Wound Healing Flashcards
The stages of wound healing are…
- hemostasis
- inflammation
- proliferation
- maturation (remodeling)
Describe the stage of hemostasis in the process of wound healing.
- endothelial injury → collagen:vWF–gp1b:PLT
- PLT actvx (ADP, TXA) → chemotaxis, GF
- vasoconstriction, PLT aggreg (gp2b/3a)
- inflammatory cell migration
Describe the stage of inflammation in wound healing.
- neutrophils - sterilize wound
- macrophages - phagocytosis FB, bacteria
- help signal fibroblasts
- T lymphocytes
Describe the stage of proliferation in wound healing?
- fibroblasts
- collagen (III) synthesized, deposited into matrix
- cross-linked - hydroxylysine/hydroxyproline
- need vit C
- disorder leads to scurvy
Describe the stage of remodeling in the wound healing process.
- begins at 3 weeks
- III collagen replaced by type I
- disorganization → keloids, hypertrophic scar
What cell type orchestrates the repair process? How?
Macrophages
Secretion of multiple growth factors for healing
How does diabetes affect the healing process?
Diabetes causes microvascular occlusive disease, which disrupts and delays the healing process.
What concentration within a chronic wound is enough to affect wound healing?
Chronic wounds may become colonized by bacteria. Bacterial contamination with greater than 105 organisms per gram of tissue may cause infection and delay healing.
What cofactor aids in the hydroxylation of proline and lysine? What wound healing process does this affect?
Vitamin C
Collagen cross-linking
What vitamin may reverse the impaired healing that chronic steroids creates?
Vitamin A
In reference to wound healing, zinc deficiency is associated with what?
Poor epithelialization
Broadly, factors that influence wound healing include…
infection, nutrition, perfusion, steroids/immunological imbalances affecting inflammation, and radiation.
In wound healing, what is primary intention?
Wound edges are approximated
How long does it take epithelizalization to take place in primary intention?
48 hrs
Remove bandages at this time postop
80-90% of vascular leg ulcers are from what?
venous insufficiency
Pressure ulcers develop over bony prominences. Which are the most common?
sacrum, ischeum, greater trochanter
Generally, how does radiation affect human tissue?
slow and inhibit wound healing
radionecrosis of soft tissue and bone
In general, how should do you identify and manage infected wounds?
- fever, tenderness, erythema, edema, drainage
- open, drain fluid, debride necrosis
- abx considered if systemic signs or high risk
What can help in the healing of ischemic wounds?
irradiated tissue?
diabetic ulcers?
revascularization
hyperbaric oxygen
glucose control
A 23-year-old paraplegic woman presents with an open wound over the sacrum. The wound appears to have necrotic debris at the base. She does not have a fever, but the wound has a foul odor. How would you approach examination and management of this wound?
- Pressure ulcers: develop over bony prominences, are more common in immobile patients.
- Desiccation causes necrosis in the base of wounds.
- Debris in the base prevents healing, nidus for infection.
- Tx: debride to create a moist/clean wound, cx
- if deep, eval for osteomyelitis
- Tx 2: if systemically ill or cellulitis, give abx
- Tx 3: Off-load w/ repositioning; air mattress, nutrition
- Tx 4: If stool is contaminating, may need diversion
A 72-year-old woman recently received a diagnosis of breast cancer and underwent left total mastectomy and sentinel node biopsy. Then she underwent immediate reconstruction with tissue expander implants followed by radiation therapy. She presents to your office with erythema, drainage, and dehiscence of the lateral edge of the wound. How would you approach the management of this wound?
- Radiation and chemotherapy impair wound healing
- Tx: abx, debridement, removal of infected FB
- Mgmt: hyperbaric therapy, negative pressure therapy
- Surg: autologous tissue flaps can be considered
An 87-year-old woman with chronic mesenteric ischemic disease underwent exploratory laparotomy and right hemicolectomy. Postoperatively, she developed a severe ileus requiring extended nasogastric decompression. On postoperative day 10, the nurse notes that there is fullness and increased drainage from the inferior edge of the incision. How can wound healing best be optimized in this patient?
- poor nutrition can diminish wound healing and increase risk of wound dehiscence
- initiate early feeding in stable pts w/ continuity
- NPO)for significant periods may need TPN
