safe anticoagulation management using point of care dr. tony avades sr. consultant and head of...
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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
Department of Laboratory Medicine & PathologyPoint of Care Testing (POCT) Section
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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Department of Laboratory Medicine & PathologyPoint of Care Testing (POCT) Section
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
• 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
Department of Laboratory Medicine & PathologyPoint of Care Testing (POCT) Section
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
Department of Laboratory Medicine & PathologyPoint of Care Testing (POCT) Section
• 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
Department of Laboratory Medicine & PathologyPoint of Care Testing (POCT) Section
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
Department of Laboratory Medicine & PathologyPoint of Care Testing (POCT) Section
Anti Coagulation POCT
• PT/INR• ACT• TEG
Department of Laboratory Medicine & PathologyPoint of Care Testing (POCT) Section
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
Department of Laboratory Medicine & PathologyPoint of Care Testing (POCT) Section
• 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
Department of Laboratory Medicine & PathologyPoint of Care Testing (POCT) Section
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
Department of Laboratory Medicine & PathologyPoint of Care Testing (POCT) Section
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
Department of Laboratory Medicine & PathologyPoint of Care Testing (POCT) Section
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
Department of Laboratory Medicine & PathologyPoint of Care Testing (POCT) Section
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
Department of Laboratory Medicine & PathologyPoint of Care Testing (POCT) Section
ACT
• Coagulation initiated by an activator• Clot detection is change in pump driven blood
movement• Strong activator kaolin or celite
Department of Laboratory Medicine & PathologyPoint of Care Testing (POCT) Section
Why use ACT
• Monitoring hemostatsis for heparin anticoagulant therapy
Bleeding clotting
Department of Laboratory Medicine & PathologyPoint of Care Testing (POCT) Section
• 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
Department of Laboratory Medicine & PathologyPoint of Care Testing (POCT) Section
ACT• Cardiac surgery• Percutaneous coronary intervention (PCI)• Interventional cardiology• ECMO• Critical care• Interventional radiology• Electrophysiology• Vascular surgery
Department of Laboratory Medicine & PathologyPoint of Care Testing (POCT) Section
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
Department of Laboratory Medicine & PathologyPoint of Care Testing (POCT) Section
• 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
Department of Laboratory Medicine & PathologyPoint of Care Testing (POCT) Section
TEG and NICE guidelines