Prep U: Ch 4: Cell Proliferation and Tissue Regeneration and Repair

Which client is at greatest risk for decreased wound healing?

An adult client with type 1 diabetes and an infection in the foot

Explanation: Any client with an autoimmune disease (e.g., diabetes) is at greater risk for decreased wound healing because the healing process relies on the immune reaction. Diabetes mellitus is also a condition that impairs inflammation and immune function. Many clients with diabetes have wounds that do not respond well to traditional methods of wound treatment because of their high blood glucose levels. None of the other clients has an increased risk for poor wound healing.

When caring for a client with a wound that is healing by primary intention, the nurse recognizes which characterization best describes this type of wound?

surgical incision

explanation: A sutured surgical incision is an example of healing by primary intention. Larger wounds (e.g., burns and large surface wounds) or wounds purposely left open due to infection heal by secondary intention.

The nurse is caring for a client with an accumulation of 2.5 cm of darkened tissue scar over the area of a 3-mm injury. How does the nurse correctly document this finding in the medical record?

keloid

explanation: Keloids are tumor-like masses caused by excess production of scar tissue. The tendency toward development of keloids is more common in blacks and seems to have a genetic basis.

What function does hyaluronic acid (a component of the extracellular matrix) performs in the body?

Lubricates joints and serves as a supportive structure in the extracellular space throughout the body.

explanation: Water-hydrated gels (e.g., proteoglycans and hyaluronic acid) permit resilience and lubrication (of joints, skin, etc.). Fibroblasts are responsible for the synthesis of collagen, elastic, and reticular fibers. Fibroblast growth factors are potent regulators of cell proliferation, differentiation and function and are critically important in normal development, tissue maintenance and wound repair. The laminin family of glycoproteins are an integral part of the structural scaffolding in almost every tissue of an organism. They are secreted and incorporated into cell-associated extracellular matrices. Laminin is vital for the maintenance and survival of tissues. Defective laminins can cause muscles to form improperly, leading to a form of muscular dystrophy.

While explaining to a young child why he should be careful with a wound, the nurse reviews healing with the parent. The nurse educates the parent about how strength in the healing wound site is developed based on which substance being available?

Collagen synthesis

Explanation:
Collagen synthesis is important to the development of strength in the healing wound site. Plasma, exudate, and stable cells do not give strenth to the healing tissue.

The nurse caring for a postoperative client documents that the surgical incision is healing by:

Primary intention

Select the option that best describes why highly differentiated neuron cells are unable to increase their numbers after a certain point in time.

The stimuli to bring about mitosis are lacking.

Explanation: As a cell becomes more highly specialized, the stimuli that are able to induce mitosis become more limited. Neurons, which are highly specialized cells, lose their ability to proliferate once the development of the nervous system is complete. Stem cells can differentiate into neurons but are not the reason proliferation stops. Growth factor is involved in tissue repair not proliferation. Parent cells are not involved in neuron cell proliferation.

The nurse is evaluating the wounds of four clients. Select the client most likely to be treated with hyperbarically delivered oxygen.

An infected foot wound on a 45-year-old client with peripheral vascular disease

Which condition is an example of wound healing by secondary intention?

An infected burn of the arm

Which client would likely benefit the most from hyperbaric oxygen therapy?

A trauma client who developed Clostridium spp., an anaerobic bacterial infection in the femur

Explanation: Hyperbaric oxygen is a treatment that has demonstrated improved wound healing in multiple types of injuries. It enhances wound healing by a number of mechanisms, including the increased killing of bacteria by neutrophils, impaired growth of anaerobic bacteria, and the promotion of angiogenesis.

The nurse caring for a client with a large leg wound notes that the client's past medical history includes diabetes, chronic atrial fibrillation, asthma controlled by maintaninence medication, and neuropathy. Which one has the greatest potential to negatively impact the healing of the client's wound?

Diabetes

Explanation: The client's diabetes has the greatest potential to negatively impact the client's wound healing as this places the client at risk for delayed wound healing and infection from hyperglycemia.

When caring for a client during the proliferative phase of wound healing, the nurse teaches the client that which of these processes is taking place?

Fibroblasts secrete collagen for wound healing.

When caring for a client with a pressure ulcer, the nurse collaborates with the provider to obtain an order for which of these interventions to promote wound healing?

Keep dressing of the wound bed moist.

Explanation: Because epithelial cell migration requires a moist vascular wound surface and is impeded by a dry or necrotic wound surface, the wound should be kept moist. Compression or pressure can impede wound healing. Vitamin C is necessary for wound healing rather than potassium, which is necessary for cardiac function.

Select the statement that best describes stem cells.

Undifferentiated cells of continuously dividing tissues that have the capacity to generate multiple cell types

Explanation: Stem cells are undifferentiated cells of continuously dividing tissues that have the capacity to generate multiple cell types. Labile cells, such as the epithelial cells of the skin and gastrointestinal tract, are those that continue to regenerate throughout life. Stable cells, such as those in the liver, are those that normally do not divide but are capable of regeneration when confronted with an appropriate stimulus. Permanent or fixed cells are those that are unable to regenerate.

While studying for a pathophysiology exam on cells and tissue repair, a student asks, "What happens if, in the process of going through the cell cycle, a cell is damaged?" Which is the best response?

There are built-in checkpoints in the cell cycle to allow for defects to be edited and repaired.

While reviewing the phases of wound healing, the students note that the first cells to arrive after the injury are the:

neutrophils.

Explanation: The cellular phase of inflammation follows and is evidenced by the migration of phagocytic white blood cells that digest and remove invading organisms, fibrin, extracellular debris, and other foreign matter. The neutrophils arrive within minutes and are usually gone by day 3 or 4. They ingest bacteria and cellular debris. Within 24 to 48 hours, macrophages, which are larger phagocytic cells, enter the wound area and remain for an extended period. These cells, arising from blood monocytes, are essential to the healing process. The final component of the proliferative phase is epithelialization, which is the migration, proliferation, and differentiation of the epithelial cells at the wound edges to form a new surface layer that is similar to that destroyed by the injury.

The nurse is caring for a client with a chronic wound. The most important intervention for the nurse to include in the plan of care would be:

Vitamin C and zinc supplements

Explanation: Vitamins play an essential role in the healing process. Vitamin C is needed for collagen synthesis. Zinc has been found to aid in re-epithelialization. Vitamin C and zinc supplements are often ordered for clients with chronic wounds to promote wound healing. Steroid therapy would decrease wound healing. A diet high in proteins and carbohydrates would be ordered to promote wound healing.

Tissues are composed primarily of cells in the M phase.

False

Explanation: Tissues may be composed primarily of quiescent cells in the G0 phase. The M phase is the phase during which cell mitosis occurs.

When caring for a postoperative client, in order to promote wound healing, which of these nutrients does the nurse encourage the client to consume?

Vitamin C

Explanation: Vitamins are essential cofactors for the daily functions of the body; vitamins A and C play an essential role in the healing process. Vitamin C is needed for collagen synthesis. Vitamin K plays an indirect role in wound healing by preventing bleeding disorders that contribute to hematoma formation and subsequent infection. Proteins, fats, carbohydrates and microminerals such as zinc are required for wound healing as well.

The nurse is assessing the wound of a postoperative client. The client has a 6-inch abdominal wound that is well approximated and closed with surgical suture. The wound does not display any redness or drainage. The nurse would document the healing process as:

primary intention

explanation: A sutured surgical incision is an example of healing by primary intention. Secondary intention is slower than healing by primary intention and results in the formation of larger amounts of scar tissue. Tertiary intention is a wound that is open and needs to be closed when granulation tissue forms. There is not a progressive intention.

After many years of cigarette smoking, a client is admitted to have a "mass" removed from the lung. When explaining the surgery and recovery, the physician notes that the client is likely to have a good amount of fibrosis develop at the surgical area. After the physician leaves the room, the client asks the nurse what was meant by "fibrosis" in the lung. The nurse bases the response on the fact that tissue repair can:

result in replacement tissue in the form of connective (fibrous) tissue, which leads to scar formation or fibrosis of the lung.

A client with a torn rotator cuff has been asked by his physician, a regenerative specialist, to consider allowing transplantation of his own stem cells into his area of injury. This is an example of:

therapeutic cloning.

Following a severe automobile accident, a client is scheduled to have surgery to either repair or remove his spleen, pancreas, and stomach. The client wants the organs repaired and not removed if at all possible. However, the nursing staff understands that extensive regeneration in parenchymal organs can only occur if:

the residual tissue is structurally and functionally intact.

Explanation: Regeneration can occur in parenchymal organs with stable cell populations but, with the exception of the liver, is usually a limited process. It should be pointed out that extensive regeneration can occur only if the residual tissue is structurally and functionally intact. If the tissue is damaged by infection or inflammation, regeneration is incomplete and accomplished by replacement with scar tissue.

While educating a group of individuals about to undergo knee surgery, the nurse stresses the importance of eating a well-balanced diet, especially high in vitamins. Which vitamin promotes collagen synthesis to facilitate the wound to the knee to heal properly?

Vitamin C

Explanation: Vitamin C is needed for collagen synthesis. In vitamin C deficiency, improper sequencing of amino acids occurs, proper linking of amino acids does not take place, the by-products of collagen synthesis are not removed from the cell, new wounds do not heal properly, and old wounds may pull apart. Vitamin A functions in stimulating and supporting epithelialization, capillary formation, and collagen synthesis. Vitamin K plays an indirect role in wound healing by preventing bleeding disorders that contribute to hematoma formation and subsequent infection.

A client with diabetes has an admission hemoglobin A1c (HbA1c) level of 13 (goal is 6) and an abdominal wound that will not heal. The nurse knows that hyperglycemia (poor blood glucose control) has an effect on wound healing, especially related to neutrophils affecting:

ability to engulf and kill bacteria because of poor phagocytic function.

A client with a large decubitus ulcer asks the nurse, "How it is possible for a wound this deep to ever fully heal?" What is the nurse's best response?

With adequate resources, the body is capable of regenerating tissue and blood flow to the area over time.

Explanation: Even large wounds can heal over time given adequate blood and nutritional supply. The formation of early granulation tissue is one of the more rapid phases; the subsequent healing by secondary intention takes much longer. Surgery may be required, but this is not true for all large wounds. Telling the client there are experts planning the care does not address the client's question and is dismissive.