Understanding Pressure Ulcer Formation and Integumentary System Anatomy

Mechanism and Formation of Pressure Ulcers

Many patients are unable to change their positions with ease because of specific physical limitations, including weaknesses, disabilities, or various illnesses. This inability to move or reposition the body without assistance significantly increases the risk for developing a pressure ulcer (PU).

Pressure ulcers form through the following mechanical and physiological process:

  • Pressure Application: Bony areas of the body, referred to as pressure points, press against a mattress, a chair, or another external surface.
  • Tissue Compression: This pressure effectively squeezes the soft tissues located between the bone and the hard surface the person is sitting or lying on.
  • Ischemia: As a result of this compression, blood flow to the tissue is reduced or obstructed.
  • Cellular Death: Without adequate blood flow, the tissue fails to receive essential nutrients and oxygen. Consequently, the cells die.
  • Ulceration: The dead tissue eventually peels off or breaks open, which results in the creation of an open sore or ulcer.

High-Risk Anatomical Locations

Pressure ulcers are most likely to occur over bony areas where the bone is close to the skin surface. These includes:

  • The heels
  • The ankles
  • The knees
  • The hips (specifically the lateral hip or greater trochanter)
  • The toes
  • The elbows
  • The shoulder blades
  • The ears
  • The back of the head
  • Points along the spine
  • The sacrum and coccyx

Statistically, the sacrum and coccyx are the most common sites for pressure ulcer occurrence, followed by the greater trochanter and the heels. The duration of the pressure is a critical factor: the longer a person remains in one single position, the higher the likelihood of a pressure ulcer developing.

Factors and Risk Variables for Pressure Ulcer Development

While continuous pressure is identifies as the primary cause, several other systemic and environmental factors increase vulnerability:

  • Advanced Age: Skin becomes thinner and more fragile with age, and general blood flow to the skin decreases.
  • Poor Nutrition and Lack of Fluids: Adequate fluid intake and high-quality nutrition are essential for maintaining skin health and integrity.
  • Moisture: Prolonged contact with moisture sources such as water, urine, feces, or sweat causes the epidermis to soften and break down.
  • Obesity: Residents or patients with obesity face an increased risk of skin breakdown specifically within skin folds, which tend to trap moisture.
  • Cardiovascular or Respiratory Problems: Medical conditions involving the heart or lungs prevent tissues from receiving sufficient oxygen and nutrients, making the skin more susceptible to damage.
  • Friction and Shearing Injuries: These physical forces can injure the skin and lead to breakdown. Friction is defined as rubbing, while shearing is defined as pulling forces.

Regulatory Standards and Clinical Roles in Pressure Ulcer Management

Because pressure ulcers have serious health consequences, the Omnibus Budget Reconciliation Act (OBRA) expects medical teams to do everything possible to prevent them.

  • Clinical Objective: OBRA requirements focus on improving or maintaining a person's condition. The healthcare team must work to heal existing pressure ulcers and prevent new ones from forming.
  • The Nurse's Responsibilities: The nurse is responsible for conducting formal assessments of each person's risk for pressure ulcers. They must also document any existing pressure ulcers.
  • The Nursing Assistant's (NA) Role: Nursing Assistants help by strictly following the established care plan to mitigate risks.

Wound Care and Healing Processes

Wounds, including pressure ulcers, represent a break in the skin's integrity. Wounds can be caused by various factors:

  • Surgery: Planned medical incisions.
  • Trauma: Unintentional injuries such as car accidents, burns, or falls.
  • Violence: Injuries resulting from being shot or stabbed.

The skin serves as the body's first line of defense against infection. When a wound occurs, it creates an opening for microbes to enter the body, which poses a significant risk for infection. Therefore, it is vital for wounds to heal so that the skin becomes intact and can once again protect the person.

Factors Affecting the Healing Timeline

Several circumstances can delay the body's ability to heal a wound:

  • The presence of multiple simultaneous injuries.
  • Chronic illness.
  • A weakened immune system.
  • Extremes in age (being very old or very young).
  • Poor nutritional status.

The Role of the Nursing Assistant (NA) in Wound Observation

A Nursing Assistant's specific duties regarding wound care will vary based on the protocols of their specific workplace. However, daily responsibilities—even those not directly related to wound care—provide an essential opportunity for the NA to observe pressure ulcers for signs of healing or deterioration.

Anatomy of the Integumentary System

The Integumentary System is the body system that covers the body and includes:

  • The skin
  • Glands
  • Hair
  • Nails

Structural Layers and Components of the Skin

The skin is composed of two primary layers and a supporting layer:

  • Epidermis: The outermost layer of the skin.
  • Dermis: The deepest layer of the actual skin. It contains essential structures including:     - Sensory receptors     - Blood vessels     - Nerves     - Glands     - Hair follicles

The dermis is composed of elastic connective tissue, which allows for stretch and movement without sustaining damage. It also contains melanin, a pigment that protects the skin from exposure to sunlight.

Subcutaneous Tissue and Vascular Support

The dermis rests on a layer of fat known as the subcutaneous tissue. The blood vessels that supply the skin with oxygen and nutrients begin in this subcutaneous tissue and then extend upward into the dermis layer.