Today we discussed a case of an elderly woman with recent DVT on therapeutic enoxaparin presenting with L flank pain who had a an acute drop in hemoglobin and hemodynamic changes, found to have a large soft tissue hematoma in the left flank area. A few learning points from the case:
1) The etiology for LEFT flank pain can be broken down into an anatomic format:
- Renal: pyelonephritis (most common cause), nephrolithiasis, hydronephrosis/obstruction, malignancy (renal, bladder, sometimes lymphoma)
- Musculoskeletal: strain, trauma, particularly rib fractures
- Pulmonary: lower lobe pneumonia or empyema, malignancy, embolism (PE)
- Vascular: AAA, renal aneurysm, renal infarction
- Spleen: rupture, abscess, infarct
- Referred: pancreas, stomach (PUD, etc)
- Right sided pain may evoke hepatobiliary sources
2) Reversal of anticoagulation depends on the agent and the clinical scenario:
- For patients on heparin products:
- If life-threatening bleed, obviously hold heparin and reverse with protamine sulfate
- If on LMWH such as enoxaparin, protamine can be used to reverse, but doesn't abolish all anti-Xa activity. Use 1mg per mg of enoxaparin if given in the last eight hours. If given greater than 8 hours ago, give 0.5mg/ mg enoxaparin.
- For patients on warfarin:
- If supratherapeutic INRs, if no bleeding, simply hold warfarin
- If supratherapeutic and minor bleeding, hold warfarin and consider vitamin K
- If supratherapeutic and major bleeding, give prothrombin complex concentrate (PCC; factors II, XII, IX, X) ~2000 U and 10mg IV vitamin K (given long half life of warfarin)
- For patients on novel oral anticoagulants (NOACs):
- For patients on dabigatran (direct thrombin inhibitor, half life ~12 hours) with major bleeding, consider monoclonal antibody, idarucizmab. Also can give PCC, transexamic acid, and consider activated charcoal if given in the last 2 hours or even hemodialysis.
- For patients on rivaroxaban or apixiban (Xa inhibitors; half lives 5-9 and 8-12 hours respectively), consider PCC.
- Consider giving platelets to patients on anti-platelet agents such as aspirin or clopidogrel as even though they have normal platelet counts often, these platelets are ineffective.