Pressure Injury Prevention Has Changed. Has Your Mattress Prescription?

For decades, pressure injury prevention was built around one central idea: pressure cuts off blood flow, tissue is starved of oxygen, and skin eventually breaks down. That concept still matters, but it no longer explains the complete picture.

Modern research shows that pressure injuries develop through several biological and mechanical processes working together. Tissue damage may begin within minutes rather than hours, changing how clinicians assess risk and how healthcare support surfaces should be designed and prescribed.

A New Understanding of Pressure Injury Etiology

The traditional ischemia model suggested that sustained pressure blocked blood flow long enough to deprive tissue of oxygen, with damage occurring after six to eight hours.

Today, pressure injury development is understood as the interaction of four contributing mechanisms:

This updated understanding helps explain why pressure injuries can develop during emergency department presentations, patient transport, surgery and other relatively short-duration, high-risk situations.

Risk Assessment Is More Than a Score

Structured assessment tools such as Waterlow, Braden and Norton remain useful, but they capture only a small proportion of the factors that may influence pressure injury risk. Research has identified more than 200 potential risk factors.

Every patient presents with a unique combination of mobility, tissue quality, nutrition, pain, comorbidities, environment and equipment needs. No scoring tool can describe that complete clinical picture.

The Pressure Care Matrix

At Forté Healthcare, support surfaces are considered across four interconnected design factors: pressure, shear, microclimate and mobility.

These factors do not operate independently. Improving one characteristic can affect another, which means effective support surface design requires deliberate trade-offs rather than a single measure of performance.

1. Pressure Redistribution Is About Contact, Not Softness

The objective of pressure redistribution is to increase the area of the body supported by the mattress, reducing peak loading over bony prominences. This is known as envelopment.

When reviewing a pressure map, colour scales can be useful, but the most important question is often simpler: where are the gaps in body contact? Greater contact generally means load is being spread across a larger surface area.

Materials and design methods

• Castellated or zoned foam improves immersion around bony prominences and helps local areas move more independently.
• Memory foam provides excellent redistribution but may restrict mobility when used too deeply. Limiting memory foam comfort layers to approximately 3-4 cm can help preserve movement.
• Static air naturally redistributes load through the path of least resistance, although very immersive air systems may also reduce mobility.

Active and alternating pressure relief

Early alternating air systems commonly used 16 cells, a one-in-two inflation pattern and a six-minute cycle, reflecting the older ischemia-based model.

Newer systems may alternate every third or fourth cell to improve comfort and transfer compliance. Hybrid support surfaces combining static and alternating elements have also become increasingly accepted, with strong outcomes in comfort, compliance and pressure injury prevention.

2. Shear: The Underestimated Risk

Shear occurs when bones move in one direction while the skin remains relatively fixed against the mattress. The soft tissues between them stretch and deform, creating the same cellular damage pathway associated with direct pressure.

Cell death has been observed after surprisingly short periods of sustained shear, and approximately half of pressure injuries occur over the sacrum, where shear forces are especially significant.

Shear can also accumulate unnoticed because the body detects it less effectively than direct pressure. A patient may remain in a damaging position without experiencing the discomfort that would normally prompt movement.

Mitigating shear

• Anti-shear covers use layers that slide internally, reducing the transfer of friction and movement into the skin.
• Four-way stretch covers move with the patient instead of resisting movement.
• Castellated foam reduces surface stiffness and allows local movement with the body.
• Auto-regression beds, where the backrest lifts and moves away simultaneously, remain the gold standard for reducing pelvic migration during elevation.

3. Microclimate: Managing Heat and Moisture

Hot skin is weaker and has a higher nutrient demand at the same time pressure is reducing supply. Wet skin is also more vulnerable to friction, further increasing the impact of shear.

Microclimate risks may be heightened in warm and humid locations, but individual factors such as heaters, electric blankets, fever, sweating and continence also need to be considered.

Airflow is the key intervention

• Vapour-permeable waterproof covers allow moisture vapour to escape while maintaining fluid protection.
• Four-way stretch woven covers combine breathability with the flexibility needed for immersion.
• Foam airflow channels encourage ventilation as the patient moves and repositions.
• Alternating air mattresses are among the most effective options for managing heat and moisture at the support surface interface.

4. Mobility Is Part of Pressure Care

Mobility is often deprioritised in favour of comfort, even in high-specification mattresses. However, a surface that prevents a patient from repositioning independently can increase risk for the patient and create additional handling challenges for caregivers.

Features that support movement

• Firm side rails provide immediate stability for edge sitting and sit-to-stand transfers.
• Response foam provides softness and pressure redistribution while retaining resilience or “bounce”.
• Limited memory foam depth reduces the risk of the patient becoming restricted within the surface.
• Stable mattress geometry supports repositioning, slide sheets and hoist setup.

Pain, Self-Mobilisation and Pressure Risk

One of the body’s most effective pressure injury prevention mechanisms is subconscious repositioning. During sleep, the brain normally prompts movement before discomfort becomes significant.

Pain can override this mechanism. A painful surface may discourage movement, while analgesic medication can reduce the sensation that normally prompts repositioning.

Personalisation Improves Compliance

The most clinically advanced mattress will not deliver its intended outcome if the patient refuses to use it.

Providing a choice between two clinically suitable options can improve acceptance and long-term use. This “Goldilocks effect” gives the patient meaningful control while keeping the prescription within an appropriate clinical framework.

Lifestyle fit also matters. Forcing an older couple into separate beds because a support surface cannot fit their existing arrangement may result in the clinical mattress being removed and the original mattress returning.

Flexible local manufacturing can help address these barriers through custom sizing, colour options and compatibility with specific or heritage bed frames.

What to Check When Prescribing

Looking Beyond the Mattress

Pressure injury prevention is no longer simply about choosing the softest surface or waiting for prolonged ischemia. It requires an understanding of tissue deformation, shear, heat, moisture, mobility and the patient’s real-world environment.

Balancing these factors allows clinicians and equipment prescribers to make more informed decisions and select a support surface that is both clinically appropriate and practical for long-term use.