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Flashcards in Wound Healing Deck (15)
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1

What are the four stages of wound healing?

1. Hemostasis/Coagulation (fibrin)
2. Inflammation (PMNs in the first 24h, Mfgs in 48h)
3. Migration/Proliferation (collagen, fibroblasts)
4. Remodeling

2

Coagulation
-what comprises a thrombus?

Thrombus
-fibrin threads, erythrocytes, platelets

3

Inflammation
-What cells are involved?
-what is the function of the cells?

Cells
-Neutrophils
--bacteria and matrix phagocytosis

-Mfgs
--phagocytosis, wound debridement, cell recruitment and activation, angiogenesis, matrix synthesis regulation

4

Migration/Proliferation
-describe angiogenesis
-describe epithelization
-role of keratinocytes
-describe fibroplasia

Angiogenesis
-formation of vessels; endothelial cell buds follow oxygen gradient, differentiate into capillaries, arterioles, and venules. Mfgs and keratinocytes provide angiogenic stimuli

Epithelization
-Keratinocytes migrate across wound; during migration differentiation occurs.
-Epithelization aided by moist environment

Keratinocytes
-migration/proliferation, ECM production, growth factor/ cytokine production, angiogenesis, protease release

Fibroplasia
-fibroblasts migrate into wound site and replicate, synthesize and deposit collagen and proteoglycans
*matrix deposition is dependent on oxygen and substrate availability as well as growth factors

5

What is the dominant cell type at the wound edge?
What is that cells role?

Fibroblasts, yo.

Role
-migration/proliferation
-ECM production
-Growth factor/cytokine production
-angiogenesis
-Protease release

*This is the same as keratinocytes! The difference lies with the growth factors they release

6

Remodeling
-explain the changes in matrix composition over time

extracellular matrix... collagen... scar

7

Summing it up...
What cell types are involved in each stage
-coagulation
-inflammation
-migratory/proliferation
-remodeling

Coagulation
-platelets

Inflammation
-platelets
-mfgs
-neutrophils

Migratory/proliferative
-mfgs
-lymphocytes
-fibroblasts
-epithelial cells
-endothelial cells

Remodeling
-fibroblasts

8

Factors that may cause slowed healing

Local factors that affect wound healing

Slowed
-ischemia
-dry wound environment
-infection
-foreign bodies
-anti-inflammatory therapy
-nutritional deficiency

Local factors
-mechanical injury
-infection
-edema
-ischemia
-topical agents
-ionizing radiation
-low O2 tension
-foreign bodies

9

Essential nutrients for wound healing

-calories
-carbs
-protein
-fats
-Vit A, C
-Zinc (Most important mineral for wound healing)
-Water

10

What are Halsted's Principles?

-gentel handling of tissues
-careful hemostasis
-aspetic technique
-avoidance of tension
-sharp dissection
-obliteration of dead space

11

What is healing by primary intention?
secondary?
Third?

Primary: sutures, staples, pulling everything together nicely, covered with sterile dressing

Secondary: wound is not closed and allowed to granulate, slow healing, need a drain or daily wound care

Third: cleaned, I and D, left open for 4-5 days, and then closed

12

Benefits of the V.A.C.

Decrease edema

Enhances granulaiton and vascularity

Lower bacterial counts

13

Surgical site infections
-definition
-SSIs are the most common what
-MC bug
-pt related risk factors

Definition
-refer to infection at incision site, but also infections that extend to adjacent deeper structures

Most common nosocomial infection

MC bug is staph aureus and coag neg staph

Risk factors
-DM
-Obesity
-smoking
-systemic steroids or other immunosuppressive drugs
-malnutrition
-pre-op nasal carriage or colonization w/ staph aureus
-presence of remote focus of infection
-duration of preoperative hospitalization
-preop servity of illness of pt

14

What are the three most important factors for prevention of SSIs?

-general health of pt

-meticulous operative techniques

-timely administration of pre-op antibiotics

15

Abx prophylaxis for colorectal surgery
-route
-drugs

Route
-oral
-IV
-both

Drugs
-Oral: neomycin and erythromycin w/ bowel prep
-IV: cefoxitin or cefotetan or (cefazolin PLUS metronidazole)