Wounds (E1) Flashcards
What are the 4 classifications of operative wounds?
Clean
Clean-contaminated
Contaminated
Dirty
You perform surgery in the abdomen and penetrate an organ in the GIT, what would would differentiate a clean-contaminated wound from a contaminated wound? What would make it a dirty wound?
Clean-contaminated: Spillage of the GIT contents
Dirty: If the punctured organ contained pus
As a rule of thumb, with every hour of surgery the risk of infection increases by ___%
100 (it doubles)
T/F: Classifying a wound as “dirty” implies infection.
True
What is the most common cause of peritonitis in small animals?
Ruptured/punctured GIT
T/F: Hypothermia intra-operatively does not increase nor decrease the risk of infection.
False, increases
What is the most common source of operative wound infections?
The patient’s endogenous flora (GIT, skin)
If prophylactic antibiotics are indicated, how long prior to the incision of the skin should it be administered? How long should administration be continued?
30-60 minutes (best while patient is awake)
Continue for no longer than 24 hours
How does healing of superficial wounds differ in dogs and cats?
In cats, the SQ tissue is important for wound healing and needs to be preserved whenever possible. If it does need to be removed, expect it to take longer to heal.
In dogs we can be more aggressive in debriding away the SQ tissue.
T/F Prophylactic or preventative antibiotics are given before the animal is induced.
False, preventative is given intra-operatively.
What is the difference between an anatomic and a physiologic degloving?
In an anatomic the skin is avulsed
In a physiologic the skin is devitalized but still in place (an eschar)
What is one risk of leaving devitalized skin in place on a degloving wound?
What is a benefit of leaving it in place?
Risk: Bacteria can collect underneath it
Benefit: Acts as a short-lived bandage, minimizes amount of open wound
Using the rule of 9s, what is the extent of burn when the entire forelimb is affected?
9%
What are 2 topical treatment options for initial burn management?
Aloe vera
Silver sulfadiazine
Usually used together
T/F: Hydrotherapy is a good option for early burn wound management if it is a full thickness burn.
False, partial thickness
Burns >___% TBSA are often associated with significant complications and prolonged treatment.
50
What virus predisposes animals, especially cats, to non-healing wounds?
Retrovirus (causes immunodeficiency e.g. FIV, FeLV)
T/F: A piece of glass or a tooth pick are examples of foreign bodies that are well-tolerated and do not necessarily need to be removed.
False, organic materials are poorly tolerated so the tooth pick must be removed (glass is ok)
A ____ is a communication between a mesothelial surface and the skin, while a ____ is a communication between two epithelial surfaces that is lined by epithelium.
Sinus (mesothelial Surface to Skin)
Fistula (Latin for FLUTE/tube, open on both ends)
In an altered female dog with a draining tract in the caudal abdomen, what differential other than a foreign body must you consider?
Granulation tissue/infection caused by a suture reaction from the spay
Given that prophylactic antibiotics are indicated for your patient, what antibiotic would you give if the most likely source of contamination is the skin? What is it is the GIT?
Skin- Cephalexin/Cefazolin
GIT- Cefoxitin (2nd generation cephalosporin)
Using the rule of 9s, what is the extent of burn when the entire hindlimb is affected?
18%
What is the “Golden Period”?
The 6-8 hours after injury before bacteria invades and begins to replicate
What do you call negatively charged particles with a large surface area that may worsen an infection? How do they work?
Infection Potentiating Factors (IPFs)
MOA: Inactivate neutrophils
T/F: Up to 90% of bacteria can be removed with proper wound lavage.
True
Why are bulb syringes not effective in removing bacteria and foreign bodies from wounds?
Not enough pressure
What dilution of Povidone-Iodine should be used for wound lavage? How long is the residual activity?
1:10 or less
4-6 hours
Which has longer residual activity, Povoidone-iodine or chlorhexidine?
Chlorhexidine (residual activity = 8-12 hours, also increases with repeated applications)
What is the most common method of surgical debridement, Layered or En Bloc?
Layered
What is Granulex?
Enzymatic (chemical) debridement solution or spray containing trypsin, castor oil and Balsam of Peru.
Granulation tissue is primarily _____ and ______.
Collagen
Capillaries
T/F Negative Wound Pressure therapy is used only with acute wounds.
False
What can you use to speed up the formation of granulation tissue in a wound? What about over exposed bone?
Vacuum-assisted closure (VAC)
Cortical fenestration
What does it indicate when granulation tissue over a distal limb wound with exposed bone does not heal over all of the bones?
The bone(s) over which no healing is occuring is devitalized bone
What topical wound dressing that changes from a felt-like consistency to a gel, promotes autolytic wound debridement and wound healing as well as aiding in hemostasis?
Calcium alginate
Systemic effects can be see if the extent of the burns is >__% TBSA. This is also when fluid resuscitation is warranted.
15
A dog comes in a few days after finishing her course of antibiotics following the appearance of a sinus tract because the tract has re-opened. What do you think happened?
Foreign body is still in there (pseudo-healing occurred)
What pressure is ideal for lavaging a wound?
7-8 psi
T/F Not all antiseptic solutions are cytotoxic, this is why care must be taken when choosing which one to use when cleaning a wound.
False, all are cytotoxic
Instilling dilute ______into a draining tract prior to surgery makes following the tract easier.
Methylene blue
Which topical wound dressings promote granulation tissue formation by attracting macrophages?
Granulated sugar and Maltodextrin
What type of adherent dressing is indicated for wounds with devitalized tissue and/or foreign bodies, especially if the exudate is highly viscous?
Wet-to-dry
What kind of bandage/dressing can you use if a circumferential bandage is not possible?
Tie-over dressing
When should adherent dressing be discontinued?
Once the wound bed is healthy
What type of dressing is indicated for wounds in late debridement/proliferation phase to optimize the body’s inherent wound healing abilities? What type of wound debridement does this promote?
Moisture retentive dressings (Hydrocolloid or polyurethane)
Autolytic debridement
What is the biological dressing is obtained from horses?
Amnion
Which side of a PSIS (Porcine Small Intestinal Submucosa) wound dressing is applied to the wound surface, rough or smooth?
Rough
What are the 4 wound closure classifications?
Primary closure
Delayed primary closure
Secondary closure
Contraction and epithelialization (second intention healing)
What type (thickness) of burn is it if hair epilates easily from the burn wound?
A full thickness burn
What are the 3 reasons wounds stop contracting?
It has healed
Tension in surrounding skin exceeds pull of myofibroblasts
Collagen deposition in chronic wounds interferes with pull of fibroblasts
Almost any configuration of wound shapes heals well, except for which shape?
Circle
T/F Chlorhexidine can be diluted in any solution and should not be used unless diluted.
False, only in sterile water otherwise forms precipitates (salts)
What method of debridement involves the use of adherent dressings, such as wide mesh gauze?
Mechanical
What modality can be used to detect a plant-based foreign body in a wound? Can it be used intraoperatively?
Ultrasound
Yes
Incisions and wound closures on the trunk should be made ____ to skin tension lines if possible. This decreases lateral tension, accelerates healing and will create a more narrow scar.
Parallel
What are some potential complications of large open wounds?
Fluid loss
Hypoproteinemia
Infection
Undermining skin on the thorax is done below the __________ muscle to maintain the blood supply to the skin.
Cutaneous trunci
T/F: It is easier to undermine skin and re-position it to close a wound if the dog is fat because the skin is stretched out.
False, skinny is easier
What are the SQ sutures called that are placed when closing a wound to distribute tension and decrease dead space?
Walking sutures
What do you call sutures that are placed to take advantage of mechanical creep and stress relaxation and stretch the skin so the wound can be closed?
Presuturing
What is the technique called that involves creating multiple smaller wounds to help heal a sutured incision?
Punctuate relaxing incisions
Does a adjustable horizontal mattress work better for an acute or chronic injury?
Chronic
What is indicated if dead space can not be obliterated and fluid accumulation is likely?
Surgical drain placement
What topical wound dressing is antibacterial and antifungal, has an osmotic effect (so good for edema), a low pH, promotes granulation tissue formation an produces Inhibine?
Medical grade Honey (forms hydrogen peroxide; e.g. Manuka)
What type of bandage is indicated for a large fresh laceration with profuse serosanguinous exudate?
Dry-to-dry
What type of wound closure is it when the wound that was not closed immediately is amenable to closure within 5 days?
Delayed primary
T/F: Drains should exit through the incision line.
FALSE, they should never exit through the incision line not should they lie directly under the suture line
What do passive drains depends on to move fluid? What else is important?
Gravity and capillary action
The surface area of the drain
Why might a fenestration Penrose drain be less effective?
Reduced surface area
How are Penrose drains secured?
Percutaneous tacking suture
What biological wound dressing takes on the characteristic of the tissue that they are replacing?
Extra-cellular matrix derived (e.g. Porcine small intestinal or urinary bladder submucosa)
T/F: Although they are more efficient, active drains cause more drainage maceration to surrounding skin.
False, reduce that risk.
What is the primary cause of drain failure?
Obstruction
T/F: Fenestrations are beneficial for both active and passive drains.
False, only active drains
Which is most important when placing walking sutures?
Sutures must engage the dermis superficially and the fascia deeply
Usually when you do remove a drain?
3-7 days (drainage will never stop due to foreign body reaction).
What is the difference between a skin graft and a skin flap in terms of blood supply?
In a skin flap blood supply in maintained or reestablished quickly, in a skin graft the blood supply is severed.
Which tissues are included in a skin flap?
Epidermis, dermis, and hypodermus (panniculus muscle when present)
(superficial plexus, middle plexus, and deep/subdermal plexus)
What type of flap would you place if a flap was required on the mandible? How many sides does it have?
Single pedicle advancement flap 3 sides
What do you call the areas of skin of a flap that are removed to prevent dog ear formation?
Bürows triangles
If there is skin available on both sides of the wound what type of flap can be used?
H-Plasty
How much larger than the defect should the arcing incision for a rotation flap be?
2.5 times the width of the defect
Why should a narrow tip be avoided when making a flap?
High potential for vascular compromise to that area
T/F: More than 1 Penrose drain should not be placed to minimize the risk of a foreign body reaction.
False
How can you prevent dog ears from forming when placing a flap?
Space sutures further apart on the side of the flap where a dog ear could potentially form.
T/F: Dog ears should always be removed because they normally do not resolve and thus pose an infection risk.
False, only large ones should be removed.
How can you reduce the risk of compromised vascular supply or excessive tension on the incision when you need to make a flap that covers a large area?
Make multiple flaps.
What is a flap called when the donor skin is in a different axis from the wound?
Transpositional flap
Which vessel is commonly included in an axial flap on the front limb? Hind limb?
Front: Thoracodorsal
Hind: Caudal superficial epigastric
T/F: An flap made on the belly can be made longer in males than in females due to the active mammary tissue.
False, longer in females due to the increased blood supply. The presence of a prepuce in males also limits the length.
If you are concerned about kinking the vessels when making a flap, is it better to make an ipsilateral or a contralateral flap? What is the limitation of the flap you chose?
Contralateral
It can extend a shorter distance
What is the incision called that connects the donor site to the wound when making a flap? What procedure can be done to avoid making this incision?
Bridging incision
Procedure: “Tubing” the flap (requires second surgery to remove tube)
T/F: A skin graft can be used to correct a skin defect on the extremities.
True
What must occur before a skin graft can be placed?
Wound management to allow granulation
What are the 3 components of granulation tissue?
Fibroblasts
Collagen
Blood vessels
How long does granulation tissue usually take to form? What if VAC is used?
5-7 days
VAC can be within 3 days
What is the grafting technique called where small segments of skin placed to speed up epithelialization?
Punch/seed graft
A full thickness skin graft consists of ____ and _____.
Epidermis
Dermis
You are assisting in a surgery and the surgeon is preparing a skin graft. He has drawn an arrow on the pattern he has made for the graft, why?
To note hair growth direction so it is placed in the correct configuration
T/F The cutaneous trunci muscle and superficial SQ tissue must be removed from the graft before applying it.
True, it enhances revascularization of the graft
What is the type of graft called in which parallel rows of staggered slits are made in the graft?
Mesh graft
T/F: When you place a graft on the donor site, it should remain loose and easily movable until sutures are placed.
False, a fibrin seal should form quickly otherwise it could be a bad sign.
What is the type of flap called that incorporates a direct cutaneous artery and vein?
Axial pattern flap
What is a common complication with large flap placement?
Edema, due to messing with the lymphatics
What therapies can be used to manage a compromised flap?
Hyperbaric oxygen and leeches
What is the bipedicle flap called that has bidirectional blood supply and attachment?
Pouch flap
Why must chronic tissue be avulsed prior to attempting a skin graft?
Because chronic granulation tissue contains mostly collagen and few blood vessels
What clays are considered Infection Potentiating Factors?
Montmorillinite
Kaolinite
Illite
What technique is often used to aid in the closure of an antebrachial wound?
Presuturing (Lembert or Halstead type sutures)
What factors affect the development of postoperative wound infections?
Time
Microbial pathogens
Local wound environment
Host defense mechanism
When are therapeutic antibiotics used in surgery?
When an infection is already present
What should you do/use/administer if the risk of infection from surgery is high or if infection would have catastrophic results?
Administer prophylactic antibiotics 30-60 min prior to skin incision, continue peri-op up to 24 hours (not longer)
How is the treatment of burns complicated by inhalation injuries?
Smoke inhalation causes pulmonary edema with vascular congestion, interstitial edema, and atelectasis.
Pneumonia often occurs several days after smoke inhalation.
Name some common etiologies of thermal burns in domestic animals.
Fires, electric heating pads, hair dryers, scalding water, steam, hot cooking oil, exhaust systems, and hot pipes
What are the methods of wound debridement?
Surgical
Autolytic
Chemical/enzymatic
Mechanical
Biosurgical
Application of ______ may prevent progression of partial-thickness burns by reducing edema and improving circulation.
Negative pressure wound therapy/VAC
How are skin graft managed post-op? When is the bandage changed and how long should it remain bandaged?
Apply antibiotic ointment and non-adherent dressing
Absorbent secondary layer
Splint or cast over joint
Change dressing in 24-48 hrs and continue for at least 10 days
