Traumatic wounds are a common presentation seen by first opinion and emergency practices. Appropriate initial acute wound management is key to promoting the healing process and augmenting the chances of a positive outcome for the patient.
Regardless of wound aetiology, all traumatic wounds present with similar features that impair or stop wound healing, such as bacterial contamination, foreign material contamination and necrotic tissue. This article will outline how to manage an acute traumatic wound on presentation step by step.
Initial assessment and stabilisation of the patient is the first priority. This is because the trauma that led to the occurrence of a wound may have damaged other structures, compromising the survival of the patient. On its own, a wound will rarely lead to the death of a patient.
Initial assessment and stabilisation of the patient is the first priority […] because the trauma that led to the occurrence of a wound may have damaged other structures
While stabilisation is performed, a basic wound cover to keep a moist environment and prevent further wound contamination is necessary until further wound management is possible. This is particularly important since most patients will not tolerate wound assessment and management consciously, therefore the cardiovascular system must be stabilised before any sedative or general anaesthetic drugs can be administered.
Wound protection and skin preparation
Sterile lubricant gel should be applied to prevent fur and debris from contaminating the wound while clipping is performed. Wide surgical clipping should be done around wound edges to allow subsequent surgical intervention with appropriate aseptic skin preparation. The clippers should have clean, sharp blades to avoid any additional skin damage caused by the clipping.
The intact skin surrounding the wound should be surgically scrubbed and aseptically prepared without contamination of the wound. Different practices have different protocols, but chlorhexidine at a 2 percent dilution is appropriate for skin scrubbing and is therefore commonly used. Chlorhexidine is an effective antiseptic scrub but can be harmful to exposed wound beds. Scrubbing must start close to the wound edges and the scrub technician should continue to work towards the skin further from the wound to prevent wound contamination (similarly to how surgical sites are prepared).
The objective of wound lavage is to decrease the microbial burden and remove any gross debris not embedded in the wound. Therefore, consideration of how the lavage is performed is more important than the solution used.
Sterile water, household tap water, saline and other commercial solutions have shown similar results when used to flush wounds (Weiss et al., 2013). However, some authors do not recommend non-buffered solutions (and prefer Hartmann’s or Ringer’s lactate solution) as, experimentally, these can cause injury to canine fibroblasts whereas buffered solutions do not. While specific fluid choice may remain controversial, the efficacy of wound lavage is improved with early implementation using copious volumes.
While specific fluid choice may remain controversial, the efficacy of wound lavage is improved with early implementation using copious volumes
An example of a system that has been shown to be effective, inexpensive and easy to use requires the following:
- 1l bag of isotonic solution
- Pressure bag
- Fluid giving set
- 19 gauge needle
The bag of lavage solution is placed in the pressure bag. The giving set is then connected to the bag and a 19G needle is placed on the other end of the giving set. The pressure bag is inflated until a pressure of 300 to 400mmHg is achieved. This set-up should dispense the flush solution at a pressure strong enough to allow debris removal and dilution of the bacterial burden present without causing damage to the tissues.
Some authors prefer to use a 20ml syringe attached to a three-way tap and a 19G needle instead of using the pressure bag. This also provides adequate pressure; however, it takes more time since the operator needs to keep emptying and filling the syringe.
The objective of debridement is to remove any non-viable tissue, whether necrotic, damaged or ischaemic, from the wound. Non-viable tissue will delay wound healing, promote bacterial growth and impair re-epithelialisation and wound contraction.
Surgical debridement is the quickest and most effective method of debridement. This can be done en bloc or in layers. As per any surgical procedure, Halsted’s surgical principles should be followed which involve:
- Following a surgical aseptic technique to prevent further wound contamination
- Handling the tissue gently with sharp instruments and thumb forceps (this is key). A scalpel blade is better to debride since it does not crush the tissues as scissors do
- Taking care to preserve the blood supply and maintain haemostasis otherwise the tissue becomes non-viable and will require debridement
Tissue apposition, ensuring the wound is tension-free and obliterating dead space are the three final points. Although they are more relevant to decision making post-debridement, they are also crucial points to consider.
Surgical debridement is not always entirely effective when the wound is embedded with foreign material or when there is no availability to take the patient to surgery
However, surgical debridement is not always entirely effective when the wound is embedded with foreign material or when there is no availability to take the patient to surgery. In those cases, mechanical debridement may be used.
Mechanical debridement relies on friction, or adherence, to lift necrotic tissue from the wound bed. This is commonly achieved by placing a wet-to-dry bandage.
Prior to the application of a wet-to-dry dressing, the steps outlined above should be performed (wound protection, skin preparation, wound lavage and surgical debridement when possible). Again, an aseptic technique should be followed.
A gauze swab moistened with saline is placed in direct contact with the exposed wound without making contact with the intact skin but ensuring the swab is in contact with all the wound pockets and corners. The following layers of the bandage will be dry swabs to help absorb moisture from the damp ones. A secondary layer of highly absorbent dressing material (cotton roll for example) is placed under compression to allow further wound moisture absorbency. The tertiary layer is composed of porous bandage material that helps compress the secondary layer and allows evaporation.
Wet-to-dry dressings should not be left in place for longer than 24 hours, and removal may have to be sooner if strike-through is noted. Adherence between the primary layer and the wound bed will lead to mechanical debridement of necrotic tissue and debris.
A further debridement type that is commonly used is autolytic debridement – a process in which debridement occurs naturally as part of the body’s healing capability.
[Autolytic debridement] can be optimised if the wound bed is kept moist
The patient produces enzymes and activates phagocytes that play a role in the autolytic debridement of the wound. This process can be optimised if the wound bed is kept moist (with appropriate dressings), the patient has adequate nutritional support and the steps described above regarding acute wound management are followed.
What’s next in acute wound management?
Once the debridement phase is over or the debridement is deemed satisfactory, appropriate wound closure can be planned. Immediate or delayed primary closure may be performed. Where debridement has taken longer and granulation tissue has formed, secondary closure may be considered.
The clinician may decide against surgical closure and instead opt for open wound management to promote healing via secondary intention. Making this decision will depend on wound progression, location, veterinary surgeon or nurse preference, and owner commitment. However, independent of the final decision, the initial acute wound management outlined above is imperative to optimise the chances of a positive outcome.