Beware of the PE- further information on treatment.

Today we discussed PE, but we ran out of time to discuss a few issues in greater detail.

ISSUE: Treatment of DVT/PE with respect to Anticoagulation

The American College of Chest Physicians (ACCP) recommends the following for parenteral anticoagulants for initial treatment in PE: LMWH (i.e. dalteprain), fondaparinux, UFH)

The ACCP suggests LMWH or fondiparinux instead of UFH (Grade 2B-C suggestions); caveats include those who may not absorb subcutaneous medication adequately (i.e. anasarca) and those being considered for thrombolytics* (in these patients, consider UFH instead)

Examples:

Heparin (UFH): 5000 Units IV bolus, followed by 18 U/Kg/h (1000 U/h); can also start warfarin the same day

·       Safe in renal failure (Use when CrCl<30 ml/min)

·       Can use in pregnancy, but LMWH is preferred

·       Preferred if: persistent hypotension (more experience in trials), increased bleeding risk (short-acting, reverse with protamine sulfate), concern regarding subcutaneous absorption (i.e. obesity, anasarca—IV form bypasses this!), consideration of thrombolysis

Dalteparin (LMWH): 200 units/kg SC once daily.

·       Safe and preferred in pregnancy

·       Renal failure: half-life is increased in patients with renal failure, thus, use with caution. We typically use UFH instead in the setting of renal insufficiency

Warfarin: transition to this from UFH/LMWH; it is a vitamin K antagonist (Vit K dependent factors =II, VII, IX, X)

·       Initiation: begin on the same day as parenteral anticoagulation

·       Overlap with parenteral anticoagulation for 5 days, until INR therapeutic, b/w 2-3 for >24h

o   Rationale: warfarin impairs production of VK dep clotting factors, thus, it’s anti-coagulant effect is not realized until the clotting factors are cleared; it also decreased protein C and S levels initially; it takes ~5d for the intrinsic clotting pathway to be sufficiently suppressed

·       Dose: 3-5 mg PO daily

Alternatives to Warfarin exist…an example is Rivaroxaban (Xarelto), a Factor Xa inhibitor

·       15 mg PO BID with food* for 3 weeks, followed by 20 mg PO daily with food

·       The American College of Chest Physicians (ACCP) recommends anticoagulation treatment for 3 months in patients with provoked DVT/PE or ≥3 months if unprovoked DVT/PE

·       Canadian labeling: continuation of treatment for 3 months if first episode of DVT/PE and secondary to a transient risk factor (i.e. recent trauma, surgery, immobility), and use an extended duration of treatment if the patient has permanent risk factors for idiopathic DVT/PE

ISSUE: Alternative Treatments (non-anticoagulation)

-Thrombolytics: consider if hemodynamically unstable or life-threatening PE

-Surgical: embolectomy, to be considered it thrombolysis has failed or if the patient is hemodynamically unstable

-Insertion of IVC Filter: if anticoagulation is C/I