Nashville, Tenn. In addition, "you want as little fluid accumulating as possible," he said in a phone interview.

As many as 60 percent of those who develop acute lung injury or the more serious respiratory distress syndrome each year die, studies show. The condition typically occurs in patients with other ailments, such as pneumonia. There is no specific treatment.

The studies were presented this week at a meeting of the American Thoracic Society in San Diego. The research on the pulmonary-artery catheter was scheduled to appear in yesterday's New England Journal of Medicine, and the findings on fluid management will appear in the June 15 edition.

In the first study, patients getting a pulmonary-artery catheter, or PAC, didn't have better survival or organ function than those who received a shorter catheter that provides doctors with less information on the heart and lungs. Patients with the PAC also were more likely to develop erratic heart rhythms known as arrhythmias.

The findings add to recent studies that show the devices aren't beneficial for critically ill surgery patients or those with heart failure or severe blood infections, Wheeler said.

The history of the catheters, introduced in 1970 before manufacturers had to prove devices benefited patients, "illustrates a great deal about physicians' often uncritical acceptance of technology," Deborah Shure, a Miami lung expert and former president of the American College of Chest Physicians, wrote in an editorial.

"The bottom line with respect to PAC use is that it should no longer be part of the routine management of a number of conditions for which it has been widely used," she said.

In the second study, researchers found patients given smaller amounts of extra fluids for seven days had better lung function, spent less time on a ventilator and were released sooner from intensive care than those given more liberal doses. There were no differences in death rates.

"Based on these results, we recommend that a conservative fluid management approach be used," said Herbert P. Wiedemann, chairman of pulmonary, allergy and critical care medicine at the Cleveland Clinic and lead author of the study. "Less time on the ventilator and fewer days in the ICU could translate into cost savings and lower risk for patients."

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