exam 1 Flashcards

Question

monocytes in debridgement phase

Answer 1

▪Essential for wound healing** ▪ Neutrophils are not ▪Major secretory cells ▪ Synthesize growth factors for tissue formation and remodeling ▪Become macrophages in wounds ▪ 24-48 hours *Secrete collagenases ▪ Remove necrotic tissue, bacteria, foreign material ▪Secrete chemotactic and growth factors ▪Recruit mesenchymal cells ▪Stimulate angiogenesis ▪Modulate matrix production

Answer 2

▪Transforming growth factor to produce fibronectic ▪ Cell binding and fibroblast movement** to injury ▪Platelet-derived growth factor and basic fibroblast growth factor ▪Originate from undifferentiated mesenchymal cells ▪ Migrate to wounds along fibrin strands in fibrin clot ▪ Just before new capillary buds as inflammatory phase subsides ▪Synthesize and deposit collagen, elastin, and proteoglycans ▪ Fibrous tissue** -after day 5 wound fibrin disappears due to (tension) and collagen is deposited

Answer 3

Wound tensile strength ▪Wound maturation ▪ Type I (mature) increases ▪ Type III (immature) decreases ▪Reaches maximum within 2-3 weeks post-injury ▪Increased collagen leads to decreased fibroblasts: End of repair stage

Answer 4

* Fibroblast migration and proliferation * Collagen production * Capillary ingrowth * Macrophages are important!!

Answer 5

Capillaries invade wounds behind migrating fibroblasts ▪Interaction of extracellular matrix with cytokines: -Migration of endothelial cells - Proliferation of endothelial cells ▪New capillaries, fibroblasts, fibrous tissue ▪ Bright red, fleshy granulation tissue ▪ 3-5 days after injury

Answer 6

▪Fills defects and protects wounds ▪Barrier for infection ▪Surface for epithelial migration Source of special fibroblasts called myofibroblasts** ▪ Wound contraction ▪ Actin and myosin ▪ Not found in normal tissue, incised and coapted wounds, or tissue surrounding contracting wounds ▪Formed at wound edge at a rate of ▪ 0.4 to 1 mm/day

Answer 7

Begins almost immediately (24-48 hours) in sutured wounds: Primary closure healing ▪Begins in open wounds when granulation bed has formed (4-5 days): Second intention healing -cant do over scabs so need moisture / collagenase will dissolve scabs -4-5 days after injury -along suture tracts -does not occur over non-viable tissue -Energy dependent and related to oxygen tension: Anoxia prevents epithelial migration and mitosis

Answer 8

▪Primary Closure ▪ Sutured Incision ▪ Tissue Apposition: No granulation bed

Answer 9

▪Open Wound Healing ▪ Granulation (bright red) ▪ Contraction ▪ Epithelialization** (pale pink tissue around edge of wound)

Answer 10

Reduces the size of wounds ▪ Subsequent to fibroblasts ▪ Reorganizing collagen in granulation tissue ▪ Myfibroblast contraction at wound edges ▪Occurs simultaneously with granulation and epithelialization ▪ Independent of epithelialization** Centripetal ▪ Full-thickness skin edges are pulled inward ▪ 0.6 to 0.8 mm/day ▪Stops when: ▪ Wound edges meet ▪ Tension is excessive ▪ Myofibroblasts are inadequate ▪Wounds may be noticeable smaller by 5 to 9 days

Answer 11

▪Collagen has been adequately deposited ▪ 17-20 days ▪ May continue for years ▪Functionally oriented fibers become thicker ▪Type III collagen decreases while type I collagen increases

Answer 12

▪Most rapid gain in wound strength ▪ 7 to 14 days after injury ▪ Collagen rapidly accumulates in wound ▪20% strength: First 3 weeks after injury ▪Slow increase in wound strength, but normal tissue strength will never be regained ▪ 80% of original strength may be regained

Answer 13

-Systemic Factors * Patient -Local Wound Factors * Surgeon * Wound Environment

Answer 14

▪Age: ▪ Older patients ▪Nutrition: ▪ Malnourished – low protein ▪ Obesity ▪Concurrent disease: ▪ Hyperadrenocorticism ▪ Diabetes mellitus ▪ Hepatic disease ▪ Uremia drugs: ▪Corticosteroids ▪NSAIDs ▪Immunosuppression

Answer 15

-Tissue Handling * Procedure Duration * Suture Material * Suture Tension * Hematoma * Seroma

Answer 16

▪Infection ▪Foreign Body ▪Microenvironment: ▪ Oxygen Tension ▪ Temperature ▪ pH ▪ Topical Medications

Answer 17

* Definition: Infection involving a surgical site within 30 days of surgery (1 year if implants are involved) * Superficial (skin, SQ) * Deep (fascia, muscle, body cavity)

Answer 18

Account for one third of infections acquired in hospitals. They are bad because they can cause... * Patient morbidity or mortality * Increased cost (for drugs, prolonged hospitalization, sometimes need for reoperation or wound care) * Angry clients with suspicions about the surgeons’ competence

Answer 19

-killing of microorganisms

Answer 20

-Avoiding introduction of microorganisms

Answer 21

-complete absence of all microorganisms

Answer 22

-all of the accessible microorganisms on a surface (like the surgical site) have been removed or killed

Answer 23

-the body part is entered using aseptic technique and has few microorganisms present

Answer 24

-microorganisms are present (≥ a million/square centimeter)

Answer 25

- microorganisms and other foreign materials are present

Answer 26

-microorganisms multiplying and generally producing a reaction in the patient

Answer 27

* Hospital design * Cleanliness * OR design and cleaning protocols * Traffic * Number of people in OR * * Talking..... * Use of antibiotics*

Answer 28

* Used for some equipment sensitive to heat * Can only be used on instruments that can can be submerged in water * Regular bacteria are killed within about 10 minutes, but it takes 10-12 hours to kill spores * Irritating -> MUST rinse well * Respiratory and dermal irritant

Answer 29

-Prophylactic antibiotics are used to prevent infection rather than to treat it, so rules of duration of treatment are different * Which operations are they appropriate for? * Those in which there is significant risk of infection (contaminated or dirty operations, for example) * Long surgeries (> 90 minutes) * When large implants are placed * When infection would be catastrophic

Answer 30

* Which antibiotics ? * Staphylococcus and Enterobacter are the most common bugs in dogs (although this varies with procedure). -Staphylococcus, Streptococcus, and E. coli are the most common bugs in horses, at least for colic surgery. * First generation cephalosporins very effective

Answer 31

* Antibiotics vs. aseptic technique * You want high tissue levels at the time the skin incision is made * IV route is best * Give 30-60 minutes before surgery begins * Repeat every 90 minutes -dont give more than 24 hours leads to resistance

Answer 32

* Chlorhexidine followed by alcohol is more effective than povidone iodine (Betadine) * Chlorhexidine binds to keratin – prolonged residual activity * But...approximately 20% flora still present in hair follicles * Contact time is important * Follow manufacturer’s recommendation * Minimum of 3 minutes contact time**

Answer 33

* Sterile prep – use sterile gloves * Use dominant hand to prep and other hand to pick up the gauze * Circular pattern – from incision site  periphery * Do not go back to incision site with the same sponge * Don’t scrub too hard (skin abrasions)

Answer 34

* Initial layer – use four quarter drapes around the prepped area * Fold the drape edge (makes 2 layers) for extra protection right around the wound...and to protect your fingers while placing it * Secure with towel clamps * DO NOT readjust the drapes once placed * DO NOT reuse the towel clamps once they’ve penetrated skin * Final drape – Single large drape (waterproof) to cover the entire patient and table * DO NOT use a penetrating towel clamp to secure the final drape * OK to use non-penetrating clamps but not to the patient

Answer 35

* Waterproof impermeable barrier * Cuffs are not impermeable – cover with gloves * Wet = contaminated: change gowns if wetness soaks through * Use new gown for each surgery * Paper vs. treated cloth * No difference in SSI as long as waterproof

Answer 36

* Attention to aseptic technique * Tissue trauma: Minimize by knowing anatomy and gentle technique * Amount of hemorrhage * Dead space * Surgical time: Infection rate doubles each hour of surgery!

Answer 37

-Surgery classification (overall infection rate 5.1%) * Clean (2.5 % infection rate) * Clean contaminated (4.5 % infection rate) * Contaminated (7.3 % infection rate) * Infected (18.1 % infection rate) ** GI and feet are more prone to infection*

Answer 38

* General health(ASA classification, obesity) * Distant infection (dogs with periodontitis are more likely to develop infection in their total hip replacements) * Duration of hospitalization * Increased risk of nosocomial infection with longer hospitalization * Total anesthesia time * Hypotension, hypothermia during surgery increase chances of infection

Answer 39

get Signalment and history: * Duration of Injury * Mechanism of Injury * Treatment -estimate blood loss -control hemorrhage -restrict movement -garden hose lavage -pressure bandage -apply appropriate support (reduce stress and trauma)

Answer 40

* Non-stick telfa with kling gauze * Rolled cotton, gamgee, quilt * Brown gauze or polo * Vet Wrap * Elastoplast

Answer 41

* Location of Wound * Extent of Injury * Age of Wound * Condition of Wound

Answer 42

* Sedate * Local Anesthesia * Sterile Lube in Wound * Clip and Prep * Explore Wound * Involved Structures * Wear gloves * Exam * Sterile -palpation, ROM, listen for crepitus with stethescope, further diagnostics

Answer 43

Intra-articular or intra-thecal antibiotics * Aminoglycoside: * Gentamicin * Amikacin

Answer 44

* Goals: * Remove Contamination * Remove Devitalized Tissue * Eliminate Infection

Answer 45

* Sharp * Autolytic * Bandage (mechanical) * Enzymatic * Biosurgical

Answer 46

* Goals: * Remove Debris * Reduce Bacterial Numbers * Mechanics of Lavage: * Ideal Pressure – 7 psi * Low Pressure Ineffective * Avoid High Pressure

Answer 47

* Garden Hose * 1L bag with 300 mmHg pressure cuff = 7-8 psi: **Best method * 35 cc with 19 g needle = 18 psi: Less than ideal * Pulsavac ideal lavage solutions are: nonirritating, bactericidal, cheap

Answer 48

* Prophylaxis: Before Contamination * Therapeutic for: * Cellulitis * Open Synovial Structures * Severe Muscle Injury