Emergency Wound Management and Vacuum-Assisted Wound Closure

Jason Wheeler, Charlottesville, Virginia

A variety of wounds are seen during emergency practice. Many wounds in small animal practice are traumatic in origin, such as lacerations, bite wounds, open fractures, degloving injuries, and those resulting from automobile accidents and penetrating/projectile objects. Additionally, envenomations, burns, and surgical dehiscence are commonly encountered. The mechanism of injury, the time from injury, and the level of wound contamination are all crucial management factors. Patient characteristics including age, obesity, nutritional status, serum albumin, and concurrent diseases such as hyperadrenocorticism, diabetes mellitus, and neoplasia also affect wound healing.

The so-called golden period is the time from injury to development of infection with 10⁵ organisms/gram of tissue. This time period, which on average lasts 6 hours, provides the best opportunities for wound management and closure.

Wound healing begins immediately after injury and occurs in four phases. The first phase, the inflammatory phase, lasts up to 5 days and begins with hemostasis and the release of cytokines and inflammatory mediators to initiate migration of neutrophils toward the wound. The second phase is débridement of the wound by neutrophils and monocytes that mature to macrophages. Macrophages and neutrophils clean the wound bed of debris, bacteria, foreign material, and necrotic tissue. Débridement lasts for 3 to 5 days and sets up the wound bed for repair. The repair phase usually begins 3 to 5 days after the initial injury and lasts up to several weeks. During the repair phase angiogenesis, fibroplasia, and collagen synthesis set up the meshwork for epithelialization of the wound. The final phase, maturation of the wound, may last for years as connective tissue and collagen fibers remodel to increase wound strength.

Initial Assessment and Treatment

Severe wounds are commonly seen in association with multiple traumatic injuries. The wounds are often impressive and can distract the clinician from more life-threatening concurrent injuries. While the patient’s life-threatening injuries are addressed, the wound should be covered or bandaged for basic stabilization and to prevent further contamination by nosocomial organisms. The wound can be evaluated, cleaned, and definitively managed at a later time.

Initial Patient Management

The patient’s cardiovascular status should be fully stabilized with fluid therapy (see Chapters 1 and 2) and analgesic drugs such as pure mu opioid agonists administered (see Chapter 12) prior to addressing the wound. The wound should be covered with a sterile towel or sterile lubricating gel to prevent fur from contaminating the wound during clipping. The wound should be clipped with wide margins of 3 to 5 cm to allow for bandages or closure and to fully assess the wound’s margins.

Once the wound has been adequately clipped of fur it should be flushed to reduce contamination and facilitate evaluation. A 1-L fluid bag placed into a pressure cuff inflated to 300 mm Hg, attached to a 16-gauge needle provides ideal pressure of 7 to 8 psi with which to flush the wound without causing further tissue damage and bacterial contamination (Gall and Monnet, 2010).