University of Michigan and Arts et Métiers ParisTech solve a medical mystery: 'We started with fundamental flow physics and physiology'

Researchers at the University of Michigan and Arts et Métiers ParisTech have been able to figure out a 125-year-old medical mystery that could help treat patients with fluid buildup in their lungs.

Dr. James Grotberg, a professor of biomedical engineering at the University of Michigan, and Francesco Romano, an associate professor of fluid mechanics at Arts et Métiers ParisTech who once served as a postdoctoral researcher in Grotberg's lab, believe they've determined how fluid leaves the lungs of patients who have recovered from pulmonary edema. 

"Since no one had done this before, we started with fundamental flow physics and physiology. The fluid is serum leaking from the blood vessels into the air sacs—that’s pulmonary edema," Grotberg said in a press release from the University of Michigan. "Meanwhile, the lymphatic system acts like a vacuum, drawing excess fluid out of the tissues. But the lymphatics were far away, too far for their suction to be effective. Given that problem set-up, we used mathematical modeling to simulate both how pulmonary edema builds up and how the body clears it.

Pulmonary edema, or the buildup of fluid in the lungs, can be Fata. The release pointed out that the fluid can accumulate in air sacs which makes it harder for the lungs to function. In addition, the fluid can bring oxygen levels low enough to kill someone. The researchers used math to recreate how lungs retain fluid and how the body gets rid of it. It was paid for by the National Institutes of Health. 

During the study, researchers found a mechanism that forces extra fluid from the air sacs to the distant lymphatics. Groberg explained that their model could provide insight into how to treat fluid buildup. The model takes into account "anatomical and physiological parameter values of the lung, as well as clinical interventions, and then simulates how the entire system works," he said in the release. It can predict how fluid levels in the lungs will respond to changing conditions.

This new physiological flow that they have discovered is a "key ingredient" to diagnosing and treating fluid bbuildup Grotberg believes that it is relevant to "both major causes of pulmonary edema: elevated lung blood pressure, a symptom of congestive heart failure, and the breakdown of the air-blood barrier that can occur with infections like COVID-19 and RSV."  Their research could shed more light on how lungs function. Their study report presented several situations where the new model may be applied, opening doors for discoveries.