RESUMO
OBJECTIVE: Heparin-induced thrombocytopenia (HIT) is the most common form of drug-induced immune-mediated thrombocytopenia. HIT may be aggravated by life-threatening arterial and venous thrombosis and, to a lesser extent, hemorrhagic complications. We investigated the incidence of thromboembolic and hemorrhagic complications in critically ill patients with the multiple organ dysfunction syndrome and HIT. DESIGN: Case-control study. SETTING: A 33-bed general intensive care unit in a university-affiliated teaching hospital. PATIENTS: Twenty consecutive patients with laboratory-proven HIT compared with 20 contemporary, consecutive patients without HIT. INTERVENTIONS: Unfractionated heparin or low-molecular-weight heparin were replaced by danaparoid sodium in patients with HIT. MEASUREMENTS AND RESULTS: Heparin-induced thrombocytopenia was proven by a positive platelet aggregation test. The HIT group consisted of 14 males and 6 females aged 65.2+/-10.8 years (mean +/- standard deviation) with APACHE II scores of 26.7+/-5.4. Thrombocytopenia less than 100 x 10(9)/l developed within 6.4+/-7.0 days. In 12 patients thrombocytopenia resolved after discontinuation of unfractionated heparin in 8.8+/-6.4 days. Arterial and venous thromboembolic complications occurred more frequently in HIT patients than in non-HIT patients (10/20 (50%) versus 0/20 (0%); chi-square p<0.001). Hemorrhagic complications also occurred more frequently in HIT patients than in non-HIT patients (17/20 (85%) versus 7/20 (35%); chi-square p=0.001). CONCLUSION: In critically ill patients with HIT, the incidence of thromboembolic complications and hemorrhagic complications was remarkably high.