SUNDAY, May 21, 2006 (HealthDay News) -- A major study has answered two knotty questions for doctors treating patients with the severe lung injury called acute respiratory distress syndrome (ARDS).
The issues may seem esoteric, but they can be literally of life-and-death importance to the estimated 190,000 Americans who suffer from the syndrome each year because of complications from conditions such as a major infection or severe injuries.
Those conditions can cause a buildup of fluid in the lungs that cuts oxygen flow to the blood. The effect on the heart, liver, kidney and other organs is severe enough to kill 30 percent to 60 percent of ARDS patients.
The U.S. government-sponsored study sought to answer two questions: When monitoring a patient's condition, is it better to use a long catheter, which is a tube threaded into the heart, or a shorter catheter? And should intravenous fluids be provided in abundance or sparingly?
The answers, based on a study of 1,000 patients in 20 medical centers across the country, favor use of the shorter catheter and less fluid.
The findings were expected to be presented Sunday at the International Conference of the American Thoracic Society, in San Diego, and will also be published in two pieces in the May 25 and June 15 issues of the New England Journal of Medicine.
The longer catheter provides more information about the patient's condition but increases the risk of damage as it is threaded through blood vessels, said Dr. Herbert P. Wiedemann, chairman of the department of pulmonary, allergy and critical care medicine at the Cleveland Clinic, who presented the report on that aspect of the study.
"The question was whether the information from the longer catheter would offset the risk of damage," Wiedemann said. "In this patient population, it did not."
The longer catheter might be advisable in patients with significant heart problems, he added, but the study results point against its general use.
As for the second finding, researcher Dr. Arthur P. Wheeler, an associate professor of medicine at Vanderbilt University, said, "Patients who get more conservative fluid treatment come off the ventilator faster and leave the intensive care unit faster. And that translates to better outcomes for the patients, but also is of economic importance."
Patients getting less fluid left the ICU two and a half days earlier than those getting more, Wheeler said. "In patients who have lung injury, when you administer fluid into the air spaces of the lung, that impairs the ability to get oxygen into the blood. The basic idea is that you get water out of the lung, allowing it to function better," Wheeler said.
The study also showed a slight improvement in survival, 3 percent, in patients getting less fluid, but not enough to reach statistical significance, Wheeler said. "But from the patient and family standpoint, being able to breathe on your own several days sooner and leave the ICU sooner, that is important," he said.
The study results will be of note to all physicians treating patients with ARDS, Wheeler said. "All medical studies take time to be adopted," he said. "This will influence practice in terms not only of the catheter that is used but also in terms of a more conservative fluid strategy in patients who are not in shock."
For more on ARDS, visit the National Library of Medicine.