Effects of a Standard Dose of Fresh Frozen Plasma on Various Elevations in the International Normalized Ratio

Aim: This study aimed to determine the effects of using a standard dose of fresh frozen plasma (FFP) on the international normalized ratio (INR) of patients with various elevations in INR from using warfarin. Materials and Methods: This prospective study was conducted in the emergency department (ED) of a training and research hospital from February 2015 to January 2016 with patients who presented with elevated INRs from using warfarin. Their demographic data, clinical features, and laboratory findings, including pre-and post-transfusion INRs, were recorded. The standard dose of FFP used was 3 units of FFP (900 mL). Delta INR (Delta INR) was defined as the pre-transfusion INR minus the post-transfusion INR. Two hours after the end of the FFP transfusion, each patient's INR was measured again. Results: Thirty-two patients who received FFP and whose pre- and post-transfusion INRs were measured were included. Of these 32 patients, 23 (71%) were women, and the patients' mean age was 72.8 +/- 11.1. The mean pre-and post-transfusion levels and Delta INR were 10.6 +/- 5.3, 4.3 +/- 2.3, and 6.2 +/- 4.3, respectively. There was a strong positive correlation between high pre-transfusion INR and Delta INR (p < 0.001, r = 0.85). Regression analysis performed to estimate Delta INR after the transfusion of a standard dose of FFP found that Delta INR = 0.69x(pre-transfusion INR) -1.111 (p < 0.001). Conclusion: The present study found that using a standard dose of FFP caused varying reductions in.INRs that correlated with the pre-transfusion INR.