Haematology Flashcards
(115 cards)
What are the indications of blood transfusions
- active bleeding in trauma or surgery or anything else
- SCD or thalessemia
- leukaemia
Hb is less than 80 and the patient is symptomatic
What is FFP
Frozen plasma
Is done to replace coagulation factors
Can be given in TTP, or to reverse warfarin or severe chronic liver disease
When is platelet transfusion required
When platelets are below 50 + active bleeding
Shouldn’t be transfused in patients with TTP or drug induced thrombocytopenia (heparin)
Ocular and neurosurgery
What is cryoprecipitate
Used to replace VIII and fibrinogen. After a massive haemorrhage
Or can be congenital fibrinogen deficiency
Transfusion reaction presentations
Pruritus
Jaundice
Shock
Renal fialaure
Flank pain
Haemoglobiinuria
Fever
Tachypneoa
Tachycardia
Hypotension
Treatment for AHTR
Fluid resus ‘
Correct electrolytes
What is Febrile non haemolytic transfusion reaction
No haemolysis occurs and fever occurs due to endogenous release of pyrogens
Give anti-pyretics
Transfusion complications on lungs
TRALI - acute noncardiogenic pulmonary oedema within 6 hours of receiving blood products
Neutrophil activation which releases o2 species that damages pulmonary vasculature + extravastion of fluid
- diuretics not helpful in this as not heart related. Steroids helpful as this is immune mediated and ventilation
TACO - (within 12 hours) patient already has underlying heart failure in which transfusion rate is not adjusted leading to circulatory overload. The heart cannot tolerate this overload which will cause hypertension leading to pulmonary oedema. Raised JVP
Treatment - respiratory support and diuretics
Anaphylactic transfusion reaction
Symtoms occur within 4 hours of transfusion
Caused by release of histamine by mast cells
Managed with steroids and fluids?
Septic transfusion reactions
Within 4 hours symptoms of sepsis occur
Most common organisms are staph a. And gram negatives
Treat with vancomycin and aminoglycosides
What occurs in vessel injury
BV constriction
Platelet activation
Activation of coagulation cascade
Clotting is down regulated by fibrinolysis, Protein C and S, anti-thrombin III
How to differentiate between petechiae, purpura and ecchymosis
Petechaie - less than 2mm
Purpura - 2mm to 1cm
Ecchymosis >1cm
Bleeding into deep tissues, joints and muscles suggest what
Coagulation factor deficiencies
What drugs can cause thrombocytopenia
Amiodarone
Carbamazepine
NSAIDs
Tamoxifen
What is ITP: immune thrpmbocytopenic purpura
Autoimmune condition mainly affecting women in which immune system attacks platelets targeting the GP IIb/3a complex. Trapped within the spleen and removed by splenic macrophages
Mild - gums, nose and heavy periods (might cause anaemia)
- no organomegaly should occur or lymphadenopathy
20-40s age and presents suddenly
Steroids treatment of choice
What is TTP
Rare disorder : Pentad
Thrombocytopenia (as platelets are used in making micro-thrombi)
RBC fragmentation
Kidney failure
Neurological dysfunction
Fever
VW protein is released from endothelial cells when required for platelet aggregation. In this disease ADAMTS13 ( a protease which cleaves VW protein when not needed) is deficient meaning lots of VW protein can clump together leading to micro thrombi. Micro thrombi cause micro vascular injury affecting all the above systems within the body. Presence of microthrombi can damage RBC)
Petechaie
Fever
Confusion
Headaches
Coma
What is the normal PT time and what pathway does it measure
10 to 14 seconds
Extrinsic pathway
What is normal PTT time and which pathway does it meausre
Intrinsic
25-38
What causes prolonged PT time
Defieciency in factor 12
Factor 7
Vitamin k deficiency 10 9 7 2
Liver disease
Causes of prolonged PTT time
Low factor 8,9,10 + 11
Von willebrand disease
haemophilia A + B
Haemophilia A
Low factor 8
X-linked
Haemophilia B
- low factor 9
X-linked
What is haemophilia C
Low factor 11
Treated by FAP
Role of VW protein
Is a glycoprotein that acts to platelet adhesion and helps to carry factor 8
In disease:
Platelet levels are normal, PT normal
PTT is prolonged and VW low. Factor 8 will also be low