Coagulation (ATE2639L)

Question 1

Vasoconstriction

Answer 1

• First thing that occurs when an animal is cut
• Helps stop blood flow
• Allows platelet plug to form and for coagulation to occur

Question 2

Primary Hemostasis

Answer 2

Platelet or Vessel Problems
* thrombocytopenia
* poor platelet function
* vascular disorder (rarely)

Question 3

Secondary Hemostasis

Answer 3

Clotting Factor Problems
* intrinsic pathway
* extrinsic pathway
* common pathway

Question 4

Coagulation Cascade

Answer 4

Secondary hemostasis
* Coagulation normal within 5 minutes
* Factors occur like a domino affect (previous factor triggers the next one)
* Plasma factors formed in the liver
* 12 factors, all numbered
* End result is fibrin - supports platelet plug
* Required healthy liver, Vitamin K, and Calcium

Question 5

Platelet Estimate

Answer 5

• Normal = 8-12 platelets / OIF
• 1 platelet / OIF = 15-20,000 / mm3
• Fast and accurate

Question 6

Platelet Counts

Answer 6

• Dog: 200,000 - 500,000/mm3
• Cat: 300,000 - 800,000/mm3
• Bleeding starts <50,000/mm3

Question 7

BMBT

Answer 7

Detects Primary Hemostasis
* abnormal occurs with thrombocytopenia, thrombocytopathia, vonWillebrand dz, vascular disorders
* normal is <4 minutes

Question 8

Cuticle Bleeding Time

Answer 8

Detects overall hemostatic function
* does not differentiate betweem primary and secondary
* dog = <5 minutes
* cat = <3 minutes

Question 9

ACT Test

Answer 9

• Looks at Intrinsic and Common coagulation factors
• Helps diagnose specific clotting disorders
• Diagnose sub clinical coagulopathies prior to surgery
• Severe thrombocytopenia may slightly prolong time

Question 10

ACT Test
Set Up

Answer 10

• Tube with diatomaceous earth or kaolin
• Preheat tube to 37 C
• 2 mL of blood, midstream sample
• Timer starts when blood enters tube
• Mix and place back into 37 C
• Check after 30 seconds, then every 5 for clots

Question 11

ACT
Normals

Answer 11

• Dog: 90-120 seconds
• Cat: 60-75 seconds

Question 12

aPTT

Answer 12

Activated Partial Thromboplastin Time
* looks at intrinsic and common factors
* more sensitive than ACT
* good for hereditary and acquired bleeding disorders

Question 13

PT

Answer 13

Prothrombin Time
* looks at extrinsic and common factors
* best test for rodenticide poisonings and evaluation of treatment

Question 14

Collecting for Coagulation Testing

Answer 14

• All blood drawn at once
• Avoid multiple “sticks”
• Do not collect from catheter
• Use small needles and small veins

Question 15

FDP

Answer 15

Fibrin / Fibrinogen Degradation Products
* detects defect in fibrinolysis (clot breakdown)
* should not be in circulation - fragments interfere with coagulation
* positive indicates DIC