Approach to the bleeding patient

Question 1

What is the total blood volume of dog/cat?

Answer 1

Dog = 80-90ml/Kg
Cat = 60-70ml/Kg

Question 2

What are the life-threatening problems associated with bleeding?

Answer 2

*Hypovolaemic shock
*Severe Anaemia
*Brain / pulmonary haemorrhage

Question 3

How would you stabilise the patient with >/<25% blood loss?

Answer 3

control haemorrhage (pressure)
<25% blood loss = replace with crystalloids
>25%blood loss = blood transfusion

Question 4

What are the steps to haemostasis?

Answer 4

1.Vessel injury
2.Vessel contraction
3.1* haemostasis (endothelium, platelets + vWF)
4. 2* haemostasis (Coagulation Cascade)
5 3*haemostasis (Fibrinolysis)

Question 5

What are the clinical signs of primary haemostasis defects?

Answer 5

bleeding from small holes (lack of platelets)

Question 6

What are the signs of secondary haemostasis defects?

Answer 6

Bleeding from large holes - subcut/cavity bleeding = haemothorax, haematoma formation, pulmonary haemorrhage.
Requires cross linked fibrin.

Question 7

What are the disorders of primary haemostasis?

Answer 7

1.Thrombocytopenia
2. von Willebrand Disease
3.Thrombocytopathia
4. Vascular diseases

Question 8

What are the causes of thrombocytopenia?

Answer 8

-lack of production = bone marrow disorders, drug toxicosis
-increased consumption = DIC, acute severe haemorrhage
-Increased destruction = immune mediated
-Increased sequestration = splenic torsion

Question 9

What are the primary + secondary causes of immune mediated thrombocytopenia?

Answer 9

1* = IgG binding to platelets
2* = to drugs, infectious disease, neoplasia (anaplasma, Leptospira)

Question 10

How would you treat immune mediated thrombocytopenia?

Answer 10

1* = glucocorticoids
2* = treat underlying disease / discontinue drugs

Question 11

What is vWF important for?

Answer 11

Platelet adherence

Question 12

How would you treat von Willebrand disease?

Answer 12

Cryoprecipitate

Question 13

What are the disorders of secondary haemostasis?

Answer 13

1.Vitamin K deficiency
2.Liver disease
3.DIC
4.Haemophilia

Question 14

What causes Vit K deficiency and why is this a problem?

Answer 14

Vit K deficiency from consumption of rodenticides (vit K antagonist)
Vit K = activation of factors ii, vii, ix, x of coagulation cascade

Question 15

What are the clinical signs of Vit K deficiency?

Answer 15

2-5Days after = epistaxis, melaena, haematoma, ecchymoses

Question 16

How would you diagnose and treat Vit K deficiency?

Answer 16

Dx = history, signs + coagulation testing
Tx = Vitamin K therapy (NOT IV)

Question 17

What does disseminated intravascular coagulation cause?

Answer 17

1.activation of coagulation
2.Microthrombi in organs
3.Ischaemia + necrosis
4.Multi-organ failure

Question 18

What are the lab abnormalities with DIC?

Answer 18

Prolonged PT, PTT
increased D-dimers and Fibrin degradation products (FDP)