Book 1 Flashcards
And a little bit of book 2 (323 cards)
1
Q
What cells produced TNF alpha?
A
M1 macrophages
2
Q
Anti-TNF monoclonal antibodies and recumbent, soluble receptors help with what diseases in humans
A
Crohn’s disease and rheumatoid arthritis
3
Q
Where do white blood cells marginate?
A
Post capillary venules and pulmonary capillaries
4
Q
What pro inflammatory cytokines do M1 macrophages produce?
A
IL-1B, IL-6, TNF-a
5
Q
What are the neutrophil granules and what do they produce?
A
Primary/azurophils: myeloperoxidase, defensins, lysosome hydrolases, proteases
Secondary: MMPs
Tertiary/gelatinase: preformed receptors
IL-1a, IL-1b, IL-6, TNF-a
6
Q
What is the precursor prostaglandin?
A
PGH-2
7
Q
The intracellular fluid compartment is what fraction of total body water and what percent of weight?
A
2/3 total body water
40% of weight
8
Q
The extracellular fluid compartment is what fraction of total body water, and what percent of weight? What are the two sub compartments and their percentages?
A
ECF is 1/3 total body water, 20% body weight
Plasma/IVF: 25%
Interstitial fluid: 75%
9
Q
How long does it take for isotonic crystalloids to equilibrate, and how much is left in the intravascular space?
A
20-30 or 30-60 min
Only 25% remains in IV space
10
Q
What is two times maintenance for IVF?
A
4-8 mL/kg/hr
11
Q
What are side effects of hypertonic saline?
A
Phlebitis and hemolysis
12
Q
Hypertonic saline is useful for what conditions
A
Head trauma or cardiovascular shock in patients more than 30 kg that need a large amount of IV fluids, but don’t have much time
13
Q
How long does IV volume expansion last after hypertonic saline?
A
Less than 30 minutes
14
Q
What are side effects of synthetic colloids?
A
They decrease factor 8 and vWF, impair platelet function, and decrease stability of fibrin clots by increasing fibrinolysis
15
Q
What are risks of 25% human albumin?
A
Potentially fatal, acute or delayed hypersensitivity reactions, volume overload, coagulopathy
Patient will have an increase in IgG against human albumin, so no repeat dosing
16
Q
What is the rate of treatment of chronic hypernatremia?
A
</= 0.5 mEq/kg/hr
17
Q
What is the calculation for free water deficit?
A
0.6 x weight x ((Na patient / Na normal) -1)
18
Q
What does a negative base excess mean?
A
Non-respiratory acidosis
19
Q
What is the equation for anion gap?
A
(Na + K) - (Cl + HCO3)
20
Q
Most blood gas analyzers report a value for base excess that…
A
Can only be used to assess the metabolic component of acid/base disturbances and is the difference between normal buffer base and the patient buffer base
21
Q
How do you calculate the amount of bicarbonate needed?
A
0.3 x body weight x base deficit
22
Q
What are the four types of shock?
A
Hypovolemic, cardiogenic, distributive, hypoxic
23
Q
What is the equation for oxygen delivery?
A
DO2 = CO x CaO2
24
Q
What is the equation for arterial oxygen content (CaO2)?
A
CaO2 = (1.34 x Hgb x SaO2) + (0.003 x PaO2)
25
What is the equation for oxygen uptake? VO2
VO2 = CO x (CaO2 - CvO2)
26
What is the oxygen extraction ratio equation?
O2ER = (VO2 / DO2) x 100
27
How can lactate increase even with normal perfusion
Type B lactic acidosis: impaired mitochondrial function due to sepsis, diabetes, neoplasia, drug/toxins
Type A is due to inadequate DO2
28
What is CVP and what is it a surrogate for? What is normal?
CVP is hydrostatic pressure, but is a surrogate for preload
Normal is 0-5 cmH2O
29
What is the lifespan of a platelet?
6 to 8 days
30
What is the method of action of antithrombin
Binds and inactivates thrombin (f2) and f10a
Neutralizes Kalinin, f7, f9, f11, and f12
Rate of neutralization increases when antithrombin binds heparin
31
What is a normal BMBT and what does it test?
Dogs < 3 min, cats 34 - 105 sec
Primary hemostasis
32
How does a vitamin K deficiency impact PT and aPTT
Prolongs PT because of short half-life of f7 (4 to 6 hrs)
Prolongation does not occur until a factor is less than 25 to 30% of normal
33
What is the best test for detecting hypercoagulability?
Thromboelastography (TEG)
Anemia: hypercoagulable
Polycythemia: hypocoagulable
34
How does desmopressin (DDAVP) work?
Binds V2 receptors and induces release of subendothelial vWF stores
For type I vWD
Works in 30 min, lasts 4 hrs
35
M1 vs M2 macrophages: which is pro-inflammatory and what does it secrete?
M1 are pro-inflammatory, secrete IL-1B, IL-6, and TNF-a
36
What are the primary functions of TNF-a?
Initiates production of pro-inflammatory cytokines, ROS, and chemotaxins
Has anti-tumor activity
37
What are the pro-inflammatory cytokines?
TNF-a, IL-1B, IL-6, IL-8
(alpha-beta-68)
38
What are the anti-inflammatory cytokines
IL-10, IL-1ra
39
What is the parent prostaglandin?
PGH2
40
Which COX enzyme is constitutively expressed?
COX-1
41
What induces expression of COX-2?
trauma, growth factors, pro-inflammatory cytokines
42
What are the functions of TXA-2 and what cells secrete it?
vasoconstriction and platelet aggregation
secreted by platelets and macrophages
43
What is the action of nitric oxide (NO) and how does it exert this effect? Is it pro- or anti-inflammatory?
Vasodilation - has direct effect by diffusion into smooth muscle
BOTH pro and anti-inflammatory
44
Acute phase proteins change by what % during inflammation? What is the major negative APP?
change by 25%
ALBUMIN is the major NAPP
45
What are the deoxyribonucleotide pairs in DNA?
Purines to pyrimidines:
Adenine to thymine
Cytosine to guanine
46
What are exons and introns in DNA?
Exon = coding DNA
Intron = non-coding DNA
47
What are the 4 types of stem cells?
embryonic
adult
fetal/perinatal
induced-pluripotent
48
What are the 3 types of stem cell potentcy?
Totipotent: cells from all layers, including fetal membranes
Pluripotent: cells from 1+ germ layer but not fetal membranes
Multipotent: limited to germ layer they originated from (hematopoietic, mesenchymal, neural)
49
What anti-inflammatory agents are produced by MSCs?
TSG6, IL-1ra, PGE2
(Study guide also says TNF-a?)
50
What is PRP?
Plasma that has a platelet concentration 3-5x > peripheral blood
51
IRAP (conditioned autologous sera) has a high concentration of what cytokine?
IL-1ra --> competitively inhibits IL-1B
52
How do you calculate an IVF rate that includes correcting dehydration?
BW x % dehydration = deficit in LITERS
+ estimated ongoing losses (urine 1-2 mL/kg/hr; insensible losses 20 mL/kg/day)
+ maintenance rate (rec: 70x(BW^0.75))
53
LRS, P-Lyte, and Norm-R use which buffers?
LRS = lactate
P-Lyte and Norm-R = acetate and gluconate
54
What can happen if HTS is administered at >1 mL/kg/min?
Vagally mediated hypotension, bradycardia, bronchoconstriction
55
What is the blood volume of a dog? Cat?
Dog: 90 mL/kg
Cat: 50 mL/kg
56
What are the actions of PTH?
Increase Ca levels:
- Mobilizes Ca from bone
- Increases resorption of Ca in renal tubules
- Activates Vit D/calcitriol to increase GI absorption
57
What is the action of calcitonin
Antagonizes PTH by inhibiting Ca resorption/release from bone to decrease Ca levels in blood
58
Distributive shock is characterized by what single major systemic change? What is its effect on afterload?
Massive vasodilation
Decreases afterload
59
Equation for MAP
MAP = DAP + (SAP - DAP)/3
also
MAP = CO x SVR
60
O2 toxicity occurs at an FiO2 of __% for __ hrs
>60% for 24 hrs
61
What is the primary physiologic activator of the clotting cascade?
Tissue factor (f3)
62
What is the most important activator of platelets?
Thrombin (f2)
63
What are the 3 anticoagulant pathways?
1. Antithrombin: inactivates circulating coag proteins, activated by HMW heparin
2. Activated Protein C: created when thrombin binds thrombomodulin --> inactivates f5 and f8 --> enhances fibrinolysis
3. Tissue Factor Pathway Inhibitor: inactivates f10 and f7/TF complex, increased by heparin
64
PT tests which clotting pathways?
Extrinsic (TF/f7), common
65
aPTT tests which clotting pathways?
Intrinsic, common
66
ACT tests which clotting pathways?
extrinsic, intrinsic, common
Less sensitive than aPTT
67
D-dimers are sensitive indicators for what conditions?
Thrombotic conditions (DIC/TE)
68
What are the 3 types of vWD?
- Type 1 = presence of all multimers in REDUCED concentration (most common); If severe ( < 20% vWF) --> spontaneous bleeding
- Type 2 = disproportionate loss of HMW multimers
- Type 3 = almost complete absence < 1% vWF --> severe hemorrhage before 1yr
69
What is a positive ELISA result for vWD?
<50%
70
What is Virchow's triad?
endothelial injury + vascular stasis + hypercoagulability = thrombotic tendency
71
What is the target aPTT during unfractionated heparin therapy?
1.5-2.5x normal
72
How does heparin work?
Inactivates f2 (thrombin) and f10
73
What is the pathogenesis of DIC? What is the mortality rate in dogs and cats?
Systemic activation of coagulation --> microvascular thrombosis --> compromises organ perfusion --> organ failure
50-75% mortality in dogs (sepsis, malignancy); 93% in cats (neoplasia, pancreatitis, sepsis, infection)
74
RER formula
30(BW) + 70
or
70(BW^0.75)
75
What albumin level is associated with increased postoperative complications?
<2 g/dL
76
Neutrophil killing depends on a PO2 of
PO2 > 40 mmHg
77
Angiogenesis is stimulated by what?
Macrophages and platelets
FGF, PDGF, TGF-B, VEGF, adhesins
78
What cells secrete the most VEGF?
Keratinocytes
79
Fibroblasts become myofibroblasts via
TGF-B1
80
Unwounded dermis primarily has what collagens in what %? Healing wounds have primarily what type of collagen?
Normal dermis: 80% type I, 20% type III
Healing dermis: primarily type III
81
How strong is a final scar?
Only 70-80% of unwounded tissue strength
Only 10% type III collagen in final scar
82
Order the breaking strength of the following tissues from most to least:
Skin, stomach, colon, bladder
Bladder > stomach > colon > skin
83
The strength of a GI closure significantly decreases during the first ____ due to _______ activity
During the first 48 hrs due to COLLAGENASE activity
84
Bladder gains 100% strength in ____ days
21 days
85
What are the differences in healing between dogs and cats?
Breaking strength of cutaneous wounds at 7 days better in dogs than cats
Granulation tissue earlier and more in dogs than cats
Contraction/epithelialization faster in dogs than cats
86
What is the critical colonization level for bacteria in tissue to result in infection?
10^5 bacteria/g
87
What is the strength of skin at 10-14 days post wounding? At 3 weeks?
5-10% at 10-14 days
25% at 3-4 weeks
88
What are the 3 classifications of SSI?
Superficial - skin/SQ only
Deep - fascia/muscle
Organ/space - anything deeper
89
How does surgical time affect the risk of a SSI?
Risk of SSI doubles for each hour of surgery
90
What is the reported SSI rate for clean surgery?
2.5 - 4.8%
91
What is a nosocomial infection?
Infection that occurs 48 hrs after hospital admission
92
Expected bacteria and prophylactic abx for each surgery type:
- Skin/recon + elective ortho
- Head/neck
- Open Fx
- Upper GI
- Hepatobiliary
- Lower GI
- Urogenital
- Skin/recon + elective ortho: Staph = cefazolin
- Head/neck: Staph/Strep/anaerobes = clinda, cefaz
- Open Fx: Staph/Strep/anaerobes = clinda, cefaz +/- aminoglycosides/fluoroquinolones
- Upper GI: Gram + cocci, Gram - bacilli, anaerobes = cefoxitin
- Hepatobiliary: Clostridium, Gram - bacilli, anaerobes = cefoxitin
- Lower GI: Enterococcus, Gram - bacilli, anaerobes = cefoxitin
- Urogenital = Strep/Staph/E. coli/anaerobes = cefazolin, ampicillin
93
What are the classifications for surgical procedures in terms of contamination level?
Clean = non-traumatic, uninfected + no break in asepsis + no inflammation elective, primarily closed 2-5% infection rate
Clean-Contaminated = controlled entry to hollow viscus, minor break in asepsis
Contaminated = open/fresh wound, incision into site with nonpurulent inflammation, major break in asepsis
Dirty = pus encountered, perforation of viscus, traumatic wound with devitalized tissues
94
What are the challenges of treating abscesses with antibiotics?
Pus = acidic pH, hypertonic, protein binding of selected drugs (aminoglycosides will bind to sediment)
Not good for penicillins (inactivated at pH < 6), aminoglycosides, and enro (work better in alkaline environments)
95
How do bacteria evade B-lactam antibiotics?
Beta-lactamase production
loss/change in porins
96
In addition to perioperative abx, what other things (3) will decrease the risk of SSI in surgery?
Normothermia, euglycemia, oxygenation
97
What materials cannot be sterilized with H2O2 gas/plasma/vapor?
Linen and paper --> absorb the H2O2
98
What materials cannot be sterilized with EtO?
nylon, polyvinyl chloride, polyvinylidene chloride, or foil
99
How does steam sterilization work? How should bowls be positioned?
kills via coagulation/denaturation of proteins with moist heat (including spores)
Water is a catalyst and heat is transferred by condensation
Bowls should be placed UPSIDE DOWN to prevent air trapping
100
Guidelines for gravity-displacement steam sterilization
121C for 30 min + 15-30 min dry time
132C for 15 min + 15-30 min dry time
101
What materials is dry heat sterilization good for? What is the protocol?
Sharps, powders, glass
160C for 120 min
102
How does ethylene oxide (EtO) sterilization work? What materials is it good for? What materials should you be mindful of?
Alkylation of proteins/nucleic acids
Good for heat and water sensitive things
Glass RESISTS EtO and rubber/plastic ABSORBS (requires aeration step)
103
How does ozone sterilization work? What materials cannot be sterilized this way?
O3 molecule readily oxidizes other molecules to destroy microorganisms (30-35C for 4 hrs)
NOT for wood/paper
104
How does plasma sterilization work? What materials cannot be sterilized this way?
electromagnetic energy to create plasma from vapor of H2O2, O2, or peracetic acid/H2O2 mix --> free radicals deactivate cell processes
NOT for linens, liquids, wood
105
What are the broad classes of sterilization indicators?
Physical
Chemical
Biologic
106
What are the classes of chemical indicators?
Class 1 = sterilization tape --> pack processed but limited info on parameters met
Class 2 = test for air removal (Bowie-Dick)
Class 3 = react to specific indicator [temp or time]
Class 4 = react to > 1 parameter
Class 5 = react to all parameters
Class 6 = monitor more specific guidelines (parameter required to combat prion infection)
107
What bacteria are used for biologic indicators? What was the failure rate of chemical indicators caught by these?
STEAM + OZONE + PLASMA = Geobacillus stearothermophilus
EtO = Bacillus atrophaeus
12% failure rate detected on chemical indicators
108
What is the storage time for (sterilization and wrapping):
Double-wrapped autoclaved/steamed
EtO Cloth
EtO Paper
EtO Plastic/tape
EtO plastic/heat sealed
Double-wrapped autoclaved/steamed: 96 wks
EtO Cloth: 15-30 d
EtO Paper: 30-60 d
EtO Plastic/tape: 90-100 d
EtO plastic/heat sealed: 1 yr
109
What is the ideal tooth angle for a ratchet on an instrument?
39 deg angle (better than 45 deg) --> enhanced security/engagement of interlocking teeth
110
Different tenotomy scissors
Stevens - ring-handled
Wescott - spring-loaded
111
What is the difference between straight tipped and curved tipped scissors?
Straight = better mechanical advantage
Curved = greater versatility/visibility
112
What are the crushing and non-crushing tissue forceps?
CRUSHING [tissues intended for excision]: R angle (vessel isolation) + Babcock + Allis + Oshner-Kocher
NON-CRUSHING: Doyen (thin/bowed jaws, fine long grooves) + DeBakey (unique long ribs) + Satinsky (partial vessel occlusion]
113
What is the ventilation requirement for the OR?
Minimum 15 air exchanges per hour
30-60% humidity
temperature 20-30C (68-73F)
114
What are the 2 types of corrosion and what are they caused by?
PITTING [pinprick holes from Cl- – saline, blood, water]
FRETTING [discoloration on friction surface]
115
What combination of antiseptics for patient prep can have residual antimicrobial activity on the skin?
Chlorhexidine gluconate (4%) + isopropyl alcohol (70%)
116
Which hand is more likely to have glove perforations in surgery?
What were the perforation rates for single versus double gloves?
Non-dominant hand more likely to get a hole
Single glove perforation = 12-30%
Double glove perforation = 10-45% for outer; 4-13% for inner
117
What antiseptic agent kills MRSA?
Chlorhexidine
118
When should you clip patients?
Within 4 hrs of surgery to reduce incidence of SSI
119
Do you use cut or coag when combining monopolar electrosurgery with instruments?
Cut
120
What are the 3 tissue effects of COAG with monopolar electrosurgery?
1. Fulgaration = holding electrode away from tissue in coagulation mode --> random dispersion --> carbonization + superficial coagulum instead of vaporization
o Controls bleeding when no discrete bleeder >> smoke/char/necrosis
2. Desiccation = direct contact with tissue in coag mode --> dehydration + protein denaturation --> coagulum
o Eschar from overheating; more efficient heat than fulgaration = deeper thermal necrosis/spread
3. Coaptive = desiccation coagulation when lumen of vessel is occluded by metal instrument --> collagen weld
121
What vessel sizes can be sealed with:
Monopolar electrosurgery
Ultrasonic/Harmonic scalpel
Bipolar vessel sealing
And what is the thermal spread of each technique?
Monopolar electrosurgery: <2 mm
Ultrasonic/Harmonic scalpel: < 3 mm; thermal spread 0-1 mm
Bipolar vessel sealing: < 7 mm; thermal spread 1-3 mm (EnSeal <2 mm)
122
What does laser stand for?
Light Amplification by Stimulated Emission of Radiation
123
How does wavelength impact tissue penetration and which lasers are associated with which categories?
Longer wavelength = shallow tissue penetration/absorbed by H2O --> high surface temp + good cutting + min collateral (CO2, Ho:YAG)
Short wavelength = deeper tissue penetration/not absorbed by H2O --> coagulative necrosis at unpredictable zones (Nd:YAG, Diode)
Ultrashort wavelength = vascular tissue/absorbed by Hb (Argon)
124
Rank the following lasers in terms of depth of penetration (least to most): Nd:YAG, Argon, Diode, Excimer, CO2
Excimer < CO2 < Argon< Diode < Nd:YAG
[excited cats are doing nothing]
125
How does the Argon laser work and what is it typically used for?
Blue/green light absorbed by Hb
good for vascular lesions and endoscopy
126
Define:
knot pull out strength
Knot strength
Knot Pull Out Strength = load required to break suture deformed by knot
Knot Strength = force to cause knot to slip
127
How does pH affect glycolide and PDS/nylon suture degradation?
Glycolide degrades faster in ALKALINE pH
PDS/nylon degrade faster in ACIDIC pH
128
What is special about CHROMIC catgut suture
curing with chromium salts --> increased collagen cross-links --> decreased absorption and decreased inflammatory reaction
129
Vicryl: generic name, how long until 50% tensile strength, and time for absorption
Polyglactin 910
50% TS at 2-3 weeks
absorbed 56-70 days
130
Dexon: generic name, how long until 50% tensile strength, and time for absorption
Polyglycolic acid
50% TS at 2-3 weeks
absorbed 90 days
131
Caprosyn: generic name, how long until 50% tensile strength, and time for absorption
Polyglytone
0% TS at 2-3 weeks
absorbed 56 days
132
Monocryl: generic name, how long until 50% tensile strength, and time for absorption
Poliglecaprone 25
50% TS at 1-2 weeks
absorbed 120 d
133
Biosyn: generic name, how long until 50% tensile strength, and time for absorption
Glycomer 631
50% TS at 2-3 wks
absorbed 90-110 d
134
PDS II: generic name, how long until 50% tensile strength, and time for absorption
Polydioxanone
50% TS at 5-6 wks
absorbed 180 d
135
Maxon: generic name, how long until 50% tensile strength, and time for absorption
Polyglyconate
50% TS at 4-5 wks
absorbed 180 d
136
What is the rule for vessel diameter compared to LDS vascular clip size? How do LDS staplers work?
Vessel diameter should be <2/3 but >1/3 the length of the clip
2 staples, divides in between them
137
What are the open/closed staple heights for TA staplers?
White: 2.5 --> 1.0
Blue: 3.5 --> 1.5
Green: 4.8 --> 2.0
138
When should you not use a circular stapler?
If combined tissue thickness is < 1 mm or > 2.5 mm
139
What are the toxic byproducts of cyanoacrylate glue?
Cyanoacetate and formaldehyde
140
What are Halsted's Principles?
Gentle tissue handling
Meticulous hemostasis
Aseptic technique
Preservation of blood supply
Elimination of dead space
Accurate apposition of tissue planes
Minimize tension
141
T/F: Sawing with a scalpel blade is appropriate for transecting a pedicle but not for skin
True
142
What arteries can be permanently ligated? (4)
Both common carotids (NOT in cats)
Brachial A
Femoral A
External iliac A
143
What veins can be permanently ligated? (7)
Both jugular veins (NOT cats)
Brachiocephalic V
Hepatic V
Both common iliac Vs
Both femoral Vs
LEFT renal V (dogs)
Vena cava caudal to liver (if chronic compression or with R nephrectomy)
144
How long can the following vessels be temporarily ligated for?
Descending thoracic aorta
Portal triad
Hepatic A
Splenic a/v
Renal a/v
Abdominal aorta
Descending thoracic aorta: 5-10 min
Portal triad: 10-15 min
Hepatic A: 30 min
Splenic a/v: 15-20 min
Renal a/v: 30 min
Abdominal aorta: 30 min
145
What is an Esmarch tourniquet? How to you calculate tourniquet pressure? What is the maximum time a tourniquet should be left on?
Elastic wrap applied from distal to proximal to remove blood
Tourniquet P = bandage tension / (radius of curvature of limb x bandage width)
Max time = 1.5-2 hrs
146
How do mechanical hemostatics work?
Absorb blood to provide a mechanical barrier/tamponade, rely on normal hemostatic mechanisms, absorbable
147
What are 5 types of mechanical hemostatics, an important fun fact, and their resorption time
- Gelatin (Gelfoam) - swells in contact with blood, resorbed by granulomatous inflammation in 5 wks
- Cellulose (Surgicel) - bactericidal, acidic so can denature thrombin, resorbed in 2-6 wks
- Polysaccharide spheres - concentrate solid components of blood by dehydration, increase in volume 500%
- Bovine type II collagen - enhances platelet response, absorbed by fibroblast remodeling in 8-10 wks
- Bone wax/ostene - mechanical blocking of bone surface
148
What active hemostatic can be combined with gelatin (but NOT cellulose) to increase its efficacy?
Thrombin (f2)
149
What is the major disadvantage of hemostatic sealants? How quickly are they absorbed?
Swelling 400%, resorbed in 4-8 wks
150
Why do Greyhounds bleed?
Altered fibrinolysis. 1/3 will bleed within 3 days postop.
151
How does desmopressin function in relation to clotting?
Stimulates vWF and f8 release from endothelial cells in dogs with vWD
152
What is LaPlace's Law for bandage pressure?
Bandage P = NT/RW
153
How do alginates work for hemostasis?
Release of Ca promotes clotting cascade. NOT for intracavitary use
154
At what fluid production rate should a wound drain be removed?
<0.2 mL/kg/hr
155
What is Poiseuille's Law for drain flow and what effect will doubling the drain's diameter or halving its length have?
Laminar flow (F) = dP(pi)r^4 / 8nL
Doubling drain diameter increases flow by 16x
halving drain length increases flow by 2x
156
What are the two types of vaporizer output?
Variable bypass (most common) = 2 flows merge before exiting
Measured flow = gas and diluent flow set independently
157
What are the 3 vaporizer methods
Flow over (most common) = carrier as passes over inhalant reservoir
Bubble-through = carrier gas bubbled up through reservoir bottom
Direct injection (desflurane) = atomized inhalant into stream of carrier gas
158
What are the two types of vaporizer circuit systems?
Out of circuit (most common) = constant dose regardless of minute vol
In circuit = output depends on minute vol
159
What is the weight cut-off for rebreathing vs non-rebreathing systems?
Rebreathing for > 5 kg
Non-rebreathing for < 5 kg
160
What does the internal pressure regulator on the anesthesia machine reduce the tank pressure to?
45-50 psi
161
Pressure and volume of a full E/green O2 tank?
1900 psi
660 L
162
What is the ideal I:E ratio for PPV?
1:2
range 1:1 to 1:4
163
What is the starting PIP and tidal volume?
PIP 12 mmHg
Tidal vol 10-15 mL/kg
164
Describe the capnograph for
Hypoventilation
Rebreathing
Leak
Hyperventilation
Arrest/Disconnected
Hypoventilation = progressively taller peaks
Rebreathing = progressive elevation of the baseline
Leak = shark fin
Hyperventilation = progressively shorter peaks
Arrest/Disconnected = sudden decrease to flatline
165
What type of cycling is available for ventilators?
Time, volume, and pressure cycled
166
What gas flow is required to prevent rebreathing of CO2 in a non-rebreathing system?
200-500 mL/kg
167
What system should the O2 flush valve NOT be used with? What is the flow rate?
NOT for non-rebreathing systems - risk of barotrauma
30-50 L/min
168
What is the difference between ascending and descending bellows?
Ascending = descend during inspiration, leaks are more obvious
Descending = descend during expiration
169
How does a pressure-cycled ventilator work?
User sets the desired PIP and expiratory length in seconds
170
What is the minute ventilation calculation?
RR x TV
171
What is an animal's residual capacity volume?
45 mL/kg
172
What is normal CVP?
0-8 cmH2O, 0-5 mmHg
173
What changes will you see in CVP with a fluid challenge in a patient with
Hypovolemia
Hypervolemia
Hypovolemia - bolus may not change CVP
Hypervolemia - bolus will increase CVP by 3-4 and stay up or slowly come down
174
What are methods for measuring cardiac output? (4)
Aortic banding = gold standard
thermodilution
Lithium
NiCO
175
What strategies lead to increased intrapleural pressure over a respiratory cycle
Large tidal volume, increased PEEP, short expiratory times
176
What 3 receptors do opioids work on?
Mu = analgesia/side effects
Kappa = analgesia
Delta = regulates mu
177
Rank the potency of the following opioids from most to least: oxy/meperidine, methadone, fentanyl, hydromorphone, buprenorphine, morphine
Fentanyl (100x) > buprenorphine (40x) > oxy/meperidine (10x) > hydro (8x) > methadone (2x) > morphine (1x)
(Francine bought oranges Monday; Henry made macaroni)
178
How does tramadol provide analgesia?
serotonin/adrenergic receptors
Cats are able to make a large amount of the M1 metabolite, but dogs aren't
179
Which benzodiazepine is safest for animals with hepatic dysfunction?
Midazolam - water soluble
180
What is the alpha-2 selectivity of: xylazine, detomidine, romifidine, and medetomidine/dexmedetomidine
xylazine 160:1
detomidine 260:1
romifidine 340:1
med-/dexmedetomidine: 1600:1 (dexmed is 2x more potent than medetomidine)
181
What are the side effects of ketamine?
muscle rigidity, increased salivation, mild sympathomimetic (increased cardiac work), and **increased IOP/ICP**
Depends on renal excretion
182
What are the side effects of etomidate?
emesis, **adrenal suppression that can last for up to 6 hrs postop** so do not use in critically ill patients with Addison's
183
What is the MOA of alfaxalone and what are the main side effects?
Steroid GABA agonist
Decreases cardiac output and causes apnea (less commonly than propofol)
184
Rank the inhalant anesthetics in order of highest to lowest MAC (halogen, desflurane, nitrous, sevoflurane, isoflurane)
Nitrous (200%) > desflurane (7.2%) > sevo (2.1%) > iso (1.3%) > halo (1%)
Cat MACs are all slightly higher than the dog MACs
[No Dogs Swim In Heaven] or alternatively, [No Dan, Sexual Innuendos are Harrassment]
185
MAC can be reduced by... (3)
Other drugs, hypothermia (decrease 5% per 1 deg C), and decreased cardiac output
186
How does lipophilicity affect the actions of local anesthetics? What is the relationship between bupivacaine and lidocaine in terms of lipophilicity and potency?
More lipophilic = slower onset and longer duration
Bupivacaine is more lipophilic and 4x more potent than lidocaine
187
Are a or C fibers more susceptible to local blocks?
a fibers (periphery, myelinated)
188
What is the difference between depolarizing and non-depolarizing neuromuscular blockers? Which drugs are commonly used in each category?
Depolarizing = Succinylcholine --> triggers depolarization but doesn't allow repolarization, trigger for malignant hyperthermia
Non-Depolarizing = Atracurium/Vecuronium --> binds receptor but doesn't depolarize --> smoother onset, shorter duration , MUST use PPV
189
What are reversals for neuromuscular blockers, what is their MOA, and when do you administer them?
Neostigmine and edrophonium, anticholinesterases, administer after all train-of-4 twitches return
can give anticholinergic beforehand to prevent bradycardia, sinus arrest, bronchospasm, and salivation
190
What is the MOA of anticholinergics? What are the primary 2 drugs we use?
Parasympatholytics - decrease vagal tone by binding muscarinic receptors
Mimic the sympathetic nervous system
Atropine and glycopyrrolate
191
What are the differences between glycopyrrolate and atropine in terms of potency, onset/duration, and ability to cross the BBB?
Glyco has 4x potency
Atropine can cross the BBB and has faster onset/shorter duration
Glycopyrrolate takes several min for onset and lasts longer (1 hr)
192
What does the breaking strength of 2-0 barbed polypropylene suture correlate to in smooth suture?
3-0 smooth polypropylene
193
How is the EtCO2 value related to PaCO2?
EtCO2 is 2-6 mmHg less than PaCO2
194
What is the best opioid for epidurals?
Morphine --> has low lipophilicity and will provide analgesia for 12-24 hrs
195
What dose of atropine will increase the heart rate by 50% for 30 minutes?
0.04 mg/kg IV
196
T/F: Propofol has extrahepatic metabolism
True, good for patients with hepatic disease
197
How does etomidate work?
GABA agonist
Causes adrenal suppression
198
COX1:COX2 ratios of
Carprofen
Meloxicam
Mavacoxib
Firocoxib
Robenacoxib
Etodolac
Carprofen: 17
Meloxicam: 3
Mavacoxib: 21
Firocoxib: 300-400+
Robenacoxib: 150
Etodolac: 0.5
199
What is tepoxalin?
Non-selective COX/LOX inhibitor --> inhibits COX1/2, LOX5, and TXA2
LOX activity may reduce GI toxicities
200
Which 3 NSAIDs undergo enterohepatic circulation? Why is this significant?
Naproxen, carprofen, etodolac
Increased risk of GI upset
201
Low stroke vol from myocardial dysfunction should be addressed with a positive inotrope. Which two drugs are most commonly used and what is their MOA?
Dobutamine: B agonist
Dopamine: B agonist and alpha agonist
202
What two alpha-adrenergic vasopressors can be selected as a first line to reverse vasodilation?
Phenylephrine: a1/2 agonist
Dopamine: a1/2 agonist and B1/2 agonist
203
What are the differences in the effect of dopamine based on the dose?
Low dose: vasodilation from B2
Medium dose: increased heartrate from B1 effects
High dose: Vasoconstriction from A1 effects (10-20 mg/kg/min)
204
Clinically, norepinephrine lacks effects at which a/B receptor?
No clinical effects at the B2 receptor
205
What is the MOA of amantadine?
NMDA antagonist and dopamine agonist
206
Bioavailability of chondroitin sulfate?
5% bioavailability in dogs
Chondroitin sulfate is the most common glycosaminoglycan in the body
207
What percent of glucosamine is absorbed?
90%
208
What is the most effective anti-inflammatory fatty acid?
Eicosapentoic acid (EPA)
209
How does HCM affect cardiac function?
diastolic dysfunction and impaired ventricular filling --> decreased SV and CO
210
What anesthetic agents should be avoided in patients with cardiac disease?
Alpha2 agonists, ketamine (HCM), anticholinergics (increase HR and O2 demand), and lidocaine if in 3rd deg AV block
211
What two drugs should be avoided for patients with hyperthyroidism? For patients with Addison's?
Hyperthyroid: avoid ketamine (thyroid storm) and NSAIDs (occult renal insufficiency)
Addison's: avoid ketamine (increases sympathetic stimulation) and **etomidate**
212
What is the Branham reflex?
reflex decrease in HR after PDA ligation due to sudden increase in afterload
213
What is the classic sign of V/Q mismatch on a blood gas?
Hypoxemia WITHOUT hypercarbia
214
How does hypoalbuminemia affect many anesthesia meds?
Increases the amount of free circulating drug
215
What is the only drug that has been shown to negatively affect neonatal survival in dystocias?
Xylazine
XYLAZINE KILLS BABIES (and also dogs, don't give it to dogs)
216
What are the 5 dental blocks?
Maxillary
Infraorbital
Major palatine
Inferior alveolar
Middle mental
217
Describe the maxillary block
admin just caudal to last molar where maxillary n enters infraorbital canal thru maxillary foramen
218
Describe the infraorbital block and what it blocks
admin at infraorbital foramen or inside infraorbital canal; blocks incisive bone + maxilla + maxillary teeth/soft tissues
219
Describe the major palatine block and what it blocks
admin through thick palatal mucosa rostral to major palatine foramen (which is at level of upper PM4); blocks palatine shelf of maxilla
220
Describe the inferior alveolar block and what it blocks
admin intraorally thru alveolar mucosa at lingual surface of mandible (or extraorally thru skin at notch of ventrolingual surface of mandible); blocks mandibular body + all mandibular teeth/soft tissues
221
Describe the middle mental block and what it blocks
admin at middle mental foramen ventral to mesial root of PM2 (dog) or halfway b/w canine/PM3 (cat); blocks rostral mandibular body + teeth rostral to inj + soft tissues
222
What two anesthetic drugs increase intraocular pressure?
Ketamine and propofol
223
4 causes of hypothermia and what t% of heat loss they account for
Evaporation (minimal)
Conduction/cold surface (10%)
Convection/cold air (30%)
Radiation/body heat floating away (50%)
224
What are the 5 causes of hypoxemia
Hypoventilation
V/Q mismatch
Low FiO2
Right to left shunting
Diffusion barrier
225
What is malignant hyperthermia, what indicates that it is occurring in surgery, and how is it treated?
Inherited ryanodine receptor mutation
1st sign is abrupt increase in CO2, then increased temp/HR
Tx: dantrolene, aggressive cooling, remove trigger, O2
226
Why is the ECG not a reliable indicator of cardiopulmonary arrest?
Electromechanical dissociation AKA pulseless electrical activity
227
What is special about how introducer sheaths are measured? What size French is 1 mm?
Measured by INNER diameter
3 Fr = 1 mm
228
What dose of contrast is ideal for IR procedures?
< 3 mL/kg of Iohexol
229
What is the recommended light source for thoraco/laparoscopic procedures?
Xenon
230
Insufflation limits in the chest/abdomen?
<3 mmHg in chest, 8-10 mmHg in abdomen
231
What are the 3 routes of metastasis?
Hematogenous (sarcomas)
Lymphatic (carcinomas and round cell tumors)
Seeding
232
What is the process of metastasis?
Process: detachment --> migration in surrounding tissue --> intravasation [entry of tumor cells into vascular/lymphatic vessel] --> circulation --> attachment to distant endothelial cell --> extravasation --> angiogenesis --> proliferation
233
What size mets can be detected on TXR vs CT?
TXR >6 mm
CT 1 mm
234
What are the 3 categories of margins?
Marginal (just outside pseudocapsule)
Wide (2-3 cm and 1 fascial plane deep)
Radical (entire compartment)
235
What is considered a "close" margin?
< 3 mm normal tissue
236
What are commonly used IHC stains for tumors?
Cytokeratin = epithelial/carcinoma
Vimentin = mesenchymal/sarcoma
237
How much do tissue biopsies shrink by?
32%
238
What nerves/spinal segments are assessed with the patellar reflex and the withdrawal in the front/back legs?
Patellar = femoral n, L4-6
Withdrawal in hind = sciatic n, L6-S1
Withdrawal in forelimbs = dorsal thoracic, axillary, musculocutaneous, median, ulnar, radial n (C6-T2)
239
What nerve/spinal segments are involved in the cutaneous trunci reflex?
Lateral thoracic, C8-T1
240
What cranial nerves are tested by vision and PLR?
CN 2, 3, 7
241
What nerves contribute to the perineal reflex?
Cd rectal branch of pudendal n = voluntary motor to ext anal sphincter
Perineal branch of pudendal n = sensory
242
What contributes the majority of parasympathetic innervation in the body?
Vagus n. - contains 75% of your body's parasympathetic fibers
243
What is bright on T1 vs T2 images (very broad)
T1 = fat bright
T2 = fat and fluid bright, more sensitive to pathology
244
What separates the cerebral hemispheres? What separates the cerebellum from the rest of the brain?
Cerebral hemispheres separated by falx cerebri
cerebellum separated by tentorium cerebelli
245
How does PaCO2 affect CNS perfusion?
A 1 mmHg inc/dec results in a 5% inc/dec in perfusion pressure
246
How is cerebral perfusion pressure calculated?
CPP = MAP - ICP
247
How does the Cushing's reflex work?
Dec perfusion --> ischemia --> increased vasomotor tone --> incr MAP --> baroreceptor activation --> reflex bradycardia
248
What is a normal ICP range
8-15 mmHg
249
At what ICP do you get reduced cerebral perfusion?
ICP > 30 mmHg
250
What makes up the BBB?
Tight junctions between endothelial cells
Astrocyte foot processes
Pericytes
Basal lamina
perivascular microglia
251
What are the primary immune/phagocytic cells of the CNS?
Microglial cells
252
Which antibiotics have the best penetration of the BBB?
TMS, fluoroquinolones, metronidazole, chloramphenicol, 3rd gen cephalosporins
253
How does secondary injury occur after primary mechanical damage to the CNS?
Initiated by direct injury to neuronal/glial cell membranes
1. damaged membranes --> increased IC Ca/Cl/Na --> cell swelling AKA cytotoxic edema
2. Reduced uptake of K and glutamate by astrocytes --> increased glutamate --> + NMDA receptors --> further depolarizes cells (increased IC Ca and Na) --> + proteases and phospholipase A2 --> inflammation and apoptosis
3. Microglial cells release ROS and pro-inflammatory cytokines --> demyelination
254
What connects the cerebral hemispheres?
corpus callosum
255
What do the cerebellar peduncles connect
Inferior: spinal cord to medulla oblongata
Superior: cerebellum and midbrain/medulla oblongata
256
What ligament is seen on a cervical ventral slot?
Dorsal longitudinal ligament
257
What are the 3 effects of increased IC Ca in CNS cells?
1. Activates IC proteases --> apoptosis
2. Activates phospholipase A2 --> eicosanoid production and inflammation
3. Binds IC Phos --> further reduced energy stores
258
What are the 3 types of CNS edema and their causes
Vasogenic - increased vascular permeability due to inflammation
Cytotoxic - increased IC Na/Cl/Ca
Interstitial - increased intraventricular hydrostatic pressure from CSF
259
What cells maintain CNS homeostasis
Astrocytes
260
What is the primary collagen type in bone? Cartilage? Fibrocartilage? Tendons?
Bone = 90% type I collagen
Cartilage = 50% dry weight type 2 collagen
Fibrocartilage = type I collagen
Tendon = type I collagen
261
What are the zones of articular cartilage?
Zone 1 = superficial
Zone 2 = transitional
Zone 3 = radial (has increased proteoglycan and reduced collagen to resist compression)
TIDEMARK
Zone 4 = cement line, mature/calcified cartilage
262
What are the two types of entheses?
**Fibrous entheses = mm attach to diaphyseal bones --> dense collagen bands (Sharpey’s fibers) that merge w/ periosteal membrane
Fibrocartilaginous = no periosteum, zone of fibrocartilage at osteotendinous/ligamentous attachment --> forms transition between collagen fibers of tendon/lig and bone
263
How does an action potential cause muscle contraction on a cellular level?
Individual fibers innervated by terminal branch of motor axon --> action potential --> Ach binds to sarcolemma --> depolarization + Ca+ release from SR --> Ca+ binds troponin --> conformational change in tropomyosin --> exposure to myosin binding site on actin --> myosin engages actin + releases ATP --> sliding of actin/myosin to shorten sarcomere
264
What are the two muscle fiber types?
Type 1 = Slow twitch, have more mitochondria for sustained but weaker contraction, use oxidative metabolism
Type 2 = Fast twitch, have fewer mitochondria for fast, strong contraction, anaerobic metabolism
265
What is the difference between large and small diameter fibrils in tendons/ligaments?
Large diameter - more stiffness/strength
Small diameter - larger surface area so more viscoelastic properties, are found in higher concentrations within the scar of healed tendons
266
Where in bone are MSCs most commonly found?
cambrium layer of the periosteum
267
What are the zones of the growth plate?
Resting zone (only vascular zone)
Proliferative zone --> type II collagen
Hypertrophic zone --> type X collagen and little ECM, predisposed to SH Fx
Zone of mineralization
Zone of ossification
268
What is Young's modulus?
Stiffness. Slope of elastic portion of stress-strain curve
269
What are the two types of primary bone healing and their criteria?
Primary bone healing = intramembranous ossification
Contact healing = < 0.01 mm gap, <2% strain, bone deposited parallel to long axis of bone
Gap healing = < 1 mm gap, <2% strain, bone deposited parallel to FRACTURE
270
What is the most common cause of failure with elastic plate osteosynthesis?
Plate bending (plastic deformation)
271
T/F: Cutting cones cause bone resorption and reduce interfragmentary strain
False. They cause simultaneous resorption and formation of bone
(the statement in this question is referring to secondary bone healing, where the bone ends are resorbed and the callus is formed, both to reduce strain)
272
What are the 5 steps in secondary bone healing?
Inflammation/granulation tissue formation
Intramembranous ossification
Soft callus formation
Hard callus formation
Bone remodeling
273
What are the classifications for open fractures?
Type 1 = wound < 1 cm (inside-out)
Type 2 = wound > 1 cm (outside-in)
Type 3 = extensive ST damage (a = adequate ST; b = periosteal stripping/bone exposure; c = arterial injury)
274
How many twists are needed to maintain tension in a twist cerclage wire? For a single loop cerclage? What is the strongest cerclage knot?
1 twist for twist wire
1.5 twists (with the wire tightener) for single loop
Strongest is the double loop cerclage
275
What is AMI proportional to for a nail? For a plate?
Nail: r^4
Plate: thickness^3
276
What % of medullary canal diameter should your implant fill for:
IM pin "alone"
IM pin + plate
ILN
Threaded pins for ESF (bone diameter not canal)
IM pin "alone" = 70%
IM pin + plate = 35-40%
ILN = 80% (70-90% of isthmus)
ESF pins 20-30% bone diameter
277
Why do locking screws have a larger core diameter?
They have greater bending/shear at the bone-screw interface
278
What do the colors on the DCP drill guide represent? Where is the screw positioned relative to the center of the hole with each side of the guide?
Green = neutral/load, 0.1mm offset
Gold = compression, 1 mm offset
279
What degree of compression can be achieved with a single eccentric screw in a 3.5+ plate? In a 2.7 plate?
3.5 mm = 1 mm compression
2.7 mm = 0.8 mm compression
280
For each 10% increase in medullary canal fill with an IM pin, how much is plate strain decreased by?
20%
281
With an ESF, where should pins be placed in relation to the fracture ends, the joint space, and the physes (in young dogs)
1/2 bone diameter from fracture ends
3/4 bone diameter from the joint
1 cm or 3 pin diameters from the physis
282
What are the types of viable and non-viable nonunions?
VIABLE NONUNION
o Hypertrophic = excess callus, excessive motion/lack of adequate mechanical environ, exceeds tolerable strain of tissues (elephant foot)
o Oligotrophic = no evidence of callus (hard to differentiate from nonviable), due to lack of cell activity, loose implants may contribute
NONVIABLE NONUNION
osteosynthesis cannot occur even with adequate fixation
o Dystrophic = poorly vascularized intermediate frag with callus formation at one end but not other
o Necrotic = major frag of comminuted fx undergoes devascularization & necrosis (sequestrum)
o Defect = large bone defect (lost from trauma, sx, necrosis/resorption), gap at fx site too large
o Atrophic = most extreme; defect at fx with resorption of frag at both ends
283
How tight should the screw driver be twisted for 2.0, 2.7, and 3.5 screws?
2.0 = 2 fingers
2.7 = 3 fingers
3.5 = whole hand
284
What are the core diameters for the following cortical screws:
1.5
2.0
2.5
2.7
3.5
4.5
5.5
1.5 = 1.0
2.0 = 1.4
2.5 = 1.7
2.7 = 1.9
3.5 = 2.4
4.5 = 3.1
5.5 = 3.9
(+0.1 mm for cortical drill bit size)
285
What are the 3 components of a biofilm?
Offending microbe
Microbe-produced glycocalyx matrix
Host-produced conditioning layer
286
What are the 3 mechanisms that allow bacteria in biofilms to be more resistant to antimicrobial agents?
Biofilm acts as molecular filter – glycocalyx impedes perfusion of antimicrobials to cellular targets
Quiescent/dormant growth of biofilm microbes (abx that rely on bacterial growth don’t work)
Harsh microenvironment adversely affects antimicrobial agents (lower pH, increased pCO2, decreased PO2, hydration)
287
What are the 4 properties of autogenous cancellous bone grafts?
Osteogenesis = supplies bone forming cells
Osteoinduction = capacity to induce bone formation
Osteoconduction = scaffold for MSCs
Osteopromotion = enhances (does NOT induce) bone regeneration
288
What is the mechanism by which cortical allografts heal?
Creeping substitution --> slowly resorbed and substituted with host bone
289
When can you repeat an autograft harvest from the humerus? From the tibia?
8 wks for humerus
12 wks for tibia
290
What factors lead to the osteoinductive effect of demineralized bone matrix?
TGF-B, BMP2, BMP7
291
What inflammatory cytokines are most associated with ECM degradation in OA?
IL-1
IL-17
IL-18
TNF-A
PGE2
Also ROS, MMPs, aggrecanases
292
What are the 3 stages of OA?
(1) ECM degrades + aggrecan molecule shortening + H2O absorption ↑ + collagen damage --> ↓ stiffness of cartilage
(2) chondrocytes try to compensate with proliferation and ↑ metabolic activity
(3) chondrocytes cannot keep up --> cartilage loss/eburnation
293
Which is the inducible COX enzyme? What cytokines classically induce it?
COX2 = inducible
TNF-a, IL-1
294
What prostaglandins mediate the adverse effects of NSAIDs?
PGE2 = important for gastric mucosal health
PGE2 and PGI2 = important for maintaining renal blood flow
TXA2 = important for clotting
PGI2 = important for preventing thromboembolic disease
295
What is the ideal ratio of avocados : soybeans?
1:2
296
What are the cell counts (x10^9/L) and % MONONUCLEAR cells for synovial fluid:
Normal
OA
Rheumatoid A
Non-erosive IMPA
Septic A
Normal: <2 ; 94-100%
OA: 2-5 ; 88-100%
Rheumatoid A: 8-38 ; 20-80%
Non-erosive IMPA: 4-370 ; 5-85%
Septic A: 40-270 ; 1-10%
297
N6 vs N3 fatty acids: which are pro- and which are anti-inflammatory?
N6 = pro-inflammatory
N3 = anti-inflammatory (EPA is most effective)
298
What are the the 4 types of non-erosive IMPA? (not the subtypes of idiopathic)
Idiopathic (4 subtypes)
Drug-induced
SLE/SLE-related
Breed-associated (Shar Pei and Akita)
299
What are the 4 subtypes of idiopathic IMPA
Type I: Idiopathic (most common, 50%) --> prednisone cures 60%, 1/3 relapse, 1/3 need continuous Tx
Type II: Infectious/Inflammatory (25%)
Type III: GI (15%)
Type IV: Paraneoplastic (unFOURtunate because you have cancer)
300
What are the 3 types of erosive IMPA?
Rheumatoid
Greyhound polyarthritis
Feline chronic progressive
301
What are the most common bacteria implicated in septic arthritis for dogs and cats?
Dogs: Staph pseud, Staph aureus, B-hemolytic Strep
Cats: Pasteurella, Bacteroides
302
What is the benefit of starting antibiotics within the first 24 hrs of septic arthritis?
Decreased cartilage loss, however GAG will still be lost because they are degraded before collagen
303
What are the 3 stages of muscle injury?
Stage 1 = myositis/bruising
Stage 2 = tearing of fascia
Stage 3 = fiber disruption + hematoma
304
What are the two classes of tendons in relation to their vascularization? How does it impact their healing?
Paratenon = vascularized tendons, better chance for rapid healing (gastroc, triceps)
Sheathed tendons = avascular, healing depends on intrinsic blood supply
60% strength at 6 weeks, 80% at 1 year post injury
305
What size arthroscope would be appropriate for a 20 kg dog?
2.7 mm 30 deg scope
306
What size scope is appropriate for tarsal arthroscopy?
1.9 mm 30 deg scope
307
What collagen is primarily found in the joint capsule?
Type 1 collagen
308
What are the 3 forms of osteochondrosis?
OC latens - microscopic lesions
OC manifesta - radiographic and macroscopic lesions, subclinical
OC dissecans - attached or loose cartilage flap + clinical signs
309
Sites of OCD
Humeral head
Medial humeral condyle
Medial coronoid process of ulna
Both femoral condyles
Both trochlear ridges
310
What are the two types of OC?
Type 1 = in center of joint surface (humeral head, humeral condyle, femoral condyles)
Type 2 = at periphery, retains vascular attachments (MCP ulna, trochlear ridge)
311
When does the medial humeral condyle fuse to the lateral?
6 weeks
312
When does the femoral capital physis close?
7-11 mos
313
When does the distal ulna/radius physis close?
8-12 mos
314
When does the tibial tuberosity physis close?
6-8 mos
315
What are the plexuses that supply the skin?
SQ/subdermal plexus, cutaneous plexus, subpapillary plexus
316
How does cutaneous perfusion differ between dogs and cats?
Dogs have > density of collateral SQ vessels than cats [cats have smaller # + wider distribution of cutaneous perforating w/in trunk]
317
Define:
Primary closure/1st intention
Delayed primary closure
Secondary closure/3rd intention
2nd intention healing
PRIMARY/1ST INTENTION = sutured; clean or clean-contaminated wounds
DELAYED PRIMARY = closed 2-5 days after wound; mild contamination + minimal trauma; BEFORE granulation tissue
SECONDARY/3RD INTENTION = AFTER granulation tissue; severely contaminated/traumatized
2ND INTENTION = via contraction/epithelialization; lower limbs
318
How long does it take for necrosis to declare itself after a crushing injury of the skin?
3-7 days
319
Differences between cats and dogs in terms of wound healing?
- Cats have ↓ cutaneous perfusion for 1st wk after sx with more rapid gain in 2nd wk (not diff from dogs at 2 wk)
- Cats have ↓ wound breaking strength at 1 wk
- Cats heal more by contraction dogs heal more by central pull from fibroblasts [cats contract]
- Cats have less granulation tissue with more peripheral location of granulation
320
Honey is best for what phase of wound healing? In what ways does it exert its antimicrobial effects?
Inflammatory/early repair
- Hyperosmotic
- Produces H2O2 via glucose oxidase on glucose
- Phytochemicals + Low pH stimulate B/T-cell prolif
Also
Autolytic debridement and enhances granulation tissue formation
321
What is the Inhibin Number for medical grade honey?
Amount of dilution to which honey retains antimicrobial properties
322
What are the benefits of negative pressure wound therapy?
Improves wound perfusion
Decreases edema
Stabilizes granulation tissue formation
Reduces bacterial load
Removes exudate
Induces release of VEGF
323
What wound VAC pressures are used for:
Standard wounds
Skin grafts
Septic peritonitis
Over gauze
Standard wounds: -125 mmHg
Skin grafts: -65 to -75 mmHg
Septic peritonitis: -75 to -125 mmHg
Over gauze: -80 mmHg
