The Effect of Fresh Frozen Plasma Transfusion on International Normalized Ratio in Critically Ill Patients

Introduction: Patients with mild prolongation of coagulation values are often transfused with Fresh Frozen Plasma (FFP) on the assumption that FFP will correct coagulopathy. Aim: To assess the effect of FFP transfusion on International Normalized Ratio (INR) in critically ill patients. Materials and Methods: All adult patients with a pretransfusion INR of more than 1.2 and whose post transfusion INR available within one hour of completing the transfusion were included in this analysis. Those patients receiving blood products or supplements other than Vitamin K and FFP were excluded from the analysis. Patients receiving vitamin K were included in the study since it requires four to eight hours to exert its effect. Pre-transfusion INR was categorized into three groups, mild (INR <2), moderate (INR 2-3) and severe elevation (INR >3). Post-transfusion INR results were collected from the case records and the improvement in INR per unit of FFP was calculated. The magnitude of improvement in INR per unit of FFP was also calculated and the significant improvement was measured using the formula derived by Holland and Brooks. This study was done in all critically ill patients admitted at a tertiary care centre in South India for a period of one year. Results: Percentage of patients showing significant improvement in INR was maximum (72.7%) in those patients having severe elevations in INR (INR>3) and is minimum (28.6%) in those patients with mild elevations in INR (INR<2)(p=0.031). A linear relationship was found between pre-transfusion INR and improvement in INR per unit of FFP (Pearson correlation value r=0.929, p<0.05) showing that the improvement in INR per FFP increases with patient’s pre-transfusion INR. Also found that of the total 38 patients showing significant improvement in INR, 63% were receiving therapeutic transfusions whereas only 26% were receiving prophylactic transfusions and 10.5% were receiving inappropriate transfusions for mild elevations in INR (p=0.027). A significant association was found between bleeding and improvement in INR. Those patients with bleeding showed more improvement in INR (66.6%) than those who do not (41.6%, p<0.05) Conclusion: It is concluded that prophylactic transfusion of FFP in mild and moderate prolongation of INR is of no use and this practice should be discouraged.