Integument Flashcards
Phases of wound healing?
Inflammatory phase Proliferative phase Maturation and remodeling phase
What is required for optimum collagen production?
vitamin C
scars retain what % of tensile strength of normal skin
70-80%
Phases of wound healing
InflammatoryProliferativeMaturation/remodeling
Inflammatory phase of wound healing
Last up to 5 days, hemostasis, coagulation, MMPs, serine proteases, leukocyte margination, macrophages start to move in
Proliferative phase of wound healing
5-20 days, granulation tissue forms4 processes: neovascularization/angiogenesis, fibroplasia (MMP 1,2,3 facilitate migration of fibroblast which secrete fibronectin forming loose ECM) and collagen deposition (type 3 laid first which is weak baby collagen and slowly replaced with strong type 1 collagen), epithelialization (guided by type 1 collagen), wound contraction (skin peripheral to a full thickness defect advances in a centripedal fashion toward the center of the wound)
Maturation/remodeling
type 1 collagen replaces type 3, takes from day 20 to one year
Wound contraction rate
0.6-0.75 mm /day
What is contracture?
loss or inhibition of motion or function as a result of excessive scar tissue or muscle atrophy or fibrosis
What is required for optimum collagen production
vitamin C
When does tensile strength increase rapidly?
after day 4-5 at which fibroplasia and early collagen deposition noted
What do fibroblasts make?
collagen
What is intussceptive growth?
process of epithelial proliferation and collagen deposition that occurs within the stretched skin to bolster and restore cutaneous areas that are under significant tension
How long does wound contraction take?
6 weeks, square and rectangular incisions contract more effectively than circular ones
3 weeks after injury, what is the tensile strength of scar?
20% of final strength
Scars retain what % of tensile strength of normal skin?
70-80%
Formation of granulation tissue in cats vs. dogs
cats 19 days, dogs 7.5 days
How are wounds classified according to degree of contamination? List and describe.
Clean- atrumatic, surgically created under aseptic conditions
Clean contaminated- minor break in aseptic surgical technique, contamination is minimal and easily removed
Contaminated- recent wound related to trauma with bacterial contamination from street, soil or oral cavity; surgical wound with major break in asepsis
Dirty/infected- older wound with exudate or obvious infection
What are the 3 grades of open fractures?
Grade I- small break in skin caused by bone penetrating through
Grade II- soft tissue trauma contiguous with the fracture, often caused by external trauma
Grade III- extensive soft tissue injury, commonly in addition to a higher degree of comminution of the bone
which type of lavage solution, compared to the others, was shown to have more mild cytotoxic effects on fibroblasts, hence making it a preferred flushing solution?
LRS
what concentration of chlorhexadine is recommended for lavaging wounds?
0.05%
Benefits of using sugar in open wound? Drawback?
osmotic action causing bactericidal effect; draws macrophages to wound, accelerates sloughing of devitalized tissue, cheap
Drawback- cuases more effusion, tus requiring more frequent bandage changes
Advantages of honey as a wound dressing?
decreases edema, accelerates sloughing of necrotic tissue, provides rich cellular energy source, antibacterial properties b/c of high osmolarity, acidity and H2O2 content
list 4 types of wounds that do not typically require the need for antibiotics
Clean wounds
superficial wounds <6 hrs old
contaminated wound that can be converted to clean wound with primary closure
wounds with a healthy granulation bed
Describe how to estimate surface area affected by burn wounds
head/neck=9%
each forelimb=9%
each rear limb=18%
dorsal trunk=18%
ventral trunk=18%
how do you characterize a 1st degree burn?
superficial; epidermis only
characteristics of 2nd degree burn?
epidermis and superficial or deep part of dermis affected
characteristics of 3rd degree burn?
full thickness, affecting entire epidermis and dermis
characteristics of 4th degree burn?
full thickness with extension to muscle/tendon/bone
what percent BSA affected has been shown to have a poor prognosis with burns?
>50%
recommended fluid rate during the first 24 hrs in burn patients?
4 ml/kg BW x % total body surface area affected
with 50% given over the first 8 hours.
reduction of 25%-50% in cats
*Severe burn injury, burn shock and smoke inhalation injury in small animals. Part 2. Vaughn et al. JVECC 2012
At what time point after a burn does the patient’s fluid status often stabilize, making them at higher risk for overload and edema?
48 hrs
T/F- in human burn injury, prompt removal of the burn eschar is correlated with improved survival?
true
Characteristics of Burn Shock
Intravascular volume depletion
reduced CO
increased systemic vascular resistance
resulting in decreased peripheral blood flow
