Haematology1 Flashcards
What factors does APTT measure
ii, V,viii,Ix, X, XI, Xii
Normal APTT time
26-40
Common causes of delayed APTT
Heparin, liver disease, DIC, Factor deficiency of VIII, IX, XI, XII, lupus anticoagulant
What is the opposite of heparin?
Protein Sulphate
Normal PT time?
11-16 seconds
True or false prothrombin time measures the intrinsic pathway?
False
Causes of prolonged pt?
Oral anticoagulants (warfarin), liver disease, vitamin k deficiency, DIC
What factors does PT measure?
2,5,7,,10 and fibrinogen
What does thrombophlastin do?
It is a plasma protein that AIDS coagulation by catalysing the conversion of prothrombin to thrombin
What is INR
International normalised ratio- used to standardise oral anticoagulation therapy
How do u calculate INR
= [pt of patient / or of control ] isi
Isi = international sensitivity
How is fibrinogen tested
Clauss technique- time f fibrin clot formation
What is a normal range of fibrinogen
1.8-3.6 g/l
What is thrombin time?
Rate of conversion of fibrinogen to thrombin
What are fibrin degradation products called
D-dimers
What is lupus anticoagulant
Antibody that binds to phospholipids and protein
What does a USs doppler measure?
Ultrasound that measures blood flow through a blood vessel
Is haematocrit required to determine clotting range for a patient?
Yes
What 6 FBC parameters are directly measured?
Haemaglobin, red blood cell count, white blood cell count, platelets, red cell distribution width, mean cell volume
How is mean cell haemoglobin calculated
Hb/ rbc
How is mean cellular haemoglobin concentration calculated?
Mchc= hb/haematocrit (PCV) %
How is haematocrit calculated?
PCV=rbc x mcv
What does ESR measure?
Rate at which red cells stick together and sediment
Why do red cells stick together during poor health?
Red cells normally have electrostatic charge that separates them- gamma globulins and acute phase proteins neutralise electrostatic charge
