Wound Care Flashcards
Which cell is highest in number in a healing wound after 5 days?
a) neutrophils
b) macrophages
c) keratinocytes
d) fibroblasts
b) macrophages
neutrophils within 24 hour
How many hours does early inflammation last for?
24 hours
How many hours does late inflammation last for?
48 hours
How many hours does proliferation last for?
72 hours
How long does the remodelling phase last?
Weeks to months
When is maximal collagen content first achieved in normal primary wound healing?
a) 3 weeks
b) 6 weeks
c) 12 weeks
d) 6 months
3 weeks
What percentage of maximal skin strength is achieved by 6 weeks?
a) 30%
b) 50%
c) 70%
d) 90%
70%
skin and scar never as strong as original dermis
Name 7 Local factors affecting wound healing
- infection
- tension
- hematoma
- vascular supply
- edema
- foreign body
- neuropathy
Name 8 SYSTEMIC factors affecting wound healing
- Steroids
- Nutrition
- Anemia
- Immunosuppression
- Diabetes
- Renal/Hepatic Failure
- Radiation
- Smoking
Which of the following is the mechanism of steroid inhibition in wound healing?
a) increase angiogenesis
b) inhibit synthesis of pro-collagen
c) increased collagenase activity
d) increased macrophage production
Inhibits synthesis of pro-collagen
Systemic corticosteroids interfere with wound healing. There effect may be minimized by:
a) Vitamin A
b) Vitamin C
c) Vitamin E
d) Zinc
Vitamin A (25 000 IU per day)
In collagen synthesis, which two residues must be hydroxylated
for stability?
Proline and Lysine
What is the sequence of Collagen synthesis?
mRNA –> pre-procollagen –> hydroxylation (pro, lys) –> Procollagen Trimers –> excretion & cross linking (lysine & hydroxylysine)
Which vitamin is important in collagen synthesis/stability
Vitamin C (ascorbic acid)
Name the effect of nutritional protein deficiency
Immune response and poor collagen formation
Name the effect of nutritional Vtitamin C deficiency
- Inhibits secretion of collagen by fibroblasts
- Required co-factor for hydroxylation and cross-linking for collagen synthesis
Name the effect of nutritional VITAMIN A deficiency
Impairs epithelial proliferation and differentiation
Name the effect of nutritional ZINC deficiency
Impairs function of enzymes, eg nucleic acid polymerases
What are the 3 types of wound healing?
Primary intention Secondary intention (prolonged inflammatory phase) Tertiary intention (delayed primary)
Scar maturation process may last how long?
3 weeks to 2 years
In scan maturation, which type of collagen is replaced by another?
Type 3 collagen replaced with Type 1 (1:8)
What happens to vascularity during scar maturation?
Decreased vascularity
What percent of hospitalized patients in Canada have pressure ulcers (PU)?
9 and 25%
What kind of ulcer is responsible for more hospital admissions than any other complication of diabetes?
DM foot ulcers
At the TOH (The Ottawa Hospital), what is the frequency of all stages of PU? Stage 2 and up?
All stages = 14.3%
Stage 2 and up = 9.9%
What are the 3 concepts of wound healing?
1) moist wound healing
2) acute vs chronic wound healing
3) wound bed prep
What is the advantage of moist wound healing vs air dry?
Accelerates healing by 50% due to faster migration of epithelial cells.
(epithelial cells migrate on moist wound bed, instead of under a dry scab)
Name 3 other advantages to moist wound healing
- allows autolytic debridement
- decreases pain
- wet to dry dressings peel off healing layers
Define acute wound healing
Wound that
- passes in an orderly fashion through the phases of healing
- closes in a predictable time frame
Define chronic wound healing
Wound that are
- present for >3 months
- fails to progress through the 4 phases of wound healing
In chronic wound healing, wounds are often stuck in which phase?
Phase 2 - Inflammatory phase
What molecular processes predominate in a chronic wound?
- WBC predominate and release MMP
- MMP digest wound matrix faster than it can be laid down
- Leaky capillaries (excess release of proteins that inactivate GF)
- Fibroblasts stop responding to normal wound healing signals
What contributes to the vicious cycle of chronic wound healing?
Continued release of MMP by stimulated WBC by local wound environment
- bacteria
- necrotic tissue
What is the goal of wound bed prep?
Convert a chronic wound into an acute wound (allow normal healing)
List the three pronged attack of a wound bed prep
- Debridement
- Decrease Bacterial Burden
- Manage wound exudate
Name 4 methods of wound debridement
- surgical
- enzymatic
- biological
- lavage
2 goals of debridement
- remove necrotic/infected tissue
2. allow proper wound staging
Name 3 possible microbial states of a wound
Contamination (non-replicating organisms)
Colonization (presence of replicating organisms, no host imm response)
Infection (replicating organisms WITH host immune response)
What formula depicts the presence of an infection?
Presence of Infection
= (#bacteria x virulence of bacteria)/host immune function
What are subtle signs of wound infection?
Increased pain
Friable granulation tissue
Increased exudate
Wound deteriorates
What is the wound “macro” environment?
Micro wound environment?
Treating the patient
Treating the wound
Underlying cause for the Macro Environment, and its management
Arterial (bypass, amputate, angioplasty)
Venous (compression dressing, Sgx)
Diabetic (offload pressure, anti-diabetic meds)
Infection (Abx, debride)
Pressure (offload pressure, mattress, MYOcutaneous flap)
How do you manage the Micro wound environment?
D.I.M.E
D - Debridement
I - Infection/inflammation
M - Moisture Balance
E - Edges of the wound
What are the 3 rules of dressing selection?
1-No universal wound dressing
2-Must be appropriate for underlying cause
3-Re-assess dressing regularly, as process is dynamic and changes
Mechanism of Action of Silver in dressings?
(Ionized silver)
Targets bacterial DNA
Disrupts proteins in cell membrane
Inhibits function of some bacterial enzyme
What two dressings decrease bacterial load? (HOT)
Silver (acticoat) - bactericidal + broad spec MRSA/VRE
Iodosorb - broad spec, decreased foul odor
Which dressings are Not recommended for decreased bacterial burden?
Iodine solutions Hygeol Acetic acid Topical abx Peroxide
What does Hydrogel do?
Moist wound healing (low exudate)
Autolysis
Decreases pain (when peeled off)
NOT recommended (wet to dry saline soaked gauze)
For moderate to heavy exudate wounds, what is recommended?
Foam
Alginate
Hydrofiber
The VAC (negative pressure dressing)
NOT abdo pads
Name the 4 wonders of wound care
VAC
Growth factors
Hyperbaric Oxygen chamber
Soft Tissue Substitutes
How does the VAC work? (7 items)
Improves blood flow Granulation Tissue formation Reduces edema Decreases Bacteria Controls exudate Mechanically draws wound edges inward Moist environment
Name indications for hyperbaric oxygen
Gas Gangrene, Compartment Syndrome, Nec Fasc
Refractory osteomyelitis, Skin Grafts/Flaps, Diabetic ulcers
Define hyperbaric oxygen
Breathing 100% oxygen at increased atmospheric pressures
How does HBO2 work?
1 Hyperoxygenation 2 Vasoconstriction 3 Angiogenesis 4 Fibroblast proliferation and collagen synthesis 5 Leukocyte oxidative killing 6 Toxin Inhibition (clostridium) 7 Antibiotic Synergy
Which of the following statements is true regarding Osteogenesis Imperfecta?
1) Due to Mutation in Collagen Type 1
2) Due to defect in Elastin
3) Causes abnormal adhesion of the epidermis to basement membrane
4) Cases abnormal wound healing and skin elasticity
Mutation is Collagen Type 1
Name the 4 types of OI
I- mild (AD)
II - extremely severe (AR)
III - Severe (AR)
IV - Undefined (AD)
Define Cutis Laxa (Elastolysis)
Skin laxity
Fibulin or Elastin gene substitution
Degenerative changes in skin Elastin
?Increased elastase activity
Define Epidermolysis Bullosa
Epidermins and dermis separate
Blistering/Skin erosion
Keratin/Collagen VII/Laminin
Which 3 proteins are implicated in epidermolysis Bullosa?
Keratin
Collagen VII
Laminin
Which of the following statements is/are true regarding Ehlers Danlos?
a) due to mutation in collagen
b) due to a defect in fibrillin
c) causes increased joint elasticity
d) causes abnormal wound healing and skin elasticity
a) due to mutation in collagen
Ehlers Danlos can have abnormalities in which types of collagen?
I, III, V
Which gene/protein is abnormal in Marfan Syndrome?
FBN1 gene = fibrillin protein
List 3 features of marfan syndrome
Tall stature
Arachnodactyly (long and slim spider fingers)
MV prolapse, Aortic Regurg
What are 2 possible wound healing complications?
Hypertrophic scarring
Scar contracture
21M suffers a 8x10 cm partial thickness wound to Lt flank. After 2 weeks is has shrunk by 25%. Cells most responsible for this are?
a) neutrophils
b) macrophages
c) fibroblasts
d) myofibroblasts
myofibroblasts
In which of the following ways do hypertrophic scars differ from normal scars?
a) increased ratio of Type 1 collagen to Type 3 collagen
b) increased water content
c) increased collagen concentration
d) decreased glycosaminoglycan content
c) increased collagen concentration
In fact Collagen type 3 is increased, so is collagenase Normal Skin (I:III) 8:1 Hypertrophic scar 8:4
Which of the following is UNTRUE about keloids?
a) histologically similar to hypertrophic scars
b) extend beyond the limits of the original wound
c) usually amenable to surgical excision
d) can be treated with steroid injection
e) radiation is mentioned only to be condemned
UNTRUE answer- generally amenable to surgical excision
Name 5 risk factors for keloid/hypertrophic scars
- Location (#1 ear, shoulder, midline scars)
- Genetics (dark skin)
- Race
- Age 10-30
- Delayed wound healing
How can you manage hypertrophic scars?
Time, Pressure, Silicone Gel, Steroids
Keloid scar management?
Same as hypertrophic scars, but also includes -radiation -Imiquimod (aldera) -Retinoic acid ?Excision
What are the 4 stages of Wound healing?
(C-I-P-R) Coagulation Inflammation Proliferation Remodelling
What are the stages of wound healing?
CIPR
- coagulation
- inflammation
- proliferation
- remodelling
How do steroids act in the setting of wound healing?
Inhibit
- macrophage function
- fibrogenesis
- angiogenesis
What is one bacteria that acetic acid works to eradicate?
Pseudomonas
Greenish/yellow discharge from wound
Name 4 VAC Tips
- black/white sponge does not have to touch wound edges (or sit right on regular skin)
- dry and tape wet edges last
- start suction even before completely sealed
- you can never have too much tegaderm
For normal wound healing, what 3 things do you advise patients to prevent a bad scar (after stitches are out)?
1) No tanning in the early phase
2) Pressure (scar massage)
3) Silicone gel/sheets
Risks of injecting steroids (kenalog) into a scar?
De-pigmentation Fat atrophy (dent in skin)
