Haematology Flashcards
What are the three sizes of RBC in anaemia
Microcytic
Normocytic
Macrocytic
What are the two colours of RBC
Hypochromic - pale
Normochromic
What are reticulocytes
Immature RBC
What does low reticulocytes mean
Low - lack of production
High - hemolysis/ blood loss
What are most Microchromic anaemias
Hypochromic
What are examples of Hypochromic Microcytic Anaemia
- Iron Deficiency Anaemia
- Thalassaemia
- Chronic Inflammatory disease - usually normocytic but can be microcytic
- Sideroblastic Anaemia
What are example of Normocytic Anaemia
Chronic Inflammatory Disease - IBD, Infection Bone Marrow Failure/Malignancy Prematurity Recent Blood Loss Pregnancy Chronic Renal Disease HIV
What are examples of Macrocytic Anaemia
Vitamin B12 deficiency Folate Deficiency Hypothyroidism Alcohol Access Chronic Liver disease
What are the two types of Anaemia
Underproduction:
- Microcytic
- Normocytic
- Macrocytic
Normal Production:
- Haemolysis
What are causes of severe anaemia at birth
Haemolytic disease of the newborn
Bleeding: umbilical cord, internal haemorrhage
What is severe anaemia in the newborn called due to rhesus haemolytic disease
Erythroblastosis Fetalis
How does erythroblastosis fetalis occur
- Rh negative mothers previously sensitised to Rh+ve blood from previous pregnancy
- Production of Rhesus Antibodies
- These Antibodies cross the placenta
- These cause haemolysis of fetal RBC
What are the signs and symptoms of erythroblastosis fetalis
Hepatospelomegaly
Severe Anaemia
Jaundice
Oedmatous Fetus
What is the Rx of erythroblastosis fetalis
Prevention of sensitisation with Rh immune globulin during and following pregnancy in Rh-ve mothers
Intra-uterine Blood Transfusion
What are causes of Physcological anaemia in the newborn
Fall in haemaglobin from birth to 2 months
- Decreased RBC production
- Plasma dilution from increasing blood volume
- Shorter lifespans on neonatal RBC
- More fragile RBC
- Switch from HbF to HbA
Why does anaemia occur in prematurity
Low birth weight infants - poor erythropotein response (Low EPO) (promotes formation of RBC by bone marrow)
Breast milk erythopotein may not be sufficient for haematopoiesis
What is the role of breast milk for RBC
Erythopotein in Breast milk can help stimulate hematopoiesis
What are the signs and symptoms of anaemia and prematurity and how do you manage it
Poor weight gain
Pallor
Decreased activity
Tachycardia
Blood Transfusions
What are the main causes of iron deficiency anaemia in new borns
Poor Intake Blood Loss e.g GI bleeding Malabsorption e.g Coeliac Disease Trophics e.g Hookworm Increased Requirement e.g Infection, Breast feeding
How does iron deficiency anaemia present
Pallor Irritability Anorexia Tachycardia Cardiac Dilation Murmur
What is the treatment for iron deficient anaemia
Oral Iron (Ferritin) Therapy Common cause of failure non-compliance
What is Haemolysis
Increased RBC turnover/ destruction
shortened RBC lifespan e.g fragile abnormal ones
What are intra corpuscular causes of increased RBC destruction
- Haemoglobin
- Enzyme
- Membrane
What are extra corpuscular causes of increased RBC destruction
Autoimmune
Spleen hypertrophy/ Spleenomegaly
Plasma Factors
Fragmentation
What is a complication of long term haemolysis and/or transfusions
Iron Overload - affects all organs e.g Liver faliure, Heart Failure
How do you manage iron overload
Ferritin monitoring + imaging
Iron Chelation
What are two examples of haemoglobinopathies
Sickle cell disease
Thalassaemia
How are haemoglobinopathies diagnosed
- HPLC - High Performance Liquid Chromatography
- Hb Electrophoresis
What is Sickle Cell Disease
AR disorder - causing production of abnormal beta globulin chains - HbS rather than HbA
Common in African Origin
What is the Pathogenesis of Sickle Cell
HbS polymerises when deoxygenated causing RBCs to deform - producing sickle cells
Sickle Cells - Fragile and Haemolsye, they also occlude small vessels
How do you screen for Sickle Cell in neonates
Hb Electrophoresis
What is the presentation of Sickle Cell
- Anaemia - Cardiomegaly, Low Pulse
- Dactylitis - painful swelling of fingers and toes - often first symptom in babies
- Infarction - low O2 RBC sickle causing pain crises and stroke
- Infection - Asplenia from infarction/damage from abnormal RBC leads to increased risk of life threatening infections and sepsis - any fever is serious!!!!
Sickle Chest Syndrome - pain, fever, cough wheeze,
tachypnoea
- Splenic Sequestration - RBC become blocked in spleen causing spleen to enlarge and become damaged
Chronic Complications: Renal impairment, Splenic Infarction, Retinal disease, Pulmonary HTN and joint damage
What will be found on Ix of Sickle Cell
- HPLC/Hb electrophoresis - HbS - no presence of HbA
- Anaemia
- Film - Sickle Cells
- Raised Reticulocytes
- Raised WCC
How can Sickle Cell be cured
Stem Cell Transplant
What should Sickle Cell patients with a fever do
Seek Help!!
Blood Cultures, CXR
IV fluids, Antipyretics
Hospitalise for any pneumonia
How do you manage pain crisis in sickle cell
Triggered by cold, dehydration, infection
Treat mild with NSAIDs and Parecetamol
Severe: Fluids, Give O2 and Keep warm Blood Transfusion Exchange Transfusion give analgesics e.g. IV morphine
What is Acute Chest Syndome SS commonly caused by how does it present and how is it managed
Infarction or Infection
- Tachypnoea, Chest pain, Fever, Cough, Wheeze
- Admit - IV fluids, blood transfusion, O2 and Abx
What is an Aplastic Crisis caused by in SS
Paravirus B19
How do you treat SS disease
- Hydroxycarbamide
- Transfusion – Prevent strokes for those at highest risk
- Stem cell transplants – In severe cases e.g strokes, severe crisis
What is Thalassaemia
Genetic Disorder resulting in faulty Hb chain synthesis
What is Beta Thalassaemia
Autosomal Recessive - Beta Haemoglobin chains are coded for by two alleles
Thalassaemia Minor - one defective allele (carrier)
Thalassaemia Major - two defective alleles
How does Beta Thalassaemia present
Minor: unremarkable symptoms, may be mildly anaemic
Major:
- Severe haemolytic anaemia
- Growth retardation
- Hepatosplenomegaly
- Skeletal Deformities e.g skull bossing
How do you manage Beta Thalassaemia
Minor: no treatment, maybe iron or folate supplements
Major: • Genetic Counselling • Regular blood transfusion • Iron chelation for iron overload (Liver, Heart, Pancreas) • Bone Marrow Transplantation - cure
How do Haemolytic Anaemias present
- Hydrops fetalis
- Neonatal hyperbilirubinaemia
- Neonatal ascites
- Anaemia/failure to thrive
- Splenomegaly
- Cholecystitis/gall stones
- Hyperbilirubinaemia
- Leg ulcers
- Aplastic crisis
- Thromboembolism
What is Alpha Thalassaemia
Mainly caused by deletion of 4 genes
- All 4 - death in utero
- 3 - moderate anaemia and haemolysis
- 2 - asymptomatic - carrier
- 1 - normal
What is Glucose 6 Phosphate Dehydrogenase Deficiency
X linked chief RBC enzyme defect
mainly effects males
How does G6PD present
• Three main presentations
– Neonatal jaundice
– Chronic non-spherocytic haemolytic anaemia
– Intermittent episodes of intravascular haemolysis
• Sporadic haemolysis
– Typically induced by drugs, fava beans, fever, acidosis
– Intravascular haemolysis - haemoglobinuria, rigors, fever, backpain
– Treated by stopping precipitant, transfusion, renal support
What will see on RBC film of G6PD sporadic haemolysis
Bite and Blister Cells
What is the commonest type of hereditary haemolysis in europeans
Hereditary Spherocytosis - Sphere shaped RBC
What is the commonest type of Immunological Thrombocytopenia
Idiopathic/Immune Thrombocytopenic Purpura - immune destruction of platelets
Can be acute or chronic - usually recovers over weeks or months
When does acute ITP usually occur
In children following a viral infection
How does ITP usually present
Rarely Dangorous, but looks dramatic: Petechiae (tiny purple/brown spots on skin) Mucosal Bleeding Easy bruising Chronic: GI bleeding, nose bleeding
How is ITP treated
• Treatment rarely indicated except TXA
– Occasionally needs treatment with steroids, IV Immunoglobulin or Splenectomy
What are Coagulopathies
Disorders of the clotting cascade
What are two bleeding disorders
Hemophillia
Von Willebands Disease
What is Von Willebands Disease
Deficiency of vWF (von Willeband Factor) leading to: -
- platelet dysfunction (platelets cant stick together)
- Factor VIII Deficiency
How does VW Disease present
Type 1 - AD - mild bleeding can be asymptomatic
Type 2 - AD - moderate bleeding e.g mucosal bleeding from nose and GI and prolonged bleeding after surgery
Type 3 - AR - Severe - Joint and muscle bleeding
How is VW investigated
• History
– often mild bleeding (e.g. bruising, epistaxis, primary
menorrhagia)
• Investigation
– Clotting screen may be normal or APTT increased
– vWF and Factor VIII variably decreased
What is the management of VW
For bleeds/surgery you can give:
– Tranexamic acid
– Desmopressin - can increase vWF and factor VIII
– Severe: Factor VIII/VWF plasma concentrates
What is Haemophillia A and who does it affect
Deficiency of Factor VIII
X linked recessive - affecting males
What is the presentation of Haemophillia A and Haemophillia B
Level <1 - Severe disease - frequent spontaneous prolonged bleeding into muscles and joints leading to deformity and arthritis Neonatal – FHx – Cephalohaematoma/ICH – Iatrogenic bleeding – Umbilical cord bleeding
Early childhood – Classically <2yrs once mobile presents with: • Easy bruising/soft tissue haematomas • Mouth bleeds- often trauma related • Muscle/joint bleeds
Level 1-5 - moderate disease - associated with severe bleeding following injury an occasional spontaneous episodes
Level >5 - mild disease - may present later with bleeding following trauma or surgery/dental extraction
What will be found on investigation of Haemophillia A
Prolonged APTT and low plasma level of Factor VIII
How is Haemophillia A managed
IV infusion of recombinant factor VIII concentrate
What is Haemophillia B
Deficiency of Factor IX
X linked recessive affecting males
What will be found on investigation of Haemophillia B
Raised APTT and low plasma level of Factor IX
How is Haemophillia B managed
IV infusion of recombinant Factor IX concentrate
What is Diamond Blackfan Anaemia and how does it present
physical anomalies- at least 50% • Cranio-facial • thumb 10-20% • Deafness • Musculoskeletal • Renal • Cardiac • Growth retardation
What are some causes of Hypercoagulation
antithrombin, protein C, protein S, FVL, PT mutation, APS
How do you diagnose thalassaemia
Blood Sample: microcytic hypochromic anaemia
Hb Electrophoresis: reduced/absent HbA , elevated HbA2 and increased levels of HbF
DNA analysis
