HEMOSTATIC FACTORS AND REPLACEMENT OF MAJOR BLOOD-LOSS WITH PLASMA-POOR RED-CELL CONCENTRATES

The purpose of this study was to assess the change of platelet and fib rinogen concentrations and the change of activities of prothrombin and factors V and VII when major surgical blood loss was replaced with pl asma-poor red cell concentrates (RCCs) and colloid plasma substitutes. Sixty patients were studied. The average blood loss was 65% +/- 41% o f the calculated blood volume (CBV). Blood loss was monitored carefull y and replaced without delay to ensure stable blood volume. Blood samp les were obtained at the induction of anesthesia and at the end of the recovery room period, or before the patient was given fresh frozen pl asma. In addition, a platelet count was determined after each 20% bloo d loss. The results were converted to relative values, and simple Line ar regression with logarithmic transformation was applied. The initial platelet concentration was 257 +/- 89 x 10(3)/mm(3) and the extrapola tion of the regression line intercepted the critical level of 50 x 10( 3)/mm(3) at 230% (confidence interval 169%-294%) blood loss. The initi al fibrinogen concentration was 3.7 +/- 1.1 g/L and the hemostatically significant level of 1.0 g/L was already reached at 142% (117%-169%) blood loss (r(2) = 0.90). Activities of prothrombin and coagulation fa ctors V and VII reached their critical levels at 201% (160%-244%), 229 % (167%-300%), and 236% (198%-277%) blood loss, respectively. We concl ude that deficiency of fibrinogen develops earlier than any other hemo static abnormality when plasma-poor RCCs are used for the replacement of major blood loss.