The influence of acute preoperative plasmapheresis on coagulation tests, fibrinolysis, blood loss and transfusion requirements in cardiac surgery.

OBJECTIVE: Withdrawal of autologous plasma and reinfusion after cardiopulmonary bypass (CPB) offers the opportunity of improving patients' haemostasis and reducing homologous blood consumption in cardiac surgery. The influence of acute, preoperative plasmapheresis (APP) on coagulation tests, fibrinolysis, blood loss and transfusion requirements was investigated in elective aortocoronary bypass patients. METHODS: Forty patients were randomized to a control or pheresis group. The pheresis group had platelet-rich plasmapheresis (PRP-group, n = 20) performed before incision and the platelet-rich plasma (PRP) was returned after CPB. The control group (n = 20) was managed without pheresis. All patients had serial coagulation studies, including prothrombin split products (F1/F2), fibrinopeptide A (FPA), protein C (PC), thrombomodulin (TM), tissue-plasminogen-activator (t-PA), plasminogen-activator-inhibitor (PAI 1), fibrinopeptide B beta 15-42 (FPB beta 15-42), haemoglobin and platelet counts determined intra- and postoperatively. Chest tube drainage and transfusion requirements were recorded. RESULTS: APP had no negative effects on the quality of PRP. The platelet count of the withdrawn autologous plasma was 239 +/- 33 x 10(9)/l. From the end of the operation (after retransfusion of autologous plasma) until the first postoperative day platelet counts were significant higher in the PRP-group (P > 0.05). Plasma concentrations of modified antithrombin III (ATM), F1/F2 and FPA increased (166-290% from baseline) and PC- and TM-antigen decreased (11-49% from baseline) to a different extent for both groups throughout CPB. t-PA-activity increased intraoperatively peaking at the end of CPB (PRP-group: 4.8 +/- 0.8 IU/ml, control-group: 8.1 +/- 2.3 IU/ml)(P > 0.05). With onset of CPB PAI-1 levels decreased and were further reduced after CPB in control patients in comparison to PRP-patients (P < 0.05). FPB beta 15-42 occurred in peak concentrations after neutralisation of heparin by protamine. Only PRP-patients showed baseline values of coagulation and fibrinolytic parameters on the next morning (P < 0.05). Total postoperative blood loss during the first 24 h was 503 +/- 251 ml (PRP-group) and 937 +/- 349 ml in the control-group (P < 0.05). None of the PRP-patients received allogeneic blood, whereas five control-patients received 11 units of packed red cells (P < 0.05). CONCLUSIONS: The findings suggest that in elective cardiac surgery heparin cannot prevent generation of both thrombin and fibrin, born throughout CPB and postoperatively. The use of PRP withdrawn immediately preoperatively is an attractive technique to reduce allogeneic blood usage and preoperative blood loss, especially in patients in whom withdrawal of autologous whole blood cannot be performed.

Experimental studies of the influence of priming solutions on the systemic activation of complement during cardiopulmonary bypass: comparison between the use of albumin, hydroxyethyl starch and HWA-138.

Cardiopulmonary bypass surgery may be complicated by a systemic inflammatory reaction, which has been ascribed to activation of complement. For such activation, the choice of priming solution for the heart-lung machine may be of importance. The peripheral blood of three groups of eight donors was exposed to albumin, hydroxyethyl starch (HES) or to HWA-138 (pentoxifylline analogue) in addition to the priming solutions. The study confirmed that activation of complement is a consistent phenomenon during cardiopulmonary bypass surgery. The concentration of the C3 activation product C3a in the plasma was significantly increased after simulated extracorporeal circulation. However there were no differences within the increase of C3a concentrations between the various priming solutions.

Blood conservation techniques and platelet function in cardiac surgery.

Postoperative alterations in platelet function induced by cardiopulmonary bypass (CPB) are of importance. The effect on platelet aggregation of three different techniques for reducing blood consumption was studied in 30 patients undergoing elective aortocoronary bypass grafting from the beginning of anesthesia until the 1st postoperative day. The patients were randomly divided into three groups, in which 1) a cell separator was used during and after CPB; 2) a hemofiltration device was used; and 3) high-dose aprotinin was used in order to reduce the need of homologous blood. A fourth group undergoing neurosurgery procedures served as a control. Platelet aggregation induced by adenosine diphosphate (concentration 0.25, 0.50, 1.0, and 2.0 microM), collagen (4 microliters/ml), and epinephrine (25 microM) was determined by the turbidimetric method. Platelet aggregation was not significantly changed in the control group, indicating that the operation itself did not impair platelet function. At the end of the operation (after retransfusion of the salvaged pump blood), the maximum aggregation and maximum gradient of aggregation induced by all three inductors were most reduced (significantly) in the cell-separator patients. On the 1st postoperative day, platelet aggregation in the hemofiltration patients and the patients treated with aprotinin had normalized. Aggregation of patients pretreated with high-dose aprotinin was not different from that of the hemofiltration patients throughout the investigation. Blood loss was significantly highest in the cell-separator group (770 +/- 400 ml on the 1st postoperative day) but was not different between the hemofiltration (390 +/- 230 ml) and the aprotinin-treated patients (260 +/- 160 ml).(ABSTRACT TRUNCATED AT 250 WORDS)

RETRACTED: Acute preoperative plasmapheresis and established blood conservation techniques.

Plasmapheresis performed weeks before an operation producing autologous plasma has proved to be of benefit in elective operations. First experiences in acute plasmapheresis, which is performed immediately before the operation, have been reported recently. When acute plasmapheresis is used in cardiac operations, however, it must be viewed in connection with other techniques for reducing blood consumption such as the Cell Saver (CS) and ultrafiltration devices. In 60 patients undergoing elective aortocoronary bypass grafting, acute plasmapheresis was performed, producing either platelet-poor plasma or platelet-rich plasma, in combination with either the Cell Saver or hemofiltration. Fluid balance during cardiopulmonary bypass was significantly lower in the hemofiltration patients. Postoperatively, none of these patients received donor blood, whereas 4 patients of the Cell-Saver groups needed packed red blood cells. AT-III, fibrinogen, the number of platelets, albumin, total protein, and colloid osmotic pressure were less compromised when hemofiltration was used in combination with acute plasmapheresis in contrast to combination with the Cell-Saver technique. Plasma hemoglobin was without differences during the investigation period, and polymorphonuclear elastase was less increased when platelet-rich plasma was produced preoperatively. On the first postoperative day, most of the differences between the groups had already disappeared. We conclude that when acute plasmapheresis is used in cardiac operations, discarding of plasma by the Cell Saver should be avoided and ultrafiltration devices should replace centrifugation techniques for blood conservation.