Clinical criteria for estimating likelihood of diagnosis of heparin-induced thrombocytopenia.
| Reprinted from Am J Clin Pathol. 1999;111:700 with permission. | |
| Platelets | |
| Platelet count > 120 x 103/μL before heparin therapy and < 100 x 103/μL during therapy (or decrease of at least 40%) | |
| with | |
| Thrombocytopenia resolving within 10 days after discontinuation of heparin | +2 |
| or | |
| Platelet count recovered while receiving another kind of heparin | 0 |
| Platelet count recovering while receiving the same kind of heparin | -1 |
| Thrombocytopenia not resolving after discontinuation of heparin | -2 |
| Thrombosis | |
| Arterial thrombosis without predisposing factor | +4 |
| Arterial thrombosis with possible predisposing factor | +2 |
| Venous thrombosis during high-dose heparin therapy | +2 |
| Other thrombosis | +1 |
| Rechallenge | |
| Recurrence of thrombocytopenia after reexposure to heparin | +6 |
| No recurrence of thrombocytopenia after reexposure to heparin | -1 |
| Other causes of thrombocytopenia | |
| Excluded | +2 |
| Another drug possibly responsible | 0 |
| Cause other than drug likely (e.g., sepsis) | -2 |
| Clinical Group | |
| Definite | =6 |
| Probable | 3-5 |
| Possible | 1-2 |
| Unlikely | =0 |
| Reprinted from Am J Clin Pathol. 1999;111:700 with permission. | |
| Platelets | |
| Platelet count > 120 x 103/μL before heparin therapy and < 100 x 103/μL during therapy (or decrease of at least 40%) | |
| with | |
| Thrombocytopenia resolving within 10 days after discontinuation of heparin | +2 |
| or | |
| Platelet count recovered while receiving another kind of heparin | 0 |
| Platelet count recovering while receiving the same kind of heparin | -1 |
| Thrombocytopenia not resolving after discontinuation of heparin | -2 |
| Thrombosis | |
| Arterial thrombosis without predisposing factor | +4 |
| Arterial thrombosis with possible predisposing factor | +2 |
| Venous thrombosis during high-dose heparin therapy | +2 |
| Other thrombosis | +1 |
| Rechallenge | |
| Recurrence of thrombocytopenia after reexposure to heparin | +6 |
| No recurrence of thrombocytopenia after reexposure to heparin | -1 |
| Other causes of thrombocytopenia | |
| Excluded | +2 |
| Another drug possibly responsible | 0 |
| Cause other than drug likely (e.g., sepsis) | -2 |
| Clinical Group | |
| Definite | =6 |
| Probable | 3-5 |
| Possible | 1-2 |
| Unlikely | =0 |