7.1 Positioning, Bed Mobility, & Pressure Injury Prevention

Positioning, Bed Mobility, & Pressure Injury Prevention

Proper positioning, bed mobility, and pressure injury prevention are fundamental components of restorative nursing care and are heavily tested on both the written and manual skills portions of the Utah Certified Nursing Assistant (CNA) exam. As a nursing assistant, you are the primary defense against the development of debilitating skin breakdown.

The Physiology of Pressure Injuries

A pressure injury, also historically referred to as a decubitus ulcer or pressure sore, is localized damage to the skin and underlying soft tissue, usually over a bony prominence. This damage occurs as a result of intense, prolonged pressure, or pressure combined with shear. When a resident lies or sits in one position for too long, the weight of the body compresses the blood vessels against the hard surface of the bed or chair, obstructing the flow of oxygen and nutrients to the tissue. If pressure is not relieved, the tissue dies (necrosis), leading to painful, slow-healing wounds that put the resident at high risk for systemic infection (sepsis).

Critical Risk Factors

• Immobility: Residents who cannot move or reposition themselves independently.
• Incontinence: Moisture from urine or feces weakens the skin, making it more susceptible to breakdown (maceration).
• Poor Nutrition & Hydration: Inadequate protein and fluid intake impairs tissue integrity and healing.
• Sensory Deficits: Residents with neuropathy or dementia who cannot feel discomfort or communicate the need to turn.

Shearing vs. Friction

It is vital to distinguish between two mechanical forces that damage skin during repositioning:

1. Friction: The mechanical force exerted when skin rubs against a coarse surface, such as bed linens. This can scrape off the outer layer of skin (epidermis).
2. Shear: A gravity-based force exerted when the skin remains stationary against a surface (like the sheet) while the underlying bone and muscle slide downward. This occurs when the head of the bed is elevated, causing the resident to slide down. Shear stretches and tears the deep blood vessels, causing severe deep-tissue damage.

Exam Trap: When moving a resident up in bed, never drag them across the sheets. Dragging causes friction and shear. Always use a draw sheet (lift sheet) and coordinate with another caregiver to lift and slide the resident.

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Pressure Injury Staging Reference Table

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Repositioning Schedules and Clinical Guidelines

Under federal OBRA regulations and Utah Administrative Rules (R432-45-5), nurse assistants must adhere strictly to individualized care plans. The baseline clinical standard is:

• Bed-bound residents: Must be repositioned at least every 2 hours.
• Chair-bound residents: Must be repositioned or have their weight shifted at least every 15 minutes.
• Skin Inspection: CNAs must inspect the resident's skin at every turning cycle, paying special attention to bony prominences: occiput (back of head), ears, scapulae (shoulder blades), sacrum (tailbone), coccyx, hips, elbows, knees, ankles, and heels.

The Standard of Offloading Heels

The heels are highly vulnerable to pressure injuries because they have minimal subcutaneous fat protecting the calcaneus bone. To prevent breakdown, CNAs must perform offloading heels (commonly called "floating heels"). This is done by placing a pillow lengthwise under the resident's calves. The pillow must lift the heels completely off the mattress, ensuring that no pressure is applied to the heels.

Clinical Warning: Never place a pillow directly under the heels, as this concentrates pressure on the heels. The pillow must support the lower legs (calves) so that the heels "float" in the air.

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Anatomical Positions for Bed Mobility

The Utah CNA skills exam testing guidelines require precise execution of positioning techniques. You must maintain the resident's proper body alignment (keeping the spine straight) and support their limbs with pillows as specified.

1. Supine Position

In the supine position, the resident lies flat on their back.

• Supportive Pillows:
  1. Under the head and shoulders (preventing neck flexion).
  2. Under the calves to float the heels.
  3. Under the arms/hands if the resident has weakness or contractures.
  4. Optionally, a footboard or rolled towel can prevent foot drop (a plantar flexion contracture where the foot falls forward).

2. Lateral Position (Side-Lying)

In the lateral position, the resident lies on their side.

• Supportive Pillows:
  1. Under the head and neck.
  2. Behind the back (tucked lengthwise to prevent the resident from rolling backward).
  3. Between the knees and ankles (cushioning bony contact and maintaining hip alignment).
  4. Under the upper arm to support the shoulder and keep the arm level with the chest.

3. Prone Position

In the prone position, the resident lies flat on their abdomen with the head turned to one side. This position is rarely tolerated by elderly residents due to cardiovascular and respiratory restrictions, but it may be used to promote hip extension.

• Supportive Pillows:
  1. Under the head (small pillow).
  2. Under the abdomen (to prevent hyperextension of the lumbar spine).
  3. Under the lower legs/shins (to elevate the toes off the mattress and keep the knees slightly flexed).

4. Fowler’s Positions

In Fowler's position, the resident is semi-upright with the head of the bed elevated. This position is crucial for residents with respiratory distress (dyspnea) or those eating to prevent aspiration.

• Semi-Fowler's: Head of bed is elevated 30 to 45 degrees.
• Fowler's (Standard): Head of bed is elevated 45 to 60 degrees.
• High-Fowler's: Head of bed is elevated 60 to 90 degrees.
• Supportive Pillows: Under the head, under the knees (slight flexion to prevent sliding), and under the forearms.

5. Sims’ Position (Semi-Prone)

The Sims' position is a specialized left side-lying position. The resident lies on their left side with the right knee and thigh drawn up toward the chest. The left arm is positioned behind the body. This position is primarily used for administering enemas, rectal medications, or taking rectal temperatures.

• Supportive Pillows:
  1. Under the head.
  2. Under the flexed right arm.
  3. Under the flexed right leg/knee to keep it level with the hip and prevent pressure on the lower leg.

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Step-by-Step Skill Execution: Turning a Resident to a Side-Lying Position (UNAR Skill Check)

1. Initial Steps: Knock, identify the resident, explain the procedure, wash hands, and pull privacy curtains.
2. Safety Steps: Raise the bed to a comfortable working height. Ensure the side rail on the side the resident is turning toward is raised, or stand on the opposite side.
3. Move Resident in Three Segments: Before turning, move the resident closer to the side of the bed opposite the turn direction. Slide hands under the head/shoulders, then the torso/hips, and finally the legs. This ensures the resident remains in the center of the bed after the turn.
4. The Turn: Cross the resident's arms over their chest and cross the leg further from the turn direction over the closer leg. Place one hand on the resident's shoulder and the other on their hip, and gently roll them away from you.
5. Positioning Pillows: Place a pillow behind the back, folding it in half to tuck it snugly. Place a pillow between the legs, ensuring the knee and ankle are fully supported and not rubbing together. Place a pillow under the upper arm. Verify the resident is not lying on their lower arm.
6. Closing Steps: Lower the bed to its lowest position. Place the call light in the resident's hand. Wash hands and document.

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Teaching Focus: Positioning That Protects Skin

When teaching families or reinforcing care-plan instructions, emphasize that every turn is a skin check. Look and feel for warmth, coolness, firmness, or color change over the sacrum, hips, heels, elbows, and scapulae. Keep sheets smooth and dry; wrinkled linens create friction points. Elevate the head of the bed only as ordered—prolonged high Fowler's increases sacral shear as the resident slides toward the foot of the bed. Use pillows to keep bony areas from touching each other, and document the time of each reposition so the two-hour and fifteen-minute standards are met consistently.