Use of Thromboelastography in Assessment of Snake Bite Coagulopathy.

Background: Monitoring for envenomation coagulopathy following snake bites has traditionally involved using serial coagulation studies.Purpose: Thromboelastography (TEG), with its real-time assessment, could offer an alternative to standard of care. This study aims to evaluate the use of TEG with traditional coagulation labs in the assessment of snake bite coagulopathy.Research Design: A retrospective review of patients who presented to a level 1 trauma center between 2014 and 2020 with snake bite envenomation was conducted, comparing traditional coagulation studies to TEG plus coagulation studies.Results: The 12 patients who had studies within the stipulations of our review were tracked and subsequently progressed well clinically with no adverse effects and ultimately discharged home with an average hospital stay of 2.2 days.Conclusions: Our data suggests that patients can be observed clinically without needing repeat coagulation studies if initial TEG and TCS are within normal limits.

Assessment of a Quantra-Guided Hemostatic Algorithm in High-Bleeding-Risk Cardiac Surgery.

OBJECTIVES: To assess whether a Quantra-guided hemostatic algorithm would reduce transfusion requirement and major bleeding compared with laboratory-guided testing in patients facing high-bleeding-risk cardiac surgery. DESIGN: Single-center before-and-after study. SETTING: University hospital. PARTICIPANTS: Patients facing high-bleeding-risk cardiac surgery with cardiopulmonary bypass. INTERVENTIONS: Hemostatic algorithm was based on standard laboratory testing during the control period, then on the Quantra during the Quantra period. The primary endpoint was the number of red blood cell (RBC) units transfused on day 1 after surgery. MEASUREMENTS AND MAIN RESULTS: After propensity-score matching, 66 patients were included in the Quantra group and 117 in the control group. The Quantra group received fewer RBC units on day 1 than the control group (2 [0-5] v 4 [2-6], p = 0.016, respectively). Intraoperatively, the Quantra group received fewer RBC (2 [0-3] v 3 [1-5], p = 0.005), less fresh frozen plasma (0 [0-3] v 3[2-5], p < 0.0001), and fewer platelet units (7.5 [0-10] v 8.2 [6.3-11.7], p = 0.014). The intraoperative rates of RBC, plasma, and platelet transfusion were reduced (64% v 78%, p = 0.05; 41% v 85%, p < 0.001; 55% v 82%, p = 0.001, respectively). The RBC and plasma transfusions were reduced on days 1, 2, and 7. The incidence of major bleeding on day 1 also was reduced (36% v 56%, p = 0.014). In multivariate analysis, implementation of the Quantra-guided hemostatic algorithm was associated independently with reductions in major bleeding. CONCLUSION: Implementation of a Quantra-based hemostatic algorithm was associated with a decrease in transfusion requirement and major bleeding after high-bleeding-risk cardiac surgery. Randomized trials are needed to confirm these results.

Modified Thromboelastography for Peri-interventional Assessment of Platelet Function in Cardiology Patients: A Narrative Review.

Viscoelastic testing (VET), such as thromboelastography, can measure whole blood coagulation dynamics in real time and is used across a range of clinical settings, including cardiac surgery, liver transplant, and trauma. The use of modified thromboelastography with platelet function assessment (TEG(R) PlateletMapping(R) Assay) can provide an analysis of platelet contribution to hemostasis, including the contribution of the P2Y12 receptor and thromboxane pathway to platelet function. The TEG PlateletMapping Assay has shown high correlation with the current gold standard test of platelet function, light transmission aggregometry, to measure arachidonic acid and adenosine diphosphate agonist-induced platelet activation. Studies have also shown comparable results with other whole blood platelet function tests. In this review, we explore the clinical applications of modified thromboelastography with platelet function assessment. This includes guiding dual antiplatelet therapy in relation to cardiac procedures, such as percutaneous coronary interventions, transcatheter aortic valve replacement, and left atrial appendage closure. We also explore the developing use of thromboelastography in the emergency care setting of coronavirus disease 2019, which is commonly associated with a hypercoagulable and hypofibrinolytic state. Despite a general lack of high-quality, grade 1 evidence regarding the use of modified thromboelastography with platelet function assessment in these disease areas, the ability of the TEG PlateletMapping Assay to measure global hemostasis and platelet reactivity rapidly and to view and evaluate results at the point of care makes it a promising area for further study for managing patient treatment and optimizing hemostatic therapy.

Assessment of agreement between EXTEM and NATEM thromboelastometry measurement assays in critically ill neonates.

OBJECTIVES: To investigate the agreement between the EXTEM and NATEM measurements. METHODS: In this retrospective observational study, EXTEM and NATEM analyses were performed on blood samples from 162 ill neonates, providing 324 paired measurements. The agreement between EXTEM and NATEM measurements was evaluated by the nonparametric spearman's rank correlation to assess the correlation between the paired measurements, by the Bland-Altman analysis for the graphical presentation of the agreement, and by the Deming regression model to assess the significance of the agreement. The agreement between the two methods for the detection of bleeding events was determined by kappa statistic. RESULTS: Strong correlations were found between EXTEM and NATEM measurements for A10, MCF. The Bland-Altman plots showed good agreement for A10, MCF, LI60, and alpha angle parameters, while CT showed a nearly linear slope indicating that bias increased with the mean. The highest agreement for bleeding events was found for the A10 parameter (κ = 0.70, p < .001), while the lowest for the CT parameter (κ = 0.36, p = .94). CONCLUSIONS: NATEM parameters that reflect clot firmness and fibrinolytic activity are strongly correlated with the corresponding EXTEM measurements with a good agreement between them, indicating that these two methods could be used interchangeably.

Dynamic use of fibrinogen under viscoelastic assessment results in reduced need for plasma and diminished overall transfusion requirements in severe trauma.

BACKGROUND: Despite advances in trauma management, half of trauma deaths occur secondary to bleeding. Currently, hemostatic resuscitation strategies consist of empirical transfusion of blood products in a predefined fixed ratio (1:1:1) to both treat hemorrhagic shock and correct trauma-induced coagulopathy. At our hospital, the implementation of a resuscitation protocol guided by viscoelastic hemostatic assays (VHAs) with rotational thromboelastometry has resulted in a goal-directed approach. The objective of the study is twofold, first to analyze changes in transfusion practices overtime and second to identify the impact of these changes on coagulation parameters and clinical outcomes. We hypothesized that progressive VHA implementation results in a higher administration of fibrinogen concentrate (FC) and lower use of blood products transfusion, especially plasma. METHODS: A total of 135 severe trauma patients (January 2008 to July 2019), all requiring and initial assessment for high risk of trauma-induced coagulopathy based on high-energy injury mechanism, severity of bleeding and hemodynamic instability were included. After 2011 when we first modified the transfusion protocol, a progressive change in transfusional management occurred over time. Three treatment groups were established, reflecting different stages in the evolution of our strategy: plasma (P, n = 28), plasma and FC (PF, n = 64) and only FC (F, n = 42). RESULTS: There were no significant differences in baseline characteristics among groups. Progressive implementation of rotational thromboelastometry resulted in increased use of FC over time ( p < 0.001). Regression analysis showed that group F had a significant reduction in transfusion of packed red blood cells ( p = 0.005), plasma ( p < 0.001), and platelets ( p = 0.011). Regarding outcomes, F patients had less pneumonia ( p = 0.019) and multiorgan failure ( p < 0.001), without significant differences for other outcomes. Likewise, overall mortality was not significantly different. However, further analysis comparing specific mortality due only to massive hemorrhage in the F group versus all patients receiving plasma, it was significantly lower ( p = 0.037). CONCLUSION: Implementing a VHA-based algorithm resulted in a plasma-free strategy with higher use of FC and a significant reduction of packed red blood cells transfused. In addition, we observed an improvement in outcomes without an increase in thrombotic complications. LEVEL OF EVIDENCE: Therapeutic/Care Management; Level IV.

Effect of an assessment of fibrin-based rotational thromboelastometry on blood transfusion and clinical outcomes in cardiovascular surgery: A cohort study.

The clinical importance of viscoelastic testing in patient blood management when performing cardiovascular surgery is increasing. We aimed to examine the effect of a blood transfusion protocol including an assessment of fibrin-based rotational thromboelastometry on transfusion volume, mortality, and bleeding complications in patients undergoing cardiac or thoracic aortic surgery. We retrospectively studied a cohort of 376 consecutive patients who underwent cardiopulmonary bypass before (control group: 150 cardiac and 35 thoracic aortic surgeries) and after (assessment group: 154 cardiac and 37 thoracic aortic surgeries) introducing the fibrin polymerization assessment with thromboelastometry in the blood transfusion protocol. The transfusion volume and clinical outcomes were compared between the control and assessment groups, and the standardized (mean) difference (S[M]D) was calculated as an indicator of statistical effect size. Compared with the control group, the assessment group had a lower total blood transfusion volume (mL) in cardiac (2720 ± 1282 vs. 2034 ± 1330, p < 0.0001, [SMD] = 0.68) and thoracic aortic surgeries (5236 ± 2732 vs. 3714 ± 1768, p < 0.0001, SMD = 0.67). The 1-year mortality rates were 1.9 % and 2.7 % in cardiac and thoracic aortic surgeries, respectively. Significant differences were not observed in the 1-year mortality (3.2 % vs. 1.0 %, p = 0.16, relative risk [RR] = 0.32 with 95 % confidence intervals [CI] = 0.06-1.57, SD = 0.15), re-exploration for bleeding (4.8 % vs. 2.6 %, p = 0.28, RR = 0.53 with 95 % CI = 0.18-1.57, SD = 0.12), and major bleeding (17.3 % vs. 13.0 %, p = 0.31, RR = 0.75 with 95 % CI = 0.46-1.22, SD = 0.12) rates between the control and assessment groups. The assessment of fibrin polymerization with thromboelastometry using the blood transfusion protocol reduced the blood transfusion volume in cardiovascular surgery.

Effect of hyperparathyroidism on coagulation: a global assessment by modified rotation thromboelastogram (ROTEM)

Background/aim: Hyperparathyroidism is an endocrine disorder characterized by hypercalcemia. Because of calcium's effects on parathyroid glands, bone, intestines, and kidneys, it has an important place in homeostasis. The results of studies regarding hyperparathyroidism hemostasis are conflicting. Thromboelastography helps to evaluate all steps of hemostatic system. Our aim in this study was to investigate the possible role of hemostatic mechanisms in the development of thrombosis in hyperparathyroid patients with the modified rotation thromboelastogram (ROTEM). Materials and methods: Twenty-two patients with primary hyperparathyroidism (PHPT) and 20 healthy controls were involved. This study was conducted in Eskisehir Osmangazi University Faculty of Medicine, Endocrinology and Hematology clinics for 2 years. The complete blood count, fibrinogen, D-dimer levels, prothrombin time, activated prothrombin time, and ROTEM parameters [clot formation time (CFT), clotting time (CT), and maximum clot formation (MCF)] were determined by two activated tests, INTEM and EXTEM analyses. A thromboelastographic evaluation was performed in the preoperative and postoperative (3 months after surgery) periods. Results: In INTEM assay, the CT (p = 0.012) and CFT (p = 0.07) values were increased in preoperative PHPT patients compared with the control group. Although there was a decrease in the postoperative CT and CFT values, no statistical difference was found. Conclusion: The prolongation of the CT and CFT values were consistent with a hypocoagulable state in patients with PHPT. Hyperparathyroidism causes a hypocoagulable state that can be successfully assessed by ROTEM. Hemostatic changes, do not seem to have an effect on increased cardiovascular mortality.

HLA class I depletion by citric acid, and irradiation of apheresis platelets for transfusion of refractory patients.

BACKGROUND: Patients can form antibodies to foreign human leukocyte antigen (HLA) Class I antigens after exposure to allogeneic cells. These anti-HLA class I antibodies can bind transfused platelets (PLTs) and mediate their destruction, thus leading to PLT refractoriness. Patients with PLT refractoriness need HLA-matched PLTs, which require expensive HLA typing of donors, antibody analyses of patient sera and/or crossmatching. An alternative approach is to reduce PLT HLA Class I expression using a brief incubation in citric acid on ice at low pH. METHODS AND MATERIALS: Apheresis PLT concentrates were depleted of HLA Class I complexes by 5 minutes incubation in ice-cold citric acid, at pH 3.0. Surface expression of HLA Class I complexes, CD62P, CD63, phosphatidylserine, and complement factor C3c was analyzed by flow cytometry. PLT functionality was tested by thromboelastography (TEG). RESULTS: Acid treatment reduced the expression of HLA Class I complexes by 71% and potential for C3c binding by 11.5-fold compared to untreated PLTs. Acid-treated PLTs were significantly more activated than untreated PLTs, but irrespective of this increase in steady-state activation, CD62P and CD63 were strongly upregulated on both acid-treated and untreated PLTs after stimulation with thrombin receptor agonist peptide. Acid treatment did not induce apoptosis over time. X-ray irradiation did not significantly influence the expression of HLA Class I complexes, CD62P, CD63, and TEG variables on acid treated PLTs. CONCLUSION: The relatively simple acid stripping method can be used with irradiated apheresis PLTs and may prevent transfusion-associated HLA sensitization and overcome PLT refractoriness.

Progress curve analysis of microtitre plate plasma clotting assays. Assessment of tissue factor levels.

MTP plasma clotting assays monitor the time course of fibrin formation in re-calcified plasma by absorbance measurements and are increasingly used as alternatives to traditional one-point clot time assays employed in clinical laboratories to detect thrombotic disorders. The parameters derived from these analyses are analogous to thromboelastography viz. time, rate and maximum extent of clot formation. The derived parameters, based on the whole course of the clotting reaction are more robust, informative and quantitative than single-point clot time assays. However, the parameters themselves are usually obtained arbitrarily by crude graphical analysis of subjectively selected points of progress curves. The current work aimed to investigate the sensitivity and reproducibility of an MTP clotting assay and examine its suitability for measuring tissue factor (TF) levels in cell culture medium and patient urine. The results demonstrate that progress curves can be analysed by fitting a logistic equation, derived from a simplified autocatalytic clot formation model. The parameters, maximum amplitude (Fm), rate constant (k), time to half-maximum amplitude (tm) and maximum rate of clot formation (vm), fit a power curve showing limiting effects with increasing TF concentration. Log/log plots of tm and k against TF concentration provide standard curves for assessment of unknowns.

Thromboelastographic Assessment of Fibrinolytic Activity in Postpartum Hemorrhage: A Retrospective Single-Center Observational Study.

BACKGROUND: Postpartum hemorrhage is a leading cause of maternal mortality. Antifibrinolytic therapy has the potential to influence outcomes in postpartum hemorrhage, but the incidence of elevated fibrinolytic activity in postpartum hemorrhage is unknown. METHODS: We retrospectively reviewed thromboelastography (TEG) results obtained for postpartum hemorrhage from 118 deliveries at The University of Chicago. TEG results were obtained as part of our postpartum hemorrhage protocol when blood loss exceeded 500 mL after vaginal delivery or 1000 mL after cesarean delivery. Our primary outcome was the incidence of elevated fibrinolytic activity, which we predefined as clot lysis ≥3% at 30 minutes (Ly30) on kaolin TEG. Platelet-mediated clot retraction can also lead to an elevated Ly30 on kaolin TEG. Therefore, to distinguish between fibrinolysis and clot retraction, we evaluated clot lysis using functional fibrinogen TEG, which contains a platelet inhibitor. We considered a kaolin TEG Ly30 ≥3% in conjunction with a nonzero functional fibrinogen TEG Ly30 suggestive of elevated fibrinolytic activity. We also recorded quantitative blood loss, primary etiology of hemorrhage, standard laboratory measurements of coagulation, and demographic and obstetric characteristics of the study population. RESULTS: The median kaolin TEG Ly30 was 0.2% (interquartile range: 0%-0.8%). Fifteen of 118 women (12.7%; 95% confidence interval, 7.9%-19.9%) had kaolin TEG Ly30 values ≥3%. Of 15 patients with elevated Ly30 values, functional fibrinogen TEG Ly30 was available for 13, of which none demonstrated detectable clot lysis. CONCLUSIONS: Our observation that none of the patients in our sample with kaolin TEG Ly30 values ≥3% had a nonzero functional fibrinogen TEG Ly30 value suggests that the observed elevations in kaolin TEG Ly30 may have been secondary to platelet-mediated clot retraction as opposed to fibrinolysis. Platelet-mediated clot retraction should be distinguished from fibrinolysis when assayed using viscoelastic techniques in postpartum hemorrhage. Further research is necessary to determine the optimal methods to assess fibrinolytic activity in postpartum hemorrhage.

Implementing thrombelastography: Experiences from a level I trauma institution.

Viscoelastic hemostatic assays such as thrombelastography (TEG) and rotational thrombelastometry have proven to be important point-of-care tools in the management of acute traumatic hemorrhage. Despite the availability of prospective studies that have confirmed the utility of TEG in reducing transfusion requirements and mortality in bleeding patients when compared to conventional coagulation tests, many institutions run into barriers implementing these viscoelastic hemostatic assays due to concerns regarding cost and benefit. At our academic Level 1 trauma institution, the Division of Trauma, Critical Care, and Acute Care Surgery advocated for the addition of TEG to the clinical armamentarium of providers caring for injured patients and thus spearheaded the clinical implementation of TEG. With the approval of the central laboratory, the Division developed an extensive and well-trained team to run and interpret TEGs as well as perform machine validation and upkeep. The Division continues to perform point-of-care testing throughout the hospital today.

The strengths and weaknesses of viscoelastic testing compared to traditional coagulation testing.

Optimized acute bleeding management requires timely and reliable laboratory testing to detect and diagnose coagulopathies and guide transfusion therapy. Conventional coagulation tests (CCT) are inexpensive with minimal labor requirements, but CCTs may have delayed turnaround times. In addition, abnormal CCT values may not reflect in vivo coagulopathies that require treatment and may lead to overtransfusion. The use of viscoelastic testing (VET) has been rapidly expanding and is recommended by several recent bleeding guidelines. This review is intended to compare CCT to VET, review the strengths and weaknesses of both approaches, and evaluate and summarize the clinical studies that compared CCT-based and VET-based transfusion algorithms. Most studies of CCT vs VET transfusion algorithms favor the use of VET in the management of massively bleeding patients due to reductions in blood product utilization, bleeding, costs, and lengths of stay.

Viscoelastic testing in liver transplantation.

Despite the lack of large randomized clinical studies, viscoelastic tests (VETs) have been a critical armamentarium for hemostatic control in liver transplantation (LT) since the 1960s. Many transplant institutions have adopted VETs in their clinical practice. Several small-size randomized clinical trials on LT patients have suggested that VET-guided hemostatic treatment algorithms have led to decreased indications for and amounts of transfused blood products, especially fresh-frozen plasma, compared to standard laboratory-based hemostatic management. VETs have also been reported to offer insight into the diagnosis and prediction of LT patients' development of hypercoagulability-related morbidity and mortality. There is still a need for VET device-specific hemostatic algorithms in LT, and clinicians must take into account the tendency to underestimate the coagulation capacity of VETs in patients with end-stage liver disease where hemostasis is rebalanced.

Viscoelastic Tests as Point-of-Care Tests in the Assessment and Management of Bleeding and Thrombosis in Liver Disease.

Viscoelastic point-of-care (VET POC) tests provide a global assessment of hemostasis and have an increasing role in the management of bleeding and blood component delivery across several clinical settings. VET POC tests have a rapid turnaround time, provide a better overall picture of hemostasis, predict bleeding more accurately than conventional coagulation tests, and reduce blood component usage and health care costs. Despite commonly having abnormal conventional coagulation tests, most patients with chronic liver disease have a "rebalanced" hemostasis. However, this hemostatic balance is delicate and these patients are predisposed to both bleeding and thromboembolic events. Over recent years, VET POC tests have been increasingly studied for their potential as better functional tests of hemostasis in liver disease patients. This review provides a background on the most common VET POC tests (thromboelastography and rotational thromboelastometry) and discusses the current evidence for these tests in the prediction and management of bleeding and thrombosis in patients with chronic liver disease, and in liver resection and transplant. With the recent publication of several randomized controlled trials, there is growing evidence that VET POC tests may be used to improve bleeding risk assessment and reduce blood product use in liver disease patients outside of the transplant setting. However, consensus is still lacking regarding the VET POC tests' thresholds that should be used to trigger blood product transfusion. VET POC tests also show promise in predicting thrombosis in patients with liver disease, but further research is needed before they can be used to guide anticoagulant therapy.

Evaluation of Bleeding Phenotype of Inherited Factor VII Deficiency in Children With a Bleeding Assessment Tool and Global Assays.

INTRODUCTION: Inherited factor VII (FVII) deficiency is the most common of the rare bleeding disorders and shows a heterogenous distribution of bleeding phenotypes independent of factor activity level. The bleeding score (BS) evaluates the phenotype of patients with rare bleeding disorders. Thromboelastography (TEG) and thrombin generation assays (TGAs) are 2 methods to evaluate global hemostasis, and controversially both tests are useful for identifying different bleeding tendency phenotypes. The purpose of this study was to investigate the use of the BS and global assays (TEG and TGAs) to predict the bleeding phenotype of inherited FVII deficiency. MATERIALS AND METHODS: A total of 27 patients with FVII deficiency were evaluated with the BS and global hemostasis assays. RESULTS: The BS was compatible with disease severity according to the FVII activity level (P<0.05) but the BS and bleeding grade of patients did not show a statistically significant correlation with factor activity level (P>0.05). No significant correlation was observed between the factor activity level and any TEG parameter (P>0.05). The factor activity level was negatively correlated with the lag time of the TGA on the contrary positively correlated with the peak thrombin time of the TGA (P<0.05). CONCLUSIONS: The global assays do not successfully predict the bleeding phenotype. The BS is a more suitable tool than conventional and global assays for predicting the bleeding phenotype.

Assessment of Coagulation by Thromboelastography During Ongoing Postpartum Hemorrhage: A Retrospective Cohort Analysis.

BACKGROUND: Rapid assessment of hemostasis during postpartum hemorrhage (PPH) is essential to allow characterization of coagulopathy, to estimate bleeding severity, and to improve outcome. Point of care (POC) coagulation monitors could be of great interest for early diagnosis and treatment of coagulation disorders in PPH. METHODS: Women with ongoing PPH >500 mL who clinically required an assessment of coagulation with thromboelastography (TEG) were included. The primary aim of this retrospective observational cohort study was to assess the predictive accuracy of TEG parameters for the diagnosis of coagulation disorders (hypofibrinogenemia ≤2 g/L, thrombocytopenia ≤80,000/mm, prothrombin ratio ≤50%, or activated partial thromboplastin time ratio ≥1.5) during PPH. The analyzed TEG parameters were Kaolin-maximum amplitude (K-MA), Kaolin-maximum rate of thrombus generation using G (K-MRTGG), functional fibrinogen-maximum amplitude (FF-MA), and functional fibrinogen-maximum rate of thrombus generation using G (FF-MRTGG). Secondary aims of this study were (1) comparison of the time delay between classical parameters and velocity curve-derived parameters (K-MA versus K-MRTGG and FF-MA versus FF-MRTGG) and (2) evaluation of the accuracy of TEG parameters to predict severe hemorrhage estimated by calculated blood losses. RESULTS: Ninety-eight patients were included with 98 simultaneous TEG analyses and laboratory assays. All parameters had an excellent predictive performance. For the Kaolin assay, no significant difference was evidenced between K-MA and K-MRTGG for the predictive performance for hypofibrinogenemia ≤2 g/L and/or thrombocytopenia ≤80,000/mm (respective area under the curve [AUC], 0.970 vs 0.981). For the functional fibrinogen assay, no significant difference was evidenced between FF-MA and FF-MRTGG for the predictive performance for hypofibrinogenemia ≤2 g/L (respective AUC, 0.988 vs 0.974). For both assays, the time to obtain results was shorter for the velocity parameters (K-MRTGG: 7.7 minutes [2.4 minutes] versus K-MA: 24.7 minutes [4.2 minutes], P < .001; FF-MRTGG: 2.7 minutes [2.7 minutes] versus FF-MA: 14.0 minutes [4.3 minutes], P < .001). All TEG parameters derived from the Kaolin and functional fibrinogen assays and Clauss fibrinogen were significantly predictive of severe PPH >2500 mL. CONCLUSIONS: During PPH, when coagulation assessment is indicated, TEG provides a rapid and reliable detection of hypofibrinogenemia ≤2 g/L and/or thrombocytopenia ≤80,000/mm. No difference in performance was evidenced between the velocity-derived parameters (K-MRTGG and FF-MRTGG) and the classical parameters (K-MA and FF-MA). However, velocity-derived parameters offer the advantage of a shorter time to obtain results: FF-MRTGG parameter is available within ≤5 minutes. POC assessment of hemostasis during PPH management may help physicians to diagnose clotting disorders and to provide appropriate hemostatic support.

[Rotational thromboelastometry assessment of ballanced crystalloid, hydroxyethyl starch and gelatin effects on coagulation: a randomized trial]. / Tromboelastometria rotacional na avaliação dos efeitos de cristaloides balanceados, hidroxietilamido e gelatina na coagulação: estudo randômico.

BACKGROUND AND OBJECTIVES: Modern crystalloid and colloid solutions are balanced solutions which are increasingly used in perioperative period. However, studies investigating their negative effect on whole blood coagulation are missing, and vivid debate is going on about which solution has the minimal coagulopathy effect. The aim of our study was to assess the effect of modern fluid solutions on whole blood coagulation using rotational thromboelastometry. METHODS: Blood samples were obtained from 30 patients during knee arthroscopy before and after administration of 500mL of crystalloid, Hydroxyethyl Starch and gelatin according to the randomization. Rotational thromboelastometry (Extem, Intem and Fibtem tests) was used to assess negative effect of fluid solutions on whole blood coagulation. RESULTS: In Extem test, the initiation phase of fibrin clot formation represented by CT parameter was not influenced by any fluid solution (p>0.05). The speed of clot formation represented by CFT and α angle was impaired by Hydroxyethyl Starch and gelatin but not by crystalloids (p<0.05). The strength of formatted coagulum represented by MCF parameter was impaired both in Extem and Fibtem test by HES and in Fibtem also by crystalloids (p<0.05). Intem test was not negatively influenced by any crystalloid or colloid solution in any parameter (p>0.05). CONCLUSION: Extem test appears to be sensitive to coagulopathy effect of modern colloids and crystalloids. Hydroxyethyl starch has the most obvious negative effect on clot formation followed by gelatin and finally by crystalloids. Intem test seems to be insensitive to adverse effect of modern colloids and crystalloids.

Rotational thromboelastometry assessment of ballanced crystalloid, hydroxyethyl starch and gelatin effects on coagulation: a randomized trial / Tromboelastometria rotacional na avaliação dos efeitos de cristaloides balanceados, hidroxietilamido e gelatina na coagulação: estudo randômico

Abstract Background and objectives Modern crystalloid and colloid solutions are balanced solutions which are increasingly used in perioperative period. However, studies investigating their negative effect on whole blood coagulation are missing, and vivid debate is going on about which solution has the minimal coagulopathy effect. The aim of our study was to assess the effect of modern fluid solutions on whole blood coagulation using rotational thromboelastometry. Methods Blood samples were obtained from 30 patients during knee arthroscopy before and after administration of 500 mL of crystalloid, Hydroxyethyl Starch and gelatin according to the randomization. Rotational thromboelastometry (Extem, Intem and Fibtem tests) was used to assess negative effect of fluid solutions on whole blood coagulation. Results In Extem test, the initiation phase of fibrin clot formation represented by CT parameter was not influenced by any fluid solution (p > 0.05). The speed of clot formation represented by CFT and α angle was impaired by Hydroxyethyl Starch and gelatin but not by crystalloids (p < 0.05). The strength of formatted coagulum represented by MCF parameter was impaired both in Extem and Fibtem test by HES and in Fibtem also by crystalloids (p < 0.05). Intem test was not negatively influenced by any crystalloid or colloid solution in any parameter (p > 0.05). Conclusion Extem test appears to be sensitive to coagulopathy effect of modern colloids and crystalloids. Hydroxyethyl starch has the most obvious negative effect on clot formation followed by gelatin and finally by crystalloids. Intem test seems to be insensitive to adverse effect of modern colloids and crystalloids.

Resumo Justificativa e objetivos Os cristaloides e coloides modernos são soluções balanceadas e cada vez mais utilizadas no período perioperatório. No entanto, não há estudos que avaliem seu efeito negativo na coagulação do sangue total e o intenso debate sobre a solução que cause um efeito mínimo na coagulopatia permanece. O objetivo de nosso estudo foi avaliar o efeito das soluções líquidas modernas na coagulação do sangue total com o uso da tromboelastometria rotacional. Métodos De acordo com a randomização, amostras de sangue foram colhidas de 30 pacientes durante a artroscopia de joelho, antes e após a administração de 500 mL de cristaloides, hidroxietilamido e gelatina. A tromboelastometria rotacional (testes Extem, Intem e Fibtem) foi utilizada para avaliar o efeito negativo das soluções líquidas na coagulação do sangue total. Resultados No teste Extem, a fase de iniciação da formação de coágulos de fibrina representada pelo parâmetro CT não foi influenciada por qualquer solução líquida (p > 0,05). A velocidade da formação de coágulos representada pelo CFT e pelo ângulo α foi prejudicada pelo hidroxietilamido e pela gelatina, mas não pelos cristaloides (p < 0,05). A força do coágulo formatado representado pelo parâmetro MCF foi prejudicada tanto no teste Extem quanto no teste Fibtem pelo HES e no teste Fibtem também pelos cristaloides (p < 0,05). O teste Intem não foi influenciado negativamente por nenhuma solução cristaloide ou coloide em nenhum parâmetro (p > 0,05). Conclusão O teste Extem parece ser sensível ao efeito de coagulopatia dos coloides e cristaloides modernos. O hidroxietilamido apresentou o efeito negativo mais óbvio na formação do coágulo, seguido pela gelatina e finalmente pelos cristaloides. O teste Intem parece ser insensível ao efeito adverso dos coloides e cristaloides modernos.