First, in collaboration with Dr. Keith Lurie who developed a device that creates resistance during inspiration, we were able to find a simple operationally feasible way of counteracting syncope and hemorrhagic shock when one deals with returning astronauts or casualties on the battlefield. We demonstrated that reducing intrathoracic pressure can be an effective noninvasive resuscitation tool for restoring central blood volume as a ‘bridge’ to more definitive care where fluids may not be readily available. This therapy can be applied by having spontaneously breathing patients inspire through resistance which results in a greater vacuum within the thorax, and subsequently enhances venous return and preload to the heart in conditions of central hypovolemia (e.g., hemorrhage). In this sense, a resuscitation effect can be provided without the challenges created by carrying and infusing fluids that can dilute clotting factors or dislodge clots with elevated blood pressure. Using LBNP as our simulated progressive hemorrhage model in humans, my post-doctoral fellow Caroline Rickards demonstrated that this intrathoracic pressure regulation (IPR) therapy is capable of delaying symptoms as well as hemodynamic decompensation by protecting cerebral blood flow in addition to maintaining cardiac output [18]. Our work has led to a documented case where use of IPR therapy proved its value as a lifesaving intervention in a combat casualty. In addition to its usefulness in treating casualties with hemorrhage, the discovery that IPR therapy reduces intracranial pressure [17] speaks to its potential value as an early noninvasive intervention in the pre-hospital setting for treatment of cerebral hypoperfusion associated with traumatic brain injury. Most significantly, this technology has been placed by the US Army Tactical Combat Medical Care for use in the treatment of hypovolemic hypotension in Battalion Aid Stations and all air and land ambulances in theater, and recognized for its value to returning astronauts by its placement in the medical kit on board the Space Shuttle and International Space Station. As one of the most gratifying experiences in my career, the impedance threshold device technology used to apply IPR therapy was inducted into the Space Foundation Hall of Fame in 2008 (Fig. 6).
Fig. 6 Vic Convertino, Keith Lurie, Don Doerr, and Ahamed Idris receiving their medals while attending the Space Technology Hall of Fame Induction ceremony at Colorado Springs, Colorado on April 10, 2008