Haematology Diseases Flashcards
What is the epidemiology of DVTs?
25-50% of surgical patients
65% of below knee DVTs are asymptomatic and rarely embolise to the lung
Commonly occurs after periods of immobilisation
What are the risk factors for DVTs?
Increased age Pregnancy Synthetic oestrogen Trauma or surgery Past DVT Cancer Obesity Immobilisation
What are the causes of DVT?
Surgery, immobility, leg fractures, oral contraceptive, malignancy, long haul flights
Genetic: Factor V leiden (5%)m and PT2021OA (3%) = both common in caucasian populations
Acquired: Anti-phospholipid syndrome, lupus anticoagulant, hyperhomocysteinaemia
What are the clinical features of DVT?
May be asymptomatic
Pulse is present
Pain in calf- often swelling, redness and engorged superficial veins
With complete occlusion, can result in cyanotic discouration and severe oedema
How is DVT diagnosed?
Plasma D dimer= Type of fibronigen degradation product that is released when a clot begins to dissolve. Plasma D dimer is not diagnostic, but a normal result can exclude DVT
Compression ultrasound: if popliteal vein can be squashed shut= No DVT, if not= DVT
Venography
Doppler ultrasound
How is DVT treated?
Low molecular weight heparin (e.g. sc enoxaparin) for a minimum of 5 days
Oral warfarin with a target INR of 2.5 by 6 months after
Direct acting oral anticoagulants
Compression stockings
IVC filters
How is DVT prevented?
Early mobilisation post op
Compression stockings
Thrombophylaxis
What are the complications of DVT?
Pulmonary embolism
What are the causes of heart failure?
IHD (Main cause), cardiomyopathy, valvular heart disease, hypertension, cor pulmonale, alcohol excess, pregnancy, obesity etc.
What is the epidemiology of heart failure?
25-50% of patients die within 5 years of diagnosis
1-3% of population
10% of elderly
What are the risk factors for heart failure?
65 and over African descent Men (due to low oestrogen) Obesity Post MI Pregnancy
How is heart failure treated?
Lifestyle changes= Avoid large meals, lower BMI, smoking cessation, vaccination
- Diuretics
- Aldosterone antagonist
- ACE inhibitors
- Beta blocker
- Digoxin
- Surgical measures
How is heart failure diagnosed?
- Blood tests first line= High BNP
- Chest X ray= Alveolar oedema, cardiomegaly, effusions
- ECG= Ischaemia, LV hypertrophy, arrhythmia
- Echocardiography
What is the clinical presentation of heart failure ?
3 cardinal symptoms= Shortness of breath, fatigue, ankle swelling
Dysponea, cold peripheries, raised JVP, Murmurs, cyanosis, hypotension, tachycardia, 3rd and 4th heart sounds, bi-basal crackles, ascites
What are the classes of heart failure?
Systolic or diastolic
Acute or chronic
What is systolic heart failure and what causes it?
Ventricle cant contract normally, caused by IHD, MI etc
What is diastolic heart failure and what causes it?
Ventricle can’t relax fully to properly fill. Caused by hypertrophy (due to hypertension) or aortic stenosis
Briefly explain the pathophysiology of heart failure
When the heart begins to fail, there are compensatory changes to maintain cardiac output and peripheral perfusion. However this is overwhelmed, and leads to decompression-
- Venous return (preload)= Heart tries to increase force of contraction to make up for low ejection fraction, but this fails
- Outflow resistance (afterload)= Increased resistance leads to a lower cardiac output and dilated ventricle
- Sympathetics= Baroreceptors become used to new normal
- RAAS= Not activated in failure, so less blood supply to overworked myocytes leading to cell death
What is the epidemiology or pernicious anaemia?
- Common in elderly
- More common in females
- An association with other autoimmune diseases
What are the risk factors for pernicious anaemia?
- Elderly
- Female
- Fair-haired, blue eyes
- Blood group A
- Thyroid and Addison’s disease
Briefly explain the pathophysiology of pernicious anaemia
- There are many causes of B12 deficiency including dietary, malabsorbtion and pernicious anaemia
- An autoimmune disorder in which parietal cells are attacked resulting in atrophic gastritis and the loss of intrinsic factor
- Therefore B12 can’t be reabsorbed
- B12 is essential for thymidine and DNA synthesis
- Delayed nuclear maturation resulting in large RBCs and lower RBC production
What are the general clinical features of anaemia?
- Fatigue
- Headache
- Dyspnoea
- Anorexia
- Palpitations
- Pallor
- Tachycardia
- Heart failure/ Angina
- Heart murmur
What are the specific clinical features of pernicious anaemia?
- Generalised anaemia symptoms
- Lemon yellow skin due to pallor and mild jaundice (excess haemoglobin breakdown)
- Glossitis and stomatitis/ cheilosis
- Neurological features if v low B12= Symmetrical paresthesia in fingers and toes, weakness and ataxia, dementia etc.
How is pernicious anaemia diagnosed?
- Blood count and film= RBCs are macrocytic, oval macrocytes, hypersegmented neutrophil polymorphs with 6 nuclei
- Serum bilirubin is raised due to ineffective erythropoiesis
- Low serum B12
- Low Hb
- Low reticulocytes
- Intrinsic factor antibodies (insensitive)
How is pernicious anaemia treated?
- If other cause of B12 deficiency, treat cause
- Injections required if low B12 is due to malabsorption
- If dietary then give oral B12
- Replenish B12 stores by IM hydroxocobalamin
What is the epidemiology of iron deficiency anaemia?
Most common cause of anaemia worldwide. Seen in 14% of menstruating women
What are the causes of iron deficiency anaemia?
- Blood loss= Menorrhagia, GI bleeding (Hookworm)
- Poor diet
- Increased demands= Growth and pregnancy
- Malabsorption
What are the risk factors for iron deficiency anaemia?
- Undeveloped countries
- High veg diet
- Premature infants
- Introduction of mixed feeding delayed
Briefly explain the pathophysiology of iron deficiency anaemia?
- Iron ions are required for haem synthesis
- This leads to low haemoglobin
- Therefore lower RBC formation
- Microcytic anaemia
What is the average daily intake of iron?
15-20 mg
What are the clinical features of iron deficiency anaemia?
- General anaemia symptoms
- Brittle nails and hair
- Spoon shaped nails Koilonychia
- Atrophy of papillae of tounge= atrophic glossitis
- Ulceration of corner of mouth= angular stomatitis/ cheilosis
How is iron deficiency anaemia diagnosed?
- Blood count and film= RBC are microlytic and hypochromic, poikilocytosis (variation and RBC size), and anisocytosis (Variation in size)
- Low serum ferritin (But it raises in inflammation so may not be low), and low serum iron
- Low reticulocytes
- High serum transferrin receptors
- Further investigations into possible blood loss
How is iron deficiency anaemia treated?
- Find and treat cause
- Oral iron e.g. ferrous sulphate (GI Side effects), or if CI, then ferrous gluconate
- Parenteral iron e.g. IV iron in extreme cases
What is the epidemiology of anaemia of chronic disease?
- 2nd most common anaemia
- Commonest anaemia in hospital patients
- Occurs in individuals with chronic infections e.g. TB, Crohn’s, RA, SLE, Malignancy
What is the clinical presentation of anaemia of chronic disease?
- Fatigue, headache and faintness
- Dyspnoea and breathlessness
- Anorexia
- Intermittent claudication
- Palpitations
- Angina if pre-existing coronary disease
What are the risk factors of anaemia of chronic disease?
Have a chronic disease
What is the pathophysiology of anaemia of chronic disease?
There is a decreased release of iron from the bone marrow to developing erythroblasts (early RBC before reticulocytes). An inadequate erythropoietin response to anaemia. Decreased RBC survival
How is anaemia of chronic disease diagnosed?
- Serum iron and total iron-binding capicity (TIBC) low
- Serum ferritin is normal or raised due to inflammation
- Serum soluble transferrin receptor level is normal
- Blood count and film: RBCs are normocytic or microcytic and hypochromic (pale)
How is anaemia of chronic disease treated?
- Treat underlying cause
- Erythropoietin is effective (SE: Flu like symptoms, mild rise in platelet count, hypertension)
What is MCV?
Mean corpuscular volume
What is the MCV in normocytic anaemia?
Normal
What is the MCV in microcytic anaemia?
Low
What is the MCV in macrocytic anaemia?
High
What are the main causes of microcytic anaemia?
- Iron deficiency anaemia= most common cause
- Anaemia of chronic disease
- Thalassaemia
- Congenital sideroblastic anaemia
- Lead poisoning
What are the main causes of macrocytic anaemia?
- Megaloblastic= Vit B12 deficiency (cobalamin), folate deficiency
- Non megaloblastic= Alcohol, liver disease, hypothyroidism, haemolysis, bone marrow failure, bone marrow infiltration, myeloma
What are the 2 types of macrocytic anaemia?
- Megaloblastic= Presence of erythroblasts with delayed nuclear maturation due to delayed DNA synthesis (These are megaloblasts, large and have no nuclei)
- Non-megaloblastic= Erythroblasts are normal (normoblastic)
What are the main causes of normocytic anaemia?
- Acute blood loss
- Anaemia of chronic disease
- Renal failure
- Pregnancy
- Endocrine disorders such as hypopituitarism, hypothyroidism and hypoadrenalism
What is the clinical presentation of normocytic anaemia?
- Fatigue, headache and faintness
- Dyspnoea and breathlessness
- Angina if pre-existing coronary disease
- Anorexia
- Intermittent claudication
- Palpitations
How is normocytic anaemia diagnosed?
- Normal B12 and folate
- Raised reticulocytes
- Hb down
- Blood count and film: RBCs are normocytic
How is normocytic anaemia treated?
- Treat underlying cause
- Improve diet with plenty of vitamins
- Erythropoietin injections
What are the four types of leukaemia?
- Acute myeloid leukaemia
- Acute lymphoblastic leukaemia
- Chronic myeloid leukaemia
- Chronic lymphocytic leukaemia
What are the clinical features of acute myeloid leukaemia?
- Anaemia= Low Hb so breathlessness, fatigue, angina, and claudication. There is pallor and cardiac flow murmur
- Infection due to low WCC- fever, mouth ulcers
- Bleeding due to low platelets- Bleeding, bruising, hepatomegaly, splenomegaly, gum hypertrophy, DIC
How is acute myeloid leukaemia treated?
- Blood and platelet transfusion
- Neutropenia may lead to deadly infections- treat with prophylactic antivirals, antifungals and antibacterials
- Allopurinol (prevents tumour lysis syndrome)
- IV fluids via Hickman line
- Chemotherapy
- Marrow transplant
How is acute myeloid leukaemia diagnosed?
- WCC is often raised, but can be normal or even low
- Bone marrow biopsy
- Differentiation from ALL is based on microscopy, immunophenotyping and molecular methods
What are the complications of acute myeloid leukaemia?
- Infection= Common organisms present oddly with few antibodies being made
What are the clinical features of chronic lymphocytic leukaemia?
- Often no symptoms= presenting as a surprise on a routine FBC
- May be anaemic (due to haemolysis or marrow infiltration) or infection prone
- If severe; weight loss, sweats and anorexia
- Enlarged, rubbery, non-tender nodes
- Hepatosplenomegaly
How is chronic lymphocytic leukaemia diagnosed?
- Blood count= normal or low Hb
- Raised WCC with very high lymphocytes
- Smudge cells may be seen in vitro
What are the complications of chronic lymphocytic leukaemia?
- Autoimmune haemolysis
- Increased infection risk - hypogammaglobulinaemia
- Marrow failure
- Progression
How is chronic lymphocytic leukaemia treated?
- Blood transfusion
- Human IV immunoglobulins
- Chemo or radiotherapy
- Try stem cell transplant
What is the prognosis of chronic lymphocytic leukaemia?
- 1/3 will never progress
- 1/3 progress slowly
- 1/3 will progress actively