Large Animal Sx - Integument 2

drraythe's version from 2015-11-24 20:14

Skin grafting 2

Question Answer
CQ: (T/F) excessive granulation tissue Is a common complication of upper body woundsfalse- LOWER
CQ: (T/F) excessive granulation tissue Is usually a greater problem in wounds that are bandaged as compared to those that are managed without a bandageF- oppposite
CQ: (T/F) excessive granulation tissue Can usually be adequately managed by daily cleaning of the wound by spraying it with water.False- Rather, Is sometimes removed by using a caustic chemical, such as copper sulfate (or you cut some off)
cosmetic down-side to punch grafts?you can never seem to get the hair line up perfectly, so odd patches of hair on horse
what tool will you need to cut a partial-thickness segment of skin for a graft?dermatome- either handheld (difficult to use) or electric/pneumatic (expensive)
most commonly used donor site for a split thickness graft?Ventral abdomen is most commonly used bc Requires a relatively large flat skin surface for the dermatome (harvevsting instrument) to work
what is the possible results of using a very thin partial thickness graft?take better, but Result in a less aesthetic appearance, as well as Result in epithelium that has less strength
technique for applying a split-thickness graft?use dermatome to harvest skin from ventral abdomen, choosing thickness you want. Grafts are applied and either sutured or glued to the wound edges or sutured to the granulation tissue. Then apply Pressure bandages are applied over nonstick pads (Splints or casts may be indicated to prevent motion). Graft sites are bandaged and carefully managed for two weeks
are Mesh grafts full or partial thickness?could be either!!
what is the technique for a mesh graft? what are the benefits of it being a mesh?Full or split thickness grafts that are modified either in a special appliance (a jig) or free hand by cutting numerous small slits in them. This Allows for expansion so that a smaller amount of skin can be used to cover a defect, as well as Prevents serum accumulation under the graft. (Applied in essentially the same manner as a split thickness graft- ie either sutured or glued to the wound edges or sutured to the granulation tissue) (image is of a jig which turns donor tissue to mesh)
Tunnel and strip grafts- what unique benefit do these grafts have?This technique allows grafting of areas in which there is considerable motion
technique for Tunnel and strip grafts?(modifications of the split thickness graft). Inject saline under the skin with LA to then remove Long split thickness segments. These are applied to adhesive tape (the sticky side of the tape is applied to the hair side of the graft). The tape is trimmed to the same width as the graft. The graft and tape unit are attached to a long straight needle which is threaded just under the surface of the granulation tissue (Care must be taken to position the tape towards the surface of the granulation tissue!). The wound is bandaged. One week later the granulation tissue over the tape is cut and the tape is very carefully removed leaving the graft in place
what are some ways you can modify the tunnel and strip grafts?By using long alligator forceps to produce the granulation tissue tunnel, By not using the adhesive tape and just pulling the graft through the tunnel with the alligator forceps (It is more difficult to get the hair side of the graft positioned toward the surface of the granulation tissue with this method).
when is pre-suturing usually done?A technique that can be used to close a defect or more commonly to remove a blemish
how do you perform the pre-suturing technique?Stay sutures are placed to markedly stretch the skin for two or three hours (in class he said 6-8 hours, even overnight) prior to closure. This technique minimizes the tension applied to the skin edge at the time of closure and allows for removal of a larger defect or closure of a larger wound

Complications of wound healing- joint injuries

Question Answer
what difference is there in if the joint capsule is intact or involved?If the joint capsule is intact the healing is only slightly more complicated than any other wound. When the joint capsule has been penetrated the situation is critica
with joint wounds, what will inc the healing time?Increase in motion usually results in some increase in healing time (takes longer to heal!)
how can you dx/confirm if there is an open joint in the wound?(1) find Synovial fluid in the wound (2) Flushing through the joint-- Surgically prepare a joint injection site remote from the wound, Insert a needle into the joint and infuse sterile saline under pressure. If fluid flows from the wound the joint is obviously involved
If you find a wound close to a joint, what should you assume?Assume Jt. Infected Until Proven Otherwise
If you suspect an injected joint, you take a culture, and it comes back negative, what do you know?A negative culture doesn't mean the joint is not infected
why might a synovial fluid culture come back negative even if it is infected?Synovial fluid represses bacterial growth, so Bacteria might be present in the synovial membrane but not in the joint fluid
what is a way to increase your chances of a positive culture from an infected sample of synovial fluid?Blood Culture Medium Enrichment is Three times more effective culturing bacteria from a sample than other methods
if you get a positive culture result from synovial fluid, what should you think/do?A positive culture proves infection and allows for sensitivity testing to determine the appropriate antibiotic to use
how many WBC/microliter of synovial fluid means the joint is prolly NOT infected?<10,000 WBC/uL
how many WBC/microliter of synovial fluid means the joint is prolly IS infected?>50,000 WBC/uL
how many NEUTROPHILS would you see to consider a joint as infected?>90% neutrophils
if you want to tx infected joint, how much abx do you give intra-synovially and how much do you give parenterally?Dosage 1/3 in joint remainder parenterally
how do you manage an open joint wound where it is <8 hrs old with minimal tissue loss?flush, debride, antibiotics & Close
how do you manage an open joint wound where it is >8 hrs old with minimal tissue loss?Delayed Primary Closure
if there is a joitn wound with Inadequate Tissue to Close, what should you do?Maintain Under Sterile Bandage. Until Granulation Tissue Closes
when is an infected joint painful, and when isn't it painful?Open, Infected –Not Painful. Closed Infected –Very Painful

Complications of wound healing- exuberant granulation tissue (EGT)

Question Answer
exuberant granulation tissue's common name?proud flesh
CQ: (T/F) EGT is a greater problem in upper as compared to lower leg woundsF- it is more of a problem in lower leg wounds
CQ: (T/F) Topical corticosteroids are used to control EGT's developmentT
CQ: what chemical can be used to help get rid of EGT? Copper sulfate
when can't you use copper sulfate when there is EGT?If there is bone exposed- damaging to bone
what are 3 predisposing factors to proud flesh?Minimal muscle mass, Limited excess skin, Continual irritation - tall grass, chronic infection, motion (this is why lower limbs are so prone)
what is the reason the granulation of proud flesh is such a chronic problem?When granulation tissue proliferates above the skin edge. It interferes with epithelialization and wound contraction
how do you sx manage EGT?Sedation + - regional anesthesia (there are no nerve endings in excessive granulation tissue)--> Esmarch bandage --> Scalpel to remove tissue to slightly lower than the skin edge--> Pressure bandage to control hemorrhage
what is an esmarch bandage?thin rubber bandage- start at distal limb and wind it up proximally, this dispels blood from the area you want to work on in order to minimize hemorrhage.
what are 4 examples of caustics which you can use to control EGT?Podophyllin in compound tincture of benzoin, Copper sulfate powder (5 to 100% concentration), Antimony chloride (be careful it is very potent), Hydrochloric acid and sulfur (be careful it is very potent)------- *With antimony chloride and HCl. It is very important to prevent the animal from chewing through the bandage and getting the caustic in its mouth or eyes
explain the technique for application of severe caustics to tx proud flesh?clip area, Apply petrolatum liberally to normal tissue. Apply caustic to granulation tissue. Then Cover with petrolatum impregnated gauze. Apply pressure bandage. Re-bandage with caustic every other day (Varying amounts of tissue will slough with each bandage change)
what are 4 things you can do to control development of excessive granulation tissue?(1) Minimize irritation and motion (2) Corticosteroid containing ointments (3) Mild caustic agents (4) Enzyme preparations (meat tenderizer is commonly used)
what can you do to Minimize irritation and motion to help prevent development of proud flesh?Pressure bandage over a nonstick pad, Splints and casts
CQ: (T/F) pythiosis causes intense puritisT
CQ: (T/F) pythiosis occurs all over the worldF
what does "phycomycosis" refer to? a general term to include both pythiosis and conidiobolomycosis
Pythiosis can be caused by what organism(s)?Pythiuminsidiosum or Hyphomyces destruens
pythiosis common names?leeches, swamp cancer
which problem causes marked puritis?pythiosis
Conidiobolomycosis is caused by what organism(s)?Conidioboluscoronatus, Entomophthora coronata
Phycomycosis (Pythiosis+Conidiobolomycosis) usually occurs where?In the United States, almost exclusively within 250 miles of the Gulf Coast
where in the body does pythiosis like to live?Usually involves the lower extremities. Horses spending time in ponds sometimes have involvement of the upper limbs or mammary gland
where in the body does Conidiobolomycosis like to live?Occurs almost exclusively in the nasal passages
what are the clinical signs of pythiosis?Infection is extremely invasive, lesions are extremely granulomatous with rough textured grey to yellow exudate (reason for the name "leeches"). There is a marked pruritis associated with infection. The infection causes the production of excessive granulation tissue
what are the clinical signs of Conidiobolomycosis?Single or multiple usually ulcerated nodules and granulomas in the nasal passages. Significant thickening of the nasal septum, and chronic Bloody nasal discharge with abnormal resp signs
if you need to send in a sample of a phycomycosis for histopath and culture, what SHOULDN'T you do?Don't send specimens for culture on ice--> Minimal cold kills the organism
if there is a an intensely pruritic granulating lesion, what should you do?need RAPID ACTION! To delay treatment for several days or weeks might make the difference between success or euthanasia
what kinda environment does phycomycoses like to be in?Semitropical to Tropical, Stagnant Water
Immunotherapy is effective for phycomycosis in what situations?Immunotherapy is relatively effective (approximately 75% cure rate) in the treatment of pythiosis, but ineffective in the treatment of conidiobolomycosis
what should you know about the vaccine for phycomycosis?The suggested routine is to use the vaccine to reduce the size and extent of the lesion and then to surgically remove the smaller lesion (so it is used more for tx than prevention. Vaccine is given subcutaneously once a week for 3 weeks
what route of delivery is used for the phycomycosis vaccine?it is SQ! there will be Injection site problems if given intradermal
So, an animal has phycomycosis and then you give it the vaccine....what happens? (timeline?)Reduced inflammation in 3-7 days--> 7 to 10 days sloughing of involved tissue (so give in brisket area or somewhere where it can support sloughing)-->14 days healing
in WHO is the phycomycosis vx more effective?90% success –equine. 53% succes-canine
can you sx fix phycomycosis?Effective if all the infected tissue can be removed
what is Phycofixer?tx you can use to tx phycomycosis. It is Ketoconazol dissolved in .2 normal HCL, Rifampin, DMSO
which antifungal can be used to tx phycomycosis, and what is the downside to this?Amphotericin B can be used, but Parenteral treatment is extremely expensive
what is the recc tx regimen for Conidiobolomycosis? cautions?you can give Iodides (10 G/day), but need to stop if animal develops a fever or their haircoat becomes scruffy
(long notes) if you are tx with parenteral amphotericin B, how should you know if you need to stop tx?Discontinue or reduce the dose when BUN >40 or the horse becomes severely depressed or anorectic
what are the two topical tx for phycomycosis?Amphotericin B (inject into lesion), Phycofixer (Best applied by soaking a bandage and keeping it wet)
when do you use idodine as a tx? how do you use it?use for tx of Conidiobolomycosis. Can give IV or orally.
what are the two forms in which you can give iodine as therapy, and how does administration differ between them?If giving NaI, can give orally or IV. but if giving KI, CAN ONLY DO ORALLY NOT IV
caution you should be aware of as a vet tx phycomycosis?humans can occasionally be infected (If the infection involves arteries the routine treatment is amputation !!!!)
CQ: (T/F) Wounds involving the coronary band routinely heal quite well if just kept cleanF
CQ: (T/F) Wounds that involve exposed bone should be bandaged to protect the boneT
CQ: (T/F) Small foreign bodies in a wound usually do not slow down the healing processF
CQ: (T/F) In cutaneous habronemiasis the adult habronema parasite is present in the skin lesionF