The Effect of Washing Red Blood Cells on Post Heart Surgery Blood Loss
Condition: Cardiopulmonary Bypass
MeSH terms: Hemorrhage
Study type: Interventional
Phase: Phase 3

Summary: 
      When a child undergoes heart surgery, a heart lung machine is used to keep blood flowing
      while the child's own heart is stopped. After surgery, a significant amount of the child's
      own blood is left in this machine. In the case of small children, the relative amount of
      blood potentially lost to the child in this way is very large.

      In older children, and those who have undergone less complicated surgery, this blood can all
      returned to the child. Giving the child back his or her own blood makes is less likely that
      the child will need a transfusion of donated blood.

      However, in younger children, or in children who have undergone more complicated surgery,
      most or all of this blood is thrown away. This is because of worry that returning this blood
      may cause bleeding, and excessive bleeding is one of the most feared complications of heart
      surgery.

      This project will explore a method whereby the red blood cells left in the heart lung machine
      can be returned to children without increasing the risk of bleeding. It will also carefully
      examine the exact causes of higher bleeding risk in children getting their own blood back so
      that in the future, all children can have their own blood returned at the end of surgery.
    

Detailed description: 
      The primary hypothesis of this study is that in our study population, compared to re-infusion
      of residual CPB blood, re-infusion of only the red cell component of residual CPB blood,
      causes a lesser defect in clotting, leading to decreased hemorrhage and less post-operative
      blood loss.

      The secondary objectives of this project are to document the effects on the clotting system
      of pump blood re-infusion by means of in laboratory testing. This work has not been done and
      is of crucial importance to future optimization of the use of pump blood. We expect to detect
      and quantify with significant accuracy any increased bleeding risk with our hemostatic
      profiling. This information will be invaluable in planning the safe introduction of residual
      CPB blood re-infusion smaller children and those with increase risk of postoperative blood
      loss. Furthermore, we will determine whether or not any of the potentially beneficial effects
      to the clotting system of returning all components of residual CPB blood, such as an increase
      in functioning platelets, or an increase in clotting factors, are realized. This information
      will determine the utility of pursuing means by which these non red cell components of
      residual CPB blood can be safely re-infused.

      Induction of anesthesia, arterial and venous vascular catheter placement, heparin
      administration, cardiopulmonary bypass machine setup and priming, conduct of CPB,
      ultrafiltration of blood during CPB, post-CPB protamine administration and post-CPB blood
      ultrafiltration will all be standardized as per current clinical practice.

      Residual CPB blood will be processed and re-infused according to group allocation.

      Intravascular volume in the form of crystalloid, and blood products will be administered over
      and above the study residual blood product infusion as required according to protocol.

      Subjects will have blood sampled for hemoglobin concentration immediately after induction of
      anesthesia and again 24 hours following their surgery.

      Arterial blood will be sampled from the patient for a hemostatic profile, outlined in the
      adjacent text box, after separation from CPB and prior to initiation of residual CPB blood
      product re-infusion. A second sample will be obtained when re-infusion of residual CPB blood
      product is complete. In addition, a hemostatic profile will be run directly on a sample of
      the residual CPB blood product.

      Subject demographic data, surgical diagnosis and procedures, CPB data, all medication, blood
      product and intravenous fluid administration, total volume of study fluid administered, blood
      lost during surgery to sponges and suction and 24 hour mediastinal drainage will be recorded
      for all subjects. Any cases of incomplete re-infusion of study blood product will be noted as
      will the reason for the occurrence.
    

Intervention name(s): Residual pump blood management post aortic cannula removal; Residual pump blood management post aortic cannula removal
Intervention type(s): Procedure; Procedure
Intervention description(s): Residual pump blood will be maximally hemoconcentrated by further ultrafiltation within the CPB machine. Resulting hematocrit will be approximately 0.4. The total residual pump blood volume, approximately 300ml, will be reinfused over one hour, beginning 15 minutes after removal of the aortic cross clamp. Additional protamine sulfate will be given every 30 minutes during the infusion, .03 mg/ml of residual pump blood. Procedures in this group do not deviate from current standard practice.; All residual pump blood will be processed with a bedside red cell washing device (Cell Saver). The resulting total volume of concentrated red cells will be infused over one hour, beginning 15 minutes after removal of the aortic cross clamp. Administration of additional protamine is not required due to the low concentrations of heparin in the resulting product.
Allocation: Randomized
Intervention model: Single Group Assignment
Masking: None (Open Label)
Primary purpose: Treatment
Keywords: CPB; red blood cell washing