Skin/Wounds Flashcards
Wounds can be classified into four types based on the degree of contamination. Name one example for each type.
1) Clean: surgical incision
2) Clean-contaminated: surgical entry into the GI tract
3) Contaminated: Bite wound
4) Dirty/Infected (contains > 10^5 organisms per gram of tissue; time frame is > 6hrs): Abscess
How strong is a scar tissue compared to normal tissue?
80% of normal tissue
Describe four stage of wound healing, the onset time and the hallmark for each phase.
1) Inflammation
- immediately after injury, lasting for about 5 days
- Hemorrhage, blood clot formation, inflammatory cytokines enter the wound (e.g. histamine, prostaglandin, leukotriene, growth factor, complement)
2) Debridement
- Simultaneously as inflammation phase
- Hallmark: WBCs enter the wound
- Neutrophils enter the wound first (within 6 hours of injury)
- Monocytes enter the wound at around 12 hours after injury, become macrophages at 24-48 hours post-injury.
- Macrophages stimulate fibroblasts activation, collagen synthesis and angiogenesis
3) Repair/Proliferation
- starting at 3-5 days post-injury and last for 2-4 weeks
- Hallmark: angiogenesis, epithelialization, granulation tissue formation
4) Maturation
- Starting at 17-20 days post-injury and can last for years
- Hallmark: wound contraction, remodeling of collagen fiber bundles
What is the goal for wound management?
Providing healthy wound bed and good blood supply for tissue healing
If you need to use chlorhexidine to flush a very dirty wound, what is the recommended concentration?
0.05%
(1 part of 2% Chx to 40 part with saline)
What are the functions of the three layers of the wound bandage?
1) Primary: dressing directly contact the wound
- Adherent (for mechanical debridement) vs Non-adherent (provide/maintain moist environment in the wound and facilitate healing)
2) Secondary
- Padded materials to cover the primary layer and aid in absorb excessive discharge
3) Tertiary
- Protective effect and hold the first two layers in place
What is the contraindication for calcium alginates dressing?
Do not use when the tendon, bone or necrotic tissue are exposed.
When is the time to discontinue hydrogels?
When healthy granulation tissue is present
(it can promote exuberant granulation)
What is the definition of secondary wound closure?
The wound is closed 5 or more than 5 days after the initial injury, when granulation tissue has formed in the wound bed.
What is the definition of second intention healing?
The wound is left open and rely on wound contraction and epithelialization to close it.
What is the common pressure set for negative pressure wound therapy?
-125mmHg
What are the contraindications for negative pressure wound therapy?
1) Exposed vessels
2) Exposed organs
3) Exposed nerves
4) Exposed anastomotic site
5) Active hemorrhage or patient with bleeding disorder
6) Necrotic tissue with eschar present
7) Untreated osteomyelitis
8) Malignancy in the wound
9) Nonenteric and unexplored fistulas
What are the components of provisional and definitive extracellular matrix?
Provisional:fibrin, fibrinogen, fibronectin, vitronectin
Definitive: collagen, elastin, hyaluronic acid
How long does it take for GI mucosa to heal with direct apposition?
3 days
True or False: During wound irrigation, copious amount of solution is more important than the sterility and antimicrobial property.
True