The ability of the Haemonetics® 4 Cell Saver System to remove tissue factor from blood contaminated with amniotic fluid

The purpose of this study was to determine whether functionally active tissue factor could be removed from blood contaminated with amniotic fluid (AF) after processing through a Haemonetics® 4 Cell Saver System (Haemonetics Corporation, Braintree, MA). In Phase I, AF was collected from 29 women undergoing cesarean section. Nine experiments were performed. Forty- milliliter aliquots of pooled AF were mixed with 125 mL of packed red blood cells and processed in the Cell Saver. In Phase II, all the blood and AF lost at cesarean section was collected and processed through the Cell Saver. Pre- and postwash specimens were collected and analyzed for total tissue factor concentration and the concentration of functionally active tissue factor. In Phase I, total tissue factor concentration was reduced by 89%, and the concentration of active tissue factor was reduced to 0 after processing. In Phase II, no tissue factor was detected after processing through the Cell Saver. We have demonstrated the ability of the Haemonetics® 4 Cell Saver System to remove tissue factor activity from blood contaminated with AF. Implications: Hemorrhage after childbirth may require massive transfusion. If the patient's own blood can be collected and given back to the patient, this may avoid the use of regular banked blood. Amniotic fluid, which may mix with blood lost after delivery, contains tissue factor, a substance that may activate the coagulation system and cause further bleeding. The authors found that the Haemonetics® 4 Cell Saver System (Haemonetics Corporation, Braintree, MA), which collects and washes blood, can remove tissue factor from blood contaminated with amniotic fluid.