Complicated heparin induced thrombocytopenia (HIT) in cardiac surgery and its medicolegal implications
Just-Viera, J.O.
Boletin de la Asociacion Medica de Puerto Rico 84(8-9): 192-197
1992
ISSN/ISBN: 0004-4849 Document Number: 702999
Repeated heparin administration in cardiac patients may result in platelet specific antibodies which agglutinate platelets and injure endothelial cells. Heparin induced thrombocytopenia (HIT) is rarely seriously complicated by thromboembolism and bleeding may result. The serious implications of this syndrome are potential extensive damage to patients and the likelihood of medicolegal action. Recent reports may mislead attorneys. The reality is that: 1. Diagnosis of HIT by exclusion in the immediate postoperative cardiac patient is most difficult and unreliable. 2. Proposed criteria to diagnose HIT in medical patients usingrelative or absolute thrombocytopenia are not accurate or applicable for open heart surgery patients in the immediate postoperative period. 3. Currently available tests to diagnose HIT based on platelet aggregonometry lack sensitivity and specificity, are not available daily in many community hospitals, and have not achieved the category of a gold standard for diagnosis. 4. Observed thrombocytopenia after open heart surgery may or may not be related to heparin. Cessation of heparin necessary to perform platelet aggregonometry carries an unavoidable inherent risk of further thromboembolic or thrombotic complications. 5. If HIT is diagnosed and heparin is discontinued, available therapy until Coumadin becomes effective cannot prevent an existing high risk period for a new thrombotic event or extension of a previous one. Aspirin, low molecular weight dextran and possibly protamine may be tried. Treatment of patients with HIT complications remains unsatisfactory at present. 6. Patients with previous heparin induced platelet antibodies who require reoperation and reexposure to heparin may have significant morbidity and mortality. Strict abstinence from heparin postoperatively is necessary. 7. Prolonged preoperative heparin treatment or heparin induced platelet antibodies may be important in heparin resistance during bypass, diminished anticoagulation during bypass, increased bleeding immediately after bypass and increased postoperative thrombotic and thromboembolic complications.
Document emailed within 1 workday
