Skin shearing is a type of skin injury that involves deeper tissue damage, distinct from surface-level friction. This injury often affects individuals who are vulnerable due to limited mobility or other health conditions. Understanding this injury is important for prevention and proper care.
Defining Skin Shearing
Skin shearing occurs when skin remains relatively stationary, but underlying tissues and bone shift in opposing directions. This parallel force stretches and distorts deeper tissue layers, damaging blood vessels and separating skin layers beneath the surface. Shearing differs from friction, a superficial injury from skin rubbing against a coarse surface that affects the epidermis. In contrast, shearing is a “bottom-up” injury impacting deeper structures like the dermis and subcutaneous tissues, leading to more significant internal tissue damage that may not be immediately apparent. Shearing forces are a significant factor in the development of pressure injuries, also known as pressure ulcers or bedsores.
How Shearing Injuries Develop
Shearing injuries commonly develop in situations where an individual’s skin is fixed against a surface while their skeleton or deeper body parts move. For example, when a person slides down in bed, their skin may stick to the sheets, but their bones continue to move downwards due to gravity. This creates a parallel force that stretches and tears the tissue layers. Similar scenarios occur when a person slumps in a chair or is pulled up in bed without being properly lifted. The combination of downward pressure from body weight and the resistance of the skin against a surface causes internal stretching and tearing of blood vessels. This disruption of blood flow can lead to cell death and tissue damage, particularly over bony prominences where pressure is concentrated. Shearing forces can exceed the threshold for potential pressure injury formation during routine activities like repositioning.
Identifying Shearing Damage
Identifying shearing damage can be challenging because the injury often begins in deeper tissue layers before becoming visible on the surface. Initially, the skin might show redness that does not fade when light pressure is applied. Discolored areas, blistering, or skin tears can also be signs of shearing. The damage may appear asymmetrical or ragged, covering a larger surface area as it progresses from deep within the tissue towards the skin’s surface. Shearing can lead to a separation of skin layers, which might manifest as undermining or tunneling beneath the skin. Since the damage starts internally, by the time external signs become apparent, the injury may already be advanced.
Strategies to Prevent Shearing
Preventing skin shearing involves reducing the parallel forces on the skin. Proper repositioning techniques are key; caregivers should lift individuals rather than dragging or pulling them across surfaces. Using assistive devices such as slide sheets, trapeze bars, or mechanical lifts can help facilitate transfers and repositioning without causing shearing.
Maintaining proper posture in beds and chairs is also important to minimize sliding. Keeping the head of the bed at 30 degrees or below can reduce the tendency for a person to slide downward, thereby decreasing shearing forces. Utilizing pressure-redistributing surfaces, such as specialized mattresses or cushions, helps to evenly distribute pressure and allow for slight movement, reducing the risk of tissue distortion. Additionally, selecting low-friction, breathable fabrics for clothing and bedding can prevent the skin from sticking and reduce resistance during movement.
Caring for Sheared Skin
Caring for sheared skin involves promoting healing and preventing further complications. The first step involves a thorough assessment of the injury to determine its extent and severity. Keeping the affected area clean is important to prevent infection; this typically involves gentle cleansing with soap and water or saline solution. Protecting the injured skin from additional trauma is also important. This might include applying appropriate dressings to cover the wound and using padding to offload pressure from bony prominences. Given the deeper nature of shearing injuries, seeking professional medical advice for proper diagnosis and treatment is essential. Early intervention can help manage the injury effectively and reduce the risk of it progressing to a more severe pressure injury.