Can a deep tissue injury present with blanchable characteristics?

Deep Tissue Injury and Blanchability: Clinical Characteristics and Differentiation

Deep tissue injuries (DTIs) are not blanchable, as they originate in deeper tissues and present with purple or maroon discoloration that does not blanch when pressure is applied.

Understanding Deep Tissue Injury

Deep tissue injury is a serious type of pressure injury that begins in the muscle closest to the bone and may not be visible in its early stages. It is characterized by:

• Purple or maroon localized area of discolored intact skin
• Blood-filled blister due to damage of underlying soft tissue from pressure and/or shear
• Rapid deterioration despite appropriate preventive interventions 1
• Non-blanchable appearance due to extravasated blood in the tissues 2

Distinguishing Characteristics of DTI

Clinical Presentation

• Presents as purple or maroon discoloration in light-skinned individuals
• Has a defined border around the area of injury
• Often surrounded by erythema 2
• In dark-skinned individuals, persistent erythema and hyperpigmentation rather than blanching should be used to determine pressure injury 2
• May rapidly evolve to expose additional layers of tissue even with optimal treatment 3

Pathophysiology

DTI develops through two primary mechanisms:

1. Direct deformation damage: Results from high strains that lead to cell damage within minutes
2. Ischemic damage: Caused by occlusion of blood vessels, developing over several hours 4

Differential Diagnosis from Blanchable Conditions

When assessing a potential DTI, it's crucial to differentiate it from conditions that may appear similar but are blanchable:

• Stage 2 pressure injuries: These involve partial-thickness loss of dermis and may present as shallow open ulcers with a red-pink wound bed that is typically blanchable 3
• Incontinence-associated dermatitis: Often blanchable erythema
• Venous engorgement: May present with purple discoloration but typically blanches
• Bruising: May appear similar but has different history and progression pattern 2

Assessment Approach

To properly identify a DTI and distinguish it from blanchable conditions:

1. Thorough history: Document exposure to pressure, such as "time down" at the scene or periods when the patient was immobile 2
2. Blanching test: Apply gentle pressure to the area and release - DTIs will not blanch
3. Visual examination: Look for purple/maroon discoloration with defined borders
4. Monitor progression: DTIs often deteriorate rapidly despite preventive measures 1

Clinical Implications and Management

• Early identification is critical as DTIs can rapidly progress to more severe stages
• Implement turning schedules every 2-4 hours for high-risk patients 3
• Use specialized support surfaces to reduce pressure on affected areas 3
• Ensure adequate nutrition (30-35 kcal/kg/day and 1.25-1.5 g protein/kg/day) to support healing 3
• Regular assessment of wound characteristics to monitor progression 3

Common Pitfalls in DTI Assessment

• Mistaking DTI for a blanchable condition, leading to inadequate intervention
• Failing to recognize DTI in dark-skinned individuals where discoloration may be less obvious
• Neglecting to assess for biofilm formation in wounds 3
• Inadequate pressure redistribution, which can accelerate DTI progression 3

By understanding that deep tissue injuries are fundamentally non-blanchable due to their pathophysiology involving deep tissue damage and extravasated blood, clinicians can more accurately identify and appropriately manage these serious pressure injuries.