Among the following, the factor that contributes to pressure ulcer is?

AIIMS Bhuvneshwar NO- 2018

Medical Surgical Nursing

Medium

Appeared in: AIIMS Bhuvneshwar NO- 2018

Explanation

Shearing force is a direct mechanical cause of pressure injuries, distinct from predisposing risk factors.
It occurs when tissue layers slide against each other, such as when a patient slides down in bed.
This movement stretches, angulates, and tears blood vessels deep within the tissue, leading to ischemia and necrosis.
Unlike friction which affects the epidermis, shear causes damage at a deeper fascial level over bony prominences.

Option A: Chronic diseases like diabetes or vascular disease are systemic risk factors that impair circulation and healing, increasing susceptibility to pressure injuries, but they are not a direct mechanical force causing the injury.
Option B: Malnutrition, particularly low protein levels, is a major predisposing risk factor. It weakens tissue integrity and the body's ability to repair damage, but it is not a direct mechanical cause.
Option C: Edema (swelling) makes the skin more fragile and reduces tissue perfusion, which increases the risk of breakdown from pressure or shear. However, it is a contributing condition, not the direct mechanical force itself.

Visual 1: Diagram - An illustration comparing the forces of pressure, shear, and friction on the skin and underlying tissue layers. This helps clarify how shear causes deep damage while friction is superficial.
Visual 2: Infographic - The Braden Scale for Predicting Pressure Sore Risk, highlighting the 'Friction and Shear' subscale to emphasize its clinical importance in risk assessment.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Pathophysiology and risk factors for pressure injuries as background academic context rather than a clinical decision trigger.
Nurses play a critical role in preventing pressure injuries by identifying at-risk patients using tools like the Braden Scale and implementing targeted interventions.
A key nursing intervention to prevent shear is to limit the elevation of the head of the bed to 30 degrees or less and to use a lift sheet when repositioning patients instead of dragging them.
Patient and family education should include instructions on frequent repositioning and recognizing early signs of skin breakdown.

How to Approach the Question

First, understand the question is asking for a factor that contributes to pressure ulcers. All options are related, so you need to find the most direct cause.
Differentiate between direct mechanical causes and indirect risk factors. Mechanical causes are forces that physically damage the tissue (pressure, shear, friction).
Analyze the options: Chronic disease, malnutrition, and edema are conditions that make the body more vulnerable to injury (risk factors).
Identify 'Shearing forces' as a direct mechanical force that damages tissue by stretching and tearing blood vessels.
Conclude that shearing force is the most appropriate answer as it represents a primary mechanism of injury, whereas the others are predisposing conditions.

Concept Tested & Keywords

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