Help available for recovering lungs

A University of Pittsburgh researcher has developed a device that functions like a temporary set of lungs.

Brack Hattler, a professor of surgery at the University of Pittsburgh School of Medicine, said laboratory and animal studies suggest the device could do an adequate job of exchanging carbon dioxide and oxygen in patients with damaged lungs, allowing the lungs to rest and heal.

Clinical trials of the device, dubbed the Hattler Respiratory Catheter, are expected to begin in Europe in about a year. About 10 years ago, clinical testing of another device was halted because the device’s design did not allow for sufficient gas exchange.

Together with bioengineer William J. Federspiel, Ph.D., Dr Hattler has created an intravenous respiratory device that is inserted through a vein in the leg and positioned into the vena cava, the major vein returning blood to the heart.

It consists of hollow fibre membranes that introduce oxygen into and remove carbon dioxide from the body. Key to its design, and a distinction from the device that failed, is a central balloon within the fibres that can inflate and deflate at a rate of 300 beats per minute to move the fibres and mix the blood.

This is said to allow for more efficient oxygenation of blood and removal of carbon dioxide. In essence, respiration takes place even though the lungs are severely injured and functioning poorly.

The surface area of two human lungs is about the size of a tennis court. The Hattler Catheter has a surface area equivalent to a sheet of paper and can perform about 50 percent of the gas exchange requirements of an adult.

The device is not envisioned for prolonged support or as a total replacement of the lungs. However, findings from the clinical trial could lead to a greater understanding of what is required for the development of more long-term devices, Dr Hattler said.