Scientific Knowledge Base

Question 1

Skin

Answer 1

The epidermis, or the top layer, has several layers. The stratum corneum is the thin outermost layer of the epidermis. It consists of flattened, dead, keratinized cells. The cells originate from the innermost epidermal layer, commonly called the basal layer. Cells in the basal layer divide, proliferate, and migrate toward the epidermal surface. After they reach the stratum corneum, they flatten and die. This constant movement ensures replacement of surface cells sloughed during normal desquamation or shedding. The thin stratum corneum protects underlying cells and tissues from dehydration and prevents entrance of certain chemical agents. The stratum corneum allows evaporation of water from the skin and permits absorption of certain topical medications. The dermis, the inner layer of the skin, provides tensile strength; mechanical support; and protection for the underlying muscles, bones, and organs. It differs from the epidermis in that it contains mostly connective tissue and few skin cells. Collagen (a tough, fibrous protein), blood vessels, and nerves are found in the dermal layer. Fibroblasts, which are responsible for collagen formation, are the only distinctive cell type within the dermis.
Focus on Older AdultsSkin-Associated Issues
When caring for the older adult there are several skin-related issues to consider when assessing skin and risk for skin breakdown. Age-related changes such as reduced skin elasticity, decreased collagen, and thinning of underlying muscle and tissues cause the older adult’s skin to be easily torn in response to mechanical
trauma, especially shearing forces. The attachment between the epidermis and dermis becomes flattened in older adults, allowing the skin to be easily torn in response to mechanical trauma (e.g., tape removal). Existing medical
conditions and polypharmacy are factors that interfere with wound healing. Aging causes a diminished inflammatory response, resulting in slow epithelialization and wound healing.

Question 2

Pressure Injuries aka Pressure injury, pressure ulcer, decubitus ulcer, and bedsore.

Answer 2

Ulcer cannot be present without injury but injury can be present without an ulcer.
Ulcer - break in skin or mucus membrane - with loss of surface tissues. Injury is bodily damaged caused by transfer of energy. “can you easily change position?” “can you feel heat or cold?” “how often do you go to toilet?”
A pressure injury is localized damage to the skin and underlying soft tissue, usually over a bony prominence or related to a medical device or other device. The injury can present as intact skin, a blister, or an open ulcer and may be painful. The injury occurs as a result of intense and/or prolonged pressure or pressure in
combination with shear (Edsberg et al., 2016). The tolerance of soft tissue for
pressure and shear may also be affected by microclimate, nutrition, perfusion, comorbidities,
and condition of the soft tissue.
Any patient experiencing decreased mobility, decreased sensory perception, fecal or
urinary incontinence, and/or poor nutrition is at risk for pressure injury
development. Examples of patients who are at risk for the development of pressure
injuries include the following:
• Older adults, those who have experienced trauma
• Those with spinal-cord injuries (SCI)
• Those who have sustained a fractured hip
• Those in long-term homes or community care, the acutely ill, or those in a
hospice se􀄴ing
• Individuals with diabetes
• Patients in critical care se􀄴ings. Pressure is a major cause of injury. Tissue receives oxygen and nutrients and
eliminates metabolic wastes via the blood. Pressure or other factors that interfere
with blood flow in turn interfere with cellular metabolism and the function or life of
the cells. Prolonged, intense pressure affects cellular metabolism by decreasing or
obliterating blood flow, resulting in tissue ischemia and ultimately tissue death.Pressure is the major element in the cause of pressure injuries.

pressure itself is the number one target factor to cause pressure injury development….

1) PRESSURE INTENSITY
2) PRESSURE DURATION 3)TISSUE TOLERANCE