Home | | Medicine Study Notes | Polycythaemia Vera - Myeloproliferative Disorders (MPD)

Chapter: Medicine Study Notes : Haematology and Immunology

Polycythaemia Vera - Myeloproliferative Disorders (MPD)

Investigation: total red cell volume by 51Cr. Also erythropoietin assay

Polycythaemia Vera

 

·  = Erythrocytosis


 

·        Investigation: total red cell volume by 51Cr.  Also erythropoietin assay

·        Classification (given Raised PCV):

 

o  ­RCM (Red cell mass) = Absolute

o  Normal RCM = apparent

 

Primary Proliferative Polycythaemia

 

·        Clonal stem cell disorder

·        Predominant age 55 – 60 years

·        Diagnosis:

o  RCM > 36 ml/kg (i.e. absolute polycythaemia)

o  No secondary cause: e.g. O2 saturation > 92% (e.g. CORD)

·        Effects: 

o  Vascular complications: TIA, cerebral thrombosis, microvascular (e.g. toes), headaches, DVTs (but usually arterial problems due to ­viscosity e.g. stroke)

o  Haemorrhage

o  Pruritis

o  Gout

o  Splenomegaly (also liver)

·        Lab findings: 

o  Hb & PCV­

o  ­WBC in 2/3

o  ­Serum B12

o  Low erythropoietin

o  Platelets 400 – 800 in 50% 

o  Hypercellular marrow: little fat, ­in megakaryocytes

o  „Hot‟ looking bone scan: lots of activity

o  Tear drop red cells

·        Treatment:

o  Venesection: take off a unit of blood every 3 or 4 months (if old do it slow) 

o  If ­platelets as well (Þ ­clotting risk) then radioactive P32 (risk of leukaemia 10 years on), Busulphan & allopurinol (® ¯gout). Also hydroxyurea 

·        Course:

o  20% progress to myelofibrosis

o  AML transition

o  ?Splenectomy if massive

o  Median survival = 8 – 15 years

 

Secondary Causes of Polycythaemia

 

·        Hypoxia: normal erythropoietin.  High altitude, lung disease, cyanotic CHD, smoking 

·        Inappropriate erythropoietin: renal tumours, renal ischaemia (ascultate for renal bruits), fibroids, hepatoma

·        Miscellaneous: e.g. drugs like androgens for breast cancer

 

Apparent Polycythaemia

 

·        ­Packed cell volume (=PCV = Haematocrit) but normal RCM (ie RBCs a greater proportion of a unit of blood, but normal volume of RBCs in the body): 

o  Diuretics

o  Alcohol

o  Hypertension

o  Early primary polycythaemia

·        High altitude: initially ¯plasma volume then absolute polycythaemia (and O2 curve shifts left)


Study Material, Lecturing Notes, Assignment, Reference, Wiki description explanation, brief detail
Medicine Study Notes : Haematology and Immunology : Polycythaemia Vera - Myeloproliferative Disorders (MPD) |


Privacy Policy, Terms and Conditions, DMCA Policy and Compliant

Copyright © 2018-2024 BrainKart.com; All Rights Reserved. Developed by Therithal info, Chennai.