Midterm Flashcards
Name the stages of wound healing and the associated times
0-5 min Coagulation 0-24h min Inflammation 2-5 days Debridement 4-21 days Proliferation 21 days-2 years Maturation
What is the lag phase of wound healing
Debridement
What is the log phase of wound healing
Proliferation
In wound healing, what is the hallmark of coagulation
Platelet plug (by platelets and vWF)
What time frame indicates Class 1 wound
First 6 hours, golden period
What time frame indicates Class 2 wound
6h- 12 hours
What time frame indicates Class 3 wound
> 12 hours
Describe tissues with accelerated healing times, compare to skin
Urinary bladder 100% in 14 days
GI - 75% in 14 days
LI - 50% in 14 days
Skin- 20% in 20 days
Describe a clean surgical wound
No break in aseptic technique, no GI or respiratory involvement
Describe a clean-contaminated sx wound
Small break in asepsis or entry into GI/respiratory
Describe a contaminated sx wound
Major break in asepsis, inflammation without infection, GI gross contamination
Describe a dirty wound
Devitalized, necrotic, pus/infection, gross debris
What are the 6 perfusion parameters
MM, mentation, CRT, extremity temperature, pulse strength/deficit, BP
What suture should be used for body wall closures
40 kg - 1
Horse 3
(or 0-5, 5-25, >25)- 3-0, 2-0, 0
Describe primary closure
Immediate closure in less than 6 hours (golden period
Describe delayed primary closure
Closure between 6h and 2d, in debridement phase prior to granulation
Describe delayed secondary closure
Greater than 2 days, after appearance of granulation tissue
Describe second intention closure
Allowing wound to heal on its own, no sx
Describe “skin sutures”
Epidermis and dermis
Describe “subcutaneous” sutures
Subcutis only
Describe “subcuticular” sutures
Subcutis and small amount of dermis
Describe “intradermal” sutures
In dermis only
What is the most versatile forceps
Brown adson
What direction are serrations on halstead mosquito; What directions are serrations on Carmalt
Perpendicular to jaw; parallel to jaw
What grip is like palm but has third finger in ring
Thenar eminence
Longer needle holders give more ___, shorter needle holders give more _____
Power, precision
What retractors are best for abdomen
Balfour (think belly)
What retractors are best for thorax
Finochetto (think fino-chest-o)
Which retractors are best for orthopedics
Gelpi and hohmann
What should instruments be rinsed in
Distilled or tap water
When are eyed needles used
First stitch of extracapsular repair
What needle does Dujo recommend for subcuticular tissue and why
Reverse cutting (taperpoint can dull)
How do reverse cutting needles open the skin
Cut rather than dilate like taperpoint
What needle is used for eye surgery
Spatula point
What type of pattern is cruciate
appositional, low/mod tension relief
What type of pattern is horizontal mattress
everting, tension relieving
What kind of pattern is vertical mattress? Describe the pattern
Everting but not as much as horizontal, stronger tension relief than horizontal, far far near near
What pattern is used in intestinal surgery? Why?
Gambee - reduces mucosal eversion
What layers does gambee go through
Mucosa and muscularis
What is the holding layer of the intestines
Submucosa
What type of pattern is lembert? what is it used for
Inverting continuous, used in stomach, bladder mucosa
What kind of patterns are Connell and Cushing, what is the difference between them
Inverting continuous; Connell enters lumen and Cushing does not- only goes to submucosal
What knot is used in extracapsular repair
Half hitch
What makes up the epidermis
Cuboidal and stratified epithelium
What makes up the dermis
Mostly collagen
What makes up the hypodermis
Fat and connective tissue
Where is the direct cutaneous artery and vein
Hypodermis
What are the clotting factors of the intrinsic pathway
12, 11, 9, 8
What are the clotting factors of the extrinsic pathway
3, 7
What are the clotting factors of the common pathway
10, 5, 2, 1
What is primary coagulation
Platelet plug
What is secondary coagulation
Fibrin plug from clotting cascade cleaving fibrinogen to fibrin
How long does the inflammation phase of wound healing last
0-24 hours
Describe the inflammation phase of wound healing
Platelets release cytokines (TGF, TNF, PDGF) to recruit neutrophils
When do macrophages enter the wound?
At max 36 hours, during inflammatory phase, after neutrophils are ramping down
What marks the beginning of the debridement phase
Macrophages
How do bacteria prolong debridement
Metalloproteinase and collagenase, change in pH
How long is the proliferation phase
4-21 days
What marks the start of proliferation phase
Influx of fibroblasts from cytokine release by macrophages (FGF, TGF, PDGF)
What material provides wound strength in proliferation phase
Type 1 collagen
When does contact inhibition occur
At end of epithelialization phase within proliferation phase when epithelial cells cross basement membrane and touch
What is contraction
Second intention healing at about 1 week, myofibroblasts produce actin and myosin to contract the wound by pulling ECM at 1mm/day
When is the second lag phase
21d-2y - Maturation phase
What happens in the maturation phase
reorganization of fibers, cross linking, linearization
T/F tensile strength is increased in Maturation phase
False- minimal at best
Name intrinsic wound healing factors
Hypoproteinemia, DM, malnutrition, anemia, cushings, infection, uremia
How does uremia affect wound healing
Down-regulates epithelialization and decreases collagen deposition
How does hypoproteinemia affect wound healing
Less protein for factors, less fibrous tissue deposition
How does DM affect wound healing
peripheral ischemia
What are the extrinsic factors of wound healing
Mechanism of injury (crush, shear, laceration), foreign materia, irradiation, antiseptics
When in wound healing should abx be used; which kind?
Class 2/3, clean-contaminated/dirty; broad penicillins, cephalosporins
What should lavage be performed with and at
Physiologic 0.9% saline at 6/7-8 psi via pressure cuff at 300mmHg
Layers of wet to dry
4x4 soaked in physio or hypertonic saline, dry lap sponges, vet wrap
When shouldnt wet to dry be used
After debridement
When are drains indicated
Dead space, pocketing, abscess
What is the preferred drain type, describe
Active (vs passive) - creates vacuum to remove fluid/dead space (butterfly and red top tube)
Describe passive drain
Penrose tubing using gravity
How long should drains be left in
3-5 days
What is the gold standard dx for septic peritonitis
Cytology (BG more than 20 difference, lactate
Name the causes of perforation
Foreign body, intuss, volvulus, abscess, granuloma, trauma, tumor
How does perforation affect wound healing
Decreased collagen synthesis (elevation in TNFa), collagen destruction by collagenases from bacteria
How can obstruction be diagnosed
US > rads - SI > 2 times L5 vertebral body
Diagnose peritonitis via abdominocentesis cytology
> 13000 nucleated cells, intracellular bacteria
Describe bilroth I sx
Pylorectomy with gastroduodenostomy
Describe bilroth II sx
Pylorectomy with gastrojejunostomy
Complication of bilroth I sx
Removal of common bile duct
What three things can cause surgical failure
Pre-existing peritonitis, foreign body in intestine, albumin less than 2.5 g/dL
Compare open vs closed drainage for peritonitis sx
Open many bandage changes, needs second sx, but can continually eval; closed less hospitalization, less infection, higher survival, no second surgery
What type of drainage does UF prefer
Closed
When should OVH/E be done to avoid mammary neoplasia
before 1st or 2nd heat in dogs, before 6 months in cats
What causes pyometra
Luteal phase progesterone
Vascular pedicle knots
Strangle or Miller’s
Preferred terminal knot- repro
Aberdeen bc smaller, les trauma, less infection
Closed vs open castration
Open enters vaginal tunic
1 complication- castration
Hemorrhage (hematoma, hemoabdomen, urerteral or urethral ligation)
1 complication- OVE
Hemorrhage, ureteral ligation, ORS
What is ORS
Ovarian remnant syndrome - worse on R side
Preferred peritoneal access in laproscopy
Modified Hasson (vs veress)
Light source- laproscopy
Xenon 100-300 watts
Telescope size- laproscopy
5mm (sometimes 10mm) bigger= wider field of view
Ligasure stats
vessels up to 7mm, withstand 3x systolic pressure (300mmHg)
Sterilize tools- laproscopy
Ethylene oxide or gas plasma
Cold sterilization of scopes- laproscopy
2% glutaraldehyde
Contraindications- laproscopy
Advanced or exploratory (adrenalectomy, choecystectomy, splenectomy)
Physio effects- laproscopy
Respiratory pressure, vena cava collapse at 20mmHg
Target pressures- laproscopy
Dogs-
Pain sources- laproscopy
Incision, peritoneal CO2 acidosis/irritation, neuropraxia of nerves from pressure)
Preferred technique- OVH, OVE laproscopy
OVH: 3 ports, on midline (pitcher- scope, instruments at 1st and 3rd);
OVE 2 ports- 1cm caudal to umbilicus (camera), 2-4 cm cranial to umbilicus
Closure of ports- laproscopy
5mm- Subcutaneous and skin; 10mm- linea, subcutaneous, skin
Common complication- gastropexy via scope
Seroma, splenic laceration, serosal tearing
Body wall closure- holding layers
Linea alba and external rectus abdominus sheath/fascia
Body wall closure- linea bites
Cranial- full thickness through linea; caudal 1/3 wide, partial thickness of ext. rectus fascia
Suture peritoneum?
No! Increases adhesion risks, mesothelial cells close on own in three days
Body wall closure- pattern
Continuous, 5 throws at start, 7 throws at end
Body wall closure- suture SA
PDS (or maxon polyglyconate) ( monofil absorbable
Body wall closure- suture LA
Vicryl #3 horses
Body wall closure- bite sizes/position
0.5-1cm from incision, apart
Suture material- most tensile strength
PDS, maxon (aka polydioxanone, polyglyconate)
How should you incise the skin
Parallel to Langers lines of tension
What is undermining
Removing subcu from skin
Skin closure- typical closure combination
Subcutaneous (or intradermal to avoid licking complications) and skin with continuous pattern (5-10mm between bites)
Subcutaneous skin closure- material, size, pattern
Non-reactive monofil absorbable PDS, vicryl, Maxon, monocryl; interrupted or continuous; 1-2 sizes smaller than linea (0- 4-0)
T/F subcutaneous is a holding layer
FALSE, need additional layer above
Cutaneous- material, pattern
(skin suture) Nylon mono NO BRAIDED, abs or non, Cruciate or simple interrupted
Intradermal- material, pattern
Absorb monofilament (vicryl, PDS, monocryl), 3-0 to 4-0; Deep-sup- sup-deep; 4 throws in knots
Brand name polydioxanone
PDS
Brand name polyglyconate
Maxon
Brand name polyglactin 910
Vicryl #3
Brand name polyglecaprone
Monocryl
Intradermal cons and pros
Difficult, slow, no dead space elimination, low tension only- cosmetic, no suture removal
Laparotomy (GI explore) advantages
Full biopsy, excision, address hemorrhage, intervention
Indications for laparotomy- diagnostic
PLE, hepatopathy (MVD, copper storage), neoplasia
Indications for laparotomy- therapeutic
Rads (free gas, dilated SI, foreign, herniation, GDV); abdominocentesis (high PCV, clots=acute hemorrhage, urine (creat/K >in fluid than serum), cylotoly( neutrophils, intracell bacteria), bile pigment
What is the holding layer for abdominal wall
External rectus fascia
Peri-op Abx
Cefazolin
Laparotomy prep- scrub skin
Clorhex gluconate 10 min, then 5 min in OR
Visualization in abdomen, L and R side help
L- mesocolon; R mesoduodenum
Where is the portal vein
Epiploic foramen under duodenum and ventral
Peritoneal lavage amount in contamination
50mL/kg
LA- most common sx complications- anesthesia
myopathy, neuropathy
LA- most common sx complications- sx
hemorrhage, airway obstruction
LA- most common sx complications- post op
Infection, dehiscence, colic, laminitis
Reduce anesthesia complications
MAP >60mmHg, pCO2 45-65, pO2 >60
pO2 saturation at 90%
Dog- 57/58mmHg; Horse 54mmHg
PCV/TP min- LA sx
20%, 3.5g/dL
How much blood in a 500kg horse
40L (8% body) (25L plasma)
Acute blood loss max horse
20-25% shock, 50% death - transfuse >10L lost
Safe amount blood from donor
20% blood total (1.6% BW kg)
Transfusion formula
(PCVdesired-PCVactual)/PCVdonated x patient blood volume (8% BW)
