PF4 and Thrombocytopenia: For thrombocytopenia with platelet count drop from 72,000 per mcL to 35,000 per mcL in five days, heparin-induced thrombocytopenia workup with platelet factor 4 was sent due to a 4T score for heparin-induced thrombocytopenia of 4 with intermediate probability and came back negative. Heparin use, including for dialysis, was avoided.