Prevention of pressure ulcers

This page provides a concise summary of the best available knowledge on pressure ulcers and their prevention

If you want to read more
the references appear at the bottom of the page.

What are pressure ulcers

Pressure ulcers are the result of persistent pressure or shear of the skin and underlying tissues – typically in places on the body where the bones are close to the skin and where there is little fat.
Pressure occurs when a person’s weight is pressed down against the ground. Whether the person is lying, sitting or standing, the pressure is transmitted to the underlying tissue and the tissue is compressed between the surface and the bone. Muscle tissue does not tolerate as much pressure as skin. Therefore, the damage will occur close to the bone and often only be visible on the skin 1-2 weeks after it has been exposed to pressure.
Shear causes torsion, which damages tissues and blood vessels. This means that less pressure is needed to reduce blood flow to the injured area. Therefore, pressure damage to tissues exposed to shear will occur more quickly.
Pressure is caused by failure to change position or external pressure from, for example, medical equipment such as oxygen and catheters.
Shear occurs when the body is moved without being lifted off the ground. This can happen, for example, when a person sits with a raised headboard and slides into bed.
Pressure is reduced when it is distributed over a larger area. This can be achieved with good foam mattresses, frequent position changes and pillows and mattresses with stationary air. Levabo offers this, and our range of pressure relieving products can help you prevent and treat pressure ulcers effectively and gently.

The most pressurised places on the body

The sacrum is the most typical site, followed by the ischium and the heels.

Overweight people often get pressure sores on their heels due to the increased weight of their legs.

Underweight people often get pressure ulcers on the sacrum due to lack of subcutaneous fat padding.

Pressure ulcers can also typically occur on upper extremities at the elbows and shoulders; on the back at the spine and shoulder blades; at the iliac crest, tailbone, on the buttocks; on lower extremities at the knees, knee caps, calves and ankles; on toes; on the back of the head, ears and nose.

30 degree side positioning

Some of the most important elements in preventing pressure ulcers are using a proper support under the person at risk of developing pressure ulcers; making frequent position changes and/or turns in bed. It remains important when a pressure ulcer has occurred and needs to be treated.
A side lying position, like the one Turn All provides, of 30 degrees alternating between right and left side, reduces the external pressure noticeably compared to if a person lies in back lying position or is placed directly in side lying position in bed.
A randomized controlled trial by Moore et al. show that a 30-degree lateral tilt that places the user in a side-lying position with side changes every three hours, compared to a 90-degree lateral tilt that places the user in a side-lying position with side changes every six hours, significantly reduced the incidence of pressure ulcers by more than 70% in 28 days.
The angle of inclination in the lateral position is thus a relevant risk factor for the development of pressure ulcers. A 30 degree lateral tilt is advantageous compared to a backrest or a 90 degree lateral tilt. With a 30 degree tilt, direct support surface pressure is avoided for most bone projections.

Pressure ulcers in children

There are no Danish figures on the extent of pressure ulcers in children, but international studies indicate that up to 75% of hospitalised children have pressure ulcers.
The vast majority of pressure injuries in children are related to the use of medical devices that are fixed to children as part of treatment or life support. These include peripheral venous catheters, ventilation equipment and plaster casts. But also bearing-related pressure injuries on the head, heels and ears occur frequently.
Bearing injuries typically occur during surgical procedures or prolonged immobilisation combined with a medical condition that increases the risk of developing pressure injuries. It could be compromised circulation or high fever, for example.

Risk factors for pressure injuries in children are;

  • Immobility
  • Prematurity
  • Reduced perception (for example due to loss of consciousness, medication and paralysis)
  • Critical illness
  • Use of medical equipment

Who is at risk of developing pressure ulcers

  • Overweight
  • Underweight
  • Acute and critically ill
  • Older
  • Bedridden
  • People with spinal cord injury
  • People with diabetes
  • Palliative persons
  • Children (especially due to medical equipment)
  • Persons with reduced functional capacity

The four categories of pressure ulcers

Kategori 1: Intakt hud med rødme.
Intakt hud med rødme som ikke ændrer farve når man trykker med en finger på området (manglende kapillærrespons). Smertefuldt. Hyppigst over et knoglefremspring.
Kategori 2: Delvist hudtab
Delvist hudtab der viser sig som et overfladisk sår med en rød sårbund uden dødt væv. Kan også forekomme som intakt eller bristet vabel. Smertefuldt.
Kategori 3: Fuldhudstab
Fuldhudstab hvor der kan ses subkutant fedt, men ikke sener, knogler eller muskler. Der kan ses dødt væv (nekrotisk) i sårbunden. Smertefuldt.
Kategori 4: Dyb vævsskade
Fuldt vævstab med blottede sener, knogler eller muskler som er følbare eller synlige. Der kan ses dødt væv (nekrotisk) eller arvæv i sårbunden. Typisk ingen smerter.

Guidelines for job changes

The National Clinical Guidelines for the Prevention of Pressure Ulcers recommend the following essential interventions during position change and encampment:
Frequency of position changes is assessed based on observation of skin condition; nutritional status of the patient/resident; whether the patient/resident has poor circulation; whether the patient/resident has impaired sense of touch; ability of the patient/resident to perform position changes independently; and type of mattress. The more risk factors, the more frequently a change of position is needed.
The frequency of position changes can be modified if changes in the skin are observed – if pressure is observed, the frequency increases, and conversely if pressure is no longer observed, the frequency of position changes may be reduced.
Use 30 degree side positioning
Maximum weight-bearing surface bearing, where the bearing material supports the entire body surface, for stability and neutral bearing pattern.
Position change can be done with frequent micromobilisation
Involving the patient/citizen in risk and communicating prevention knowledge to him/her should be done as early as possible and at all stages of a prevention programme and when developing a camp plan.
Factors such as sleep disturbance, pain, patient/resident preferences, and the overall treatment goal are of significant importance in choosing the method of encampment and selecting the frequency of position changes.


Wounds & wound care - A basic book in nursing Bermark,S.,Melby,B.Ø.(ed.),2017.FADL.

Most pressure ulcers are preventable Lindholm,C.,Sommer,C.,Fremmelevholm,A.,2018.Fag & Forskning.,Trialog 4,p.22-35.

Prevention and treatment of pressure ulcers/pressure injuries. Main excerpts from the guideline European Pressure Ulcer Advisory Panel (EPUAP),National Pressure Injury Advisory Panel (NPIAP), Pan Pacific Pressure Injury Alliance (PPPIA),2019.

Mobility and immobility Knygle Hansen,B.,Dam Schmidt,R.,2011.Chapter 11,in: Suhr,L.K.,Winther,B.(Ed.),Basisbog i nursing - body and well-being.Munksgaard Denmark,Copenhagen,p.311-344.

A randomised controlled clinical trial of repositioning, using the 30° tilt, for the prevention of pressure ulcers Moore,Z.,Cowman,S.,Conroy,R.M.,2011.Journal of Clinical Nursing.20,2633-2644.

Pressure ulcers: Prevention and management Mervis,J.S.,Phillips,T.J.,2019.Journal of the American Academy of Dermatology.81,893-902.

Pressure injuries in children are underreported Søgaard,K.,Sørensen,J.A.,2020.Ugeskrift for Læger.182.

National Clinical Guideline for the Prevention of Pressure Ulcers in Adults Over 18 Skovgaard,B.,Secretariat,Working Group,2020.Sundhedsstyrelsen.