Approach to the bleeding patient Flashcards
(43 cards)
In ml/Kg what is the total blood volume of:
- dogs
- cats
80/90ml/Kg
60-70ml/Kg
When there is blood loss which 3 life threatening situations need to be considered?
- Hypovolaemic shock
- Severe anaemia
- Brain or pulmonary haemorrhage
In a patient, what samples would you want to collect?
- Blood smear
- Full blood count (EDTA)
- Coagulation profile (Citrate)
- Biochemistry (heparinised plasma)
What are the steps when approaching a bleeding pateint?
- Attempt to quantify blood loss
- Identify life threatening situations
- Establish venous access and take samples
- Control haemorrhage
- Fluid replacement
What fluids should be given if a patient is hypovolaemic?
Crystalloids
“Shock rates”: recommend a bolus of fluids of?
1/4 of the animals normal blood volume
What are the 5 stages of haemostasis?
- Vessel injury
- Vascular contraction
- Primary haemostasis
- Secondary haemostasis
- Tertiary haemostasis
Describe primary haemostasis
Formation of the primary plug:
- Von Willebrand factor attached to the walls of vessels interacts with platelets and allows them to bind to each other and the vessel wall
What does secondary haemostasis involve?
Coagulation cascade resulting in the generation of thrombin
Compare when primary vs primary and secondary haemostasis is needed
- Small defect: platelet only (primary haemostasis)
- Large defect: requires platelets and stabilisation of the clot by cross-linked fibrin (secondary haemostasis)
What does tertiary haemostasis involve?
Fibrinolysis - plasmin
What are the clinical signs of secondary haemostasis defects?
- Deficiency in clotting factors
- Present more acutely with life-threatening blood loss
- subcutaneous or cavity bleeding e.g. haemothorax
- haematoma formation
Which vessel must you not sample from if a bleeding disorder is suspected and why?
Jugular vein
- it will be very hard to stop the bleeding and a pressure bandage cant be used on the neck
Which in house labs tests are used to differentiate 1 vs 2 coagulopathy
Primary coagulopathy (test of platelet function or number)
- Manual platelet count
- Buccal Mucosal Bleeding Time
- Von Willebrand factor
Test of Coagulation
- Prothrombin Time (PT)
- Activated Partial Thromboplastin Time (APTT)
In which situation should you use a buccal mucosal bleeding time test?
Should only be performed in a situation of a normal platelet count & normal clotting (PT/APTT) times – assessing platelet function
Give examples of disorders of primary haemostasis
- Thrombocytopenia
- Inherited thrombocytopenia
- Immune mediated thrombocytopenia
- Platelet dysfunction
- Von Willebrand disease
What is thrombocytopenia?
a condition in which you have a low blood platelet count
What are the causes of a thrombocytopenia?
- Lack of platelet production
- Increased platelet consumption
- Increased platelet destruction
- Splenic torsion
What can cause a lack of production of platelets?
- Bone marrow disorder
- Drug toxicosis
What can cause an increase in platelet consumption?
- Disseminated Intravascular Coagulation
- Acute severe haemorrhage
What causes a primary immune mediated thrombocytopenia?
IgG binding to platelets, resulting in their destruction
What causes a secondary immune mediated thrombocytopenia?
Secondary to drugs, infectious disease or neoplasia
- 5-7d of exposure of drug required to produce sensitisation and onset of thrombocytopenia
How would you treat an Immune Mediated Thrombocytopaenia?
If 1° treat with glucocorticoids, eg Prednisolone or Dexamethasone.
If 2° treat underlying disease of discontinue drug
What is the name given to decreased platelet function?
Thrombocytopathia
