What are the 3 overlapping phases of normal wound healing
- inflammation
- proliferation
- maturation
the inflammatory phase of wound healing lasts how long
0-5 days
the inflammatory phase of wound healing has what 2 parts
- vascular stage
- hemostasis: stop bleeding
- cellular stage
- migration of WBC first 48-72 hrs
- macrophages enter at 72 hrs: phagocytic and stimulate collagen production
What are the 3 parts of the intermediate phase of wound healing
- epithelialization
- angiogenesis
- fribrobalst migration and proliferation
what is epithelialization and when does it occur
- re-establish barrier
- incisional wounds re-epitheliazed in 24-48 hours
- pt can shower after this itme
what are the 4 components of late phase of wound healing
- matrix deposition
- collagen synthesis
- collagen fibers thicken
- wound contraction
what type of collagen is the most common in wound healing
type I collagen (80-90% of collagen found in normal skin
when does collagen synthesis begin? When does it start to decline?
- begins 3-5 days following injury
- rapid rate up to 4-5 weeks, then rate declines
What does wound strength depend on
- strength of wound parallels rapid rise in collagen for approx 4 weeks
- at 6 weeks, scar has reached 80% of eventual strength
remodeling increases strength of wound for how long
up to 2 years
what temperature reduces tensile strength of wound healing
cold reduces tensile strength
What is primary intention wound healing
- closed by approximation of wound margins
- closure methods: sutures, staples, adhesion
- heal fastest
What is wound healing by secondary intention
- applies to a full thickness wound or contaminated or infected wounds
- wound left open
- allowed to close by contraction and epithelialization
What is tertiary intention of wound healing (delayed primary closure)
- wound left open for days (3-5) then closed primarily
- granulation tissue is abundant
- highly resistant to infection
- associated with obvious infection or contamination
puncture wounds usually healed by what intention
secondary
lacerations are usually closed within how many hours
within 6-8 hours
differentiate between monofilament and braided sutures
- monofilament: less reactive
- braided: more strength
what is the benefit of interrupted sutures
- slower to place but will allow selective removal in case of infection
when are continuous sutures used? What is the down side to them?
- used for clean wounds
- fast to sew, easy to remove
- wound integrity is compromised if secondarily infected
what are the advantages and disadvantages of staples
- advantage: fast, individual stapes can be removed in event of infection
- disadvantage: “railroad track pattern”
clean surgical wounds should have wound dressings left in place for what period of time? why?
- 48 hours to allow for epithelialization
- removed earlier if saturated or suspicion of infection
What type of wounds are left open
- bite wounds
- > 8 hrs since injury
- face is exception
- necrotic tissue or foreign material
- high velocity injuries
- inflammed or infected wounds
- crush or ischemic tissue
- high level steroid use
What type of bite wounds are considered infected wounds
- human bites
- cat bites
avoid using epinephrine to control bleeding in what areas
- ears, fingers, toes, nose, penis
