Interpreting blood results Flashcards
If a patient has raised Hb but low circulating volume, what is this indicative of?
Relative polycythaemia i.e. concentrated
lower plasma volume caused by burns, dehydration, fluid loss –> apparent Hb rise
You find a raised Hb and then note that circulating volume, WCC and platelets are all high, what does this indicate?
primary polycythaemia - usually polycythaemia vera
Hb and circulating volume high
WCC and platelets low
What does this indicate?
secondary polycythaemia
Hypoxia = EPO release (COPD, local renal hypoxia, sleep apnoea, altitude)
EPO production increased (Cushings, cerebellar haemangioma)
Exogenous intake (often athletes)
What diseases can cause increased EPO production?
hydronephrosis Polycystic kidneys/liver Renal/Hepatic carcinoma Cushings Cerebella haemangioma
What are signs of primary causes of raised platelets?
symptoms
+
hepatosplenomegaly
What can cause a raised platelet count?
Reactive: infection, surgery Iron deficiency anaemia Myeloproliferative disorder Other malignancy Hyposplenism
What can cause a low platelet count (thrombocytopenia)?
Marrow damage: malignancy, virus, alcohol
Increased clearance: DIC, TTP, ITP, HELLP
Splenomegaly eg malaria, liver cirrhosis
Dilutional following red cell transfusion
What can cause neutropenia?
Drugs: clozapine, carbimazole Virus: HIV, EBV Marrow failure: malignancy Reduced B12 or folate Immune diseases: RA, SLE Benign ethnic neutropenia
What can cause neutrophilia?
reactive: infection, inflammation (IBD, RA)
malignancy: myeloproliferative, CML
Hypo/asplenism
Hypoxia
Drugs: lithium, steroids
What can cause lymphadenopathy
Malignancy
Infection
Granulomatous diseases: TB, sarcoid
Collagen vascular diseases: SLE, RA, sjogrens
where is a bone marrow sample often taken from?
Posterior superior iliac crest
What is the difference between a bone marrow aspiration and a trephine?
aspiration is liquid portion of the marrow
trephine take a solid piece
