Wound Healing

Card Set Information

Wound Healing
2014-01-07 15:35:55
Wounds IntrotoSurgery

Dr. Moore TUSPM intro to durg
Show Answers:

  1. keratohylin
    • protein precursor to filaggrin
    • found in the s. granulosum
  2. filaggrin
    acts as glue to stabilize s. granulosum
  3. What are ogland bodies and where are they found?
    • large amount of protein-bound lipids
    • s. lucidum
  4. where does keratinization begin?
    s. spinosum
  5. Adnexa
    • specialized appendages regulating:
    • -temperature
    • -evaporation
    • -touch
    • -pain stimuli

    • Adnexa include:
    • -hair follicle
    • -apocrine sweat glands
    • -eccrine sweat glands
    • -sebaceous glands
    • -nerves of epidermis
  6. ›Dermis
    • Separated from epidermis by basement membrane
    • Intricate connective tissue network 75% collagen
    • Elastic 
    • Accommodates:
    • -Nerve bundles
    • -Sensory receptors
    • -Lymphatic's
    • -Vascular elements
  7. Fibroblasts
    • Maintains structural integrity of dermis
    • Vital to wound healing & scar formation
    • Synthesize connective tissue proteins for collagen & elastin
    • Synthesize ground substance matrix for glycosaminoglycans
  8. Relaxed skin tension lines
    • Related to underlying musculature & osseous structures
    • Associated with creases in the skin with normal flexion and extension
    • Greatest ability to stretch and relieve tension in perpendicular direction to RSTL
    • Not greatly defined in foot and ankle
    • Lines of maximal and minimal movement
    • Very important in incisional approach and wound healing
    • If an incision is placed perpendicular to RSTL then maximum tension = stretched and hypertrophic scar
    • Incisions parallel or within RSTL = less tension and scarring
    • If cannot be within RSTL make incision in an oblique fashion
  9. Incision Planning
    • If allowable incision should be within RSTL
    • If not attempt for oblique to RSTL
    • If crossing a joint try and curve incision
    • Consider preoperatively:
    • -Skin characteristics
    • -Underlying anatomic structures
    • -Location of incision
  10. What normal object is NOT seen on radiograph?
  11. vaccume assisted closure of a wound
    • 130 mmHg continuous
    • Sub atmospheric pressure
    • Utilizes negative pressure to promote wound healing.
    • Wound dressing “open cell” foam surface to promote granulation tissue.
    • Can be used for variety of chronic and acute wounds
  12. Hyperbaric oxygen
    • Can be used to promote granulation tissue
    • Stimulates angiogenesis.
    • Oxygenation levels greater than 40mm Hg required for wound healing.
    • Less than 30mm Hg results in impaired oxygenation and decreased wound healing.
    • HBO increases oxygenation to soft tissues.
    • Improves neutrophil function, facilitates fibroblast cell division, increases collagen formation, and increases capillary budding
  13. How many organisms for a wound to be consider infected?
  14. Positive wound cultures of surgical wounds as high as _____%?
  15. What are the 2 most common species of bacteria to infect a wound?
    staph and strep
  16. Post op infection rate for clean, uncontaminated surgery is _____%:
  17. what is the triad for wound infection?
    • receptive host
    • contamination of microorganisms
    • wound culture medium
  18. Wagner Classification of Wounds:
  19. What factors help platelets initiate inflammatory stage?
    PDGF and TGF-B
  20. Macrophage Production of additional cytokines:
    • FGF
    • Interlukin-1
    • Tumor necrosis factor alpha
  21. What are the 4 stages of wound healing?
    How long does each last?
    • 1. Hemostasis: instantly- minutes
    • 2. Inflammation(Substrate): Last 5-7 days
    • 3. Proliferative: Day 5-21
    • 4. Remodeling: 3 wks- 1 year
  22. 2. Inflammatory stage
    • Begins at incision/injury
    • Lasts 5-7 days
    • Neutrophil migration
    • Macrophage migration
    • Cytokine secretion and recruitment of fibroblasts and endothelial cells
  23. When do neutrophils get to a wound?
    24 hours
  24. Proliferative Stage (3)
    • 5-21 days
    • Fibroblast migration and proliferation
    • Collagen deposited
    • Endothelial cells assemble microvascular structures
    • Glycosaminoglycans make up the connective tissue matrix
    • Loose matrix of collagen, fibronectin and hyaluronic acid
  25. When do fibroblasts peak?
    1 week
  26. Remodeling stage
    • ≈3 weeks – 1 year
    • Lattice like collagen network
    • Laying down of scar tissue
    • Transformation of capillaries and fibroblasts to relatively acellular type I collagen bundles
  27. What types of wounds is contraction most efficient on?
    small wounds
  28. What does contraction begin on a wound?
    following 3-4 days
  29. Describe Re-epithelialization:
    -Begins within hours of injury

    -Initiated by platelet release of epidermal growth factor

    -Begins at wound edge and migrates centrally

    ›-Continues until epidermal surface is completely restored
  30. What is a major disadvantage to epithelialization?
    • unstable quality of final wound and fragility
    • *any for of minor trauma can cause recurrent ulceration
  31. What is peak tensile strength in a wound?
    60 days post injury
  32. A healed wound will reach approx ___% of tensile strength
  33. How does hyponatremia affect wound healing?
    delay fibroblastic activity--> decreased wound strength
  34. What does Vitamin C do in wound healing?
    • Ascorbic acid
    • Vit C and iron are required for hydroxylation of lysine and proline (collagen)
    • Vitamin C and Lysine which crosslink and stabilize the triple helix structure of collagen
  35. What does Vitamin A do in wound healing?
    • retinoic acid
    • modulates collagen production and degradation
  36. What is Vitamin E role is wound healing?
    • potent antioxidant
    • alpha tocopherol
    • accelerate dermal and bone healing
  37. Zinc in wound healing
    deficiency related to poor wound healing if deficient
  38. What will happen is a diabetics insulin is >200mg/dl?
    • decrease in phagocytosis
    • decrease in killing of bacteria
  39. What are some complications to diabetic wounds? (intrinsic factors)
    ›-Microvascular disease 

    ›-Decreased host resistance to bacteria

    • ›-Metabolic differences – hyperglycemia and
    • insulin deficiency/resistance

    • ›-BS > 200mg/dl = ↓ phagocytosis and
    • decreased killing of bacteria

    ›-Insulin deficiency = ↓ collagen production and wound tensile strength

    ›-Decreased fibroblast reproductive capability
  40. How does insulin deficiency affect wounds?
    decrease collagen production and wound tensile strength
  41. What are some extrinsic factors of wound healing?
    • Infection: 
    • ›-Competes with new tissue for nutrients and oxygen
    • ›-Lactic acid production lowers pH and furthers tissue breakdown

    • ›Smoking!
    • -vasoconstrictive effect due to nicotine
  42. How does hypovolemia affect wound healing?
    decreased oxygenation
  43. Glucocorticosteroids affect on wounds healing(6):
    Extrinsic factors
    ›Inhibit cellular proliferation 

    ›Inhibit tissue growth

    ›Inhibit inflammatory reaction

    ›Inhibit fibroblasts proliferation

    ›Inhibit epithelization

    ›Reduce collagen production
  44. How do steroids affect wound healing?
    • Steroids break down tissue fat and proteins and
    • thus inhibit cellular proliferation, tissue growth and DNA synthesis.
  45. What stage do steroids have greatest effect?
    inflammatory stage
  46. Antimicrobials(3) and wounds

    ›Acetic acid

    ›Hydrogen peroxide
  47. Hydrogen Peroxide and negative effect on wound healing(4):
    -Cytotoxic to bacteria and host tissue 

    -›Retards wound epithelialization

    -›Can lead to necrosis and decreased microcirculation

    ›-May allow invasive flora to overtake normal inhibitory flora of wound
  48. Warafin
    ›Blocks  formation of vitamin K and vitamin K dependent clotting factors
  49. Heparin
    inactivate thrombin inhibiting blot clotting
  50. Aspirin
    decreases platelet aggregation
  51. What is an exudate?
    fluid that filters from circulatory stem to a wound
  52. What are 4 things an exudate may contain?
    • plasma proteins
    • WBC
    • RBC
    • Platelets
  53. What do exudates due? (4)
    • Dilute toxins of dead cells
    • limit use; prevents additional injury
    • provide blood cells and nutrients to site of injury
    • carry away toxins and waste
  54. Serous wound exudates (4)
    • mild inflammation
    • usually clear
    • little protein
    • like water
  55. Purulent Wound Exudates(7)



    ›-Necrotic tissue

    ›-Yellow to green


    ›-Often has odor
  56. Fribinous Wound Exudates (3)
    • Fibrinogen and fibrin
    • white to yellow in color
    • thin
  57. Hemorrhagic wound exudates (2)
    • RBC
    • Thick
  58. Inflammation fever is caused by what?
    release of cytokines in acute phase
  59. inflammation leukocytosis is caused by what?
    migration of neutrophils to phagocytose debris