Safe Anticoagulation Management using Point of Care Dr. Tony Avades Sr. Consultant and Head of Chemistry, Endocrinology and POCT Sections DLMP Department

Safe Anticoagulation Management using Point of

Care

Dr. Tony AvadesSr. Consultant and Head of Chemistry,

Endocrinology and POCT SectionsDLMP

Department of Laboratory Medicine & PathologyPoint of Care Testing (POCT) Section

Point of Care testing (POCT)

• Tests that are performed at the bedside ..near patient.. physician office = Point of care.

• All diagnostic tests evolved from Point of care• Example is urine test at the bedside> moved

to>>side room>>moved inside the lab


POCT Technology•New technological innovation is delivering

– Improved– Simple– Shorter analysis time– Smaller Devices

•Laboratory concerns– Non-lab personnel carrying out lab work– Quality Assurance– Encroaching on the lab territory

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Evolution of healthcare and laboratory medicine

Future for health care provider and POCT

Reversal of Centralization, since centralization can lengthen the diagnostic decisionBut more economically from the lab standard

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Home

Doctors clinic

Hospital

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• POCT tests designed to be used at or near the site where the patient is located, that do not require permanent dedicated space, are performed outside the physical facilities of the clinical laboratories and that is performed by non-laboratory personnel. College of American Pathologists (CAP)

Point of Care Testing


POCT HMC Policy 7211• The policy is formulated for all Hamad Medical

Corporation services and staff for the establishment of a safe and functional POCT program.

• It is for all laboratory tests approved by the POCT Coordinating and Steering Committee.

The availability of the result within minutes of asking the clinical question improves the outcome

BUT have to ensure safety and quality


• Risk is the chance of suffering harm / error and it can be estimated from the probability of the event and the severity of the harm.

• Safe POCT is achieved by application of the approved policy, procedures and practices to the task of analysing, evaluation, controlling and monitoring risk.

• Risk management of POCT activities is by validating the tests before use, trouble shooting of failed QC, performing maintenance, ensuring operators are trained, inventory control.

Defining Risk for POCT

Main risks of POCT• Unqualified lab users-Nurses

– Have minimum lab skills perform POCT testing– They are focused on patient care

• Quality Control – A liquid sample of known concentration – Preferably two levels are used to prove stability of

the testing.– It detects systemic error not random error


Role of POCT co-ordiator• Training• Competency assessment• Quality control, internal and external• Writing and reviewing the Operating procedures• Devices and inventory control• Ensuring Results are

– reported with an appropriate reference ranges– documented with patient record which are accessible by all

care giver


Anti Coagulation POCT

• PT/INR• ACT• TEG


Why do we need anticoagulant study?

Clotting is associated with disease conditionsArtificial heart valve replacementMyocardial IschaemiaAtrial fibrillation (AF) Deep Vein Thrombosis (DVT) Pulmonary embolus Hereditary disorders ~ deficiencies in blood proteins or production of antibodies that cause the blood to clot or prevent the blood from clotting


• PT = Prothrombin Time. It is a measure of how quickly blood clots.

• INR = International Normalized Ratio • The ideal target INR range will vary from person to person

depending on a variety of factors such as;• Reason for taking anticoagulants• Medical conditions• Other issues.

• The traditional way to run a PT-INR test is to have blood drawn and sent to a lab, where the test is conducted

Why Do We Need PT/INR


PT/INR• Measure of the extrinsic pathway• POCT devices strips containing thromboplastin

reagents (variable sources)• Fresh whole blood• Clot detection

– The lab uses either optical or mechanical means– POCT

• Capillary or pump-induced movement• Oscillation change of a magnetic particle• Electro-current by alteration of fluorescence


HMC POCT PT/INR devices

Instrument Manufacturer Fresh whole blood

Citrated whole blood

Citrated plasma

Sample size

CoagCheck Roche Yes No No 10 – 25ul

Hemochron ITC Yes No No 25ul


Roche CoaguChek XS ProSystem Components CoaguChek XS Pro

Handheld Base Unit*

Handheld Battery Pack*

Department of Laboratory Medicine & PathologyPoint of Care Testing (POCT) Section 19

Principle

• The CoaguChek test strip contains recombinant thromboplastin reagent.

• When the whole blood sample is applied, the reagent is solved and an electrochemical reaction takes place which is transformed into a clotting time value being displayed on the meter screen in INR values.

• The international sensitivity index (ISI) for the system has been established as 1


Hemochron


Hemochron Signature Elite Components

Department of Laboratory Medicine & PathologyPoint of Care Testing (POCT) Section 22

Hemochron Jr. Test Cuvettes

• Test type is read automatically from the cuvette. Cuvette Intended Use Specimen Reporting Unit

ACT-LR

Monitors low to moderate heparin doses up to 2.5 units/mL of blood.Used in procedures such as cardiac catherization, Extracorporeal Membrane Oxygenation (ECMO), dialysis and Pertaneous Transluminal Cornary Angioplasty.

Whole blood Celite Equivalent Seconds

ACT+

Monitors moderate to high levels of heparin (1-6 units/mL ). Unaffected by aprotinin upto 500 KIU/mL of blood, hypothermia, and hemodilution.

Whole blood Celite Equivalent Seconds


ACT

• Coagulation initiated by an activator• Clot detection is change in pump driven blood

movement• Strong activator kaolin or celite


Why use ACT

• Monitoring hemostatsis for heparin anticoagulant therapy

Bleeding clotting


• Rapid TAT• Rapidly adjust anticoagulant dose• Heparin – half life varies by patient

– Dose required varies by patient– Potency varies by lot

• Direct thrombin inhibitors – very short half life– Require immediate intervention– No antidote available


ACT• Cardiac surgery• Percutaneous coronary intervention (PCI)• Interventional cardiology• ECMO• Critical care• Interventional radiology• Electrophysiology• Vascular surgery



Challenges• Variation in tests results based on the device used• INR corrects for variation, not with ACT• End-user knowledge of the pre-analytical

variables- Training– Sample type: cap avoid messaging, arterial or venous

avoid trauma– Size: – timing of collection-immediately

• Quality assurancesDepartment of Laboratory Medicine & Pathology

Point of Care Testing (POCT) Section

• TEG measures viscoelastic properties (viscosity) of whole blood.

• The clot viscoelasticity depends on– Fibrinogen– Platelets– Coagulation– Fibrinolytic proteins

Thromboelastograph (TEG)

TEGTEG- abnormal hemostasis and fibronolysis• Hepatic disease• Cardiac Surgery• ECMO• Assessment of bleeding peri-operatively and following trauma


• Viscoelastometric POC MAY be useful to help determine if bleeding is because of a problem with the blood’s ability to clot, or because of a surgical bleed. This helps the right treatment to stop the bleeding.

• Using these systems MAY mean that patients are less likely to need a blood transfusion during surgery or need more operations to investigate further bleeding.

• TEG is recommended to help monitor blood clotting during and after heart surgery by healthcare professionals who have had appropriate training

NICE August 2014


TEG and NICE guidelines

THANK YOU


Documents

Safe Anticoagulation Management using Point of Care Dr. Tony Avades Sr. Consultant and Head of Chemistry, Endocrinology and POCT Sections DLMP Department