Exam 1 Flashcards
What are the phases of wound healing?
- Inflammatory phase: 1-10 days
- Proliferative phase: 3-20 days
- Remodeling phase: 9 days - 2 years
Fibroblasts
cells from which connective tissue is derived
Fibrocytes
mature fibroblasts; responsible for regulating the tissue
Myofibroblasts
responsible for contracting and approximating the wound edges
Mast Cells
responsible for releasing histamine which causes dilation
What do platelets release?
serotonin
What are the three fibrous elements of connective tissue?
collagen, elastin, and reticulin
Ground Substance
a clear and viscous substance that surrounds cells and fibers; consistency depends on external factors applied to the wound
What are the individual steps of the inflammatory phase of wound healing?
- vasoconstriction
- vasodilation
- edema
- necrosis
- Blood cells are brought to the wound (macrophages, erythrocytes, leukocytes, platelets, and plasma protein)
- lymphocyte and lymph node activity
What are the individual steps of the proliferative phase of wound healing?
- Fibroplasia
- Granulation/angiogenesis
- Revascularization
- Wound closure
Endothelial cells
responsible for generating new blood vessels
Epithelial cells
responsible for generating new skin tissue
Fibroblasts follow:
macrophages
Myofibroblasts attract:
endothelial cells
What is essential to wound healing?
revascularization of healthy granulation tissue
Primary Intention
surgeon closes wound by bringing edges together; held together by stitches, staples, glue, etc.
Secondary Intention
wound closes by contraction or re-epithelialization
Tertiary Intention (delayed primary)
a wound that is healing by secondary intention but is then closed by a surgeon
Dehiscence
a wound that is closed by primary intention but later opens as a result of infection or maceration
Contraction
typically involves chronic wounds and doesn’t require granulation tissue; peri-wound tissue moves toward the center of the wound as myofibroblasts are activated by chemical mediators and begin to contract to approximate the wound edges
deeper wounds are more likely to close by contraction
Re-epithelialization
can only occur over healthy granulation tissue; begins within hours of wounding, but the wound must be clean, moist, and granulated
What can prevent re-epithelialization?
- presence of eschar
- dry environment
- chemicals/toxicity
- inappropriate cellular messaging
What are the 4 steps of re-epithelialization?
- mobilization
- migration
- proliferation
- differentiation
Contact inhibition
signals the end of migration/proliferation when the edges of the wound contact one another
T/F: Wound closing signifies wound healing?
False
Once healed, a wound is approximately __ of its original strength
80%
What are two potential remodeling errors?
hypertrophic scarring and keloid scarring
Hypertrophic scarring
excess collagen formation, defined to wound borders
Keloid scarring
excess collagen formation, not defined to wound borders
What is the #1 reason for wound non-healing?
infection
What is the only way to tell if a wound is infected?
tissue culture through a punch biopsy
Biofilm
complex communities of bacteria that adhere to solid surfaces; 60% of chronic wounds, 6% of acute wounds
signifies need for more aggressive treatment
What are reasons for wound non-healing?
- infection
- inefficient cellular activity, decreased collagen metabolism
- decreased oxygen availability
- increased rate of cellular necrosis
- wound sepsis (septicemia)
- osteomyelitis
- gangrene
- poor nutritional status of the wound
- medications/chemical inhibitors
What are the age-related changes that occur in the epidermis?
stratum corneum becomes dryer and rete pegs become fewer; predisposes the epidermis to shear injuries
What are the age-related changes that occur in the dermis?
decreased collagen production resulting in decreased elasticity; decreased pain receptors and decreased vascularity
What is the effect of radiation on wound healing?
destroys the cells responsible for wound healing
What is the effect of chemotherapy on wound healing?
slows the healing process
What are abnormal processes of wound healing?
hypergranulation - tissue forms but is not signaled to stop
hypogranulation - wound bed is under-granulated and pale; may be d/t necrosis or infection
What are the environmental factors affecting wound healing?
- choice of dressings
- use of topical agents, misuse of cytotoxic agents
- incontinence
- smoking, alcohol, recreational drugs, poor diet
What are the iatrogenic factors affecting wound healing?
- risk of infection
- handling of dressings
- choice of cleansing method
- repeated or unprotected pressure
Angiogenesis
process of endothelial cells forming new capillaries; new capillaries perfuse the collagen matrix, which provides a base for epithelial cell migration
What are causes of wounds (from most common to least common)?
- pressure
- venous insufficiency
- arterial insufficiency
- neuropathy
- trauma
- malignancy
- CT disorders
- thermal injury
How long until damage to the superficial occurs?
2-6 hours
How long until damage to the deep muscle and fascia occurs?
2 hours or less
Slough
necrotic tissue that is in the process of separating from the wound; stringy, loose, waste products of inflammation
Eschar
a slough, dead tissue: thick coagulated crust or slough which develops following a thermal burn, chemical or physical cauterization of the skin, or any wound
What are the MOST common sites of pressure ulcers?
- sacrum
- coccyx
- ischial tuberosity
- trochanter
- lateral malleolus
- calcaneus
account for approximately 95% of al pressure injuries
What are the stages of pressure injury?
Stage 1: non-blanchable erythema of intact skin
Stage 2: partial-thickness skin loss with exposed dermis
Stage 3: full-thickness skin loss
Stage 4: full-thickness skin and tissue loss
Unstageable Pressure Injury
obscured full-thickness skin and tissue loss: full skin and tissue loss in which the extent of tissue damage within the ulcer cannot be confirmed because it is obscured by slough or eschar
T/F: A wound can be staged when slough or eschar is present?
False. The slough or eschar must first be removed before staging can occur.
What percentage of leg ulcers result from venous insufficiency?
80%; the remaining 20% is a result of arterial insufficiency
Etiology of Venous Leg Ulcers
the percentage of blood in the veins increases as a result of incompetent valves, congenital absence, and/or inactivity; decreased fibrinolysis occurs, resulting in soft tissue becoming more fibrous; fibrinogen leaks into surrounding tissue; decreased metabolism in the dermis results in cell death; trauma occurs resulting in venous leg ulcer
Hemosiderin Staining
brownish, purple appearance of the skin signifying the breakdown of hemoglobin and resulting in permanent pigment changes; precursor to potential skin injuries
Characteristics of Venous Leg Ulcers
usually preceded by hemosiderin staining; accompanied by liposclerosis and edema, but is not painful; involves drainage
most venous leg ulcers occur proximal to the medial malleolus and are irregular in shape
Etiology of Arterial Leg Ulcers
involves a lack of blood flow: arterial occlusive disease/ arteriosclerosis/PVD; plaque forms in the artery and blood flow is obstructed when the lumen size has decreased by 75%
Symptoms of Arterial Disease
- skin is cold on palpation
- pain: ischemic calf pain/intermittent claudication, resting or night pain
- decreased sensation
- edema is rare
- absent or decreased pulses
- toenail deformities
- decreased hair growth
- atrophy of skin, muscle, subcutaneous tissue
- pallor and/or dependent rubor
- ischemia with tissue necrosis
Characteristics of Arterial Leg Ulcers
- necrotic, pale
- lack granulation tissue
- well-defined border
- painful
- dry, limited, or no inflammatory response
- common sites occur on the toes, dorsum of the foot, or lateral malleolus
What are important considerations when examining a wound?
- wound history: when, how, duration
- previous treatment
- co-morbidities
- environment
- pain assessment
Red-Yellow-Black Classification System
- red: well-granulated and in need of protection
- yellow: covered with collagenous and fibrinous slough
- black: covered with eschar, a thick, dry, leathery necrotic tissue
What are important questions to ask concerning erythema or maceration around a wound?
- Is it part of the inflammation process?
- Is it an indication of a deeper wound?
- Does it represent infection?
- Is it impacting the healing process?
Bioburden
the quantity of bacteria in the wound; >10^5 organisms/gram of tissue signifies a clinical infection
What are the guidelines for skin temperature regarding blood flow?
below 92-96˚F on the torso and 80˚F in the extremities indicates limited blood flow to the skin
Serum Albumin
≥3.5 mg/dl may indicate risk of infection and possible death
Lymphocyte Count
≥1,800 mm3 may indicate risk of infection
What are the potential tests for assessing the venous component of a vascular examination?
- venous doppler
- percussion test
- trendelenberg test
What are the potential tests for assessing the arterial component of a vascular examination?
- arterial doppler
- pulses: posterior tibialis, dorsalis pedis, femoral, & popliteal
- rubor of dependency
- venous filling time
- claudication time
What are the three risk assessment tools covered in lecture?
- Braden Scale
- Norton Scale
- PUSH Tool
Treatment should be altered every ___ days is there is no change in the wound
3-7 days
What are the RATS of malpractice claims?
- Records
- Attitudes
- Training
- Standards of Practice
What are potential problems with documentation?
- alterations
- blame
- conflicting information
- illegibility
- unapproved abbreviations
- gaps and omissions
- inconsistencies with required practice standards
What are the six categories on the Braden Scale for Predicting Pressure Sore Risk
- sensory perception
- moisture
- activity
- mobility
- nutrition
- friction and shear
*items are scored 1-4; lower total scores signify at-risk patients, while higher total scores signify normal
What are the three categories on the Pressure Ulcer Scale for Healing?
- length x width: scored 0-10
- exudate amount: scored 0-3
- tissue type: scored 0-4
*wounds with lower scores are likely to heal, while wounds with higher scores are unlikely to heal
