Plasmapheresis: the in vitro Distribution of Heparin in Plasma and Red Cell Fractions following Centrifugation

Abstract

A modified activated partial thromboplastin time (activated PTT) technique was employed in determining heparin concentration in plasma following centrifugation of whole blood. In reference to previous studies reporting heparin to be found essentially in the plasma, it was shown in the present study that following centrifugation of each bag of whole blood in a double-pheresis procedure, the approximate heparin distribution was 39.9 and 45.7% recovery in plasma for bags 1 and 2, respectively. It is suggested that heparin binding to cellular components may account for the low recovery in plasma. Activated PTTs conducted following reinfusion of red cell concentrates into donors were within normal values, and were consistent with the suggestion that heparin is bound to cellular components in vivo. The safety of the weekly injection of approximately 3,120 USP units of heparin into donors on a long-term basis is considered in the light of extensive data avilable from widespread systemic use.

Early Hemorrhagic Progression of Traumatic Brain Contusions: Frequency, Correlation with Coagulation Disorders, and Patient Outcome: A Prospective Study

“…In our opinion, it might be insufficient to assess a TBI patient's coagulation status by merely testing for abnormalities in platelet count, INR, and PTT, especially when considering that the latter two parameters were developed to monitor warfarin dosage 25 and heparin treatment. 26 The logical consequence of such assessment would be to overlook a TIC in more than half of the TBI cases.…”