Normal Active Hyperemia demonstrated: Figure 1:
In order to better appreciate this new clinical data, we ask to review some basics. Figure 1- This graph depicts a new technology that permits us to visualize real-time, simultaneous Patient / Mattress Interface Pressures and Deep Tissue Oxygen Tensions. This example displays only the Ischium pressure and tissue Oxygen values for purposes of clarity. Our standard studies include scapula, ischium, sacrum, trochanter, and heels. The subject changed position from a standing to a supine position, then elevated to a 70 degree recline and returned to a standing position in 20 minute intervals. In both standing and supine positions, ischium tissue oxygen averaged 55% while the ischium pressure averaged 26mmHg in the supine position.
In the 70 degree position, a majority of the subject’s weight transfers to the ischium. The average interface pressure rises to 99mmHg while the ischium oxygen tension only decreased to 51%. The net pressure from the supine to sitting position increased over 280%, but the oxygen only decreased by 6.5%.
This is an example of the normal human body’s ability to auto-regulate blood perfusion (normal active hyperemia) and demonstrates how pressure and blood perfusion are not inversely proportional in the majority (90%+) of patients that are able to perform clinically meaningful auto-regulation / active hyperemia.
Such patients represent a negligible pressure injury risk and should be clinically evaluated for non-powered mattress systems in order to improve patient satisfaction, true restorative sleep, leading to improved outcomes and reduced Length of Stay. Reference 4
In 2008, Medicare declined to reimburse for care costs related to hospital acquired pressure (HAPU) ulcers. As a result, a wide range of powered mattress systems were promoted and sold as the standard of care at that time for Pressure Ulcer prevention.
Our research and independent clinical trial experience demonstrates that the majority (90% +) of acute and sub-acute patients are sensate, semi-ambulatory and capable of functional normal active hyperemia and by definition, do not require, or benefit from powered mattress systems.
Independent clinical evaluations of mattress systems also confirm career nursing experience that the heat, noise and movement of powered mattress systems can promote insomnia and induce significant sleep deprivation that may require medication and can retard rehabilitation and increase Length of Stay.
Clearly, powered mattress systems are not clinically required for all patients. However, a meaningful, scientific method of determining relative pressure injury risk and objectively evaluating and designing clinical mattress systems is needed.
The authors developed a real-time, simultaneous patient / mattress pressure mapping / deep tissue blood perfusion – oxygen tension measurement system in order to actually quantitate patient adaption to interface pressures, mattress pressure induced ischemia and relative Injury / ulcer risk. This new technology is patent pending.
Using this new technology, Life Support Technologies group (LST) evaluated sixteen (16) commercially available alternating, low air loss and non-powered Mattress systems during 200+ manned tests from 2008-2015. These studies simultaneously compared total patient / mattress interfacial pressures and deep tissue oxygen tensions in up to 8 anatomical locations considered at greatest risk for pressure injury and ulcer development.
These locations included the occipital, scapula, elbows, trochanter, ischium, sacrum and heels. The scapula, ischium, sacrum and heel were eventually determined to be at greatest risk for pressure injury and became the standard test locations. Tests were conducted with subjects in supine, 30°, and 70°positions. Twenty (20) test subjects, 8 Females and 12 Males ranging from 18-65 years of age, including 2 paraplegic patients were studied.
Figure 2– Multiple averaged tests were conducted using non-invasive tissue oxygen measurements at four different anatomical locations with subjects resting on the non-powered OXY-MAT ™. Results for the powered mattress systems were taken with multiple subjects and were averaged on 5 different Alternating Mattresses and 6 different Low Air Mattress designs. [Reference 4, 5]
Independent Clinical Trials
In two independent clinical trials, a total of 103 in-patients were evaluated on powered mattress systems and then transferred to the newly developed non-powered mattress system. [Reference 5]
A 17 in-patient hospital trial published data demonstrated a $48,000 annual (2013) reduction in powered mattress rentals and without the need for heel boots. The same study also demonstrated a Hospital Acquired Pressure Ulcer (HAPU) incidence reduction from 5.5% at the start of 2013 trial and down to 1.24% by the third quarter. [Figure 3- Reference 6]
Figure 3: Reference 6
Another major (440 bed) Nursing and Rehabilitation Center trial of 83 in-patients [Reference 7] demonstrated the new non-powered mattress system [Figure 3. Reference 4,5] improved sleep, had no new skin breakdowns, existing Stage 3-4 ulcers were stable or improving and existing rash-dermatitis improved to clearing. Four patients had a reduction in pain medication. Two patients preferred to return back to powered beds. This institution has recommended the non-powered mattress system as the standard resident mattress and is converting. [Reference 5, 7]
As of November 2016, several other major (100+ bed) trials are in progress with similar preliminary outcomes resulting in a reduction in powered mattress utilization and rental costs with improved patient satisfaction and clinical outcomes according to independent medical staffs.
1. For over 60 years, healthcare mattress systems have been designed solely on patient/mattress interfacial pressure mapping and subjective comfort. Our research and clinical trials support the predominant literature that pressure mapping alone is not a reliable real-time indicator of mattress design superiority.
2. The 2008 assumption that placing all patients on elaborate powered mattress systems would mitigate pressure ulcers and reduce costs has demonstrated to be largely incorrect. The over-utilization of powered mattress systems has resulted in millions of dollars in unnecessary healthcare costs for powered mattress equipment.
3. It is estimated that 90%+ of all hospital and long-term care facility patients are capable of clinically functional normal active hyperemia and should only be placed on non-powered equalizing mattress systems to improve restorative sleep and lower cost of care. Only Patients incapable of semi-ambulatory movement and / or unable to induce normal active hyperemia should be placed in powered mattresses systems that can induce involuntary movement.
4. Tissue interface pressure and blood perfusion are not inversely proportional. Simultaneous pressure/oxygen saturation testing indicates that there is no positive correlation between increased patient/mattress interface pressures and decreased blood perfusion in tissue measured as Oxygen by NIR Spectroscopy.
5. The pathophysiology of pressure ulcer development is just beginning to be understood. The true dynamics of repetitive ischemia/reperfusion injury as they relate to deep-tissue oxygen/nutrient supply and cell metabolite management are critical to pressure injury prevention, ulcer development, and wound care. [Reference 3,4]
6. The time and tissue interface pressures required to induce an ischemic / reperfusion injury event vary significantly from patient to patient with age, co-morbidities, and functional circulatory auto-regulation as major factors. [Reference 3,4]
7. Flat architecture mattress systems tend to suspend the leg between the gluteal muscles / trochanter and the heel. This places focal pressure on the heels and can induce near immediate ischemia towards a pressure injury as demonstrated during actual pressure / oxygen testing. Also in this position, the knee joint is locked and induces a proprioceptive autonomic feedback that can inhibit deep restorative sleep. It is recommended that flat powered mattress systems not be used without elevating the heels or using protective boots. [Reference 4]
8. In extensive laboratory testing and clinical trials, the Oxy- Mat™ Mattress System was shown to be functionally superior to Group 2 powered mattresses by consistently lowering averaged interface pressures and permitting increased natural deep tissue oxygen values as compared to 16 commercially available powered and non-powered mattress systems.
1. Agency for Healthcare Research and Quality, Rockville, MD, January 2015 http://www.ahrq.gov/professionals/systems/long-term-care/resources/pressure-ulcers/index.html
2. McInnes E, Dumville JC, Jammali-Blasi A, Bell-Syer SEM. Support surfaces for treating pressure ulcers. Cochrane Database of Systematic Reviews 2011, Issue 12. Art. No.:CD009490. DOI: 10.1002/14651858.CD009490
3. Zamboni WA, Stephenson LL, Roth AC, et al. Ischemia-reperfusion injury in skeletal muscle: CD 18-dependant neutrophil-endothelial adhesion and arteriolar vasoconstriction. Plast Reconstr Surg 1997;99(7):2002–7.
4. Butler G, Kenyon D, Golembe E, et al. Oxy-Mat Mattress System Development Utilizing Simultaneous Measurement of Interface Pressure and Deep Tissue Oxygen Saturation. Surg Tech Int. 2015; XXVI:71-82 A PubMed Abstract is available: http://www.ncbi.nlm.nih.gov/m/pubmed/26054994/
5. OXY-MAT ™CMS / Medicare Homecare #EO373 Advance Pressure Reducing Mattress; USA & Foreign Patents Awarded 9,295,599 & 7,761,945 – Patent Pending US20130281804-A1, Meets Canadian Bed Entrapment Standards
6. Donatelli E, Rogers C, Adler, M. New York Presbyterian Hudson Valley Hospital – Cost Savings and Pressure Injury / Ulcer Reduction in a 7-week Clinical Trial of a Non-Powered Pressure Redistribution Mattress System Design. Magnet Hospital Innovation Report 2013, SAWC-Fall 2016 Poster Presentation.
7. Quality Assurance / Performance Improvement Report –Effectiveness of OXY-MAT Therapeutic Mattress February 2014, Gurwin Jewish Nursing and Rehabilitation Center.
Glenn J Butler , Scott Gorenstein , Edward Golembe , Bok Lee 
Life Support Technologies group , Winthrop University Hospital , Westchester Medical Center , New York Medical College 
Glenn Butler is a co-inventor of the pressure / oxygen mattress evaluation system and the OXY-MAT™ Optimized Perfusion Technology. Butler is founder / owner of LST and a partner in Off-Loading Technologies, Inc.
Life Support Technologies
580 White Plains Road, Suite 110, Tarrytown NY 10591 | www.LifeSupport-USA.com | 914-333-8412
Off-Loading Technologies, Inc
www.OffLoad-USA.com | 800-547-9899 | Info@Offload-USA.com