In vitro and in vivo effects of hemodilution on kaolin-based activated clotting time predicted heparin requirement using a heparin dose–response technique

2016 ◽  
Vol 30 (6) ◽  
pp. 923-928 ◽  
Author(s):  
Junko Ichikawa ◽  
Satoshi Hagihira ◽  
Testu Mori ◽  
Mitsuharu Kodaka ◽  
Keiko Nishiyama ◽  
...  
Keyword(s):  
Dose Response ◽  
Clotting Time ◽  
Heparin Dose ◽  
Activated Clotting Time ◽  
In Vivo Effects

Factors associated with errors in the heparin dose response test: recommendations to improve individualized heparin management in cardiopulmonary bypass

Perfusion ◽  
2020 ◽  
pp. 026765912095297
Author(s):  
Min-Ho Lee ◽  
William Riley
Keyword(s):  
Cardiopulmonary Bypass ◽  
Dose Response ◽  
Clotting Time ◽  
Critical Aspect ◽  
Heparin Dose ◽  
Factors Associated ◽  
Heparin Concentration ◽  
Activated Clotting Time

Background: A critical aspect of cardiopulmonary bypass (CPB) is to achieve full anticoagulation to prevent thrombosis and consumptive coagulation without using excessive amount of heparin. This can be achieved with heparin dose response (HDR) test in vitro to calculate an individualized heparin bolus to reach a target activated clotting time (ACT) and heparin concentration. However, we often observe that the measured ACT (mACT) with the calculated heparin bolus gives significant errors, both positive (mACT is higher than expected) and negative (mACT is lower), from expected ACT (eACT). Methods: We performed a retrospective study of 250 patients who underwent cardiac surgery to attain an error distribution of the mACT from eACT with calculated heparin bolus. In addition, it is aimed to identify possible patterns of baseline ACT (bACT), calculated heparin concentration (CHC) and HDR slope that are associated with the significant positive and negative errors. Results: We found that individualized heparin bolus by HDR test is consistently underestimated while it gave a significant number of positive and negative errors. Further analysis indicates that significant negative errors correlate with high bACT and slope and low CHC while significant positive errors with low bACT and slope and high CHC. Conclusion: The mACT can be substantially different from eACT. The accuracy of the HDR test appears to be dependent upon bACT, slope, and CHC. Based on our analysis, we provide several recommendations and a flow chart to improve the quality of individualized heparin management on CPB.

Effect of in vivo Administration of FeibaR on Clotting Tests: Dose-Response Relationship

1979 ◽  
Author(s):  
Chr. Nowotny ◽  
K. Lechner ◽  
H. Niessner ◽  
E. Thaler
Keyword(s):  
Dose Response ◽  
Dose Range ◽  
Inverse Correlation ◽  
In Vitro Test ◽  
Clotting Time ◽  
Vitro Test ◽  
R Value ◽  
Dose Dependent

FEIBA causes in vitro a concentration-dependent shortening of APTT of hemophilic plasma containing antibody to factor VIII. Since the potency of preparation is based on this in vitro test, it was of interest to examine whether a dose-dependent shortening of APTT and clotting time is also observed under in vivo conditions, APTT, whole blood glass clotting time and reaction time (=R value of thrombelastogramm) were determined before and 30 to 60 min. after 91 infusions of FE IBA (dose range 6 - 100 U/kg) to 10 hemophiliacs with antibody. Although there was a considerable scatter, a significant inverse correlation between the dose of FE IBA and postinfusion APTT and R-value was observedThe dose response curve was, however, rather flat. No significant correlation existed between FE IBA dose and glass clotting time. The effect of FE IBA on the APTT was not dependent on the antibody level, both, in vitro and in vivo. There was only a slight variant ot the effect among different patients, but a marked variation among different lots ot tne preparation, FE IBA seems to have a weak clinical hemostatic effect. A clear relationship between dose and clinical effect could not be established but it appears that doses higher than 50 U/kg are not more effective than smaller doses.

Reliability of the Heparin Management Test for Monitoring High Levels of Unfractionated Heparin

2000 ◽  
Vol 92 (6) ◽  
pp. 1594-1602 ◽  
Author(s):  
Fritz Mertzlufft ◽  
Andreas Koster ◽  
Roland Hansen ◽  
Anne Risch ◽  
Herrmann Kuppe ◽  
...  
Keyword(s):  
Cardiopulmonary Bypass ◽  
Storage Time ◽  
Coagulation Factors ◽  
Clotting Time ◽  
Activated Clotting Time ◽  
Group I ◽  
Group Ii ◽  
And Storage

Background The authors assessed the heparin management test in vitro in volunteers and in vivo during cardiopulmonary bypass. Methods In vitro, the heparin management test was analyzed for heparin levels between 0 and 6 IU/ml using variations in hematocrit, platelets, procoagulants, and storage time. The in vivostudies consisted of two groups: In group I (cardiopulmonary bypass </= 90 min, n = 40), anticoagulation was performed according to the activated clotting time (with or without aprotinin); in group II (cardiopulmonary bypass >/= 180 min, with aprotinin) included use (n = 10) and nonuse of coumadin (n = 10) and anticoagulation according to the automated heparin dose-response assay. Tests were performed in duplicate (whole blood, two heparin management test analyzers) and compared with anti-Xa activity (plasma). Results In vitro, the results of the heparin management test (n = 1,070) correlated well with heparin concentration (r2 = 0.98). Dilution and storage time did not affect the heparin management test; a hematocrit of 60% and reduced procoagulants (10%) prolonged clotting time. In vivo, the correlation (heparin management test vs. anti-Xa) was strong in group I (r2 = 0.97 [with aprotinin] and 0.96 [without aprotinin]; n = 960) and group II without coumadin (r2 = 0.89, n = 516). In group II with coumadin, the overall correlation was r2 = 0.87 and 0.79 (n = 484), although the range varied widely (0.57-0.94, between-analyzer differences 0-47%). Conclusions The results of the heparin management test were influenced by hematocrit, plasma coagulation factors, and the heparin level, but not by use of aprotinin. The heparin management test provided reliable values in vitro in group I, and in group II without coumadin but was less reliable in group II with coumadin.

RELEASE OF THYROTROPHIN IN VIVO AND IN VITRO BY SYNTHETIC NEUROHYPOPHYSIAL HORMONES

1964 ◽  
Vol 42 (1) ◽  
pp. 75-83 ◽  
Author(s):  
Frank S. LaBella
Keyword(s):  
Dose Response ◽  
In Vitro Release ◽  
Optimal Level ◽  
Response Curves ◽  
Low Concentrations ◽  
Pituitary Glands ◽  
In Vivo Effects ◽  
Synthetic Oxytocin

The influence of synthetic oxytocin and synthetic lysine-8-vasopressin on the release of thyrotrophin (TSH) from slices of the "basophilic" zone of bovine anterior pituitary glands was determined. Up to 10-fold stimulation of TSH release occurred in the presence of the peptide hormones at low concentrations (approximately 10−11 to 10−9 M). Concentrations greater than 10−9 M were less stimulatory, ineffective, or inhibitory. In general, vasopressin stimulated at lower concentrations than did oxytocin. The dose–response curve of oxytocin began to descend at lower concentrations than did that of vasopressin.Stimulation of I131 discharge from the thyroids of propylthiouracil (PTU)-treated, day-old chicks was produced by the intraperitoneal injection of as little as 4 ng vasopressin or 25 ng oxytocin. As the injected dose of either peptide was increased beyond an optimal level, there was less enhancement of I131 discharge, and, with further increases, inhibition. The decreasing response began with lower doses of oxytocin than of vasopressin. The similarities of the dose–response curves of thyroid I131 discharge and of in vitro release of TSH indicate that the in vivo effects of injected neurohypophysial peptides are mediated through the release of endogenous TSH.

Experimental study on the hemostatic effect of cyanoacrylate intended for catheter securement

2018 ◽  
Vol 20 (1) ◽  
pp. 79-86 ◽  
Author(s):  
Sheng Zhang ◽  
Amanda R Guido ◽  
Richard G Jones ◽  
Benjamin J Curry ◽  
Angela S Burke ◽  
...  
Keyword(s):  
Whole Blood ◽  
Blood Platelet ◽  
Clotting Time ◽  
Intravenous Catheter ◽  
Hemostatic Effect ◽  
Activated Clotting Time ◽  
In Vivo Testing ◽  
Bleeding Score

Purpose: The use of cyanoacrylate for intravenous catheter securement is of interest to clinicians and patients, because of the superior adhesive strength and hemostatic effect of cyanoacrylate compared to current securement devices. The purpose of this study is to use novel in vitro and in vivo testing methods to analyze the hemostatic effect of a catheter securement cyanoacrylate (cyanoacrylate). Methods: An unprecedented in vitro method was performed to determine the effects of a cyanoacrylate on a customized modified activated clotting time assay and blood flow inhibition assay by exposing blood or plasma to either one or three drops of cyanoacrylate. For the in vivo testing, full-thickness incisions were made on swine, and the bleeding was scored prior to treatment and at 3, 6, 9, and 12 min after treatment. Results: The cyanoacrylate rapidly achieved hemostasis in the presence of anticoagulated whole blood, platelet-poor plasma, and non-anticoagulated whole blood, in vitro. The cyanoacrylate achieved hemostasis 12-fold faster than thromboplastin in the modified activated clotting time assay. The cyanoacrylate does not alter normal blood clotting, as measured by prothrombin time. In vivo, the bleeding score of cyanoacrylate prior to treatment and at 3, 6, 9, and 12 min after treatment were 2.3 ± 1.0, 0.3 ± 0.5, 0.2 ± 0.5, 0.2 ± 0.4, and 0.2 ± 0.4, respectively. Conclusion: This study indicates that cyanoacrylate demonstrates a potent mechanical hemostatic effect and cyanoacrylate in the presence of anticoagulated whole blood has an activated clotting time that is 12 times quicker than thromboplastin. The cyanoacrylate was found to be significantly equivalent to two known hemostatic agents, in vivo.

COMPARISON OF HEPARIN DOSE RESPONSE TO ACTIVATED CLOTTING TIME IN INFANTS AND CHILDREN FOR CARDIAC SURGERY

1998 ◽  
Vol 86 (Supplement) ◽  
pp. 73SCA
Author(s):  
EB Mossad ◽  
K Marchant ◽  
PM Bokesch ◽  
JJ Niezgoda ◽  
RBB Mee ◽  
...  
Keyword(s):  
Cardiac Surgery ◽  
Dose Response ◽  
Infants And Children ◽  
Clotting Time ◽  
Heparin Dose ◽  
Activated Clotting Time ◽  
In Infants And Children

Comparison of the Anticoagulant and Antithrombotic Effects of Synthetic Thrombin and Factor Xa Inhibitors

1990 ◽  
Vol 63 (02) ◽  
pp. 220-223 ◽  
Author(s):  
J Hauptmann ◽  
B Kaiser ◽  
G Nowak ◽  
J Stürzebecher ◽  
F Markwardt
Keyword(s):  
Factor Xa ◽  
Thrombin Inhibitors ◽  
Factor Xa Inhibitors ◽  
Venous Stasis ◽  
Clotting Time ◽  
Thrombosis Model ◽  
Activity Factor ◽  
Antithrombotic Effects

SummaryThe anticoagulant effect of selected synthetic inhibitors of thrombin and factor Xa was studied in vitro in commonly used clotting assays. The concentrations of the compounds doubling the clotting time in the various assays were mainly dependent on their thrombin inhibitory activity. Factor Xa inhibitors were somewhat more effective in prolonging the prothrombin time compared to the activated partial thromboplastin time, whereas the opposite was true of thrombin inhibitors.In vivo, in a venous stasis thrombosis model and a thromboplastin-induced microthrombosis model in rats the thrombin inhibitors were effective antithrombotically whereas factor Xa inhibitors of numerically similar IQ value for the respective enzyme were not effective at equimolar dosageThe results are discussed in the light of the different prelequisiles and conditions for inhibition of thrombin and factor Xa in the course of blood clotting.

Pharmacology of 5-HT1A Receptors: Critical Aspects

CNS Spectrums ◽  
1998 ◽  
Vol 3 (10) ◽  
pp. 17-38 ◽  
Author(s):  
Franco Borsini
Keyword(s):  
Receptor Subtypes ◽  
Laboratory Conditions ◽  
In Vivo Effects ◽  
Critical Aspects

AbstractMyriad difficulties exist in analyzing the pharmacology of the serotonin 1A (5-HT1A) receptor. The receptor may demonstrate a different activity depending on the tissue or species used for analysis, the agent used, laboratory conditions, and differences between in vitro and in vivo effects of compounds. Affinity for 5-HT receptors also varies widely, presenting difficulties in drawing definitive conclusions on affinity values for various compounds. At least two possibilities exist to explain the diversity of pharmacology of 5-HT receptors. First, it is possible that different 5-HT1A receptor subtypes exist. Second, the 5-HT1A receptors may play a far more complex role than previously believed.

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