MGMT Of Traumatic Wounds- Fundamentals Flashcards
4 stages of wound healing?
- Inflammatory phase
- Debridement phase
- Repair
- Maturation/remodeling phase
What phase of wound healing is characterized by:
Increased permeability of local blood vessels,
Recruitment of circulatory cells,
Release of growth factors/cytokines,
Activation of neutrophils, lymphocytes, fibroblasts, and MFs
And is 0-5 days….
Inflammatory
What initiates the debridement phase?
WBCs leaking from blood vessels into wounds;
Specifically, the arrival of neutrophils (~6hrs post-wound) and monocytes (~12 hrs)
What is the major secretory cell most essential for wound healing?
Monocyte! Synthesize growth factors that participate in tissue formation and remodeling
What cells stimulate monocytes?
Neutrophils
What phase is associated with the development of an exudate rich in WBCs, wound fluid, and necrotic tissue within a wound bed?
Debridement Phase
What cell type:
- Secretes collagenases (removing dead tissue, bacT, etc)
- Secretes chemotactic and growth factors (complement, endotoxins, TGF-alpha/beta, IL-1, etc)
- Recruit mesenchymal cells, stimulate angiogenesis, and modulate matrix production in wounds
Macrophages
Where does Basic Fibroblastic Growth Factor (BFGF) comes from and what is its role?
Macrophages/Monocytes, T-lymphs;
* Promotes angiogenesis, granulation, epithelization via endothelial cell, fibroblast, and keratinocyte migration (respectively) *
Where does vascular endothelial cell growth factor (VEGF) come from and what is its role in wound healing?
Endothelial cells! Promotes angiogenesis during tissue hypoxia
Where does Epidermal Growth Factor come from and what is its role in wound healing?
From Platelets and macrophages;
Stimulates fibroblasts to secrete collagenase to degrade the matrix during the remodeling phase. Stimulates keratinocyte and fibroblast proliferation
Where does TGF come from and what is its role in wound healing?
Macrophages, Platelets, Lymphs, and Hepatocytes;
Attracts neutrophils/macrophages, promotes angiogenesis, up-regulates collagen production, and inhibits degradation
Where does Keratinocyte Growth Factor (KGF/ aka Growth Factor 7) come from and what is its role in wound healing?
Fibroblasts;
Stimulates keratinocyte migration, differentiation, and proliferation
Where does Platelet-Derived Growth Factor (PDGF) come from and what is its role in wound healing?
Platelets, macrophages, endothelial cells;
Attracts neutrophils/macrophages,
Promotes collagen and proteoglycan synthesis
In the Repair Phase (3-5 days to 2-4 weeks), what do macrophages stimulate?
Fibroblast and DNA proliferation
What does the combination of fibroblasts, new capillaries, and fibrous tissue development result in?
Bright red, fleshy GRANULATION TISSUE! (3-5 days after wounding…)
Granulation Tissue is an excellent barrier to infection, provides a surface for epithelial migration, but also serves as a source of special fibroblasts, used in wound contraction - what are they called?
Myofibroblasts
When does epithelialization begin in sutured wounds?
24-48 hours
When does epithelialization begin in an open wound?
Within 4-5 days
During wound contraction of the Repair Phase, what is the approximate rate of progression (mm/day)?
0.6–0.8mm/day
What is the approximate rate of granulation tissue formation at each wound edge during the Repair Phase (mm/day)?
0.4-1mm/day
What is the “Golden Period” within wounding, where there’s insufficient microbial replication to cause infection and can usually manage with primary closure?
Within 0-6 hours!!!
“Class 1” - minimal contamination or tissue damage
What class of wound would microbial replication be at critical level allow for infection (>12 hours of wounding)?
Class 3 :(
What type of wound management should we use for Class 1 (and some 2) wounds?
Primary closure (1st intention)
What type of wound management would involve appositional closure before granulation tissue develops (w/in 3-5 days of wounding)? Good for Class 2 wounds…
Delayed Primary
What type of wound management involves appositional closure after granulation tissue as developed (>3-5 days after wounding)?
Secondary Closure
What type of wound management involves healing by contraction/epithelialization and open wound management (OWM)?
Second Intention Healing
What ratio of chlorhexidine (To water?) should you use as a lavage solution at 0.05%?
1:40
What ratio of povidone-iodine (to water?) should you use as a lavage solution at 0.1%?
1:100
What is the historic standard recommended technique for initial wound irrigation?
Use of a 35-mL syringe and 18G needle and pressure from 7-8 psi
What pressure adequately REDUCES bacT contamination from wounds?
1.6 psi
What pressures can cause barotrauma?
Pressures >25 psi
What is the most consistent technique for generation of 7-8 psi in wound flushing?
1L Saline solution bag placed in a pressure cuff at a cuff pressure of 300 mmHg
