Second intention healing Flashcards
What are the key components of second intention healing?
- granulation
- contraction
- epithelialization
How does the phases of wound healing in second intention differ from first intention (sutured wounds)
The phases are identical but the magnitude and duration of the CELLULAR phase is longer
How does contraction occur?
myfibroblasts (actin, fibronectin)
What are the two contraction theories?
- picture frame theory
2. pull theory
What are the limits to contraction? (3)
- contact inhibition
- opposing tension
- myofibroblasts disappear (large old wounds)
What is usually the greatest limit to contraction on limbs?
opposing tension
What can be done to old, large wounds to stimulate contraction?
scrape the granulation tissue/wound to cause upregulation of myofibroblasts
What is the rate of contraction on the body?
1mm/day (each side)
What is the rate of contraction on the limbs?
0.2mm/day
why is contraction slower on the limb?
- inelasticity of skin
- vascular insufficiency
- fewer myofibroblasts
- cytokines
What is the rate of epithelialization on the body?
0.2mm/day
What is the rate of epithelialization on the limb?
0.09mm/day
Why is epithelialization slower on the limb?
unknown
Why don’t you see epithelialization until contraction has pretty well stopped?
because contraction occurs faster than epithelialization so it is just like the trickle in front of a wave and don’t see significant epithelialization until contraction pretty well stops
How do you prevent exuberant granulation tissue?
- debridement
- sterile dressing
- pressure bandages
Why is prevention better than treatment with exuberant granulation tissue?
because once a wound becomes exuberant, it tends to keep being exuberant
What is the bandage philosophy in second intention healing?
- pressure bandage early to minimize swelling and reduce wound size–less retraction
What is the bandage philosophy in second intention healing?
- pressure bandage early to minimize swelling and reduce wound size–less retraction b.c less swelling
- after inflammatory phase it’s a catch 22-may stimulate more granulation tissue and slow healing but also provides mechanical protection–abandon bandage when can!
Which of the following healed best 1) no treatment 2) cryosurgery 3) bandage 4) cast
1) no treatment
What can be a problem with wound medications?
t get a medication passed for wound healing, just have to show that causes no harm
When is immobilization indicated?
- wounds in high motion areas
What requires critical observation?
equine sarcoids–horses are prone to develop equine sarcoids in areas of wounding. NOT granulation tissue–if trimmed will become more aggressive
How could you distinguish equine sarcoids and exuberant granulation tissue?
exuberant granulation tissue will eventually become exuberant over the whole wound
What are two ways that exuberant granulation tissue can be managed?
- sharp debridement
2. topical medicaments
What are 2 advantages of surgical debridement? How is hemostasis acheived?
- predictable result
- can repeat as needed
achieve hemostasis by pressure bandage. (minimize by doing a fast debridement)
In what direction do you go when performing wound debridement?
start from bottom and work way up
What are two advantages of topical medications for the management of exuberant granulation tissue?
- owner friendly
2. control granulation tissue
What is a disadvantage of topical medications for the treatment of exuberant granulation tissue?
- impede healing (slow contraction, slow epithelialization)
Does sharp debridement of exuberant granulation tissue slow healing?
no
What does topical corticosteroids do?
inhibit granulation tissue
(also slows epithelialization)
(judicious use)
What are common preparations of topical corticosteroids?
- panalog–$
- green wound cream–penicillin + corticosteroid–sensitization?
- 0.1% dexamethasone :)
What is white wound lotion?
lead acetate and zinc sulfate
Why is white wound lotion not good to use on wounds?
- metabolic toxins (lead acetate, zinc sulphate)
- kill fibroblasts
- slow epithelialization
- lead poisoning–not bandaged–lick–poisoned
What is the cheapest topical medication
copper sulfate (10% concentration mix with corn starch)
What is a negative effect of copper sulfate?
it is astringent/caustic and kills fibroblasts
What is a negative effect of copper sulfate?
it is astringent/caustic and kills fibroblasts
Which is preferred, topical corticosteroids or copper sulfate to manage exuberant granulation tissue? (if must be topical?)
corticosteroids
Is Furacin (nitrofurazon) a good choice for topical application on open wounds?
no,
- it causes granulation tissue. not a good choice on open wounds
- inhibits epithelialization
- harbors pseudomonas
What is preparation H?
it is yeast extract
What can preparation H (yeast extract) be used for?
to stimulate the production of granulation tissue early on (n long effects)
What is a negative consequence of preparation H?
slows contraction and epithelialization
What is a negative consequence of preparation H?
slows contraction and epithelialization
What is the effect of amnion as a topical medication?
as a wound dressing
- inhibits granulation tissue
- promotes epithelialization
- speeds healing
What is a problem with amnion:
not available commercially
What is the effect of honey as a topical medication?
- osmotic effect on bacteria–antibacterial
- unpasteurized my have enzymes to activate hydrogen peroxide
good to use in early wound management
What is the current data on collagen preparations as topical medications?
- no negative effects demonstrated
- so far no benefits
- expensive
What is biosyst?
procine small intestinal submucosa
What does biosyst have?
- collagen
- protepglycans
- cytokines
What is biosyst promoted as doing? Is there evidence of this?
- scaffold
- healing modifier
no good research to support
What are two benefits of using split thickness skin grafts?
- inhibit granulation tissue
2. promote wound contraction
What are three types of skin grafts?
- zenographs (pig)
- allografts
- autograft
Give an example where the medical preparation had an effect on wound healing
- gentamicin cream vs solution
trial revealed that the cream affected contraction and inhibited epithelialization. The solution caused faster healing
What is a good saying for what to put on a wound?
If you wouldn’t put it in your eye, don’t put it on a wound
What are examples of topical medications?
- corticosteroids
- white wound lotion
- copper sulfate
- furacin
- preparation H
- amnion
- honey
- collagen preparation
- biosyst
- split thickness skin grafts
If you see exuberant granulation tissue, what should you do?
look for a reason!