47 Haematology

 

Haematology history and exam routines

http://www.oscehome.com/Hematology-OSCEs.html

 

Lymphadenopathy

Head neck and upper limb nodes
Examine systematically.
pre-auricular
post-auricular
occipital
Neck nodes From front of patient examine back and sides of neck. Then sit patient forward and continue palpation from behind
submandibular
submental
tonsillar
anterior and posterior triangles
supraclavicular
Troisiers sign- enlargement of left supraclavicular nodes (virchows node) in Ca stomach.
epitrochlear

youtu.be/sMsGL7l9F5Y

Lymphadenpathy may be localised or generalised and generally reflects infection or malignanacy primary (lymphoma or leukaemia) or secondary.

Refer any adult with a persistent, progressively-growing lymph node of >0.5 cm, even if they are entirely well, probably within 4 weeks. Patients with lymphoma are often systemically well; only a third will be symptomatic at presentation.
Other possible causes of persistent nodes include viral infection (especially Epstein-Barr virus (EBV) and cytomegalovirus (CMV)), bacterial infection (eg TB), toxoplasmosis and other neoplasms. Bone Marrow Failure

 

Haemopoiesis / Reticuloendothelial System

 

Blood composition

http://hacking-medschool/fbc

 

Anaemias

Anaemias

 

Anaemia Classifications

Classify by mean cell volume
Microcytic iron deficiency, haemoglobinopathies (sickle cell disease, thalassaemia).
Normocytic blood loss, chronic disease, bone marrow failure, haematological disease, hypogonadism
Macrocytic vitamin BI2 or folate deficiency, alcoholism, hypothyroidism

Also: hereditary and haemolytic anaemias

 

Anaemia of Chronic Disease

 

Haemolytic Anaemias

youtube.com/watch?v=JWXC8yXe9dE

 

Aplastic Anaemias

Aplastic Anaemia Trust

 

Polycythaemia

Raised red cell mass (>6×10-6 RBC/mm3 or haematocrit >55%) due to increased red cell production.

May be due to primary overproduction in bone marrow (PRV) or secondary to chronic hypoxia (high altitude, haemoglobinopathies, cyanotic CHD, COPD, renal disease, fibroids, hepatoma and cerebellar haemgioblastoma.

Spurious polycythaemia (relatively high red cell mass with low plasma volume) is seen in smoking anxiety and hypertension.

 

Sickle Cell Disease

 

Thalassaemia

Suspect if the mean cell volume (MCV) is low, but the patient is not iron-deficient.

Alpha-thalassaemia
found mainly in South East Asia and West Africa, the prevalence being 20-30% in these countries.
There are four genes coding for alpha-globin per cell, and clinical manifestations depend on how many of these genes are deleted in a particular individual. Deletion of one or two genes does not produce symptoms, although the patient may be slightly anaemic, with a low MCV. Deletion of three genes causes HbH disease, which has a variable presentation; patients are usually anaemic, with haemoglobin concentrations of between 7 and 11 g/dl. Deletion of all four genes is not compatible with Iife and resuIts in Hb Bart’s hydrops fetalis syndrome.

Beta-thalassaemia
trait is common in southern Europe, South East Asia, Africa, the Middle East, South Asia and China.
Heterozygous betathalassaemia does not usually produce symptoms, although patients may be mildly anaemic with a low MCV. Homozygous beta-thalassaemia results in either beta-thalassaemia major (Cooley’s disease), which presents with severe
anaemia and failure to thrive in infancy, or in beta-thalassaemia intermedia, which results in a moderate anaemia after the age of 1-2 years. Patients with the latter usually remain fairly well and only require transfusions during intercurrent illness.

Beta-thalassaemia trait is excluded by Hb electrophoresis, but alpha-thalassaemia trait is not. If diagnosis of alpha-thalassaemia is required, for example in antenatal screening, this is done with DNA studies.

 

Porphyrias

 

Bleeding Disorders

 

Bruising and Purpura

 

Thrombophilias

 

Haemophilia

 

Von Willebrand disease

 

Antiphospholipid Syndrome

Antiphospholipid syndrome is defined by the presence of antiphospholipid antibodies either lupus anticoagulant or anticardiolipin antibodies. If it is an incidental finding and the patient is asymptomatic, treatment is not strictly necessary, although some doctors might consider using 75 mg aspirin daily.

If, however, the patient has a history of miscarriage, deep vein thrombosis, pulmonary embolism or transient ischaemic attack, then referral for anticoagulation is appropriate. After the first event, warfarin may not be considered essential for lifelong use, especially if there was a precipitating factor such as pregnancy or immobility. However, after a second event, initiation of long-term anticoagulation is usual.

The major clinical features of the anti-phospholipid antibody syndrome include:

1 Recurrent thrombotic events including venous thromboses, cerebrovascular thromboses, myocardial infarctions in patients without significant risk factors. Unusual sites of thromboses such as renal vein, hepatic vein, axillary vein as well as renal artery, mesenteric artery and digital artery may be a reason to suspect the presence of this syndrome even in a patient with a single coagulation event. As a general rule, patients tend to have their recurrent thrombi in either the venous or the arterial circulation but not in both sides of the vascular tree.

2. Recurrent spontaneous abortions occurring in the first and second trimester. These abortions are believed to be due to placental insufficiency, probably mediated through micro thrombi in the placenta.

3. Focal central neurological lesions including optic neuritis, transverse myelitis and organic brain syndrome. These features of the anti-phospholipid antibody syndrome do not appear to be mediated by thrombi and may represent direct end organ damage mediated by the anti-phospholipid antibodies or some other autoantibody linked in some fashion to the production of anti-phospholipid antibodies.

4. Chronic thrombocytopenia has been frequently seen in these patients. In most of the patients the platelet counts have been moderately depressed but severe and clinically important thrombocytopenia has been encountered especially in those patients who have lupus.

5. Livedo reticularis is a very common feature of the disease and is probably mediated by thrombi in the deep dermal arterioles. While of no significance clinically, this feature is so characteristic of this syndrome that it should alert the physician to look for other features of the syndrome.

 

Leukaemias

  • ALL Acute Lymphoblastic Leukaemia
  • AML Acute Myeloid Leukaemia
  • CLL Chronic Lymphoid Leukaemia
  • CML Chronic Myeloido Leukaemia

 

Acute Lymphoblastic Leukaemia

 

Acute Myeloid Leukaemia

 

Chronic Lymphoid Leukaemia

 

Chronic Myeloid Leukaemia

 

Myeloproliferative disorders

 

Hodgkins

 

Non-Hodgkins

 

Multiple myeloma

 

Anaphylactoid Purpura

Henoch-Schoenlein Purpura

 

Vasculitis

 

Polyarteritis nodosum

 

ABO blood groups

and rhesus compatibility

Agglutinogens = surface antigens on RBCs
Agglutinins = antibodies in the plasma
Agglutination = clumping together and lysis of donated cells following incompatible transfusion

 

Comments are closed.