Page 1343 - Equine Clinical Medicine, Surgery and Reproduction, 2nd Edition

1318 CHAPTER 13

VetBooks.ir The entry and exit points of the graft should be ade- BURNS
quately identified in order to facilitate identification
of the granulation tissue overlying the graft, usually
to barn or forest fires (Fig. 13.36). The most impor-
7–10 days after implantation, and allow its removal. Thermal injuries in horses are most frequently due
Failure to do so may lead to inadvertent graft dam- tant aspect when evaluating burns in the horse is to
age during the graft-uncovering process. provide analgesia and quickly evaluate the damage,
as a poor prognosis should be an indicator for eutha-
Split-thickness grafts nasia. The prognosis is directly related to the extent
Split-thickness grafts include mesh grafts, which are and severity of the burns. The amount of body sur-
technically demanding and unlikely to be practical face involved in a burn is expressed as a percentage
under field situations (Fig. 13.35). If a large area of total body surface area. Each forelimb represents
of skin needs to be grafted, it is best to refer these 9%, each hindlimb 18%, the head and the neck 9%
cases to a fully equipped hospital for application of a and the dorsal and ventral thorax/abdomen 18%
meshed sheet graft. each. Severe burns involving 50% of the body sur-
face area are associated with a high degree of mor-
Modified Meek technique tality. The severity of burns has been classified from
The modified Meek technique combines the use of a first to fourth degree (Table 13.5).
split-thickness and island graft and has been shown The systemic effects associated with burns depend
to have superior take (94%), greater expansion rates on the severity and extent of the burn and include
than mesh grafts and a significant improvement severe anaemia, haemoglobinaemia and haemoglo-
in wound contraction and epithelialisation. With binuria, hypernatraemia, immediate hyperkalaemia
this technique a larger area of skin can be grafted and a delayed diuretic hypokalaemia. Electrolyte
with the same size split-thickness graft. It requires monitoring during the first 2 weeks post wounding
a dermatome to collect a split-thickness graft is paramount to avoid serious electrolyte shifts and
(0.76–1.2 mm) and the subsequent use of a Meek ensure optimal systemic management. Horses with
micrograft machine to produce 196 island grafts of burns are at high risk of developing a life-threaten-
3 × 3 mm that are then placed in the previously pre- ing septicaemia, and systemic antibiotics are recom-
pared wound bed by means of a pre-folded gauze, mended. A high-calorie diet and possibly anabolic
with an expansion factor of 1:3. steroids are also required owing to the catabolic state

13.34 13.35

Fig. 13.34 Tunnel or ‘strip’ grafts are shown. Fig. 13.35 A split-thickness graft following
Note that the grafts are easily identifiable. This collection and meshing and ready to be applied.
will facilitate the location of the graft and prevent
iatrogenic damage during ‘de-roofing’.