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Wound Healing 1
Surgery 2
Question | Answer |
---|---|
Biggest determining factor of whether wound will heal: | blood supply |
Phases of Wound Healing: | Hemostasis, plt plug / fibrin clot formation; inflam & recruitment; fibroblast proliferation & granulation; maturation (wound remodeling & contraction) |
Order of arrival of cells to newly injured tissue | Platelets; neutrophils; monocytes/ macrophages; fibroblasts |
Fn of Platelets: | plug any bleeding defects to form a clot, which provides a fibrous framework for later events. |
Cells that stimulate mast cells to release histamine: | Platelets and leukocytes |
Fn of Neutrophils: | phagocytosis of debris & release of cytokines to recruit other cells; die within 24-48 hrs; release lysosomal enzymes, which digest necrotic debris |
Fn of Monocytes/macrophages | arrive at approx. same time as neutrophils, but live longer and predominate after 3rd day |
Fn of Fibroblasts | appear at about 24 hrs; attach to fibrin scaffolding deposited in wound during initial clotting. |
Predominant cells in a normal wound at 10 days: | Fibroblasts |
Reasons for difficult healing in Diabetes: | Impaired microvasculature, impaired inflammatory response |
Reasons for difficult healing in Glucocorticoids: | Immunosuppression, reduced tensile strength |
Reasons for difficult healing in Radiation and Chemotherapy: | Arteriolar and fibroblast damage, BM suppression |
Treatment for an abscess is: | Drainage |
Primary closure: | prompt suture closure after irrigation; heals the most rapidly w/ the best scar; can be used in clean & clean-contaminated wounds; also clean, fresh traumatic lacerations. |
Secondary intention: | wound is left open & allowed to granulate in; generally involves debridement, irrigation, & frequent dressing changes |
Delayed primary closure: | wound is cleaned, debrided, irrigated, & closed 3 to 5 days later |
Cofactors required for collagen synthesis | Vitamins C&E; Iron; Oxygen; Protein; Galactose; Glucose; Manganese |
Wound: Clean: | non-traumatic, uninfected, incision under aseptic conditions as in the OR; e.g. median sternotomy incision, hernia; infection rate < 5% |
Wound: Clean-contaminated: | normal flora, wounds involving oral cavity, respiratory, upper alimentary, or GU surgery; e.g. esophageal, cholecystectomy, colectomy; infection rate < 10% |
Wound: Contaminated: | fresh traumatic lacerations, operative procedures with gross soilage; ex: colostomy, bowel resection w/ enterotomy; acute cholecystitis w/ pus; infection rate < 15% |
Wound: Dirty/Infected: | heavily contaminated wounds, traumatic wounds greater than 6 hours old, grossly infected wounds; ex: pelvic abscess, gangrene of extremity, perf viscus, perirectal abscess, leg ulcer; infection rate 30% |
Factors that Influence Healing: | Infection/ contam; Nutrition; DM; Jaundice; Uremia; Steroids; CT/radiation; Hypoxia (smoking); edema |