Module 3- Wound healing

How long is the inflammatory stage?

0-6 days

which is smaller 3-0 or 10-0?

10-0

When is surgical glue or tape used?

laparoscopic surgery

What does fibrin do?

makes clot

What process is epithelialization?

mitosis wound edges grow in

What is catgut (chromic)?

a type of suture made of bovine intestine - used in the gut - reabsorbable

What are adhesions?

bands of scar tissue that form between or around organs

-Minor sterile breaks -Entrance into GI, GU or Resp w/o significant spillage -Almost always can be closed primarily A. Clean B. Clean-contaminated C. contaminated D. dirty

B. Clean-contaminated

What would a SBO surgery with a small knick of the bowel be classified? A. clean B. clean contaminated C. contaminated D. Dirty

B. clean contaminated

Which stage is (21 days - 24 months) -Collagen fibers reorganize, remodel, mature and gain tensile strength A. Inflammatory B. proliferative C. Maturation

C. Maturation Collagen maturation Wound contraction

Which stage is (4 - 24 days) -Granulation tissues generated - characterized by: beefy, shiny tissue with granular appearance -Wound contracts decreasing surface area -Epithelial cells seals the wound margins creating scar/scab A. Inflammatory B. proliferative C. Maturation

B. proliferative Fibroplasia and Matrix synthesis Angiogenesis within granular tissue Wound contraction Epithelialization

-Wound is left open, debrided multiple times -Formation of granulation tissue, new blood vessels, fibroblasts, inflammatory cells) -Most infected wounds heal this way What is this type of healing? A. primary intention B. secondary intention C. delayed primary D. delayed secondary

B. secondary intention

-Spillage of GI, GU or Respiratory contents -Traumatic wounds -Can often still be closed primarily with adequate debridement/lavage intra-op, and proper wound care -May opt for delayed closure A. Clean B. Clean-contaminated C. contaminated D. dirty

C. contaminated

What would a stab wound surgery be classified? A. clean B. clean contaminated C. contaminated D. Dirty

C. contaminated

-Wounds with extensive propensity for infection -Heal open under a carefully maintained dressing for about 5 days, then closed; Can be closed with sutures/staples, or skin graft -Less likely to become infected because their oxygen needs are better met (capillary formation) What is this type of healing? A. primary intention B. secondary intention C. delayed primary D. delayed secondary

C. delayed primary

T/F a 3-0 suture is smaller than a 4-0?

False; 3-0 is larger and thicker than 4-0

How does wound contraction occur?

Fibroblasts attach to collagen and pull it together Contraction is beneficial on back or neck but may be disfiguring on face or disabling around joints

What does granulation tissue contain?

Plump fibroblasts, collagen, blood vessels and inflammatory cells

What is primary healing vs. secondary healing?

Primary wound healing occurs after a surgical incision in which the edges of the wound are connected usually by suture. Tissue is cleanly incised & reapproximated. In general, such wounds will heal within 6 - 8 days Secondary healing -Wound is left open, debrided multiple times -Formation of granulation tissue, new blood vessels, fibroblasts, inflammatory cells) -Most infected wounds heal this way

What is the is one of the most important and modifiable factors for wound dehiscence?

Proper wound closure

What is fibroplasia?

Replication of fibroblasts stimulated by multiple cytokines and growth factors Fibroblasts found mostly at wound edges with oxygen tension of about 40 mm Hg (optimal)

T/F Collagen deposition is rate limited by PaO2

True

What are retention sutures?

a reinforcing suture made of exceptionally strong material such as wire, and including large amounts of tissue in each stitch

What does thrombin do?

converts fibrinogen to fibrin

Which skin layer is the strength layer, and failure to accurately approximate this layer leads to increased wound disruption?

fasica

Best closure for small wound is __________

fine interrupted sutures, loosely placed close to wound edge

What is a lavage?

flushing of a wound to remove foreign material, wound exudate and contamination washing out of a body cavity, such as the colon or stomach, with water or a medicated solution.

When are prolene sutures used?

general soft tissue approximating and/or ligation, including use in cardiovascular, ophthalmic procedures, and neurological procedures Ex. coronary vessels

What type of tissue is formed during secondary healing?

granulation tissue

Wounds in well vascularized areas heal rapidly; give an example of a well vascularized area and a low vascularized area

highly vascular: intestines low vascular: foot

Why is oxygen perfusion so important for wound healing?

oxygen needed for mitosis in epithelialization, angiogenesis, and collagen deposition

What does healthy granulation tissue look like?

pink to red "beefy" due to new capillary formation, is soft to the touch, moist appears "bumpy," can be shiny and typically painless Unhealthy granulation tissue is darker red, bleeds easily with minimal contact, painful, and maybe covered by shiny white or yellow fibrous tissue that is avascular, impeding healing

What is the most frequent cause wound healing failure?

poor perfusion and oxygenation

What does granulation tissue look like?

red, moist tissue composed of new blood vessels, the presence of which indicates progression toward healing

Where do new capillaries come from during angiogenesis?

sprout from preexisting venules Grow toward the injury in response to chemoattractants released by platelets & macrophages Epithelial cells respond to similar stimuli (growth factors) as fibroblasts

What is the inflammatory stage of wound healing?

(0-6 days) -Characterized by edema, erythema, heat, pain -Bleeding is controlled by hemostasis -Bacterial growth controlled by leukocytes (PMN)

What is the maturation stage of wound healing?

(21 days - 24 months) The last stage of wound healing involves apoptosis and the production of new cells. The apoptosis and degradation of the extracellular matrix and immature type III collagen and the ultimate formation of mature type I collagen are critical to scar formation, integrity, and strength. -Collagen fibers reorganize, remodel, mature and gain tensile strength. If there are errors during this phase, there may be excessive wound healing leading to hypertrophic or keloidal scarring or a chronic wound resulting in persistent granulation tissue.

What is the proliferative stage of wound healing?

(4 - 24 days) - Granulation tissues generated - characterized by: beefy, shiny tissue with granular appearance -Wound contracts decreasing surface area -Epithelial cells seals the wound margins creating scar/scab

What is negative pressure wound therapy?

(Aka vacuum-assisted wound closure) Stimulates closure of wound, creates moist environment favorable for granulation tissue

Name ten factors that delay wound healing

1. diabetes 2. inadequate blood volume/perfusion 3. malnutrition 5. cancer/malignancy 6. radiation therapy 7. smoking 8. anemia 9. edema 10. dehydration

What processes in wound healing is oxygen needed for? Choose all that apply 1. inflammation 2. bactericidal activity 3. angiogenesis 4. epitheliazation 5. collagen deposition

1. inflammation 2. bactericidal activity 3. angiogenesis 4. epitheliazation 5. collagen deposition ALL

Name the three stages of wound healing in order and on average how long is each stage?

1. inflammatory stage (0-6 days) 2. proliferative stage (4 - 24 days) 3. maturation stage (21 days - 24 months)

What are the most common areas for decubitus ulcer?

1. sacrum 2. heel 3. head 4. hips areas of high pressure on areas when you are laying down

When does angiogenesis begin?

2 days after injury & becomes visible by the 4th day

How long is the maturation stage?

21 days to 24 months

Which stage is (0 - 6 days) -Characterized by edema, erythema, heat, pain -Bleeding is controlled by hemostasis -Bacterial growth controlled by leukocytes (PMN) A. Inflammatory B. proliferative C. Maturation

A. Inflammatory

Monofilament sutures don't harbor bacteria, whereas polyfilament sutures may harbor bacteria. Which of the following are monofilament? A. Nylon B. Prolene C. Ethlion D. Dacron

A. Nylon B. Prolene monofilament

-Tissue is cleanly incised & reapproximated -Repair occurs without complication -Usually closed with sutures; What is this type of healing? A. primary intention B. secondary intention C. delayed primary D. delayed secondary

A. primary intention

What are coagulation products?

fibrin, thrombin

What are surgical staples made of?

steel alloys

Why do you have to "set" bones?

New bone remodels but can't correct deformities of angulation or rotation

Name three Synthetic Absorbable Sutures

- Vicryl - Monocryl - PDS V = V in urology and gyn Mono = kissing --> GI PDS sounds like PDA Useful in GI, urologic and Gyn

ideal suture is ___________, ____________, ___________ and ______________

- flexible - strong - easily tired - securely knotted

What lowers wound PaO2?

- hypovolemia - stress - cold - fear - catecholamines

What could cause increased wound inflammation?

- infection - foreign body - excessive lytic molecules

What are some factors that could inhibit inflammatory response?

- steriods - immunocompromised pt ( DM, CKD) - immune suppresents - chemo Initial stages of healing more affected

What can raise oxygen perfusion?

- supplemental O2 - Hyperbarics

Which sutures are good for skin, fascia and vasculatuture?

- synthetic non-absorbable suture -Doesn't handle as well as silk & needs multiple knots - examples: nylon, prolene, dacron and ethilon "NYLON or PROLENE ERIC DU"

What determines the material of suture you use?

- where the surgery is - if you want it to be absorbable or not

What are examples of synthetic absorbable sutures?

-Vicryl, Monocryl, PDS -Useful in GI, urologic and Gyn

Name the 7 mechanisms of wound healing after acute injury in sequential order:

1. Coagulation and Inflammation 2. Fibroplasia and Matrix synthesis 3. Angiogenesis 4. Epithelialization 5. Collagen maturization 6. Wound contraction

How long is the proliferative phase?

4- 24 days

Fibroblasts found mostly at wound edges with oxygen tension of about _____ mm Hg (optimal)

40

-Atraumatic, sterile conditions -No entry into GI, GU or Respiratory tracts -Primary closure A. Clean B. Clean-contaminated C. contaminated D. Dirty

A. Clean

Describe the processes that happen during the coagulation and inflammation stage that happens after acute energy

Coagulation: During this stage of wound healing, the blood vessels at the site of injury contract, and the blood that leaked out through the wounds begin to coagulate and scab over. The coagulation process results from the aggregation of thrombocytes, forming a fibrin network. The fibrin network is the basis for a clot and serves as a temporary matrix for migrating cells. The thrombocytes release cytokines and growth factors that serve as pro-inflammatory signals to attract the immune response to the site of the wound. Inflammatory: Inflammatory components (Interleukins, histamine, etc.) initially cause vasoconstriction First to the site: neutrophils Later cause dilatation so that blood plasma & leukocytes can move freely into the wound Monocytes arrive at the site of injury within two days, where they differentiate into macrophages. Macrophages come to dominate in wound Macrophages recruit fibroblasts and endothelial cells that mark the next stage of healing. Release large amount of Lactate that stimulates production of growth factors, leads to remaining steps

-Existing infection within tissues (e.g. abscess) -Delayed or Secondary closure -Frequent cleaning and debridement of wound post-op A. Clean B. Clean-contaminated C. contaminated D. dirty

D. dirty

When are ethioline sutures used?

For deep or irregular lacerations, or lacerations on hands, feet, and skin over joints, monofilament nonabsorbable suture, such as nylon (Ethilon) or polypropylene (Prolene)

What is the first thing that happen at the site of a wound or an acute injury?

Hemostasis (coagulation) and inflammation; Coagulation and Inflammation can happen simultaneously Blood vessels constrict (Interleukins, histamine) and clotting factors (fibrin and thrombin and complements) are activated Clot formation blocks the bleeding and acts as a barrier to prevent bacterial contamination Same cellular and molecular elements that signal hemostasis also signal tissue repair Thrombin activates platelets, which then attract leukocytes (esp. macrophages) & fibroblasts: alert various cells to start the repair process at the wound location - fibrin plug for primary healing - fibrin clot for secondary healing

What is callus formation and where does it happen?

callus is specialized granulation tissue in bones replaces hematoma and then calcifies into bone; New bone then remodels

What are fibroblasts?

cells that secrete fibrous proteins like elastin and collagen they function to synthesize the extracellular matrix

Fibroblasts secrete _______ and _________ to form a matrix of connective tissue

collagen and proteoglycans Holds wound edges together and embed cells

What is delayed primary closure?

delayed closure secondary to contamination or risk of infection -Heal open under a carefully maintained dressing for about 5 days, then closed -Less likely to become infected because their oxygen needs are better met (capillary formation)

What is granulation tissue?

immature connective tissue with microscopic blood vessels has three main functions: Immune: Protects the wound surface from microbial invasion and further injury. Proliferative: Fills the wound from its base with new tissue and vasculature. Temporary plug: Replaces necrotic tissue until replacement by scar tissue The granulation tissue itself is made up of extracellular matrix, proteoglycans, hyaluronic acid, collagen, and elastin

What are some tx for keloids?

intra-lesional steroid injections, Silastic sheets (increase lytic activity in scar)

What is monocryl used for?

subcutaneous

When are vicryl sutures used?

synthetic absorbable It is indicated for use in general soft tissue approximation and/or ligation, including ophthalmic procedures, but not cardiovascular or neurological tissues not ideal for skin lacerations

What is anastomosis?

where the vein and artery are connected

What long does it take primary wounds to heal?

within 6 - 8 days