By Martina Tierney, OT
I’m often asked about pressure management in seating and specifically in relation to the cushions.
There is a lot of incorrect information out there in terms of pressure management and cushions, so I wanted to write an article to outline some of the challenges around this issue and provide some evidence-based solutions.
This information will be useful for enterostomal nurses, wound care nurses or tissue viability nurses who will all primarily be dealing with wound care but also occupational therapists, physiotherapists, care assistants and anyone dealing with seating to manage pressure risk in patients with low mobility.
When considering pressure management for a patient at risk of pressure injuries, pressure ulcers, wounds or skin redness (sometimes referred to as bed sores) traditionally two things have been utilised in response:
- A specialist mattress or therapeutic surface such as an air alternating or low air loss mattress.
- Pressure cushions e.g. air alternating, gel, foam-based cushions.
There are some good pressure cushions available which can contribute to protecting the integrity of the patient’s skin. These are long-standing products which are widely used and well marketed around the world.
However, when I teach therapists and clinicians, I explain how the cushion is only ¼ of the solution when it comes to pressure management in seating.
When clinicians are considering pressure management in seating, it is still common practice for many to think mainly about the cushion on the chair and not the other features of the chair itself. This can often lead to an over reliance on high cost pressure cushions to solve this clinical problem with mixed results.
The other chair components have a vital impact on pressure redistribution in seating and without considering these other features, the patient may still be at risk of pressure ulcer development, even with the specialist cushion in place.
Which Patients Are At Risk of Pressure Injuries?
- Patients with low or no mobility due to their age, an accident or illness, who sit for long periods of the day.
- Patients who cannot reposition themselves independently when they get uncomfortable. These patients might slump to one side, forward or slide down the chair, needing help from carers or family members to regain a mid-line posture.
- Patients who have thin or fragile skin and who are a high pressure injury risk.
- Patients who are hoisted for all transfers.
Where Problems Arise with Pressure Cushions
Often key things are missed in terms of reducing pressure injuries in seating by adding just a pressure cushion to a patient’s chair to redistribute or ‘relieve’ pressure, without considering the other aspects of the patient’s seat.
By focusing on the cushion alone, key opportunities for combating pressure injuries are being missed and we can sometimes increase the risk to the patient.
The Body Is Not Loaded Properly
Pressure is reduced by increasing the surface area contact of the person’s body with the chair.
When the body is loaded properly, the feet, legs, back, arms and head are all in contact with the seat.
However, often a specialist pressure cushion is placed on top of a standard armchair, sofa, wheelchair or existing specialist chair. When this happens, we could be adding pressure to their seated area.
How? The addition of the cushion alters the fixed dimensions of the chair, often lifting the person’s feet off the ground or off their footplate meaning they are dangling or bearing less weight. Up to 19% of the person’s body weight can be taken through the feet when loaded properly in seating and so without a footplate, this weight from their feet is now going through their seat, increasing the pressure.
Therefore, even though they might have a good cushion, the weight and pressure in their seated area is increasing.
No Postural Support
If a pressure cushion has been stacked on top of an existing standard cushion, or placed on a chair which is too wide, it can reduce the effectiveness of the arms, lateral supports and head rests in holding the person in a good posture.
In many cases, you can tell just by looking at the patient that they probably do not feel stable nor supported by the chair. They may not be able to reach the armrests. Their feet may be dangling and not reaching the floor. They might have their arms crossed to stabilise themselves in the seat. They might also be leaning to the side, leaning forward or sliding from the chair. Each of these factors can create friction and shearing forces and can also increase the weight going through one side of the body compared to the other and therefore lead to the development of pressure injuries. Adding a cushion and not considering how this affects postural support can therefore detrimentally affect pressure.
No Ability for Repositioning
A chair which does not have tilt in space, such as an armchair, a riser recliner or a sofa, does not allow the patient to independently shift their weight when they become uncomfortable.
Shifting weight or repositioning, can lead to increased blood oxygenation and therefore reduce the risk of pressure injuries.
This repositioning should happen a minimum of once every 2 hours and is often required by international healthcare guidelines.
The chair needs to allow this effective weight shift to happen by use of functions such as tilt in space, to correctly and effectively redistribute pressure off bony parts of the body. Simply adding a cushion does not achieve this.
The Chair is Already Unsuitable
Adding a pressure cushion to a chair which is maybe already unsuitable for the patient will not solve the problem fully. If the dimensions of the chair are too big and it does not provide postural support or effective repositioning, simply adding a pressure cushion will not be an effective solution for the patient.
The Four Principles of Clinical. Therapeutic Seating
To prevent pressure injuries in seating we should look at the whole chair, not just the cushion.
- Load the Body.
- Provide Postural Support.
- Allow Effective Repositioning.
- Use an Appropriate Surface.
The cushion will not likely be most effective unless the first three principles have been implemented.
Seating Matters Pressure Cushions
The Seating Matters standard cushion is made up of two distinct layers:
- First Layer: Two inches of memory foam to allow immersion and envelopment of the Ischial Tuberosities (ITs) into the cushion, this immersion gives stability and reduces shear and friction. It’s widely accepted that the ITs need to immerse two inches into their surface for maximum support.
- Second Layer: A dense layer of foam which provides stability to the pelvis and to the top layer of memory foam.
TIP: Test the effectiveness of your cushion with the ‘bounce back’ test. Press the palm of your hand firmly into the cushion, the contours of your hand should be enveloped by the foam, then remove your hand. The foam should bounce right back.
We would recommend for new chair users that you should assess the user and if appropriate, use the Seating Matters cushion in conjunction with the Four Principles of Pressure Management. This is likely to provide medium to high pressure management.
For those at risk of pressure injuries or those who may already have a Grade 3 or 4 pressure injury or open wound, we would recommend that you consult with a Tissue Viability Nurse for their input and refer to your own facility guidelines.
Our clinically tested cushion is provided on all Seating Matters chairs as standard and is removable. If you are having success with using another cushion we suggest that you can continue to use it on the Seating Matters chair, adapting the dimensions of the chair to enable the full loading of the body.
*Note: The purpose of this blog is to give an overview of the product with some tips to consider on its use. This is not intended to be a substitute for professional or medical advice, diagnosis, prescription or treatment and does not constitute medical or other professional advice. For advice with your personal health or that of someone in your care, consult your doctor or appropriate medical professional.
*Note: The resulting report from this randomized control trial shows that the study consisted of 38 participants from 3 nursing home settings, who were randomly assigned to control and intervention groups using computer-generated numbers. The study’s results in regard to pressure ulcers has been calculated from the change in pressure ulcers/pressure injuries/skin redness in both the intervention and control group. As a pilot study of a specific nature, it was not blinded. The measurement of pressure ulcers was observational and the analysis of the results included various forms, not including statistical analysis. The study has been reviewed and presented at over 30 academic conferences in 3 continents and is pending publication in a respected peer-reviewed journal.
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