Heparin-induced thrombocytopenia, or HIT, occurs after administration of heparin, a commonly used blood thinner. Two forms of HIT can occur. The first, Type I HIT, which affects 10 percent of those receiving heparin, causes a transient drop in platelets but has no long term effects. Type II HIT, caused by development of antibodies, occurs in 5 percent of people taking heparin and has serious, life-threatening complications, reports Roger Riley, M.D of Virginia Commonwealth University. Onset may be rapid or delayed up to five to 10 days after administration.
Death or Permanent Disability
Thrombosis, which can develop in veins or arteries, is the most serious complication of Type II HIT. Paradoxically, antibodies to heparin stick to a platelet heparin complex, causing blood to clot rather than to become thinner, according to PDR Health. Clots develop more frequently in veins than arteries but can develop in both. Type II HIT leads to death 20 to 30 percent of the time and leads to permanent disability in another 20 to 30 percent of patients, warns Massimo Franchini in the 2005 Thrombosis Journal.
Mental Changes
Heparin-induced thrombocytopenia can lead to temporary global amnesia within minutes to hours of administration. Stroke, a common complication of thrombosis, can cause slurred speech, difficulty speaking, sleepiness or problems thinking.
Respiratory Complications
Approximately 50 percent of patients develop pulmonary embolism, lead author Professor Andreas Greinacher reports in Orphanet Encyclopedia. Symptoms include shortness of breath, chest tightness, difficult or rapid breathing, coughing up blood and possible collapse and sudden death.
Limb Amputation
Around 20 percent of patients with heparin-induced thrombocytopenia undergo limb amputation after clot formation in major blood vessels leading to limb gangrene, Brown University reported in a 2008 article by Christopher DiGiovanni, M.D.
Heart Complications
Cardiac complications of heparin-induced thrombocytopenia include heart attack, cardiac arrest, tachycardia, or rapid heartbeat and high or low blood pressure.
Organ Failure
Around 30 percent experience multisystem organ failure, DiGiovanni reports, which can lead to death.
Skin Complications
Skin necrosis at the site of heparin injection or bolus can occur as a complication of Type II HIT, DiGiovanni reports. Flushing, bluish, red or black discoloration of the skin, rashes or skin sores may also occur, according to PDR Health. Redness, swelling or tenderness over the skin can indicate deep vein thrombosis.
References
- Thrombosis Journal: Heparin-Induced Thrombocytopenia---An Update: Massimo Franchini; 2005
- PDR Health: Heparin-Induced Thrombocytopenia
- Virginia Commonwealth University: Heparin-Induced Thrombocytopenia FAQs
- Brown University: Heparin-Induced Thrombocytopenia; Christopher DiGiovanni, M.D.
- Orphanet: Heparin-Induced Thrombocytopenia; Andreas Greinacher
