Tissue Integrity & Wound Healing Flashcards
partial thickness wound
damage thru epidermis
dermis intact
full thickness
damage thru epidermis and dermis
can extend into subcutaneous tissue, muscle, bone
scar fomation
wound healing depends on
type of injury
extent of tissue loss
infection, necrotic tissue (does not regenerate), secondary tissue breakdown
primary intention
primary closure surgical closure of wound repair: formation of new extracellular matrix regeneration: re-epithelizalization little granulation tissue
secondary intention
secondary/spontaneous closure full thickness wound that heals w/out closure attempt large amount of granulation tissue longer healing time, larger scar skin grafting, skin substitues
tertiary intention
delayed primary closure
combination of primary/secondary intention
contaminated wound cleaned, left open to drain
scarring > primary intention
phases of wound healing
hemostasis
inflammatory
proliferative
remodeling
role of chemical mediators
cytokines (initiate healing process, produce growth factors/cytokines, stim expression of GF, develop ECM , coordinate intercellular communication) growth factors (stimulate growth/division/differentiation of other cells, regulate intercellular communication) nitric oxide (direct: bacterial killing, indirect: modulates cytokine/growth factor activity)
Inflammatory stage
4-6 days
minimize tissue damage, prevent additional tissue injury, prepare wound for healing & regeneration
steps: hemostasis, platelet adhesion, platelet activation, platelet plug, fibrin clot formation, recruitment of phagocytic cells & wound debridement)
proliferative stage
4-24 days
wound healing guided toward tissue repair
granulation tissue (foundation for collagen-based matrix that replaces fibrin-based provisional matrix)
fibroblasts (produce collagen, adhesive proteins for ECM)
myfibroblasts
endothelial cells (angiogenesis - neovascularization)
re-epithelialization (regeneration of keratinocytes)
remodeling
21 days - 2 years
epidermis maturation
wound contraction
apoptosis and scar maturation
factors that impede wound healing local
blood flow & hypoxia infection radiation exposure movement/tension desiccation excessive edema denervation
factors that impede wound healing systemic
adv age malnutrition nutritional status immune deficiency smoking medications metabolic status
hypoxia
delays/stops wound healing process greatest at center of wound leading cause of wound infection amplified by infection inhibits fibroblast activity/collage deposition in matrix
wound healing & nutrition
major role in wound healing
essential CHO, fats & proteins
effects of negative nitrogen balance: impaired immune/inflammatory response, delayed healing
vitamin A deficiency
impairs re-epithelialization deposition of collagen/fibronectin
impedes inflam process
impairs WBC FX/angiogenesis
vitamin C deficiency
impairs inflammatory process
inhibits collagen secretion
increases localize infection
vitamin K deficiency
affects hemostasis & formation of fibrin clot
zinc deficiency
leads to decreased fibroblast proliferation & collagen synthesis, epidermal cell poliferation
MG/CU/FE deficiencies
affect protein synthesis & cellular proliferation
corticosteroids & wound healing
promote breakdown of CHO/fats/protein
anti-inflammatory action impedes inflam phase of wound healing
antineoplastic drugs & wound healing
potent immunosuppressants
impairs re-epithelizlization granulation tissue formation angiogensis
diabetes & wound healing
insufficient insulin/insulin resistance or both
hyperglycemia = chronic macrovascular disease, atherosclerosis (tissue ischemia & hypoxia), thickening of basement membrances: diabetic lesions
impaired FX/reduced ability to fight infection
sensory neuropathy, reduces pain sensation r/t wounds
Fibrosis
excessive wound healing
replaces normal tissue
nonfunctional collagen/scar tissue
excess synthesis/delayed degradation
Keloids
excessive wound healing
lesions of dermal scar or fibrotic tissue
Hypertrophic scars
excess fibrotic tissue
raised above level of surrounding skin
grows w/in boundaries of original injury (regress spontaneously)
contractures
abnormal exaggeration of wound contraction
shrinking scars severely deform wound, reduces mobility
compromise mobility of involved joints
wound dehiscence
deficient wound healing
extrafascial: partial/complete seperation of outer layers of sutured wound/underlying fascial layer remains intact
fascial: evisceration, seperation of fascial layers
s/s of impending wound disruption
signs of infection
absence of healing ridge by 5th - 9th postoperative day
seroma or hematoma formation
increase in serous discharge
chronic nonhealing wounds
do not proceed thru healing process
progress thru healing process but cannot maintain structural & FXtional integrity
arrest in inflammatory phase
harbor bacteria
increased levels of inflammatory mediators, chronic inflamm, necrosis, fibrosis
pressure injuries
localized ischemic lesions of skin & underlying tissue
over bony prominence
external pressure impairs flow of blood & lymph
risk factors pressure injuries
immobility reactive hyperemia microthrombi shearing forces poor perfusion (PAD, DM) skin status/maceration
pressure injuries s/s
pressure decreases gradually from bony area toward periphery
discoloration to blisters or areas of denuded superficial skin to deep tissue damage w/ necrosis
pressure injuries DX/TX
DX: regular assessment, WBC, erythrocyte sedimentation rate TX: surgical debridement autolytic debridement skin grafting topical/systemic ABX hydrocolloid/transparent film dressing alginate, foam, iodine dressings can lead to osteomyelitis
pressure ulcer staging
Stage 1: sores are not open wounds. Painful, but no breaks or tears, reddened and does not blanch
Stage 2: skin breaks open, wears away, or forms an ulcer, which is usually tender and painful. The sore expands into deeper layers of the skin. It can look like a scrape (abrasion), blister, or a shallow crater in the skin.
Stage 3: forms a small crater. Fat may show in the sore, but not muscle, tendon, or bone.
Stage 4: muscle and bone potentially tendons and joints
