Haematology Flashcards
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:
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
Causes of prolonged PTT time
Low factor 8,9,10 + 11
Von willebrand disease
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
What is VW disease treated with
Tranexamic acid?
What is the definition of haematocrit
Of the centrifuged sample what proportion of the blood is made up of red blood cells
What are the causes of microcytic anaemia
Iron deficiency anaemia
Thalessemia
Congenital sideroblastic anaemia
Anaemia of chronic disease
Lead poisoning
What can cause iron deficiency anaemia
Menorrhagia
Pregnancy
GIT malignancies
Oesophagitis
GORD
Coeliac disease
Hookworm - and schistosomiasis
Low iron diet - vegans
What is transferrin
A protein which is responsible for the transport of iron through out the body
What is ferritin
A protein which stores iron
What would the FBC picture look like in microcytic anaemia
Microcytic and hypochromic cells
Decreased MCV
Decreased MCH
Decreased ferritin
Decreased iron
Increased transferrin and TIBC
Blood film - anisocytosis (RBC are different sizes) + poikilocytosis (RBC are different shapes).
Causes of normocytic anaemia
CKD
Haemolytic anemia
Aplastic anaemia
Anaemia of chronic disease
Acute blood loss
Pregnancy
Hypothyroid
What can cause haemolytic anaemia
Glucose 6 phosphate deficiency (enzyme that protects the RBC from oxidative stress and destruction)
Hereditary spherocytosis - Rbc are sphere shaped and more fragile + prone to haemolysis
Haemolytic disease of the newborn
Sickle cell disease
Warm antibody autoimmune haemolytic anaemia - at higher temperatures plasma cells attack RBC causing their destruction - mainly IgG
Cold antibody autoimmune haemolytic anaemia - IgM at lower temperatures attach to RBC causing them to agglutinate and undergo destruction
What are Heinz bodies
Most commonly seen in G6P deficiency - when the body detects damaged Hb it tries to remove it from the cell leaving behind a small round blue black body known as a Heinz body
WAIHA is usually associated with what condition
CLL
CAIHA is usually associated with which conditions
Lymphoma
Mycoplasma
EBV injections
Which groups of women are at higher risk of having a baby with a NTD
BMI over 30
Previous child with NTD
FHX
Taking anti-epileptics
Diabetes
Coeliacs
Thalessemia
What does FBC look like in normocytic anaemia
Decreased hb
Normal MCV
Normal or increased ferritin
Increased bilirubin
Check reticulocyte count
What can cause G6P deficiency
X linked condition - thus affects males more
Anti- malarials
Sulfa drugs ( sulfonamides, sulphasalazine and sulfonylureas)
Causes of macrocytic anaemia
Megaloblastic - b12 defieicny, folate defeciency and secondary to methotrexate + pernicious anaemia
Non-megaloblastic - alcohol, liver disease, hypothyroid, pregnancy, reticulocytosis, myelodysplasia and cytotoxic drugs
What does the FBC picture look like for macrocytic anaemia
Decreased HB
Increased MCV
Decreased B12 and folate
On blood film hypersegmented neutrophils
What happens to TIBC in anaemia of chronic disease
It is Low. In comparison to in iron deficiency anaemia TIBC is high
Causes of hypo proliferative (reticulocyte count) normocytic anaemia
Leukaemia
Aplastic anaemia
Pure red cell aplasia
Other BM failure syndromes
What kind of investigations would you carry out to find the causes of microcytic anemia
Faecal occult blood test
Endoscopy
Colonoscopy
TTG-IgA test
Flow cytometry - diagnostic for paroxysmal nocturnal haemoglobinuria
Transvaginal ultrasound - may reveal cause of menorrhagia
What is thalessemia
Autosomal recessive condition which leads to insufficient haemoglobin production. Affects production of alpha or beta chains .
Most common in Mediterranean, Middle Eastern and Southeast Asians.
Electrophoresis is diagnostic test
Alpha chains coded for via gene on chromosome 16
Beta chains coded for by gene on chromosome 11
What is an important thing to consider in normocytic anaemia
Whether reticulocyte count is hypo or hyperproliferative