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Medicine - Year 2 > The haematological system and skin - Anaemia and red cell metabolism and transfusion > Flashcards

The haematological system and skin - Anaemia and red cell metabolism and transfusion Flashcards

1
Q

Which groups are most vulnerable of Iron deficiency?

A

Women of child-bearing: because of menstrual blood losses and pregnancies

Children: Because of increased requirements for iron to meet growth (muscles, tissues, and commencement of period in girls)

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2
Q

a) Symptoms

b) Signs

A

a)
- Tiredness
- Weakness
- Pale skin
- Fast or irregular heartbeat
- SOB
- Chest pain
- Dizziness
- Cognitive problems
- Numbness or coldness in extremities
- Headache
- Restless legs syndrome
- Failure to thrive in infant
- Growth retardation in children

b)
- Bounding pulse
- Postural hypotension
- Tachycardia
- Conjunctival pallor
- Shock

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3
Q

Sources of iron in the diet

A
  • Cereals
  • Meat
  • Vegetables
  • Dairy
  • Eggs
  • Fish
  • Chocolate
  • Beverages
  • Alcoholic beverages
  • Soups, sauces, pickles
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4
Q

Risk factors of iron deficiency anaemia

A
  • H.pylori infection
  • Long-terms use of PPIs
  • Blood loss: high menstrual losses, frequent blood donation
  • Pregnancy
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5
Q

Explain dietary factors that explain iron deficiency in industrialised countries

A
  • Low bioavailability
  • Sedentary lifestyles
  • Low micronutrient density (Highly processed foods contain more fat and sugar (‘empty calories’) than unprocessed foods)
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6
Q

How much red or processed meat is recommended by the UK government?

A

The UK government recommends no more than 70g of red or processed meat

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7
Q

Describe the function of Vitamin B12

A
  • Development, myelination, function of CNS
  • RBC formation, DNA synthesis
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8
Q

Describe the causes of B12 deficiency

A

Primary cause - impaired absorption of vitamin B12 (pernicious anaemia) resulting from a lack of intrinsic factor

Other causes of vitamin B12 deficiency include:

  • Inadequate dietary intake of vitamin B12 e.g., vegan diet
  • Gastric-related causes e.g., gastrectomy, gastric resection, atrophy gastritis, H.pylori infection
  • Long-term use of drugs that affect gastric production (e.g., H2 receptor antagonists, PPIs) can worsen deficiency because gastric acid is needed to release B12 bound to proteins in food
  • Intestinal causes e.g., malabsorption, ileal resection, Crohn’s disease affecting the ileum, chronic tropical sprue, HIV, and radiotherapy
  • Drugs e.g., colchicine, neomycin, metformin, anticonvulsants
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9
Q

Consequences of vitamin B12 deficiency

A
  • Neural tube defects
  • Stroke
  • Dementia
  • The brain is particularly; in children, inadequate B12 stunts brain and intellectual development
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10
Q

Dietary sources of B12

A

Products of animal origin
- Meat (especially liver)
- Poultry
- Fish
- Milk and dairy products
- Eggs

Fortified breakfast cereals

Fermented food e.g., sauerkraut

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11
Q

Describe the NICE guidelines for treatment of B12 deficiency

A

Advise people to eat foods rich in vitamin B12.

Foods which have been fortified with vitamin B12 (E.g., some soy products, breakfast cereals and breads) are good alternative sources to meat, eggs, and dairy products

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12
Q

Describe the role of folate and folic acid

A
  • RBC formation
  • Cell growth and function
  • Works with B6 and B12 to control elevated blood homocysteine
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13
Q

Good dietary sources of folate

A
  • Liver
  • Yeast extract
  • Green leafy vegetables
  • Legumes (beans, lentils)
  • Orange juice
  • Fortified cereals
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14
Q

At risk groups of folate deficiency

A

Children 11-18 years old

Women of child-bearing age

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15
Q

Describe a strategy made in the UK to deal with flic acid deficiency

A

in sept 2021, folic acid fortification of flour made mandatory in the UK to prevent spinal conditions in babies

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16
Q

What is is the controversy over safety of folic acid

A

There is a risk that if folic acid is given to people with undiagnosed deficiency of Vitamin B12 it may lead to neurological damage

This is because folic acid will correct the anaemia of Vitamin B12 deficiency and so delay diagnosis but will not prevent progression to neurological damage

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17
Q

Describe the NICE guidelines for treatment of folate deficiency

A

Give dietary advice: good sources of folate are broccoli, Brussel sprouts, asparagus, peas, chickpeas, and brown rice

Prescribe oral folic acid 5mg daily

Check vitamin B12 levels in all people before starting folic acid, as treatment can improve well-being such that it can mask underlying B12 deficiency and allow neurological disease to develop

In most people, treatment will be required for 4 months. However, folic acid need to be take for longer (sometimes for life), if the underlying cause of deficiency is persistent

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18
Q

Vulnerable groups in nutritional anaemia

A
  • Infants and children (iron deficiency)
  • Vegans (iron and B12 deficiency)
  • Pregnant women (iron and folate deficiency)
  • Elderly (iron, folate and B12 deficiency)
  • Low income
  • Ethnic minorities
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19
Q

Why may iron and B12 deficiency occur in children?

A
  • Prolonged breast or bottle feeding may lead to iron/ B12 deficiency
  • If weaning foods have a low iron/B12 content
  • Vegan children
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20
Q

State the factors that make elderly patient at high risk of anaemia

A
  • Higher risk of nutritional deficiencies
  • Impaired absorption (particularly vitamin B12)
  • Dental problems - restricted food choice
  • Poor quality meals in institutions
  • Lower socioeconomic status
  • Less mobile - restricted shopping
  • Mental problems - dementia, depression
  • Lower physical activity requires lower energy intake
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21
Q

Causes of iron deficiency

A

Inadequate diet

Increased requirements
- Pregnancy
- Growth

Malabsorption

Blood loss
- Menstrual
- GI
- Urinary
- Lung

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22
Q

Laboratory findings of iron deficiency anaemia

A
  • Microcytic hypochromic anaemia
  • Serum ferritin reduced, serum iron low, raised transferrin and reduced saturation of iron building capacity
  • Raised platelet count
  • Blood film appearances: hypochromic/microcytic cells, anisocytosis/poikilocytosis, target cells and ‘pencil’ cells
  • Bone marrow (not need for diagnosis): erythroblasts show ragged irregular cytoplasm; absence of iron from stores and erythroblast
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23
Q

Gi investigations in iron-deficiency anaemia

A

Faecal haemoglobin (FIT) - sensitive test for blood in stools

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24
Q

GI causes of iron deficiency anaemia

A
  • Hookworm infections
  • Oesophago-gastric cancer
  • Coeliac disease
  • Crohn’s disease
  • Gastritis
  • Peptic ulceration
  • Oesophagitis
  • Gastrectomy
  • NSAID enteritis
  • Meckel’s diverticulum
  • Colon cancer - Especially right sided
  • Large polyps
  • Colitis
  • Angiodysplasia
  • Diverticular bleeding
  • Haemorrhoids
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25
Q

Describe the main treatment of iron deficiency anaemia

A

Oral iron - ferrous sulphate for 3 months before meals 3x daily

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26
Q

Name 3 other preparations of iron replacement therapy

A
  • Ferrous gluconate
  • Sodium ironedate
  • Ferric maltol
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27
Q

a) Side effects of iron replacement therapy e.g., ferrous sulphate

b) What should you do if patient experiences these symptoms?

A

a) Abdominal pain, diarrhoea or constipation

b) Lower dose or a different preparation

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28
Q

When should you consider parenteral iron over oral iron?

A

If absorption impaired

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29
Q

Macrocytic anaemia - megaloblastic causes

A
  • B12 deficiency
  • Folate deficiency
  • Combine deficiency
  • Abnormal folate metabolism: methotrexate
  • Abnormal DNA synthesis: Orotic aciduira, azathioprine, Zidovudine
  • Myelodysplasia
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30
Q

Macrocytic anaemia - non-megaloblastic causes

A
  • Just macrocytosis
  • Pregnancy
  • Liver disease
  • Alcoholism
  • Reticulocytotic
  • Hypothyroidism
  • Drugs
  • Marrow infiltration
  • Sideroblastic anaemia
  • Cold agglutinins
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31
Q

Causes of folate deficiency

A

Diet
- Anorexia
- Children
- Elderly
- Alcoholics

Increased utilisation
- Physiological: Pregnancy and growth
- Pathological: Haemolysis, cancers, inflammation

Malabsorption
- Diffuse small bowel disease

Urinary loss
- Haemodialysis

Drugs
- Phenytoin
- Primidone
- Sulfasalazine and related
- Methotrexate

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32
Q

Describe the treatment of folate deficiency

A

5mg oral folic acid daily for 4 months or continuously

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33
Q

Which patients should you provide folic acid as prophylaxis

A
  • Pregnancy and preconception
  • Haemolysis
  • Methotrexate therapy
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34
Q

a) What is pernicious anaemia

b) What is the management?

A

a) Lack of intrinsic factor production leads to less absorption of vitamin B12 and so causes vitamin B12 deficiency

b) IM Vitamin B12 (cobalamin) replacement

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35
Q

Haemolytic anaemia

a) Symptoms

b) Signs

A

a)
- Fatigue
- Weakness
- Paraesthesia
- Dyspnoea
- GI symptoms (e.g., nausea, dyspepsia)
- Weight loss

b)
- Jaundice
- Drak urine
- Abdominal pain
- Atrophic glossitis
- Pallor
- Fever
- Splenomegaly

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36
Q

Investigations/Laboratory findings in haemolytic haemolysis

A

RBC - anaemia (normocytic or macrocytic)

Reticulocyte count - raised

Blood film - typical morphologies of associated with haemolysis which includes spherocytes, schistocytes, sickle cells

LDH - raised

LFTs (bilirubin) - raised

Serum haptoglobin - low

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37
Q

Inherited causes of haemolytic anaemia

A

Membrane defects
- Hereditary spherocytosis
Elliptocytosis

Enzyme defects
- G6PD deficiency
- Pyruvate kinase deficiency

Haemoglobinopathy
- Sickle cell disease
- Thalassaemia

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38
Q

Acquired causes of haemolytic anaemia

a) Immune mediated

b) Non-immune mediated

A

a)
Alloimune haemolysis
- Haemolytic disease of newborn
- Haemolytic transfusion reaction

AIHA
- Warm AIHA
- Cold AIHA

b)
- Mechanical trauma
- Microangiopathic haemolytic anaemia (MAHA): HUS, TTP, DIC
- Infections
- Renal disease
- Drugs and chemicals
- Hypersplenism

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39
Q

Name membrane defects that cause haemolytic anaemia

A

Hereditary spherocytosis

Hereditary elliptocytosis

Hereditary stomatocytosis

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40
Q

Pathophysiology of inherited membrane defects e.g., hereditary spherocytosis

A

RBC cannot maintain biconcave shape

In these conditions RBC is more easily damaged and removed by macrophages (so shorter half life of RBC)

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41
Q

Inheritance of hereditary sperocytosis

A

Autosomal dominant

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42
Q

Clinical features of inherited RBC membrane defects

A
  • Cause of prolonged neonatal jaundice
  • Mild anaemia presenting at any age
  • Jaundice fluctuant
  • Gallstones
  • Aplastic crises precipitated by parovirus
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43
Q

Investigations for inherited RBC membrane defects

A
  • Family history
  • Blood film
  • Haemolysis screen: FBC, reticulocytosis, LDH, billirubin
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44
Q

Laboratory findings of inherited RBC membrane defects

A
  • Anaemia (usually mild)
  • Reticulocytosis
  • Bilirubin raised
  • LDH raised
  • Blood film shows abnormally shaped RBC
  • Direct Coombs test negative
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45
Q

Treatment of inherited RBC defects

A

Folic acid

Splenectomy (in severe cases of HS)

Cholecystectomy (+ splenectomy) - pigment gallstones may cause cholecystitis

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46
Q

Inheritance of G6PD deficiency

A

X-linked recessive

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47
Q

Epidemiology of G6PD deficiency

A

Common in black (Africa), Mediterranean, Middle Eastern and oriental population

Usually seen in areas with a high prevalence of malaria

Predominantly male

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48
Q

Pathophysiology of G6PD deficiency

A

G6PD produces NADPH which is required for (reduced glutathione) regeneration

Glutathione rapidly inactivates oxidants that can damage RBC

When patients with G6PD are exposed to a variety of oxidants, they are rapidly depleted of glutathione

This leads to oxidation of numerous proteins in RBC that alters and renders them susceptible to break down (haemolysis) by macrophages

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49
Q

Role of G6PD

A

To prevent oxidative stress in RBC

This is by producing NADPH which is required for (reduced) glutathione regeneration.

Glutathione inactivates oxidants that can
damage RBC

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50
Q

Precipitants of G6PD deficiency

A

Drugs
- Antibiotics: nitrofurantoin, fluoroquinolone, sulphonamides
- Antimalarials: primaquine, chloroquine (possible), quinine (possible)
- Other: Dapsone, Methylene blue, Sulfonylureas, Rasburicase

Food
- Fava beans

Infections

Moth balls

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51
Q

Clinical features of G6PD deficiency

a) Symptom

b) Signs

A

a)
- Lethargy
- Dizziness
- SOB
- Jaundice
- Dark urine
- Abdominal/back pain

b)
- Pallor (anaemia)
- Jaundice
- Splenomegaly

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52
Q

Diagnosis of G6PD deficiency

A

Assessment of G6PD enzyme activity

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53
Q

Who do you test for G6PD deficiency?

A

Patients with unexplained haemolytic anaemia

Babies with neonatal jaundice

Patients on medications that is down to precipitate haemolysis in G6PD deficiency

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54
Q

Laboratory features of G6PD deficiency

A

FBC - anaemia and macrocytosis

Blood film - Heinz bodies, may show fragments due to haemolysis

Reticulocyte count - raised

LFTs (bilirubin) - raised

Haptolglobin - reduced

Coombs test - negative

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55
Q

Management of G6PD deficiency

A
  • Avoidance of precipitants of oxidative injury
  • Treat infection if present
  • Transfuse RBC if necessary (in severe anaemia)
  • Folic supplementation (in severe anaemia)
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56
Q

Thalassaemia - definition

A

Reduced/no alpha or beta chains produced

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57
Q

Alpha thalassaemia - definition

A

Reduced/no alpha chains produced

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58
Q

Beta thalassaemia - definition

A

Reduced/no beta chains produced

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59
Q

Thalassaemia major - definition

A

No alpha/beta chains

60
Q

Thalassaemia strain - definition

A

Reduce alpha/beta chains person is asymptomatic

61
Q

Beta thalassemia clinical features

A

Severe anaemia from 3-6 months

Failure to thrive, intercurrent infection, pallor, mild jaundice

Liver and spleen enlargement

Skeletal changes
- Thalassaemic facies
- Osteoporosis/osteopenia
- Body habits changes: typically, short limbs (due to early fusion of epihyses)
- Skull (frontal bossing), pelvis, ribs, and spinal changes may be seen
- Bony pain

Disorders associated with iron overload
- Growth impairment
- Hepatic impairment
- Cardiac failure
- Cardiac arrhythmias
- Joint symptoms
- Hyper-pigmented appearance
- Endocrine disorders: hypogonadism and hypothyroidism and diabetes mellitus

Other abnormalities
- Pulmonary: obstructive and restrictive defects
- Thrombosis
- Leg ulcers

62
Q

Alpha thalassaemia major: Haemoglobin Barts definition

A

Four alpha genes are inactive

63
Q

Alpha thalassaemia major: Haemoglobin Barts - consequence

A

Four alpha genes are inactive, which is incompatible with extrauterine life

Leads to hydros fetalis (Fatal in utero due to severe anaemia, high-out cardiac failure and generalised oedema)

64
Q

Alpha thalassaemia major: Haemoglobin H (HBH) - definition

A

Deletion or functional inactivity of 3/4 alpha genes

65
Q

Alpha thalassaemia major: Haemoglobin H (HBH) - clinical features

A

Variable phenotype from mild affected to requiring life-long blood transfusions

Bone deformities and features of iron overload do not usually occur

Pallor

Ananemia

Jaundice

Gallstone disease

Extramedullary haematopoiesis: hepatosplenomegaly, skeletal changes

Osteopenia/osteoporosis

Aplastic/hyoplastic crisis

Leg ulcers

66
Q

Thalassaemia trait - clinical features

A

Mild microcytic anaemia

Asymptomatic

67
Q

Thalassaemia - screening protocals

A

Screening for thalassaemia is offered to all pregnant women within the uK

68
Q

Advise to parents who have alpha thalassaemia with 2/4 genes deleted?

A

There is a risk of conceiving a foetus with no alpha genes leading to hydrops fetalis

69
Q

Thalassaemia laboratory findings

A

FBC - anaemia, low mCV

Blood film - hypochromic, microcytic

LFTS (unconjugated bilirubin) - raised

Haemolysis screen - LDH raised, haptoglobin reduced, Coombs test negative

Hb electrophoresis / Hyper performance liquid chromatography - absence HbA (beta thalassaemia major) / increased HbA2 (beta thalassaemia trait)

Genetic analysis - for alpha that

70
Q

Diagnostic testing for beta thalassaemia

A

Hb electrophoresis

71
Q

Diagnostic testing for alpha thalassaemia

A

Genetic analysis

72
Q

Diagnostic findings of beta thalassaemia major in Hb electrophoresis

A

Absence HbA

73
Q

Diagnostic findings of beta thalassaemia trait in Hb electrophoresis

A

Increased HbA

74
Q

Management of thalassaemia major

A

Lifelong transfusions (every 3-4 weeks)

Splenectomy

Allogenic bone marrow transplantation

Treat iron overload with iron chelation

Beta thalassaemia: treat osteoporosis with bisphosphonates and Vitamin D and calcium

75
Q

Management of thalassaemia treatment

A

Asymptomatic - do not need treatment

Avoid iron unless iron deficient

Genetic counselling

76
Q

Genetic inheritance of sickle cell disease

A

Autosomal recessive

77
Q

Sickle cell disease - pathophysiology

A

Point mutations leads to single amino acid substitution of valine to glutamate at position 6 in beta chain. This forms HbS

HbS forms crystals when exposed to low oxygen levels - causes ‘sickling’ of RBC

This damages RBC leading to chronic haemolysis

Clustering results in blood vessel occlusion

78
Q

Give 3 types of crises in sickle cells disease

A

Vaso occlusion

Visceral sequestration

Aplastic crisis

79
Q

Vaso-occlusion in sickle cell disease - pathophysiology

A

Due to shape and stickiness, sickle cells can occlude capillaries and cause infarction of tissue supplied by that blood vessel

80
Q

Vaso-occlusion in sickle cell disease - consequences

A

Acute painful episodes

Acute chest syndrome

Renal infarction

Bone infarction or dactylitis

Myocardial infarction

Stroke

Venous thromboembolism

Priapism (persistent, painful erection)

81
Q

Visceral sequestration in sickle cell disease - pathophysiology

A

Caused by sickling with pooling of red cells in the liver, spleen or lung

82
Q

Aplastic crisis in sickle cell disease - pathophysiology

A

Occurs following infection by B19 Parovirus

This causes temporary arrest for erythropoiesis (virus prevents RBC production)

In health individuals there is no consequence as lifespan of RBC is 120 days

Due to reduced red cell survival in sickle cell 910-20 days) this can rapidly cause severe anaemia (requiring blood transfusion)

83
Q

Sickle cell disease - clinical features

A

Anaemia

Increased susceptibility to infections

Vaso-occlusive phenomenon

Acute painful episodes

Acute chest syndrome: fever, chest pain, hyperaemia, wheezing, cough, respiratory distress

Chronic complications
- Neurological: stroke and seizure disorders
- Blood: chronic anaemia
- Bone: osteoporosis and avascular necrosis
- Cardiac: cardiomyopathy and heart failure
- Pulmonary: pulmonary hypertension
- Kidneys: CKD
- Liver: liver damage from iron overload, gallstones
- Others: chronic pain, delayed puberty, leg ulcers and retinal disease

84
Q

Acute chest syndrome in sickle cell disease - definition

A

New radiodensity on chest imaging accompanied by fever and/or respiratory symptoms.

85
Q

Acute chest syndrome in sickle cell disease - clinical features

A

fever, chest pain, hyperaemia, wheezing, cough, respiratory distress

86
Q

Sickle cell disease: chronic complications

A

Neurological: stroke and seizure disorders

Blood: chronic anaemia

Bone: osteoporosis and avascular necrosis

Cardiac: cardiomyopathy and heart failure

Pulmonary: pulmonary hypertension

Kidneys: CKD

Liver: liver damage from iron overload, gallstones

Others: chronic pain, delayed puberty, leg ulcers and retinal disease

87
Q

Sickle cell disease - laboratory features

A

FBC: mild anemia

Haemolysis screening: raised LDH, raised bilirubin, low haptoglobin

Blood film - sickle cells and Howell-jolly bodies (hyposplenism)

Sickle solubility screen - positive

Hb electrophoresis/Hyper performance liquid chromatography - HbS, no HbA, variable amounts of HbF

88
Q

Describe findings of sickle solubility screen in sickle cell diseases

A

Sickle solubility screen - positive

HbS less soluble when reduced

89
Q

Sickle cell disease - Hb electrophoresis/Hyper performance liquid chromatography

A

Shows hbS, no HbA, variable amounts of HbF

90
Q

Sickle cell disease - screening protocols

A

Newborn screening - involves a blood spot sample (typically heel prick) that is taken on day 5 of life

91
Q

Sickle cell disease - prophylactic management

A

Prophylactic
- Patient education
- Avoid precipitating factors
- Folic acid
- Pneumococcal vaccine; regular oral penicillin
- Stroke prevention: transcranial doppler ultrasound is perfumed annually between 2-16 years of age to determine risk of stroke

Crises
- Analgesia (opiates), rest, rehydration, oxygen +/- antibitocis
Blood transfusion
Exchange transfusion

Oral hydroxycarbamide

Crizanlizumab

Stem cell transplantation

Joint replacement surgery for avascular necrosis

Iron chelation - prevent iron overload

92
Q

Sickle cell trait - clinical features

A

No/mild anaemia

93
Q

Sickle cell trait - management

A

Genetic counselling

Advice that acre should be taken during anaesthesia and high altitudes (hypoxia can rarely cause sickling)

94
Q

Warm autoimmune haemolytic anaemia - definition

A

Antibodies (IgG) attack RBC at 37 degrees degrees

95
Q

Cold autoimmune haemolytic anaemia

A

Antibodies (IgM) attack RBC below 37 degrees celsius

96
Q

Warm autoimmune haemolytic anaemia - antibody associated

A

IgG

97
Q

Cold autoimmune haemolytic anaemia - antibody associated

A

IgM

98
Q

Warm auto immune haemolytic anaemia - Causes

A

Idiopathic

Secondary
- Autoimmune conditions e.g., SLE
- Disordered immune system e.g., CLL, low grade lymphoma
- Drugs e.g., penicillin, methldopa

99
Q

Cold haemolytic anaemia - causes

A

Idiopathic

Secondary
- Lymphoma
- Infections: mycoplasma pneumonia, EBV
- Paroxysmal cold haemoglobinuria

100
Q

Autoimmune haemolytic anaemia - laboratory findings

A

FBC: anaemia

Reticulocytes: raised

LDH: raised

LFTs (unconjugated bilirubin): raised

Blood film: spherocytes in warm haemolytic anaemia; schistocytes and agglutination in cold AIHA

Direct antiglobulin test (DAT)/Coombs: positive

101
Q

Autoimmune haemolytic anaemia - blood film findings

A

Spherocytes in warm haemolytic anaemia;

Schistocytes and agglutination in cold AIHA

102
Q

Warm autoimmune haemolytic anaemia - management

A
  • Remove or treat underlying cause
  • Corticosteroids e.g., prednisolone emg/kg orally with subsequent gradual reduction
  • Other immunosuppressive drugs e.g., rituximab, azathioprine, ciclosporin, cyclophosphamide, mycophenolate
  • Blood transfusion if necessary
  • Consider splenectomy if steroid and immunosuppressive drug therapy fails
  • Folic acid
103
Q

Cold autoimmune haemolytic anaemia - management

A
  • Keep the patient warm
  • Consider immunosuppression: corticosteroids, rituximab
  • Consider plasma exchange to lower antibody tire
  • Folic acid
104
Q

Thrombotic thrombocytopenia purpura - pathophysiology

A

There is a deficiency of ADAMTS13 (metalloprotease enzyme) which normally breaks down large multimers of vWF

Abnormally large and sticky multimers of vWF causes platelets to clump within vessels leading to shearing of RBCs in vessels

105
Q

Thrombotic thrombocytopenia purpura - Investigations

A

FBC

Blood film

Reticulocyte count

LFTs: Unconjugated bilirubin

LDH

DAT (Coombs)

Virology screen

ADAMTS13 assay

106
Q

Thrombotic thrombocytopenia purpura - treatment

A
  • Plasma exchange using fresh from plasma
  • Antiplatelet drugs
  • Corticosteroids
  • Splenectomy
  • Rituximab
107
Q

Thrombotic thrombocytopenia purpura - clinical features (classic pentad)

A

Pentad of:

  1. Thrombocytopenia
  2. Neurological impairment
  3. Fever
  4. Renal impairment
  5. Microangiopathic haemolytic anaemia
108
Q

Disseminated intravascular coagulation - pathophysiology

A

Occurs when the balance between the formation of new clots (coagulation) and the breakdown of clots (fibrinolysis) is tipped in favour of coagulation.

It causes widespread clot formation and tissue ischaemia whilst also using up platelets and clotting factors, leading to excess bleeding.

109
Q

Disseminated intravascular coagulation - clinical features

A
  • Purpura
  • Ecchymoses
  • GI bleeding
  • Bleeding from IV sites and venepuncture may occur
  • Impaired renal function
  • ARDS
  • Adrenal necrosis
  • Shock
  • Thromboembolism
110
Q

Disseminated intravascular coagulation - laboratory features

A
  • Thrombocytopenia
  • raised D-dimer
  • low platelets
  • low fibrinogen
111
Q

Disseminated intravascular coagulation - management

A
  • Treat underlying cause
  • Fresh frozen plasma
  • Platelet concentrated and cryoprecipitate if bleeding is dominant
  • Anticoagulant therapy if thrombosis is dominant
112
Q

Haemolytic uremic syndrome - main cause

A

Occurs in children and 90% of cases in children are caused by E-coli which produces a shiga-like toxin

113
Q

Haemolytic uremic syndrome - clinical features (classic triad)

A

AKI

Microangiopathic haemolytic anaemia

Thrombocytopenia

114
Q

Haemolysis - Infectious cause

A

Malaria

115
Q

Haemolysis - chemical and physical agent cause

A

Drugs - e.g., dapsone

Cooper

Lead

Burns

Snake and spider bites

116
Q

Paroxysmal nocturnal haemoglobinuria (PNH) - pathophysiology

A

Acquired defect of marrow stem cells that leads to defect in anchorage of surface proteins because of absence of GPI (glycosylphosphatidylinositol)

GPI prevents lysis of RBC therefore in PNH, RBC is rendered sensitive to lysis by complement

117
Q

Paroxysmal nocturnal haemoglobinuria (PNH) - Clinical features

A
  • Patients present early adulthood with nocturnal episodes of intravascular haemolysis
  • Dark urine
  • Increased risk of clot formation, particularly at unusual sites e.g., hepatic veins
118
Q

Paroxysmal nocturnal haemoglobinuria (PNH) - management

A
  • Eculizumab - reduce haemolysis, thrombosis, and improve life expectancy
  • Transfusion of leucodepelted RBC may be necessary
  • Warfarin may be needed to prevent thrombosis
  • Allogenic stem cell transplant (severe cases)
119
Q

Microcytic anaemia - causes

A

Thalassaemia

Anaemia of chronic disease

Iron-deficiency anaemia

Lead positioning

Sideroblastic anaemia

120
Q

Normocytic anaemia - causes

A

Anaemia of chronic disease

Acute blood loss

Chronic renal failure

Mixed B12/folate and iron deficiency

Bone marrow disorders

121
Q

Macrocytic anaemia - causes

A

B12/folate deficiency

Liver disease

Drugs inc. alcohol

Reticulocytosis (haemolysis)

Hypothyroidism

Myelodysplasia

Pregnancy

122
Q

Sideroblasic anaemia - pathophysiology

A

Occurs due to ineffective erythropoiesis, resulting in increased iron absorption and deposition within the bone marrow

123
Q

Sideroblastic anaemia - clinical/laboratory features

A

Microcytic anaemia refractory to intensive iron therapy

Atypically high serum ferritin and iron

124
Q

Acute haemolytic transfusion - commonest cause, clinical features and management

A

Commonest cause - ABO incompatibility

Clinical features - fever, hypotension, anxiety, red-coloured urine. DIC

Management - stop transfusion, supportive care e.g., blood pressure support, hydration combined with diuretics to increase urine output

125
Q

Delayed transfusion reaction (more than 24 hours post transfusion)

A
  • Delayed haemolytic transfusion reaction
  • Transfusion associated graft v host disease
  • Post transfusion pupura
126
Q

Febrile non haemolytic transfusion reaction: clinical features and management

A

Clinical features
- At the end of transfusion or up to 2 hours afterwards
- Fever

Management
- Stop transfusion
- Treat fever with antipyretic

127
Q

Allergic reaction (anaphylaxis) transfusion reaction - clinical features and management

A

Clinical features
- Itchy rash
- Angioedema
- Shortness of breath
- Vomiting
- Light headedness
- Hypotension

Management
- Stop transfusion
- Administer adrenaline

128
Q

Bacterial contamination transfusion reaction - clinical features and management

A

Clinical features
- Rapid severe pyrexia

Management
- Stop transfusion
- Oxygen
- Diuretics

129
Q

Transfusion associated circulatory overload (TACO) - Clinical features and management

A

Clinical feature
- With 12 Horus of transfusion
- Bipedal oedema
- Bibasal crackles on auscultations

Management
- Stop transfusion
- Oxygen
- Diuretics

130
Q

Transfusion related acute lung injury (TRALI) - Clinical features and management

A

Clinical features
- Occurs within 6 hours of transfusion
- Respiratory symptoms: dyspnoea, cough, ARDs

Management
- Stop transfusion
- Respiratory support
- Supportive care and monitoring
- Inform blood bank and haematology

131
Q

Transfusion related acute lung injury (TRALI) - CXR changes

A

“white out”

132
Q

Delayed haemolytic transfusion reaction - laboratory findings, clinical features and management

A

Laboratory findings
- Low Hb
- High bilirubin

Clinical features
- Within 1-4 days of transfusion
- Fever
- Jaundice
Hameglobinuria

Management
- Stop transfusion
- IVIg and steroids

133
Q

Transfusion associated graft v host disease - clinical features and management

A

Clinical features
- Within 1-2 weeks of transfusion
- Flue like illness
- Rapidly develops into multi organ failure

Management
- Supportive
- Immunosuppressants

134
Q

Post transfusion purpura - cause, clinical features and management

A

Causes
- Occurs when the body produces alloantibodies to the introduced platelets antigens

Clinical features
- 5-9 days post transfusion
- Thrombocytopenia
- Purpura

Management
- Usually self limited
- IV Ig

135
Q

Acute transfusion reaction (up to 24 hours post transfusion) - types

A
  • Febrile non haemolytic transfusion reaction
  • Allergic reaction (anaphylaxis)
  • Acute haemolytic transfusion reaction
  • Transfusion associated circulatory overload (TACO)
  • Transfusion related acute lung injury (TRALI)
136
Q

How is the risk of transfusion associated graft vs host disease prevented?

A

Irradiated blood/blood product

137
Q

Indications of irradiated blood/blood products - lifelong and temporary

A

Lifelong
- Hodgekin’s disease
- Fludarabine, Bendamustine or Alemtuzumab
- Congenital immunodeficiency state

Temporary
- Stem cell harvest
- Autologous transplant
- Allogenic transplant
- Intra uterine transfusion

138
Q

Tropical infections commonly causing splenomegaly

A

Malaria

Leishmaniasis

Schistosomiasis

Trypanosomiasis

139
Q

Leishmaniasis - laboratory findings

A

Hyergammaglobulinaemia

Normochromic anaemia

Raised ESR

Bone marrow aspirate shows macrophages containing Leishman-Donovan bodies

140
Q

Leishmaniasis - management

A

Pentavalent antimonial compounds or with amphotericin B (AmBisone)

141
Q

Lymphatic filariasis - causative organism

A

Filarial worm - Wuchereria Bancrofti

142
Q

Lymphatic filariasis - clinical features

A

Fever

Pain

Acute inflammation

143
Q

Lymphatic filariasis - management

A

Diethylcarbamazine (unlicensed)

Chemotherapy

144
Q

Trypanosomiasis - transmission

A

The parsites (Trypanosome brucei gambiense and Brucei rhodesiense) transmitted by tsetse fly

145
Q

Trypanosomiasis - clinical features

A

Fever

Lymphadenopathy

Anaemia

Splenomegaly

Progressive parasitaemia
- Drowsiness
- Meningoencephalititis

Complications - haemolytic anaemia, thrombocytopenia and DIC

146
Q

Trypanosomiasis - diagnosis

A

Pentamidine (antimicrobial) and Suramin

Medicine - Year 2 (27 decks)

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