Haematology Diseases Flashcards
1
Q
What is the epidemiology of DVTs?
A
25-50% of surgical patients
65% of below knee DVTs are asymptomatic and rarely embolise to the lung
Commonly occurs after periods of immobilisation
2
Q
What are the risk factors for DVTs?
A
Increased age Pregnancy Synthetic oestrogen Trauma or surgery Past DVT Cancer Obesity Immobilisation
3
Q
What are the causes of DVT?
A
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
4
Q
What are the clinical features of DVT?
A
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
5
Q
How is DVT diagnosed?
A
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
6
Q
How is DVT treated?
A
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
7
Q
How is DVT prevented?
A
Early mobilisation post op
Compression stockings
Thrombophylaxis
8
Q
What are the complications of DVT?
A
Pulmonary embolism
9
Q
What are the causes of heart failure?
A
IHD (Main cause), cardiomyopathy, valvular heart disease, hypertension, cor pulmonale, alcohol excess, pregnancy, obesity etc.
10
Q
What is the epidemiology of heart failure?
A
25-50% of patients die within 5 years of diagnosis
1-3% of population
10% of elderly
11
Q
What are the risk factors for heart failure?
A
65 and over African descent Men (due to low oestrogen) Obesity Post MI Pregnancy
12
Q
How is heart failure treated?
A
Lifestyle changes= Avoid large meals, lower BMI, smoking cessation, vaccination
- Diuretics
- Aldosterone antagonist
- ACE inhibitors
- Beta blocker
- Digoxin
- Surgical measures
13
Q
How is heart failure diagnosed?
A
- Blood tests first line= High BNP
- Chest X ray= Alveolar oedema, cardiomegaly, effusions
- ECG= Ischaemia, LV hypertrophy, arrhythmia
- Echocardiography
14
Q
What is the clinical presentation of heart failure ?
A
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
15
Q
What are the classes of heart failure?
A
Systolic or diastolic
Acute or chronic
16
Q
What is systolic heart failure and what causes it?
A
Ventricle cant contract normally, caused by IHD, MI etc
17
Q
What is diastolic heart failure and what causes it?
A
Ventricle can’t relax fully to properly fill. Caused by hypertrophy (due to hypertension) or aortic stenosis
18
Q
Briefly explain the pathophysiology of heart failure
A
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
19
Q
What is the epidemiology or pernicious anaemia?
A
- Common in elderly
- More common in females
- An association with other autoimmune diseases
20
Q
What are the risk factors for pernicious anaemia?
A
- Elderly
- Female
- Fair-haired, blue eyes
- Blood group A
- Thyroid and Addison’s disease
21
Q
Briefly explain the pathophysiology of pernicious anaemia
A
- 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
22
Q
What are the general clinical features of anaemia?
A
- Fatigue
- Headache
- Dyspnoea
- Anorexia
- Palpitations
- Pallor
- Tachycardia
- Heart failure/ Angina
- Heart murmur
23
Q
What are the specific clinical features of pernicious anaemia?
A
- 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.
24
Q
How is pernicious anaemia diagnosed?
A
- 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)
25
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
26
What is the epidemiology of iron deficiency anaemia?
Most common cause of anaemia worldwide. Seen in 14% of menstruating women
27
What are the causes of iron deficiency anaemia?
- Blood loss= Menorrhagia, GI bleeding (Hookworm)
- Poor diet
- Increased demands= Growth and pregnancy
- Malabsorption
28
What are the risk factors for iron deficiency anaemia?
- Undeveloped countries
- High veg diet
- Premature infants
- Introduction of mixed feeding delayed
29
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
30
What is the average daily intake of iron?
15-20 mg
31
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
32
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
33
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
34
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
35
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
36
What are the risk factors of anaemia of chronic disease?
Have a chronic disease
37
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
38
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)
39
How is anaemia of chronic disease treated?
- Treat underlying cause
| - Erythropoietin is effective (SE: Flu like symptoms, mild rise in platelet count, hypertension)
40
What is MCV?
Mean corpuscular volume
41
What is the MCV in normocytic anaemia?
Normal
42
What is the MCV in microcytic anaemia?
Low
43
What is the MCV in macrocytic anaemia?
High
44
What are the main causes of microcytic anaemia?
- Iron deficiency anaemia= most common cause
- Anaemia of chronic disease
- Thalassaemia
- Congenital sideroblastic anaemia
- Lead poisoning
45
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
46
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)
47
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
48
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
49
How is normocytic anaemia diagnosed?
- Normal B12 and folate
- Raised reticulocytes
- Hb down
- Blood count and film: RBCs are normocytic
50
How is normocytic anaemia treated?
- Treat underlying cause
- Improve diet with plenty of vitamins
- Erythropoietin injections
51
What are the four types of leukaemia?
- Acute myeloid leukaemia
- Acute lymphoblastic leukaemia
- Chronic myeloid leukaemia
- Chronic lymphocytic leukaemia
52
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
53
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
54
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
55
What are the complications of acute myeloid leukaemia?
- Infection= Common organisms present oddly with few antibodies being made
56
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
57
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
58
What are the complications of chronic lymphocytic leukaemia?
- Autoimmune haemolysis
- Increased infection risk - hypogammaglobulinaemia
- Marrow failure
- Progression
59
How is chronic lymphocytic leukaemia treated?
- Blood transfusion
- Human IV immunoglobulins
- Chemo or radiotherapy
- Try stem cell transplant
60
What is the prognosis of chronic lymphocytic leukaemia?
- 1/3 will never progress
- 1/3 progress slowly
- 1/3 will progress actively
61
What is the epidemiology of chronic myeloid leukaemia?
- Most exclusively a disease of adults
- Occurs between 40-60 yrs
- Slight male predominancy
- More than 80% have Philadelphia chromosome
62
What is the epidemiology of chronic lymphocytic leukaemia?
- Most common leukaemia
| - Occurs predominantly later in life
63
What are the clinical features of chronic myeloid leukaemia?
- Symptomatic anaemia e.g. breathlessness
- Abdominal discomfort= splenomegaly
- Weight loss, pallor, fatigue
- Fever and sweats
- Features of gout due to purine breakdown
- Bleeding due to platelet dysfunction
64
How is chronic myeloid leukaemia diagnosed?
- Blood count= v high wcc, low Hb (normochromic and normocytic)
- Bone marrow aspirate= hypercellular
65
How is chronic myeloid leukaemia treated?
- Oral imatinib
| - Stem cell transplant
66
What is the epidemiology of acute lymphoblastic leukaemia?
- Most common between 2-4 (commonest cancer in childhood)
67
What is chronic lymphocytic leukaemia?
- Accumulation of mature B cells that have escaped apoptosis and undergone cell-cycle arrest
68
What is chronic myeloid leukaemia?
- Uncontrolled clonal proliferation of myeloid cells
69
What is acute myeloid leukaemia?
- Neoplastic proliferation of blast cells derived from marrow myeloid (giving rise to basophils, neutrophils, eosinophils etc)
70
What is acute lymphoblastic leukaemia?
- Malignancy of immature lymphoid cells (give rise to T and B cells). Arrests the maturation and promotes uncontrolled proliferation of immature blast cells. Majority of cases derive from B cell precursors
71
What are the clinical features of acute lymphoblastic leukaemia?
- Anaemia= low Hb. Resulting in breathlessness, fatigue, angina, claudication
- Infections
- Bleeding= Bruising, bleeding, bone pain, hepatosplenomegaly, lymphadenopathy, Headache, nerve palsies
72
How is acute lymphoblastic leukaemia diagnosed?
- FBC and blood film= WCC is usually high, blast cells on film and in bone marrow
- CXR and CT to look for mediastinal and abdominal lymphadenopathy
- Lumbar puncture to look for CNS involvement
73
How is acute lymphoblastic leukaemia treated?
- Blood and platelet transfusion
- Neutropenia- treat prophylactically with antibacterials, antifungals and antivirals
- Allopurinol to prevent tumour lysis syndrome
- IV fluids via Hickman line
- Chemotherapy
- Marrow transplantation
74
What are the risk factors for Hodgkin's lymphoma?
- Affected siblings
- EBV
- SLE
- Obesity
- Post transplantation
75
What is the epidemiology of Hodgkin's lymphoma?
- Male predominance
- Majority occurs in teenagers and elderly
- EBV
76
What are the two types of Hodgkin's lymphoma?
- Classical Hodgkin's lymphoma
| - Nodular lymphocyte predominant Hodgkin's lymphoma
77
What is the emergency presentation of Hodgkin's lymphoma?
- Infection
- Superior vena cava obstruction, with increased jugular venous pressure
- Sensations of fullness in the head
- Dyspnoea
- Blackouts
- Facial oedema
78
What are the clinical features of Hodgkin's lymphoma?
- Often only a painless "rubbery" cervical lymphadenopathy
- A smaller proportion of patients (often young women) present with disease localised to the mediastinum with a cough
- Others present with generalised disease including hepatosplenomegaly, weight loss, fever and night sweats
79
How is Hodgkin's lymphoma diagnosed?
- CT/MRI of chest, abdomen and pelvis for staging
- Lymph node excision or bone marrow biopsy- will see "popcorn cells"
- Bloods- High ESR/ Low Hb= Worse prognosis, High serum lactate dehydrogenase
- Immunophenotyping
- Cytogenetics
- PET scan
80
How is Hodgkin's lymphoma treated?
- Combination chemotherapy
- If less advanced, short course of chemotherapy, followed by radiotherapy
- If advanced, longer course of chemotherapy
81
What are the stages of Hodgkin's lymphoma?
```
1= Single lymph node
2= 2+ Lymph nodes on same side of diaphragm
3= Nodes on both sides of diaphragm
4= Spread beyond nodes
Also A (no systemic symptoms) or B (Symptomatic)
```
82
What is the epidemiology of Non-Hodgkin's lymphoma?
- Around 80% is of B cell origin
| - Around 20% is of T cell origin
83
What are the risk factors of Non-Hodgkin's lymphoma?
- Family history is linked with a minor increase in risk
84
What are the clinical features of Non-Hodgkin's lymphoma?
- Nodal disease (75%) e.g. superficial lymphadenopathy
- Extranodal disease (25%) = skin, oropharynx, gut, bone, small bowel etc
- Systemic B symptoms= Fever, weight loss, night sweats
- Pancytopenia- anaemia, infection and bleeding
85
What are the classifications of Non-Hodgkin's lymphoma?
- Low/indolent grade= slow growing, usually advanced at presentation, incurable. Median survival of 9-11 yrs
- High grade= Usually has nodal presentation, 1/3 of cases have extranodal involvement
86
How is Non-Hodgkin's lymphoma diagnosed?
- Raised lactose dehydrogenase reflects worse prognosis
- Lymph node excision/ bone marrow biopsy
- Marrow and node biopsy for classification
- CT/MRI of chest, abdomen and pelvis for staging
- Immunophenotyping
- Cytogenetics
87
How is Non-Hodgkin's lymphoma treated?
- R CHOP= Rituximab, cyclophosphamide, hydroxy-duanorubioin, Oncovin (brand name for vincristine), prednisolone
- In low grade, radiotherapy may be curative
88
Briefly explain the pathophysiology of Burkitts lymphoma?
- The accumulation of malignant plasma cells in the bone marrow
- In myeloma, the malignant plasma cells produce an excess of one type of immunoglobulin (usually IgG) and other immunoglobulins are low
89
What is the epidemiology of Burkitts lymphoma?
- Disease of old age
- Peak age is 70 yrs
- More common in Afro-Carribbean populations
90
What are the clinical features of Burkitts lymphoma?
- Renal failure (as raised immunoglobulins are proteins which precipitate and deposit in organs especially kidneys)
- Anaemia= neutropenia or thrombocytopenia resulting in infection, bleeding, fatigue and pallor
- Bone lytic lesions= bone pain and fractures
91
How is Burkitts lymphoma diagnosed?
- Blood: normocytic normochromic anaemia, raised ESR, rouleaux formation on blood films
- U&Es: Raised calcium and alk phosphatase
- Bence-jones protein in urine
- X ray shows lytic lesions
- Monoclonal protein band in serum or urine
- Raised plasma cells on bone marrow biopsy
92
How is Burkitts lymphoma treated?
- Bone pain supported with analgesia and bisphosphonates for fracture
- Anaemia treated with RBC transfusion and EPO
- Rehydrate
- Renal dialysis
- Treat infections
- Chemotherapy
- Stem cell transplant
93
What are the clinical features of myeloma?
OLD CRAB
- Old age
- Calcium elevated
- Renal failure
- Anaemia
- Bone lytic lesions
94
How is myeloma diagnosed?
- Blood: normocytic normochromic anaemia, raised ESR, rouleaux formation on blood films
- U&Es: Raised calcium and alk phosphatase
- Bence-jones protein in urine
- X ray shows lytic lesions
- Monoclonal protein band in serum or urine
- Raised plasma cells on bone marrow biopsy
95
How is myeloma treated?
- Bone pain supported with analgesia and bisphosphonates for fracture
- Anaemia treated with RBC transfusion and EPO
- Rehydrate
- Renal dialysis
- Treat infections
- Chemotherapy = VAD
- Stem cell transplant
96
What is polycythaemia?
An increase in haemoglobin, haemocrit and red cell count by concentration.
97
What are the types of polycythaemia?
- Absolute (increase in RBC mass) = Polycythemia vera, hypoxia etc
- Relative (Decreased plasma vol and normal RBC mass) = dehydration, apparent polycythaemia
98
What is over anticoagulation?
- Excess use of anticoagulation therapy
99
What are the clinical features of over anticoagulation?
- Bleeding
100
What are the risk factors for over anticoagulation?
- Iatrogenic (inappropriate prescription of warfarin/ heparin)
101
What are the treatments for over anticoagulation?
- Warfarin= Phytomenadione
| - Heparin= Protamine sulfate
102
Briefly explain the pathophysiology of polycythaemia vera
- A clonal stem cell disorder resulting in a malignant proliferation of a clone derived from one pluripotent marrow stem cell
- The erythroid progenitor offspring are unusual in not needing EPO to avoid apoptosis
- This results in the excess proliferation of RBCs, WBCs, and platelets which causes raised haemocrit
103
What are the possible complications of polycythaemia vera?
Thrombosis and haemorrhage
104
What are the clinical features of polycythaemia vera?
- May be asymptomatic
- May present with vague symptoms due to hyperviscosity: headaches, tiredness, dizziness, tinnitus, visual disturbances
- Severe itching
- Erythromelalgia- burning sensation in fingers and toes
- Gout
- Hypertension, angina, intermittent claudication
- Plethoric complexion
- Hepatosplenomegaly
105
How is polycythaemia vera diagnosed?
- Blood count= raised WCC and platelets, raised Hb
- Presence of JAK2 mutation on genetic screen
- Bone marrow biopsy showing prominent erythrothyroid, granulocytic and megakarocytic proliferation
- Serum EPO low
106
How is polycythaemia vera treated?
- No cure
- Venesection= aims to lower PCV and platelet count
- Chemotherapy= hydroxycarbamide and low dose bulsulfan for those who dont tolerate venesection
- Low dose aspirin
- Radioactive phosphorus
- Allopurinol to reduce gout
107
What causes immune thrombocytopenia purpura?
Immune destruction of platelets
108
How is immune thrombocytopenia purpura diagnosed?
- Bone marrow examinaiton= shows thrombocytopenia with increased/normal megakaryocytes
- Platelet autoantibodies in 60-70%
109
How is immune thrombocytopenia purpura treated?
- First line= Corticosteroids e.g. prednisolone, and IV immunoglobulins
- Second line= Splenectomy, or if this fails, immunosuppression
110
What are the clinical features of immune thrombocytopenia purpura?
- Easy bruising
- Epistaxis
- Menorrhagia
- Purpura
- Gum bleeding
111
What is the aetiology of thrombotic thrombocytopenia purpura?
- Idiopathic
- Autoimmune e.g. SLE
- Cancer
- Pregnancy
- Drug associated e.g. quinine
112
What are the clinical features of thrombotic thrombocytopenia purpura?
- Floroid purpura
- Fever
- Fluctuating cerebral dysfunction
- Haemolytic anaemia with red cell fragmentation, often accompanied by AKI
113
How is thrombotic thrombocytopenia purpura diagnosed?
- Lactate dehydrogenase is raised due to haemolysis
114
How is thrombotic thrombocytopenia purpura treated?
- Plasma exchange to remove antibody to ADAMTS-13 as well as provide a source of ADAMTS-13
- IV methylprednisolone
- IV Rituximab
115
What are the clinical features of sickle cell disease?
- Acute pain in hands and feet. Worse in cold.
- Anaemia
- Pulmonary hypertension
- Growth delay
- Recurrent infection
- Hepatomegaly and liver dysfunction
- Retinopathy, vitreous haemorrhage
116
Briefly explain the pathophysiology of sickle cell disease?
Changes in the alpha-alpha sequence of a Hb subunit causes a faulty Hb complex. This distorts the shape of rbc into sickles when deoxygenated, which are easily destroyed and occlude vessels easily. This process worsens with repeated oxygenation/deoxygenation.
117
What is the epidemiology of sickle cell disease?
- More common in African populations
118
What are the risk factors for sickle cell disease?
- African
| - Family history
119
How is sickle cell disease diagnosed?
- Identified in neonatal screening
- Blood film= sickled cells
- Sickle solubility test will be positive
- Hb in range of 60-80g/L, raised reticulocyte count
120
How is sickle cell disease treated?
- Folic acid
- Pain relief
- BMT in severe disease
- Oral hydroxycarbamide
121
What are the causes of DIC?
- Massive activation of the coagulation cascade
- Sepsis
- Major trauma
- Advanced cancer
- Obstetric complications
122
What is the epidemiology of DIC?
Never occurs in isolation
123
What are the clinical features of DIC?
- Patient is acutely ill and shocked
- Bleeding may occur from mouth, nose and venepuncture sites
- Widespread ecchymoses
- Confusion
- Bruising
124
How is DIC diagnosed?
- Severe thrombocytopenia
- Decreased fibrinogen
- Increased FDPs e.g. D dimer
- Blood film= Fragmented RBC
- Prolonged PTT, Activated partial thromboplasmin time and Thrombin time
125
How is DIC treated?
- Treat underlying condition
- Replace platelets if very low via transfusion
- Fresh frozen plasma to replace coagulation factors
- Cytoprecipitate to replace fibrinogen and coagulation factors
- RBC transfusion in patients who are bleeding
126
What are the clinical features of thalassemia?
- Variable
- Alpha presents in utero, whilst beta in infancy
- Can be asymptomatic if heterozygotes or severe anaemia in homozygotes, with failure to thrive and bone deformities
127
Briefly explain the pathophysiology of thalassemia?
Defective versions of either alpha or beta subunits of Hb= inbalance of subunits available= Precipitation of globin chains within RBC (or precursor) = Cell damage, death of precursor and haemolysis
128
What is the epidemiology of thalassemia?
- 1% Carriers of beta
| - 5% Carriers of alpha
129
How is thalassemia diagnosed?
- Either genetic testing or haemoglobin electrophoresis
130
How is thalassemia treated?
- Homozygotes= blood transfusions to avoid complications. Iron chelating agents for overload (deferoxamine). Ascorbic acid increases iron excretions in urine.
- More severe= BMT
131
What are possible complications of thalassemia?
- Iron overload, endocrine dysfunction
132
What are the clinical features of glucose-6-phosphate dehydrogenase deficiency?
- Most are asymptomatic
- Neonatal jaundice
- Haemolytic anaemia
- Acute haemolysis
133
What is the aetiology of glucose-6-phosphate dehydrogenase deficiency?
- X linked recessive
| - Linked to Fava beans
134
What is the epidemiology of glucose-6-phosphate dehydrogenase deficiency?
- Most common metabolic RBC disorder
- Affects predominantly in Africa, around the Mediterranean and in the Middle East
- Heterogenous X linked = More common in males
135
How is glucose-6-phosphate dehydrogenase deficiency diagnosed?
- Direct measurements of enzymes in RBC
- Blood film during attack= Irregularly contracted cells, bite cells, reticulocytosis
- G6PD enzyme levels low
136
How is glucose-6-phosphate dehydrogenase deficiency treated?
- Avoid fava beans
| - Transfusion if necessary
137
What are the clinical features of malaria?
- Most with falciparum present in first month
- No specific symptoms
- Fever, chills, rigor, cough, myalgia, hepatosplenomegaly
- Severe: Impaired consciousness, shortness of breath, bleeding, fits, hypovolaemia
138
What are the risk factors for malaria?
- Poor
- Young
- Pregnant
- Elderly
- Recently travelled abroad
139
How is malaria diagnosed?
- Blood smear with giemsa stain
140
How is malaria treated?
- Non falciparum: chloroquine
- Falciparum: Quinine sulfate, atovaquone-proguaril and artemether with lumefantrine
- Severe: IV quinine dihydrochloride
141
Briefly explain the pathophysiology of haemophilia A
- Factor VIII Deficiency
| - X linked
142
Which is more common; haemophilia A or haemophilia B?
A
143
How is haemophilia diagnosed?
- FBC= Low heamocrit, low Hb
- Normal prothrombin time
- Prolonged partial thromboplastin time
- Low factor VIII/ IX
144
What are the clinical features of Haemophilia A?
- Mild disease bleed after trauma
- Bleeding following venepuncture
- Neonatal bleeding
- GI bleeds
- Haematuria
145
How is haemophilia A treated?
- Prophylactic factor VIII
- Desmopressin for factor VIII
- Fresh frozen plasma containing factor VIII for acute bleeds
146
How is haemophilia B treated?
- Recombinant factor IX
- Vaccinated against Hep A and B
- Medical emergency bracelet
147
Briefly explain the pathophysiology of haemophilia B?
- Factor IX deficiency
| - Male predominance (X linked)
148
What are the clinical features of haemophilia B?
- Bruising
- Epistaxis
- Pallor
- Haemoptysis
- Heavy bleeding following trauma
- Joint pain and stiffness
- Headache, irritability, vomitting
149
How is arterial thrombosis treated?
Anti-platelets e.g. aspirin, clopidogerel
150
How is venous thrombosis treated?
Anti-Coagulants e.g. warfarin, heparin, NOACs
151
What are the clinical features of arterial thrombosis?
- Diminished or absent pulse
- Pain= intermittent claudication
- Cold
- Rubor
