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Flashcards in 19 Deck (22):
1

vessels that can be permanently ligated

BOTH common carotid arteries (NOT IN CATS)BOTH jugular veins (NOT IN CATS)Brachiocephalic v.Brachial arteriesHepatic veinfemoral arteriesBoth external iliac arteriesBoth common iliac veinsabdominal vena cava caudal to liver

2

why can't both common carotid arteries and jugular veins be ligated in cats

less collateral circulation vs Circle of Willis and vertebral artery

3

three main principles that can be used to augment hemostasis

1. reduce blood flow to affected areas 2. topical hemostatic agents3. anti-fibrinolytics

4

list methods to reduce blood flow to affected areas

1. digital P/tamponade2. topical vasoconstrictors3. induce hypotension/hypothermia4. distant occlusion of blood flow

5

length of time it takes to form a platelet plug and cross link fibrin for clot

platelet plug 30 scross link fibrin for clot 2-3 minutes

6

types of topical vasoconstrictors

1. epinephrine2. ephedrine3. adrenaline

7

ways to control distal blood flow

1. vascular clamps (bull dogs, statinsky)2. tourniquets (rumel, esmarch-limbs)3. fingers

8

times in normothermic patients to temporary ligatehepatic arterypringle maneuverthoracic aortaabdominal aortarenal artery/vein

hepatic artery 30 minutespringle maneuver 10-15 minutesthoracic aorta 5-10 minutesabdominal aorta 30 minutesrenal artery/ vein 30 minutes

9

what pressure applied to distal limb tourniquet can be associated with neurogenic degeneration

1000 mm Hgdegeneration of myelin of compressed nerveddeficit ~ 6 months

10

pneumatic tourniquets

used in human surgerydeliver controlled pressure--100 mm Hg above patients systolic pressuremay reduce complicationsocclusion time is measured

11

equation used for tourniquet pressure

pressure = T (bandage tension)/R(radius)Width(bandage)P = T/RWPressure is inversely proportional to bandage width

12

most recommendations for length of duration of bandage tourniquets

MAX 1.5-2 hours (corresponds with muscle depletion of ATP stores)release for 10-15 minutes before reapplication

13

complications of hemostatic agents

volumetric swellingexothermic reactionsimmunogenic reactionsFB reactionsinhibition of normal healing

14

types of mechanical hemostatic agents

1. porcine gelatin (gelfoam)2. bovine collagen II (ultrafoam)3. cellulose (surgicel)4. wax (bone wax)

15

MOA of mechanical hemostatics

Absorb bloodprovide a mechanical barrier or tamponadecreate a matrix for clot formation/stabilization

16

difference in MOA of collagen vs gelatin

collagen promotes platelet aggregation

17

suspected MOA of silver hemostatic agent

Ionization of the product with direct activation of vessel contraction and the clotting cascade

18

types/categories of hemostatic agents

1. Mechanical hemostatic agent→gelatins (gelfoam), collagens (ultrafoam), Cellulose (surgical), Wax (bone wax) 2. Active hemostatic agent→Thrombin (II), alginates3. Hemostatic sealants→fibrin (Tisseel), synthetic (duraseal)

19

list two absolute contraindications for hemostatic agents

1. DO NOT GO INTRAVASCULAR2. AVOID WITH AUTOTRANFUSIONS

20

Regarding in vitro mechanical hemostatic agents, rank the following in order of best to least (collagen sponge, cellulose, microfibrillar collagen, cellulose)

Microfibrillar collagen>collagen sponge>gelatin sponge>cellulose

21

How can gelatin be distinguished from cancer or an abscess with advanced imaging modalities?

The foam should have pockets of air before complete absorption

22

types of antifibrinolytics

delay fibrinolysis1. serine protease inhibitors (aprotin)2. lysine analgoes (EACA, tranexamic acid)--more potent