Wounds Flashcards
Classification of Operative Wounds
Clean
Clean-Contaminated
Contaminated
Dirty
Clean Wound
Surgically created wound
No infection encountered
Aseptic technique maintained
No structure normally containing bacteria opened
Clean Contaminated Wound
Surgically created wound but Hollow viscus or organ normally containing bacteria is opened but no contents are spilled
Minor break in technique
Contaminated Wound
Surgical wound but Hollow viscus is opened with gross spillage
Major break in technique
What is an example of Contaminated Wound?
Traumatic wound
Dirty Wound
Contain pus
Contain contents of perforated hollow viscus
What is the goal of aseptic technique?
minimize the incidence of surgical wound infection
What is the Rule of Thumb for surgical wound infections?
Risk doubles every hour
What factors lead contamination to infection?
Microbial pathogens
Local wound environment
Host Defense mechanisms
Sources of Operative Wound infections
The operating room environment
The operating team
Surgical instruments and supplies
What is the most common source of operative wound infections?
Patient’s endogenous flora
Surgical Site Infection
Infection at the surgical site occuring within 30 days of surgery or up to 1 year with implants
Prophylactic Antibiotic administration
Administration prior to wound contamination
Therapeutic Antibiotic Administration
treatment of an infection already present
At what time do you administer prophylactic antibiotics?
30-60 minutes prior to skin incision
When do you administer Prophylactic antibiotics?
When unexpected contamination occurs during surgery or surgery is longer than expected
What type of antibiotics should be administered for therapeutic treatment of surgical wounds?
An antibiotic that covers the four quadrants of bacteria
What are the four quadrants of bacteria?
Gram positive
Gram negative
Aerobes
Anaerobes
How do you minimize perioperative infections?
Protect incision lines
Wash hands between patients, gloves preferred
Remove catheters and drains as soon as no longer needed
What are the common wound etiologies?
Lacerations Bite Wounds Degloving injuries Sinus tracts Burns toxins Nonhealing wounds
Bite wound considerations
Which ones need to be treated aggressively? Size Number of animals Location Clinical assessment of severity
Passive (Penrose) drain
manages dead space
Monitor character of wound exudate
Active Drain
Monitor the character of peritoneal fluid
Degloving Injuries
Shearing forces which sever cutaneous vessels supplying skin
Physiologic Degloving
Skin devitalized but still in place
Anatomic Degloving
Skin avulsed from underlying tissue
What are the types of Burns?
Thermal
Chemical
Electrical
Examples of Thermal Burns
House fires
Hot liquids
Direct contact to a hot object
What are the topical treatments for Burns?
Aloe vera
Silver sulfadiazine
Why do we use Aloe vera to treat burn wounds?
Anti-inflammatory
Why do we use Silver Sulfadiazine to treat burn wounds?
Antibacterial
What is the initial treatment for burn wounds?
Cool injured tissue Topical treatment of Aloe Vera and Silver Sulfadiazine Analgesics Fluid Resuscitation Wound debridement Hydrotherapy
Causes of Non-healing wounds?
Foreign bodies Immunodeficiency Pathogens Concurrent disease Nutritional status Drugs
What types of foreign bodies are not tolerated and must be removed?
Porous and organic materials
What types of foreign bodies are tolerated and do not have to be removed unless they are contaminated?
Glass
gravel
steel or lead pellets
carbon
What are the sources of contamination for a Traumatic wound?
Endogenous flora
Accident site
Hospital
What are examples of the locations of endogenous flora?
Skin
Excretions (feces)
What are the factors influencing development of infection?
Number and type of bacteria
Hose defense mechanisms
Exogenous factors: Foreign bodies and soil infection potentiating factors
“Golden Period”
time from contamination until bacteria invade and replicate to greater than 1000000/gm of tissue
generally 6-8 hours
Infection potentiating factors
Negatively charged particles with large surface area
Inactivate Neutrophils
Bind to positively charged antibiotics
Clays and organic soil components`
Initial Management of Traumatic Wounds
Thorough examination of the wound
Debridement
Wound Lavage
What do you use KY jelly for during wound preparation?
Used to lubricate the wound and makes it easier to remove hair from the wound
Use of a Bulb Syringe
useful for keeping tissues moist but ineffective for removing bacteria and foreign bodies
Use of Water Pik
produce pressure high enough to damage tissue and drive bacteria into wound
Wound Lavage Solutions
Tap Water Balanced electrolyte solutions Wound cleansers Antiseptic solutions Antibiotics
When do you use Balanced electrolyte solutions?
used once granulation tissue fills the wound
When do you use Antiseptic solutions?
Wounds in lag phase or still contaminated/infected
All are cytotoxic
What are the antiseptic solutions?
Chlorohexidine
Povidone-Iodine
Dakin’s solution (dilute bleach)
When do you use Antibiotics for wound lavage?
acute wounds prior to bacteria invading tissue
When do you use Povidone-Iodine?
Broad spectrum: gram positive and gram negative, viruses, yeasts, and fungi
What are the disadvantages of Povidone-Iodine?
Forms inactive complexes with organic matter
Systemic absorption - toxicity
What is the mechanism of action of Povidone-Iodine?
Works on cell walls
What are the advantages of Chlorhexidine?
Activity less affected by organic matter
Long residual action: twice daily application and residual activity increases with repeated applications
Side-effects uncommon
What Chlorhexidine solution is more tissue friendly?
Chlorhexidine gluconate
What Chlorhexidine is more frequently used?
Chlorhexidine diacetate
In what species are hypersensitivity reactions to Chlorhexidine common in?
Cats
What happens if Chlorhexidine is diluted in anything but sterile water?
It forms a precipitate
Debridement
Removal of devitalized tissue and foreign bodies
What are the methods of debridement?
Surgical Autolytic Chemical Mechanical Biosurgical
Autolytic debridement
Moisture retentive dressings
Mechanical debridement
Adherent primary dressing
What are the two types of Biosurgical debridement?
Chronic/non healing wounds
Maggot Therapy
What are the two types of surgical debridement?
Layered
“En bloc”
What is the most commonly used method of surgical debridement?
Layered surgical debridement
“En bloc” surgical debridement
complete excision of wound as with tumor excision
What are the indications for Chemical debridement?
Poor anesthetic risks
Minimal debridement of open wounds
when surgical debridement may damage important structures
adjunct to other methods
Trypsin
debriding agent
Castor Oil
Minimizes tissue desiccation
Balsam of Peru
Stimulates capillary formation
When is mechanical debridement indicated?
wound in lag phase with heavy contamination or thick viscous exudate
Mechanical debridement
Devitalized tissue and foreign bodies trapped in primary bandage layer
Necrotic tissue and debris pass into or attach to dressing as fluid is absorbed by bandage
Open Wound Management indication
wound considered inappropriate for closure after initial wound lavage and debridement
unable to remove all devitalized tissue/foreign bodies
Viability of tissue questionable
Concerns about infection due to contamination
Amount of wound exudate
Tissue edema/swelling
Patient condition
When do you use Negative Wound Pressure Therapy?
Acute wounds: Used after surgical debridement to promote more rapid granulation tissue formation
Chronic wounds: improve local environment to enhance second intention healing
Negative Pressure Wound Therapy
Constant or intermittent suction applied to wound
Used on wounds in late lag phase or early proliferative phase of wound healing
What are the benefits of Vacuum-Assisted Closure?
Increased tissue blood flow
Decreased interstitial edema
Decreases bacterial burden in wound
may help remove inflammatory cytokines from wound
Accelerated granulation tissue formation
Less frequent bandage changes
Calcium Alginate
Nonwoven felt-like material derived from seaweed
Extremely hydrophilic-fluid absorption
Promotes autolytic wound debridement and wound healing
Aids in hemostasis
When do you use Calcium Alginate?
wound that is healthy but secreting moderate to heavy exudate in early stages of healing
A wound that is not adequately debrided but not amenable for closure
Honey Properties
Cleanses wound
Hygroscopic
Promotes granulation tissue formation
Antibacterial/Antifungal
What are the reasons for the Antibacterial/ Antifungal properties of Honey?
Osmotic effect
Low pH
“Inhibine” production
Unidentified phytochemical component in some honeys
What is the primary antibacterial effect of sugar due to?
Osmolality
Sugar properties
Cleanses wound and reduces edema
Promotes granulation tissue formation
What is the most important cell for wound healing?
Macrophages
What are the actions of Maltodextrin?
Chemotactic for PMNs, lymphocytes, macrophages
Provides energy for cells
Stimulates more rapid granulation tissue formation and epithelialization
Antibacterial properties
When do you use Maltodextrin?
Deep wounds
Wet to Dry dressing indications
Necrotic tissue and/or foreign bodies
High viscosity exudate
How does Wet to Dry dressing work?
Liquify viscous exudate enhancing entrapment in dressing
Used with fibrinous exudate which will mobilize the exudate into the dressings to be removed
When is Dry to Dry Dressing used?
used as an adherent topical dressing to aid wound debridement
especially highly exudative wounds (serous fluids)
Degloving injuries
Bite wounds
Lacerations
Deep “cavity” wounds
Disadvantages of Adherent Dressings
Bacteria can flourish in moist environment
Wet dressings can cause maceration of surrounding skin
If bandage soaks through bacteria can move into or out of bandage
Porous Non or Low Adherent Dressings indications
Protect sutured wounds
Wound in reparative stage: Healthy granulation tissue, Serosanguineous exudate, Epithelial migration from margins
Nonadherent dressings advantages
Keep wound moist
Allow excess fluid to drain
Do not damage newly formed reparative tissue when bandage is changed
Moisture Retentive Dressing
Typically hydrocolloid or polyurethane dressings
Better than adherent dressings for wounds in late debridement/ proliferative phase because they optimize the body’s inherent wound healing abilities
Maintain the normal physiologic ratios of proteases, protease inhibitors, growth factors, and cytokines
Oclusive
will seal around the wound and not let anything in or out
Semi-oclusive
will allow some exudate in and out
MVTR
Moisture Vapor Transmission Rate
Moisture Vapor Transmission Rate
Ability to transmit moisture, vapor, and gases from wound to atmosphere
What are the examples of Biological Dressings?
Equine Amnion
Xenografts and Allografts
Extracellular matrix-derived: Collagen, PSIS, and PUBS
What is the disadvantage of Equine Amnion?
Limited storage time for 6 months and only available during a certain time of the year
PSIS
Porcine Small Intestinal Submucosa
Porcine Small Intestinal Submucosa
a natural resorbable biocompatible scaffold which potentiates appropriate tissue remodeling
Reinforces wound tissue and is absorbed by the body as it is replaced by host tissues
What is an advantage of PSIS?
will take on the characteristics of the surrounding tissue
What are the indications for PSIS?
Degloving injuries and other large skin defects containing healthy tissue
Biological dressing until definitive reconstruction
Dermal substitute to “guide” wound repair when used in reparative stage of wound healing: inhibits wound contraction, Epithelialization will predominate over contraction, Complete healing may take longer than second intention healing
Primary Closure
Immediate closure of wound
What type of wounds can you use Primary closure on?
Clean wounds
Clean-contaminated wounds
Clean contaminated wounds
intact host defense mechanisms
Healthy wound
Appropriate antimicrobial treatment
What are the advantages of using CO2 laser?
Good visualization
Good Hemostasis
What are the disadvantages of using a CO2 laser?
Takes longer as opposed to cold steel
Delayed Primary Closure
Wound left open for 2-5 days
Closed prior to visible formation of granulation tissue
What types of wounds are Delayed Primary Closures performed on?
Traumatic wounds that need to be debrided or assessed
Secondary Closure
Wound closure after granulation tissue covers the wound
What types of wounds are secondary closures performed on?
Deep narrow wounds
Wide wounds
What suture pattern do you use on a wound without a lot of tension with a short or irregular wound?
Cruciate
What suture pattern do you use on a wound without a lot of tension with a straight wound?
Ford Interlocking
What are the disadvantages of Second intention wound healing?
the cosmetic appearance or the quality of healing
How well does a wound with less than 25% circumference of the leg heal?
should heal well
How well does a wound with 25-33% circumference of the leg heal?
Most heal well
How well does a wound with 33-50% circumference of the leg heal?
will probably heal with wider scar
Consider techniques to facilitate closure
How well does a wound with a greater than 50% circumference of the leg heal?
Consider reconstruction
Extended healing time or inadequate healing
What are the reasons for cessation of wound contraction?
Wound has healed
Tension in surrounding skin exceeds pull of myofibroblasts
Collagen deposition in chronic wound interferes with pull of myofibroblasts
What are the complications of second intention healing?
The quality of the healing might not be that great
May get chronic lymphatic accumulation in the lower limb
Epithelialization can be thin and damaged easily
Primary contraction
Retraction of skin edges after tissue is cut
What is the ability to undermine the skin influenced by?
- Species: differences in blood supply to skin
2. Breed - dogs - some have more loose skin than others
What is the purpose for using walking sutures?
Advance the skin over the wound
Distribute tension
Decrease dead space
What are the techniques for enhancing local movement of skin?
Skin stretching: Skin expanders, Skin stretching devices, presuturing
Releasing incisions
Multiple punctate relaxing incisions
Adjustable horizontal mattress sutures
Presuturing
takes advantage of the properties of mechanical creep and stress relaxation
What types of wounds do you use Adjustable Horizontal Mattress?
wounds with established granulation tissue and skin at edge of wound is thicker and holds suture better
What do you use with Adjustable Horizontal Mattress?
Monofilament suture material
Buttons
Split-shot
