Laboratory Haematology &

Transfusion Medicine Intern Orientation Week

25 January 2019

Overview •Patient blood management •Diagnostic haematology

• Diagnostic errors – pre-analytical stage • Blood film morphology reviews • Coagulation studies

•Laboratory haematology consultation service

Patient Blood Management

What do you need to know about transfusion medicine?

Specimen collection • Identification of the patient is paramount!

• Label blood tubes straight after taking the sample • Ensure the right patient’s information is on the blood tube • Incorrect labelling → Wrong blood in tube → Wrong blood

component transfused → Death or further injury to the patient • Zero tolerance for errors

AABB Transfusion Guidelines (2016)

• Red Cells • Consider the haemoglobin level, overall clinical

context and alternatives to transfusion • Variables to consider: rate of decline in Hb, volume

status, symptoms of anaemia (e.g. shortness of breath, chest pain)

• Restrictive RBC transfusion threshold: not indicated until Hb is 70g/L for hospitalised patients

• For those undergoing orthopaedic surgery, cardiac surgery or pre-existing cardiovascular disease: 80g/L

Documentation • Why are you wanting the patient transfused? What product?

Quality improvement

audits

Product reconciliation

Investigating transfusion

related events

To ensure a complete legal

record of patient’s visit

Consent

• NSW Health Policy requires informed consent prior to transfusion of any blood product

• Documented on general ‘Consent for Medical Procedure’ form, or alternate surgical procedure form (for those undergoing surgery)

• Valid for whole admission, or for 12 months for those on long-term treatment plans

• Resources to help with gaining consent on intranet page

Patient Information • Should be provided to

patients / carers when discussing consent

• Available in 15 different languages

• Downloadable on Blood Management Intranet page

** Please note that at Westmead apheresis cryo is used, which is not reflected in the protocol, so the number of units is half the specified (2 instead of 4) as apheresis cryo is twice the volume and twice the fibrinogen content as pooled cryoprecipitate

Diagnostic Haematology

Source of errors in laboratory (haematology) testing

• Analytical issues

Extra-analytical (pre- and post-) issues

Pre-analytical pitfalls lead to erroneous results

• Delays in getting test results • Unnecessary re-draws/re-tests • Increased cost • Decreased patient satisfaction • Incorrect diagnosis/treatments • Morbidity and mortality

Preanalytical issues

• Patient factors • Specimen collection

• Patient identification • Draw technique, appropriate tube and volume • Mixing

• Specimen transportation • Specimen processing

≥ 1 min

Venous stasis

Note on request form if difficult/traumatic collection!

Whole Blood: Cells + Plasma + Anticoagulant

(EDTA)

Whole Blood: Cells + Plasma + Anticoagulant

(Citrate)

↑ coagulation time

Excess citrate

& dilution

Correct Citrate: Plasma

ratio

Coagulation - Citrate (blue top) samples especially susceptible to preanalytical errors

<90% >55%

Mixing

• Insufficient mixing -> microclots • Platelet count, haematocrit, haemoglobin • Coagulation studies

• Low fibrinogen • Shortening of APTT and PT

• Excessive mixing or vigorous inversions • Haemolysis -> sample rejection

FBC & Blood Film Journey

21

Blood film review - Microscopy

Haemostasis testing • Routine coagulation

tests • PT/INR, APTT, TT,

Fibrinogen, D-Dimer • Specialised

haemostasis tests • LMWH (anti-Xa) assay • NOAC quantitative

assays* • Factor assays, factor

inhibitors, VWF, platelet function

• Thrombophilia tests

NOACs and tests of coagulation Coagulation

test Effect of

Anti-Xa NOACs (Rivaroxaban)

Anti-Xa NOACs

(Apixaban)

Anti-IIa NOACs (Dabigatran)

PT/INR ++ (+) +

APTT + (+) ++

TT - - ++

Anti-Xa ++ ++ -

Favaloro et al. Pathology 2011; 43: 682–92 Favaloro & Lippi. Biochemia Medica, 2012;22:329-41 Di Minno et al. Semin Thromb Hemost. 2013;39:840–846

Key contacts Transfusion Lab: • 57644 • Emergencies: 57700 • Senior Scientist: 57650 Laboratory Haematology Specialists: Leo Pasalic: 56352 Elizabeth Tegg: 56352 Laboratory Haematology AT on call: • pg 27150 • 0409 392 151 Jo-Anne Greaves ( Transfusion CNC): • 0427 237 562 • 57580