What strategies should be used to reduce friction and shear in immobile critical‑care patients to prevent pressure injuries?

Reducing Friction and Shear in Immobile Critical Care Patients

For immobile critical care patients at risk of pressure injuries, use advanced static mattresses or overlays as the primary intervention to reduce friction and shear forces, combined with systematic repositioning, proper skin care, and moisture management as part of a bundled prevention strategy. 1

Primary Intervention: Support Surface Selection

The most critical decision for reducing friction and shear is selecting the appropriate support surface:

• Use advanced static mattresses or advanced static overlays for all high-risk immobile critical care patients (strong recommendation, moderate-quality evidence) 1
• These surfaces reduce pressure injury incidence compared to standard hospital mattresses and are cost-effective
• Avoid alternating-air mattresses or overlays as they show no clear benefit over static surfaces and add unnecessary cost (weak recommendation against) 1

Why This Matters

Pressure injuries result from pressure alone or pressure combined with shear forces 1. Shear stress occurs when horizontal forces cause bony prominences to move across tissue while skin remains fixed, particularly during patient movement or bed adjustments 2. Advanced static surfaces conform to bony prominences without resistance, allow patient immersion, and help relieve shear caused by patient movement 3.

Essential Bundled Interventions

1. Risk Assessment

• Perform systematic risk assessment using validated tools (Braden, Norton, Cubbin and Jackson, or Waterlow scales) 1
• Reassess regularly as patient condition changes
• High-risk factors include: immobility, sensory loss, malnutrition, incontinence, obesity, and hemodynamic instability 1, 4

2. Repositioning Strategies

• Reposition patients every 2 hours as standard practice 4, 5
• Use 30-degree lateral tilt positioning rather than 90-degree side-lying to minimize pressure over bony prominences 6
• For ventilated patients: maintain 30-60 degree upper body elevation to reduce VAP risk, though note this increases decubitus risk at 45 degrees versus 30 degrees 7
• Critical caveat: Use proper lifting and turning techniques to avoid dragging patients, which dramatically increases shear forces 2

3. Skin and Moisture Management

• Inspect high-risk areas during each repositioning (sacrum, heels, occiput, scapulae) 7, 4
• Use skin cleansers other than soap and apply fatty acid-containing creams (low-quality evidence shows benefit) 1
• Manage incontinence aggressively to prevent moisture-related skin breakdown 1
• Consider protective dressings for bony prominences, though evidence is limited 1

4. Nutritional Optimization

• Address malnutrition and hypoalbuminemia as these impair tissue integrity 1
• Provide adequate protein and caloric support
• Note: Evidence for specific nutritional supplementation preventing pressure injuries is mixed 1

Special Considerations for Critical Care

Prone Positioning (ARDS patients)

• Carefully examine pressure-prone areas during prone positioning to minimize pressure injury risk 7
• Position head centrally and avoid lateral rotation to prevent increased intracranial pressure 7
• Prone positioning should be complete (180 degrees) when indicated for respiratory benefit 7

Medical Device-Related Pressure Injuries

• These are increasingly recognized in critical care settings 5
• Secure devices (endotracheal tubes, feeding tubes, catheters, monitoring equipment) to prevent friction and pressure
• Regularly reposition or pad devices that contact skin

Hemodynamically Unstable Patients

• Vasopressor use is not a contraindication to repositioning or prone positioning 7
• Stabilize volume status before major position changes when possible 7

Implementation Approach

Step 1: Identify all immobile patients using risk assessment tools
Step 2: Place on advanced static mattress/overlay immediately
Step 3: Implement 2-hour repositioning schedule with 30-degree lateral tilts
Step 4: Establish skin inspection protocol at each turn
Step 5: Optimize nutrition and manage moisture/incontinence
Step 6: Monitor and document adherence to prevention bundle

Common Pitfalls to Avoid

• Dragging patients during repositioning: This is the primary cause of shear injury. Always lift, never drag 2
• Assuming expensive alternating-air surfaces are better: Evidence does not support this, and they waste resources 1
• Neglecting heels: These are high-risk areas requiring specific offloading strategies 1
• Inconsistent repositioning: Adherence to routine repositioning remains suboptimal in practice (78.6-90.4% in recent data) 8
• Focusing only on pressure: Shear forces are equally damaging and require specific mitigation through proper handling techniques and appropriate surfaces 2

Evidence Strength and Gaps

The strongest evidence supports advanced static surfaces (moderate quality) 1. Evidence for specific repositioning intervals, nutritional interventions, and dressings remains low quality 1. However, the absence of high-quality evidence for standard care practices (repositioning, skin care, nutrition) does not mean these should be abandoned—they remain fundamental to prevention 1.

Recent data shows HAPI prevalence remains at 3.8% despite widespread prevention efforts 8, indicating that consistent implementation of evidence-based bundles, particularly nutritional support and repositioning, requires improvement across acute care settings.