Haematology Flashcards
What are the three most common causes of anaemia globally?
IDA
Vitamin A deficiency
Beta-Thalassaemia
How is anaemia diagnosed?
FBC
Haemo-cue
Hb Colour Scale
Blood Film
How much of the global population is affected by IDA?
20-50%
Probably 40-45% in LMICs
3rd leading cause of morbidity in pregnancy
What are the most common cause of IDA in LMICs?
Bacteraemia
Marlaria
Hookworm infectoin
HIV
G6PD
Vit A/B12 deficiency
What are classic clinical symptoms of IDA?
Koilonychia
Angular Stomatitis
Pale
How much of dietary iron can be absorbed in the gut each day?
3.5mg/day
How soon should Hb improve after Iron supplementation
0.5-1g/dL per week
How is IDA diagnosed?
- Blood Film: Hypochromic, microcytic, pencil cells (same picture as thalassaemia)
- FBC: Anaemia, low MCV, low MCH
- Fe in Bone Marrow aspirates
How is IDA managed?
Ferrous Sulphat 200mg TDS
What are the main risk factors for folate deficiency
Poor diet
ETOH abuse
Chronic Haemolytic anaemias
What are the clinical symptoms of folate deficiency?
Anorexia
Altered bowel habit
Glossitis
What does a blood film show in folate deficiency
Hypersegmented neutrophils, macrocytic
How do you managed folate deficiency?
5mg folic acid daily for at least 3/12
What autoimmune condition causes b12 deficiency
Pernicious Anaemia
What are neurological symptoms of B12 deficiency?
Posterolateral column degeneration
Low mood
Poor memory and cognition
Peripheral neuropathy
Optic nerve atrophy
How is B12 deficiency managed?
Hydroxycobalamin injections
1mg monthly
What are the three most common haemolytic anaemias?
- SCD
- G6PD deficiency
- Thalassaemia
What are the three cardinal signs/symptoms of of haemolytic anaemia?
Jaundice
Anaemia
Dark ‘coca cola’ urine
What are the lab findings in haemolytic anaemia?
Low Haemoglobin
high unconjugated bilirubin
Polychromasia
What is the epidemiology of Sickle Cell Disease?
Follows area with high malaria transmission
Greatest burden in:
- Nigeria
- Ghana
- Central Africa
- Saudi Arabia
- India
What is the pathophysiology of SCD?
B-globulin mutation –> destruction of the structure of RBCs, making them prone to destruction in times of altered O2 tension
RBCs become rigid and ‘sickled’ and cannot fit through normal blood vessels. This leads to an accumulation of cells within blood vessels, creates microthrombi etc.
There is also chronic haemolysis of the sickled RBCs
What is the genetic cause of SCD?
Autosomal Recessive
HbSS
What is the presentation of SCD?
Haemolytic Anaemia
BM expansion –> frontal bossing and maxillary enlargement
Stunting
Dactylitis
What are the complications of SCD?
Splenic Sequestrtion
Aplastic Crises
Stroke
Acute Chest Syndrome of SCD
osteomyeltis
Infection/Sepsis
Pain Crisis
How is SCD diagnosed?
- Neonatal screening (has reduced child mortality by 95%)
- FHx
- Blood Film –> sickled cells (Up to 80% will be sickled in HbSS)
- Hb Electrophoresis
- Sickle solubility test
- Genetic testing
How do you generally manage SCD?
- Folic acid supplementation
- Regular penicillin-based prophylactic antibiotics (at risk of encapsulated bacterial invasion)
- Hydroxycarbamine
What are 5 common encapsulated bacteria implicated in SCD infections?
Streptococcus pneumoniae
Klebsiella
Haemophilus influenzae
Neisseria meningitidis
Pseudomonas aeruginosa
How does hydroxycarbamine aide in preventing complications of SCD?
Increased the production of HbF (which can replace HbS)
What vaccinations should be given to patients with SCD?
- Pneumococcal
-HiB - Meningococcal
- Influenza
Who should be offered splenectomy in SCD?
Offer in patients with multiple episodes of Splenic sequestration before the age of 5
What is Beta Thalassaemia?
Haemolytic Anaemia caused by a reduction in Beta Globulin
What are the three types of Beta Thalassaemia?
- B Thal. Trait –> clincially well, with normal Hb in physiological steady states
- B Thal intermedia –> generally stable, but chronically low Hb of 70-80, which may require occasional Blood transfusions
- B Thal Major –> Significantly dysmorphic cells, with Hb of 20-30 without regular blood transfusions
What is the epidemiology of Beta Thalassaemia?
- Most common haemolytic anaemia
- Mediterranean Basis, South East Asia
What is the presentation of Beta Thal?
Haemolytic anaemia
Frontal bossing, maxillary widening
Hepato-splenomegaly
How is Beta Thal diagnosed on blood film?
- Hypochromic, microcytic RBCs, Target cells, polychromatic RBCs
How is beta thal managed?
Regular blood transfusions
Iron chelation
What are the two drugs that can be used in iron chelation?
- IV desferrioxamine (expensive)
- PO deferiprone
What is G6PD?
A compound in RBCs which prevents them from haemolysing prematurely in the presence of oxidative stress
What is G6PD deficiency?
An inherited condition in which there is not enough G6PD in RBCs, leading to haemolytic anaemia from red cell oxidation
How is G6PD genetically passed on?
X-linked
Where is G6PD deficiency most common?
Mediterranean Basin
African continent
What is the presentation of G6PD Deficiency?
Neonatal jaundice ± kernicterus
What drugs can percipitate haemolysis in G6PD-D?
Aspirin
Primaquine
Dapsone
Sulfonamides
Nitrofurantoin
What does a blood film look like in G6PD?
Bite Cells
Helmet Cells
How is G6PD-D diagnosed?
- Blood Film
- Methaemoglobin reduction test
- Enzyme assay –> should be done 6-8 weeks after haemolytic episode
How is G6PD-D managed?
Usually self limiting
± transfusion
± renal support
What does a blood film in IDA look like?
Blood Film: Hypochromic, microcytic, pencil cells (same picture as thalassaemia)
