Predicting the pharmacodynamics of heparin: a clinical evaluation of the hepcon system 4

Gravlee, G.P.; Brauer, Stanley D.; Roy, Raymond C.; Howard, George; Kiger, Jeannie; Scott, Carmen; Royster, Roger L.; Pauca, Alfredo L.

doi:10.1016/s0888-6296(87)96676-2

Cited by 14 publications

(8 citation statements)

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“…Patients receiving a heparin overdosage may manifest a bleeding tendency; they require more protamine and are, therefore, at higher risk for the protamine-related adverse effects. Moreover, the anticoagulant effect of additional heparin may decrease above a certain dosage 18 but, most importantly, increasing the dose of heparin in patients with an AT III deficiency is often not effective and may further reduce the amount of AT III available at the end of the operation. Several studies have demonstrated that, during and after CPB, there is a strong decrease in circulating AT III levels, which can reach values of 40 ± 50% of the baseline at the end of the operation.…”

Section: Treatment Of the Different Patterns Of Hrmentioning

confidence: 99%

Different patterns of heparin resistance: therapeutic implications

et al. 2002

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Heparin resistance (HR) during cardiac operations is a common feature. Its aetiology often recognizes a decrease in circulating antithrombin III (AT III) due to a preoperative heparin treatment. Nevertheless, some papers highlighted the existence of HR in patients with normal values of AT III. This paper was designed in order to identify this subgroup of AT III-independent heparin-resistant patients. Five hundred consecutive patients scheduled for coronary revascularization with cardiopulmonary bypass were enrolled in this prospective trial. HR was identified in 104 (20.8%) patients. Thirty-six of them (7.2% of the total population) had a preoperative AT III activity > or = 100%, and were defined as AT III-independent heparin-resistant patients. This subgroup significantly differs from the AT III-dependent heparin-resistant group being affected by a less severe degree of HR and including less patients pretreated with heparin. Unlike the other heparin-resistant patients, these subjects do not respond to AT III supplementation aimed at reaching supranormal AT III activity values.

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Section: Treatment Of the Different Patterns Of Hrmentioning

confidence: 99%

Different patterns of heparin resistance: therapeutic implications

et al. 2002

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“…The ACT bioassay is influenced by many factors and the optimal level required is still unknown [ 2 ]. In order to improve heparin dosing regimen during CPB, a concept of estimating the individual heparin dose response has been developed [ 3 ], but the clinical results remain conflicting [ 4 ].…”

Section: Introductionmentioning

confidence: 99%

Heparin and Protamine Titration Does Not Improve Haemostasis after Cardiac Surgery: A Prospective Randomized Study

et al. 2015

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BackgroundBleeding complications are common in cardiac surgery. Perioperative handling of heparin and protamine may influence the haemostasis. We hypothesized that heparin and protamine dosing based on individual titration curves would improve haemostasis in comparison to standard dosing.Subjects and MethodsSixty patients scheduled for first time elective coronary artery bypass grafting or valve surgery were included in a prospective randomized study. The patients were randomized to heparin and protamine dosing with Hepcon HMS Plus device or to standard weight and activated clotting time (ACT) based dosing. Blood samples were collected before and 10 minutes, 2 hours and 4 hours after cardiopulmonary bypass. Primary endpoint was endogenous thrombin potential in plasma 2 hours after surgery as assessed by calibrated automated thrombography. Secondary endpoints included total heparin and protamine doses, whole blood clot formation (thromboelastometry) and post-operative bleeding volume and transfusions. Heparin effect was assessed by measuring anti-Xa activity.ResultsEndogenous thrombin potential and clot formation deteriorated in both groups after surgery without statistically significant intergroup difference. There were no significant differences between the groups in total heparin and protamine doses, heparin effect, or postoperative bleeding and transfusions at any time point. Significant inverse correlations between anti-Xa activity and endogenous thrombin potential were observed 10 min (r = -0.43, p = 0.001), 2 hours (r = -0.66, p<0.001) and 4 hours after surgery (r = -0.58, p<0.001).ConclusionIn conclusion, the results suggest that perioperative heparin and protamine dosing based on individual titration curves does not improve haemostasis after cardiac surgery. Postoperative thrombin generation capacity correlates to residual heparin effect.Trial Registration www.isrctn.com ISRCTN14201041.

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“…Platelet-rich plasma (20% of the patients' estimated plasma volume) was removed preheparinization by methods previously described (31). The average concentration of platelets in the product removed at our institution during this time period using this technique was (13,14) Platelet count (7,15,16) Antithrombin III deficiency (17)(18)(19)(20) IABP use (1,10) Autologous blood removal (21,21) Endocarditis (22) IABP ‫ס‬ intra-aortic balloon pump.…”

Section: Methodsmentioning

confidence: 97%

5-Year Incidence of Thrombocytosis and the Effect on Heparin Dose Response and Heparin Requirements

Gayoso

1999

J Extra Corpor Technol

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Thrombocytosis has been shown to be associated with heparin resistance. Contact activation of platelets results in release of Platelet Factor 4 from alpha granules present in the platelet cytoplasm. Platelet Factor 4 is a cationic substance that neutralizes heparin. This could result in inadequate heparinization during cardiopulmonary bypass (CPB). Inability to adequately anticoagulate patients with thrombocytosis could result in a poor clinical outcome. A retrospective review of pump records from 1991 to 1996 was used to assess the frequency of thrombocytosis, describe the demographic characteristics of patients with thrombocytosis, and determine the effects on patient heparin dose response (HDR) and additional heparin requirements. A platelet count of 400,000/mm3 was chosen as a cut-off for thrombocytosis. Of the 3281 patients undergoing CPB during this time period, a total of 571 patients were included in this review: 99 had high platelet counts. The over-all prevalence of thrombocytosis during this time period was 3.0%. Patients with thrombocytosis tended to be younger (p = .02), have lower preoperative HCT (p < .001), and weigh less (p < .001). These patients had lower post-heparin loading dose ACTs, lower HDR, required more additional heparin to reach an ACT of 480 sec before CPB, and required more heparin on CPB to maintain the ACT > 480 sec (p < .05). Multiple linear regression was performed and concluded that age, use of NTG and heparin drip preoperatively, and platelet count were significant predictors of the heparin dose response. Use of plasmapheresis to remove platelet-rich plasma (PRP) before CPB was performed in 22 patients, six of whom had high platelet counts. In these patients, removal of PRP resulted in no difference in the amount of additional heparin required pre-CPB to reach an ACT of 480 sec. (p = NS) Additional studies are needed to determine whether use of plasmapheresis is a cost-effective and clinically useful option in patients with thrombocytosis.

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Predicting the pharmacodynamics of heparin: a clinical evaluation of the hepcon system 4

Cited by 14 publications

References 50 publications

Different patterns of heparin resistance: therapeutic implications

Different patterns of heparin resistance: therapeutic implications

Heparin and Protamine Titration Does Not Improve Haemostasis after Cardiac Surgery: A Prospective Randomized Study

5-Year Incidence of Thrombocytosis and the Effect on Heparin Dose Response and Heparin Requirements

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