Bleeding time,clotting time, PT, and PTT Dr.Haya Al-Ghazali Dr.Haya Al-Ghazali.

Bleeding time,clotting time, Bleeding time,clotting time, PT, and PTTPT, and PTT

Dr.Haya Al-GhazaliDr.Haya Al-Ghazali

HemostasisHemostasis or or haemostasishaemostasis : :

is a complex process which causes is a complex process which causes the bleeding process to stop. It refers the bleeding process to stop. It refers to the process of keeping blood to the process of keeping blood within a damaged blood vessel. within a damaged blood vessel.

Hemostasis is maintained in the Hemostasis is maintained in the body via three mechanismsbody via three mechanisms: :

Vascular spasmVascular spasm - Damaged blood - Damaged blood vessels vessels constrict. .

Platelet plug formationPlatelet plug formation - - Platelets adhere to damaged endothelium to form adhere to damaged endothelium to form platelet plug (platelet plug (primary hemostasisprimary hemostasis) and ) and then degranulate. then degranulate.

Blood Blood coagulation - Clots form upon the - Clots form upon the conversion of conversion of fibrinogen to to fibrin, and its , and its addition to the platelet plug (addition to the platelet plug (secondary secondary hemostasishemostasis). ).

THE CLOTTING MECHANISM

INTRINSIC EXTRINSC

PROTHROMBIN THROMBIN

FIBRINOGEN

FIBRIN(II) (III)

(I)V

X

Tisue ThromboplastinCollagen

VII

XII

XI

IXVIII

FIBRINOLYTIC PHASEFIBRINOLYTIC PHASE

ANTICLOTTING MECHANISMS ARE ANTICLOTTING MECHANISMS ARE ACTIVATED TO ALLOW CLOT ACTIVATED TO ALLOW CLOT DISINTEGRATION AND REPAIR OF THE DISINTEGRATION AND REPAIR OF THE DAMAGED VESSEL.DAMAGED VESSEL.

HEMOSTASISHEMOSTASIS

DEPENDENT UPON:DEPENDENT UPON:

Vessel Wall IntegrityVessel Wall Integrity Adequate Numbers of PlateletsAdequate Numbers of Platelets Proper Functioning PlateletsProper Functioning Platelets Adequate Levels of Clotting FactorsAdequate Levels of Clotting Factors Proper Function of Fibrinolytic PathwayProper Function of Fibrinolytic Pathway

So What Causes Bleeding So What Causes Bleeding Disorders?Disorders?

VESSEL DEFECTSVESSEL DEFECTS

PLATELET DISORDERSPLATELET DISORDERS

FACTOR DEFICIENCIESFACTOR DEFICIENCIES

VESSEL DEFECTSVESSEL DEFECTS VITAMIN C DEFICIENCYVITAMIN C DEFICIENCY BACTERIAL & VIRAL INFECTIONSBACTERIAL & VIRAL INFECTIONS ACQUIREDACQUIRED

PLATELET DISORDERSPLATELET DISORDERS

THROMBOCYTOPENIATHROMBOCYTOPENIA (INADEQUATE NUMBER OF PLATELETS)(INADEQUATE NUMBER OF PLATELETS)

CausesCauses DRUG INDUCED DRUG INDUCED BONE MARROW FAILUREBONE MARROW FAILURE HYPERSPLENISMHYPERSPLENISM OTHER CAUSESOTHER CAUSES

THROMBOCYTOPATHYTHROMBOCYTOPATHY ) )ADEADEQUATE NUMBER BUT ABNORMAL FUNCTIONQUATE NUMBER BUT ABNORMAL FUNCTION .(.(

causescauses UREMIAUREMIA INHERITED DISORDERSINHERITED DISORDERS MYELOPROLIFERATIVE DISORDERSMYELOPROLIFERATIVE DISORDERS

DRUG INDUCED(DRUG INDUCED(ASPIRIN, NSAIDS)

FACTOR DEFICIENCIES

Inherited:1.1. HEMOPHILIA AHEMOPHILIA A

2.2. HEMOPHILIA BHEMOPHILIA B

3.3. VON VON WILLEBRANDWILLEBRAND’’S S DISEASEDISEASE

Acquired:

1.1. Anticoagulant Anticoagulant therapytherapy

2.2. Liver diseasesLiver diseases

3.3. DICDIC

LABORATORY EVALUATIONLABORATORY EVALUATION

PLATELET COUNTPLATELET COUNTBLEEDING TIME (BT)BLEEDING TIME (BT)PROTHROMBIN TIME (PT)PROTHROMBIN TIME (PT)PARTIAL THROMBOPLASTIN TIME (PTT)PARTIAL THROMBOPLASTIN TIME (PTT)THROMBIN TIME (TT)THROMBIN TIME (TT)

PLATELET COUNT (CBC)PLATELET COUNT (CBC)

NORMAL NORMAL 100,000 - 400,000100,000 - 400,000 CELLS/MMCELLS/MM33

< <100,000100,000 ThrombocytopeniaThrombocytopenia

50,00050,000 - - 100,000100,000Mild ThrombocytopeniaMild Thrombocytopenia

< <50,00050,000 Sever ThrombocytopeniaSever Thrombocytopenia

BLEEDING TIMEBLEEDING TIME

PROVIDES ASSESSMENT OF PROVIDES ASSESSMENT OF PLATELET COUNT AND FUNCTIONPLATELET COUNT AND FUNCTION

NORMAL VALUENORMAL VALUE

2-8 MINUTES2-8 MINUTES

PROTHROMBIN TIMEPROTHROMBIN TIME

Measures Effectiveness of the Extrinsic Measures Effectiveness of the Extrinsic PathwayPathway


10-15 SECS10-15 SECS

PTPT The prothrombin timeThe prothrombin time: is therefore the time required for the plasma : is therefore the time required for the plasma

to clot after an excess of thromboplastin and an optimal to clot after an excess of thromboplastin and an optimal concentration of calcium have been added.concentration of calcium have been added.

Measures the function of the Extrinsic Pathway.Measures the function of the Extrinsic Pathway. Sensitive to Factors I, II, V, VII, X.Sensitive to Factors I, II, V, VII, X.

The PT evaluates patients suspected of having an inherited or The PT evaluates patients suspected of having an inherited or acquired deficiency in these pathways.acquired deficiency in these pathways.


INTRINSIC EXTRINSC


FIBRINOGEN

FIBRIN(II) (III)

(I)V

X


VII

XII

XI

IXVIII

When is it orderedWhen is it ordered??

Used to monitor oral anticoagulant therapy (Warfarin / Used to monitor oral anticoagulant therapy (Warfarin / Coumadin).Coumadin).

When a patient who is not taking anti-coagulant drugs When a patient who is not taking anti-coagulant drugs has signs or symptoms of a bleeding disorder.has signs or symptoms of a bleeding disorder.

When a patient is to undergo an invasive medical When a patient is to undergo an invasive medical procedure, such as surgery, to ensure normal clotting procedure, such as surgery, to ensure normal clotting ability.ability.

An elevated prothrombin time may An elevated prothrombin time may indicate the presence ofindicate the presence of::

Vitamin K deficiencyVitamin K deficiency(Vitamin K is needed to make prothrombin and other clotting factors(Vitamin K is needed to make prothrombin and other clotting factors))

DIC DIC liver diseaseliver disease a deficiency in one or more of the following factors:a deficiency in one or more of the following factors:

I, II, V, VII, X.I, II, V, VII, X. Anticoagulant (warfarin)Anticoagulant (warfarin)

INRINR

A PT test may also be called an INR test.A PT test may also be called an INR test. INR (international normalized ratio) stands for a way of INR (international normalized ratio) stands for a way of

standardizing the results of prothrombin time tests, no standardizing the results of prothrombin time tests, no matter the testing method. matter the testing method.

So your doctor can understand results in the same way So your doctor can understand results in the same way even when they come from different labs and different even when they come from different labs and different test methods.test methods.

Using the INR system, treatment with (anticoagulant Using the INR system, treatment with (anticoagulant therapy) will be the same. In some labs, only the INR is therapy) will be the same. In some labs, only the INR is

reported and the PT is not reportedreported and the PT is not reported

An INR of 1.0 means that the patient PT is normal.An INR of 1.0 means that the patient PT is normal. An INR greater than 1.0 means the clotting time is An INR greater than 1.0 means the clotting time is

elevated.elevated. INR of greater than 5 or 5.5 = unacceptable high risk of INR of greater than 5 or 5.5 = unacceptable high risk of

bleeding,whereas if the INR=0.5 then there is a high bleeding,whereas if the INR=0.5 then there is a high chance of having a clot.chance of having a clot.

Normal range for a healthy person is 0.9–1.3, and for Normal range for a healthy person is 0.9–1.3, and for people on warfarin therapy, 2.0–3.0, although the target people on warfarin therapy, 2.0–3.0, although the target INR may be higher in particular situations, such as for INR may be higher in particular situations, such as for those with a mechanical heart valve.those with a mechanical heart valve.

PARTIAL THROMBOPLASTIN TIMEPARTIAL THROMBOPLASTIN TIME

Measures Effectiveness of the IntrinsicMeasures Effectiveness of the Intrinsic

PathwayPathway


25-40 SECS25-40 SECS

PTTPTT

TheThe partial thromboplastin time (PTT) orpartial thromboplastin time (PTT) or activated partial activated partial thromboplastin timethromboplastin time (aPTT(aPTT oror APTTAPTT( ( is a performance is a performance indicator measuring the efficacy of both the "intrinsic" indicator measuring the efficacy of both the "intrinsic" and the common coagulation pathways.and the common coagulation pathways.

It is also used to monitor the treatment effects withIt is also used to monitor the treatment effects with heparin a majorheparin a major anticoagulantanticoagulant. .

Kaolin cephalin clotting time (KccT) is a historic name for Kaolin cephalin clotting time (KccT) is a historic name for

the activated partial thromboplastin timethe activated partial thromboplastin time


INTRINSIC EXTRINSC


FIBRINOGEN

FIBRIN(II) (III)

(I)V

X


VII

XII

XI

IXVIII

Normal PTT times require the Normal PTT times require the presence of the following coagulation presence of the following coagulation factors:factors:

I, II, III, IV, V, VI, VIII, IX, X, XI, & XIII, II, III, IV, V, VI, VIII, IX, X, XI, & XII

When is it orderedWhen is it ordered??

When a patient presents with unexplained bleeding or When a patient presents with unexplained bleeding or bruising,bruising,

It may be ordered as part of a pre-surgical evaluation for It may be ordered as part of a pre-surgical evaluation for

bleeding tendencies,bleeding tendencies,

When a patient is on intravenous (IV) or injection heparin When a patient is on intravenous (IV) or injection heparin

therapy, the APTT is ordered at regular intervals to therapy, the APTT is ordered at regular intervals to monitor the degree of anticoagulation.monitor the degree of anticoagulation.

Prolonged APTT may indicate:Prolonged APTT may indicate:

use ofuse of heparin.heparin.

antiphospholipid antibodyantiphospholipid antibody::especiallyespecially lupus anticoagulantlupus anticoagulant, , which paradoxically increases propensity towhich paradoxically increases propensity to thrombosisthrombosis

coagulation factor deficiency ,coagulation factor deficiency ,

e.g hemophiliae.g hemophilia DICDIC Liver diseaseLiver disease


INTRINSIC EXTRINSC


FIBRINOGEN

FIBRIN(II) (III)

(I)V

X


VII

XII

XI

IXVIII

FACTOR DEFICIENCIES

Inherited:1.1. HEMOPHILIA AHEMOPHILIA A

2.2. HEMOPHILIA BHEMOPHILIA B

3.3. VON VON WILLEBRANDWILLEBRAND’’S S DISEASEDISEASE

Acquired:

1.1. Anticoagulant Anticoagulant therapytherapy

2.2. Liver diseasesLiver diseases

3.3. DICDIC

HEMOPHILIA A (Classic Hemophilia)HEMOPHILIA A (Classic Hemophilia)80-85% of all Hemophiliacs80-85% of all HemophiliacsDeficiency of Factor VIIIDeficiency of Factor VIIILab Results - Prolonged PTTLab Results - Prolonged PTT

HEMOPHILIA B (Christmas Disease)HEMOPHILIA B (Christmas Disease)10-15% of all Hemophiliacs10-15% of all HemophiliacsDeficiency of Factor IXLab Test - Prolonged PTT

VON WILLEBRANDVON WILLEBRAND’’S DISEASES DISEASEDeficiency of VWF & amount of Factor VIIIDeficiency of VWF & amount of Factor VIIIFactor VIII is bound to vWF while inactive in Factor VIII is bound to vWF while inactive in

circulation; Factor VIII degrades rapidly circulation; Factor VIII degrades rapidly when not bound to vWF when not bound to vWF

Lab Results - Prolonged BT, PTTLab Results - Prolonged BT, PTT

ANTICOAGULANTS

An anticoagulant is a substance that prevents An anticoagulant is a substance that prevents coagulation; that is, it stops blood from clotting coagulation; that is, it stops blood from clotting

This prevents deep vein thrombosis, pulmonar This prevents deep vein thrombosis, pulmonar embolism, myocardial infarction and stroke.embolism, myocardial infarction and stroke.

ANTICOAGULANTS1.1. Coumadins (Vitamin K antagonists)Coumadins (Vitamin K antagonists)

2.2. HeparinHeparin

CoumadinsCoumadins

These oral anticoagulants that antagonize the These oral anticoagulants that antagonize the effects of effects of vitamin K..

Examples include Examples include warfarin. It takes at least 48 to . It takes at least 48 to 72 hours for the anticoagulant effect to develop. 72 hours for the anticoagulant effect to develop. Where an immediate effect is required, Where an immediate effect is required, heparin must be given concomitantly. must be given concomitantly.

Monitored by PT timesMonitored by PT times These anticoagulants are used to treat patients These anticoagulants are used to treat patients

with with deep-vein thrombosis (DVT), (DVT), pulmonary embolism (PE), (PE), atrial fibrillation (AF), (AF), and mechanical and mechanical prosthetic heart valves..

HeparinHeparin

Heparin is a biological substance. Heparin is a biological substance. It works by activating It works by activating antithrombin III, which , which

blocks thrombin from clotting blood.blocks thrombin from clotting blood. Heparin Therapy is Monitored by PTT timesHeparin Therapy is Monitored by PTT times Low molecular weight heparin is a more highly is a more highly

processed product that is useful as it does not processed product that is useful as it does not require monitoring of the APTT coagulation require monitoring of the APTT coagulation parameter (it has more predictable plasma levels) parameter (it has more predictable plasma levels) and has fewer side effects. and has fewer side effects.

Liver Disease

Liver Disease can Result in Reduced Production of Coagulation Factors (I,II,V,VII,IX,X).

DICDIC

Disseminated intravascular coagulationDisseminated intravascular coagulation ( (DICDIC is a is a pathological activation ofpathological activation of coagulation) ) blood blood clotting) mechanisms that happens in response to clotting) mechanisms that happens in response to a variety of diseasesa variety of diseases

DIC leads to the formation of small blood clots DIC leads to the formation of small blood clots inside the blood vessels throughout the bodyinside the blood vessels throughout the body

The small clots also disrupt normal blood flow to The small clots also disrupt normal blood flow to organs (such as the organs (such as the kidneys), which may ), which may

malfunction as a resultmalfunction as a result

As the small clots consume coagulation proteins As the small clots consume coagulation proteins and platelets, normal coagulation is disrupted and platelets, normal coagulation is disrupted and abnormal bleeding occurs from the skin the and abnormal bleeding occurs from the skin the gastrointestinal tract, the respiratory tract and gastrointestinal tract, the respiratory tract and

surgical woundssurgical wounds.. The PT and APTT are usually very prolonged and The PT and APTT are usually very prolonged and

the fibrinogen level markedly reducedthe fibrinogen level markedly reduced High levels of fibrin degradation products, High levels of fibrin degradation products,

including including D-dimer, are found owing to the intense , are found owing to the intense fibrinolytic activity stimulated by the presence of fibrinolytic activity stimulated by the presence of

fibrin in the circulationfibrin in the circulation. .

Definitive diagnosis depends on the result of Definitive diagnosis depends on the result of DIC:DIC:

ThrombocytopeniaThrombocytopenia) ) prolonged bleeding time)prolonged bleeding time) Prolongation ofProlongation of prothrombin timeprothrombin time andand activated activated

partial thromboplastin timepartial thromboplastin time A lowA low fibrinogen concentrationfibrinogen concentration Increased levels ofIncreased levels of fibrin degradation productsfibrin degradation products

Condition Prothrombin time

Partial thromboplastin time

Bleeding time

Platelet count

Von Willebrand diseaseunaffectedprolongedprolongedunaffected

Vitamin K deficiency or Warfarinprolongedprolongedunaffectedunaffected

Uremiaunaffectedunaffectedprolongedunaffected

Haemophiliaunaffectedprolongedunaffectedunaffected

Factor V deficiencyprolongedprolongedunaffectedunaffected

Aspirinunaffectedunaffectedprolongedunaffected

Thrombocytopeniaunaffectedunaffectedprolongeddecreased

End-stage Liver failureprolongedprolongedprolongeddecreased

Disseminated intravascular coagulation

prolongedprolongedprolongeddecreased

Bernard-Soulier syndromeunaffectedunaffectedprolongeddecreased

THANK YOUTHANK YOU

Bleeding time,clotting time, PT, and PTT Dr.Haya Al-Ghazali Dr.Haya Al-Ghazali.

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Transcript of Bleeding time,clotting time, PT, and PTT Dr.Haya Al-Ghazali Dr.Haya Al-Ghazali.