Hubungan kadar Hb praoperasi, jumlah perdarahan, gangguan hemodinamik, perkiraan allowable blood loss terhadap jumlah transfusi intraoperatif di RSCM tahun 2020 = The association of preoperative hemoglobin, blood loss volume, estimated allowable blood loss, hemodynamic instability with intraoperative blood transfusion volume in dr. Ciptomangunkusumo National Hospital 2020