Wound Healing 2 Flashcards
What processes are important for regaining strength in a wound?
- Collagen production - begins at 10 hours in healing wound (peaks at 5-7 days)
- cleavage of procollagen and cross-linking - increases tensile strength
Major advantage of skin graft?
For skin graft to attach successfully, necessary bacterial count on granulation bed?
Disadvantage of skin graft?
Reduce wound contraction by 60%
<100,000/gram tissue
Fragile, easily disrupted, and always remain more susceptible to trauma
Contraction of a wound occurs due to? What is a contracture?
Fibroblast contract with smooth muscle cells (myofibroblasts)
Distortions of normal anatomy due to scarring
Growth factors most important in healing process?
- Platelet derived growth factor – chemotactic for fibroblasts, neutrophils, macrophages
- Transforming growth factor B – increases collagen synthesis
- Basic fibroblast growth factor – hastens wound contraction
- Epithelial growth factor – speeds up wound epithelialization
Classifications of surgical wounds (regarding potential infection)? Describe surgery?
- Clean wound (<3% chance of infection) – G.I., respiratory, or GU tract is entered, but is prepared both mechanically and antibacterially
- Contaminated wound – (5% chance of infection) – gross spillage of stool from the colon, infection in the biliary, respiratory, or GU system
- Infected wound (50% chance of infection) – infection before a wound is made in the skin
Which patients should receive IV antibiotics preoperatively? How are they given?
- Clean contaminated cases,
- implantation of permanent foreign body
- impaired host defenses
- Impaired blood supply
single-dose (1-2.5*t1/2 hours) preoperatively and single-dose post operatively
Patient with animal bite – type of wound? General Management? Exception?
Contaminated; left open
Unless in areas with particularly rich blood supply (face)
