Articles Clinical Blog

You ask, we answer.

How do I select the best mattress for my patient?   

This will depend on the patient’s condition, risk score, comfort and clinical judgement, as well as manufacturer guidance too.  For example, OSKA mattresses are colour coded to enable the appropriate mattress to be selected based on clinical risk & category of PU.  Think holistically but key things to look out for when selecting a mattress would be:

  • Will the surface meet the clinical, psychological and psychosocial needs of the patient?
  • Does it offer excellent immersion, envelopment and optimum skin microclimate?
  • Easy to reposition/ mobilise?



What is immersion and envelopment?  

Immersion and envelopment relate to how much a patient sinks into a support surface (immersion) and how much the support surface comes up around the body (envelopment).  The idea is to try to maximise the potential body contact with the support surface so that the total surface area is increased to reduce the interface pressure. The larger the surface area, the more pressure can be redistributed to lower the interface pressure. 



What causes pressure ulcers?  

Pressure ulcers are caused by many factors, but these factors can be placed into two categories –Extrinsic and Intrinsic factors.  Extrinsic pertaining to the environment (external to the patient) and intrinsic relating to the patient (internal). 

Extrinsic factors are pressure and shear – pressure and shear are forces which will always be present but we can reduce their effect on the patient for example by the use of support surfaces and other equipment such as the bed or correct chair height etc. 

Pressure pushes up and down and compresses the tissues between the bony prominence and the surface the patient is lying/ sitting/ even leaning on.  Blood vessels can also become compressed and if the pressure is applied for long enough, and is high enough to occlude the blood vessels, this can lead to tissue ischemia.  

Shear – shear is a gravity force pushing down on the patient’s body with resistance between the patient and the chair or bed.  Results in the bone sliding down but the skin and soft tissue ‘dragging’ against the bed or chair. 

Intrinsic factors such as patient medical condition can also play a part in PU development.

Other factors such as age, incontinence, immobility, drug therapy will also have an effect upon a person’s risk of developing PUs.



How do you deal with a Category 4 pressure ulcer on the heels?

It is important to assess the patient’s ability to heal by assessing their peripheral circulation to the area. This may involve a Doppler ABPI or sounding out of pedal pulses and may require the input of a vascular team or Tissue Viability. 

The key here is to assess the patient’s risk of developing pressure ulcers to their heels before it happens and then to offload or “float” the heels to reduce the amount of pressure going through these vulnerable areas. This is especially important for patients with known diabetes, peripheral arterial disease and limb contractures or stiffness of the limbs or joints of the leg, where movement is restricted.

To offload the heels, you could use specialised boots or a turning wedge in the bed or if you have the OSKA Series2 mattress you can use this to offload the heels by using the Heel Offloader feature.  This allows you fold under the top layer of foam to create a wedge at the foot end that then helps to offload the heels.  The Series2 mattress can be used for high-risk prevention of up to Cat 2 treatment and management, but if you have PUs to the heels, you can use the Heel Offloader for up to Cat 4 on the heels only as this acts to offload the heel.  

Specialised heel zones on support surfaces can also assist in reducing the pressure but they do not provide a totally pressure free environment, the key really will be to offload. 

Pillows are never recommended to offload heels as they tend to go flat quickly and therefore the heels sink back into the surface; also pillows provide no pressure reduction to the calves which boots or a wedge will generally do.

Regularly check the heel area using a compact mirror – remember to check under compression hosiery and remove footwear.



At what point do you step a person up to an air mattress?

It’s important to have a good baseline pressure ulcer risk assessment and care plan in place and communicate effectively with the patient about moving onto a more specialised mattress. It helps to explore their knowledge, preferences and any barriers that may arise with change.

Step a patient up to an air mattress as and when their condition changes/ deteriorates, and they become high/ very high risk, or they have developed a Category 3/4 pressure ulcer.  Whenever a patient’s condition changes you should reassess their PU risk and use their risk score along with your clinical judgement to either step a patient up or down.

It’s also important to consider possible future deterioration, such as end of life care. They may start on a foam mattress which can later have a pump added (Series6 OneSurface™), or a dual function mattress which is dynamic and at a later stage could provide lateral tilt and micromovements. 



What comfort level equates to what weight setting on the Series5 & Series6?

On the front of the pump for both the OSKA Series 5 specialist lateral tilt and the OSKA Series6 OneSurface™ is a sticker which shows the weights per comfort setting.