Wound management Flashcards
Classify the difference between an open and closed traumatic wound.
Open wounds have penetrated body tissue. Closed are non-penetrating
What are the four types of operative wounds? Describe them.
Clean (surgically created)
Clean-contaminated (surgically created with opened viscera)
Contaminated (wound with opened/hollow viscus=traumatic)
Dirty (pus contained, perforated hollow viscera)
How much time is needed to pass before the risk of infection in a surgical wound is doubled?
70-90 minutes. (every hour)
What is the most common source of operative infections?
Patient’s endogenous flora. (skin, GI tract)
T/F: a patient with a surgical implant may show infection at that site even after 1 year post-op.
True
Define prophylactic antibiotic use
Administration of the drug prior to wound contamination
Define therapeutic antibiotic use
Administration of the drug as mean to fight an already present infection
What are two good prophylactic drugs to give pre-operatively? (IV)
Cefazolin and Cefoxitin (more for GI/colon obstruction)
When would you use intraoperative antibiotics?
When there is an unexpected contamination of the surgery site or the surgery is taking longer than expected.
Which animal’s integument heals faster, dogs or cats?
Dogs.
What is a good diagnostic test to consider doing before surgically approaching a wounded animal?
X-rays, ultrasound. Diagnostic imaging.
Is a Penrose drain active or passive?
Passive.
What is a good suture material to use on wounds that will require long lasting tensile strength and hold?
PDS. (can last months)
What other injuries may be combined with degloving injuries?
Crushed/broken bones. (heal skin before orthopedic intervention)
Physiologic vs Anatomic degloving. Which one still has the skin in tact?
Physiologic.
What is the status of the tissue if it has become black or white?
Dead, necrotic tissue.
Define neuropraxia.
Damage to the organ to the point where nerve synapses are temporarily interfered and lack impulse.
What are the two types of burns that define the level of severity in a burned patient?
Partial thickness and full thickness burns. These describe the depth of the burn.
What is another organ system to think about when a dog’s integument system has been burned from a fire?
Respiratory system. (smoke inhalation)
List some ways to manage initial burn patients (four listed)
Cool the injured issue, topical treatment, analgesics, fluids
What are the effects of topical treatment for burn patients? (aloe vera, silver sulfadiazine)
To delay the development of infection under the dead tissue (eschar)
What are some ways to treat burn wounds?
Wound debridement, hydrotherapy, negative pressure wound therapy, wound closure, wound lavage
What part/s of the body have enough skin to close a large open wound?
Above the elbow/knee, back/torso/body
T/F: Burns
True
List some possible reasons as to why an animal’s wounds may not heal, despite appropriate treatment.
Presence of a foreign body, immunodeficiency, pathogens/disease, concurrent disease, nutritional status, drugs
T/F: Carbon material objects like gravel, pellets, glass, and steel typically cause dramatic infection.
False. (organic, porous materials are poorly tolerated and must be removed)
Case: an animal comes with a swollen lesion and is given antibiotics and other meds. Throughout the treatment, the lesion had slowly diminished, but once the patient finished the medications, the lesion swelled back up. What is a potential cause of the lesion?
Foreign body.
What is the difference between a sinus and a fistula?
A fistula is lined by epithelium. Sinuses have communication between the mesothelial layer and the skin. Sinuses typically from foreign bodies.
What is the best intraoperative diagnostic imaging tool?
Ultrasound.
What is an example of a dye a surgeon can use to follow a foreign object’s tract/location?
Methylene blue.
Name 3 sources in which a wound can be contaminated.
Endogenous flora (most common), accident site, hospital
When discussing timing of an injury, define the ‘golden period’.
The amount of time from the incidence of injury to when the bacteria have replicated enough in the injury site to cause disease. (usually 6-8 hours)
What are infection potentiating factors (IPFs) and why are they important?
Negatively charged particles that have a large surface area. They bind to positively charged antibiotics, and inhibit phagocytosis and killing of bacteria. Lowers the threshold number of bacteria needed o cause disease (Ex: clay, organic soil)
List a few precautionary methods used when evaluating a wound.
Aseptic as possible, clip/prep surrounding skin and hairs, temporarily closing or packing the wound (use of sterile gauze or jelly)
T/F: Up to 90% of bacteria can be removed by using a lavage on a wound.
True.
What are typical solutions used for lavage?
Saline or balanced electrolyte solutions. Tap water also works.
What is an adequate level of fluid pressure from a syringe for an effective lavage?
7-8 psi.
T/F: It is advised to use antiseptic solutions as lavage once granulation tissue has formed.
False.
List a few antiseptic solutions.
Povidine-Iodine, Chlorhexidine, diluted bleach
T/F: antiseptic solutions are ALL cytotoxic.
True.
Which has a longer residual activity, providone-iodine or chlorhexidine?
Chlorhexidine (12 hours) vs Providone-iodine (4-6 hours)
What are some disadvantage of providone-iodine?
Shorter residual time, formation of inactive complexes with organic matter, potential toxicity.
What are the advantages of chlorhexidine?
Less activity with organic matter, long residual times, and limited side-effects
How long can you keep chlorhexidine diluted in a polyionic solution on the shelf before its precipitates limit its antibacterial activity?
Two weeks.
Define debridement.
Removal of devitalized tissue and foreign bodies.
List the five methods of debridement.
Surgical, autolytic, chemical, mechanical, biosurgical (maggots)
What are the two methods of surgical debridement and which is the more common form?
Layered (more common) and en bloc.
Describe an ‘en bloc’ debridement.
Packing of a wound (with gauze) and dissection of created mass, creating a clean wound.
Describe a layered debridement.
Removal of tissue layer-by-layer starting from the skin to the subcutaneous and then to the muscle.
What is the compound used for chemical debridement and what does it contain?
Granulex. It contains tripsin (debriding agent), castor oil (decreases desiccation), and balsam of Peru (capillary formation)
Which of the the debridement methods is commonly used but is not the most friendly to the tissue integrity?
Mechanical debridement.
What indications would lead to the use of mechanical debridement?
Wounds in lag phase with heavy contamination or thick viscous exudate.
When would you want to leave the wound open? (several reasons)
Can’t fully clean area, foreign body, concerning level of infection, exudate levels, edema/swelling
When is the best time to use negative pressure wound therapy?
When the wounds are in late lag phase or early proliferative phase in healing
What are some benefits to Vacuum-Assisted Closure?
increased tissue blood flow, decreased edema, less bacterial burden, accelerated granulation tissue formation, less frequent bandage changing
Define cortical fenestration.
When holes are placed in the bone of skin injuries (especially distal limbs) to provide more blood flow and healing to that site.
What is one of the biggest key cells that have a role in healing?
Macrophages. They decontaminate the injury site and also send signals to surrounding tissue to direct healing.
What are some substances you would want to use when dealing with a wound containing moderate/high levels of exudate?
Calcium alginate, honey (unpasteurized), sugar
What beneficial effects does honey have on wounds?
Cleans it, promotes granulation tissue formation, antibacterial/antifungal
What would you use to help with a gunshot wound? (it’s a powder)
Maltodextrin.
Name the indications for using a wet-to-dry adherent dressing.
If there is necrotic tissue, foreign bodies, and/or high viscosity exudate is present.
What is one way to release an adhered bandage away from the wound with limited stress on the patient?
Rehydrate the dressing.
Name the indications for using a dry-to-dry adherent dressing.
Degloving injuries, bite wounds, lacerations, deep cavity wounds.
How does a wet-to-dry bandage work?
By placing a wet bandage onto the wound, the fluids and dead tissue will adhere to the liquid from the gauze and removal of that dressing will bring the contaminants along with it.
What is a good dry-to-dry bandage to use an how does a dry-to-dry bandage work?
Kerlix A.M.D, has antimicrobial function, also the dry bandage will adhere to contaminants and cause debridement.
What is/are the disadvantages of adherent dressings?
Bacteria flourish in wet environments, and also may travel through the bandage.
When would you use a porous non/low-adherent dressing?
When you are protecting sutured wounds or the wounds have a healthy layer of granulation tissue.
What are the advantages of nonadherent dressings?
They keep the wound moist, allow excess fluid to drain, and do not damage any new tissue when bandage is being changed.
What is a nonadherent dressings that is used?
TEFLA sterile pads
When would you use a moisture retentive dressing over an adherent dressing?
When the wounds are in late debridement. This optimizes the body’s healing abilities.
T/F: In order to use a moisture retentive dressing, the wound MUST be healthy and have limited exudate.
True!
T/F: Moisture retentive dressings have high MVTR (moisture vapor transmission rates)
False.
Name a few biological dressings.
Equine amnion
Xeno/allografts
Collagen, PSIS, PUBS
How does porcine small intestinal submucosa (PSIS) work?
It reinforces wound tissue and is absorbed by the body and replaced by host tissue. (it’s collagen)
What are the indications for using SIS?
Degloving injuries, wound repair guidance (inhibits wound contraction which leads to more epithelialization)
What are the four types of wound closures?
Primary closure
Delayed primary closure
Secondary closure
Second intention healing (contraction and epithelialization)
Define Primary closure of a wound.
The immediate closure of the wound. Clean/clean-contaminated wounds. Healthy.
Define delayed primary closure of a wound.
Wound is left open for 2-5 days to allow for repeated lavage and debridement. Wait until clean-contaminated status til closure.
Define secondary closure.
Wound is closed after granulation tissue covers the wound.
What are the two types of secondary wound closure?
Deep narrow and wide.
How would you do a secondary closure over a deep narrow wound?
Let granulation tissue form over the wound, then simply close the site over it.
How would you do a secondary closure over a wide wound?
Let granulation tissue form over the wound, then mobilize the skin edges and advance them over the granulation tissue. (undermining)
What are the differences between contraction & epithelialization, spontaneous recovery, and second intention healing?
They’re the same when it comes to wound closures!
What is the cut off mark (%) of the circumference of a wound on the distal limb where it ‘should’ heal well under secondary intention healing?
25%
If over 50% of the circumference of a wound at the distal limb is present, should you consider using contraction and epithelialization as a means of wound closure?
Probably not, you may want to surgically reconstruct the site.
In what scenarios may secondary intention healing stop?
When the wound has healed, when tension on the skin exceeds the pull of the myofibroblasts, or when the collagen in the wound interferes with the pull of the myofibroblasts
T/F: Circular wounds have bad healing effects.
True.
Define a wound contracture.
When a wound is healed through secondary intention, but leads to the interference of another organ’s function.
(ex: burn patient healed, but scar tissue formed between stifle and abdomen, disabling ability to move leg. easily fixed - remove the connecting tissue)
Skin tensions lines are typically stronger from dorsal/ventral, or cranial/caudal?
Dorsal/ventral.
If you are to make an incision along the lateral side of a body wall, would you to place the suture line (not suture bites!) dorsal/ventral or cranial/caudal?
Dorsal/ventral.
T/F: you want to make your incision line ALONG the skin tension line.
True. That way the sutures will have limited tension when place.
What suture method can you use when you have a 3-way lesion to close up?
Take an intradermal bite of the flap among the 3-way junction of those tissues.
Define primary contraction of tissue.
Is the immediate retraction of the skin edges once they are cut.
What are some characteristics that affect the ability to undermine an animal’s skin?
The species (difference in blood supply) and the breed (ex: bulldog vs. greyhound)
T/F: When undermining skin, a blunt dissection is used to separate the subcutaneous tissues from the muscle.
True. This preserves direct blood vessels, and has less risk of a hematoma.
What is the purpose of performing walking sutures?
To create a better distribution of tension along the surface of the skin that is to cover the wound. Also to decrease dead space.
What kind of suture material do you use for the walking suture technique, and what two tissues MUST be engaged for this to have a good hold?
Use monofilament absorbable sutures, and engage the dermis and the fascia for good tissue holding.
T/F: Dimples on the skin are a sign that walking sutures were placed poorly and incorrectly.
False!
List some techniques used to enhance local movement of skin (particularly in distal limbs).
Skin stretching (expanders, presuturing)
Releasing incisions (punctate incisions, adjustable mattress sutures)
T/F: Avoid suture lines directly on areas of flexion (ex: hock)
True. Try to make the incision/suture line to the lateral/medial side.
How long is it necessary to keep the presutures for adequate skin stretching?
24 hours.
Describe the steps in performing a multiple punctate relaxing incision.
- ) undermine the skin
- ) place intradermal suture pattern
- ) make rows of staggered incisions on the skin around the sutured incision, while keeping tension on the suture, until it is comfortably closed.
T/F: Multiple punctate relaxing incision patterns work best with an established granulation tissue.
False. Adjustable Horizontal Mattress patterns do!
What tools do you need to perform a multiple punctate relaxing incision pattern?
Monofilament suture, button/s, split-shot (to clamp on the suture and hold it in place)
What is the suture pattern to use when performing a multiple punctate relaxing incision closure?
Continuous intradermal suture pattern.
Name the 3 indications for using a surgical drain.
- ) when the dead space cannot be removed
- ) there is a high chance of fluid accumulation
- ) infection is present
What is the greatest disadvantage of a surgical drain placement?
Increased risk of secondary infection.
What are 3 ways to work against dead space in a lesion?
Suture placements, drains, and compression bandages
T/F: Drains should NEVER exit through the incision line.
True.
T/F: Drains should be placed directly under the suture line.
False. This increases the risk of dehiscence (rupture of a wound under its incision line)
T/F: Tacking a drain with a buried suture is preferred.
False. Percutaneous sutures are preferred.
T/F: The proximal ends of the drain in deeper wounds still need to be sutured in.
False. The tissues will close in on it and hold it in position.
What are the two types of drain methods and how do they work?
Passive - uses gravity and capillary action to move fluid. Depends on the surface area of the drain.
Active - uses a suction device to pull fluid from the wound.
How many exit sites are preferred in an passive drain placement?
One. Two is only preferred when both exits promote draining
How does a penrose drain work?
It’s soft shape conforms well to the wound, and it’s surface area allows the fluid to adhere and drain OUTSIDE of the draining tube.
How do you effectively remove a penrose drain with a double exit?
Prep and clean one end, hold that end, remove the suture, pull the tube out to excise the part of the tube that was inside the wound, then pull the tube out from the other end.
What are the benefits of using an active drain?
More efficient, less risk of the drainage to worsen the surrounding skin, less risk of infection, exit site of the drain can be placed anywhere convenient
What is a biggest cause of active drain failure?
Obstruction.
What is the importance of an ingress/egress system?
Using separate tubes where one is strictly for fluid to enter the body, and another is for fluids to exit. NEVER inject into a egress drain
When should you remove a drain?
Usually 3-7 days. Also when the drainage has decreased, or when the discharge becomes serous or serosanguineous (culture/cytology)
What is the main difference between a skin flap and a skin graft?
The blood vessels in a skin flap are in tact. Skin grafts but have their blood supply severed and grow new ones once placed.
What are the three types of blood supplies for a skin flap?
Subdermal plexus (SQ included),
Axial pattern flap.
Revascularized
For flaps that cannot rotate on a pivot point, what are two alternative methods?
Pedicle advancement flap, H-plasty
What anatomical structure most commonly uses the single pedicle advancement flap?
Eye
What are Burows triangles?
the flap of skin removed to prevent ‘dog ears’ from forming when the flap is advanced.
T/F: H-plasties have less of a risk of vascular compromise than single pedicle advancement flaps.
True
With rotation flaps. how many times the width of the defect do you want to make the first arcing incision?
2.5 times
With rotation flaps, what do you do if there is tension from the flap?
Continue the rotational incision until tension is relieved.
Where is a location where a DOUBLE pedicle advancement flap would be used?
The back dorsal end of the tail and lower back
What is a transposition flap?
A three-sided flap where the skin is incised 60-90 degrees from the wound and rotated into the surgery site.
Where are some locations in which you would perform a transposition flap?
Top of the head (donor skin from neck) proximal brachial area (skin from thoracic region),
What is the difference between the axial pattern flap and the subdermal pattern flap?
With the axial pattern flap, we know where the direct cutaneous artery and vein are, and thus are able to make a larger flap.
Where are the most commonly used blood vessels with axial pattern flaps?
Thoracodorsal, caudal superficial epigastric
What are some potential complications with flap placements?
Flap edema, seroma, infection, partial dehiscence, vessel thrombosis
How can you manage a compromised flap?
Assess its blood vessels, hyperbaric oxygen drives oxygen to the area of interest, LEECHES!
What are distant flaps, and what body part are they usually for?
Flaps that are still connected to the body that are made for a lesion farther away. Ex: taking skin from the torso and applying it to the forearm.
Which flap technique must the patient remain in a fixed position while bandaged for at least two weeks?
Distant, pouch flaps.
What are the indications for placing a skin graft?
Skin defects on extremities, big burn wounds, reconstructive procedures
Differentiate between full and split/partial-thickness skin grafts. (and burns)
A full thickness graft contains all layers of the dermis and epidermis. A split-thickness graft only uses a fraction of the dermis.
What are the three most factors when dealing with skin grafts?
where to put them, how to put them, and post management
What must happen for a graft to ‘take’?
New blood vessels must grow into it
How does cortical fenestration work?
Holes in the exposed bone lead to blood clots which create a matrix for granulation tissue to form
What are the signs for granulation tissue that is ready for grafting?
Pink and glistening
Smooth surface
Wound contraction and epithelial migration
What are the three different types of skin grafting techniques?
Sheet, punch, strip
T/F: Full-thickness skin grafts also contains the hair follicles and the adnexal structures
True.
Which skin graft, full or partial, has the best cosmetic appearance and function, and is the most commonly used graft in small animals?
Full-thickness
How do you prepare the recipient bed?
Scrape the bed with a scalpel blade to remove debris and expose capillaries. Cover with chlorohex gauze while preparing graft
What is the easiest method of dissecting a skin graft?
Remove the entire tissue area, deep to the muscle, then remove the subcutaneous tissue after
What is important about graft preparation?
It enhances the revascularization of the graft
What are the advantages of a mesh graft?
Allows for the expansion of the graft for more surface area, drains blood from under the graft, and better shape conformation for uneven surfaces
What is a requirement that the recipient bed must have in order to perform a punch graft?
Well developed granulation tissue
Where is a possible site where one would perform a punch graft?
At the digits
How do you postoperatively care for a skin graft?
Antibiotic ointment, dressing, splint/cast (over joints), change every 1-2 days
T/F: You must use adherent dressing for skin graft surgeries.
False. Nonadherent
Why is it common to see bruising from a healing skin graft?
It shows the high arterial flow and some venous congestion
T/F: If you look at a skin graft 5 days after its surgery and there is white necrotic tissue, the surgery has definitely failed.
False. Give it more time!
T/F: The thinner the skin, the longer it takes for a skin graft to revascularize
False. Thicker
What does KISS stand for?
Keep is simple, surgeon (stupid)
