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who can get on and off with greater
ease and can stabilise the mattress
surface before returning to bed with
minimal or no assistance from others.
The mattress also incorporates
audible and visual alarms, including
power failure and high or low
pressure indicators.
Pressure mapping
The aim of this study was to investigate
the performance of the Carital Optima
mattress using dynamic interface
pressure measurements. This work
was performed under laboratory
conditions with healthy volunteers. The bed and mattress were set
up and calibrated according to the
manufacturer’s instructions. Each subject
rested upon the mattress in a supine
and lateral position for one full cycle of
the mattress pressure adjustment (the
equilibration cycle). Data acquisition was
performed using a Tekscan Dual Mat
system at 8Hz via a USB port (Figure
3) which measures interface pressures
between the patient and the mattress. Data was captured for the duration
of the 15-minute equilibration cycle
and the two mats were positioned to
provide continuous coverage. The cycle |
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allows the cells of the mattress in head, thorax, and leg segments to adjust their
pressures to give the maximum support
for the subject. In effect, the contact
area between mattress and subject is
increased, thus reducing local pressure. The cycle is activated by the movement
of the subject.
Care was taken to ensure that the mats were positioned consistently in relation to the underlying structure of the Optima mattress and that the measurement surface was not folded or creased during loading. The maximum interface pressure and mean contact area were then measured.
The results illustrated that, over time, the mattress adjusts to increase the contact area between the body and mattress – thus reducing pressure. Typically, area increases of 25% have been obtained (Figures 4 and 5)
among all subjects evaluated in the study to date. This information is more informative than the single-point pressure values obtained on small areas with static measurements as it shows how the mattress’s cellular structure adjusts to the contours of the human body by reducing the air pressure in |
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heavily loaded areas and increasing pressure in the lightly loaded areas — thus redistributing the total pressure. This technology permits pressure mapping once the subject has changed position and triggered the mattress’ equilibration cycle.
According to separate studies conducted by Soppi and Takala (2005) and White et al (2007), the Carital Carital Optima mattress effectively reduces the pressure between the patient and the support surface. This translates clinically into prevention of ulceration in acute respiratory failure (Takala et al, 1996), and, in the authors’ ongoing formal evaluations, pain relief and improved sleep in a variety of chronic disorders.
Case report one
The patient, aged 81 years, had Alzheimer’s disease for several years. She had severe contractures to all four limbs, was underweight and unable to verbally communicate, although she could produce facial expressions signifying pain, comfort and approval/
disapproval of nursing interventions.
She had been resident in a nursing home since 2003 and required permanent urinary catheterisation and frequent attention for faecal incontinence. She also needed repositioning every two hours, a time frame established by the care team as most comfortable for her. The patient was totally dependent on nursing staff for all of her care and was restless at night with a poor quality of sleep.
During the summer of 2007, she became unwell with pyrexia that required antibiotics. She also developed a grade 4 sacral ulcer (EPUAP, 1998) that measured 5.5cm long X 5.2cm wide and was 3cm deep with 80% slough over the wound bed and 20% non-granulating tissue. Dressing changes using Aquacel Ag (ConvaTec, Ickenham), as prescribed by the primary care trust’s tissue viability nurse were required frequently due to faecal incontinence. Morphine was also required for pain caused by the dressing changes.
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