Wound Healing and Wound Management

Question 1

How does wound healing occur

Answer 1

Mediators are released to cause vasoconstriction to minimise blood loss.
Vessels then dilate and epithelial cells separate allowing plasma and cellular components to enter.
Activated platelets becomes blood clot which traps cells, clotting factors, and fibrin forming an extracellular matrix.
This serves as a binding site for neutrophils, macrophages and connective tissue cells.
Blood clot stabilise the edges of a small wound and dries to form a scab.
Scab will eventually slough off.
Larger wounds does not form a scab.

Question 2

Stages of wound healing

Answer 2

1) Inflammation and debridement phase
2) Repair and proliferation stage
3) Maturation phase

Question 3

Inflammation and debridement phase

Answer 3

• Arrival and activity of neutrophils and monocytes
• Neutrophils phagocytize bacteria and extracellular debris
• removes them by means of exudate (pus)
• Pus made up of: degrading neutrophils, wound fluid, and denatured tissue
• Exudate: can be serosanguinous to purulent in nature
• Monocytes: become wound macrophages with phagocytic properties, modulate growth factors - critical for ongoing wound healing

Question 4

Repair or proliferation phase

Answer 4

• Proliferative processes:
  1) angiogenesis
• growth of new capillaries from existing vessels at wound edges and areas within the wound bed
• makes granulation tissue look a rich deep red colour that pales over time
• 3-5 days old to show granulation tissue
  2) Fibroplasia
• influx of fibroblasts into the wound
• replaces initial fibrin to a more permanent collagen
• establish extracellular matrix
• accumulated collagen organized into connective tissue around 7-14 days
• contraction = reduction in wound size
• epithelialization countinues to cover the wound
  3) Maturation phase
• Remodelling of connective tissue
• increase in strength of the wound
• only 70% strength of normal tissue
• Wound contraction also occurs here

Question 5

Under what situations would you not try and stabilise a patient before addressing their wounds?

Answer 5

Arterial bleeding, open thorax wound, eviscerated organs

Question 6

How is a wound usually cleansed?

Answer 6

Normal saline

• Volume of flush is more critical than the pressure which it is delivered.
• Pressures above what is encountered using a 60ml syringe with an 18 gauge needle can be deleterious due to high pressure driving debris into the tissues instead of washing them away
• Sterile technique
• Chlorhexidine 0.05%
• DO NOT USE alcohol or hydrogen peroxide

Question 7

Primary closure

Answer 7

Complete and immediate closure of a wound or surgical incision

• wound will be managed as an open wound initially to allow drainage
• debridement usually required
• drain placement usually required

Question 8

Secondary closure

Answer 8

Performed on a wound that has been managed as an open wound for at least 5 days

• wound should have a healthy bed of granulation tissue present
• drain placed
• wound trimmed an place into direct apposition

Question 9

Second intention healing

Answer 9

Managing a wound as an open wound where healing occurs through epithelialization, granulation and contraction only

• some large defects will not heal completely
• scar will be significant
• may be the only choice for some wounds