Download open wound management for nurses/technicians

OPEN WOUND MANAGEMENT FOR NURSES/TECHNICIANS
Theresa W. Fossum DVM, MS, PhD, Diplomate ACVS;Tom and Joan Read Chair in Veterinary
Surgery, Texas A&M University
Wound management is commonly performed by nurses/technicians. This lecture will focus on
management of open wounds, which are often the most difficult wounds to treat and are those
that require the most expertise and time to achieve a good outcome.
Immediately after injury, or when the animal is brought for treatment, wounds should be covered
with a clean, dry bandage to prevent further contamination and hemorrhage. Life-threatening
injuries should be treated and the animal’s condition stabilized before further wound
management is undertaken. When appropriate during stabilization, bandages should be removed
and the wound assessed and classified as either contaminated or infected and as an
abrasion, laceration, avulsion, puncture, crush, or burn wound. The “golden period” is the first 6
to 8 hours between wound contamination at injury and bacterial multiplication to greater than 105
CFU per gram of tissue. A wound is classified as infected rather than contaminated when
bacterial numbers exceed 105 CFU per gram of tissue. Infected wounds often are dirty and
covered with a thick, viscous exudate.
Fundamentals of Wound Management
Temporarily cover the wound to prevent further trauma and contamination. Assess the
traumatized animal and stabilize its condition. Clip and aseptically prepare the area around the
wound. Culture the wound. Débride dead tissue and remove foreign debris from the wound.
Lavage the wound thoroughly. Provide wound drainage. Promote healing by stabilizing and
protecting the cleaned wound. Perform appropriate wound closure.
Abrasions are superficial and involve destruction of varying depths of skin by friction from blunt
trauma or shearingforces. Abrasions are sensitive to pressure or touch and bleed minimally. A
laceration is created by tearing, which damages skin and underlying tissue. Lacerations may be
superficial or deep and have irregular edges.
Avulsion wounds are characterized by tearing of tissues from their attachments and creation of
skin flaps. Avulsion injuries on limbs with extensive skin loss are called degloving injuries. A
penetrating or puncture wound is created by a missile or sharp object, such as a knife, pellet, or
tooth that damages tissue. Wound depth and width vary depending on the velocity and mass of
the object creating the wound. The extent of tissue damage is directly proportional to missile
velocity. Pieces of hair, skin, and debris can be embedded in wounds.
Crush injuries can be a combination of other types of wounds with extensive damage and
contusions to skin and deeper tissue. Burns may be partial- or full-thickness skin
injuries caused by heat or chemicals. Wounds less than 6 to 8 hours old with minimal trauma and
minimal contamination are treated by lavage, débridement, and primary closure. Generally, the
sooner treatment begins, the better the prognosis. Penetrating wounds should not
be primarily apposed without surgical exploration. Severely traumatized and contaminated
wounds, wounds older than 6 to 8 hours, or infected wounds should be treated as open wounds
to allow débridement and reduction of bacterial numbers.
Most wounds are surgically apposed after infection has been controlled; however, some wounds
heal by contraction and epithelialization (healing by secondary intention).
Often anesthesia is required for initial wound inspection and care. The objective of open wound
care is to convert the open, contaminated wound into a surgically clean wound that can be
closed. Aseptic technique, gentle tissue handling, and hemostasis are essential. Severely
contaminated or infected wounds should be cultured after initial inspection. The area surrounding
the wound should be widely clipped and prepped. The wound may be protected from clipped hair
and detergents by applying a sterile, water-soluble lubricant (K-Y Jelly) or by placing saline-
soaked sponges in the wound and covering with a sterile pad or towel. As an alternative, the
wound may be temporarily closed with sutures, towel clamps, staples, or Michel clips. Hair may
be clipped from the wound margin with scissors dipped in mineral oil to prevent hair from falling
into the wound. Povidone-iodine or chlorhexidine gluconate skin scrubs are used to prepare
clipped skin. The detergents in antiseptic scrubs cause irritation, toxicity, and pain in exposed
tissue and may potentiate wound infection. Alcohol is very damaging to exposed tissue and
should be used only on intact skin.
Initial wound management begins with removal of gross contaminants and copious lavage using
a warm, balanced electrolyte solution, sterile saline, or tap water (500 to 1000 ml). Sterile
isotonic saline or a balanced electrolyte solution(lactated Ringer’s solution) is the preferred
lavage solution. Tap water is effective and less detrimental than distilled or sterile water, although
it causes some hypotonic tissue damage (cellular and mitochondrial swelling). Wound lavage
reduces bacterial numbers mechanically by loosening and flushing away bacteria and associated
necrotic debris. Lavage may be facilitated by the use of noncytotoxic wound cleansers (e.g.,
Constant Clens, Kendall Co., Mansfield, MA; Allclenz Wound Cleanser, Healthpoint
iotherapeutics).
Generally, these cleansers are applied to loosen debrisand soften necrotic tissue during bandage
changes; they act as a surfactant, disrupting the ionic bonding of particles and organisms to the
wound and allowing them to be easily rinsed off with saline or balanced electrolyte solutions.
Lavage following application of these cleansers, however, is not necessary. Antibiotics or
antiseptics (e.g., chlorhexidine or povidone-iodine) in the lavage solution reduce bacterial
numbers; however, these agents may damage tissue.
Antiseptics have little effect on bacteria in established infections. Lavaging is preferred to
scrubbing the wound with sponges. Sponges inflict tissue damage that impairs the wound’s
ability to resist infection and allows residual bacteria to elicit an inflammatory response.
Bacteria are effectively removed from the wound surface by high-pressure lavage. Traditionally,
a 35- or 60-ml syringe and an 18-gauge needle have been thought to generate approximately 7
to 8 psi of pressure; however, it was recently shown that it generates presssures substantially
higher than this (18.4 ± 9.8 psi). The most consistent delivery method to generate 7 to 8 psi is a 1
L bag of fluid within a cuff pressurized to 300 mmHg (Fig. 16-3). Higher pressure (70 psi),
generated by pulsatile lavage instruments (i.e., Water Pik [Teledyne], Surgilav, or Pulsavac
débridement system), is more effective in reducing bacterial numbers and removing foreign
debris and necrotic tissue, but may drive bacteria and debris into loose tissue planes, damage
underlying tissue, and reduce resistance to infection. Bulb syringes or fluid bottle with holes
made in the cap do not generate enough pressure to remove bacteria and debris adequately.
Debridement
Healing is delayed if necrotic tissue is left in the wound. Devitalized tissue is removed from the
wound by débridement. Débridement involves removal of dead or damaged tissue, foreign
bodies, and microorganisms that compromise local defense mechanisms and delay healing. The
goal of débridement is to obtain fresh clean wound margins and wound bed for primary or
delayed closure. Devitalized tissue is removed by surgical excision, autolytic mechanisms,
enzymes, wet-dry bandages, or biosurgical methods. The extent of devitalized tissue usually is
obvious within 48 hours of injury.
TOPICAL WOUND MEDICATIONS
Topical Antimicrobials and Antibiotics
Antimicrobial agents and antibiotics eliminate or reduce the number of microorganisms in a
wound that destroy tissue. Topical rather than systemic antibiotics are preferred for open
wounds. Mildly or moderately contaminated wounds do not benefit from combined topical and
systemic antibiotic therapy; however, combined therapy is advantageous in heavily contaminated
wounds. Antibiotics applied within 1 to 3 hours of contamination often prevent infection.
Benefits of topical drugs should outweigh their cytotoxic effects.
Antibiotics used effectively as topical ointments or added to lavage solutions are penicillin,
ampicillin, carbenicillin, tetracycline, kanamycin, neomycin, bacitracin, polymyxin, and
cephalosporins. Once infection is established, topical and systemic antibiotics have no beneficial
effect in preventing suppuration of wounds undergoing closure. Wound coagulum prevents
topical antibiotics from reaching effective levels in tissues deep in the wound and also prevents
systemic antibiotics from reaching superficial bacteria. These wounds must be débrided to allow
antimicrobial access to bacteria.
Guide to Dressings Based on Purpose
Purpose of Product
Suggested Products
Cleanse wound
Noncytotoxic commercial cleanser; balanced
electrolyte or saline solution
Absorb exudate
Absorption beads, pastes, powders, and
pads:
Alginates
Foams
Hydrocolloids
Hydrogels
Composite dressings
Autolytic débridement: Cover wound to allow
endogenous enzymes in wound fluid to
selfdigest eschar and fibrinous slough
Same as above, plus transparent films
Chemically débride devitalized tissue
Enzymatic débridement agents: Granulex, live
yeast Preparation-H
Add moisture to wound
Hydrogel
Hypertonic saline dressing
Medicinal honey
Maintain moist wound environment
Hydrophilic ointments
Foam
Hydrocolloids
Hydrogels
Transparent films
Fill dead space
Absorption beads, pastes, powders, and
tapes:
Alginates
Hydrocolloid
Hydrogel
Foam
Reduce swelling to improve perfusion
Hypertonic saline
Prevent contamination
Biguanide-impregnated antimicrobial gauze
Occlusive
Semiocclusive
Reduce bacterial numbers
Biguanide-impregnated antimicrobial gauze
Antibiotics
Cover and protect wound
Non-adherent, hydrophilic dressing with
appropriate
intermediate and outer bandage layers
Protect surrounding skin from moisture and
trauma
Moisture barrier ointments
Skin sealants
Transparent film dressings
Bandage
Reduce odour
Vapor-permeable film or polyurethane foam
with activate charcoal