Clotting

Question 1

what is vircow’s triangle?

Answer 1

venous stasis, vascular injury, and hypercoagulability

Question 2

how do you diagnose a DVT?

Answer 2

Risk factors:
- recent trauma
- immobility
- family hx
- active cancer
- thrombophilia

Clinical:
- tenderness
- erythema
- unilateral swelling >3cm
- vein distension

Diagnosis
wells score - based on risk factors

If DVT likely
- doppler ultrasound
- interim anticoag

If DVT unlikey
- d-dimer +/- doppler
- interim anticoag

Baseline bloods when starting
FBC, UE, LFT and clotting

Question 3

what is the treatment of a DVT?

Answer 3

Interim anticoagulant
- apixaban/ rivaroxaban
- or LMWH for 5 days

Permanent anticoag

Question 4

what is your thromboprophylatic protocol for THR/ TKR?

Answer 4

NICE guidelines 2018
VTE prophylaxis is risk out weighs benefit

THR
- LMWH for 10days then aspirin 150mg for 28days
- LMWH for 28days and teds
- rivaroxaban

TKR
- aspirin 14 days (75 or 150mg)
- LMWH - 14 days with teds
- rivaroxaban or apixaban

Question 5

Draw the clotting cascade?

Question 6

what are the endogenous anticoagulants?

Answer 6

• plasmin
• antithrombin 3

Question 7

how does tranexamic acid work?

Answer 7

prevents conversion of plasminogen to plasmin

Question 8

what is the CRASH 2 trial?

Answer 8

RCT
placebo vs TXA
deaths by 4 weeks for injury from bleeding trauma
- 1g in 10mins
- 1g in 8hrs infusion

reduces deaths from bleeding trauma

Question 9

what clotting factor does rivaroxaban/ apixaban and dabigatran work on?

Answer 9

clotting factor 10a
common pathway
direct inhibitors

Question 10

how does aspirin work?

Answer 10

• COX 1 and 2 inhibitor - reduces inflammation
• impairs platelet aggregation via inhibition of platelet thromboxane A2 synthesis
• reduces thrombus formation

Question 11

how does clopidogrel work?

Answer 11

platelet inhibitor

Question 12

how does warfarin work?

Answer 12

vitamin K antagonist
factors 2,7,9 and 10