FIRST CLINICAL DATA WITH A HIGH TECH LOW AIR LOSS MATTRESS

Dr Maarten J. Lubbers

Pressure Ulcers (bedsores, decubitus) are a common, but in most cases preventable, problem among hospitalised patients. An extensive prevalence survey conducted in 43 Dutch acute-care hospitals revealed a mean prevalence of 21.6%.1 Patients admitted to intensive care units (ICU’s) are at particularly high risk of developing pressure ulcers. These patients are generally not able to signal increased tissue pressure and react accordingly, because they have received analgesics, sedation or muscle relaxants.2,3 The surgery itself, anaesthesia, inotropics and positive pressure ventilation may adversely affect the pump action of the heart, leading to reduced blood circulation in the skin and underlying tissues.1 Incidence and prevalence studies involving ICU’s are scarce and they report rates ranging from 1% to 66%.1,2,4,5 The prevalence of pressure ulcers in Dutch ICU’s is high: in the national prevalence survey it was 28.7%. Patients who had undergone surgery showed significantly higher prevalence of pressure ulcers than patients who had not (34.8% ÷ 25.1%). However, this study was a prevalence survey and cannot conclude from the data whether the ulcers occurred before or after surgery. Tutuarima et al showed in their study on pressure ulcers in three ICU’s that 31% suffered from hospital acquired P.U. Sacrum, ears and heels were most involved: 15%, 12% and 12%, respectively. Buttocks, mouth and back were affected in 5%, 4% and 4%. Cross tabulation on PU showed no association with gender, age, post surgery and Apache II. All patients were positioned on active pressure relief mattresses.

Noise level. Decreasing the noise at 10db, the noise level will be reduced to 50%.

Extra protection measures were practised for 80% of the patients. Protection of the heels and ears were each supplied to 60%, multiple positional turning and protection of the skin to 43%, and 38%.6 The EPUAP summary report on the prevalence of pressure ulcers stated that decubitus ulcers afflict one in five hospital patients. Surprisingly few patients apparently received fully appropriate interventions. The highest percentage allocated appropriate preventive care was found in the U.K. However, even in the U.K. fewer than 10% received fully appropriate preventive care. There is much scope for the improvement of pressure ulcer care.7

A variety of support surfaces are available for prevention and treatment of patients with or without pressure ulcers. The supports range from a plain slab of foam to complex beds. The challenge to the clinician is to choose the one that best meets the patient’s needs. Support surfaces are classified according to the Cullum systematic review (Table 1).8,9
Reger reviewed the physiology of soft tissue, shear and pressure-related injuries and the biomechanical principles of support surface function to aid the clinician in choosing the most appropriate support. In pressure ulcers the primary factors are pressure and shear. The secondary factors include temperature, moisture, applied load duration atrophy and posture. The quality of any support surface is a function of interface stresses and the microclimate at the patient-support contact. The clinician has two excellent technologies for controlling the skin-support surface interface: Air-Loss and Air-Fluidised.10 The critically ill ICU patient who is at risk for pressure ulcer development and does not tolerate turning because of haemodynamic instability or poor oxygenation may benefit from an oscillating low air loss therapy bed.4 There is enough evidence to advise that patients who do not get enough turning, lifting and mobilisation must be placed on pressure redistribution (= reducing/relieving) equipment.11 In these groups of high-risk patients, high tech devices (e.g., LAL and AF) are high priorities of research.4,7,8,9 There is very little published evidence available.9 Disadvantages of these high tech (LAL/AF) devices are the size, weight, noise and basic user interface.

We report the first clinical data with an improved LAL mattress, which is lighter, smaller, more user-friendly, and has reduced noise level (Table 2). Two SICU patients were treated (Table 3). Our conclusions (Table 4) were very positive: this new mattress seems a real improvement, especially the touch screen and the reduced noise level. We recommend a proper clinical RCT.

References
1. Bours GJJW, De Laat E, Halfens RJG, Lubbers MJ, Prevalence, risk factors and prevention of pressure ulcers in Dutch intensive care units. Intensive Care Med 2001, 27: 1599–1605.
2. Herman LE, Rothman KF, Prevention, care and treatment of pressure (decubitus) ulcer in intensive care unit patients. J Intensive Care Med 1989, 4: 117–123.
3. Goodrich C, March K, Form ED to ICU: a focus on prevention of skin breakdown. Crit Care Nurs 1992, Q15:1–13.
4. Peerless JR, Davies A, Klein D, Yu D, Skin complications in the ICU. Clinics in Chest Med 1999, 20: 453–467.
5. Weststrate JTM, Hop WCJ, Aalberts AGJ, Vreeding AWJ, Bruining HA, The clinical relevance of the Waterlow pressure sore risk scale in the ICU. Intensive Care Med 1998, 24: 815–20.
6. Tutuarima JA, Lubbers MJ, Vostermans J, Pressure ulcers: location and protection measures on three ICU’s of the AMC-Amsterdam, 7th EPUAP Congress 2003.
7. Clark M, Bours G De Floor T, Summary report on the prevalence of pressure ulcers, EPUAP Review 2002, 4: 49–57.
8. Cullum N, Nelson EA, Shellon T, Systematic reviews of wound care management. Health Technology Assessment 2001; 5(9).
9. McInnes E, The use of pressure-relieving devices for the prevention of pressure ulcers in primary and secondary care. A clinical practise guideline. J Tissue Viab 2004, 14: 4–23.
10. Reger SI, Validation test for climate control on air-loss support. Arch Phys Med Rehabil. 2001, 82: 597–603.
11. CBO report, Richtlijn decubitus, 2002, www.cbo.nl

Low-tech devices
• Standard foam mattress.
• Alternative foam mattresses or overlays (for example, high-specification foam, convoluted foam, viscoelastic, cubed foam). These are comfortable and aim to redistribute pressure over a larger contact area.
• Gel-fitted mattresses or overlays.
• Fibre-fitted mattresses or overlays.
• Fluid-filled mattresses or overlays.
• Air-filled mattresses or overlays.

High-tech devices
• Alternating-pressure devices: the patient lies on air-filled sacs, which sequentially inflate and deflate and relieve pressure at different anatomical sites for short periods. These devices may incorporate a pressure sensor.
• Air-fluidised devices: warmed air is circulated through fine ceramic beads covered by a permeable sheet. These allow support over a larger contact area.
• Low-air-loss devices: patients are supported on air-filled sacs inflated at a constant pressure, through which air is able to pass.
• Turning beds or frames (kinetic of profiling beds): beds that either aid manual repositioning of the patient or reposition the patient by motor-driven turning and tilting.

2 SICU patients:
• Female, 68 year, 70 kg, 1.65 m
4 x A, Apache II 29,3 days, dead
decubitus grade IV heel
• Female, 41 year, 72 kg, 1.70 m
Guillain-Barré, lung embolus, heparin, G-I bleeding
Apache II 18, 14 days, survived
decubitus grade III, sacrum

Conclusions:
better same worse
Touch screen : 88% 12% 0
Blower unit : 34% 66% 0
Noise : 66% 34% 0
Overall user friendly: 56% 44% 0