HAEMOSTATIS AND COAGULATION

Haemostasis is the arrest of bleeding following vessel injury

1) Changes in involved vessel

Formation of platelet plug

Formation of fibrin clot

Vessel vasoconstricts

Endothelium becomes 'procoagulant'

Vessels where I VSM present (not capillaries - endothelium fuses)
Mechanisms:

depolarisation of vascular smooth muscle cells
vasoactive mediators

ANTICOAGULANTS

HEPARINS

Types

LMWH (low molecular weight heparins)

Protamine

ORAL ANTICOAGULANTS

DIRECT FACTOR Xa INHIBITORS

WARFARIN

DIRECT THROMBIN INHIBITORS :

Naturally occurring heparin

UFH (Unfrationated Heparin)

Highly sulphated glycoasaminoglycan.
Anionic
MW variable = 5000-30000 Da
Production - basophils, mast cels

Chemical: synthetic. MW 5000-25000 Da
Uses: treat VTE, unstable angina, critical arterial occlusion, extracorporeal circuits (bypass, ECMO)
Action: potentiates antithrombin (III), inhibitis Xa, inhibits platelet aggregation at high levels

oute: IV infusion

Chemical: synthetic heparin MW 5000-30000 Da.

Uses:

treatment of DVT/PE
critical arterial ischaemia
extracorporeal circuits (dialysis, bypass, ECMO)

Actions:
1) potentiates Antithrombin (III) - forms inactive complex with thrombin
2) inhibits Factor Xa
3) inhibit platelet aggregation at high concentration

Dose:

Route:

Side effects:

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