DVT/prophylaxis Flashcards
What is Virchow’s Triad?
Endostasis
Hypercoaguable State
endothelial damage
** ankle fusion require immobilization, strained vasulature etc
Is prophylaxis for DVT routinely recommended for foot surgeries?
NO! usually unnecessary.
Bigger cases, probably warranted.
What warrants the use of DVT prophylaxis in patients?
- major rearfoot and ankle cases >2 hours to perform
- usually thigh cuffs are used
also a surgery usually in older and obese patients.
What are mechanical modalities used to reduce likelihood of DVT?
- early ambulation
- graduated compression stockings
- intermittent pneumatic compression devices
- elevation of leg
Why is spinal and epidural anesthesia a way to reduce DVT risk?
They inhibit sympathetics and therefore result in vasodilation of the vessels = increasing blood flow to extremities.
What factors does Heparin inhibit?
Factor 2, 10a, 11a, and 12a. It potentiates the effects of antithrombin 3.
- Monitored by PTT ( intrinsic pathway)
- IV admin, used on inpatents
Why is LMWH more adventageous?
Less affinity to bind circulating proteins
- less incidence of bleeding and monitoring is not necessary
- this can be given to outpatients
- 40mg given 12-24 hours prior to surgery and continued for 7-10d or until INR is normal.
** 70% reduced risk of DVT in comparison to placebo.
What is Fondaaparinux?
This is a synthetic analogue of heparin and LMWH.
Selectively inhibits factor 10.
No risk for thrombocytopenia
What factors does Warfarin inhbit?
Factors 2, 7, 11, 10 and Protein C and S Extrinsic cascase. PT and INR. Specifically inhibits binding of Vit K 36-72 hours until peak effect occurs INR must be between 2-3 You can start warfarin immediately post op (5-10mg and continued with 5mg until proper INR reached).
Why is Warfarin and Heparin often used in combination?
Heparin has more immediate action and can be used to bridge between the time until warfarin is working.
Then once the INR is therapeutic the heparin can be discontinued.
These meds are ordered and managed by pt PCP. Often pt will be kept on these meds until they are WB after surgery.
What is an inexpensive DVT prophylaxis med?
ASPIRIN: 325 mg 1-2x a day.
continue until the patient is WB.
When do you NEVER want to use pharmaco prophylaxis for DVT?
Previous cerebral hemorrhage stroke in the last 6 months intestinal or GI bleed in last 6 months coagulopathy thrombocytopenia active intracranial lesions or neoplasms proliferative retinopathy
ABSOLUTE contraindications: active hemorrhage HITS No warfarin used in pregnancy severe trauma to head or spinal cords Spinal or epidural anesthesia ( however you can use aspirin in these situations)
