Easiest way to remember the Coagulation Pathway.
Normally, Factors are written in Roman numbers, but this is way easier to remember this way.
Factor 6 does not exist.
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EXTRINSIC PATHWAY:
Tissue Factor activates it.
If patient is NPO, INR goes up due to deficiency of factor 7 due to its short half life.
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Reverse INR with PO Vitamin K 2.5mg, 4 Factor Prothrombin concentrates, FFP
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PT and PTT can go up in DIC.
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INTRINSIC PATHWAY:
Tip to remember Intrinsic pathway: T E N E T [Twelve Eleven Nine Eight Ten]
7a, 8a and 9a help convert 10 –>10a
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Bleeding increases if there is a deficiency of intrinsic FACTORS 12[no bleed], 11[rarely bleeds], 9[Moderate bleeding] and 8 [severe bleeding].
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PTT goes up if there is deficiency of factors 12, 11, 9 or 8, but it gets corrected when mixed with Normal plasma as normal plasma contains these factors.
If PTT is high and it does not get corrected upon mixing normal Plasma, then suspect Antiphospholipid antibodies or lupus anticoagulant.
Usually, patients with antiphospholipid antibodies have Strokes at young age, spontaneous abortions etc.
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COMMON PATHWAY: [10–>10A, PROTHROMBIN–>THROMBIN–>FIBRINOGEN–>FIBRIN]
Tip to remember the common pathway: 10=5 x2 x1
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[PROTHROMBIN –>THROMBIN] needs 5a and 10a.
10a [Xa] inhibitors are FREEBeD:
Fondaparinux
Rivaroxaban
Edoxaban
Enoxaparin
Betrixaban
Dalteparin
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THROMBIN helps [FIBRINOGEN–>FIBRIN]
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Direct Thrombin inhibitors are BALD:
Bivalirudin
Argatroban
Lepirudin
Dabigatran
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NOACS=DTIs + Xa inhibitors
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Antidotes:
DABIGATRAN X IDARUCIZUMAB
RIVATOXABAN and APIXABAN X ANDEXANET ALFA
