With respect to thromboelastography and haemostasis:
With reference to the parameters labelled in Figure 1:
- CT (or R) (CLT in this figure)
- CFT (or K)
- Alpha angle
- MCF (or MA)
- LI30 (or LY30 or CL) (A30 in this figure)
- a) Explain what each parameter represents and what it measures. (60% marks)
Review the following thromboelastograms labelled A – E.
Diagram A represents a normal coagulation profile
- b) Describe the coagulation status indicated by diagrams B – E. (40% marks)
Answer and interpretation
a) Explain what each parameter represents and what it measures. (60% marks)
R (reaction time or clotting time) is the time elapsed until first measurable clot forms (amplitude of 2mm) and indicates the initiation of haemostasis and is dependent on presence of clotting factors.
K (kinetics or clot formation time) is the time taken to achieve a certain level of clot firmness (amplitude of 20mm) and indicates amplification of the clotting process. Dependent on fibrinogen.
Alpha angle reflects the speed of fibrin accumulation. Dependent on fibrinogen.
MA/MCF is the maximum amplitude or maximum clot firmness and is the highest vertical amplitude of the TEG tracing. Dependent on platelets and fibrin.
LY30 /CL (clot lysis) is the percentage of amplitude reduction 30 min after maximum amplitude and is a measure of fibrinolysis.
b) Describe the coagulation status indicated by diagrams B – E. (40% marks)
B – Anticoagulant therapy or factor deficiency
C – Platelet dysfunction or thrombocytopaenia or fibrinogen deficiency
D – Fibrinolysis e.g. use of t-PA
E – Hypercoagulable state
- Pass rate: 69%
- Highest mark: 9.3