Haematology

RJG Cuthbert

Belfast City Hospital

Erythrocyte Sedimentation Rate

Rouleaux

Max. in mm in 1 hour @ 20oC± 3oC)

Males Females17 - 50 yrs 10mm 12 mm51 - 60 years 12 mm 19 mm 61 - 70 years 14 mm 20 mm> 70 years 30 mm 35 mm

ESR

Indications

• Diagnostic evaluation:– Inflammatory disorders– Neoplasm– Infectious disorders

• Monitor diseaese:– Temporal arteritis– Polymyalgia rheumatica– Inflammatory arthritis

Coagulation Screen

• Platelet count• Prothrombin time• Activated partial thromboplastin time• Thrombin clotting time or fibrinogen

TF TF/VIIa

X IX

IXaVIIIa

Xa

II IIa

Fibrinogen Fibrin

Va

XIIa XII

KallikreinHMW kininogen

The CoagulationCascade

Indications

• History:– Recurrent epistaxis– Recurrent spontaneous bruising– Unexplained menorrhagia– Unexplained prolonged bleeding after

invasive procedures or childbirth– Family history

Indications

• Acute bleeding

• Warfarin – INR only

• Liver & renal disease:– Acute/chronic bleeding– Invasive procedures

• Obstructive jaundice

• Severe sepsis – DIC

• Paracetamol overdose

Not Required

• Routine pre-op, etc– Take a history

• Routine acute medical admission – Take a history – Warfarin

Sample Collection

Correct

Over-filled

Under-filled

D-dimers

Indications

• Suspected DIC

• Assessment of thrombolytic therapy

• Suspected DVT or PE– only used with a clinical risk prediction model

Not indicated

• DVT/PE assessment:– Within 4 weeks of surgery– Trauma cases– Acute/chronic infection– Pregnancy

• Sole test for positive diagnosis of DVT/PE

Heparin-induced Thrombocytopenic Thrombosis

• Patients receiving any heparin preparation including heparin/saline flushes:– New acute thrombotic problems– Thrombocytopenia

Category

Pre-test Probability Scoring______________________________________________________

2 1 0

Plt count >50% fall or

nadir 20-100

30-50% fall or

10-19

<30% fall

nadir <10

Timing 5-10 days or

<1 day if recent heparin exposure

>10 days < 5 days if no recent heparin exposure

Thrombosis New thrombosis; skin necrosis; post heparin acute systemic reaction

Progressive or recurrent thrombosis; erythematous skin lesions; suspected thrombosis

None

Other causes of

thrombosis

No other cause for platelet count fall

Possible other cause

Definite other cause

Action based on score

• High (6-8): Send test and treat without result

• Intermediate (4–5): Wait for test result

• Low (0–3): No need to test

• Contact haematology if puzzled

Thrombophilia Screen

• Inherited:– Anti-thrombin deficiency– Protein C deficiency– Protein S deficiency– APC resistance– Factor V Leiden– Prothrombin G20210A

• Acquired:– Lupus anticoagulant

TF/VIIa

X IX

IXaVIIIa

Xa

II IIa

Fibrinogen Fibrin

Va AT

PC

TFPI

PS

Anticoagulant Proteins

Indications:

• Recurrent DVT/PE < 40 years

• Spontaneous DVT/PE < 40 years

• Recurrent DVT/PE & strong family history

Not indicated

• DVT after– trauma, surgery, immobility, cancer– pregnancy, oral contraceptive pill, HRT

• Single episode of DVT/PE >40 years

• Arterial thrombosis– Lupus anticoagulant – selected cases

Timing of Investigation

• Unreliable results:– Acute thrombosis, pregnancy, OCP, HRT,

anticoagulants

• Early diagnosis does not influence acute management

• Avoid testing during:– Acute thrombotic event– Other acute intercurrent illness– Pregnancy– OCP, HRT, or anticoagulants