Noninvasive Treatment of Hemorrhagic Shock

Hemorrhagic shock is the leading cause of death in combat injuries. This application focuses on a novel way to treat hemorrhagic shock using a new device called the inspiratory impedance threshold device (ITD). The ITD increases blood pressure and survival rates in animals in hemorrhagic shock. Phase I studies in human volunteers are intended to demonstrate proof of concept that use of the ITD is a) feasible, b) tolerable, and c) will increase cardiac stroke volume and stabilize blood pressure in normotensive and hypotensive subjects. In spontaneously breathing subjects the ITD creates a small vacuum within the chest, forcing more blood from the extra-thoracic veins into the heart with each inspiration. This results in an increase in blood pressure, without an immediate need for intravenous fluids or surgical intervention. Phase II studies will focus on use of the ITD in volunteers subjected to hypotension simulating battlefield shock in a lower body negative pressure chamber and in hypotensive patients in the emergency room. The studies are designed to demonstrate that the ITD can "buy time", until more definitive care is available. The studies will shed new light on the mechanisms and treatment of hemorrhagic shock, with important military and civilian applications.