Today's Veterinary Practice provides comprehensive information to keep every small animal practitioner up to date on companion animal medicine and surgery as well as practice building and management.
| TODAY'S TECHNICIAN Anatomy Review
The skin and its associated tissues are comprised of the epidermis, dermis, and hypodermis (subcutaneous tissue). Their job is to pro- tect the underlying muscle, bone, ligaments, and internal organs.
Epidermis Dermis
Hypodermis/ Subcutaneous Tissue
Outer layer of the skin; provides a barrier against water and infection
Layer under the epidermis; contains collagen, elastic tissue, and reticular fibers that provide strength and elasticity
Layer under the dermis; attaches skin to the muscle layer. It mostly consists of connective and adipose tis- sue that provides insulation and protection for the body.
UÊPuncture: Penetrating wound caused by a sharp object; punctures cause minimal skin damage but underlying tissue damage may be severe, resulting in a higher risk of subsequent infection by contamination introduced at time of puncture1
Closed Wounds UÊ onÌÕÃion\ Blunt-force trauma that doesn't break the skin but causes damage to the skin and underlying tissue
UÊ ÀÕÃhin}Ê njÕÀÞ: Force applied to an area of the body over a period of time; commonly seen in bite wounds
Duration & Degree of Contamination Duration refers to the length of time between the infliction of a wound and wound treatment. Duration and degree of contamination are divided into 3 classes.1
However,
the degree of contamination is more important than the duration; a relatively new wound that has gross debris or devitalized tissue should be assigned a higher wound clas- sification. UÊ l>ÃÃÊ £\ Clean wound with minimal contamination and a 0 to 6 H duration
UÊ l>ÃÃÊÓ\ Wound with significant contamination or 6 to 12 H duration
UÊ l>ÃÃÊÎ\ Wound with gross contamination or > 12 H duration
WOUND HEALING Phases of Wound Healing There are 3 phases of wound healing; healing can take place on its own or with medical or surgical intervention. *h>ÃiÊ £ÊpÊ nvl>mm>ÌoÀÞÊ *h>Ãi\ This phase occurs
immediately after injury and is mainly directed at minimiz- ing blood loss from the injured area by hemostasis—vaso- constriction, platelet aggregation, and clot formation—fol- lowed by vasodilation and phagocytosis. *h>ÃiÊ ÓÊpÊ*ÀoliviÀ>ÌiÛiÊ*h>Ãi\ In this phase, granu-
lation, contraction, and epithelialization of the injured tissues occurs. *h>ÃiÊÎÊpÊ,imo`ilin}Ê*h>Ãi\ This phase involves for-
mation of new collagen, wound tissue strengthening, and scar formation.
62 Today's Veterinary Practice January/February 2012
Figure 1. Bite wound of the metatarsal area that was infected and is now closing by second intention.
Initial Treatment The initial treatment of a wound should include: £°Ê li««in}Ê ÀoÕn`ÊÌhiÊ7oÕn`\ A water-soluble gel (ie, K-Y Jelly, jnj.com) is placed in the wound and a large area of skin around the wound is clipped. The gel clumps the clipped hair together and prevents further wound contamination during clipping.
Methods of Wound Healing UÊ iÀÃÌÊ nÌinÌion\ÊDescribes primary wound healing or closure; this type of healing is the best choice for healthy wounds in well-vascularized areas. UÊ -iVon`Ê nÌinÌion\ Describes sec- ondary wound healing or spontane- ous healing. In this process the open wound is allowed to close by epitheli- alization and contraction (granulation tissue); this process of healing is best for contaminated or infected wounds ( i}ÕÀiÊ£). UÊ-iVon`>ÀÞÊ loÃÕÀi\ Wound closure > 5 days after injury; granulation tis-
sue and epithelialized skin edges are excised and fresh tissue edges closed.
UÊ/hiÀ`Ê nÌinÌion\ Describes tertiary wound healing or delayed primary closure; it is best for infected or unhealthy wounds that are too contaminated for primary closure, but appear clean and well vascular- ized after approximately 2 to 5 days.
UÊ «iÌhili>liâ>Ìion\ Describes healing of partial-thick- ness wounds, including first-degree burns and abrasions.
TREATMENT OF WOUNDS How a wound is treated initially and the bandaging technique employed will greatly impact the outcome of a patient's injury. Poor treatment and bandaging techniques will delay healing, negatively affect patient outcome, and accrue unnecessary charges for the client.