The Experts below are selected from a list of 312 Experts worldwide ranked by ideXlab platform
Liza M. Weavind - One of the best experts on this subject based on the ideXlab platform.
-
Perioperative Thromboelastography and sonoclot analysis in morbidly obese patients
Canadian Journal of Anaesthesia, 1997Co-Authors: Evan G. Pivalizza, Penelope J. Pivalizza, Liza M. WeavindAbstract:Purpose To investigate perioperative coagulation in morbidly obese (MO) patients with the Thromboelastograph (TEG) and Sonoclot analyzer. Methods Twenty-six consecutive morbidly obese and 26 consecutive lean patients presenting for elective surgery were enrolled in this prospective, observational study. Blood was sampled for TEG and Sonoclot analysis immediately after anaesthetic induction and at the end of surgery in the MO group, and immediately after anaesthetic induction in the lean group. The R and K times, alpha angle, maximum amplitude and percentage fibrinoiysis at 30 and 60 min were recorded from the TEG. The Sonoclot ACT, initial clot rate, peak amplitude and time to peak amplitude were recorded from the Sonoclot. Results The TEG in the MO group demonstrated decreased R and K times (8.6 ± 4.8 vs 11.7 ± 3.9 mm, and 2.8 ± 1.2 vs 3.5 ± 0.9 mm respectively (P < 0.05)), and increased alpha angle (73.7 ± 6.0 vs 66.7 ± 6.0°, P < 0.05) and maximum amplitude (72.0 ± 5.4 vs 67.9 ± 4.4 mm, P < 0.05), without change in fibrinolysis. Sonoclot variables in the MO group included increased clot rate (37.5 ± 11.5 vs 23.9 ± 7.7%, P < 0.05) and decreased time to peak impedance (11.7 ± 5.0 vs 17.5 ± 7.2 min, P < 0.05), without change in Sonoclot ACT or peak signature impedance. Conclusion The MO group demonstrated accelerated fibrin formation, fibrinogen-platelet interaction, and platelet function compared with lean controls but no difference in fibrinolysis. Viscoelastic measures of coagulation may be useful in MO patients, who are at increased risk of thromboembolic events. Objectif Examiner le bilan hémostatique de patients pathologiquement obèses par thromboélastographie (TÉG) et analyse Sonoclot. Méthodes Consécutivement, 26 sujets obèses pathologiques (OP) et 26 sujets maigres programmés pour une chirurgie élective ont participé à cette étude prospective et observationnelle. Chez les obèses, du sang a été prélevé pour l’analyse par TÉG et par Sonoclot immédiatement après l’induction de l’anesthésie et à la fin de la chirurgie et, chez les sujets maigres, immédiatement après l’induction. Les temps R et K, l’angle alpha, l’amplitude maximale et le pourcentage de fibnnolyse à 30 et 60 min ont été enregistrés par TÉG. L’ACT la vitesse initiate de formation du caillot, l’amplitude maximale et le temps d’amplitude maximale ont été enregistrés au Sonoclot. Résultats Dans le groupe OP, la TÉG a révélé une baisse des temps R et K (respectivement 8,6 ± 4,8 vs 11,7 ±3,9 mm et 2,8 ± 1,2 vs 3.5 ± 0,9 mm, P < 0,05) et une augmentation de l’angle alpha (73,7 ± 6,0 vs 66,7 ± 6,0°, P < 0,05) et de l’amplitude maximale (72,0 ± 5,4 vs 67,9 ± 4,4 mm, P < 0,05) sans changement fibrinolytique. Au Sonoclot, dans le groupe OP, on observait une augmentation de la vitesse de formation du caillot (37,5 ± 11,5 vs 23,9 ± 7,7%, P < 0,05) et une diminution du temps d’impédance maximale (11,7 ± 0,5 vs 17,5 ± 7,2 min, P < 0,05) sans changement à l’ACT Sonoclot ou à l’impédance maximaie de signature. Conclusion Dans groupe OP, la formation de fibrine, l’interaction fibrinogène-plaquettes et la fonction plaquettaire sont accélérées comparativement aux contrôles maigres alors que la fibrinolyse est identique. Les mesures viscoélastiques de la coagulation peuvent être utiles chez les obèses pathologiques qui sont à risque d’accidents thromboemboliques.
-
Perioperative Thromboelastography and sonoclot analysis in morbidly obese patients
Canadian journal of anaesthesia = Journal canadien d'anesthesie, 1997Co-Authors: Evan G. Pivalizza, Penelope J. Pivalizza, Liza M. WeavindAbstract:Purpose To investigate perioperative coagulation in morbidly obese (MO) patients with the Thromboelastograph (TEG) and Sonoclot analyzer.
John Roy - One of the best experts on this subject based on the ideXlab platform.
-
Pediatric Thromboelastograph 6s and Laboratory Coagulation Reference Values.
Archives of pathology & laboratory medicine, 2021Co-Authors: Katie M. Moynihan, Kerry Johnson, Mark Rane, Andrew Norman, Susan Humphreys, Christian Stocker, Kristen Gibbons, John RoyAbstract:CONTEXT.— Specific reference intervals (RIs) facilitate accurate interpretation of results. Coagulation assay results may vary by demographics and also between reagents and analyzers used. Current Thromboelastograph 6s (TEG 6s) Hemostasis Analyzer RIs were generated from adult samples. OBJECTIVE.— To generate reagent analyzer-specific pediatric RIs for TEG 6s and coagulation parameters. DESIGN.— A prospective, observational, single-center study of healthy children undergoing general anesthesia (January 3, 2017 to January 3, 2019). Venous blood samples were obtained for TEG 6s (Kaolin, Kaolin-Heparinase, Rapid and Functional Fibrinogen assays) and coagulation parameters (activated partial thromboplastin time, prothrombin time, thrombin clotting time, Echis time, antithrombin activity, and fibrinogen concentration using Instrumentation Laboratory ACL-TOP analyzers). Differences between activated partial thromboplastin time and prothrombin time reagents were investigated using mixed-effects regression, comparing maximum coefficients-of-variation with assay-specific allowable variation. RIs (lower/upper limits 2.5th of 97.5th percentiles) were generated using the following 2 methods: within discrete age-groups (neonates [
-
pediatric Thromboelastograph 6s and laboratory coagulation reference values
Archives of Pathology & Laboratory Medicine, 2021Co-Authors: Katie M. Moynihan, Kerry Johnson, Mark Rane, Andrew Norman, Susan Humphreys, Christian Stocker, Kristen Gibbons, John RoyAbstract:CONTEXT.— Specific reference intervals (RIs) facilitate accurate interpretation of results. Coagulation assay results may vary by demographics and also between reagents and analyzers used. Current Thromboelastograph 6s (TEG 6s) Hemostasis Analyzer RIs were generated from adult samples. OBJECTIVE.— To generate reagent analyzer-specific pediatric RIs for TEG 6s and coagulation parameters. DESIGN.— A prospective, observational, single-center study of healthy children undergoing general anesthesia (January 3, 2017 to January 3, 2019). Venous blood samples were obtained for TEG 6s (Kaolin, Kaolin-Heparinase, Rapid and Functional Fibrinogen assays) and coagulation parameters (activated partial thromboplastin time, prothrombin time, thrombin clotting time, Echis time, antithrombin activity, and fibrinogen concentration using Instrumentation Laboratory ACL-TOP analyzers). Differences between activated partial thromboplastin time and prothrombin time reagents were investigated using mixed-effects regression, comparing maximum coefficients-of-variation with assay-specific allowable variation. RIs (lower/upper limits 2.5th of 97.5th percentiles) were generated using the following 2 methods: within discrete age-groups (neonates [<1 month], infants [1 month-1 year], young children [1-5 years], older children [6-10 years], and adolescents [11-16 years]), and modeled as functions of age and/or sex using quantile regression, including significant fractional polynomial and interaction terms. RESULTS.— Variation between prothrombin time and activated partial thromboplastin time assays using different reagents was clinically significant. Reagent-analyzer specific pediatric RIs were generated using data from 254 children. Discrete and model-based RIs varied by age for all coagulation parameters and TEG 6s variables in all assays. CONCLUSIONS.— We report reagent-analyzer specific pediatric RIs for TEG 6s and coagulation parameters. Observed variation reinforces recommendations for laboratory-specific RIs. These findings improve accuracy of interpretation of clinical results, provide a foundation for comparison and validation of tests in pathology and illustrate feasibility and advantages of model-based RI approaches.
Erik S. Fisher - One of the best experts on this subject based on the ideXlab platform.
-
Thromboelastography with Platelet Studies (TEG® with PlateletMapping®) After Rattlesnake Envenomation in the Southwestern United States Demonstrates Inhibition of ADP-Induced Platelet Activation As Well As Clot Lysis
Journal of Medical Toxicology, 2020Co-Authors: A. Min Kang, Erik S. FisherAbstract:Introduction Hematologic effects of North American rattlesnake envenomation can include fibrinogenolysis and thrombocytopenia, depending on species, geography, and other variables. During treatment, these effects are routinely monitored through assessment of fibrinogen concentrations and platelet counts. However, these tests provide no information about fibrinolysis or platelet dysfunction, both of which can also occur with venom from some species. Methods This was a retrospective chart review of patients admitted to a quaternary care academic hospital (Banner – University Medical Center Phoenix) in the southwestern United States for treatment of rattlesnake envenomation, over an approximately 1-year period from March 2017 through April 2018. Patients who had Thromboelastography with platelet studies (TEG® with PlateletMapping®) during their care were included. Results Twelve patients were identified for this study. Four patients exhibited inhibition of ADP-induced platelet activation: one had normal fibrinogen and platelet count, two had concurrent hypofibrinogenemia, and one had concurrent thrombocytopenia. Crotalidae polyvalent immune Fab (ovine) reversed platelet inhibition in the single patient for whom serial Thromboelastographs were available. Fibrinolysis was present in seven patients and resolved in the two patients with serial Thromboelastographs. Conclusions Inhibition of ADP-induced platelet aggregation and fibrinolysis occurred independent of hypofibrinogenemia and thrombocytopenia, indicating fibrinogen concentration (or protime) and platelet count monitoring alone is insufficient to assess the extent of hematologic toxicity in rattlesnake envenomation. Crotalidae polyvalent immune Fab (ovine) reversed platelet inhibition in one case, suggesting platelet inhibition could also be used in treatment decisions. Fibrinolysis could also be reversed, although the timing to antivenom administration was less clear.
-
Thromboelastography with Platelet Studies (TEG® with PlateletMapping®) After Rattlesnake Envenomation in the Southwestern United States Demonstrates Inhibition of ADP-Induced Platelet Activation As Well As Clot Lysis.
Journal of medical toxicology : official journal of the American College of Medical Toxicology, 2019Co-Authors: A. Min Kang, Erik S. FisherAbstract:Hematologic effects of North American rattlesnake envenomation can include fibrinogenolysis and thrombocytopenia, depending on species, geography, and other variables. During treatment, these effects are routinely monitored through assessment of fibrinogen concentrations and platelet counts. However, these tests provide no information about fibrinolysis or platelet dysfunction, both of which can also occur with venom from some species. This was a retrospective chart review of patients admitted to a quaternary care academic hospital (Banner – University Medical Center Phoenix) in the southwestern United States for treatment of rattlesnake envenomation, over an approximately 1-year period from March 2017 through April 2018. Patients who had Thromboelastography with platelet studies (TEG® with PlateletMapping®) during their care were included. Twelve patients were identified for this study. Four patients exhibited inhibition of ADP-induced platelet activation: one had normal fibrinogen and platelet count, two had concurrent hypofibrinogenemia, and one had concurrent thrombocytopenia. Crotalidae polyvalent immune Fab (ovine) reversed platelet inhibition in the single patient for whom serial Thromboelastographs were available. Fibrinolysis was present in seven patients and resolved in the two patients with serial Thromboelastographs. Inhibition of ADP-induced platelet aggregation and fibrinolysis occurred independent of hypofibrinogenemia and thrombocytopenia, indicating fibrinogen concentration (or protime) and platelet count monitoring alone is insufficient to assess the extent of hematologic toxicity in rattlesnake envenomation. Crotalidae polyvalent immune Fab (ovine) reversed platelet inhibition in one case, suggesting platelet inhibition could also be used in treatment decisions. Fibrinolysis could also be reversed, although the timing to antivenom administration was less clear.
Evan G. Pivalizza - One of the best experts on this subject based on the ideXlab platform.
-
Perioperative Thromboelastography and sonoclot analysis in morbidly obese patients
Canadian Journal of Anaesthesia, 1997Co-Authors: Evan G. Pivalizza, Penelope J. Pivalizza, Liza M. WeavindAbstract:Purpose To investigate perioperative coagulation in morbidly obese (MO) patients with the Thromboelastograph (TEG) and Sonoclot analyzer. Methods Twenty-six consecutive morbidly obese and 26 consecutive lean patients presenting for elective surgery were enrolled in this prospective, observational study. Blood was sampled for TEG and Sonoclot analysis immediately after anaesthetic induction and at the end of surgery in the MO group, and immediately after anaesthetic induction in the lean group. The R and K times, alpha angle, maximum amplitude and percentage fibrinoiysis at 30 and 60 min were recorded from the TEG. The Sonoclot ACT, initial clot rate, peak amplitude and time to peak amplitude were recorded from the Sonoclot. Results The TEG in the MO group demonstrated decreased R and K times (8.6 ± 4.8 vs 11.7 ± 3.9 mm, and 2.8 ± 1.2 vs 3.5 ± 0.9 mm respectively (P < 0.05)), and increased alpha angle (73.7 ± 6.0 vs 66.7 ± 6.0°, P < 0.05) and maximum amplitude (72.0 ± 5.4 vs 67.9 ± 4.4 mm, P < 0.05), without change in fibrinolysis. Sonoclot variables in the MO group included increased clot rate (37.5 ± 11.5 vs 23.9 ± 7.7%, P < 0.05) and decreased time to peak impedance (11.7 ± 5.0 vs 17.5 ± 7.2 min, P < 0.05), without change in Sonoclot ACT or peak signature impedance. Conclusion The MO group demonstrated accelerated fibrin formation, fibrinogen-platelet interaction, and platelet function compared with lean controls but no difference in fibrinolysis. Viscoelastic measures of coagulation may be useful in MO patients, who are at increased risk of thromboembolic events. Objectif Examiner le bilan hémostatique de patients pathologiquement obèses par thromboélastographie (TÉG) et analyse Sonoclot. Méthodes Consécutivement, 26 sujets obèses pathologiques (OP) et 26 sujets maigres programmés pour une chirurgie élective ont participé à cette étude prospective et observationnelle. Chez les obèses, du sang a été prélevé pour l’analyse par TÉG et par Sonoclot immédiatement après l’induction de l’anesthésie et à la fin de la chirurgie et, chez les sujets maigres, immédiatement après l’induction. Les temps R et K, l’angle alpha, l’amplitude maximale et le pourcentage de fibnnolyse à 30 et 60 min ont été enregistrés par TÉG. L’ACT la vitesse initiate de formation du caillot, l’amplitude maximale et le temps d’amplitude maximale ont été enregistrés au Sonoclot. Résultats Dans le groupe OP, la TÉG a révélé une baisse des temps R et K (respectivement 8,6 ± 4,8 vs 11,7 ±3,9 mm et 2,8 ± 1,2 vs 3.5 ± 0,9 mm, P < 0,05) et une augmentation de l’angle alpha (73,7 ± 6,0 vs 66,7 ± 6,0°, P < 0,05) et de l’amplitude maximale (72,0 ± 5,4 vs 67,9 ± 4,4 mm, P < 0,05) sans changement fibrinolytique. Au Sonoclot, dans le groupe OP, on observait une augmentation de la vitesse de formation du caillot (37,5 ± 11,5 vs 23,9 ± 7,7%, P < 0,05) et une diminution du temps d’impédance maximale (11,7 ± 0,5 vs 17,5 ± 7,2 min, P < 0,05) sans changement à l’ACT Sonoclot ou à l’impédance maximaie de signature. Conclusion Dans groupe OP, la formation de fibrine, l’interaction fibrinogène-plaquettes et la fonction plaquettaire sont accélérées comparativement aux contrôles maigres alors que la fibrinolyse est identique. Les mesures viscoélastiques de la coagulation peuvent être utiles chez les obèses pathologiques qui sont à risque d’accidents thromboemboliques.
-
Perioperative Thromboelastography and sonoclot analysis in morbidly obese patients
Canadian journal of anaesthesia = Journal canadien d'anesthesie, 1997Co-Authors: Evan G. Pivalizza, Penelope J. Pivalizza, Liza M. WeavindAbstract:Purpose To investigate perioperative coagulation in morbidly obese (MO) patients with the Thromboelastograph (TEG) and Sonoclot analyzer.
Katie M. Moynihan - One of the best experts on this subject based on the ideXlab platform.
-
Pediatric Thromboelastograph 6s and Laboratory Coagulation Reference Values.
Archives of pathology & laboratory medicine, 2021Co-Authors: Katie M. Moynihan, Kerry Johnson, Mark Rane, Andrew Norman, Susan Humphreys, Christian Stocker, Kristen Gibbons, John RoyAbstract:CONTEXT.— Specific reference intervals (RIs) facilitate accurate interpretation of results. Coagulation assay results may vary by demographics and also between reagents and analyzers used. Current Thromboelastograph 6s (TEG 6s) Hemostasis Analyzer RIs were generated from adult samples. OBJECTIVE.— To generate reagent analyzer-specific pediatric RIs for TEG 6s and coagulation parameters. DESIGN.— A prospective, observational, single-center study of healthy children undergoing general anesthesia (January 3, 2017 to January 3, 2019). Venous blood samples were obtained for TEG 6s (Kaolin, Kaolin-Heparinase, Rapid and Functional Fibrinogen assays) and coagulation parameters (activated partial thromboplastin time, prothrombin time, thrombin clotting time, Echis time, antithrombin activity, and fibrinogen concentration using Instrumentation Laboratory ACL-TOP analyzers). Differences between activated partial thromboplastin time and prothrombin time reagents were investigated using mixed-effects regression, comparing maximum coefficients-of-variation with assay-specific allowable variation. RIs (lower/upper limits 2.5th of 97.5th percentiles) were generated using the following 2 methods: within discrete age-groups (neonates [
-
pediatric Thromboelastograph 6s and laboratory coagulation reference values
Archives of Pathology & Laboratory Medicine, 2021Co-Authors: Katie M. Moynihan, Kerry Johnson, Mark Rane, Andrew Norman, Susan Humphreys, Christian Stocker, Kristen Gibbons, John RoyAbstract:CONTEXT.— Specific reference intervals (RIs) facilitate accurate interpretation of results. Coagulation assay results may vary by demographics and also between reagents and analyzers used. Current Thromboelastograph 6s (TEG 6s) Hemostasis Analyzer RIs were generated from adult samples. OBJECTIVE.— To generate reagent analyzer-specific pediatric RIs for TEG 6s and coagulation parameters. DESIGN.— A prospective, observational, single-center study of healthy children undergoing general anesthesia (January 3, 2017 to January 3, 2019). Venous blood samples were obtained for TEG 6s (Kaolin, Kaolin-Heparinase, Rapid and Functional Fibrinogen assays) and coagulation parameters (activated partial thromboplastin time, prothrombin time, thrombin clotting time, Echis time, antithrombin activity, and fibrinogen concentration using Instrumentation Laboratory ACL-TOP analyzers). Differences between activated partial thromboplastin time and prothrombin time reagents were investigated using mixed-effects regression, comparing maximum coefficients-of-variation with assay-specific allowable variation. RIs (lower/upper limits 2.5th of 97.5th percentiles) were generated using the following 2 methods: within discrete age-groups (neonates [<1 month], infants [1 month-1 year], young children [1-5 years], older children [6-10 years], and adolescents [11-16 years]), and modeled as functions of age and/or sex using quantile regression, including significant fractional polynomial and interaction terms. RESULTS.— Variation between prothrombin time and activated partial thromboplastin time assays using different reagents was clinically significant. Reagent-analyzer specific pediatric RIs were generated using data from 254 children. Discrete and model-based RIs varied by age for all coagulation parameters and TEG 6s variables in all assays. CONCLUSIONS.— We report reagent-analyzer specific pediatric RIs for TEG 6s and coagulation parameters. Observed variation reinforces recommendations for laboratory-specific RIs. These findings improve accuracy of interpretation of clinical results, provide a foundation for comparison and validation of tests in pathology and illustrate feasibility and advantages of model-based RI approaches.