Wound Healing & Management
What happens during the proliferative phase?
- fibroblasts & endothelial cells enter wound to form extracellular matrix - new blood vessels are formed to nourish new tissue - formation of granulation tissue
What supplies doe we need for wound lavage?
- isotonic crystalloid solution - 18/19 g needle & large syringe - sterile bulb syringe & bowl
Why do we lavage wounds?
- remove foreign debris - remove necrotic tissue - decrease microorganisms
What are some examples of wound characteristics?
- surgical implantants - drains - suture - collar - extraneous material - location
What factors determine the method of healing and closure?
- time since injury - degree of contamination - amt. of tissue damage - thoroughness of debridement - blood supply to wound - patient's health - closure w/o tension/dead space - location of wound
What happens during the maturation phase?
- wounds gain the most strength - collagen realigns along tension lines
What are the 4 levels of wound classification?
1. Clean 2. Clean-Contaminated 3. Contaminated 4. Dirty/Infected
"Dirty/Infected" wounds consist of...?
1. Perforated viscera 2. old traumatic wounds 3. high bacterial counts (>10^5 organisms/g of tissue)
What are all the different types of debridement?
1. Surgical 2. En Bloc Excision 3. Enzymatic 4. Mechanical 5. Biological
What are the 3 wound healing phases?
1. inflammatory, 2. proliferative, 3. maturation
How long does the proliferative phase typically last?
2-3 weeks
Which burn severity may form blisters and will be healed through 2nd intention?
2nd degree
How are abrasions typically left to heal?
2nd intention
How long after the insult does the inflammatory phase typically last?
3-5 days
Which burn severity must be debrided and may require skin grafts?
3rd degree
Which burn severity may require surgical reconstruction?
4th degree
A Jackson-Pratt drain is an example of which kind of drain: active or passive?
Active (creates a vacuum in which fluid is sucked out & into an external container)
Which of the following is not an example of a "Clean-Contaminated" wound? A) Colon surgery B) Cystocentesis C) Rectal Surgery D) Gastric Surgery E) All of the above were examples of "clean-contaminated".
C) Rectal Surgery (This is classified as "contaminated". "Clean-contaminated" contains: 1. Surgical wounds w/ minor breaks in aseptic technique 2. insults occurring under aseptic conditions but a hollow organ is entered 3. a traumatic wound w/ minimal contamination, <6-8 hrs old)
T/F: If a contaminated tissue becomes infected, healing can continue because the body already has launched an immune response.
False (Infection will always stop the repair phase of healing)
T/F: Third intention healing is when we first allow a wound to form granulation tissue then we undergo tertiary closure to suture it.
False (It's secondary closure.)
T/F: Wound contraction caused by myofibroblasts to reduce wound size will start about 4-6 days after the injury.
False (It's usually not until 1 week after the injury that wound contraction occurs)
T/F: Wounds that are created purposefully do not immediately begin the process of wound healing.
False (Whether incidental or purposeful, the wound healing process begins immediately after the insult to the tissue integrity).
T/F: Blood flow to the injury site is not encouraged because of the risk of hemorrhage in the lag phase.
False (Without proper blood flow to the site of injury, infection can occur because no leukocytes will be able to arrive)
T/F: Dehiscence can only happen during the inflammatory phase.
False (unintentional reopening of wounds usually happen during inflammatory phase, but they can happen in the proliferative phase)
What is the definition of "secondary intention"?
Healing of a wound by granulation tissue formation, epithelialization & contraction; NO SUTURING BY VET
A penrose drain is an example of which kind of drain: active or passive?
Passive (allows fluid to exit the wound via gravity)
If a patient presents with a severe wound but is in shock, cardiac or respiratory distress, what should you do first?
cover wound with a moist, sterile bandage to prevent contamination, further injury while stabilizing patient
How does radiation impact wound healing?
it damages and affects rapidly growing cells and affects cellular division
What is most important in wound lavage when it comes to removing debris without destroying healthy tissue?
lavage pressure
What components make up wound exudate?
leukocytes, fluid from vessels and lymph
Where are degloving injuries most common?
limbs & tails
What does the granulation tissue consist of?
myofibroblasts, endothelial cells, inflammatory cells, new blood vessels, extracellular matrix
What's another name for "decubitus ulcers"?
pressure sore
Which type of wound is most likely to have a drain placed?
puncture wounds
What is the purpose of debridement?
remove any contaminated or necrotic tissue from a wound
About when does the maturation phase typically start?
~3 weeks after the injury
Y/N: Are the following burn classifications accurate? 1st degree: only the epidermis is affected 2nd degree: partially thickened dermal wound 3rd degree: entire dermis is damaged 4th degree: deeper anatomy is injured
Yes
What is a laceration?
a deep cut or tear in skin or flesh.
What defines an abrasion?
a partial thickening of the dermis
When would you want to perform biological debridement?
chronic wounds with poor tissue perfusion
Why is it important not to use too tight of a bandage?
Tight bandages can compromise the wound's blood supply which will in turn restrict O2 and nutrients needed for healing
T/F: A non-traumatic, non-infected surgical wound is an example of a "Clean" wound.
True (Clean wounds are insults that occur under aseptic conditions)
T/F: Primary intention means that we heal a wound using primary closure - suturing a fresh clean wound close.
True (Generally surgical wounds w/o granulation tissue; Delayed Primary Closures can also be used. A contaminated wound is treated openly for 2-3 days then closed via primary closure)
T/F: 3-5 days after the injury is when epithelialization starts.
True (Right about when the inflammatory phase ends is when epithelial cells will start replacing scabs)
T/F: We want to encourage some swelling and fever because it is part of the body's natural healing process.
True (Some is good. A lot, however, is not as beneficial)
T/F: Surgical debridement is best for large wounds whereas En Bloc Excision is best for mass removals.
True (Surgical is under general anesthesia and also works well for wounds w/ sig. trauma; En Bloc Excision is when the wound is removed and the fresh edges are then closed surgically so it's better for smaller wounds)
T/F: The effectiveness of the bandage can determine how well the wound ultimately heals.
True (The bandage can affect blood supply to the wound and the amount of movement allowed)
T/F: Wound Healing means "what the body does" whereas Wound Closure means "what the vet does".
True (Those are the definitions; the body "intends" to heal itself and the vet gets in the way by "closing" wounds)
T/F: The type of surgical instrument used to create the wound can affect how the wound heals.
True (a scalpel blade will make a sharp surgical incision but an electroscalpel will cause electrocoagulation)
T/F: Fibroblasts deposit collagen during the proliferative phase, thereby allowing the wound to strengthen.
True (collagen is serving as "replacement skin" as the body continues to repair this wound)
T/F: Bite wounds are examples of puncture wounds.
True (puncture wounds are classified as wounds with small openings but with deep tissue damage. Other examples include: bullets, arrows, impalement)
T/F: A moist healing environment is preferred over a dry one.
True (the more moist the environment, the easier the healing process will be)
About how long after the insult does the proliferative phase start?
Typically begins 2-3 days afterwards
What are some examples of host factors?
- age - disease - nutritional status - medications - treatments
What all happens during the inflammatory phase?
- blood fills the wound to clean the wound surface - blood vessels at wound site constrict to slow down any hemorrhaging - platelets form clots to help stabilize wound edge - wound fills w/ macrophages & neutrophils - release of growth factors
What enzyme is used for enzymatic debridement?
Collagenase
Which of the following is an example of a "Contaminated" wound? A) Bite wound B) Perforated colon in surgery C) Abscess D) All of the above E) None of the above
D) All of the above ("Contaminated" wounds consist of: 1. surgical wound w/ a major break in sterile technique 2. surgical entry into a contaminated area 3. traumatic open wound, >6-8 hrs old)
Which of the following is false: Once the patient is stable... A) We can consider sedatives or analgesics for pain. B) Wear gloves any time we are attending to the wound. C) Clip fur around the wound edges. D) Clean with a diluted antiseptic scrub.
D) Clean with a diluted antiseptic scrub. (Scrubs and alcohol are not recommended in this situation. What we want to use is a diluted antiseptic solution of either chlorhexidine or iodine)
Which stage of healing is known as the "lag phase" because the wound is the weakest at this point?
Inflammatory phase
What may be applied to the wound to keep it moist?
Sterile lube or sterile 0.9% saline soaked gauze
What is the definition of a "wound characteristic"?
foreign material in a wound
The meaning of "angiogenesis" is...?
formation of blood vessels
What is the term that means "things that often can delay wound healing"?
host/patient factors
Which phase is best for performing mechanical debridement?
inflammatory
How do corticosteroids impact wound healing?
inhibit diapedesis and decrease the inflammation response
What is the definition of epithelialization?
stage of wound healing in which epithelial cells form across the surface of a wound starting along the edge and working its way towards the center
How does chemotherapy impact wound healing?
suppresses bone marrow
How are lacerations treated?
usually primary intention unless heavily contaminated