Exam 2: Lecture 12: Open Wound Management Flashcards
When should wounds be covered with a clean, dry bandage?
-Immediately after injury
-When the animal is brought for treatment
What should happen before further wound management than a clean, dry bandage is taken?
-Life-threatening injuries should be treated & the animal’s condition stabilized
What are the 9 fundamentals of wound management?
- Temporarily cover the wound to prevent further trauma & contamination
- Assess the traumatized animal & stabilize its condition
- Clip & aseptically prepare the area around the wound
- Culture the wound
- Debride dead tissue & remove foreign debris from wound
- Lavage wound thoroughly
- Provide wound drainage
- Promote healing by stabilizing & protecting cleaned wound
- Perform appropriate wound closure
What should happen to open or superficial wounds when appropriate during stabilization?
-Bandages should be removed
-Wound assessed & classified
How are wounds classified?
-Contaminated or Infected vs. Class 1-3
-Type of wound
What is the “Golden Period” when talking about wounds?
-First 6-8 hours between wound contamination at injury & bacterial multiplication to greater than 10^5 CFU per gram of tissue
When is a wound classified as infected rather than contaminated?
A wound is classified as infected rather than contaminated when bacterial numbers exceed 10^5 CFU per gram of tissue
How do infected wounds look?
-Often grossly dirty & covered with a thick, viscous exudate
What is contamination?
-Presence of microbes on a surface
What is colonization?
-Surface microorganisms are replicating
What is infection?
-Invasion & replication of microbes within the tissue
How do we calculate microbial burden?
-(Number of microorganisms x virulence) / Host resistance
What are the 3 main wound classifications?
-Class 1
-Class 2
-Class 3
What is Class 1 wound contamination?
-0-6 hours old
-Minimal contamination & tissue trauma
What is Class 2 wound contamination?
-6-12 hours old
-Microbial levels may not have reached critical level consistent with development of infection
What is Class 3 wound contamination?
-Older than 12 hours
-Microbial levels may have reached critical level consistent w/ development of infection
What are the different types of wounds?
-Abrasion
-Puncture wound
-Laceration
-Avulsion or Degloving Injury
-Thermal burn
-Decubital Ulcers
What are abrasions?
-Superficial & involve destruction of varying depths of skin by friction from blunt trauma or shearing forces
-Sensitive to pressure or touch & bleed minimally
How do abrasions heal?
-Heal rapidly by re-epithelialization
What are puncture wounds?
-Characterized by small skin opening with deep tissue contamination & damage
-Wound depth & width vary depending on object creating wound
The extent of tissue damage caused by puncture wounds is directly proportional to
-Missile velocity
What can be embedded in puncture wounds?
-Pieces of hair, skin, & debris
What are the mechanisms of injury for puncture wounds?
-Penetrating foreign objects (ex: stick, wire, bone)
-Bite wounds
-Gunshot injuries
What type of wound is shown?
-Puncture wound
What are lacerations?
-Created by tearing, which damages skin & underlying tissue (muscles, tendons)
-Lacerations may be superficial or deep & have irregular edges
-Typically, minimal peripheral trauma to the wound edges
What type of injury?
-Laceration
What are avulsions or degloving injuries?
-Characterized by tearing of tissues from their attachments & the creation of skin flaps
-Exposed wound bed
-Common on distal limbs
When are avulsion injuries called degloving injuries?
-Avulsion injuries on limbs w/ extensive skin loss are called degloving injuries
What is anatomic degloving?
-Skin & various levels of underlying tissue are torn off the limb
What is physiologic degloving?
-Skin surface is intact but separated or avulsed from underlying subcutaneous tissue & blood supply
What does physiologic degloving result in?
-Delayed necrosis of the skin
What type of injury is this?
-Avulsion or degloving injury
What are thermal burns?
-May be partial or full-thickness
-Caused by heat or chemicals
What are the mechanisms of injury for thermal burns?
-Fire
-Cage dryers
-Heating pads
-Heat lamps
-Hot liquids
-Malicious incidents
What type of injury is this?
-Thermal burns
Deep & extensive burn injuries may cause systemic compromise due to
-Severe fluid loss
-Electrolyte loss
-Protein loss
What risk is high in thermal burns?
-risk of infection & sepsis is high
Strict classification of burns is no longer in favor due to
-Delayed microvascular damage
What are crush injuries?
-Can be a combination of other types of wounds w/ extensive damage & contusions to skin & deeper tissue
What are decubital ulcers?
-Result of compression of skin & soft tissues between a bony prominence & a hard surface
-May extend into deeper soft tissue & bone
What do decubital ulcers result in?
-Skin loss over the bony prominence
When are decubital ulcers often seen?
-Often seen in recumbent animals
What are common sites for decubital ulcers?
-Greater trochanter
-Lateral elbow
-Lateral hock
What are the 4 types of wound closure?
-Primary Wound Closure (First Intention Healing)
-Delayed Primary Closure
-Healing By Contraction & Epithelialization (Second Intention Healing)
-Secondary Closure (Third Intention Healing)
What wound closure occurs in most surgical wounds?
-Primary wound closure (First intention healing)
What is primary wound closure (first intention healing)?
-Wound edges are apposed & allowed to heal by first intention
What is primary wound closure (first intention healing) indicated in?
(Class 1 & some Class 2)
-Clean sharply incised wounds
-Minimal trauma
-Minimal contamination
-Within hours of injury
What is delayed primary closure?
-Appositional closure within 3-5 days
-Before granulation tissue has been produced in wound bed
Delayed primary closure is indicated in
(Class 2 Wounds)
-Mildly contaminated
-Minimal trauma
-Require some cleansing, debridement, & open management before closure
What is healing by contraction & epithelialization (second intention healing)?
-Wound left open to heal by contraction & epithelialization
-Eventually produces continuous epithelial surface
What is healing by contraction & epithelialization (second intention healing) indicated for?
-Dirty wounds
-Contaminated wounds
-Traumatized wounds
(where cleansing & debridement are necessary, but primary or delayed closure is prohibited)
What do you have to do for healing by contraction & epithelialization (second intention healing)?
-Continually assess to see if secondary closure should be used to expedite the process
What is secondary closure (third intention healing)?
-Appositional closure more than 3-5 days after wounding
-Granulation tissue has formed in the wound bed
What is secondary closure (third intention healing) indicated in?
-Severely contaminated
-Severely traumatized
-Infected
What does development of granulation tissue in the wound bed in secondary closure (third intention healing) provide?
-A microbial resistant, vascular substrate that facilitates healing
How is secondary closure (third intention healing) closed?
-Closure is performed over the granulation tissue
-Some debridement may be necessary to facilitate closure
What type of wound closure is done before granulation tissue has been produced in wound bed?
-Delayed primary closure
What type of wound closure may be inefficient & fail to produce a functional outcome?
-Healing by contraction & epithelialization (second intention healing)
What type of wound closure allows for third intention healing?
-Secondary closure
What are we trying to accomplish with immediate wound closure?
-Reduce microbial burden
-Prevent further contamination
What immediate wound care is done in initial unstable patient?
-Copious irrigation (even w/ tap water) (solution to pollution is dilution)
-Coverage of wound w/ antimicrobial agent
-Area surrounding wound should be widely clipped & prepped
-Bandage to protect wound
What is often required for immediate wound inspection & care?
-Anesthesia
What wounds should be cultured after initial inspection?
-Severely contaminated or infected wounds
How can you protect the wound from clipped hair and detergents?
-Applying a sterile, water-soluble lubricant (K-Y Jelly) or by placing saline-soaked sponges in the wound & covering w/ sterile pad or towel
-Hair can be clipped from wound margin w/ scissors dipped in mineral oil to prevent hair from falling into wound
How can we temporarily close a wound?
-Sutures
-Towel clamps
-Staples
-Michel clips
What scrubs are used to prepare the clipped skin around the wound?
-Providone-iodine or chlorhexidine gluconate skin scrubs
Why do we not use antiseptic scrubs to prepare clipped skin around the wound?
-Detergents in antiseptic scrubs cause irritation, toxicity & pain in exposed tissue & may potentiate wound infection
____ is very damaging to exposed tissue and should be used only on intact skin
alcohol
What is the preferred lavage solution for initial wound management?
Sterile isotonic saline or a balanced electrolyte solution (lactated Ringer’s solution)
What lavage solution is effective and less detrimental than distilled or sterile water?
-Tap water
What does wound irrigation do?
-Wound lavage reduced bacterial numbers mechanically by loosening and flushing away bacteria & associated necrotic debris
What can facilitate lavage?
Use of noncytotoxic wound cleansers
-Applied to loosen debris & soften necrotic tissue during bandage changes
What do noncytotoxic wound cleansers do to facilitate lavage?
-Act as surfactant, disrupting ionic bonding of particles & organisms to the wound & allowing them to be easily rinsed off w/ saline or balanced electrolyte solutions
What can you put into the lavage solution to reduce bacterial numbers, but what can this also cause?
Antibiotics or antiseptics (e.g. chlorhex or iodine)
-These agents may damage tissue
-Antiseptics have little effect on bacteria in established infections
Which is preferred, lavaging or scrubbing the wound with sponges?
Lavaging is preferred to scrubbing the wound w/ sponges
-Sponges inflict tissue damage that impairs wound’s ability to resist infection & allows residual bacteria to elicit inflammatory response
What is the most consistent delivery method for wound irrigation?
-Most consistent delivery method to generate 7-8 psi is a 1-liter bag of fluid within a cuff pressurized to 300 mmHg
What is higher pressure (70 psi) wound irrigation and what can it do?
-Generated by pulsatile lavage instruments & more effective in reducing bacterial numbers & removing foreign debris & necrotic tissue
-MAY: drive bacteria & debris into loose tissue planes, damage underlying tissue, reduce resistance to infection
Why is debridement important?
-Healing is delayed if necrotic tissue is left in wound
-Devitalized tissue is removed from wound by devridement
What does debridement involve?
Removal of dead or damaged tissue, foreign bodies, & microorganisms that compromise local defense mechanisms & delay healing
What is the goal of debridement?
To obtain fresh clean wound margins & wound bed for primary or delayed closure
In debridement, how is devitalized tissue removed?
-Surgical excision
-Autolytic mechanisms
-Enzymes
-Wet-dry bandages
-Biosurgical methods
The extent of devitalized tissue is usually obvious within _____ hours of injury
-48
During surgical debridement, how should devitalized tissue be surgically excised?
-In layers beginning at the surface & progressing to the depths of the wound
How is surgical debridement done?
-Sharp dissection
-Electrosurgery
-Laser
What must be preserved during surgical debridement?
-Bones
-Tendons
-Nerves
-Vessels
How should muscle be surgically debrided?
-Until it bleeds & contracts w/ appropriate stimuli
Extensive surgical debridement of ____ should be avoided because it may delay wound healing (particularly in cats)
subcutaneous tissue
______ ______ should be liberally excised in surgical debridement b/c it is easily devascularized & harbors bacteria
Contaminated fat
_____ ____ should be spared in surgical debridement to maintain the viability of overlying skin
Cutaneous vessels
If sufficient healthy tissue surrounds the wound & vital structures can be preserved, what is an alternative to surgical debridement?
-Entire wound can be excised en bloc
What is the danger of surgical debridement?
-Removal of excessive amount of possibly viable tissue
With penetrating wounds or punctures, it may be necessary to ______ to assess the extent of injury and allow debridement
-May be necessary to enlarge the wound
When should wounds be closed after surgical debridement?
-When it appears healthy or when a bed of healthy granulation tissue has formed, unless wound closure by contraction & epithelialization is anticipated
What is autolytic debridement?
-Much slower process
-Accomplished through creation of moist wound environment to allow endogenous enzymes to dissolve nonviable tissue
-Often preferred over surgical or bandage debridement in wounds w/ questionable viability
How is autolytic debridement accomplished?
-With hydrophilic, occlusive, or semiocclusive bandages (allow wound fluid to remain in contact w/ nonviable tissue)
What happens to dressings that are allowed to dry on the wound, such as wet-to-dry bandages or dry-to-dry bandages?
-Adhere to wound surface & pull debris & strip superficial layers off the wound bed when removed
In addition to mechanical debridement, what do wet-to-dry wound dressings also do?
-Provide adequate wound protection & coverage
-Maintain moist wound environment
-Absorb moderate amounts of wound exudates
When are bandage (mechanical) debridement dressings most effective?
-In early stages of wound healing or in management of wound infection
What is enzymatic debridement used as & what needs to happen for it to produce the desired effect?
-Adjunct to wound lavage & surgical debridement
-Enzymes must remain in contact w/ wound for adequate time to produce desired effect
Enzymatic debridement is beneficial in what patients?
-Patients that are poor anesthetic risks
-Patients when surgical debridement may damage healthy tissue necessary for reconstruction
What can happen with enzymatic debridement?
-Local tissue irritation may occur
What is biosurgical debridement?
-Maggot therapy using greenbottle fly larvae
-Sterile medicinal maggots are bred specifically for biosurgery
When is biosurgical debridement (maggot therapy) best suited?
-To necrotic, infected, or chronic nonhealing wounds
What type of wounds typically benefit from antibiotic therapy?
-Severely contaminated, crushed, or infected wounds, or wounds older than 6-8 hours
How should antibiotics be selected for wound antibiotic therapy?
-Antibiotic selection should ultimately be based on culture & susceptibility testing
What topical antimicrobials and antibiotics should not be used in wounds?
-Powders b/c they act as foreign bodies
What type of antibiotics are preferred for open wounds?
-Topical rather than systemic antibiotics
What is important to note about triple antibiotic ointment in wound healing?
-The ointments is more effective for preventing infections than for treating them
What is the drug of choice to treat burn wounds?
-Silver sulfadiazine
What does silver sulfadiazine do?
-Effective against most gram + and gram - bacteria & most fungi
-Serves as antimicrobial barrier
-Can penetrate necrotic tissue
-Enhances wound epithelialization
What is nitrofurazone?
-Broad-spectrum antibacterial & hydrophilic properties
-Little effect against Pseudomonas spp.
-Hydrophilic properties
What is gentamicin sulfate?
-Espeically effective in controlling Gram-negative bacterial growth
-Often used before & after grafting and for wounds that have not responded to triple antibiotic ointment
What does cefazolin do for wound healing?
-Effective antimicrobial against gram-positive and some gram-negative organisms
-Topical cefazolin provides high levels of antibiotic in wound fluid
When should honey be used in wound healing?
-Should be used early in the course of wound healing and discontinued once a healthy granulation bed is present
Why would we use sugar in wound healing?
Has similar hypertonic effects to honey and
-Attracts macrophages
-Accelerates sloughing of devitalized tissue
-Provides cellular energy source
-Promotes formation of healthy granulation bed
What are the benefits of vacuum assisted closure?
-Increased rate of granulation
-Accelerated healing times
-Wound cleaning
-Improved blood flow
-Reduced edema
What is shown here?
-Vacuum assisted closure
