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Hemostasis - Definition

Hemostasis is a «delicate» balance between opposite forces which:

Maintains blood fluidity in normal blood vessels

Prevents excess bleeding (hemorrhage) when vessels are injured

A “functional” hemostasis can hence be defined as an effectivemechanism which prevents hemorrhage from an injured blood vessel,requiring the activation and interplay between many variables andeffectors. Namely:

• Blood vessels

• Platelets

• Coagulation factors

The activity of which is normally modulated and counterbalanced by manyinhibitory mechanisms, aimed to limit the extent of clotting in both termsof LOCATION and AMOUNT.

NormalitàDeficit

-

Hemorrage

Eccesso

+

Thrombosis

Hemostasis can be divided into:

• Primary hemostasis

Vessel-platelet interplay

• Secondary hemostasis

Coagulation factors

Bruising

Petechiae (hemorrhages <2 mm)

Purpura (hemorrhages 0.2-1 cm)

Ecchymoses (hemorrhages > 1cm)

Bleeding

- From gums

- After invasive procedures

- Metromenorrhagia

Hematomas

Bleeding

- In joints

- In muscles

- In other soft tissues

- GI and genitourinary tract

- CNS

Vessel-platelet interplay

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The three little pigs…

- The first little pig builds a house

of straw (paglia), but a wolf

blows it down and eats him.

- The second little pig builds a

house of furze sticks (legno),

which the wolf also blows down

and eats him.

- The third little pig builds a house

of bricks (mattoni). The wolf

fails to blow down the house.

Emostasi Secondaria

La “protezione del muro”

Platelets

Fibrin

Clotting Factors

PT

APTT

ActivationThrombin

burst

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Coagulation cascade, from a Pathology book

?????

Despite FXII being essential for

surface activation of blood

coagulation, individuals with severe

deficiencies of this clotting factor do

not experience clinically meaningful

bleeding events.

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Clotting test

Clotting test

Clotting test

PLT functional assay

Clotting test

Clotting test

Clotting (chromogenic) assay

Immuno(turbidimetric) assay

PLT functional assay

Immuno(enzymatic) assay

Immuno(enzymatic/turbidimetric) assay

Immuno(turbidimetric) assay

Genetic testing

D-dimer

- Antithrombin

- Protein C

- Protein S

- Activated Protein C resistance

- Factor V Leiden

- Prothrombin gene mutation

- Lupus anticoagulants

- Anticardiolipin antibodies

- D-dimer

Chromogenic assay

Immuno(turbidimetric) assay for free PS

Chromogenic assay

Clotting assay

Genetic testing

Genetic testing

Clotting assay(s)

Immuno(enzymatic) assay

Immuno(enzymatic) assay or immuno(turbidimetric) assay

In summary… we would need:

- Clotting assays

- Chromogenic assays

- Immuno(turbidimetric) assays

- Immuno(enzymatic) assays

- Platelet function assays

- Genetic testing

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The route towards personalized laboratory testing will be

influenced by many factors such as:

- Healthcare reforms

- Cost-containment strategies

- Consolidation of laboratories and in vitro diagnostic

testing

- Impact of new technologies and tests on the existing

laboratory organization.

Take your hemostasis lab to the next level

The ongoing revolution of diagnostic testing, squeezed

between reduced funding and increasing volumes, carries

notable implications in the way laboratory resources are

organized and coagulation tests delivered.

It is therefore predictable that the newer generation of

hemostasis analyzers may be designed to face these emerging

needs whilst maintaining a high degree in the quality of

testing.

Clotting

assays

Chromogenic

assays

Imuno

(turbidimetric)

assays

Imuno

(enzymatic)

assays

Platelet

function

assays

Moving towards the future….

Clotting

assays

Chromogenic

assays

Imuno

(turbidimetric)

assays

Imuno

(enzymatic)

assays

Platelet

function

assays

Consolidation!

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ADVANTAGES

1. Reduces unnecessary tasks/steps

2. Lowers costs

3. Improve efficiency (TAT and throughput)

4. Improve process standardization (and probably quality through MIDDLEWARE)

5. Improves tests complexity and high-volume management

6. Reduces biological risk and errors

7. Allows more accurate specimen control

8. Simplifies accreditation/certification

9. Reprofessionalization (use of scilled staff for more complex

10. tasks)

11. Better confidence from stakeholders

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Centralized management of

Hemostasis testing (Middleware)

Allow to manage workflow, monitor

quality control and support decision-

making for better patient care, all from a

single workstation.

MAIN ADVANTAGES:

1. View many analyzers status in real-

time, even from different labs

2. Minimize workflow interruptions

3. Manage analyzer quality control

more simply and efficiently

4. Compare analyzer QC

5. Support clinical decision-making by

reviewing data of patient history

6. Availability of automatic rules,

reruns and reflexes

7. Optimize operations and facilitate

accreditation (!!!)

8. Run customized reports and track

key performance indicators

WEAKNESSES & THREATS

1. Dependence on manufacturer

2. Dependence on IT

3. Reduced flexibility

4. Stat handling

5. Cost for maintenance

6. High initial investment cost

7. Overexpanding test menu

8. Loss of technical skills

9. Dependence on supplier

10. What if the system fails?

- Specimen preparation, including centrifugation, aliquoting, sorting, and consumable costs:

- 20% of total costs

- 37% of the time required for testing.

- Disposal and result reporting, including archiving

and transport of finished samples:

- 10% of total costs

- 18% of the time required for testing.

- Extra-analytical activities:

- 30% of total costs

- 45% of the time required for testing.

Error rate

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MLO, 2002

Case study: Automations impact on

productivity and turnaround time

Ralph Dadoun

Prior to automation: every coagulation sample centrifuged and

managed with no automation processes.

After automation: all coagulation specimens dropped into the inlet of the

automation system.

Outcomes:

- Statistically significant improvement in TAT (from 30 minutes to 17

minutes)

- No change in quality.

Before automation is introduced in a haemostasis

lab, the work process needs to be examined in

detail.

Only then, automation can be embedded into an

appropriate concept of:

1. Space

2. Quality

3. IT-capability

4. Staffing