The ‘Primeless Pump’: A Novel Technique for Intraoperative Blood Conservation

Purpose: Hemodilution during cardiopulmonary bypass may lead to anemia requiring intraoperative transfusions. Prime removal from the cardiopulmonary bypass circuit was used to limit dilution and intraoperative transfusions. Methods: The technique of prime removal consists of arterial and then venous side evacuation of crystalloid prior to cardiopulmonary bypass. The effectiveness of this technique. to maintain a higher hematocrit and reduce intraoperative transfusions. was studied prospectively in two consecutive groups of patients undergoing coronary revascularization (controls versus primeless). Results: Intraoperative hematocrits were significantly higher (P < 0.0001) and transfusions lower (4%) in the primeless versus the control group (19%) (P = 0.003). Prime removal is of particular benefit in anemic (hematocrit :5 35%) and/or small patients (body surface area :5 2 m-), Conclusion: The technique of prime removal is simple. safe and cost-effective. reducing intraoperative transfusions. especially in small and/or anemic patients. It could be part of blood conservation strategies in most adult cardiac operations. © 1999 The International Society for CardiovascularSurgery. Published by Elsevier Science Ltd. All rights reserved.