Successful Use of a Reduced Dose of Protamine After Cardiopulmonary Bypass

Guffin, Anita V.; Dunbar, Ronald W.; Kaplan, Joel A.; Bland, James W.

doi:10.1213/00000539-197601000-00025

Cited by 58 publications

(22 citation statements)

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“…In addition, platelet function has been shown to be inhib ited by heparin (53) possibly through factor VUI-associated platelet aggregation (54) or through von Willebrand factor-related mechanisms (55). Finally, it has been demonstrated that reduced doses of protamine for heparin neutralization after CPB can result in lower perioperative blood loss (23,31,56), and that this may be secondary to reduced complement levels (57) or reduced protamine-induced platelet inhibi tion (58). Since whole blood heparin concentration measurements more reliably reflect anti-Xa heparin concentration than do ACT meas urements in patients on CPB (16), protamine dosing schedules based on the former can facilitate administration of lower protamine doses relative to heparin doses.…”

Section: Discussionmentioning

confidence: 99%

More Effective Suppression of Hemostatic System Activation in Patients Undergoing Cardiac Surgery by Heparin Dosing Based on Heparin Blood Concentrations rather than ACT

et al. 1996

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SummaryThis study was designed to determine whether the maintenance of higher than usual patient-specific heparin concentrations during cardiopulmonary bypass (CPB) was associated with more effective suppression of hemostasis system activation.Thirty-one patients scheduled for repeat cardiac sugery or combined procedures (i.e., coronary revascularization + valve repair/replacement) were consented and enrolled in this study. All patients received porcine heparin and protamine and were randomly assigned to monitoring of anticoagulation by either celite ACT alone (Control, n = 16) or by kaolin ACT combined with on-site measurements of whole blood heparin concentration (Intervention, n = 15). Blood specimens collected before administration of heparin, before weaning from CPB and after administration of protamine were analyzed with a battery of coagulation assays.Patients in the intervention cohort received appreciably greater heparin doses than control patients, resulting in higher anti-Xa heparin levels at the end of CPB. Fibrinopeptide A and D-dimer levels were higher in the control group before discontinuation of CPB. Percent decrease during CPB were greater in the control group for factors V and VIII, fibrinogen and antithrombin III. Percent decrease in complement 3 was greater in the control group after protamine and bleeding times measured in the Intensive Care Unit were significantly more prolonged in this group.Maintenance of higher patient-specific heparin concentrations during CPB more effectively suppresses excessive hemostatic system activation than do standard heparin doses chosen based on measurement of ACT. These findings may explain, at least in part, the significant reduction in perioperative blood loss and blood product use when higher heparin concentrations are maintained.

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Section: Discussionmentioning

confidence: 99%

More Effective Suppression of Hemostatic System Activation in Patients Undergoing Cardiac Surgery by Heparin Dosing Based on Heparin Blood Concentrations rather than ACT

et al. 1996

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“…[2][3][4]16 Tranexamic acid is a synthetic antifibrinolytic drug that inhibits the lysine-binding site on plasmin and plasminogen. Plasmin not only facilitates fibrinolysis, but also inhibits thrombin-and collagen-induced platelet aggregation.…”

Section: Figurementioning

confidence: 99%

Preservation of collagen-induced whole blood platelet aggregation by tranexamic acid therapy in primary cardiac valve surgery

et al. 2000

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Haemostatic disorder is one of the most common complications following cardiac surgery with cardiopulmonary bypass (CPB). Tranexamic acid reduces blood loss and allogeneic blood transfusion requirement in cardiac surgery. It had been thought that tranexamic acid inhibited fibrinolysis alone following CPB. In the present study, the haemostatic effects of tranexamic acid (20 mg/kg body weight bolus after induction of anaesthesia followed by continuous infusion at 2 mg/kg/h), including fibrinolysis and platelet function, were investigated in 22 patients (tranexamic acid group n = 12; control group n = 10) undergoing primary cardiac valve surgery. Fibrinolysis following CPB was reduced significantly in the tranexamic acid group. Following protamine administration, the reduction of collagen-induced whole blood platelet aggregation was mitigated significantly in the tranexamic acid group compared with the control group (36% reduction in the tranexamic acid group vs 58% in the control group; p = 0.011), although platelet counts did not differ between the two groups. In conclusion, tranexamic acid not only inhibits fibrinolysis directly, but also may preserve platelet function following CPB.

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“…Alternatively, reductions in plasma coagulation factors or platelet function could have increased ACT independent of heparin or protamine effects. Because excessive protamine can increase both ACT and postoperative bleeding (15,20,21), it appears desirable to establish baseline ACT as accurately as possible. Diagnostic efforts could have then progressed toward a coagulation profile or thromboelastography.…”

Section: Discussionmentioning

confidence: 99%

Baseline Activated Coagulation Time Should Be Measured After Surgical Incision

Gravlee

Whitaker

Mark

et al. 1990

Anesthesia & Analgesia

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The activated coagulation time (ACT) is widely used to guide heparin and protamine dosing during cardiac surgery. A common protocol involves establishing a baseline ACT before administering heparin, then using this ACT as a target value for assessing the adequacy of heparin neutralization after cardiopulmonary bypass. Results vary in previous comparisons of baseline ACT to postprotamine ACT, with some showing postprotamine ACT significantly below baseline values. The present study examined ACTs at three possible baseline intervals in 68 patients at two institutions: (a) before anesthetic induction; (b) after anesthetic induction; and (c) after sternotomy. Baseline ACT decreased significantly with anesthesia and surgery. The poststernotomy baseline ACT best matched the postprotamine ACT. It appears likely that surgery induces a thromboplastic response that decreases ACT. Establishing baseline ACT before anesthetic induction would predispose to false diagnoses of adequate protamine neutralization after cardiopulmonary bypass, because ACT is relatively insensitive to low concentrations of unneutralized heparin. Baseline ACTs should therefore be measured after surgical incision.

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Successful Use of a Reduced Dose of Protamine After Cardiopulmonary Bypass

Cited by 58 publications

References 0 publications

More Effective Suppression of Hemostatic System Activation in Patients Undergoing Cardiac Surgery by Heparin Dosing Based on Heparin Blood Concentrations rather than ACT

More Effective Suppression of Hemostatic System Activation in Patients Undergoing Cardiac Surgery by Heparin Dosing Based on Heparin Blood Concentrations rather than ACT

Preservation of collagen-induced whole blood platelet aggregation by tranexamic acid therapy in primary cardiac valve surgery

Baseline Activated Coagulation Time Should Be Measured After Surgical Incision

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