The National Pressure Ulcer Advisory Panel's (NPUAP) Support Surface Standards Initiative (S3I) has released the first version of its Terms and Definitions Document. This set of definitions is provided in an attempt to redefine commonly used and confused terms. The terms describe support surface features, components, categories, and performance characteristics.
The Terms and Definitions Document and an evaluation form can be found at NPUAP`s site
Critically ill patients, unable to move spontaneously, are nursed in the supine position for extended periods of time. This is in striking contrast to normal human beings who, even during sleep, change their position approximately every 11.6 min–a phenomenon described by Keane as "minimum physiological mobility requirement." The deleterious effects of prolonged immobilization affect the heart, vascular system, musculoskeletal system, skin, and kidneys, despite the usual nursing practice of repositioning every two hours.