FLUID ANDHEMODYNAMIC DERANGEMENTS

- PART II

SOCORRO CRUZ – YANEZ MD, FPSP

THROMBOSIS

Definition :

Formation of a solid clotted mass

( thrombus ) derived from blood elements ( vessel , platelets , CF) intravascularly in a living person.

A.K.A antemortem clot

THROMBUS

ENDOTHELIAL ATTACHMENT

LINES OF ZAHN

POSTMORTEM CLOT

• Formed extravascularly • Postmortem ( clotting after

death ) • Involves only clotting factors• “ currant jelly “ or “ chicken fat

“ clot

POST- MORTEM CLOTS

• Rubbery, gelatinous

• Forms perfect cast on vessel wall

• No attachment to endothelium

POST MORTEM CLOT

NORMAL HEMOSTASIS

Functions :1. Maintenance of blood

in a fluid, clot free state 2. Ability to produce hemostatic plug at site

of vascular injury

FACTORS OF NORMAL HEMOSTASIS

• Blood vessel/ endothelium

• Platelets

• Coagulation system

SEQUENCE OF EVENTS IN HEMOSTASIS

1.Vasoconstriction2.Primary hemostatic plug3.Secondary hemostatic

plug4.Thrombosis and anti-

thrombotic events

NORMAL HEMOSTASIS : A. VASOCONSTRICTION

•Stimulated by vascular injury

•Mediated by :a . sympathetic NS b. Endothelin secretion

                                                                                                           

BLOOD VESSEL WALL CONTRIBUTION

1. Elaboration of prothrombotic factors / substances :a. vWF- platelet binding co-factorb. extrinsic tissue factor- activates

extrinsic clotting pathwayc. Plasminogen activators

inhibitors – inhibits fibrinolysis 2. Insulation of platelets from subendothelial collagen

BLD VESSEL CONTRIBUTION Cont…

3. Elaboration of humoral factors ( endothelin) vasoconstriction

4. Role of subendothelial collagen

BLOOD VESSEL WALL CONTRIBUTION (Cont..)

5. Elaboration of anti-thrombotic substance

a. Plt aggregator inhibitors: prostacyclin , ADPase , NO

b. Anti-thrombin inhibitors : thrombomodulin, heparin

like molecule c. Fibrinolytic : t-PA

PLATELET ROLE IN HEMOSTASIS:

1. Formation of Io hemostatic plugA. Platelet adhesion

- attachment to site of injury and exposed collagen- needs vWF to bridge platelet

and collagen

2. Platelet secretion and release Alpha granules Dense bodies

- fibrinogen - ADP - fibronectin - Ca

- PDGF - histamine - PF4 - serotonin

PLATELET ROLE (cont..)

3. Platelet aggregation ( platelet to platelet interaction ) - formation of temporary

( primary ) hemostatic plug - stimulated by ADP, TXA2

thrombin

PLATELET ROLE (cont..)

4. Platelet contraction viscous metamorphosis formation of secondary

hemostatic plug mediated by octomyosin

PLATELET ROLE (cont..)

                                                                                                           

ROLE OF COAGULATION SYSTEM IN HEMOSTASIS

conversion of thrombin to fibrinogen and formation of fibrin thrombus

may be stimulated by extrinsic and intrinsic pathway

                                                                                                    

                                                             

ANTI-CLOTTING MECHANISM

• Depletion of clotting factors

• Clearance of CF by liver

• Fibrinolysis : plasmin and plasminogen

• Proteases

• Anti-thrombin

                                                                                                           

                                                                                                             

                                                                                                                

THROMBOSIS : PREDISPOSING FACTORS

1. INJURY TO ENDOTHELIUM2. ALTERATION IN NORMAL

BLOOD FLOW3. ALTERATION IN THE BLOOD

( hypercoagulable state )

Endothelial Injury :

Acute Myocardial Infarction AtherosclerosisCigarette smoking Vasculitis HypertensionHypercholesterolemia

Alterations in blood flow

Stasis AneurysmValvular stenosis /

regurgitationVascular obstructions

Hypercoagulability

Immobilization MalignancyAPASDICNephrotic syndrome Oral contraceptive use

Endothelial wall attachmentsGross and microscopic

laminations ( LINES OF ZAHN )Compositions : laminated

platelets, fibrin, RBC and WBC

THROMBUS : Morphology

THROMBUS

ENDOTHELIAL ATTACHMENT

ENDOTHELIAL ATTACHMENT W/ RBC , PLT , FIBRIN

THROMBUS : LINES OF ZAHN

LINES OF ZAHN

1

2

THROMBUS : COMPONENTS OF LAYERS 1 – Pale areas( fibrin/platelets ) 2- Red areas ( RBC,WBC ,

fibrin )

THROMBUS : COMPONENTS OF LAYERS 1 – Pale areas( fibrin/platelets ) 2- Red areas ( RBC,WBC , fibrin )

THROMBUS : Morphology

TYPES OF THROMBI :1. Mural thrombus2. Vegetations 3. Arterial / occlusive / white or

conglutination thrombi 4. Venous/phlebothrombosi/

red or coagulative thrombi

                                                                                                            

MURAL THROMBUS

MURAL THROMBUS

MURAL THROMBUS

MURAL THROMBUS

ENDOCARDIAL THROMBOTIC VEGETATION

VALVE THROMBUS

ARTERIAL / OCCLUSIVE THROMBUS

ARTERIAL THROMBUS

ARTERIAL THROMBUS , RECENT , OCCLUSIVE

THROMBOSIS WITH ORGANIZATION

THROMBUS RENAL ARTERY

Thrombi Morphology: Venous•Venous thrombi

o Usually occlusiveo Red (because they form

in stasis syndrome and have more associated enmeshed RBCs)

o Long - forming a cast of vein with markings on them from venous valves

o Red blood cells alternating with peripheral areas of fibrin

Venous Thrombi: Clinical

Lab test:D- dimer test

ARTERIAL VENOUS THROMBI THROMBI Occur site

injury/ turbulence

Retrograde growth

Prone to occlusion

Gray white thrombi

More PLT and fibrin, less RBC

Occur at site of stasis

Forward propagation

Occlusion and fragmentation

Red , stasis thrombi

More RBC content

THROMBUS : CLINICAL SIGNIFICANCE

1. Obstruction of blood flow

ischemia and infarction2. Source of thrombo-emboli

CAROTID ARTERY ANGIOGRAM- ARTERIAL OCCLUSION

GANGRENE SECONDARY TO ARTERIAL OBSTRUCTION

THROMBO-EMBOLISM

THROMBUS : OUTCOME

1. Propagation2. Lysis and resolution 3. Embolization4. Organization

                                                                                                          

                                                                                                              

THROMBO-EMBOLISM RIGHT VENTRICLE AND PULM ART

ORGANIZED THROMBUS RECANALIZED THROMBUS

RECALANIZED & ORGANIZED PTE

RECANALIZED THROMBUS

RECANALIZATION OF THROMBUS

Dissiminated Intravascular

Coagulopathy ( DIC ) Definition :

An acute, subacute or chronic thrombotic disorder occurring 2o to cx of variety of clinical dis, presenting with thrombotic ischemia , consumption coagulopathy and shock.

DIC : Disseminated intravascular coagulopathy

• AKA. Defibrination syndrome Microcirculatory thromb Consumption coagulopathy• Clinical assoc : sepsis burns snake bites shock abruption placenta AFE

retained dead fetus carcinomatosis

DIC : MORPHOLOGY

•Multiple microthrombi in diff organs ( brain, heart, lungs , kidneys, adrenals )

•Assoc ischemic / hypoxic injury to tissues

•Multiple hemorrhages

DIC

MICROTHROMBOSIS

MICROTHROMBOSIS