NATO Litter: Fluid Immersion System (FIS) Versus Traditional Mattress for Pressure Dispersion

The purpose of this study is to measure peak skin interface pressures and the total area of the body exposed to skin interface pressure above 30 mm Hg at different areas of the body in the supine position on two different support surfaces applied to a standard North Atlantic Treaty Organization (NATO) litter (NSN: 6530-01-380-7309) and a Raven 90C Litter (NSN6530-01-432-5114). The support surfaces are the Warrior Evacuation Litter Pad (WELP) and the Dolphin Fluid Immersion Simulation Stretcher System (FIS). These pressure measurements and transcutaneous oxygenation readings will allow us to determine differences between support surfaces.

The purpose of this study is to measure peak skin interface pressures and the total area of the body exposed to skin interface pressure above 30 mm Hg at different areas of the body in the supine position on two different support surfaces applied to a standard North Atlantic Treaty Organization (NATO) litter (NSN: 6530-01-380-7309) and a Raven 90C Litter (NSN6530-01-432-5114). The Raven 90C is the official litter for the U.S. Navy. It is approved for flight on United States Air Force (USAF) aircraft. It can be easily folded for storage and transport to remote settings. The support surfaces are the Warrior Evacuation Litter Pad (WELP) and the Dolphin Fluid Immersion Simulation Stretcher System (FIS). In theory, mattresses that reduce and/or minimize pressure on the capillary bed's perfusion can help reduce pressure related injury such as pressure or decubitus ulcer development. Skin interface pressure measurements using a pressure mapping system and transcutaneous oxygenation readings will allow us to determine these differences between support surfaces. A better understanding of skin interface pressure associated with the litter support surfaces is vital for military nurses to develop and implement preventative interventions to reduce pressure ulcer development in our patients. In addition, this study will provide information to help determine the usefulness and feasibility of incorporating the fluid immersion system (FIS) as a litter support surface.

This research protocol has one major aim:

To determine the difference in the pressure redistribution qualities between the WELP and the Dolphin FIS

There are also two secondary aims:

1. To determine the difference in the pressure redistribution qualities of the WELP when used as the mattress on the NATO litter and Raven litter.
2. To determine the difference in the pressure redistribution qualities of the Dolphin FIS when used as the mattress on the NATO litter and Raven litter.

Eligibility Criteria:
Inclusion Criteria:

* Adults over the age of 18 years with lawful access to Travis Air Force Base (AFB)

Exclusion Criteria:

* Orthopedic or neurological conditions that prevent a subject from lying flat (supine) without any pillows for head, neck, or lumbar support
* Medical conditions (such as an uncontrollable tremor or twitch) that prevent a subject from staying still for the required periods of time (20 minute increments).
* Pregnancy
* Inability to ambulate unassisted, unstable gate (presenting increased fall risk)
* Extremity prosthetics (hand/arm or foot/leg)
* Height greater than 72 inches (6 feet) - exceeds length of the litter \& mattress surfaces
* Body weight greater than 300 lbs
* Subjects who find it difficult, uncomfortable or impossible to remain still for the necessary study time durations (20 minute increments) on the relatively narrow litter surfaces will be removed from the study.
* Subject does not speak or understand the English language