Necrosis of the Skin (Pressure Ulcers)
Overview
Pressure‑related skin necrosis, commonly called pressure ulcers or bedsores, is localized damage to the skin and underlying tissue caused by prolonged pressure, shear, or friction. Necrosis indicates that a portion of the tissue has died. While anyone can develop a pressure ulcer, the condition overwhelmingly affects people who are immobile for long periods—such as patients hospitalized in intensive‑care units, residents of long‑term‑care facilities, and individuals with spinal‑cord injuries or advanced neuro‑degenerative diseases.
According to the U.S. Centers for Disease Control and Prevention (CDC), up to 2.5 million adults develop pressure ulcers each year in the United States, and they are reported in 12–14 % of hospitalized patients and up to 30 % of long‑term‑care residents. In low‑ and middle‑income countries, prevalence may be even higher due to limited access to pressure‑relieving equipment.1 Early detection and prompt treatment are crucial, because once necrosis sets in the wound can progress rapidly to infection, sepsis, or even death.
Symptoms
Pressure ulcers are staged by the depth of tissue involvement (Stage I–IV) and may present with the following signs and symptoms:
- Stage I (non‑blanchable erythema): Intact skin that appears red (or purple in darker skin tones) and does not turn white when pressed. The area may feel warm, cool, or painful.
- Stage II (partial‑thickness loss): A shallow open ulcer or a blister (intact or ruptured) that reveals pink or red granulation tissue.
- Stage III (full‑thickness loss): Loss of skin down to the subcutaneous fat. The ulcer appears as a deep crater; the edges may be rolled or undermined.
- Stage IV (full‑thickness loss with tissue necrosis): Exposure of muscle, tendon, or bone; often accompanied by black, necrotic tissue (eschar) and foul odor.
- Unstageable ulcer: Full‑thickness loss is covered by slough (yellow‑white) or eschar that obscures the depth; the wound must be debrided to stage accurately.
Additional symptoms that may accompany any stage include:
- Pain or tenderness, which may be absent in later stages when nerves are destroyed.
- Swelling, warmth, or a feeling of tightness around the wound.
- Redness or discoloration extending beyond the visible ulcer.
- Foul odor, indicating bacterial colonization or infection.
- Systemic signs such as fever, chills, or increased heart rate if infection spreads.
Causes and Risk Factors
Pressure ulcers arise when external forces exceed the capacity of skin and underlying tissue to maintain adequate blood flow. The primary mechanisms are:
- Prolonged pressure: Direct compression of capillaries (>32 mm Hg) for >2 hours reduces oxygen delivery.
- Shear forces: Sliding of skin over bony prominences stretches and tears blood vessels.
- Friction: Repeated rubbing damages the epidermis.
- Moisture: Incontinence‑associated dermatitis weakens skin integrity.
Key risk factors include:
- Immobility (bedridden, wheelchair‑bound, prolonged surgery).
- Reduced sensation (e.g., spinal cord injury, peripheral neuropathy, stroke).
- Age ≥ 65 years (skin thins with age).
- Chronic conditions that impair circulation or wound healing (diabetes, peripheral arterial disease, chronic kidney disease, malnutrition, anemia).
- Low serum albumin (< 3.5 g/dL) or BMI < 18.5 kg/m².
- Incontinence or excessive sweating.
- Smoking, which decreases microvascular blood flow.
- Medications that limit mobility or impair healing (steroids, immunosuppressants).
Diagnosis
Diagnosis is clinical, supported by a systematic skin assessment and, when needed, adjunctive tests.
Step‑by‑step assessment
- Visual inspection: Examine all bony prominences (sacrum, coccyx, heels, hips, elbows, knees, shoulder blades) on admission and at least every 24 hours for at‑risk patients.
- Palpation: Gently press to assess blanchability and tenderness.
- Staging: Classify the ulcer using the National Pressure Injury Advisory Panel (NPIAP) criteria (Stage I–IV, unstageable, deep tissue injury).
- Photographic documentation: Standardized photos aid monitoring.
Laboratory and imaging studies
- Wound culture: Indicated if there are signs of infection (purulent discharge, increased pain, odor). Swab cultures are less reliable; tissue biopsy is preferred.
- Blood tests: CBC, C‑reactive protein (CRP), erythrocyte sedimentation rate (ESR), serum albumin, and glucose to identify systemic infection or healing barriers.
- Imaging:
- X‑ray: Detects underlying osteomyelitis or foreign bodies.
- MRI: Gold standard for early detection of bone involvement.
- CT scan: Helpful when MRI is contraindicated.
Treatment Options
Management is multidisciplinary and aims to (1) relieve pressure, (2) promote a moist wound‑healing environment, (3) eradicate infection, and (4) address systemic factors that impede healing.
Pressure‑relieving measures
- Repositioning: Turn or shift the patient at least every 2 hours (bed) or every 15–30 minutes (wheelchair) using a documented schedule.
- Support surfaces: Use alternating‑pressure mattresses, low‑air‑loss devices, or specialized cushions for heels and sacrum.
- Shear reduction: Employ draw sheets, side rails, and proper lifting techniques.
Wound‑care modalities
- Debridement: Removal of necrotic tissue is essential.
- Mechanical (wet‑to‑dry dressings), enzymatic, autolytic (hydrocolloid), or sharp surgical debridement.
- Dressings: Choose based on exudate level and stage.
- Hydrocolloid or foam for moderate exudate.
- Alginate or charcoal dressings for heavily exudative wounds.
- Transparent film for superficial, low‑exudate ulcers.
- Negative‑pressure wound therapy (NPWT): Applies controlled suction, promoting granulation tissue and reducing edema; especially useful for Stage III–IV ulcers.
- Advanced biologics: Collagen matrices, acellular dermal matrix, or recombinant growth‑factor products (e.g., becaplermin) may accelerate healing in selected cases.
Infection control
- Topical agents: Silver‑impregnated dressings, iodine, or honey for mild colonization.
- Systemic antibiotics: Indicated for clinical infection or osteomyelitis; choose agents based on culture sensitivities (e.g., vancomycin for MRSA, piperacillin‑tazobactam for polymicrobial infections).
Systemic and supportive therapies
- Optimise nutrition: 25–30 kcal/kg/day, protein 1.2–1.5 g/kg/day, vitamin C, zinc, and adequate fluids.
- Control glycaemic levels (< 180 mg/dL) in diabetic patients.
- Manage anemia (target Hb ≥ 10 g/dL) and albumin (< 3.5 g/dL) with supplementation as needed.
- Smoking cessation programs.
Surgical options
When conservative measures fail, surgical reconstruction may be required:
- Flap coverage (muscle, fasciocutaneous, or free tissue transfer) for extensive tissue loss.
- Skin grafts (partial‑ or full‑thickness) after thorough debridement.
- Amputation – a last resort for irreversible necrosis with uncontrolled infection.
Living with Necrosis of the Skin (Pressure Ulcers)
Daily self‑care and lifestyle adjustments can dramatically improve healing and quality of life.
- Skin‑check routine: Inspect at‑risk areas each day. Use a mirror or ask a caregiver for hard‑to‑see spots.
- Repositioning schedule: Set alarms or use a repositioning‑reminder app to ensure timely turns.
- Maintain a clean, dry environment: Use barrier creams for incontinence, change linens promptly.
- Nutrition: Incorporate high‑protein foods (lean meat, eggs, legumes), vitamin‑rich fruits/vegetables, and consider a protein supplement if intake is inadequate.
- Hydration: Aim for 1.5–2 L of fluid daily unless contraindicated.
- Exercise within limits: Passive range‑of‑motion exercises improve circulation.
- Follow wound‑care instructions: Keep dressings clean, change them as directed, and report any increase in drainage or odor.
- Stay connected with the care team: Attend regular wound‑clinic appointments, and report setbacks promptly.
Prevention
Most pressure ulcers are preventable with systematic risk‑assessment and timely interventions.
- Risk‑assessment tools: Use the Braden Scale or Norton Scale on admission and reassess at least weekly.2
- Pressure‑relieving devices: Provide appropriate mattresses, cushions, and heel protectors for high‑risk patients.
- Repositioning protocol: Turn schedule (2‑hourly) documented in the nursing chart.
- Skin care regimen: Gentle cleansing with pH‑balanced products, moisturise dry skin, and apply barrier ointments where moisture is excessive.
- Nutrition and hydration: Screen for malnutrition on admission; involve a dietitian early.
- Education: Train patients, families, and staff on early signs of pressure damage.
- Mobility promotion: Physical therapy to encourage safe transfers and ambulation whenever possible.
Complications
If left untreated, pressure ulcers can lead to serious, potentially life‑threatening conditions:
- Infection: Local cellulitis, abscess formation, or progression to osteomyelitis.
- Sepsis: Systemic inflammatory response; mortality rates exceed 20 % in severe cases.3
- Chronic pain: Neuropathic or nociceptive pain affecting daily activities.
- Scarring and contractures: Limiting joint range of motion.
- Reduced quality of life: Depression, social isolation, and increased caregiver burden.
- Amputation: In extreme necrosis with uncontrolled infection.
When to Seek Emergency Care
- Rapid increase in wound size or depth, especially if black, foul‑smelling tissue appears.
- Fever ≥ 38 °C (100.4 °F), chills, or a rapid heart rate together with wound changes.
- Severe pain that suddenly worsens or is unrelieved by prescribed analgesics.
- Signs of systemic infection such as confusion, low blood pressure, or decreased urine output.
- Pus or drainage that suddenly becomes profuse, watery, or foul‑smelling.
- Loss of sensation around the ulcer accompanied by swelling, indicating possible deep tissue infection.
References:
All information is for educational purposes and does not replace professional medical advice. Consult your health‑care provider for personalized diagnosis and treatment.