11.2 Pressure Prevention, Repositioning, and Support Surfaces

Pressure Prevention, Turning, and Surface Selection

Pressure injury results from the relationship between tissue tolerance, pressure intensity, and pressure duration. A patient who cannot independently shift weight is exposed to longer pressure time over bony prominences. Shear (parallel force that distorts deeper tissue and kinks perfusing vessels) and friction (surface abrasion) compound the risk, and moisture lowers skin resilience. WCC items ask which intervention best reduces the cause of injury, so look for the choice that lowers pressure and shear while supporting inspection and adherence.

The NPIAP/EPUAP/PPPIA Clinical Practice Guideline anchors most prevention reasoning: reposition based on individual risk, tissue tolerance, activity, and the support surface in use; use a standardized risk tool such as the Braden Scale as a structured prompt, not a treatment order; and offload heels completely from the bed surface for at-risk patients. A commonly cited starting repositioning interval is every 2 hours in bed, adjusted to the surface and the person.

Repositioning and Shear Control

Keep the head of bed at 30 degrees or lower when tolerated and clinically permitted to reduce sacral shear, and use the 30-degree lateral tilt rather than full side-lying directly on the trochanter. Avoid dragging the patient up in bed; use a lift sheet or mechanical aid to limit friction and shear. A patient who slides down repeatedly is generating shear that produces deep tissue injury even when the surface looks adequate.

Support Surfaces Are Tools, Not Plans

Surface categories run from reactive (constant low-pressure foam or gel that responds to load) to active/alternating-pressure powered surfaces that cyclically change which areas bear load. The exam will not ask for a brand; it expects you to match the surface to mobility, moisture, weight distribution, current skin status, transfer safety, and setting resources.

Applied example: a long-term-care resident has a high Braden score risk, sits in a recliner most of the day, and develops heel redness. The strongest answer is not simply "order a specialty bed." It is heel offloading, a seating assessment, scheduled weight shifts and repositioning, skin inspection, staff education, and documentation. If moisture or nutrition risks exist, they belong in the same plan.

Prophylactic Dressings and Reassessment

A prophylactic foam dressing over the sacrum or heels can reduce friction and manage microclimate, and guidelines support it as an adjunct for high-risk areas. It does not eliminate pressure, so the plan still needs redistribution and turning. After a surface change, monitor skin response, comfort, transfer safety, and whether the patient can still self-reposition; a surface that traps heat, raises fall risk, or immobilizes the patient creates new problems.

Common Traps

• A powered surface does not make turning unnecessary.
• Do not treat a pressure-redistribution surface as therapy for a wound actually caused by arterial disease, diabetes, or infection.
• Failure to document the risk findings, surface plan, education, tolerance, and reassessment is often the hidden weakness the item is testing, because prevention that is not communicated is not sustained across shifts.

Choosing a Surface by Mobility and Mattress Bottoming Out

A practical decision rule the exam tests: if the patient can independently reposition, a reactive (constant low-pressure) surface plus a structured turning plan is usually adequate. If the patient cannot reposition independently, cannot keep off an existing injury, or has multiple ulcers across turning surfaces, an active alternating-pressure surface is considered. Always check for bottoming out by placing a flat hand, palm up, under the surface beneath the sacrum: if you feel less than about an inch (a fingertip's worth) of support material, the surface is bottoming out and is no longer redistributing pressure.

This single bedside check appears in scenario items because it determines whether the chosen surface is actually working.

Microclimate, Heels, and Sitting Time

Microclimate (skin temperature and moisture at the support interface) influences breakdown; surfaces and dressings that trap heat and sweat raise risk, which is why low-air-loss features and moisture-wicking textiles are considered for sweaty or incontinent patients. Heels deserve a dedicated plan because no general mattress reliably offloads them; suspend the heel with a pillow lengthwise under the calf or a purpose-built heel-suspension boot, keeping the knee slightly flexed to avoid popliteal-vessel compression and foot drop.

For seated patients, limit uninterrupted sitting time and teach weight shifts; prolonged chair sitting concentrates very high pressure on the ischial tuberosities and is a frequent cause of sitting-acquired injuries.

Reassessment Cadence and Escalation

Reassess skin at least each shift in acute care, on a defined schedule in long-term care, and at each visit in home care, plus whenever condition or the surface changes. If a patient develops a new injury despite the current plan, the correct exam action is to escalate the prevention bundle (more frequent turning, a higher-level surface, tighter moisture and nutrition control) and re-examine whether shear or a device is the true cause, not merely to add a dressing over the area.