Wound Management in Small Animal Practice

5 Things You Need To Know About Wound Management in Small Animal Practice

by Dr. Philip R Judge BVSc MVS PG Cert Vet Stud MACVSc (VECC; Medicine of Dogs)

Uncover 5 key tenets of effective wound management in dogs and cats that you can apply to ANY wound in your practice!

Give Your Wound a Name!

“If you can name it – you can tame it!” - Marc Brackett

Classifying a wound is all about creating a plant that will set you and your patient up for ultimate success in the management of the wound itself – AND avoiding the pitfalls associated with incorrect management!

The key concepts in classifying any wound include:

  • Is this wound clean?
    • Think: Sterile Surgery!
      • The most common type of clean wound is a surgical wound made with sterile instruments, in a non-contaminated environment, such as a surgical suite, following thorough surgical skin preparation. These are the wounds we can close with sutures – usually with minimal complication resulting.
    • Is this wound contaminated?
      • Think: Surgery gone wrong, or fresh, non-sterile wound!
        • Contaminated wounds are wounds that may look clean – but in fact, contain millions of bacteria and potential other microscopic debris within the wound itself. Examples of these wounds include those obtained from animals cut with sharp objects in their normal living environment, such as glass; or wounds obtained in a non-sterile manner within the veterinary clinic - including when sterile surgical fields become contaminated due to a break in aseptic technique. With careful management, many of these wounds may be able to have primary closure with sutures. However, if the wound is not managed appropriately, infection and delayed healing can be serious problems.
      • Is this wound dirty?
        • Dirty wounds are what they are – dirty.
          • These wounds often contain foreign material such as gravel, soil, hair and plant material. These wounds frequently have significant amounts of bacteria present, and may even have active infection present. These wounds usually benefit from management as an open wound – without suturing, to facilitate optimal healing.

Keys to Cleaning Your Wound

“To heal a wound, you need to stop touching it!”

Cleaning a wound might sound simple-  but there’s some pretty specific science behind the correct way to do it. As with any therapy in wound management, the goal of cleaning the wound is to facilitate wound-healing mechanisms by providing a warm, clean wound environment with a good blood supply. Read on to discover 3 key tenets of cleaning wounds! 

  1. Don’t make It Worse!
    1. First-aid care of wounds is vital to wound healing success. The most important rules to follow during first-aid care of wounds are to keep the wound moist, and to keep the wound as clean as possible. On arrival at the vet clinic, all wounds should be covered with saline-soaked sponges, and protected with a sterile, non-porous material such as a surgical glove, stapled over the wound dressing, until the wound can be treated. Wrapping wounds in sterile towels may be recommended - particularly for patients with multiple wounds covering large areas of the body surface. Application of a sterile, water-soluble lubricant onto the wound prior to covering reduces further wound contamination and wound drying.
  2. Dilution is the solution to pollution!
    1. Following patient stabilisation, the wound should be decontaminated. The initial process used to achieve this is called wound lavage. Would lavage is performed using large quantities of a sterile, isotonic, polyionic solution, such as lactated Ringer’s solution, and flushing the wound surfaces at a pressure of 8 PSI*. This process facilitates mechanical removal of gross wound contaminants, and dilution of wound contaminants. The benefit of wound lavage is largely determined by the volume of lavage solution – lavage of wounds with between 1 and 10 litres of saline (depending on wound size) is considered adequate.

* Optimum lavage pressure is 8 PSI. This can be achieved by using an 18 G needle attached to a 20-ml syringe.

  1. Debridement of the wound! Debridement is the removal of devitalized tissue from a wound to encourage rapid onset of wound healing. Removal of non-viable, or devitalized tissue reduces the amount of material white blood cells have to remove from the wound. Wound debridement can be achieved using debridement bandages, or surgical tissue resection – and may even need to occur multiple times, over several days to be complete.

All Wounds are Not created Equal – Selecting Wound Dressings

“Making better choices takes work” - Tom Rath

Selecting the right dressing for your wound is crucial! Select the wrong dressing, and the wound could end up a lot worse – with infection, delayed healing, or injury to deeper tissues and organs all possibilities.

How should we select a wound dressing? Careful evaluation of the wound colour, as well as the appearance and cytology of wound exudate can provide useful information that can guide dressing selection. The following table provides a quick reference to bandage selection based on the colour of the wound. Once selected, dressing choice can be modified based on the type and quantity of any exudate in the wound

Wound Colour

What’s Going On

Goals of the Dressing

What Dressing Should I Use?

Pink

Final stages of wound healing

Keep the wound moist and protected

Hydrogel ointment, with non-adherent contact foam

Red

Granulation tissue

Maintain a moist tissue bed, with sufficient absorption to control wound exudate

Hydrogel ointment with non-adherent film or foam

Yellow/White

Sloughing necrotic eschar

Surgical debridement, or rehydration and absorption

Hydrogels or hydrocolloids with non-adherent foam or alginate

Black

Dry wound with thick, hard eschar

Surgical removal of the eschar

Surgical removal preferred.

Green

Infection

Drainage of exudate away from wound surface

Manuka honey, silver, or sugar on wound surface, covered with absorbent foam dressing

Why Isn’t My Wound Healing?

“Just when you think it can’t get worse…”

Non-healing wounds are a problem, both for the patient, and for the veterinary team managing the wound. The important thing to know about non-healing wounds is that there is usually an underlying cause. Find the cause – effect a solution – and give the wound a chance to heal!

  1. Poor tissue perfusion.
    1. Poor tissue perfusion, electrolyte imbalances, and dehydration all lead to reduced oxygen and nutrient delivery to the site of the wound, and disordered cell function at the site of injury. Provision of intravenous fluid therapy to treat shock, restore hydration deficits, and to provide for maintenance fluids in critical patients is core to managing this problem
  2. Poor Nutrition
    1. Malnutrition, or inadequate food intake lead to the development of a catabolic metabolic state in the patient, which reduces the rate of wound healing, and leads to poor wound strength. Assisted feeding strategies are an essential component of improving wound healing.
  3. Infection!
    1. Wound healing cannot progress beyond the initial inflammatory phase if infection persists within the wound. Application of wound dressings aimed at reducing bacterial numbers (Manuka honey, for example), or performing surgical debridement of infected tissue is core to managing chronic wound infections and progressing the healing.
  4. Inappropriate Wound Dressings!
    1. Wound dressings play a key role in promoting wound healing. However, an incorrect dressing choice can delay, or even stop wound healing. Ensure your wound dressing is appropriate for the stage and type of wound you are managing is crucial to preventing these complications.

Common Mistakes in Wound Management

“Your best teacher is your last mistake”

The great things about mistakes is that they are avoidable. Here’s a few common mistakes to avoid in your next wound management case!

  1. Using tap water for wound lavage Sterile tap water has been used as a lavage solution, but has several characteristics that make is less than ideal as a lavage solution
    1. It is a hypotonic solution, that is alkaline, and that may contain toxic elements such as trace metals that impair wound healing
    2. Sterile tap water can damage cells within a wound in as little as 30 seconds
  2. Using topical antimicrobial agents in infected wounds.
    1. Whilst some antimicrobial ointments can be very effective against wound bacteria, many result in delays in wound healing if used beyond the granulation phase of wound healing, or enlargement of the wound.
  3. Using the same dressing for every wound!
    1. Wound types can vary from clean, to dirty, exudative to dry, from early inflammatory to late granulation phase. Using the same dressing for every type of wound will inevitably result in situations where a wound may fail to heal, or may deteriorate because of an inappropriate bandage. Carefully research available dressings and bandage materials appropriate for the wound you are treating, and success with wound healing us much for likely to occur.
  4. Starting antibiotics too early in burn wounds!
    1. Burn wounds are a special type of wound. The thermal injury actually sterilises the wound at the time of injury. Beginning antibiotic therapy early in burn wound management results in elimination of antibiotic-sensitive normal skin bacterial flora that may establish in the wound – leaving resistant bacterial to colonise the wound. Infections with these bacteria are generally much more challenging to treat as a result.

Disclaimer: Every effort has been made to ensure that the information contained in this article is current and correct. No responsibility is assumed by the publisher for loss or injury resulting from any use or operation of methods described herein. Because of rapid advances in medical sciences, independent verification of drug doses and recommendations should be made.