6.1 Skin Integrity, Pressure Injury Prevention & Mobility

Skin Integrity, Pressure Injury Prevention & Mobility

Preserving skin integrity and promoting safe physical mobility represent foundational responsibilities for Patient Care Technicians (PCTs) and clinical support personnel. The skin is the human body's largest organ, serving as a primary immunological barrier against pathogen invasion, regulating core temperature, and preventing fluid loss. When immobility, sensory deficits, malnutrition, or systemic disease compromise this cutaneous shield, patients face catastrophic complications—including deep soft tissue necrosis, osteomyelitis, sepsis, and extended hospitalization.

Preventing cutaneous breakdown demands a rigorous understanding of the biomechanical forces that compromise microcirculation, structured clinical assessment using standardized instruments such as the Braden Scale, precise staging according to National Pressure Injury Advisory Panel (NPIAP) guidelines, and meticulous adherence to safe transfer and range-of-motion protocols.

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1. Pathophysiology and Etiology of Pressure Injuries

A pressure injury is defined as localized damage to the skin and underlying soft tissue, usually over a bony prominence or related to a medical or other device. The injury occurs as a result of intense and/or prolonged pressure, or pressure combined with shear.

The Biomechanical Forces: Pressure, Shear, Friction & Moisture

Tissue destruction results from four interrelated physical mechanisms:

1. Sustained Mechanical Pressure: Normal microvascular capillary pressure ranges between 20 and 32 mmHg. When external compressive forces exceed this capillary closing pressure, the lumen of microvessels collapses. Blood flow ceases, depriving surrounding cells of oxygen and essential nutrients while allowing toxic metabolic waste products to accumulate. If compression persists without relief, microvascular thrombosis occurs, resulting in localized cellular hypoxia, tissue ischemia, and irreversible necrosis.
2. Shear Forces: Shear occurs when two layers of tissue slide in opposing directions across each other. In clinical practice, shear is most commonly generated when a patient in bed has the head of the bed (HOB) elevated greater than 30 degrees. Gravity pulls the skeleton and deep fascial layers downward toward the foot of the bed, while the cutaneous epidermis and dermis remain fixed against the bedsheets due to friction. This divergent sliding force stretches, kinks, angulates, and tears the perforating microvessels supplying the subcutaneous fat and dermis, rapidly generating deep subcutaneous tissue necrosis that may not initially be visible on the skin surface.
3. Friction: Friction represents the mechanical resistance encountered when skin rubs against another surface, such as bedsheets, chair cushions, or medical equipment. Friction abrades and strips away the protective superficial stratum corneum, creating painful micro-erosions and "sheet burns." While friction alone does not cause deep pressure injuries, it destroys the epidermal moisture barrier, accelerating tissue vulnerability to shear and microbial invasion.
4. Moisture and Maceration: Prolonged contact with moisture—derived from urinary incontinence, fecal incontinence, wound drainage, or diaphoresis (excessive sweating)—softens and weakens connective tissue proteins. This process, known as maceration, transforms the epidermis into a friable, waterlogged, white or pale tissue that erodes under minimal friction or pressure. Fecal incontinence is exceptionally destructive because enteric digestive enzymes (lipases, proteases) chemically digest cutaneous lipids and proteins, shifting skin pH from its normal acidic mantle (pH 4.5–5.5) toward an alkaline state that fosters rapid bacterial and fungal colonization.

Bony Prominences at Greatest Clinical Risk

Pressure injuries develop predominantly where subcutaneous adipose tissue is minimal and bone lies in close proximity to the cutaneous surface:

• Supine Position: Sacrum, coccyx, calcaneus (heels), olecranon (elbows), inferior angles of the scapulae, and the occiput.
• Lateral Side-Lying Position: Greater trochanter of the femur, lateral and medial malleoli (ankles), acromion process (shoulder), and lateral ear pinna.
• Prone Position: Patellae (knees), anterior superior iliac spines, forehead, sternum, and dorsal toes.
• Seated / Chairbound Position: Ischial tuberosities ("sit bones"), coccyx, sacrum, and posterior aspects of the knees.

[External Mechanical Loading]
              |
              v
[Tissue Compression > 32 mmHg] ---> [Capillary Occlusion]
              |                               |
              v                               v
[Deep Shear & Vascular Tearing]       [Ischemia & Hypoxia]
              |                               |
              +-------------------------------+ 
                              |
                              v
                  [Cellular Necrosis & Slough]

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2. Risk Assessment: The Braden Scale

The Braden Scale for Predicting Pressure Sore Risk is the most widely validated and utilized clinical instrument in acute and long-term healthcare environments. It systematically evaluates six clinical subscales representing physiological and environmental risk factors.

The Six Braden Subscales

Each subscale is scored from 1 (most impaired / highest risk) to 4 (normal / no impairment), with the exception of Friction and Shear, which is scored from 1 to 3:

1. Sensory Perception (1 to 4): Measures the ability to feel and respond meaningfully to pressure-related discomfort. Patients who are completely comatose, heavily sedated, or paralyzed (paraplegia, quadriplegia) score 1; patients with no sensory deficits score 4.
2. Moisture (1 to 4): Quantifies the degree to which skin is exposed to moisture. Skin that is constantly moist from unmanaged urinary/fecal incontinence or diaphoresis scores 1; skin that is rarely moist scores 4.
3. Activity (1 to 4): Measures physical ambulation capabilities. Completely bedbound patients score 1; patients who walk frequently outside their rooms score 4.
4. Mobility (1 to 4): Assesses the patient's capacity to adjust and control body position independently. Completely immobile patients who cannot make even slight positional adjustments without human assistance score 1; patients with complete, unrestricted mobility score 4.
5. Nutrition (1 to 4): Evaluates habitual dietary intake patterns. Patients with very poor oral intake (eating less than one-third of meals, receiving inadequate IV hydration, or NPO for > 5 days) score 1; patients who eat most of every meal and consume adequate protein score 4.
6. Friction and Shear (1 to 3): Evaluates physical handling and sliding. A score of 1 indicates a significant problem (requires moderate-to-maximum assistance during moves, slides constantly in bed); a score of 3 indicates no apparent problem (moves independently in bed and chair with sufficient muscle strength to lift clear of contact surfaces).

Scoring Interpretation and Clinical Cutoffs

The total Braden score ranges from a minimum of 6 to a maximum of 23. Lower numerical scores indicate greater clinical impairment and higher risk for pressure injury development:

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3. NPIAP Pressure Injury Staging Criteria

The National Pressure Injury Advisory Panel (NPIAP) classifies pressure injuries according to the anatomical depth of soft tissue destruction. Accurately staging a pressure injury guides nursing care, debridement protocols, and advanced wound dressing selection.

Stage 1: Non-Blanchable Erythema of Intact Skin

• Clinical Presentation: Intact skin with a localized area of persistent, non-blanchable erythema (redness). Non-blanchable means that when light fingertip pressure is applied to the reddened area for 3 seconds, the skin remains red and does not turn white (blanch).
• Assessment in Darkly Pigmented Skin: In patients with deeply pigmented skin, blanching may not be visible. Instead, the technician must look for localized discoloration that differs from the surrounding skin (appearing persistently purplish, bluish, darker brown, or ashen gray). The area may also be painful, firm, soft, warmer, or cooler compared to adjacent tissue.
• Tissue Depth: Cellular distress is concentrated in the epidermis and superficial microvasculature. No skin break is present.

Stage 2: Partial-Thickness Skin Loss with Exposed Dermis

• Clinical Presentation: Partial-thickness loss of skin with exposed dermis. The wound bed is viable, pink or red, and moist. Stage 2 injuries may also present as an intact or ruptured/open serum-filled blister.
• Crucial Exclusions: Adipose (subcutaneous fat) is NOT visible. Granulation tissue, slough, and eschar are NOT present. This stage does not describe moisture-associated skin damage (MASD), intertrigo, or skin tears.

Stage 3: Full-Thickness Skin Loss

• Clinical Presentation: Full-thickness loss of skin in which subcutaneous adipose (fat) tissue is visible within the ulcer crater. Granulation tissue (pink, healthy, pebbled connective tissue) and epibole (rolled wound edges) are commonly present.
• Necrotic Tissue: Slough (yellow, tan, gray, or brown soft fibrinous debris) and/or eschar (firm, leathery, brown or black necrosis) may be visible, but must not obscure the base of the wound.
• Undermining and Tunneling: Depth may include undermining (tissue destruction extending beneath the intact wound margins) and tunneling (narrow tracts extending into underlying tissue).
• Crucial Exclusions: Fascia, muscle, tendon, ligament, cartilage, and bone are NOT exposed or directly palpable.

Stage 4: Full-Thickness Skin and Tissue Loss

• Clinical Presentation: Full-thickness skin and tissue loss with directly exposed or palpable fascia, muscle, tendon, ligament, cartilage, or bone.
• Wound Bed Features: Slough and eschar are frequently present on parts of the wound bed. Epibole, extensive undermining, and deep sinus tracts/tunneling are common. Because bone is directly exposed, osteomyelitis (bone infection) represents an imminent clinical threat.

Unstageable Pressure Injury: Obscured Full-Thickness Loss

• Clinical Presentation: Full-thickness skin and tissue loss in which the actual extent of tissue damage within the ulcer base cannot be confirmed because it is completely obscured by slough or eschar.
• Debridement Rationale: Until enough slough (yellow, tan, gray) or eschar (tan, brown, black) is mechanically, chemically, or surgically removed to visualize the wound bed base, the true stage (Stage 3 or Stage 4) cannot be determined.
• The Heel Eschar Exception: Stable, dry, intact, non-fluctuant, non-erythematous eschar on the calcaneus (heel) serves as the body's natural, physiological biological cover and must NOT be removed or softened. The heel has minimal subcutaneous fat and poor vascularity; debriding stable heel eschar opens a direct portal for osteomyelitis.

Deep Tissue Pressure Injury (DTPI): Persistent Non-Blanchable Discoloration

• Clinical Presentation: Intact or non-intact skin exhibiting persistent, non-blanchable, localized deep red, maroon, or purple discoloration, or epidermal separation revealing a dark wound bed or blood-filled blister.
• Pathophysiology: DTPI results from intense pressure and shear forces occurring at the bone-muscle interface, causing deep tissue ischemia that subsequently progresses upward toward the skin surface. The area is often preceded by tissue that is painfully boggy, firm, mushy, warmer, or cooler than adjacent skin. A DTPI may rapidly evolve to reveal the actual extent of tissue injury, deteriorating into a full-thickness Stage 3 or Stage 4 ulcer even under optimal treatment.

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4. Evidence-Based Prevention Strategies

Preventing pressure injuries requires continuous, proactive clinical vigilance. Once tissue ischemia begins, cellular necrosis can develop in as little as two hours.

Turning and Repositioning Schedules

• Bedbound Patients: Must be repositioned at least every 2 hours around the clock. An individualized turning clock or schedule (e.g., left lateral tilt, supine, right lateral tilt) should be documented at the bedside.
• Chairbound / Wheelchair Patients: High pressures are concentrated directly over the ischial tuberosities during upright sitting. Seated patients must be taught to shift their weight every 15 minutes if physically capable. If the patient is dependent, the technician must reposition or return the patient to bed at least every 1 hour.

The 30-Degree Lateral Tilt Position

When positioning a patient on their side, avoid placing them at a full 90-degree angle directly on the hip. A 90-degree lateral position directs the patient's entire upper body weight onto the greater trochanter of the femur, causing rapid trochanteric breakdown. Instead, place the patient in a 30-degree lateral tilt position, placing pillows behind the back and between the knees to distribute weight across the fleshy gluteal musculature while sparing the trochanter.

Head-of-Bed (HOB) Elevation Limits

Except during meals, nasogastric tube feedings, or acute dyspnea, the head of the bed must be maintained at 30 degrees or less. Elevating the bed to 45 or 60 degrees causes the patient to slide downward, generating intense sacrococcygeal shearing forces that tear deep perforating microvasculature.

Floating the Heels (Heel Offloading)

The calcaneus has minimal subcutaneous cushioning and represents the second most common pressure injury site. Technicians must float the heels completely off the mattress surface by placing pillows lengthwise beneath the patient's calves (from below the knees to above the ankles).

• Crucial Rule: Never place a pillow directly beneath the Achilles tendon or heel, as this merely transfers the concentrated pressure point to the tendon. The heels must remain suspended in open air. Alternatively, specialized heel-suspension boots with open heel cutouts should be applied.

Moisture and Incontinence Management

• Inspect skin during every hygiene encounter and incontinence episode.
• Cleanse skin immediately following incontinence episodes using warm water and a gentle, no-rinse, pH-balanced perineal cleanser. Avoid harsh alkaline bar soaps and avoid aggressive mechanical scrubbing.
• Apply a moisture barrier ointment or cream containing zinc oxide, petrolatum, or dimethicone to shield the perianal and sacral skin from moisture and digestive enzymes. Apply moisture barrier film (skin protectant wipes) over bony prominences subject to friction.
• Use breathable, absorbent underpads. Never place folded plastic-backed "chux" or heavy linens beneath the patient, as they trap heat and humidity.

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5. Range of Motion (ROM) & Mobility Support

Immobility causes rapid muscular atrophy, joint stiffness, and joint contractures—permanent shortening of muscle fibers and tendons that freezes joints into flexed deformities. Systematic Range of Motion (ROM) exercises maintain joint flexibility, enhance circulation, and stimulate lymphatic drainage.

Modalities of Range of Motion

• Active Range of Motion (AROM): The patient independently moves all joints through their full physiological arc of motion using their own muscular strength without physical assistance.
• Passive Range of Motion (PROM): The patient is unable to move their joints independently (due to coma, paralysis, profound weakness, or sedation). The PCT physically supports and moves each joint through its full available arc of motion without active assistance from the patient.
• Active-Assistive Range of Motion (AAROM): The patient possesses partial muscular strength but requires manual assistance from the technician or an assistive device to complete the joint arc.

Critical Rules of PROM Execution

1. Support Proximally and Distally: When moving a joint, the technician must cradle and support the extremity both proximally (above the joint) and distally (below the joint) using broad, cupped hands. Never grasp fragile fingers or pull on joint capsules.
2. Never Force Past Resistance: Move each joint smoothly, gently, and rhythmically. Move the joint only to the point of slight resistance or patient-reported discomfort. Never force a joint past resistance or pain. Forcing can tear spastic muscle fibers, rupture tendons, dislocate joint capsules, or fracture demineralized bones.
3. Repetitions: Perform each designated movement 3 to 5 times per session, repeating the exercise routine at least twice daily or as prescribed in the nursing care plan.

Essential Joint Movement Terminology

• Flexion: Bending a joint to decrease the angle between two adjacent bones (e.g., bending elbow).
• Extension: Straightening a joint to increase the angle between bones up to anatomical position (e.g., straightening elbow).
• Hyperextension: Extending a joint beyond its normal anatomical position (e.g., tilting head backward).
• Abduction: Moving an extremity laterally away from the midline of the body.
• Adduction: Moving an extremity medially toward the midline of the body.
• Pronation: Rotating the forearm so the palm of the hand faces downward or posteriorly.
• Supination: Rotating the forearm so the palm of the hand faces upward or anteriorly ("holding a cup of soup").
• Circumduction: Moving an extremity in a continuous circular cone-like motion combining flexion, abduction, extension, and adduction.
• Dorsiflexion: Flexing the ankle so that the foot and toes pull upward toward the anterior shin.
• Plantarflexion: Pointing the ankle and toes downward toward the floor ("planting the foot").
• Internal (Medial) Rotation: Turning a bone or extremity inward toward the central axis of the body.
• External (Lateral) Rotation: Turning a bone or extremity outward away from the central axis of the body.

          [Dorsiflexion: Toes Upward]
                     ^
                     |
[Plantarflexion: Toes Downward] <--- [Ankle Joint] ---> [Inversion / Eversion]

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6. Safe Transfer Mechanics & Ambulation Support

Improper patient handling constitutes the leading cause of debilitating musculoskeletal injuries among healthcare workers. Utilizing sound biomechanical principles protects both the clinician and the patient during transfers.

Core Principles of Body Mechanics

• Base of Support: Maintain a wide base of support by placing feet shoulder-width apart, with one foot slightly forward to enhance anteroposterior stability.
• Center of Gravity: Keep the load as close to the body's center of gravity (pelvis/abdomen) as possible. Lifting with outstretched arms exponentially multiplies spinal lumbar load.
• Lift with Legs, Never the Back: Bend deeply at the hips and knees while maintaining the natural anatomical curvature of the spine. Engage the large, powerful quadriceps and gluteal muscles to lift. Never bend forward at the waist with straight knees.
• Pivot, Never Twist: When turning with a patient, pivot on the balls of the feet by taking small stepping turns. Never twist or rotate the torso while bearing a load; spinal rotation under axial compressive stress herniates intervertebral discs.

Transfer Gait Belt Mechanics

A gait belt (transfer belt) is a heavy canvas or nylon belt that provides secure handholds when assisting unsteady patients with transfers and ambulation.

• Application: Apply the belt snugly around the patient's natural waistline over clothing. Never apply a gait belt over bare skin, surgical incisions, colostomy stomas, or chest tubes. Check tightness: exactly two flat fingers should fit comfortably between the belt and the patient's body.
• Grip Technique: The technician must grasp the gait belt using an underhand (supinated) grip with both hands positioned on either side of the patient's spine. An underhand grip provides far superior leverage and biomechanical stability compared to an overhand (pronated) grasp.
• Bed-to-Wheelchair Transfer Technique:
  1. Position the wheelchair at a 45-degree angle to the bed on the patient's stronger (unaffected) side.
  2. Lock the brakes on both the bed and the wheelchair, and swing the footrests out of the way.
  3. Lower the bed so the patient's feet rest flat and firmly on the floor.
  4. Assist the patient to a sitting position on the edge of the bed ("dangling") and assess for orthostatic dizziness.
  5. Apply the gait belt snugly around the waist.
  6. Stand directly in front of the patient, bracing the patient's weaker knee and foot with your own knees and feet.
  7. On the count of three, rock forward, using your leg muscles to assist the patient into a standing position.
  8. Pivot toward the wheelchair, having the patient reach back and grasp the wheelchair armrests before slowly lowering down into the seat.

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7. Clinical Scenarios & Practice Traps

Bedside Scenario: The Sinking Patient

A technician enters the room of an 82-year-old bedbound patient recovering from a stroke. The head of the bed is elevated to 60 degrees because family members were visiting, and the patient has slid downward so their feet are pressing against the footboard. The sacral area shows a patch of purple-maroon skin that is boggy and painful.

• Clinical Trap: Assuming that elevating the head of the bed provides comfortable resting, and simply pulling the patient up in bed by grasping the patient under the axillae.
• Pathology: Sitting at 60 degrees caused severe gravitational shear, tearing the deep subcutaneous arterioles over the sacrum and generating a Deep Tissue Pressure Injury (DTPI). Pulling the patient under the arms causes shoulder subluxation and severe friction/shear on the back.
• Correct Action: Lower the head of the bed flat (or ≤ 30 degrees). Use a friction-reducing slide sheet with two caregivers lifting together to reposition the patient up in bed. Position the patient in a 30-degree lateral tilt, float the heels, and alert the registered nurse immediately to evaluate and document the sacral DTPI.

Bedside Scenario: The Black Heel Eschar

A technician is bathing an elderly patient with severe peripheral arterial disease and notices that both calcaneal heels have hard, dry, black, intact, leather-like eschar with no redness, drainage, or odor. The technician considers soaking the feet in warm water and applying moisturizing ointment to "soften and loosen" the black scabs.

• Clinical Trap: Attempting to soften, soak, or debride dry, stable, intact heel eschar.
• Pathology: Stable eschar on the heel is the body's natural sterile biological dressing over an area with almost no vascular supply. Soaking or softening the eschar converts dry gangrene into wet gangrene, fostering bacterial proliferation that tracks directly into the calcaneus, resulting in osteomyelitis and limb amputation.
• Correct Action: Leave the intact, dry, non-fluctuant eschar alone. Do not soak or apply moisture. Elevate the lower legs on pillows to keep the heels completely floated off the bed surface, and notify the nurse.