Lecture 17: Lacerations and Wound Management Flashcards
Where is the skin thickness on the equine body
Mane and tail
Skin tends to be thicker with ___ than young horses
Older geldings
Skin is thicker at the ___surface of the legs than the __surface
Extensor, surface
Head, neck and body wounds heal better than wounds on __
Extremities
Prolonged healing in wounds of the extremities is due to ___ (4)
- Reduced vascularity
- Increased infection
- Increased inflammatory response
- Reduce regional temperature
Equine cleavage lines are parallel to ___
Predominant orientation of collagen fibers
Wounds that are parallel to ___have less tension
Cleavage lines/ langer lines of tension
When possible incisions should be made parallel to ___
Cleavage lines
Distal limb wounds are below the ___
Carpus tarsus
What is the most important step in wound therapy
Wound assessment
What are the steps in initial wound preparation
- Aseptic/sterile conditions (joints) vs simple clean technique
- Apply sterile water soluble gel to wound before clipping
- Clip hair over and around
- Rinse gel and hair from wound with sterile saline
- Explore wound
Debridement is an effective way to reduce ___within a wound and minimize ___
Bacterial load, necrotic tissue
What is the #1 choice for debridement
Sharp
What is the least traumatic debridement technique to tissues
Autolytic
What is a major disadvantage to sharp debridement
Once tissue is removed, can’t put that back
What is the least traumatic sharp debridement tool and should be used whenever possible
Scalpel
What are the two critical components for lavage
- Solution used
2, delivery
What solutions are used for lavage
Non-cytotoxic solution- saline, vetericyn, lacerum
How do you deliver a lavage
Need appropriate pressure and volume without pushing dither into wound—> use 19G needle or Catheter attached to 35mL syringe
What is a wet-to-wet dressing more effective at removing than gauze
Necrotic tissue and causes less damage to epithelial cells
What is a wet-to dry dressing
Dressing directly on wound bed is moistened with saline, rest of bandage is dry
Absorbent secondary layers pull fluid from primary dressing
What is a disadvantage to wet to dry dressings
Primary dressing often dries out between changes, when removed get non-selective debridement
What should chemical debridement be used for
Very contaminated wounds because not-selective
What are 2 chemical debridement agents
Hydrogen peroxide, hypertonic saline
What is a method of biological debridement
Sterile medical grade larvae/maggots
Larvae digest only ___tissue and ___, leaving healthy tissue unharmed
Necrotic tissue and pathogenic bacteria
Larval secretions also have ___effects and promote ___
Antibacterial, angiogenesis
What is autolytic debridement
Leave wound fluid intact with wound bed. WBC’s and enzymes from dead WBC’s affect only necrotic tissue, leave healthy cells intact, reduce bacterial count
Autolytic debridement can only occur in ___wounds
Dry
What is contamination of a wound
Presence of bacteria in wound without active multiplication or trauma to host
What is colonization of a wound
Bacteria are attached to tissue and multiplying but not necessarily causing trauma
What is an infection of a wound
Bacteria invade healthy tissue and actively multiply overwhelming host immune response
What is qualitative assessment of bacteria in wounds
Determine types of bacteria in wound, sensitivity testing, guides antibiotic decision
Sensitivity testing is especially important for wounds involving ___
Synovial structures
Antiseptics are effective against a broad range of bacteria but do not penetrate __and are unlikely to reduce ___in wound bed
Necrotic debris, bacterial populations
Antiseptics should be reserved for use on ___, not on ___
Normal skin surrounding wound, not on wound bed itself
Topical antimicrobial agents target __
Specific bacteria
Blood supply to wound surface is diminished in chronic infections so ___is required
Topical antimicrobial
In what stages are wounds best candidates for primary or delayed primary closure
Inflammatory or debridement phase, wounds that are clean or clean contaminated
What type of closure is used in new wounds that are clean
Primary closure
In primary closure the wound is closed ___ and using strict ___technique
Immediately, aseptic
Which closure provides the best functional and cosmetic result
Primary closure
Primary closure is acceptable for what types of wounds
Minimal tissue loss, minimal bacteria contamination and minimal tension
What suture patterns can be used to reduce tension
- Near-far-far-near
- Interrupted vertical mattress +/-stents
- Interrupted horizontal mattress +/- stents
To reduce tension use __diameter suture material
Large
Failure to obliterate dead space can lead to ___ which is excellent medium for ___
Hematoma/seroma, bacterial growth
What are some ways to close dead space
- Suture
- Meshing the skin
- Passive or active drains
- Pressure bandages
What is delayed primary closure
Wound is initially left open to allow for debridement and reduce bacterial contamination then closed primarily
When would you use primary for delayed primary closure
Primary when skin is thin and new wound, delayed when there is granulation tissue, thickening and lots of drainage
Identify which one you would use primary vs delayed primary closure on
left: primary (thin)
Right: delayed primary (lots granulation tissue, thick, lots of drainage)
When do you use second intention healing
Gross contamination and moderate to severe tissue loss makes closure hard
How does second intention healing work
Heal via contraction, granulation, and epithelialization
What is the best closure/healing technique for this wound
second intention healing- not enough skin to close
The ideal wound dressing keeps the wound bed __ and surrounding skin ___
Moist, dry
What type of wounds is hypertonic saline wound dressing good for
Necrotic and heavily exudative wounds
Hypertonic saline is a ___debdridement
Non-selective chemical debdridement
Hypertonic saline as a wound dressing is food for ___
Abscesses
How does Mankua honey work as wound dressing
Bacteriocidal and growth factor like effects
How do antimicrobial dressings work
Suppresses microbial penetration and growth, bacterial death occurs by destabilization and disruption of cytoplasmic membrane
T or F: bacteria can become resistant to antimicrobial dressings
False
Hydrogels are good for dry wounds because they __
Provide moisture
Hydrogels are excellent for promoting ___, ___ and ___
Autolytic debridement, WBC migration, and thermal regulation
Calcium alginate is best if used during what phase of wound repair
Granulating phase
How does calcium alginate wound dressing work
Calcium in dressing interacts with sodium in wound making an exudate that stimulates myofibroblasts and epithelial cells
What important structures are you worried about in head injuries
Brain, eyes, ears, paranasal sinuses, salivary ducts, nerves
What are the diagnostic aids for head wounds
Rads, ultrasound, CT, MRI
Always perform a ___ for a head wound
Neurological exam
If the orbit in involved in head wound determine ___and ___involvement
Bone and glove
What scrub do you not use for head wounds involving the orbit. What is better option
Don’t use chlorine iodine
Use betadine
How are eyelids closed
Primary closure using small diameter, absorbable sutures in many layers
How are ear wounds closed
Primary closure
What sinuses are affected in head wounds
Frontal and maxillary
What are two common sequela of head wounds involving paranasal sinuses
Bone sequestration and eventual fistula formation
What structures do you need to examine for head wounds involving mandible
Salivary duct and incisor involvement
How can you test for salivary gland involvement in head wound
Feed horse and look for saliva coming out of wound
How do you tx head wounds involving nares
Thorough debridement and use of multiple layers of closure
If a nares wound is >7 days old what do you do
Heal via second intention
Wounds of the thorax should always be examined with ___technique to determine depth
Aseptic
For wounds to thorax listen for ___getting sucked into wound during inspiration
Air
___antibiotics if pleural penetration
Broad spectrum
What type of bandage can be applied for thorax wound
Stent bandage- sterile towel held on wound with sutures
If there is peritoneal penetration of abdomen what do you do and how do you tx
- Abdominal bandage
- Broad spectrum antibiotics
- Referral for abdominal explore
What is the major side effect of axillary lacerations
Subcutaneous emphysema
For axillary lacerations wound opens and fills with air when horse moves ___
Leg forward
For axillary lacerations you examine for __involvement that can lead to ___
Thoracic—> pneumothorax
How do you tx axillary laceration
Pack wound with sling bandage to reduce air accumulation
Limit horses movement
How do you determine if synovial structure/joint is involved in wound
Place needle into synovial structure at site distant from wound
Distend with sterile saline observe wound for fluid egress
If synovial structure is involved what do you do
- Primary closure if possible
- Lavage, IV antibiotics, local intravenous regional perfusion, intra-articular antibiotics, bandaging
What is intravenous regional perfusion when tx synovial structure involvement
Apply tourniquet above wound, and put in antibiotics so it stays local
Heel bulb lacerations can involve everything from __ to ___
Skin to coffin joint
What are some potential synovial structures involved in heel bulb lacerations
DDFT, tendon sheet, and/or coffin joint
How do you close heel bulb lacerations with no synovial involvement
Delayed primary closure because close to ground and easily contaminated
After closure of heel bulb laceration apply __
Foot cast, reduce motion
Chronic wounds have delayed expression of ___necessary for healing
Growth factors (PDGF, FGF)
What is the first step in treatment of chronic wounds
Preparation- clip hair, lavage, disinfect
After you clip and clean chronic wound what do you do next
Digital explore- search for foreign material, draining tracts that can cause it to to heal
Radiograph or ultrasound for FB
___should be suspected whenever a wound does not heal in anticipated time frame
Infection
What is surgical tx for chronic wounds
Surgical debridement- remove infected tissue and turn chronic wound into acute—> stimulates healing
What is a sinus tract
“Draining tract” a cavity or channel
Is the venous sinus normal or pathological
Normal
What is a pathological sinus tract
Channel that permits escape of pus through skin
What is a fistula
Abnormal passage or communication between 2 internal organs leading from an organ to the surface of the body
What is an entercutaneous fistula
Intestine through abdominal wall
What is a sinucutaneous fistula
Paranasal sinus through skin
What is wrong
Entercutaneous fistula
What is wrong
Sinucutaneous fistula
Sinus tracts commonly occur secondary to
Secondary to trauma and foreign bodies
Sinus tracts are frequently associated with a ___
Sequestrum
What is this
Sequestrum
What is a Sequestrum
Chip of bone that came off parent bone and is dying
___ should be suspected any time chronic sinus tract/drainage is encountered
Foreign body
How do you dx sinus tracts
Ultrasound
Radiographs
Positive contrast sonography
How do sinus tracts appear on ultrasound
Hyperchogenicity and acoustic shadows
Radiographs immediately rule out __as cause of sinus tract
Metallic FB
What do you see on rads with sinus tracts
Soft tissue swelling, thickening, gas densities, periosteal reactions
What diagnostic tool is useful for identifying radiolucent foreign bodies for sinus tracts
Positive contrast- sinography
What is treatment for sinus tracts
Removal of foreign body, explore tract with probe
Sinus tracts can be followed by following ___colored membrane
Dark purple
If you have sinus tract in head what do you need to consider
Dental problem
What is this
dentigerous cyst/ ear tooth
Horse presents with fistulous withers and pole evil what is your most likely differential
Brucellosis
What are the 3 main strategies for preventing bacterial infection of wounds
- Effective cleansing and debridement
- Appropriate use of dressings/bandages
- Appropriate dressing/bandage changing
What type of suture is best for wounds
Smallest diameter possible, monofilament, absorbable suture with surgeons knots
