Gerald Supinski, MD, professor and vice chair of research for the department of internal medicine at the university, is investigating respiratory weakness as a factor in the morbidity of intensive-care patients, and will soon be testing new treatments to improve long-term patient outcomes while reducing costs of care.

Supinski suggests that patients who are exposed to prolonged mechanical ventilation in the intensive care unit (ICU) develop weakness in the skeletal muscles. As a result, he believes that muscle wasting is a significant factor in both extended ICU stays and the lengthy recovery times required after a patient has been removed from the ventilator.

"Only about 50% will return to their previous level of functioning within 9-12 months, and many will have damage lasting 5-years or longer," said Supinski.

Additionally, Supinski hypothesizes that physicians tend to significantly underestimate both the degree of patient weakness and the length of time that the patients will require mechanical ventilation. If effective treatments can be developed to slow down the wasting process reliance on mechanical ventilation can be reduced and recovery times will improve, according to Supinski.

The first phase of Supinski’s research involves assessing the respiratory strength of patients in the ICU using a measurement known as "Pdi twitch," which gauges pressures across the diaphragm. Supinski believes this provides a more objective measurement than other pulmonary function tests such as spirometry.

"Sometimes you can't be sure whether a patient is truly giving you full effort, especially when the patient is already weak" Supinski said. "This takes effort out of the equation."

For Pdi twitch measurement, a painless electrical stimulus is given to patients on either side of the neck, triggering nerves that cause the diaphragm to twitch. The twitch results in a change in pressure in the esophagus, which can be measured. The lower the pressure change, the greater the degree of weakness.

The second phase of the study will involve testing new treatments to slow down muscle wasting in ICU patients. Two drugs that show promise are eicosapentaenoic acid (EPA) and N-acetylcysteine (NAC), according to Supinski.

For the project, Supinski was awarded a 2-year, $480,000 per year NIH Challenge Grant.