Stretchy electronics promise speedier heart surgery

SummaryThe tissue-type plasminogen activator related fibrinolytic system was studied in 24 patients undergoing cardiopulmonary bypass surgery. The degradation of fibrinogen and fibrin was followed during and after surgery by means of new sensitive and specific assays and the changes were related to the blood loss measured in the chest tube drain during the first 24 postoperative hours. Although tissue-type plasminogen activator was significantly released into the circulation during the period of extracor-poreal circulation (p <0.01), constantly low levels of fibrinogen degradation products indicated that a systemic generation of plasmin could be controlled by the naturally occurring inhibitors. Following extracorporeal circulation heparin was neutralized by protamine chloride, and in relation to the subsequent generation of fibrin, there was a short period with increased concentrations of fibrinogen degradation products (p <0.01) and a prolonged period of degradation of cross-linked fibrin, as detected by increased concentrations of D-Dimer until 24 h after surgery (p <0.01). Patients with a higher than the median blood loss (520 ml) in the chest tube drain had a significantly higher increase of D-Dimer than patients with a lower than the median blood loss (p <0.05).We conclude that the incorporation of tissue-type plasminogen activator into fibrin and the in situ activation of plasminogen enhance local fibrinolysis, thereby increasing the risk of bleeding in patients undergoing open heart surgery

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The Hemostatic Mechanism after Open-Heart Surgery

Thrombosis and Haemostasis ◽

10.1055/s-0038-1646707 ◽

1978 ◽

Vol 39 (02) ◽

pp. 474-487 ◽

Cited By ~ 2

Author(s):

E R Cole ◽

F Bachmann ◽

C A Curry ◽

D Roby

Keyword(s):

Extracorporeal Circulation ◽

Heart Surgery ◽

Polyacrylamide Gel Electrophoresis ◽

Open Heart Surgery ◽

Coagulation System ◽

Open Heart ◽

Time Activity ◽

Post Surgery ◽

Plasma Fractions ◽

The Mean

SummaryA prospective study in 13 patients undergoing open-heart surgery with extracorporeal circulation revealed a marked decrease of the mean one-stage prothrombin time activity from 88% to 54% (p <0.005) but lesser decreases of factors I, II, V, VII and X. This apparent discrepancy was due to the appearance of an inhibitor of the extrinsic coagulation system, termed PEC (Protein after Extracorporeal Circulation). The mean plasma PEC level rose from 0.05 U/ml pre-surgery to 0.65 U/ml post-surgery (p <0.0005), and was accompanied by the appearance of additional proteins as evidenced by disc polyacrylamide gel electrophoresis of plasma fractions (p <0.0005). The observed increases of PEC, appearance of abnormal protein bands and concomitant increases of LDH and SGOT suggest that the release of an inhibitor of the coagulation system (similar or identical to PIVKA) may be due to hypoxic liver damage during extracorporeal circulation.

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Blood Coagulation Studies and Extracorporeal Circulation in Man

Thrombosis and Haemostasis ◽

10.1055/s-0038-1655073 ◽

1967 ◽

Vol 18 (03/04) ◽

pp. 634-646 ◽

Cited By ~ 6

Author(s):

N Thurnherr

Keyword(s):

Blood Coagulation ◽

Extracorporeal Circulation ◽

Blood Clotting ◽

Heart Surgery ◽

Open Heart Surgery ◽

Fibrinolytic System ◽

Open Heart ◽

Clotting Factors ◽

Blood Clotting Factors

SummaryBlood clotting investigations have been executed in 25 patients who have undergone open heart surgery with extracorporeal circulation. A description of alterations in the activity of blood clotting factors, the fibrinolytic system, prothrombin consumption and platelets during several phases of the operation is given.

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Monitoring of r-Hirudin Anticoagulation during Cardiopulmonary Bypass – Assessment of the Whole Blood Ecarin Clotting Time

Thrombosis and Haemostasis ◽

10.1055/s-0038-1656078 ◽

1997 ◽

Vol 77 (05) ◽

pp. 0920-0925 ◽

Cited By ~ 139

Author(s):

Bernd Pötzsch ◽

Katharina Madlener ◽

Christoph Seelig ◽

Christian F Riess ◽

Andreas Greinacher ◽

...

Keyword(s):

Cardiopulmonary Bypass ◽

Whole Blood ◽

Heart Surgery ◽

Ex Vivo ◽

Open Heart Surgery ◽

Clotting Time ◽

Blood Samples ◽

Alternative Approach ◽

Ecarin Clotting Time

SummaryThe use of recombinant ® hirudin as an anticoagulant in performing extracorporeal circulation systems including cardiopulmonary bypass (CPB) devices requires a specific and easy to handle monitoring system. The usefulness of the celite-induced activated clotting time (ACT) and the activated partial thromboplastin time (APTT) for r-hirudin monitoring has been tested on ex vivo blood samples obtained from eight patients treated with r-hirudin during open heart surgery. The very poor relationship between the prolongation of the ACT and APTT values and the concentration of r-hirudin as measured using a chromogenic factor Ila assay indicates that both assays are not suitable to monitor r-hirudin anticoagulation. As an alternative approach a whole blood clotting assay based on the prothrombin-activating snake venom ecarin has been tested. In vitro experiments using r-hirudin- spiked whole blood samples showed a linear relationship between the concentration of hirudin added and the prolongation of the clotting times up to a concentration of r-hirudin of 4.0 µg/ml. Interassay coefficients (CV) of variation between 2.1% and 5.4% demonstrate the accuracy of the ecarin clotting time (ECT) assay. Differences in the interindividual responsiveness to r-hirudin were analyzed on r-hirudin- spiked blood samples obtained from 50 healthy blood donors. CV- values between 1.8% and 6% measured at r-hirudin concentrations between 0.5 and 4 µg/ml indicate remarkably slight differences in r-hirudin responsiveness. ECT assay results of the ex vivo blood samples linearily correlate (r = 0.79) to the concentration of r-hirudin. Moreover, assay results were not influenced by treatment with aprotinin or heparin. These findings together with the short measuring time with less than 120 seconds warrant the whole blood ECT to be a suitable assay for monitoring of r-hirudin anticoagulation in cardiac surgery.

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