Factors Affecting Wound Healing

Age
The physiological changes that occur with aging place the older patient at higher risk of poor wound healing. Reduced skin elasticity and collagen replacement influence healing. The immune system also declines with age, making older patients more susceptible to infection. Older people can also present with other chronic diseases, which affect their circulation and oxygenation to the wound bed.

 

 

Dehydration
Dehydration leads to an electrolyte imbalance and impaired cellular function. It is a particular problem in patients with burns and fistulae.

 


Hand Washing
Effective hand washing greatly reduces the risk of transferring pathogenic organisms from one patient to another by direct contact or by contamination of inanimate objects that are shared.

 


Infection
Infection has been defined as the deposition and multiplication of organisms in tissue with an associated host reaction. If the host reaction is small or negligible, then the organism is described as colonizing the wound rather than infecting it. It is important to distinguish between colonization and infection since colonized wounds will heal without the need for antibiotics (Cutting 1994).


Contamination is the deposition and survival, but not the multiplication, of the organism (Ayton 1985).


Wound infection is a problem because, at the most fundamental level, infection stops a wound from healing by:

  • Prolonging the inflammatory phase
  • Disrupting the normal clotting mechanisms
  • Promoting disordered leukocyte function and ultimately preventing the development of new blood vessels and formation of granulation tissue.

 

Assessment of a wound in order to identify wound infection should not be limited to swabbing the wound for bacteriological analysis.


Infection occurs when virulence factors expressed by one or more microorganisms in a wound out-compete the person's immune system. Subsequent invasions and spread of microorganisms in good tissue provokes a series of local and systemic responses such as:

 

Surgical (acute wounds)

  • Local pain / tenderness
  • Local swelling / edema
  • Increased exudates, either serous or purulent or serosanguinous
  • Separation of wound edges/wound breakdown
  • Pyrexia
  • Delayed healing

 

Chronic wounds

  • Delayed healing
  • Increased fragility or change in appearance of granulation tissue
  • Unexpected pain / tenderness
  • Pocketing or bridging of epithelial tissue
  • An abnormal smell
  • Presence of exudate either serous or purulent or serosanguinous
  • Local swelling / edema
  • Extending margin or erythema
  • Pyrexia
  • Wound breakdown

 

Medication
Anti-inflammatory, cytotoxic, immunosuppressive, and anticoagulant drugs all reduce healing rates by interrupting cell division or the clotting process.

 

Oxygenation and tissue perfusion:

  • Good wound oxygenation is essential for wound healing. Oxygen influences angiogenesis, epithelialization, and resistance to infection
  • Discourage smoking

 

Personal and oral hygiene

  • The need for good personal and oral hygiene should be discussed with the patient.

 

Nutrition

  • Protein is required for all the phases of wound healing, particularly important for collagen synthesis.
  • Glucose balance is essential for wound healing.
  • Iron is required to transport oxygen.
  • Minerals such as zinc and copper are important for enzyme systems and immune systems. Zinc deficiency contributes to disruption in granulation tissue formation.
  • Vitamins A, B complex, and C are responsible for supporting epithelialization and collagen formation. It is also important for the inflammatory phase of wound healing.
  • Carbohydrates and fats are essential. These provide the energy required for cell function. When the patient does not have enough, the body breaks down protein to meet the energy needs. Fatty acids are essential for wound healing.
  • Refer to a dietitian if the patient is malnourished.