Wound Healing Flashcards
Primary cell types in the inflammatory phase
Neutrophils and Macrophages
Primary cell types in the proliferative phase
Fibroblasts
Granulation tissue: collagen and fibroblasts
Contraction: myofibroblasts
Primary cell type during maturation phase
Lymphocytes and collagen
`describe the inflammatory phase of healing
This phase exhibits the cardinal signs of inflammation caused early on by neutrophils and then macrophages on days 3-5. Blood clots form during this phase and there may be more purulent exudate.
Describe the proliferative phase of healing
This phase starts at day 4 with fibroblasts and is characterized by granulation tissue (collagen and fibroblasts) and epithelialization around the wound edge. Then myofibroblasts start contraction.
Describe the Maturation Phase of healing
This is the final remodeling, where the skin will never regain more than 80% of original strength
What solutions are appropriate for lavage?
Tap water, 0.9% saline, any IV fluid that is not hydrogen peroxide
What are some recommended lavage additives?
Chlorohexidine solution 0.05% and Povidone Iodine solution 0.1-0.2%, but don’t use scrub
__ is critical for neutrophils to kill bacteria and for collagen production
Oxygen
What are the steps for initial wound treatment?
- Clip and clean skin
- Lavage
- Debride
- Culture
Use good biosecurity to prevent into and spread of disease or bacterial resistance
What is the goal of lavage?
The most effective way to reduce bacterial numbers on the surface of the wound
Antibiotics (topical and systemic) are most commonly used during the __ phase and not necessarily during the __ phase
Inflammatory phase, proliferative phase
To obtain cultures you should know __ you got the sample and want __ or more samples.
When, 2-3
When should you close a wound?
When there is good blood supply, no infection, sufficient skin for tension free closure, minimal health risk for anesthesia/surgery, financially and clinically beneficial and when there is a high likelihood of healing success
Primary closure
First intention healing where the wound is sutured soon after injury
Contraction and epithelialization
Second intention healing where the wound heals naturally without sutures and may be used for very small or very large wounds when primary closure has failed
Secondary closure
This is third intention healing where the wound is closed later than 5 days after injury when granulation tissue is present. This may be used in severely infected wounds or wounds with massive tissue destruction.
Describe the layers of building a bandage briefly
- Primary layer: this is the dressing or contact layer that manipulates the wound environment
- Secondary layer: this plays a role in absorption, stabilization and pressure +/- a splint (support)
- Tertiary layer: provides additional protection, pressure and cosmetics
Inflammatory Phase Dressing Options
The goal of dressing here is to debride and reduce bacterial contamination:
- Wet to dry bandage
- Honey and sugar
Proliferative phase dressing options
The goal of dressings in this phase is to not disrupt the fragile new tissue and hold cells and cytokines in so we want something non adherent and occlusive:
- Petroleum infused gauze
- Telefax +TAB
- Honey/Sugar
- hydrogel (dry wounds)
- Polyurethane foam
- Calcium alginate (wetter wounds)
Describe the Wet to Dry bandage
This bandage should only be used during the inflammatory phase and requires sedation as application and removal can be painful. It’s indicated for wounds with necrotic tissue, foreign material and viscous exudate. It works by diluting the exudate, absorbing it and is removed when dry.
Honey and Sugar work well as dressings because they’re __ with a high ___ that draws water out causing bacterial lysis. Honey specifically has antimicrobial molecules related to ___
Antimicrobial, osmolarity, hydrogen peroxide
What are the benefits of keeping a wound moist?
- physiologically favors cell migration and matrix formation
- Accelerates healing of wounds by promoting autolytic debridement
- Reduces pain
What is the role of wound exudate?
The growth factors and cytokines modulate healing. Metalloproteinases promote degradation of fibrin clot and eschar
Hydrogels and Hydrocolloids should be used on __ wounds to provide moisture
Dry
Calcium alginate is a __ wound dressing that promotes autolytic debridement and __ tissue. It requires large amounts of wound fluid to hydrate and become gel
Moist, granulation
What are some less expensive alternative for dressings?
TELFA pad with triple antibiotic ointment and petroleum impregnated gauze
Bandage changes become __ frequent during the proliferative phase
Less
