Warfarin & anticoagulation Flashcards
What is the purpose of anticoagulation and WHERE
Prevent thrombus in the slow moving venous circulation
DVT/PE
What is the purpose of antiplatelets and WHERE
Prevent platelet aggregation and thrombus in the arterial circulation
(stroke)
What is the difference between arterial and venous thrombi?
Venous - high fibrin, with platelets and RBC
Arterial - mainly platelets, low fibrin
Mode of action of warfarin and duration to anticoagulant effect
vit k antagonism
48-72 hours
How far from target INR is acceptable
0.5
Target INR for AF/DVT etc
2.5
Target INR for mechanical heart valves
depends on type of valve and pt factors
When would you use target INR of 3.5
recurrent DVT/PE in pt already receiving anticoagulant with INR over 2
Duration of anticoagulant treatment for
isolated calf DVT
6 weeks
Duration of anticoagulant treatment for
VTE provoked by another factor - e.g. surgery
3 months
Transient things that may provoke VTE (4)
surgery
COC
pregnancy
plastercast
Duration of anticoagulant treatment for
unprovoked VTE
3 months at least
Advice for major bleed on warfarin
stop warfarin
phytomenidione IV
give dried prothrombin complex or if no fresh frozen plasma
Advice of INR over 8 and minor bleeding
stop warfarin
give phytomenidione IV
repeat if still too high after 24 hours
After management of INR that is too high when should warfarin be reinitiated
INR
Advice for INR over 8 and no bleeding
stop warfarin
give phytomenidione by mouth (unlicensed)
repeat if still too high after 24 hours
advice for INR 5-8 and:
- minor bleeding
- no bleeding
-minor bleeding: stop warfarin give phytomenidione IV -no bleeding withhold 1-2 doses o f warfarin and reduce subsequent mantainance dose
Adivce for bleeding at theraputic levels
investigate underlying cause e.g. renal or GI pathology
How long before surgery should warfarin be stopped
when would we give phytomenidione day before before surgery
5 days
if the INR > 1.5 give phytomen day before
when can we restart warfarin after surgery
evening of surgery or next day if all is well
if someone is considered high risk for VTE before surgery how would we manage?
And who would be considered for this?
VTE in last 3 months, AF, previous TIA, heart valve
bridge with LMWH treatment dose, stop 24 hours before and start 28 hours after
Is the risk of bleeding higher with asprin and warf or clop and warf
clop and warf
what might be a day 1 dose of warfarin
5-10mg
