Heparin-induced thrombocytopenia: Difference between revisions

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#Do not give platelts (may precipitate thrombosis)
#Do not give platelts (may precipitate thrombosis)
#Start anticoagulation
#Start anticoagulation
##Consider lepirudin, argatroban, danaparoid, fondaparinux, bivalirudin
##Consider lepirudin (unless renal failure), argatroban (unless hepatobiliary disease), danaparoid, fondaparinux, bivalirudin
##Avoid warfarin
##Avoid warfarin until platelets >100


==See Also==
==See Also==

Revision as of 19:49, 14 October 2012

Background

  • Despite low plt count pt is actually hypercoagulable; bleeding is unusual
  • Pathophysiology
    • Pathologic activation / consumption of platelets due to Ab against heparin-plt complex
    • Activated platelets then cause blood clot formation
      • Platelet count falls b/c plts are bound in clots
    • Can be caused by unfrationated or LMWH (10x common in the former)
      • Occurs in 0.5-5% of pts tx'd w/ heparin
  • Thrombosis occurs in 35-75% of pts; 20-30% die w/in 1 month

Clinical Features

  • Typical
    • Symptoms begin 5-10d after initiation of heparin
      • >50% decrease in plt count (median nadir is ~60K; rarely <20K)
      • DVT or PE
      • Cerebral vein or adrenal vein thrombosis
      • Limb arterial occlusion
      • CVA
      • MI
      • Skin necrosis
  • Rapid onset
    • Symptoms begin within hours of initiation of heparin
      • Due to preexisting circulating antibody from sensitization several weeks earlier
      • Sudden drop in plt count
      • Thrombosis
      • Flushing
      • Tachycardia
      • Hypotension
      • Dyspnea
  • Delayed onset
    • Symptoms begin several days after heparin stopped
    • Severe thromboses

Treatment

  1. Discontinue all heparin products
  2. Do not give platelts (may precipitate thrombosis)
  3. Start anticoagulation
    1. Consider lepirudin (unless renal failure), argatroban (unless hepatobiliary disease), danaparoid, fondaparinux, bivalirudin
    2. Avoid warfarin until platelets >100

See Also

Dispostion

  • Admit

Source

Tintinalli