Thrombin generation during cardiopulmonary bypass: the possible role of retransfusion of blood aspirated from the surgical field

Anticoagulation management during pulmonary endarterectomy with cardiopulmonary bypass and deep hypothermic circulatory arrest

INTRODUCTION

Pulmonary endarterectomy requires cardiopulmonary bypass and deep hypothermic circulatory arrest, which may prolong the activated clotting time. We investigated whether activated clotting time-guided anticoagulation under these circumstances suppresses hemostatic activation.

METHODS

Individual heparin sensitivity was determined by the heparin dose-response test, and anticoagulation was monitored by the activated clotting time and heparin concentration. Perioperative hemostasis was evaluated by thromboelastometry, platelet aggregation, and several plasma coagulation markers.

RESULTS

Eighteen patients were included in this study. During cooling, tube-based activated clotting time increased from 719 (95% confidence interval = 566-872 seconds) to 1,273 (95% confidence interval = 1,136-1,410 seconds; p < 0.01) and the cartridge-based activated clotting time increased from 693 (95% confidence interval = 590-796 seconds) to 883 (95% confidence interval = 806-960 seconds; p < 0.01), while thrombin-antithrombin showed an eightfold increase. The heparin concentration showed a slightly declining trend during cardiopulmonary bypass. After protamine administration (protamine-to-heparin bolus ratio of 0.82 (0.71-0.90)), more than half of the patients showed an intrinsically activated coagulation test and intrinsically activated coagulation test without heparin effect clotting time >240 seconds. Platelet aggregation through activation of the P2Y12 (adenosine diphosphate test) and thrombin receptor (thrombin receptor activating peptide-6 test) decreased (both -33%) and PF4 levels almost doubled (from 48 (95% confidence interval = 42-53 ng/mL) to 77 (95% confidence interval = 71-82 ng/mL); p < 0.01) between weaning from cardiopulmonary bypass and 3 minutes after protamine administration.

CONCLUSION

This study shows a wide variation in individual heparin sensitivity in patients undergoing pulmonary endarterectomy with deep hypothermic circulatory arrest. Although activated clotting time-guided anticoagulation management may underestimate the level of anticoagulation and consequently result in a less profound inhibition of hemostatic activation, this study lacked power to detect adverse outcomes.

Direct autotransfusion following emergency pericardiocentesis in patients undergoing cardiac electrophysiology procedures

INTRODUCTION

Acute hemopericardium during cardiac electrophysiology (EP) procedures may result in significant blood loss and is the most common cause of procedure-related death. Matched allogeneic blood is often not immediately available. The feasibility and safety of direct autotransfusion in cardiac electrophysiology patients requiring emergency pericardiocentesis is unknown.

METHODS

We retrospectively analyzed records of patients undergoing EP procedures at a single, tertiary care medical center who had procedure-related acute hemopericardium requiring emergency pericardiocentesis during a 3-year period. Procedure details, transfusion volumes, and clinical outcomes of patients who received direct autotransfusion of aspirated pericardial blood via a femoral venous sheath were compared to those of patients who did not receive direct autotransfusion.

RESULTS

During the study period, 10 patients received direct autotransfusion (group 1) and outcomes were compared with those of 14 control patients who did not receive direct autotransfusion (group 2). The volume of aspirated pericardial blood was similar in groups 1 and 2 (1.6 ± 0.7 L vs 1.3 ± 1.0 L, respectively; P = .52). Amongst patients with aspirated volumes <1 L, group 1 patients (n = 4) were less likely than group 2 patients (n = 8) to require allotransfusion (0% vs 75%, P = .02). Amongst patients with aspirated volume ≥1 L, group 1 patients (n = 6) required fewer units of red cell allotransfusion than group 2 patients (n = 6) (1.5 ± 0.8 units vs 4.3 ± 2.0 units, P = .01). No procedural complications related to direct autotransfusion occurred.

CONCLUSIONS

Direct autotransfusion following emergency pericardiocentesis during electrophysiology procedures requiring systemic anticoagulation is feasible and safe. The utilization of direct autotransfusion may eliminate or reduce the need for allotransfusion.

Cell saver processing mitigates the negative effects of wound blood on platelet function

BACKGROUND

Wound blood is highly activated and has poor haemostatic properties. Recent data suggest that retransfusion of unwashed wound blood may impair haemostasis. We hypothesized that cell saver processing of wound blood before retransfusion reduces the negative effects.

METHODS

Wound blood was collected from 16 cardiac surgery patients during cardiopulmonary bypass. One portion of the wound blood was processed in a cell saver and one portion left unprocessed. Increasing amounts of unprocessed blood (10% and 20% of the systemic blood volume) or corresponding volumes of processed blood were added ex vivo to whole blood samples from the same patient. Clot formation was assessed by modified thromboelastometry (ROTEM(®) ) and platelet function with impedance aggregometry (Multiplate(®) ).

RESULTS

Addition of unprocessed wound blood significantly impaired clot formation and platelet aggregability. Cell saver processing before addition did not influence clot formation but abolished completely the negative effects of wound blood on platelet aggregability tested with all agonists. Median adenosine diphosphate-induced platelet aggregation was 51 (25th and 75th percentiles 42-69) when 20% processed cardiotomy suction blood was added vs. 34 (24-52) U when 20% unprocessed blood was added, P < 0.001. The corresponding figures for arachidonic acid-, thrombin receptor activating peptide- and collagen-induced aggregation was 21 (17-51) vs. 13 (10-25) U, 112 (87-128) vs. 78 (65-103) U and 58 (50-73) vs. 33 (28-44) U, respectively, all P < 0.001).

CONCLUSION

The results suggest that cell saver processing before retransfusion mitigates the negative effects of wound blood on platelet function despite that cell saver processing reduces platelet count.

The more closed the bypass system the better: a pilot study on the effects of reduction of cardiotomy suction and passive venting on hemostatic activation during on-pump coronary artery bypass grafting

Cardiac surgery with cardiopulmonary bypass (CPB) leads to a powerful activation of the hemostatic system. We assessed to what extent this activation can be attenuated by comparing three different perfusion regimens for on-pump coronary artery bypass grafting (CABG): 1) use of a closed CPB system with aspiration of blood from the operation field via the cardiotomy suction line and active venting of the heart via a roller pump; 2) use of a closed CPB system avoiding aspiration of blood from the operation field via the cardiotomy suction line, but with active venting of the heart; and 3) use of a closed system, avoidance of aspiration of blood from the operation field via the cardiotomy suction line and with passive venting of the heart into the collapsible venous reservoir. Our data show that avoidance of aspiration of blood via the cardiotomy suction line significantly reduces hemostatic activation during on-pump CABG. However, further attenuation of hemostatic activation can be achieved by further closing the system and minimizing the blood/air interface by passive venting of the heart.

Leukocyte removal efficiency of cell-washed and unwashed whole blood: an in vitro study

Leukocyte filtration of the cardiopulmonary bypass (CPB) perfusate after cardiac surgery has evolved as an important technique to prevent effector functions mediated by activated leukocytes. However, little is known about the filtration efficiency. Therefore, an in vitro study was conducted to define the leukocyte removal rate of a transfusion leukocyte-depletion filter, using cell-washed and unwashed whole porcine blood. In addition, the influence of different cell-washing protocols on the elimination rate of blood cells (leukocytes and platelets) was investigated.

Fresh, diluted, pooled, heparinized, porcine blood was processed using either a high-flow (HF, n-5) or quality-wash (QW, n-5) protocol on a continuous auto-transfusion system, or was left unprocessed (control n-5). Thereafter, all samples were filtered using a transfusion leukocyte-depletion filter. Blood samples for measurement of hematocrit, white blood cell count, including leukocyte differentiation and platelet count, were taken before and after filtration. To compare the experimental groups, the removal rate was presented as the fraction of leukocytes or platelets removed per plasma volume.

Cell washing significantly altered the fraction of leukocytes removed per plasma volume when compared to unprocessed blood (2.07 and 2.36 in the HF and QW groups, respectively, versus 1.34 in the control group, p-0.008 for both). No statistically significant difference in leukocyte removal rate was observed between the different cell-washing protocols. The leukocyte differential count showed that, during all experiments, the neutrophils were removed most efficiently (99.7%). Overall, significantly more platelets were depleted after cell washing compared to the control group (1.47 and 1.60 in the HF and QW groups, respectively, versus 1.12 in the control group, p-0.008 and 0.032, respectively). Furthermore, the amount of blood that could be filtered using a single pass technique did not significantly differ between the experimental groups. However, a larger variation in the total amount of filtered blood was observed in the unprocessed group (5709/398 mL) compared to the cell-washed groups (3609/42 and 4309/97 mL in the HF and QW groups, respectively).

In conclusion, blood processing with an auto-transfusion system significantly enhances the leukocyte and platelet removal efficiency of the transfusion leukocyte-depletion filter that was studied. In particular, neutrophils were efficiently removed.

Accelerated activation of the coagulation pathway during cardiopulmonary bypass in aortic replacement surgery: a prospective observational study

Background

Any form of surgery or tissue damage causes release of tissue factor into the circulation. This may lead to the accelerated consumption of coagulation factors, resulting in severe consumptive coagulopathy. In this study, we compared the molecular markers involved in coagulation activation during cardiopulmonary bypass (CPB) between patients who underwent aortic replacement surgery and those who underwent valve surgery.

Methods

This prospective observational study was performed in each 14 patients who underwent aortic replacement surgery or valve surgery. We evaluated the differences in the levels of fibrinogen, activated factor VII (FVIIa), thrombin–antithrombin complex (TAT), and soluble fibrin monomer complex (SFMC) during surgery between these two groups.

Results

The change in fibrinogen levels showed no difference between the groups. The magnitude of increase in TAT was much larger in patients who underwent aortic replacement surgery than in those who underwent valve surgery (173.6 vs. 49.4 ng/mL; p = 0.0001). More importantly, the elevation of FVIIa was significantly higher in patients who underwent aortic replacement (28.5 vs. 19.0 mU/mL; p = 0.0122). The magnitude of increase in SFMC was also larger in the aortic replacement surgery.

Conclusions

The activation of coagulation during CPB was dramatically higher in the aortic replacement surgery compared with the valve surgery, probably owing to the activation of the extrinsic coagulation pathway in the former. This could potentially exacerbate consumptive coagulopathy after CPB termination in patients who underwent aortic replacement, possibly resulting in massive hemorrhage due to impaired hemostasis.

Fibrinogen concentrate administration attributes to significant reductions of blood loss and transfusion requirements in thoracic aneurysm repair

Background

Repair of thoracic aortic aneurysm (TAA) is often associated with massive hemorrhage aggravated by dilutional coagulopathy with severe hypofibrinogenemia. Although only fresh frozen plasma (FFP) is available for acquired hypofibrinogenemia in Japan, the hemostatic effect of FFP has not been enough for dilutional coagulopathy in TAA surgery. There are increasing reports suggesting that fibrinogen concentrate may be effective in controlling perioperative bleeding and reducing transfusion requirements.

Methods

We retrospectively analyzed the hemostatic effect of fibrinogen concentrate compared with FFP in total 49 cases of elective TAA surgery. In 25 patients, fibrinogen concentrate was administered when the fibrinogen level was below 150 mg/dL at the cardiopulmonary bypass (CPB) termination. The recovery of fibrinogen level, blood loss, and transfused units during surgery were compared between cases of this agent and FFP (n = 24).

Results

We observed rapid increases in plasma fibrinogen level and subsequent improvement in hemostasis by administration of fibrinogen concentrate after CPB termination. The average volume of total blood loss decreased by 64% and the average number of transfused units was reduced by 58% in cases of fibrinogen concentrate given, in comparison with cases of only FFP transfused for fibrinogen supplementation.

Conclusions

In patients showing severe hypofibrinogenemia during TAA surgery, timely administration of fibrinogen concentrate just after removal from CPB is effective for hemostasis, and therefore in reducing blood loss and transfused volumes.

Platelet-dependent thrombography gives a distinct pattern of in vitro thrombin generation after surgery with cardio-pulmonary bypass: potential implications

Background

Bleeding remains a potentially lethal complication of cardio-pulmonary bypass (CPB) surgery. The purpose of this study was to obtain a better insight into in vitro thrombin generation in the context of CPB.

Methods

We used Calibrated Automated Thrombography to assess blood coagulation of 10 low-risk patients operated for valve replacement with CPB, under 2 experimental conditions, one implicating platelets as platelet dysfunction has been described to occur during CPB.

Results

Our main finding was that CPB-induced coagulopathy was differently appreciated depending on the presence or absence of platelets: the decrease in thrombin generation was much less pronounced in their presence (mean endogenous thrombin potential change values before and after CPB were -3.9% in the presence of platelets and -39.6% in their absence).

Conclusion

Our results show that experimental conditions have a profound effect in the study of in vitro thrombin generation in the context of CPB.

Formation of intracardiac thrombus during cardiopulmonary bypass despite full heparinization and adequate activated clotting time -A case report-

We reports a case of a newly formed thrombus in the left atrial appendage during cardiopulmonary bypass detected by transesophageal echocardiography in a patient with chronic atrial fibrillation and mitral stenosis. This case alerts the anesthesiologists of possible thrombus formation despite full heparinization during cardiac surgery and the importance of a comprehensive echocardiography examination.

Autotransfusion management during and after cardiopulmonary bypass alters fibrin degradation and transfusion requirements

The coagulation-fibrinolytic profile during cardiopulmonary bypass (CPB) has been widely documented. However, less information is available on the possible persistence of these alterations when autotransfusion is used in management of perioperative blood loss. This study was designed to explore the influence of autotransfusion management on intravascular fibrin degradation and postoperative transfusions. Thirty patients, undergoing elective primary isolated coronary bypass grafting, were randomly allocated either to a control group (group A; n=15) or an intervention group (group B; n=15) in which mediastinal and residual CPB blood was collected and processed by a continuous autotransfusion system before re-infusion. Intravascular fibrin degradation as indicated by D-dimer generation was measured at five specific intervals and corrected for hemodilution. In addition, chest tube drainage and need for homologous blood were monitored. D-dimer generation increased significantly during CPB in group A, from 312 to 633 vs. 291 to 356 ng/mL in group B (p = .001). The unprocessed residual blood (group A) revealed an unequivocal D-dimer elevation, 4131 +/- 1063 vs. 279 +/- 103 ng/mL for the processed residual in group B (p < .001). Consequently, in the first post-CPB period, the intravascular fibrin degradation was significantly elevated in group A compared with group B (p = .001). Twenty hours postoperatively, no significant difference in D-dimer levels was detected between both groups. However, a significant intra-group D-dimer elevation pre- vs. postoperative was noticed from 312 to 828 ng/mL in group A and from 291 to 588 ng/mL in group B (p < .01 for both). Postoperative chest tube drainage was higher in the patients from group A, which also had the highest postoperative D-dimer levels. Patients in group A perceived a higher need for transfusions of red cells suspensions postoperatively. These data clearly indicate that autotransfusion management during and after CPB suppresses early postoperative fibrin degradation.

KEYWORDS

cardiopulmonary bypass, cardiotomy suction, coronary surgery, autotransfusion, fibrin degradation.

Pump-induced platelet aggregation with subsequent hypotension: Its mechanism and prevention with clopidogrel

OBJECTIVES

Use of extracorporeal circuits in cardiopulmonary bypass and hemodialysis often causes bleeding problems and hypotension. As shown previously, this might be caused by activation of blood platelets due to pumping. The present study investigates the mechanism of pump-induced platelet aggregation and its possible prevention.

METHODS AND RESULTS

Continuous measurement of platelet aggregation in an extracorporeal shunt from a carotid to a femoral artery in rats showed that aggregation during the first 10 minutes of pumping was not reduced by coating the tube with albumin or heparin nor by using dalteparin instead of unfractionated heparin as anticoagulant. Also, pump characteristics seemed unimportant because aggregation could already be elicited by single tube compression with one pump roller. It was calculated that during compression wall shear stress in the tube rises far beyond the values known to induce platelet aggregation, occurring also in clinically used roller pumps. A crucial role for adenosine diphosphate was demonstrated by blockade of platelet adenosine diphosphate-P2Y12 receptors with the clinically used drug clopidogrel (50 mg/kg intravenously, n = 8). This prevented platelet aggregation and the fall of systemic blood pressure (to 71% +/- 12% in controls, n = 6) during 2 hours of continuous pumping.

CONCLUSION

We conclude that pump-induced platelet aggregation is not caused by factors released from the tube or its coating but is initiated by short bouts of high shear stress, and its continuation is critically dependent on adenosine diphosphate. The latter might have clinical relevance for patients connected to extracorporeal systems.

Disposition of tissue factor pathway inhibitor during cardiopulmonary bypass

BACKGROUND

The tissue factor (TF) factor (F) VIIa complex activates coagulation FIX and FX to initiate coagulation, and also cleaves protease activated receptors (PARs) to initiate inflammatory processes in vascular cells. Tissue factor pathway inhibitor (TFPI) is the only specific inhibitor of the TF-FVIIa complex, regulating both its procoagulant and pro-inflammatory properties. Upon heparin infusion during cardiopulmonary bypass (CPB), a heparin releasable pool of endothelial associated TFPI circulates in plasma. Following protamine neutralization of heparin, the plasma TFPI level decreases, but does not return completely to baseline, suggesting that during CPB a fraction of the plasma TFPI becomes heparin-independent. We have investigated the structural and functional properties of plasma TFPI during CPB to further characterize how TFPI is altered during this procedure.

METHODS

We enrolled 17 patients undergoing first-time cardiac surgery involving CPB. Plasma samples were obtained at baseline, 5 min and 1 h after start of CPB (receiving heparin), 10 min after protamine administration (off CPB) and 24 h following surgery. Samples were analyzed for full-length and free (non-lipoprotein bound) TFPI antigen by enzyme-linked immunosorbent assay (ELISA) and for TFPI anticoagulant activity using an amidolytic assay. Western blot analysis was used to identify TFPI species of varying molecular weights in three additional patients. Dunnett's test for post hoc comparisons was used for statistical analysis.

RESULTS

The ELISA and Western blot data indicated that an increase in full-length TFPI accounted for most of the heparin releasable TFPI. Following heparin neutralization with protamine, the full-length TFPI antigen returned to baseline levels while the free TFPI antigen and the total plasma TFPI activity remained elevated. This was associated with the appearance of a new 38 kDa form of plasma TFPI identified by Western blot analysis. The 38 kDa form of TFPI did not react with an antibody directed against the C-terminal region of TFPI indicating it has undergone proteolysis within this region. All TFPI measurements returned to baseline 24 h following CPB.

CONCLUSIONS

During CPB the full-length form of TFPI is the predominant form in plasma because of its prompt release from the endothelial surface following heparin administration. Upon heparin neutralization with protamine, full-length TFPI redistributes back to the endothelial surface. However, a new 38 kDa TFPI fragment is generated during CPB and remains circulating in plasma, indicating that TFPI undergoes proteolytic degradation during CPB. This degradation may result in a decrease in endothelium-associated TFPI immediately post-CPB, and may contribute to the procoagulant and proinflammatory state that often complicates CPB.

Aprotinin Shows Both Hemostatic and Antithrombotic Effects During Off-Pump Coronary Artery Bypass Grafting

BACKGROUND

Hemostatic drugs are widely thought to be unnecessary and potentially detrimental in off-pump coronary artery bypass graft surgery (OPCABG), despite well-established use in on-pump surgery. In a randomized, prospective OPCABG trial, we assessed efficacy and safety of aprotinin through a comprehensive assessment of graft patency and hematologic function.

METHODS

Sixty patients were randomly assigned to full-dose aprotinin or placebo. Heparin was titrated to a kaolin-based activated clotting time of greater than 300 seconds. Exclusionary criteria included creatinine greater than 2 mg/dL, conversion to on-pump CABG, and preoperative GPIIb/IIIa inhibition. Hematologic assessments were obtained preoperatively, at the end of surgery, and on days 1 and 3: mean platelet volume, thrombin generation (prothrombin fragment 1.2 assay), and aspirin resistance using a modified thrombelastography, whole blood aggregometry, 11-dehydro-thromboxane B2 levels, and flow cytometry. Thrombotic events were defined as postoperative myocardial infarction by electrocardiography or elevated troponin I, clinical stroke by examination and head computed tomography, and bypass graft failure by multichannel computed tomography angiography on day 5.

RESULTS

Aprotinin was associated with a significant reduction in intraoperative and postoperative blood loss compared with placebo but had no effect on transfusion rates. Patients treated with aprotinin had significantly fewer thrombotic events (3% versus 23%, p < 0.05, Fisher's exact test) and less postoperative aspirin resistance (20% versus 46%, respectively, p < 0.05, Fisher's exact test). Postoperative prothrombin fragment 1.2 level was reduced by aprotinin use.

CONCLUSIONS

Aprotinin reduced perioperative bleeding after OPCABG. Preserved aspirin sensitivity in the aprotinin group may explain the observed reduction in thrombotic events and might be related to the suppression of perioperative and transmyocardial thrombin formation.

Assessment of hemostatic activation during cardiopulmonary bypass for coronary artery bypass grafting with bivalirudin: Results of a pilot study

OBJECTIVE

Bivalirudin has been successfully used as a replacement for heparin during on-pump coronary artery bypass grafting. This study was conducted to assess the effects of the currently suggested protocol for bivalirudin on hemostatic activation during cardiopulmonary bypass with and without cardiotomy suction.

METHODS

Ten patients scheduled for coronary artery bypass grafting were enrolled. Bivalirudin was given with a bolus of 50 mg in the priming solution and 1.0 mg/kg for the patient, followed by an infusion of 2.5 mg . kg(-1) . h(-1) until 15 minutes before the conclusion of cardiopulmonary bypass. Cardiopulmonary bypass was performed with a closed system in 5 patients with and in 5 patients without the use of cardiotomy suction. Blood samples were obtained before and after cardiopulmonary bypass. D-dimers, fibrinopeptide A, prothrombin 1 and 2 fragments, thrombin-antithrombin, and factor XIIa were determined.

RESULTS

Values for factor XIIa remained almost unchanged in both groups, indicating a minor effect of contact activation. In patients without cardiotomy suction, post-cardiopulmonary bypass values for D-dimers, fibrinopeptide A, prothrombin 1 and 2 fragments, and thrombin-antithrombin were not significantly increased compared with pre-cardiopulmonary bypass values. In patients with cardiotomy suction, values obtained for these parameters had significantly increased compared with pre-cardiopulmonary bypass values and the values obtained in the group without cardiotomy suction after cardiopulmonary bypass.

CONCLUSIONS

With this protocol, hemostatic activation during cardiopulmonary bypass was almost completely attenuated when cardiotomy suction was avoided. Cardiotomy suction results in considerable activation of the coagulation system and should therefore be restricted and replaced by cell saving whenever possible.

Reinfusion of aspirated pericardial blood during CPB. Part I. Hypothesis: laparotomy sponges are a significant part of the CPB circuit?

Blood accumulating in the pericardial sac is routinely reinfused during cardiopulmonary bypass (CPB) surgery. Such reinfusion has been associated with an increased incidence of serious complications such as coagulopathy, systemic inflammation, and neurologic sequelae. We hypothesize that some of these complications occur because the reinfused blood has been exposed to and activated by laparotomy sponges used to elevate the heart during vein graft emplacement. Such laparotomy sponges expose accumulating pericardial blood to a large, raw, cotton surface with an area approximately five times that of the CPB circuit (excluding the biocompatible oxygenator membrane). Because the reinfused blood has been exposed to this surface, the sponge becomes, in essence, a significant-though inapparent-part of the CPB circuit. Steps should be taken to either eliminate the sponge or to reduce the area of this foreign surface and make it more biocompatible.

Reducing Hemostatic Activation During Cardiopulmonary Bypass: A Combined Approach

Interventions such as heparin-coated circuits, epsilon-aminocaproic acid, and reduced shed blood reinfusion have shown mixed results when applied individually for limiting hemostatic activation during cardiopulmonary bypass (CPB). We compared coagulation and fibrinolytic activation during conventional CPB (control) (CTRL) using noncoated circuits, no antifibrinolytics, and open cardiotomy with a combined strategy (HAC) that used heparin-coated circuits, epsilon-aminocaproic acid, and closed cardiotomy. Blood samples were drawn before, during, and after CPB for primary coronary bypass grafting surgery from 9 CTRL patients and 10 HAC patients. Thrombin-antithrombin complex and fibrinopeptide A levels (markers of thrombin and fibrin generation) were reduced in the HAC versus CTRL group after 30 min of CPB (P < 0.05). Average tissue plasminogen activator (tPA) levels were significantly lower in the HAC group by 30 min on CPB (P < 0.05), resulting in preservation of plasminogen activator inhibitor (PAI)-1 during CPB (P < 0.05). D-Dimer, a measure of intravascular fibrin formation and removal, was reduced in the HAC group during and after CPB (P < 0.005). Overall, the combined strategy was associated with a reduction in CPB-induced increases in markers of thrombin generation, fibrin formation, tPA release, and fibrin degradation and better preservation of PAI-1.

IMPLICATIONS

A combined approach during cardiopulmonary bypass (CPB) that uses heparin-coated circuits, epsilon-aminocaproic acid, and limited reinfusion of shed pericardial blood is associated with reduced activation of the coagulation and fibrinolytic systems that typically occurs during conventional CPB.