A new study funded by the U.S. Food and Drug Administration is underway by Emory physicians at Grady Memorial Hospital to find an effective treatment for patients with acute lung injury.
Lead study investigator Greg S. Martin, MD, says despite less than 200,000 reported cases each year, "acute lung injury is not an uncommon disease for critically ill patients. Every published study notes that between 10 and 25 percent of critically ill patients have this disease, and it's something we see frequently in the ICU." Martin is assistant professor of medicine (pulmonary, allergy and critical care medicine) in Emory University School of Medicine.
Acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) are inflammatory disorders of the lung most commonly caused by sepsis, pneumonia, trauma and/or aspiration.
"These disorders can elicit an immune response that creates such an exaggerated amount of inflammation that the lung becomes injured," says Martin. "When the lung becomes injured it doesn't work properly and gas exchange doesn't occur normally. People with this severe form of lung injury end up on a respirator and there is no real treatment."
Previous clinical trials have shown that combination colloid and diuretic therapy greatly improves oxygenation and fluid balance in ALI/ARDS patients without compromising their cardiovascular stability.
In this study, Martin and his team will follow 60 patients, comparing two drug combinations that have not previously been assessed. In a randomized, double-blind, controlled design, 30 patients will receive continuous infusion furosemide with 5 percent albumin and 30 patients will receive 6 percent hetastarch. The treatment will last for five days and patients will be assessed during and afterwards for improvements in lung function and dependence on the mechanical respirator.
Martin says these specific drug combinations were chosen because they are very complementary. Studying their interactions will give researchers a better understanding of the biochemistry and physiology of the disease.
"These drugs should help to resorb some of the excess fluid in the lung from ALI/ARDS as well as improve some of the inflammation and other stress that the body withstands, and thus improve gas exchange from the lung," he says. "If we're right about some of the preliminary data, this treatment could reduce the length of time on the ventilator."
In ALI the lung is injured and develops a thick fluid that accumulates in the lungs and causes swelling or edema. Current strategies attempt to remove that edema or block the inflammation that causes the edema.
Treatment includes mechanical ventilation, supportive care and treatment of underlying causes, but Martin notes, "Studies of ALI or ARDS over the past 30 years have all failed to find anything that is directly effective. At Emory we've been working for a number of years on strategies that help prevent the accumulation of edema to start with and affect the way fluid might be removed more quickly."
According to Martin, the mortality rate for patients with ALI and ARDS is approximately 40 percent. Those who survive usually are on a ventilator for several weeks, often resulting in severe consequences, including weakness, brain impairment and reduced quality of life.
"ALI is a relatively common condition in the ICU for which there is no treatment," says Martin. "We're hoping to find something that will get people off the ventilator sooner and perhaps improve their outcome. Unfortunately, individuals must be critically ill to be eligible for this study -- they cannot volunteer on their own. However, it is important for people to know that Emory University and Grady Memorial Hospital are working hard on something that really can make a difference for these patients."
Martin treats patients in both pulmonary and critical care medicine at Grady Memorial Hospital, Emory Crawford Long Hospital and Emory University Hospital. He also trains fellows in pulmonary and critical care medicine and directs the Medical and Coronary Intensive Care Units at Grady Memorial Hospital.