Unusual Cause of Flank Pain

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.  
Anticoagulation reversal algorithm that Sven Olson and Joe Shatzel recently put together

Anticoagulation reversal algorithm that Sven Olson and Joe Shatzel recently put together