Anticoagulant Monitoring and Neutralization during Open Heart Surgery???A Rapid Method for Measuring Heparin and Calculating Safe Reduced Protamine Doses

Umlas, Joel; Taff, R; Gauvin, Gregory; Swierk, Pamela

doi:10.1213/00000539-198312000-00010

Cited by 23 publications

(10 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Although we did not measure plasma concentrations of heparin that mobilized chemokines but not IFN-␥ in our patients, circulating levels of heparin have been measured at 24 to 70 g/mL before CPB and Ͻ1.5 g/mL after protamine administration. 19 It is possible that at concentrations used clinically, heparin may selectively modulate chemokine but not IFN-␥ activity. We also speculate that an excessive release of free chemokines when heparin activity is too rapidly reversed with ϩ memory T cells per cross section (x-sec) within the intima and whole vessel (A-C) and for the intima and total vessel areas (D).…”

Section: Discussionmentioning

confidence: 99%

Heparin Displaces Interferon-γ–Inducible Chemokines (IP-10, I-TAC, and Mig) Sequestered in the Vasculature and Inhibits the Transendothelial Migration and Arterial Recruitment of T Cells

et al. 2006

View full text Add to dashboard Cite

Background-Heparin, used clinically as an anticoagulant, also has antiinflammatory properties and has been described to inhibit interferon (IFN)-␥ responses in endothelial cells. We investigated the effects of heparin on the IFN-␥-inducible chemokines IP-10/CXCL10, I-TAC/CXCL11, and Mig/CXCL9, which play important roles in the vascular recruitment of IFN-␥-producing Th1 cells through interactions with their cognate receptor, CXCR3. Methods and Results-Patients undergoing coronary artery bypass grafting were studied because coronary atherosclerosis is recognized as a Th1-type inflammatory disease and the subjects required systemic heparinization. Plasma levels of IP-10, I-TAC, and Mig increased immediately after heparin administration and diminished promptly after heparin antagonism with protamine. These effects were independent of detectable circulating IFN-␥ or the IFN-␥ inducer interleukin-12. We confirmed previous reports that heparin inhibits the IFN-␥-dependent production of CXCR3 chemokine ligands using atherosclerotic coronary arteries in organ culture. In addition to prolonged treatment decreasing chemokine secretion, heparin rapidly displaced membrane-associated IP-10 from cultured endothelial cells that did not express CXCR3 and reduced the IP-10 -dependent transendothelial migration of T helper cells under conditions of venular shear stress. Finally, heparin administration to immunodeficient mouse hosts decreased both the recruitment and accumulation of memory T cells within allogeneic human coronary arteries. Conclusions-Besides

show abstract

Section: Discussionmentioning

confidence: 99%

Heparin Displaces Interferon-γ–Inducible Chemokines (IP-10, I-TAC, and Mig) Sequestered in the Vasculature and Inhibits the Transendothelial Migration and Arterial Recruitment of T Cells

et al. 2006

View full text Add to dashboard Cite

show abstract

“…Forman and Bayer 14 recommend this procedure for all forms of heparin treatment and Esposito et al 12 found the ACT "as the best available measurement for anticoagulation" during CPB. Others, 42,46,47 in contrast, advocate the use of quantitative heparin assays during CPB, not only to avoid occasional "false" ACT values due to changes in the clotting system, especially very high Factor VIII:C levels, but also monitor more precisely heparin during CPB and more accurately calculate the dose of protamine sulfate needed to neutralize heparin. Pro tamine in excess apparently can have considerable side effects on the cardiovascular system.…”

Section: Discussionmentioning

confidence: 99%

Hemostasis Changes During Cardiopulmonary Bypass Surgery

Mammen¹,

Koets²,

Washington³

et al. 1985

Semin Thromb Hemost

305

View full text Add to dashboard Cite

A number of hemostasis parameters were studied in a total of 63 patients undergoing cardiopulmonary bypass (CPB) for open heart surgery. In 33 patients fibrinogen, Factors II, V, VIII:C, X, XI, antithrombin, plasminogen, alpha 2-antiplasmin, and platelet counts were assayed before surgery, during maximal hypothermia, at the end of the bypass procedure, before and after protamine sulfate infusion, in the intensive care unit, and 48 hours postoperatively. All factors assayed decreased markedly when the patients were placed on the bypass machine, the drop fairly well paralleling the decrease in hematocrit. During bypass the factors remained low, although a slight tendency toward an increase was noted. Only platelet counts remained low with a decreasing trend until the end of bypass. In the intensive care unit a second decrease in fibrinogen, Factors II and V and antithrombin was noted. This drop was unrelated to four patients who experienced a greater blood loss during this time than the others. Forty-eight hours postoperatively, a marked increase could be found in all clotting factors and near normal levels were measured. Platelet counts remained low, however. The decrease in factors rarely dropped into a range where one would expect a compromised hemostasis (less than 30%). Although antithrombin levels decreased below 60%, no difficulties with heparinization were encountered. Several factors were assayed manually and by automated analyzer (Multistat III), and excellent correlations were found between both procedures. Also a good correlation was found between the activated whole blood clotting times and quantitative heparin assays. In 30 additional patients platelet function was studied before surgery, after thoracotomy, after heparin administration, after initiation of bypass, at maximal hypothermia, before and after protamine sulfate infusion, and 24 hours postoperatively. Platelet counts once again decreased as patients were placed on the CPB machine and remained low throughout the procedure. Mean platelet volumes were unchanged until protamine was given. At that time, a significant drop in mean platelet volume was recorded. Twenty-four hours postoperatively the volumes were normal again. Platelet aggregation studies were performed on a whole blood aggregometer using two concentrations of ADP, collagen, and ristocetin as aggregation inducers. A significant decrease in aggregability was seen when the patients were connected to the CPB apparatus.(ABSTRACT TRUNCATED AT 400 WORDS)

show abstract

“…100 Hardy et al found a large bias (mean Ϯ SD difference between values was 1.45 Ϯ 1.65 U/ml) between measurements derived from the automated protamine titration method and from anti-Xa measurements. 103 Although the Protopath system provides accurate plasma heparin concentration measurements, 104 its clinical usefulness is limited by the lack of clot-formation detection, the need for considerable technical expertise in assay standardization, the need to convert plasma heparin concentration values to whole blood equivalent values when determining protamine dose, and by equipment calibration and maintenance requirements. Although the exact relation between whole blood (automated protamine titration assay) and plasma (anti-Xa chromogenic) heparin levels needs further investigation, another recent study showed that patient-specific heparin concentrations can be maintained using the automated protamine titration assay.…”

Section: Heparin Concentration Assays Automated Protamine Titration Mmentioning

confidence: 99%

Anticoagulation Monitoring during Cardiac Surgery

et al. 1999

View full text Add to dashboard Cite

The literature does not consistently support the importance of anticoagulation monitoring techniques during CPB. This is best reflected by studies that have evaluated the impact of the ACT method on blood loss and transfusion outcomes. Inconsistent findings from studies that evaluated the impact of ACT monitoring may be related to either suboptimal study design (i.e., retrospective, unblinded, nonrandomized) or possibly the diagnostic inprecision of the ACT method used in these studies. There are a small number of well-controlled studies, some of which suggest that bleeding and transfusion outcomes can be improved by refining heparin monitoring techniques, either by sustaining better anticoagulation during CPB or by optimizing protamine doses (i.e., when empiric protocols result in excessive protamine doses). More well-controlled studies are needed to better define the importance of anticoagulation management during CPB.

show abstract

Anticoagulant Monitoring and Neutralization during Open Heart Surgery???A Rapid Method for Measuring Heparin and Calculating Safe Reduced Protamine Doses

Cited by 23 publications

References 0 publications

Heparin Displaces Interferon-γ–Inducible Chemokines (IP-10, I-TAC, and Mig) Sequestered in the Vasculature and Inhibits the Transendothelial Migration and Arterial Recruitment of T Cells

Heparin Displaces Interferon-γ–Inducible Chemokines (IP-10, I-TAC, and Mig) Sequestered in the Vasculature and Inhibits the Transendothelial Migration and Arterial Recruitment of T Cells

Hemostasis Changes During Cardiopulmonary Bypass Surgery

Anticoagulation Monitoring during Cardiac Surgery

Contact Info

Product

Resources

About