Page 621 - WSAVA2018
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dressing (e.g AllevynTM, Absorb PlusTM)
- For dry wounds which are at risk of desiccation, use dressings which restore moisture balance (DuodermTM, Instrasite GelTM, sterile saline soaked swabs)
Wound Healing
There are several stages of healing that occur sequentially over a period of time. The healing may occur at different rates in various areas of the same wound.
Stages of Healing
Divided into the following phases:
· Inflammatory
· Debridement
· Repair
· Maturation Inflammatory Phase
6-8 hours post wound occurring
· Immediate vasoconstriction and then vasodilation
· Clot is formed at the site of the injury to prevent further haemorrhage
· Plasma like fluid is produced to assist healing
· Erythema, heat, swelling and pain develop
Debridement Phase
6 hrs – 5 days post wound occurring
· Cellular activity is stimulated by the inflammatory process.
· This results in the production of exudates and discharge from the wound.
· The discharge has a cleansing effect as necrotic debris, white blood cells and tissue fluids are removed with the discharge
· Discharge = ‘pus’ which can be sterile or indicative of a bacterial infection.
· Performing cytology and looking at the discharge can determine proper wound care.
Repair Phase
Starting 3-5 days post wound occurring and lasting 3-12 days
· Blood vessels grow into the wound
· Granulation tissue forms to fill the wound area and epithelium begins to form along the edge of the wound
repair materials
· Collagen is laid down to give the wound strength
· The wound becomes smaller in diameter as the
granulation tissue starts to contract.
· Healthy granulation is red and shiny; it bleeds easily but is not painful.
Maturation Phase
· Begins 17-20days post wound occurring and can last up to 2 years
· This is when the collagen fibres in the connective tissue become replaced and realigned to give the area greater strength. The scar becomes pale and less obvious.
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Wound Strength
Factors in Wound Healing
Wound healing can be influenced not only by the type and depth of contamination (if present) but also the condition of the patient.
In order for healing to take place efficiently it is essential
· The area has a good blood supply. Functioning white blood cells, fibrinogen and numerous other substances need to get to the area. Debris and waste products need to be removed. Oxygen is need by all the cells to function well
· There is a good supply of the materials needed to conduct the repair.
Many factors that delay wound healing involves interference with the above two factors.
Wound factors that delay healing include:
· Poor blood supply – fails to carry healing cells, chemicals and oxygen to the areas as well as waste products and debris away from the area
· Dead space with accumulation of fluid – interferes with local blood supply
· Infection – negatively affects white blood cell function
· Foreign bodies or debris present – creates a persistent infection
· Oedema – interferes with blood supply. Patient factors that can delay healing include:
· Age (geriatric) – reduced circulation and immune function
· Systemic disease (diabetes, liver or renal dysfunction) reduced immune function
· Obesity – impaired circulation
· Malnutrition (low protein levels) – poor supply of
· Cancer and cancer treatments – reduced immune function
· Some medications – reduced immune function
· Self-trauma – impairs local blood supply.
Wound Healing Complications
Recognising wound complications can assist in appropriate treatment being implemented as soon as possible. Complications may include:
· Oedema
The area becomes puffy or spongy and pale in colour. It
may produce a watery fluid. When pressed gently with
   0-5 days
   Very little strength during the inflammatory and debridement stages
   5-21 days
  During the repair and maturation phase the wound strength starts to increase
   21+ days
  As the scar matures during the later maturation stage the strength will increase, but the final strength of the area is about 20% weak- er than the original tissue.

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