Intro to Wound Management

Question 1

What should assessment of wounds include?

Answer 1

• Wound factors (i.e. classification).
• Patient factors (comorbidities, medications etc).
• Length of time since injury occurred (acute vs chronic).

Question 2

Give the 2 main aspects of wound classification.

Answer 2

• Type of damage.
• By extent of contamination.

Question 3

1. Give examples of types of damage.
2. Give examples of extents of contamination.

Answer 3

1. Abrasion (graze), contusion (bruising), incision (cut – could be surgical), laceration (irregular complex tissue damage), puncture, degloving, burn.
2. Clean e.g. surgical incision, clean-contaminated e.g. surgery involving entry to GI / urinary / respiratory tract, contaminated e.g. fresh traumatic wound, infected/dirty e.g. older wounds where contamination not controlled.

Question 4

1. What are the 4 phases of wound healing in order?
2. What does granulation tissue look like? – why?

Answer 4

1. Haemostasis > inflammation > proliferation > remodelling.
2. Bright red – highly vascular.

Question 5

1. Why is it important to identify what phase of healing a wound is in?

Answer 5

1. So you can identify that the wound is progressing through healing appropriately.
   So appropriate management is carried out for the phase of healing e.g. topical meds / choice of dressings.

Question 6

Problems in wound healing.

Answer 6

Tissue loss i.e. not enough tissue to achieve tension-free apposition).
– Due to the wound itself or the debridement that was necessary in treatment of the wound.
– May make primary closure difficult / impossible.

Infection
– Due to heavy initial contamination or delayed treatment.
– Or due to initial foreign material or necrotic tissue

Inability to contract
– Location dept.

Movement where wound keeps pulling apart.
– Dehiscence if primary closure attempted.
– Can cause excessive granulation tissue.

Compromise of blood supply
– Reduced ability to deal with infection.
– Dead tissue.

Question 7

What other structures could be affected that are not being seen beyond the wound, thus making anatomical knowledge very important.

Answer 7

Synovial cavities – joints, tendon sheaths, bursae.
Bone, tendons, ligaments.
Major blood vessels and nerves.
Chest or abdomen and the viscera within.

Question 8

What are the steps of wounds management?

Answer 8

1. Assess whole animal and stabilise.
2. Assess wound and explore.
3. Debride wound.
4. Lavage.
5. Culture and systemic medications.
6. Decision making – Should you close the wound?
7. Drains.
8. Topical medications.
9. Dressings and bandages.

Question 9

Aspects of assessing the whole animal and stabilising them.

Answer 9

Make animal and people safe e.g. muzzle and sedation (+/-).
Identify life threatening problems at triage.
Prevent further contamination – wear gloves!
Pain relief e.g. opioid.
Further diagnostics if concerned wound has penetrated body cavity e.g. radiographs, ultrasound, centesis etc.
Any emergency stabilisations.

Question 10

Aspects of assessment and exploration of the wound.

Answer 10

Any deep or penetrating wound explored under GA.
Clip and clean
- Protect wound by packing with moist sterile gauze +/or fill wound with jelly/intrasite.
- Extensive clip and heck for other wounds.
- Initial clean with saline or dilute hibi (povidone iodine not active if organic debris).

Classify severity
- Type of damage and depth.
- Sterile probe into punctures and extend any pockets – follow wound to deepest extent and check for FB/contamination e.g. hair.
- Damage to underlying structures? (concerns for horse joints).
- Is wound damaged or infected already?

Question 11

Aspects of debriding the wound.

Answer 11

Remove dead tissue (green/grey/black) and major contamination. Purple tissue might survive.
Debridement can be achieved:
- Surgical excision.
- Lavage.
- Dressings.
– Wet to dry dressings (sterile swab soaked in sterile saline, packed into wound and changed after 24hrs).

Question 12

Aspects of lavage.

Answer 12

Copious lavage is key! - DILUTION IS THE SOLUTION TO POLLUTION.
Use:
- Sterile saline or Hartmann’s.
- Severe contamination – can use water (esp LA) then move on to saline. Too much water can cause oedema as hypotonic.
- Care with antiseptics – can be toxic to fibroblasts.

Correct pressure controversial – too high can push contamination into the tissues.
Ideal = 1 litre fluids, 16G needle and a pressure bag at 300mmHg.

Question 13

Aspects of culture and systemic medications.

Answer 13

Take a swab AFTER lavage and debridement to avoid the contaminants.
Antibiotic therapy?
- Yes if bite wound or heavily contaminated.
- Broad spectrum initially (e.g. amoxy-clav, cephalosporins, cefovecin).
- If significant wound, consider IV antibiotics.
Analgesia
Tetanus antitoxin in horses if unknown vaccination status.

Question 14

Wound closure options?

Answer 14

Primary closure
Delayed primary closure
Secondary closure
Second intention healing

Question 15

What is primary closure?

Answer 15

Immediate closure of the wound with sutures/staples.
For fresh (<6hrs) wounds that are or can be rendered clean before closure.
Best functional and cosmetic outcome where deployed correctly.
May dehisce if ongoing infection or tissue necrosis.
Can still close >6hrs but debridement will be needed. Earlier is better.

Question 16

What is delayed primary closure?

Answer 16

Where wound is closed at 2-3 days old and before granulation tissue develops – use for contaminated wounds after initial wound management.

Question 17

What is secondary closure?

Answer 17

Where wound is closed at 5-7 days old and after granulation tissue has developed.
Use for heavily contaminated / infected wounds after initial open wound management.
May need to excise granulation tissue to allow closure.

Question 18

What is second intention healing?

Answer 18

Relied on if the wound cannot be surgically closed. Heals entirely by granulation, contraction and re-epithelialisation.

Question 19

1. Consequence of tension on closure?
2. How can tension be alleviated?

Answer 19

1. Increased risk of dehiscence.
2. Skin tension lines.
   Undermining.
   Walking sutures.
   Relaxing incisions.
   ‘Manipulation of wound geometry’.

Question 20

More advanced tension-relieving techniques.

Answer 20

Advancement flaps.
Skin stretching / expansion.
Skin grafts (usually autografts i.e. from same animal).
– Pedicle grafts - retain a vascular attachment with either random pattern (blood from general subdermal plexus) or axial pattern (blood from specific cutaneous artery/vein).
– Free skin grafts with either sheets or island grafts (pinch/punch/tunnel grafts).

Question 21

What could be used if there is a large amount of dead space?

Answer 21

Put a drain in.

Question 22

1. Topical antibiotics and antiseptic that can be used on wounds. – considerations.
2. Hydrogels that can be used on wounds – why?
3. Honey / sugar pastes that can be used on wounds. – why? when?

Answer 22

1. Dilute chlorhexidine, silver sulfadiazine.
   Not commonly used, depends on specific circumstances. – can be damaging for fibroblasts involved in healing.
2. Intrasite – moist wounds heal more quickly so used in many open wounds to encourage healing environment.
3. Manuka honey e.g. Activon. – Reduces swelling and combats infection (antibacterial). Used mostly in early stages with contaminated wounds.

Question 23

Functions of a bandage.

Answer 23

Maintain dressing in place over wound.
Help with absorption of exudate.
Help to control swelling.
Reduces movement.
Prevent contamination from the environment.

Question 24

3 layers of bandage.
Hoe can the bandage be further protected?

Answer 24

Primary layer = dressing against the wound itself.

Secondary layers = absorbent, holds dressing in place, light pressure to provide structure to the bandage. may include a padding layer and a conforming layer.

Tertiary layer = outer layer – keeps everything together and protects bandage from the animal, environment and trauma.

Keep bandage dry by temporarily covering with a drip bag when animal goes outside.

Question 25

Key properties of the primary layer.

Answer 25

Adherent vs non-adherent – adherent will further debride wound upon removal (e.g. wet to dry). Saline swabs and saline make cheap adherent dressings. Once wound clean and healthy, non-adherent dressing will avoid damaging repair tissue. Non-adherent may include foams e.g. Allevyn.

Absorbent vs non-absorbent – Absorbent dressings helpful where there is significant wound discharge.

Question 26

What can be done to cover an open-wound in a location that is difficult to bandage?

Answer 26

Tie-over dressing. Loops of suture placed into the skin around the wound under GA and a dressing can be tied over the top and changed regularly.

Question 27

What can go wrong with horse wounds?

Answer 27

Synovial penetration.
Exposed bone.
Exuberant granulation tissue.
Hoof involvement.
Sarcoids.

Question 28

1. What can occur if a horse’s joint is penetrated?
2. What is the important aim of wound exploration in horses?

Answer 28

1. Septic arthritis leading to NWB lameness.
2. Identifying if there is a joint/sheath/bursa involvement.

Question 29

How do you check for synovial involvement when exploring a wound?

Answer 29

Insert needle into joint/sheath (away from the wound not through the wound).
Distend joint markedly with sterile saline.
Check for egress at the wound itself.
Can catch any free fluid and send off for a cytology sample.

Question 30

1. What type of injury causes exposed bone?
2. And in what anatomical location?
3. Risk with exposed bone?
4. What actions must be taken to minimise the risk?

Answer 30

1. Degloving.
2. Where little tissue between skin and bone e.g. distal limbs.
3. Exposed cortical bone will dry out and then is at increased risk of becoming sequestered.
4. Cover with bandaging until granulation tissue covers it.

Question 31

1. How can a hoof be stabilised if found to be involved in wound?

Answer 31

1. Bar shoe and suture/wire to ensure future growth of hoof does not lead to significant defect.
   (Disruption of coronary band will create a long standing hoof defect).

Question 32

1. Lay term for exuberant granulation tissue?
2. Commonly occurs where?
3. Cause?
4. Management aim?
5. What cell type will persist in the wound environment?
   – What do these cells inhibit?

Answer 32

1. Proud flesh.
2. Distal limbs of horses.
3. Slow and ineffective inflammatory response associated with movement or contamination at wound site, or BANDAGING!
4. Remove/inhibit granulation tissue but not new epithelium by surgical debridement / systemic or topical medications.
5. Macrophages.
   – Inhibit the differentiation of fibroblasts to myofibroblasts.

Question 33

Factors affecting wound healing in horses.

Answer 33

Physical status of the wound e.g. tension.
Blood supply to the area.
Location.
Nutrition – vitamins A, C, E and Zinc.
Trauma e.g. contusion – prolongs inflammation.
Movement.
Bandages/dressings.
FBs.
PPID (pituitary pars intermedia dysfunction) – Cushing’s.
Sarcoid development.
Infection prolongs inflammatory and debridement phases, exudate separates wound edges, bacterial enzymes degrade new collagen.
NSAID use can prevent chronic inflammation.
Corticosteroids retard healing but slow EGT.

Question 34

How does infection affect wound healing?

Answer 34

Prolongs inflammatory and debridement phases.
Exudate separates wound edges.
Bacterial enzymes degrade new collagen.

Question 35

1. What is a sarcoid?
2. How is it spread?
3. How is spread of these prevented?
4. What should be done when ANY excessive granulation tissue?

Answer 35

1. Fibrosarcoma tumour caused by bovine papilloma virus and prone to form at wound sites (incl. injection sites).
2. By flies and humans.
3. Keep wounds covered.
   Apply plenty of fly repellent on existing sarcoids and AROUND open wounds.
4. Pop in formalin for future biopsy as potential reason for non-healing proliferative wounds.