June 16, 2006

Fewer fluids for ARDS patients: study

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Art Wheeler, M.D.

Fewer fluids for ARDS patients: study

Vanderbilt University Medical Center has long been recognized as a leader in acute lung injury research.

In the past month, Art Wheeler, M.D., and his team published three separate studies in the New England Journal of Medicine highlighting the need to rethink three of the standard treatment modalities used in Acute Respiratory Distress Syndrome (ARDS) patients.

The most recent study compared two fluid management strategies commonly used in the treatment of ARDS patients — a conservative and liberal approach. While there has been no standard treatment in regards to fluid management, the study findings point to the use of a conservative strategy for overall improvement in the conditions of lung injury patients.

“What we found was that the mortality rate using the conservative fluid strategy was about 3 percent lower than the liberal strategy,” said Wheeler. “Although that is a relatively small survival difference, what we also found was that the conservative strategy produced significant improvement in lung function, the patients were removed from the ventilators 2.5 days faster, and there was no increased risk of damage to any other organs.

“The liberal fluid management is what most doctors were doing in practice. What we have shown is that by giving less fluid and using diuretics to get the fluid out of the patients, it helps get them off the vents faster, out of the ICU faster and, if anything, it is associated with a lower death rate.”

Wheeler explained that the treatment philosophy of caring for this population of patients has been to give lots of fluid so that the heart puts out a high flow and helps prevent the organ failure. But there is a hefty price to pay for administering large amounts of fluid — often the fluid leaks into the lungs and it is much more difficult to get oxygen into the blood stream. The conservative strategy reversed these outcomes and provided a healthier environment for the lungs.

Not only were patient outcomes improved, but the financial savings were also substantial.

“The big development here is that we have been able to show you can improve clinical outcomes by not giving the fluid and taking it off as soon as it is safe by using diuretics,” said Wheeler.

“For those practitioners who are used to giving lots of fluids, this is likely to change practice. When you get patients off vents 2-3 days sooner, it's not only a big deal to the patient and family, it's a big deal monetarily. You are cutting the hospital bill down considerably for survivors.”

This approach to treatment has been proven to be safe and effective, according to study results.

The five-year study looked at 1,000 ARDS patients at participating centers of the ARDS Clinical Research Network of the National Heart, Lung and Blood Institute (NHLBI), part of the National Institutes of Health. VUMN, under the direction of Gordon Bernard, M.D., who leads the steering committee of the NIH/NHLBI ARDS Network, has conducted a myriad of studies aimed at improving the treatments for ARDS.

The disease affects nearly 150,000 in the United States annually, with a mortality rate ranging between 35 percent and 70 percent. The most common causes are pneumonia, sepsis and trauma.

“From a layman's point of view, if you put gallons of fluid into a patient, eventually you have to figure out how to get it out,” said Wheeler. “Using the liberal strategy, the average patient gained about a liter of fluid every day. At the end of the week, a patient would weigh roughly 15 pounds more.

“One of the most distressing things to a patient family is for them to see their loved one grossly swollen with fluid. It's a cosmetic issue, but I wouldn't be surprised to find that some patient families will feel more at ease with the appearance that more closely resembles normal than one dramatically swollen.”