Clinical Haemotology

Question 1

Pathophysiology of polycythaemia

Answer 1

Polycythaemia is an increase in haematocrit, red cell count and haemoglobin concentration

It may be relative, primary (polycythaemia rubra vera) or secondary

Relative:
dehydration
stress - Gaisbock syndrome

Primary:
polycythaemia rubra vera
Secondary:
COPD
altitude
obstructive sleep apnoea
excessive erythropoietin: cerebellar haemangioma, hypernephroma, hepatoma, uterine fibroids

Question 2

Investigations for polycythaemia

Question 3

Management of plycythaemia

Question 4

Pathophysiology, risk factors and clinical features of DVT

Answer 4

Deep vein thrombosis refers to the intra-luminal occlusion of any vein within the deep system of a limb (either arm or leg) or the pelvis.

Risk factors:

Age >60
Active cancer
Dehydration
Recent orthopaedic or pelvic surgery
Long-distance travel
Obesity
Previous history of VTE
Family history of VTE
Thrombophilias
Combined oral contraceptives and hormone replacement therapy
Pregnancy

Clinical Features
Unilateral warm, swollen calf or thigh
Pain on palpation of deep veins
Distention of superficial veins
Pitting oedema

Question 5

What is the criteria used to score DVT?

Answer 5

The Well score, maximum score is 9 and the minimum is -2.

Question 6

What is the investigation for DVT?

Answer 6

D-dimer - very sensitive but not specific therefore can only exclude venous thromboembolism

Doppler ultrasound with results within 4 hours, if not available within start interim anticoagulation therapy

Question 7

Management of DVT?

Answer 7

interim therapeutic anticoagulation:
1st line - Offer apixaban or rivaroxaban first line

then

low molecular weight heparin (LMWH) for at least 5 days followed by dabigatran or edoxaban

or

LMWH concurrently with a vitamin K antagonist for at least 5 days