RESUMO
In unfractionated heparin (UFH) monitoring during extracorporeal circulation, the traditional measures of activated clotting time (ACT) or activated partial thromboplastin time (APTT) may diverge, confounding anticoagulant adjustments. We aimed to explore the factors explaining this discrepancy in children and young adults. This retrospective observational study, conducted at an urban regional tertiary hospital, included consecutive pediatric patients who received UFH during extracorporeal circulation (continuous kidney replacement therapy or extracorporeal membrane oxygenation) between April 2017 and March 2021. After patients whose ACT and APTT were not measured simultaneously or who were also taking other anticoagulants were excluded, we analyzed 94 samples from 23 patients. To explain the discrepancy between ACT and APTT, regression equations were created using a generalized linear model (family = gamma, link = logarithmic) with ACT as the response variable. Other explanatory variables included age, platelet count, and antithrombin. Compared to APTT alone as an explanatory variable, the Akaike information criterion and pseudo-coefficient of determination improved from 855 to 625 and from 0.01 to 0.42, respectively, when these explanatory variables were used. In conclusion, we identified several factors that may explain some of the discrepancy between ACT and APTT in the routinely measured tests. Evaluation of these factors may aid in appropriate adjustments in anticoagulation therapy.
Assuntos
Circulação Extracorpórea , Heparina , Humanos , Heparina/farmacologia , Heparina/uso terapêutico , Feminino , Masculino , Criança , Estudos Retrospectivos , Circulação Extracorpórea/métodos , Adolescente , Tempo de Tromboplastina Parcial/métodos , Pré-Escolar , Adulto Jovem , Adulto , Lactente , Anticoagulantes/uso terapêutico , Anticoagulantes/farmacologia , Coagulação Sanguínea/efeitos dos fármacos , Tempo de Coagulação do Sangue Total/métodosRESUMO
BACKGROUND: To find a new bedside method to monitor the anticoagulation effects of low-molecular-weight heparins (LMWHs) in patients with a high risk of venous thromboembolism (VTE). RESEARCH DESIGN AND METHODS: A total of 32 hospitalized patients (aged ≥60 years) who were at high risk of VTE were assigned to receive subcutaneous LMWH for 5 to 14 days. Plasma anti-factor Xa (anti-Xa) activity was conducted by a chromogenic method, and the glass bead-activated whole blood clotting time (gb-ACT) value was obtained by a Sonoclot Analyzer. RESULTS: A correlation between the gb-ACT values and the anti-Xa levels was suggested (R = 0.447, p = 0.002), and it was stronger in the older group aged 80 years above (R = 0.467, p = 0.008) and in the group of patients with an eGFR of 30 ~ 60 mL/min (R = 0.565, p = 0.005). The area under the curve (AUC) for gb-ACT by receiver operating characteristic (ROC) curve evaluation was 0.725 (p = 0.011), and the gb-ACT >282.5s provided a sensitivity of 60% and specificity of 74% for anti-Xa >0.800 IU/ml. CONCLUSIONS: The gb-ACT values detected by a Sonoclot Analyzer could act as a novel bedside method in the monitoring of LMWH anticoagulation.
Assuntos
Anticoagulantes , Monitoramento de Medicamentos , Inibidores do Fator Xa , Heparina de Baixo Peso Molecular , Tromboembolia Venosa , Humanos , Tromboembolia Venosa/prevenção & controle , Idoso , Anticoagulantes/administração & dosagem , Anticoagulantes/efeitos adversos , Feminino , Masculino , Idoso de 80 Anos ou mais , Pessoa de Meia-Idade , Heparina de Baixo Peso Molecular/administração & dosagem , Heparina de Baixo Peso Molecular/efeitos adversos , Monitoramento de Medicamentos/métodos , Inibidores do Fator Xa/administração & dosagem , Inibidores do Fator Xa/efeitos adversos , Fatores Etários , Tempo de Coagulação do Sangue TotalRESUMO
INTRODUCTION: The Thai National Guidelines for Hemostatic Laboratory Testing were established in 2018. The guidelines recommend that the 20-min whole blood clotting time (20WBCT) method be used to diagnose/monitor snake bites. The aim of this study was to survey members of the Thailand National External Quality Assessment Scheme (NEQAS) for Blood Coagulation to investigate the use of 20WBCT testing compared between the 2021 post-guideline and 2007 pre-guideline periods. METHODS: In July 2021, questionnaires were sent from the Faculty of Medicine Siriraj Hospital, Mahidol University to 521 Thailand NEQAS for Blood Coagulation member laboratories to survey their WBCT practices. Current WBCT practices were compared with pre-guideline WBCT practices, and chi-square test (x2) was used to test for differences between groups. RESULTS: Ninety-seven (18.6%) of 521 surveys were returned. Seventy-one laboratories (73.2%) reported knowing about 20WBCT from the Thai national guidelines. The reported average frequency of overall WBCT testing in 2021 was 12.4 times/month. The proportion of laboratories that reported using the 20WBCT test increased from 2.0% in 2007 to 46.4% in 2021 (p < 0.001), and the indications for performing WBCT were virtually unchanged from 2007 to 2021. The proportion of laboratories that reported having problems with WBCT testing decreased from 32.7% in 2007 to 16.5% in 2021. CONCLUSION: Despite our findings that almost three-quarters of respondent laboratories reported knowing about 20WBCT testing from the WBCT guidelines, and that WBCT-specific problems decreased significantly from 2007 to 2021, more work and training is needed to improve WBCT guideline dissemination, understanding, and adherence in Thailand.
Assuntos
Coagulação Sanguínea , Humanos , Tailândia , Tempo de Coagulação do Sangue Total/normas , Inquéritos e Questionários , Garantia da Qualidade dos Cuidados de Saúde , Guias de Prática Clínica como Assunto , Laboratórios Clínicos/normasRESUMO
INTRODUCTION: Endovascular left atrial appendage occlusion (LAAO) is associated with a high incidence of peri-procedure silent cerebral embolism (SCE), while the recommended activated clotting time (ACT) level by the expert consensus is lower than that in atrial fibrillation (AF) ablation. The aim of our study was to investigate whether raising the targeted ACT level during LAAO to the same level as AF ablation could decrease the incidence of SCE. METHODS: It was a prospective observational cohort study. Consecutive AF patients receiving LAAO between January 2021 and December 2022 were included and categorized into two groups based on the time of enrollment. Patients enrolled in 2021 (group 250) maintained a target ACT level of ≥250 s during LAAO procedure, while patients enrolled in 2022 (group 300) maintained the peri-procedure ACT ≥300 s. All patients underwent cerebral magnetic resonance imaging before and after the procedure. RESULTS: A total of 81 patients were included (38 in the group 250 and 43 in the group 300). After inverse probability of treatment weighting (IPTW), patients in the group 250 showed a significantly lower incidence of SCE than group 300 (IPTW p = 0.038). Only a stable high ACT pattern could decrease the risk of SCE. No significant differences were found between other ACT change patterns on the SCE incidence. CONCLUSION: Raising the peri-procedure ACT level to a stable 300 s could decrease the risk of the SCE without increasing the major bleeding events.
Assuntos
Anticoagulantes , Apêndice Atrial , Fibrilação Atrial , Embolia Intracraniana , Humanos , Masculino , Feminino , Fibrilação Atrial/complicações , Embolia Intracraniana/prevenção & controle , Embolia Intracraniana/etiologia , Embolia Intracraniana/diagnóstico por imagem , Estudos Prospectivos , Apêndice Atrial/cirurgia , Apêndice Atrial/diagnóstico por imagem , Idoso , Anticoagulantes/uso terapêutico , Anticoagulantes/administração & dosagem , Pessoa de Meia-Idade , Incidência , Tempo de Coagulação do Sangue Total , Imageamento por Ressonância Magnética , Procedimentos EndovascularesRESUMO
BACKGROUND: Radial access is preferred in patients with chronic coronary syndromes (CCSs) treated with ad hoc percutaneous coronary intervention (PCI). Antithrombotic and antiplatelet treatment before PCI may affect outcomes at vascular access sites. QuikClot Radial is a kaolin-based band that may shorten hemostasis time. Using point-of-care testing, we investigated the effect of antithrombotic and antiplatelet treatment on access-site complications. METHODS: This prospective observational study included consecutive patients with CCS on chronic aspirin therapy referred for ad hoc PCI. The activated clotting time (ACT), global thrombosis test and VerifyNow P2Y 12 test were done sequentially after unfractionated heparin (UFH) and clopidogrel administration. Patients were monitored for radial artery patency, bleeding and local hematoma until discharge. RESULTS: We enrolled 40 patients [mean age, 68.8â ±â 8.8 years; men, 30 (75%)] who received UFH (median dose, 8000â IU; interquartile range, 7000-9000â IU) and clopidogrel (600â mg). All radial arteries remained patent during follow-up. Local bleeding and hematomas were noted in 11 patients (27.5%) each. Patients with bleeding had lower mean platelet activity at 2â h [122.5â ±â 51 platelet reactivity units (PRU) vs. 158.7â ±â 43 PRU, P â =â 0.04] and higher ACT (216.9â ±â 40 s vs. 184.6â ±â 28 s, P = 0.006) than patients without bleeding. An ACT >196â s at 2â h predicted bleeding or hematoma (AUC, 0.72; 95% CI, 0.56-0.85, P = 0.008). CONCLUSION: Lower platelet activity and higher ACT after PCI were associated with higher bleeding risk at a vascular access site. Point-of-care testing of ACT after the procedure may help identify patients with CCS undergoing PCI who are at higher risk of access-site bleeding.
Assuntos
Clopidogrel , Intervenção Coronária Percutânea , Inibidores da Agregação Plaquetária , Artéria Radial , Humanos , Masculino , Intervenção Coronária Percutânea/efeitos adversos , Intervenção Coronária Percutânea/métodos , Feminino , Idoso , Estudos Prospectivos , Inibidores da Agregação Plaquetária/uso terapêutico , Inibidores da Agregação Plaquetária/efeitos adversos , Clopidogrel/efeitos adversos , Pessoa de Meia-Idade , Tempo de Coagulação do Sangue Total , Hemorragia/induzido quimicamente , Heparina/efeitos adversos , Ativação Plaquetária/efeitos dos fármacos , Doença Crônica , Hematoma/etiologia , Hematoma/sangue , Coagulação Sanguínea/efeitos dos fármacos , Anticoagulantes/efeitos adversos , Anticoagulantes/uso terapêutico , Aspirina/uso terapêutico , Aspirina/efeitos adversos , Valor Preditivo dos Testes , Grau de Desobstrução Vascular , Fatores de Risco , Testes ImediatosRESUMO
Ensuring adequate anticoagulation for patients requiring cardiac surgery and cardiopulmonary bypass (CPB) is important due to the adverse consequences of inadequate anticoagulation with respect to bleeding and thrombosis. When target anticoagulation is not achieved with typical doses, the term heparin resistance is routinely used despite the lack of uniform diagnostic criteria. Prior reports and guidance documents that define heparin resistance in patients requiring CPB and guidance documents remain variable based on the lack of standardized criteria. As a result, we conducted a review of clinical trials and reports to evaluate the various heparin resistance definitions employed in this clinical setting and to identify potential standards for future clinical trials and clinical management. In addition, we also aimed to characterize the differences in the reported incidence of heparin resistance in the adult cardiac surgical literature based on the variability of both target-activated clotting (ACT) values and unfractionated heparin doses. Our findings suggest that the most extensively reported ACT target for CPB is 480 seconds or higher. Although most publications define heparin resistance as a failure to achieve this target after a weight-based dose of either 400 U/kg or 500 U/kg of heparin, a standardized definition would be useful to guide future clinical trials and help improve clinical management. We propose the inability to obtain an ACT target for CPB of 480 seconds or more after 500 U/kg as a standardized definition for heparin resistance in this setting.
Assuntos
Procedimentos Cirúrgicos Cardíacos , Trombose , Adulto , Humanos , Heparina/efeitos adversos , Anticoagulantes/efeitos adversos , Tempo de Coagulação do Sangue Total , Coagulação Sanguínea , Procedimentos Cirúrgicos Cardíacos/efeitos adversos , Ponte Cardiopulmonar/efeitos adversos , Cuidados Críticos , Trombose/etiologia , Trombose/prevenção & controle , Trombose/tratamento farmacológico , ComunicaçãoRESUMO
ACT (Activated Clotting Time) is a point of care test (POCT) on whole blood, used to monitor the heparinization of patients in the operating room in cardiac surgery (ExtraCorporeal Circulation ECC) and in interventional cardiology (TAVI, AF ablation). The ACT is concerned both by the ISO 22 870 standard and French regulations regarding POCT. We performed an important work at the Bordeaux CHU on its accreditation, by rationalizing and making the park uniform (11 HemochronTM Signature Elite), standardizing the training and the habilitation of operators in medical units, introducing periodic quality controls, centralizing in the laboratory the management of the devices and reagents and by connecting it to the laboratory's computer system (Middleware, SIL et expert softwares). One year after, we have some positive feedbacks with only a few technical problems and with only few remarks raised during internal audits.
Assuntos
Procedimentos Cirúrgicos Cardíacos , Heparina , Humanos , Heparina/uso terapêutico , Testes Imediatos , Acreditação , Hospitais , Tempo de Coagulação do Sangue TotalRESUMO
BACKGROUND: Mechanical circulatory support devices, such as left ventricular assist devices, have recently been used in patients with heart failure as destination therapy but the formation of thrombus in blood pumps remains a critical problem. In this study, we propose a mechanical antithrombogenic method by impeller excitation using a magnetically levitated (Maglev) centrifugal pump. Previous studies have shown that one-directional excitation prevents thrombus; however, it is effective in only one direction. In this study, we aimed to obtain a better effect by vibrating it in a circular orbit to induce uniform changes in the shear-rate field entirely around the impeller. METHODS: The blood coagulation time was compared using porcine blood. (1) The flow rate was set to 1 L/min, and applied excitation was at a frequency of 280 Hz and amplitude of 3 µm. (2) Moreover, the effect was compared by varying the frequency, amplitude, and direction of the excitation. In this experiment, the flow rate was set to 0.3 L/min. RESULTS: (1) The thrombus formation time was 77 min without excitation and 133 min with excitation, which was 1.7 times longer. (2) The results showed no difference between (280 Hz, 3 µm) and (50 Hz, 16 µm) circular orbital excitations, and no directional difference, with thrombus formation of 2.5 times longer under all conditions than that without excitation. CONCLUSION: In the case of simple reciprocating excitation, the time was approximately 1.2 times longer. This indicated that the circular orbital excitation is more effective.
Assuntos
Coração Auxiliar , Trombose , Animais , Suínos , Centrifugação , Coração Auxiliar/efeitos adversos , Trombose/etiologia , Trombose/prevenção & controle , Desenho de Prótese , Tempo de Coagulação do Sangue Total , Desenho de EquipamentoRESUMO
INTRODUCTION: The Activated Clotting Time (ACT) is commonly used to manage anticoagulation during cardiac surgery. The aim of this study was to compare the older manually operated Hemochron® Response and the automated Hemochron® Signature Elite. METHODS: In this observational study the clinically relevant differences of both devices were investigated simultaneously, using duplicate measurements, in 29 patients who underwent a Coronary Artery Bypass Grafting (CABG) or Aortic Valve Replacement (AVR) in order to determine reliability, bias, and to detect which method has the lowest variation. Blood samples were obtained from the arterial line prior to surgery, after administration of 300 IU/kg heparin, 5 minutes after initiation of cardiopulmonary bypass and successively every 30 minutes, and after protamine administration. RESULTS: A total of 202 measurements were performed. Of these 10 measurements were out of range in the Response and 9 in the Elite. About 27 single unstable magnet errors were seen in the Response versus no measurement errors in the Elite. No statistically significant differences between the Response (p = 0.22, Wilcoxon rank) and Elite (p = 0.064) duplicates were observed. The Response values were consistently higher during heparinization than the Elite measurements (p = 0.002, repeated measurements) with an average positive bias of around 56 seconds during heparinization (Bland-Altman). Overall, the coefficient of variation (CoV) increased during heparinization. CONCLUSION: The Elite was more reliable, but the variation was higher for the Elite than the Response. The observed positive bias in the Response compared to the Elite could affect heparin administration during surgery making the two systems not interchangeable.
Assuntos
Anticoagulantes , Heparina , Humanos , Anticoagulantes/farmacologia , Anticoagulantes/uso terapêutico , Tempo de Coagulação do Sangue Total , Reprodutibilidade dos Testes , Testes de Coagulação Sanguínea , Heparina/uso terapêutico , Ponte CardiopulmonarRESUMO
OBJECTIVES: To determine the onset of heparin anticoagulation, using 2 different measures of activated clotting times (ACT), thromboelastography (TEG; R-time), and anti-Xa levels, after administering low- (100 U/kg) and high- (300 U/kg) dose intravenous (IV) heparin to patients undergoing transcatheter aortic valve replacement (TAVR) and cardiac surgery, respectively. DESIGN: Prospective study. SETTING: Single academic institution. PARTICIPANTS: Patients with normal baseline coagulation presenting for TAVR or cardiac valve surgery. INTERVENTIONS: Coagulation studies were performed at baseline, 30 seconds, 90 seconds, and 180 seconds after IV heparin administration. The tests included iSTAT (iACT) and Hemochron ACT (hACT), TEG R-Time, and anti-Xa levels. At the authors' institution, anti-Xa is the preferred measure of heparin anticoagulation when time permits. ACT, a rapid point- of-care test, is used to assess intraprocedural anticoagulation. MEASUREMENTS AND MAIN RESULTS: After both low- and high-dose heparin, there are peak increases in ACT and anti-Xa at 30 seconds, followed by a decline at 90 seconds and plateau at 180 seconds. The TEG R-time remained elevated (>80 minutes) throughout. For TAVR cases, all anti-Xa was >1.5 IU/mL, and was associated with an iACT >180 seconds and an hACT >200 seconds. For cardiac valve surgery cases, all anti-Xa was >2.4 and associated with an iACT >420 seconds and and hACT >340 seconds. Compared with hACT, iACTs were significantly lower at all time points after low-dose heparin, but not after high-dose heparin. CONCLUSIONS: In this pilot study, heparin anticoagulation was detected as early as 30 seconds after IV administration, based on ACT, anti-Xa levels, and TEG R-time.
Assuntos
Procedimentos Cirúrgicos Cardíacos , Cardiologia , Humanos , Projetos Piloto , Anticoagulantes , Estudos Prospectivos , Heparina , Tempo de Coagulação do Sangue TotalRESUMO
The use of heparin for anticoagulation has changed the face of cardiac surgery by allowing a bloodless and motionless surgical field throughout the introduction of cardiopulmonary bypass (CPB). However, heparin is a drug with complex pharmacologic properties that can cause significant interpatient differences in terms of responsiveness. Heparin resistance during CPB is a weighty issue due to the catastrophic consequences stemming from inadequate anticoagulation, and the treatment of it necessitates a rationalized stepwise approach due to the multifactorial contributions toward this entity. The widespread use of activated clotting time (ACT) as a measurement of anticoagulation during CPB is examined, as it may be a false indicator of heparin resistance. Heparin resistance also has been repeatedly reported in patients infected with COVID-19, which deserves further exploration in this pandemic era. This review aims to examine the variability in heparin potency, underlying mechanisms, and limitations of using ACT for monitoring, as well as provide a framework towards the current management of heparin resistance.
Assuntos
COVID-19 , Procedimentos Cirúrgicos Cardíacos , Adulto , Anticoagulantes/farmacologia , Anticoagulantes/uso terapêutico , Procedimentos Cirúrgicos Cardíacos/efeitos adversos , Ponte Cardiopulmonar/efeitos adversos , Heparina/farmacologia , Heparina/uso terapêutico , Humanos , Tempo de Coagulação do Sangue TotalRESUMO
Pediatric patients undergoing cardiopulmonary bypass (CPB) require adequate anticoagulation to combat hemostatic activation. Heparin is used to bind and catalyze antithrombin III (ATIII) that works to inhibit clot formation. To dose heparin, a weight-based (WB) or patient-specific concentration-based (PSCB) method can be used. The WB protocol calculates the dose based on the patients' weight and uses an activated clotting time (ACT) test to ensure anticoagulation. The ACT has limitations during CPB especially for pediatric patients who have immature hemostatic systems. The PSCB method predicts the patients' response to heparin by projecting a heparin dose-response (HDR) curve. Some investigators have found benefit to using the PSCB method but further investigation into how well the HDR predicts the heparin response is needed. A literature review was conducted for studies that looked at heparin management strategies in pediatric CPB patients between 1992 and 2020. Articles that focused on pediatric physiology, heparin management strategies, and anticoagulation were included. Articles older than 1990 were excluded. The literature review highlights that utilizing the PSCB approach more adequately anticoagulated patients. The WB protocol was found to have several flaws due to its reliance on the ACT, especially in infants. The results show that further investigation is needed to understand why there is benefit to using the PSCB approach. Observing the association between the HDR curve and subsequent heparin concentrations could determine how accurately it predicts the patients' response to heparin and why there is benefit to using this method.
Assuntos
Ponte Cardiopulmonar , Hemostáticos , Anticoagulantes/farmacologia , Anticoagulantes/uso terapêutico , Coagulação Sanguínea , Criança , Hemostáticos/farmacologia , Heparina/farmacologia , Heparina/uso terapêutico , Humanos , Lactente , Tempo de Coagulação do Sangue Total/métodosRESUMO
INTRODUCTION: Extracorporeal circulation (ECC) in cardiac surgery is performed under systemic heparinization. Adequacy of heparin therapy and anticoagulation during ECC is assessed by activated clotting time (ACT), although there are concerns regarding the reliability of this measure. The ACT can be affected by factors other than heparin anticoagulation. A novel factor that should be considered is the influence of a COVID-19 infection. More than half of the hospitalized COVID-19 patients develop coagulation abnormalities with dysregulated coagulation test results. Patients recently recovered from COVID-19 may still demonstrate some forms of coagulation disorder affecting the ACT. This case describes an inaccurate point-of-care ACT testing in a patient with previous COVID-19 infection undergoing cardiac surgery with ECC and the alternative coagulation testing performed. CASE PRESENTATION: A 77-years-old Caucasian male presented with symptomatic severe mitral valve regurgitation for which he underwent surgery. Medical history revealed a COVID-19 infection one month before surgery. Pre-operative hematological lab results were normal and baseline ACT during surgery was 100 s. To achieve an adequate ACT of > 400 s, multiple doses of heparin were needed and after administration of a triple dose (75,000 IE heparin in total) this adequate ACT was achieved. In the meanwhile we measured anti-Xa level and APTT, which were at adequate levels when ACT was still < 400 s. DISCUSSION: This case emphasizes the need of alternative methods for monitoring heparin therapy in case ACT does not respond adequately. Another point to highlight in this case is the poorly correlated relation between ACT and APTT and anti-Xa in light of the recent COVID-19 infection. Although studies have shown that COVID-19 infection can cause coagulopathy and altered hemostatic parameters, ACT has never been investigated in COVID-19 patient. Understanding the correlation between ACT, APTT and anti-Xa in COVID-19 patients is mandatory.
Assuntos
COVID-19 , Ponte Cardiopulmonar , Idoso , Anticoagulantes/uso terapêutico , Heparina/uso terapêutico , Heparina de Baixo Peso Molecular , Humanos , Masculino , Sistemas Automatizados de Assistência Junto ao Leito , Reprodutibilidade dos Testes , Tempo de Coagulação do Sangue TotalRESUMO
INTRODUCTION: The activated clotting time (ACT) is a useful marker of unfractionated heparin (UFH) activity during cardiopulmonary bypass (CPB) or cardiac catheterization. Emicizumab, recently approved for bleeding prevention in haemophilia A patients, acts like FVIII but does not need prior activation; it therefore shortens coagulation times in assays using intrinsic pathway activators and so is expected to shorten the ACT. AIM: To evaluated emicizumab's impact on heparin-induced ACT (Hemochron®) prolongation. METHODS: We measured the high-range (HR) ACT in citrated blood samples from healthy donors (HDs) (n = 9), CPB patients (n = 3) and emicizumab-treated patients (n = 5) after spiking with UFH and/or emicizumab. The low range (LR) ACT was also measured in spiked-samples from HDs and emicizumab-treated patients. RESULTS: In HDs, the median [interquartile range] baseline HR-ACTs were similar with and without emicizumab (129 [123-138] and 136 [115-141] s for 50 µg/ml, respectively); whatever the concentration of emicizumab (10 to 50 µg/ml), increasing the UFH concentration (1-5 UI/ml) prolonged the HR-ACT. In blood from patients undergoing CPB, the HR-ACT prolongation observed during this procedure was not masked by emicizumab at any concentration. Likewise, the addition of increasing concentrations of UFH to blood from emicizumab-treated patients induced a concentration-dependent prolongation of HR-ACT. Baseline LR-ACT were prolonged in emicizumab-treated patients but as for HR-ACT, emicizumab does not prevent heparin-induced prolongation of LR-ACT. CONCLUSION: Emicizumab does not interfere with UFH-induced ACT prolongation. The hemochron® ACT can be used to monitor UFH in patients receiving emicizumab during CPB or cardiac catheterization.
Assuntos
Anticorpos Biespecíficos , Heparina , Anticorpos Biespecíficos/farmacologia , Anticorpos Biespecíficos/uso terapêutico , Anticorpos Monoclonais Humanizados/farmacologia , Anticorpos Monoclonais Humanizados/uso terapêutico , Heparina/farmacologia , Heparina/uso terapêutico , Humanos , Tempo de Coagulação do Sangue TotalRESUMO
BACKGROUND AND OBJECTIVE: Activated clotting time (ACT) is a point-of-care test used to monitor the effect of unfractionated heparin (UFH) during cardiopulmonary bypass (CPB). This test sometimes returns aberrant values, which can lead to the administration of an inappropriate dosing regimen. The development of a population-robust K-PD model of UFH could allow the individualisation and automation of UFH therapy during CPB. METHODS: We conducted a prospective observational study to collect ACT measurements from patients undergoing surgery using CPB. The ACT data were split into a development and validation cohort. The development cohort was used to estimate a standard and robust population K-PD model characterised by a residual error following a normal distribution and student's t-distribution. The ACT prediction performance using Bayesian estimates of individual K-PD parameters was evaluated by comparing predicted versus observed ACTs. Using estimates of the robust K-PD model, a Bayesian individualisation strategy to automate UFH administration was proposed and evaluated using Monte Carlo simulations. RESULTS: A total of 295 patients were included in the study, and 1561 ACTs were collected. In patients without outlier values, Bayesian estimates (based on four ACT measurements) from both standard and robust K-PD models had similar performances, with a median prediction bias close to 0 s. In patients with outlier measurements, the use of the robust K-PD model greatly improved the prediction bias and root-mean-square error (RMSE), with a mean prediction bias of 3.25 s, IQR = [-19.9; 46.03] versus -86 s IQR = [-135.7; -63.8] for the standard model. Monte Carlo simulations showed that the robust Bayesian individualisation strategy allowed the ACT to be maintained above the target using only two to three ACT measurements. CONCLUSIONS: The use of a robust K-PD model reduced prediction bias and RMSE in patients with outlier ACT measurements. The Bayesian individualisation strategy using robust estimates of individual parameters may help automate UFH dosing regimens. Proper clinical validation is warranted before its use in daily clinical practice.
Assuntos
Ponte Cardiopulmonar , Heparina , Anticoagulantes , Teorema de Bayes , Humanos , Tempo de Coagulação do Sangue TotalRESUMO
PURPOSE: High-dose heparin has been suggested to reduce consumption coagulopathy. MATERIALS AND METHODS: In a randomized, blinded, prospective trial of patients undergoing elective, complex cardiac surgery with cardiopulmonary bypass, patients were randomized to one of three groups: 1) high-dose heparin (HH) receiving an initial heparin dose of 450 u/kg, 2) heparin concentration monitoring (HC) with Hepcon Hemostasis Management System (HMS; Medtronic, Minneapolis, MN, USA) monitoring, or 3) a control group (C) receiving a standard heparin dose of 300 u/kg. Primary outcome measures were blood loss and transfusion requirements. RESULTS: There were 269 patients block randomized based on primary versus redo sternotomy to one of the three groups from August 2001 to August 2003. There was no difference in operative bleeding between the groups. Chest tube drainage did not differ between treatment groups at 8 hours (median [25th percentile, 75th percentile] for control group was 321 [211, 490] compared to 340 [210, 443] and 327 [250, 545], p = 0.998 and p = 0.540, for HH and HC treatment groups, respectively). The percentage of patients receiving transfusion was not different among the groups. CONCLUSION: Higher heparin dosing accomplished by either activated clot time or HC monitoring did not reduce 24-hour intensive care unit blood loss or transfusion requirements.
Assuntos
Procedimentos Cirúrgicos Cardíacos , Heparina , Anticoagulantes , Procedimentos Cirúrgicos Cardíacos/efeitos adversos , Ponte Cardiopulmonar/efeitos adversos , Heparina/efeitos adversos , Humanos , Preparações de Plantas , Estudos Prospectivos , Resultado do Tratamento , Tempo de Coagulação do Sangue TotalRESUMO
BACKGROUND: Sheep are a primary model of mechanical circulatory support (MCS) with heparin anticoagulation therapy frequently being monitored by activated clotting time (ACT) due to ease and cost. In patients undergoing long-term heparin therapy, other anticoagulation monitoring strategies, such as activated partial thromboplastin time (aPTT), have proven to be more reliable indicators for the adequacy of anticoagulation, frequently determined by heparin concentration. As there is a paucity of similar studies in sheep, we sought to investigate the correlation between heparin concentration and ACT and aPTT using whole sheep blood in an ex vivo model. METHODS: Fresh whole blood was serially drawn from an adult female Dorset-hybrid sheep and aliquots were placed into tubes containing heparin saline solutions with concentrations ranging from 0 to 7.81 U heparin per mL of whole blood. ACT and aPTT values were measured on each of the samples. The experiment was performed four times with the same animal. A simple linear regression was performed to determine correlation, and subgroup analysis was performed on low versus high heparin concentrations typically seen in human patients on long-term MCS, such as extracorporeal membrane oxygenation (ECMO), versus cardiopulmonary bypass, respectively. RESULTS: aPTT measurements versus the heparin concentration had an R2 = 0.7295. ACT measurements versus the heparin concentration had a R2 = 0.4628. aPTT measurements versus the ACT measurements had a R2 = 0.2974. The strength of the correlation between aPTT and heparin concentration increased at low heparin concentrations (R2 = 0.8392). CONCLUSION: aPTT had a more reliable correlation to heparin concentration and thus anticoagulation level than ACT. This was particularly true at lower heparin concentrations, similar to ranges seen for patients on ECMO. The correlation between aPTT and ACT values was poor. Further in vivo studies should be performed to confirm our results.
Assuntos
Anticoagulantes/administração & dosagem , Heparina/administração & dosagem , Tempo de Tromboplastina Parcial , Tempo de Coagulação do Sangue Total , Animais , Relação Dose-Resposta a Droga , Modelos Lineares , Modelos Animais , OvinosRESUMO
BACKGROUND: Cardiac surgery with extracorporeal circulation (ECC) requires the administration of anticoagulant drugs to maintain ACT ranges 400-600 seconds, which requires exhaustive coagulation monitoring for which various point-of-care devices are available. However, there is variability between them, so we aimed to compare the values in ACT measurement. METHODS: Simultaneous ACT measurements were performed with the Hemochron Response®, Hemostasis Management System Plus® (HMS Plus®) and Hemochron Signature® systems. RESULTS: A total of 255 simultaneous measurements were taken, the mean and standard deviation (SD) of each device were: Hemochron Signature® 361.1 seconds (SD: 156.9), HMS Plus® 412.8 seconds (SD: 180.9) and Hemochron Response® 422.8 seconds (SD: 187.9), being these differences statistically significant (Fridman's test p < 0.01). For comparisons the Bland-Altman method was used, resulting the Hemochron Response® has 61.7 seconds higher mean values than the Hemochron Signature®, the Hemochron Response® 10 seconds higher than the HMS Plus® and the HMS Plus® 51.7 seconds higher than the Hemochron Signature®. CONCLUSION: The differences found in comparisons are considered to be clinically relevant, which is why it is considered important to make the variability of the different monitoring systems known and to take them into account for optimal control of this parameter and its clinical repercussions.
Assuntos
Procedimentos Cirúrgicos Cardíacos , Sistemas Automatizados de Assistência Junto ao Leito , Anticoagulantes , Testes de Coagulação Sanguínea , Heparina , Humanos , Tempo de Coagulação do Sangue TotalRESUMO
Coagulation factor XII (FXII) is a plasma serine protease that belongs to the contact activation complex responsible for initiating the intrinsic coagulation pathway. FXII deficiency is a rare congenital disorder that is not associated with an increased tendency for bleeding. However, as contact activation is impaired in FXII deficiency, both the celite- and kaolin-initiated activated clotting time (ACT) measurements are prolonged markedly, which poses a challenge for anticoagulation monitoring in patients undergoing cardiac surgery. The authors successfully have used the standard Hemochron Jr. ACT+ test, which is activated by silica and phospholipid in addition to kaolin, to monitor anticoagulation for cardiopulmonary bypass in two patients with severe FXII deficiency. The ACT+ test showed low baseline values, increased adequately in response to heparin, and decreased to baseline after protamine. Importantly, there was no abnormal intra- or postoperative bleeding nor any thrombotic complications. Furthermore, in vitro dose-response ACT+ testing of FXII-deficient blood with increasing heparin concentrations supports the use of ACT+ in FXII deficiency.
Assuntos
Deficiência do Fator XII , Heparina , Anticoagulantes , Ponte Cardiopulmonar , Deficiência do Fator XII/complicações , Deficiência do Fator XII/diagnóstico , Deficiência do Fator XII/cirurgia , Humanos , Caulim , Sistemas Automatizados de Assistência Junto ao Leito , Tempo de Coagulação do Sangue TotalRESUMO
BACKGROUND: Leadless pacemaker was a promising innovation than traditional transvenous pacemaker, the procedural complications were prone to be bleeding-related. However, very few reports also concerned about the thrombus formation during the procedure. CASE PRESENTATION: A hemodialysis patient with diabetic gangrene of right foot suffered from catheter-related thrombosis during leadless pacing, resulting in failure of recapture the pacemaker. A low activated clotting time (ACT) level of 104 s confirmed the insufficiency of anticoagulation. Finally, the whole delivery catheter had to be removed from the delivery sheath, another new pacemaker system was applied and successfully implanted after adjusting the ACT level to 248 s. CONCLUSION: Catheter-related thrombosis could be a large obstacle for leadless pacemaker implantation. In addition to routine anticoagulation, ACT monitoring might be necessary during the procedure.