عنوان مقاله [English]
Background: Current data suggests that basal hemoglobin of 12 mg/dl is suitable for practicing Acute Normovolemic Hemodilution (ANH), during operations not necessitating cardiopulmonary bypass. This level seems to be too low when using CPB, complicating this procedure.Methods: To study the relationship between Hb level before ANH and baseline level of hemoglobin, 581 patients were investigated during cardiopulmonary bypass in elective coronary artery bypass graft (CABG) surgery. Convenient sampling method was used. Repeated measurements of hemoglobin level were done during the operation.Finding: The mean of baseline hemoglobin, first hemoglobin after going on-pomp, nadir hemoglobin during pomp, and hemoglobin during pomp for patients underwent ANH was 15.18, 8.38, 7.8 and 8.2 mg/dl respectively and 13.1, 7.7, 7.2, and 7.6 mg/dl for patients who did not undergo ANH. There was significant correlation between basal and first Hb hemoglobin going on-pomp, nadir hemoglobin during pomp and mean hemoglobin during pomp in both ANH and no-ANH groups (P < 0.001). There was significant difference between results of current formula to predetermine nadir hemoglobin, and our actual nadir hemoglobin obtained from patients. Minimum level of suitable basal hemoglobin for practicing ANH (450 ml) during on-pomp CABG, was calculated to be 14.55 mg/dl (sensitivity: 77%, specificity: 70%, and AUC: 0.805) and 12.95 mg/dl (sensitivity: 71%, specificity: 64%, and AUC: 0.686) for on-pomp CABG without ANH.Conclusion: Basal hemoglobin for practicing ANH during on-pomp surgery, somehow, depends on threshold hemoglobin for blood transfusion and acceptance of advantages and disadvantages of ANH and its complications by physician and patient.