Reversal of Anticoagulation Flashcards
Recombinant activated factor VII use
been used to treat bleeding in patients receiving UFH, LMWH, and DOACs. Most trials are small and observational. Standard dose is 90 mcg/kg, but lower doses (e.g., 18–30 mcg/kg) have been documented to be effective
Protamine UFH dose
1 mg of protamine neutralizes about 100 units of heparin.
In patients receiving an intravenous infusion of UFH, need to calculate the amount given in the past 3 hours. The total of the past hour, one-half the previous hour, and one-fourth for the hour before that. This assumes no bolus was given within the previous 8–12 hours.
Never administer more than 50 mg in a single dose outside going off cardiopulmonary bypass.
Protamine Allergy
Patients previously receiving protamine sulfate–containing insulin, (i.e., NPH) having undergone a vasectomy, or having a known sensitivity to fish are at an increased risk of having protamine antibodies and are more likely to have allergic reactions.
Can premedicate
Protamine LMWH dose
1 mg of protamine neutralizes about 100 anti-Xa units of LMWH (dalteparin or 1 mg of enoxaparin)
If the LMWH dose was given more than 8 hours before the need for reversal, give 0.5 mg of protamine for every 100 anti-Xa units
Vitamin K for warfarin reversal
Oral vitamin K can take 24–48 hours to normalize INR
IV vitamin K can take 8–12 hours to normalize the INR, with full effects not seen until 24 hours. Should be given as slow infusion instead of “push” because of concerns for allergic reactions
Subcutaneous vitamin K should be avoided because of delayed and erratic absorption
4PCC for warfarin reversal
INR 2 to less than 4: 25 units/kg (max 2500 units)
INR 4–6: 35 units/kg (max 3500 units)
INR greater than 6: 50 units/kg (max 5000 units)
Strategy for warfarin reversal in bleed
Administer vitamin K 10 mg by slow IV infusion, together with 4PCC as needed. Check INR in 12 hr, and repeat vitamin K infusion as needed until INR normalized or within therapeutic range
Strategy for warfarin reversal INR <4.5 or 4.5-10 w/o risk factors for bleeding
Omit doses of warfarin. Check INR in 3–7 days. Restart warfarin at reduced dose
Risk factors for bleeding with elevated INR
Age > 65, concurrent antiplatelet therapy, concurrent nonsteroidal anti-inflammatory drug use, history of gastrointestinal bleeding, recent surgery or trauma, high risk of fall or trauma, excessive alcohol use, renal failure, cerebrovascular disease, malignancy
Strategy for warfarin reversal INR 4.5-10 with risk factors for bleeding, or INR >10
Omit next 1–3 doses of warfarin AND Administer vitamin K 5 mg orally or 1–3 mg by slow IV infusion. Check INR in 12–24 hr. If INR still > 9, repeat administration of vitamin K. Check INR q24hr. Restart warfarin at reduced dose once therapeutic
Dabigatran reversal
idarucizumab 5 g IV once when needed for emergency surgery or urgent procedures, or in the event of life-threatening or uncontrolled bleeding
PCC dose for Direct Xa inhibitor reversal
Doses are typically 50 units/kg, though some will give 25 units/kg and then re-dose if needed. Another option, with limited data, is to use a fixed dose of 2000 units
Andexanet alfa indication
Not currently indicated for reversal of edoxaban, enoxaparin, or fondaparinux. only
indicated for life-threatening bleeding with rivaroxaban or apixaban, and not for patients requiring urgent surgery
Andexanet alfa Standard dose
400-mg intravenous bolus, followed by 4 mg/minute for 2 hours. Indicated for patients with last dose of apixaban of 5 mg or less, rivaroxaban dose 10 mg or less, or any dose of apixaban or rivaroxaban taken more than 8 hours earlier
Andexanet alfa High dose
800-mg intravenous bolus, followed by 8 mg/minute for 2 hours. Indicated for patients with last dose of apixaban of 10 mg or rivaroxaban doses of 15 mg or 20 mg taken within the past 8 hours