CLINICAL - Wounds Flashcards
What are the four phases of wound healing?
Inflammatory phase
Debridement phase
Proliferation phase
Remodelling phase
Which markers can be increased during the inflammatory phase of wound healing in horses?
Matrix metalloproteinases 2 and 9
Neutrophil elastase
What phase of healing is this equine wound in?
Debridement phase (phagocytic cells begin breaking down tissue)
What phase of healing is this equine wound in?
Proliferation phase
What phase of healing is this equine wound in?
Remodelling phase
List six local factors which can negatively influence wound healing
Poor perfusion
Infection
Movement
Foreign material
Fluid accumulation (seromas)
Tissue deficit
List five systemic factors which can negatively influence wound healing
Age
Neoplasia
Metabolic disease
Drugs
Nutrition
How can movement disrupt wound healing?
Movement disrupts granulation tissue and epithelialisation and increases tension at the wound margins
What can you do to reduce movement that would disrupt wound healing in horses?
Splints/casts
How does the presence of foreign material disrupt wound healing?
Foreign material is a focus for infection and prolongs the inflammatory response
What can you do to check for the presence of foreign bodies in wounds?
Radiography
Which five factors promote optimal wound healing?
Good perfusion
Moist wound surface
No surface trauma to the wound
Controlled infection
Non-viable and foreign material removed from the wound
What are the four classifications of wounds based on contamination?
Clean
Clean contaminated
Contaminated
Dirty
What are the seven Halstead’s principles that should be followed when surgically closing wounds?
- Gentle tissue handling
- Maintain normal homeostasis
- Maintain local blood supply
- Use aseptic technique
- Close tissues without tension
- Careful approximation of tissues
- Ensure no dead space
What are the four options for wound closure?
Primary closure
Delayed primary closure
Secondary closure
Healing by second intention
What is primary wound closure?
Primary wound closure is the immediate mechanical closure of healthy, viable, clean tissue that is not under tension
Which suture material is best for primary wound closure?
Monofilament nylon
Monofilament polypropylene
What is delayed primary wound closure?
Delayed primary wound closure is the delayed mechanical closure of the wound until just before granulation tissue formation to allow for open wound management
List four factors that will result in delayed primary and secondary wound closure
Wound contamination
Necrotic tissue
Swelling
Infection
What is secondary wound closure?
Secondary wound closure is the delayed mechanical closure to allow for open wound management and granulation tissue formation
Which classification of wounds should be closed using secondary closure?
Contaminated wounds
What is healing by second intention?
Healing by second intention allows the wound to heal itself following open wound management
Which classifications of wounds should be closed using healing by second intention?
Dirty wounds
Wounds with large skin deficits that cannot be mechanically closed
What is open wound management?
Open wound management is a method that allows you to prepare a wound for delayed closure or for healing by second intention through identifying and controlling infection, debriding necrotic tissue and preventing further contamination and wound damage
(T/F) Open wound management can be carried out in awake patients
FALSE. Open wound management should be carried out under heavy sedation/general anaesthetic
What are the four stages of open wound management?
- Carry out a wide clip around the wound
- Wound lavage
- Wound debridement
- Wound dressing
What is the purpose of wound lavage?
Wound lavage reduces bacterial contaimination, removes foreign material and rehydrates necrotic tissue to allow for easier debridement
What kind of fluid should you use for wound lavage?
Sterile saline or Hartmann’s solution
How do you set up for wound lavage?
Attach an appropriate bag of sterile fluid to a giving set. Attach the giving set to a three way tap attached to a 20 - 30ml syringe and 19 gauge needle
Which lavage technique is particularly useful in horses?
Hydrosurgical lavage
Why should you never put chlorhexidine or iodine into a wound?
Although chlorhexidine and iodine are useful for disinfecting intact skin, they have a negative effect on wound healing and tissue regeneration as they can cause cell death
Why should you not put local anaesthetics directly into wounds?
Local anaesthetics should not be out directly into wounds as local anaesthetics impede the migration of leukocytes
What are the two classifications of wound debridement?
Surgical debridement
Non-surgical debridement
What is surgical debridement?
Surgical debridement involves the sharp dissection of necrotic tissue with a scalpel
What is non-surgical debridement?
Non-surgical debridement is the non-selective ‘stripping’ of necrotic tissue using adhesive dressings
Descirbe how non-surgical debridement is carried out using wet to dry dressings
A sterile open weave swap is soaked using sterile saline or Hartmann’s solution and applied to the wound and covered with a dry sterile open weave swab. As the wet swab dries, it adheres to the wound and when removed it ‘strips’ the tissue
What are the disadvantages of non-surgical debridement?
Non-selective so can cause damage to healthy tissue
Very painful so has to be done under general anaesthetic
How can necrosis disrupt wound healing?
Necrosis is a focus for infection and prolongs the inflammatory response
What is the purpose of wound dressings?
Wound dressings protect the wound and encourage granulation tissue formation and epithelialisation
What are the three layers of a wound dressing?
Contact layer
Secondary layer
Tertiary layer
What is the purpose of the contact layer?
The contact layer controls the wound environment to encourage granulation tissue formation and epithelialisation
What are two classifications of contact layers?
Adhesive contact layer
Non-advesive contact layer
Give an example of an adhesive contact layer
Wet to dry dressing
When are adhesive contact layers used?
Adhesive contact layers should only be used in the very early stages of wound management for non-surgical debridement
How often should you change adhesive dressings?
You should change adhesive dressings a minimum of every 24 hours
Give two examples of non-adhesive contact layers
Foam dressings
Hydrogels
What is one of the main benefits of foam dressings?
Foam dressings have a semi-permeable membrane which allows for oxygen exchange and controlled evaporation to keep the wound moist but not wet
What are some of the main benefits of hydrogels?
- Maintain moisture
- Fit into irregular wounds
- Encourage natural debridement
- Can be used in combination with foam dressings
- Almost painless to remove so are good for patients where repeated anaesthetics are unfeasible
What is the main disadvantage of hydrogels?
Hydrogels are very expensive
What is the purpose of the secondary layer?
The secondary layer holds the contact layer in place and absorbs any exudate that is drawn from the wound
Which three materials are commonly used for the secondary layer?
Cotton wool
Soffban
Conforming gauze bandage
What is the purpose of the tertiary layer?
The tertiary layer protects the other layers from trauma and contamination and holds the bandage in place
Which material is commonly used for the tertiary layer?
VetWrap
When are antibiotics indicated when treating wounds?
Antibiotic treatment is indicated in almost all traumatic wounds
Give two examples of topical treatments that can be beneficial when treating wounds
Silver dressings
Manuka honey
What are the therapeutic benefits of silver dressings in treating wounds?
Antiseptic
Antibacterial
What are the therapeutic benefits of Manuka honey in treating wounds?
Anti-inflammatory
Antibacterial
Naturally debrides wounds and draws out exudate due to its osmotic effect
Promotes rapid granulation tissue formation
When should you stop using manuka honey on wounds?
You should stop using manuka honey on wounds when granulation tissue begins to form as manuka honey can actually cause dessication of granulation tissue
What should normal granulation tissue look like?
Red
Uniform and flat
Minimal exudate
What is ‘proud flesh’?
‘Proud flesh’ is excessive granulation tissue which protrudes from the wound
Why is ‘proud flesh’ such a common complication in horse skin wound healing?
‘Proud flesh’ is very common in horse skin wounds as horses have a continuous low level inflammatory response and prolonged fibroblast proliferation, all of which contribute to excessive granulation tissue formation
List six factors which encourage ‘proud flesh’ development in horses
Excessive moisture
Excessive warmth
Movement
Infection
Low pH levels
Low oxygen levels
What is the best way to manage ‘proud flesh’ in horses?
Surgical excision of the ‘proud flesh’ followed by treating the underlying cause that is encouraging the ‘proud flesh’
i.e. if the proud flesh is over a joint, this is most likely due to movement so it can be useful to put the horse in a cast/splint to immobilise the joint
Which six steps should you take during every wound dressing change?
- Fully assess the patient
- Lavage the wound
- Wound debridement as necessary
- Photograph the wound and make detailed clinical notes on progression and treatment plan
- Re-dress the wound if necessary
- Update the owner on wound progression and prognosis
How does wound healing differ in cats compared to dogs?
Cats have a slower rate of cutaneous wound healing as well as reduced granulation tissue formation and epithelialisation
Why do wounds in ponies heal quicker and more efficiently than they do in horses?
Horses have slower and less effective epithelialisation, fibroblast growth, and wound contraction compared to ponies. This is due to the weaker initial inflammatory response seen in horses
When does granulation tissue begin to form during wound healing in horses?
Granulation tissue begins to form 4 days into wound healing in horses
When does epithelialisation begin during wound healing in horses?
Epithelialisation begins 10 -14 days into wound healing
How much epithelialisation occurs per day during wound healing in horses?
There will be 1.2mm of epithelialisation per day during wound healing in horses
How long does it take for a 10cm wound to heal and close by second intention in horses?
It takes 3 months for a 10cm wound to heal and close by second intention in horses
How often should you change a dressing in horses?
You should change dressings every 4 - 5 days in horses
Can skin wounds case lameness in horses?
No, skin wounds don’t tend to cause lameness in horses. If you see lameness in a horse this suggests that there is damage to an underlying structure
What is contracture?
Contracture is the shortening and hardening of tissues resulting in the prevention of normal movement
Wounds to which three regions of the horse can cause contracture if not managed properly?
Ears
Nostrils
Tail base
(T/F) You should always remove tissue flaps in equine wounds
FALSE. Never remove tissue flaps unless you are certain the tissue is necrotic/devitalised
Why should you always retake radiographs of open fractures in horses later into the healing process?
To investigate for the presence of sequestra
What should you always check when presented with an equine wound?
When presented with an equine wound, always check the horse’s tetanus status, if the horse is not vaccinated give the horse tetanus antitoxin immediately
