7.3 Wounds, Pressure Injuries & Rhabdomyolysis

7.3 Wounds, Pressure Injuries & Rhabdomyolysis

Pressure Injury Staging

The National Pressure Injury Advisory Panel (NPIAP) staging system is tested precisely, and mislabeling a stage is a common error:

The distinguishing line between Stage 3 and Stage 4 is exposed or palpable bone, tendon, or muscle — a wound with visible fat and granulation tissue but no exposed structural tissue stays a Stage 3.

Risk Assessment and Prevention

The Braden Scale is the standard validated tool for pressure-injury risk assessment, scoring six subscales: sensory perception, moisture, activity, mobility, friction/shear, and nutrition. Each subscale is scored (most 1-4, friction/shear 1-3), and lower total scores indicate higher risk — a score at or below the facility's cutoff (commonly 18 or less) triggers escalated prevention protocols.

Core prevention interventions include:

• Scheduled repositioning, generally at least every 2 hours for bed-bound patients (more frequently for higher-risk patients or those without pressure-redistributing surfaces)
• Heel offloading — heels are a very high-risk site given minimal soft-tissue padding over bone
• Pressure-redistributing support surfaces (foam, low-air-loss, or alternating-pressure mattresses) for at-risk patients
• Moisture management — protecting skin from prolonged exposure to urine, stool, or wound drainage
• Adequate nutrition, particularly protein intake, since malnutrition impairs tissue tolerance and wound healing

Wound Types and Negative Pressure Wound Therapy

Beyond pressure injuries, progressive care nurses manage infectious wounds, surgical wounds (including dehiscence and evisceration risk), and traumatic wounds, each requiring wound-bed assessment (tissue type, drainage, odor, periwound skin, signs of infection such as increasing erythema, warmth, purulent drainage, or fever) to guide dressing selection.

Negative pressure wound therapy (NPWT), commonly called wound vac therapy, applies controlled sub-atmospheric pressure to promote granulation tissue formation, reduce edema, and remove exudate. NPWT is contraindicated in:

• Untreated osteomyelitis
• Malignancy within the wound
• Exposed blood vessels, organs, nerves, or anastomotic sites
• Necrotic tissue with eschar present (the wound must be debrided first)
• Unexplored or non-enteric fistulas

Recognizing these contraindications matters clinically — applying NPWT over exposed vasculature, for example, risks catastrophic hemorrhage.

General Wound Care Principles

A few evidence-based principles guide routine wound management regardless of etiology. Moist wound healing promotes faster epithelialization and causes less pain than allowing a wound to dry out. Dressing selection should match exudate volume — absorptive foams or alginates for heavy drainage, moisture-retentive hydrogels for dry wounds — and periwound skin needs protection from maceration and from trauma during dressing removal. Every dressing change is also an opportunity to reassess for infection (increasing pain, spreading erythema, purulent or malodorous drainage, new fever) and escalate beyond routine local care when these signs appear.

Rhabdomyolysis

Rhabdomyolysis is the breakdown of skeletal muscle tissue with release of intracellular contents — most notably myoglobin, creatine kinase (CK), and potassium — into the systemic circulation. Common causes in progressive care patients include crush injury or trauma, prolonged immobility or downtime (including post-surgical positioning), seizures, extreme exertion, and certain medications (notably statins).

Key recognition points:

• Creatine kinase markedly elevated, typically cited as greater than five times the upper limit of normal, is the diagnostic hallmark
• Dark, tea- or cola-colored urine reflects myoglobinuria
• Acute kidney injury is the major complication — myoglobin is directly nephrotoxic and can precipitate in the renal tubules, especially with dehydration or acidic urine
• Hyperkalemia results from the massive release of intracellular potassium and requires close cardiac and lab monitoring

Treatment centers on aggressive isotonic IV fluid resuscitation (typically normal saline) to maintain robust urine output, dilute nephrotoxic myoglobin, and protect renal function, along with vigilant monitoring and treatment of hyperkalemia and trending of CK and renal function. Some protocols incorporate urine alkalinization with sodium bicarbonate, though supporting evidence is mixed, and it should not substitute for adequate fluid volume, which remains the primary intervention.

Wound Bed Assessment and Debridement

Choosing the right dressing starts with correctly characterizing the wound bed. Nurses describe tissue as granulation (healthy, beefy-red, and vascular), slough (yellow, tan, or white nonviable tissue that is soft and stringy), or eschar (black or brown, hard or leathery, fully necrotic tissue) — a wound often contains more than one tissue type at once. Debridement removes nonviable tissue to allow healing and is achieved through several methods: autolytic (the body's own enzymes, supported by a moisture-retentive dressing, slowest but least traumatic), enzymatic (topical debriding agents), mechanical (wet-to-dry dressings, irrigation), and sharp/surgical (fastest, requires a trained clinician). Selecting the correct method depends on the patient's overall condition, wound characteristics, and whether infection is present.

It is also important to distinguish a pressure injury from moisture-associated skin damage (MASD), such as incontinence-associated dermatitis — MASD results from prolonged moisture exposure rather than sustained pressure or shear, typically affects skin folds or the perineal area diffusely rather than over a bony prominence, and is managed with moisture barriers and skin protectants rather than pressure-redistribution alone. Confusing the two can lead to the wrong prevention plan being applied.