Preoperative thromboelastography parameters in predicting the tumour stage of oral squamous cell carcinoma.

BACKGROUND: A variety of solid tumours, including oral squamous cell carcinoma (OSCC), can cause coagulation abnormalities, and this phenomenon is known as tumour-associated hypercoagulation. We aimed to explore the preoperative thromboelastography (TEG) parameter profiles of OSCC patients, and to investigate their trends in relation to tumour stage progression, and to evaluate their value for predicting cervical lymph node metastasis. METHODS: Data on thromboelastographic parameters and conventional coagulation indices were retrospectively collected, and comparisons were performed among preoperative primary OSCC patients (n = 311), recurrent/metastatic OSCC patients (n = 44) and a control group (n = 71). Among primary OSCC patients, the correlation with tumour stage and the predictive role of cervical lymph node metastasis were analyzed. RESULTS: Hypercoagulability occurred in OSCC patients and tended to become more pronounced as the tumour progressed. The whole-time phase of coagulation increased with increasing T stage, while the early phase of coagulation increased with increasing N stage. CONCLUSIONS: Preoperative TEG parameters are closely related to tumour stage and progression, suggesting that TEG can be used as an important indicator for predicting tumour stage and as a potential biomarker.

A multi-center, double-blind, placebo-controlled, randomized, parallel-group, non-inferiority study to compare the efficacy of goal-directed tranexamic acid administration based on viscoelastic test versus preemptive tranexamic acid administration on postoperative bleeding in cardiovascular surgery (GDT trial).

BACKGROUND: Tranexamic acid (TXA) effectively attenuates hyperfibrinolysis and preemptive administration has been employed to reduce bleeding and blood transfusions in various surgical settings. However, TXA administration could be associated with adverse effects, such as seizures and thromboembolic risks. While patients with fibrinolysis shutdown showed greater thromboembolic complications and mortality, TXA administration may aggravate the degree of shutdown in these patients. Selective TXA administration based on the results of rotational thromboelastometry (ROTEM) would be non-inferior to preemptive TXA administration in reducing postoperative bleeding and beneficial in reducing its risks in patients undergoing cardiovascular surgery. METHODS: This non-inferiority, randomized, double-blind, placebo-controlled, multicenter trial will be performed in 3 tertiary university hospitals from August 2023 to March 2025. Seven hundred sixty-four patients undergoing cardiovascular surgery will be randomly allocated to get TXA as a preemptive (Group-P) or goal-directed strategy (Group-GDT) in each institution (with a 1:1 allocation ratio). After anesthesia induction, TXA (10 mg/kg and 2 mg/kg/h) and a placebo are administered after anesthesia induction in Group-P and Group-GDT, respectively. ROTEM tests are performed immediately before weaning from CPB and at the considerable bleeding post-CPB period. After getting the test results, a placebo is administered in Group-P (regardless of the test results). In Group-GDT, placebo or TXA is administered according to the results: placebo is administered if the amplitude at 10 min (A10-EXTEM) is ≥ 40 mm and lysis within 60 min (LI60-EXTEM) of EXTEM assay is ≥ 85%, or TXA (20 mg/kg) is administered if A10-EXTEM is < 40 mm or LI60-EXTEM is < 85%. The primary outcome is inter-group comparisons of postoperative bleeding (for 24 h). The secondary measures include comparisons of perioperative blood transfusion, coagulation profiles, reoperation, thromboembolic complications, seizures, in-hospital mortality, fibrinolysis phenotypes, and hospital costs. DISCUSSION: The absence of inter-group differences in postoperative bleeding would support the selective strategy's non-inferiority in reducing postoperative bleeding in these patients. The possible reduction in thromboembolic risks, seizures, and fibrinolysis shutdown in Group-GDT would support its superiority in reducing TXA-induced adverse events and the cost of their management. TRIAL REGISTRATION: This trial was registered at ClinicalTrials.gov with the registration number NCT05806346 on March 28, 2023. TRIAL STATUS: recruiting. Issue date: 2023 March 28 (by Tae-Yop Kim, MD, PhD). The trial was registered in the clinical registration on March 28, 2023 (ClinicalTrials.gov, NCT05806346) and revised to the latest version of its protocol (version no. 8, August 26, 2024) approved by the institutional review boards (IRBs) of all 3 university hospitals (Konkuk University Medical Center, 2023-07-005-001, Asan Medical Center, 2023-0248, and Samsung Medical Center, SMC 2023-06-048-002). Its recruitment was started on August 1, 2023, and will be completed on December 31, 2024. Protocol amendment number: 08 (protocol version 08, August 26, 2024). Revision chronology: 2023 March 28:Original. 2023 April 10:Amendment No 01. The primary reason for the amendment is the modification of Arms (adding one arm for sub-group analyses) and Interventions, Outcome Measures, Study Design, Study Description, Study Status, Eligibility, and Study Identification. 2023 May 03:Amendment No 02. The primary reason for the amendment is to modify the Outcome Measures and update the study status. 2023 July 06:Amendment No 03. The primary reason for amendment is to update the chronological study status. 2023 July 07:Amendment No 04. The primary reason for the amendment is the modification of study information (the treatment category was changed to diagnostic, and Phase 4 was changed to not applicable) and a chronological update on the study status. 2023 September 12:Amendment No 06. The primary reason for the amendment is a chronological update in the study status and the inclusion of additional information regarding contacts/locations and oversight. 2023 December 29:Amendment No 07. The primary reason for the amendment is to modify the outcome measures (including detailed information on outcome measures, addition of extra secondary measures, and chronological updates in study status). 2024 August 26:Amendment No 08. The primary reason for the amendment is to add detailed descriptions regarding data handling and the names and roles of the participating institutions and to update the chronological process of the trial.

Trial Of Pathogen-reduced Cryoprecipitate vs. Cryoprecipitated AHF to Lower Operative Transfusions (TOP-CLOT): study protocol for a single center, prospective, cluster randomized trial.

BACKGROUND: Intraoperative hemorrhage in cardiac surgery increases risk of morbidity and mortality. Low pre-operative and perioperative levels of fibrinogen, a key clotting factor, are associated with severity of hemorrhage and increased transfusion of blood components. The ability to supplement fibrinogen during hemorrhagic resuscitation is delayed 45-60 min because cryoprecipitated antihemophilic factor (cryo AHF) is stored frozen, due to a short post-thaw shelf life. Pathogen Reduced Cryoprecipitated Fibrinogen Complex (INTERCEPT Fibrinogen Complex, IFC) can be kept thawed, at room temperature, for up to 5 days, making it possible to be immediately available for hemorrhaging patients. This trial will investigate if earlier correction of acquired hypofibrinogenemia with IFC in hemorrhaging cardiac surgery patients reduces the total number of perioperatively transfused allogeneic blood products (red blood cells, plasma, and platelets) as compared to cryo AHF. METHODS: This is a single center, prospective, cluster randomized trial with an adaptive design. Acquired hypofibrinogenemia will be assessed by rotational thromboelastometry (ROTEM) and the threshold for cryo AHF/IFC transfusion defined as FIBTEM A10 ≤ 10 mm in bleeding patients. IFC/cryo AHF will be randomized by 1-month blocks. Cardiac surgery patients will be enrolled in the study if they have an eligible procedure and at least one dose of a cryo AHF/IFC product (approximately 2 g fibrinogen) is transfused. Data from the electronic health record, including the blood bank and lab information systems, will be prospectively collected from the health system's data warehouse. DISCUSSION: This trial aims to provide evidence of the clinical efficacy of utilizing readily available thawed IFC during acute bleeding in the cardiac surgery setting compared to traditional cryo AHF. TRIAL REGISTRATION: ClinicalTrials.gov NCT05711524. Feb 3, 2023.

Thromboelastography as an early prediction method for hypofibrinogenemia in emergency department patients with primary postpartum hemorrhage.

BACKGROUND: Timely and accurate assessment of coagulopathy is crucial for the management of primary postpartum hemorrhage (PPH). Thromboelastography (TEG) provides a comprehensive assessment of coagulation status and is useful for guiding the treatment of hemorrhagic events in various diseases. This study aimed to evaluate the role of TEG in predicting hypofibrinogenemia in emergency department (ED) patients with primary PPH. METHODS: We conducted a retrospective observational study in the ED of a university-affiliated tertiary hospital between November 2015 and August 2023. TEG was performed upon admission. The cutoff value for hypofibrinogenemia was 200 mg/dL. The primary outcome was the presence of hypofibrinogenemia. RESULTS: Among the 174 patients, 73 (42.0%) had hypofibrinogenemia. The need for massive transfusion was higher in the hypofibrinogenemia group (37.0% vs. 5.0%, p < 0.001). Among the TEG parameters, all values were significantly different between the groups, except for lysis after 30 min, suggesting a tendency toward hypocoagulability. Multivariable analysis revealed that the alpha angle (odds ratio (OR) 0.924, 95% confidence interval (CI) 0.876-0.978) and maximum amplitude (MA) (OR 0.867, 95% CI 0.801-0.938) were independently associated with hypofibrinogenemia. The optimal cutoff values for the alpha angle and maximum amplitude (MA) for hypofibrinogenemia were 63.8 degrees and 56.1 mm, respectively. CONCLUSION: Point-of-care TEG could be a valuable tool for the early identification of hypofibrinogenemia in ED patients with primary PPH.

Improving safety: Neuraxial blockade guided by thromboelastography for patients with uncertain coagulation profile.

ABSTRACT: Neuraxial blockade procedures are essential for anesthesia and pain management but pose risks in patients with uncertain coagulation profiles. Traditional coagulation tests often fail to predict bleeding risks associated with neuraxial blockade. Thromboelastography (TEG) offers real-time insights into coagulation status, potentially improving safety outcomes. In this case series, six patients underwent neuraxial blockade guided by TEG analysis. An individualized anesthetic plan was formulated based on TEG findings to mitigate bleeding risks while ensuring pain management. Tailoring anesthetic techniques to real-time TEG data improved safety outcomes with minimized bleeding complications and satisfactory pain control. In conclusion, neuraxial blockade guided by TEG enhances safety in patients with uncertain coagulation profiles. Further studies are needed to validate benefits in broader clinical settings.

Intrinsic or Nonintrinsic End-stage Liver Disease and Its Association With Thromboelastography-based Coagulation States in Patients Undergoing Liver Transplantation: A Retrospective Cohort Study.

OBJECTIVES: Perioperative coagulation management in liver transplantation recipients is challenging. Viscoelastic testing with rotational thromboelastography (TEG) can help quantify hemostatic profiles. The current work aimed to investigate whether the etiology of end-stage liver disease, pretransplant disease severity, or pretransplant thrombotic or bleeding complications are associated with specific TEG patterns. DESIGN: Retrospective cohort study. SETTING: Single quaternary care hospital. PARTICIPANTS: A total of 1,078 adult liver transplant patients. INTERVENTIONS: The primary exposure was the etiology of end-stage liver disease classified as either intrinsic or nonintrinsic (eg, biliary obstruction or cardiovascular). Secondary exposures were patients' preoperative Model for End-Stage Liver Disease (MELD) score, Child-Pugh class, presence of major preoperative thrombotic complications, and major bleeding complications. MEASUREMENTS AND MAIN RESULTS: Patients with intrinsic liver disease (84%) showed higher odds of hypocoagulable (odds ratio [OR]: 3.70, 95% confidence interval [CI]: 1.94-7.07, p < 0.0001) and mixed TEG patterns (OR: 4.59, 95% CI: 2.07-10.16, p = 0.0002) compared with those with nonintrinsic disease. Increasing MELD scores correlated with higher odds of hypocoagulable (OR: 1.14, 95% CI: 1.08-1.19, p < 0.0001) and mixed TEG patterns (OR: 1.08, 95% CI: 1.03-1.14, p = 0.0036). Child-Pugh class C was associated with higher odds of hypocoagulable (OR: 8.55, 95% CI: 3.26-22.42, p < 0.0001) and mixed patterns (OR: 12.48, 95% CI: 3.89-40.03, p < 0.0001). Major preoperative thrombotic complications were not associated with specific TEG patterns, although an interaction with liver disease severity was observed. CONCLUSIONS: Liver transplantation candidates with intrinsic liver disease tend to exhibit hypocoagulable TEG patterns, while nonintrinsic disease is associated with hypercoagulability. Increasing end-stage liver disease severity, as evidenced by increasing MELD scores and higher Child-Pugh classification, was also associated with hypocoagulable TEG patterns.

Hyperfibrinolysis: potential guidance for decision-making to avoid futile extracorporeal cardiopulmonary resuscitation.

Out-of-hospital cardiac arrest (OHCA) is associated with very poor outcomes. Extracorporeal cardiopulmonary resuscitation (eCPR) for selected patients is a potential therapeutic option for refractory cardiac arrest. However, randomised controlled studies applying eCPR after refractory OHCA have demonstrated conflicting results regarding survival and good functional neurological outcomes. eCPR is an invasive, labour-intensive, and expensive therapeutic approach with associated side-effects. A rapid monitoring device would be valuable in facilitating selection of appropriate patients for this expensive and complex treatment. To this end, rapid diagnosis of hyperfibrinolysis, or premature clot dissolution, diagnosed by viscoelastic testing might represent a feasible option. Hyperfibrinolysis is an evolutionary response to low or no-flow states. Studies in trauma patients demonstrate a high mortality rate in those with established hyperfibrinolysis upon emergency room admission. Similar findings have now been reported for the first time in OHCA patients. Hyperfibrinolysis upon admission diagnosed by rotational thromboelastometry was strongly associated with mortality and poor neurological outcomes in a small cohort of patients treated with extracorporeal membrane oxygenation.

Association of hyperfibrinolysis with poor prognosis in refractory circulatory arrest: implications for extracorporeal cardiopulmonary resuscitation.

BACKGROUND: Identifying candidates for extracorporeal cardiopulmonary resuscitation (eCPR) is challenging, and novel predictive markers are urgently needed. Hyperfibrinolysis is linked to tissue hypoxia and is associated with poor outcomes in out-of-hospital cardiac arrest (OHCA). Rotational thromboelastometry (ROTEM) can detect or rule out hyperfibrinolysis, and could, therefore, provide decision support for initiation of eCPR. We explored early detection of hyperfibrinolysis in patients with refractory OHCA referred for eCPR. METHODS: We analysed ROTEM results and resuscitation parameters of 57 adult patients with ongoing OHCA who presented to our ICU for eCPR evaluation. RESULTS: Hyperfibrinolysis, defined as maximum lysis ≥15%, was present in 36 patients (63%) and was associated with higher serum lactate, lower arterial blood pH, and increased low-flow intervals. Of 42 patients who achieved return of circulation, 28 had a poor 30-day outcome. The incidence of hyperfibrinolysis was higher in the poor outcome group compared with patients with good outcomes (75% [21 of 28] vs 7.1% [1 of 14]; P<0.001). The ratio of EXTEM A5 to lactate concentration showed good predictive value in detecting hyperfibrinolysis (AUC of 0.89 [95% confidence interval 0.8-1]). CONCLUSIONS: Hyperfibrinolysis was common in patients with refractory cardiac arrest, and was associated with poor prognosis. The combination of high lactate with early clot firmness values, such as EXTEM A5, appears promising for early detection of hyperfibrinolysis. This finding could facilitate decisions to perform eCPR, particularly for patients with prolonged low-flow duration but lacking hyperfibrinolysis.

Rotational thromboelastometry predicts future bleeding events in patients with cirrhosis.

BACKGROUND AND AIMS: Patients with cirrhosis of the liver are in a delicate state of rebalanced haemostasis and are at risk of developing both bleeding and thrombotic complications. Conventional haemostatic tests are unable to predict bleeding and thrombosis in these patients. We aimed to explore the role of Rotational Thromboelastometry (ROTEM) in predicting bleeding and thrombotic events in patients with cirrhosis. METHODS: We conducted a prospective cohort study of patients with cirrhosis at two metropolitan hospitals. All patients underwent ROTEM analysis and were then followed to record any bleeding and thrombotic events. Univariate and multivariate logistic regression analyses were performed to explore associations with bleeding and thrombotic events. RESULTS: Nineteen of the 162 patients recruited experienced a bleeding event within one year of ROTEM analysis. On univariate analysis, maximum clot firmness (MCF) using both EXTEM and INTEM tests was significantly reduced in patients who had a bleeding event, compared to those who did not (50 mm vs. 57 mm, p < 0.01 and 48 mm vs. 54 mm, p < 0.01, respectively). In addition, on univariate analysis, clotting time (CT) in the INTEM test was prolonged in the bleeding group (214 s vs. 198 s, p = 0.01). On multivariate analysis, only MCFEX was a significant predictor of bleeding events. In contrast, there was no association found between ROTEM parameters and development of thrombosis within a one-year period. CONCLUSIONS: ROTEM may provide a useful tool in predicting future bleeding events in patients with cirrhosis. Larger studies are required to further validate this finding and explore its application in clinical practice.

Utility of thromboelastography with platelet mapping for monitoring platelet transfusion in qualitative platelet disorders.

BACKGROUND: Patients with pathogenic variants in RASGRP2 (inherited platelet disorder (IPD)-18) exhibit normal platelet counts but impaired platelet aggregation and αIIbß3 activation. Moderate-to-severe bleeding episodes require patients to be transfused with platelets and/or pro-hemostatic agents. We recently demonstrated that hemostatic efficacy of transfused platelets is limited by dysfunctional endogenous platelets in a mouse model of IPD-18 (Rasgrp2-/- mice), as dysfunctional platelets were recruited to the forming hemostatic plug but did not participate in clot contraction. Thus, higher amounts of transfused platelets were required to outcompete these dysfunctional cells and to reverse bleeding. OBJECTIVE: We here studied the usefulness of thromboelastography with platelet mapping (TEG-PM) for ex vivo monitoring of the hemostatic potential in Rasgrp2-/- mice transfused with various amounts of wild-type (WT) platelets. METHODS: Whole blood (WB) samples from WT and Rasgrp2-/- mice were tested in TEG-PM and parameters for clot formation and contraction (K time, α-angle, maximum amplitude [MA]) were measured. RESULTS: Rasgrp2-/- WB samples did not contract in TEG-PM, consistent with a critical role of this protein in αIIbß3 activation. Addition of WT platelets improved TEG parameters in a ratio-dependent manner, consistent with our recent in vivo studies showing impaired hemostasis at a 5:1, but not at a 2:1 ratio of mutant to WT platelets. K and α values were identified as better predictors of transfusion efficacy than MA, the most platelet-dependent TEG parameter. CONCLUSION: This proof-of-concept study supports the use of TEG-PM to monitor platelet transfusion ratios and hemostatic potential in IPD-18 and potentially other platelet disorders.

Platelet Contribution and Endothelial Activation and Stress Index-Potential Mortality Predictors in Traumatic Brain Injury.

Coagulopathy and traumatic brain injury (TBI) are complexly intertwined. In isolated TBI, coagulopathy may contribute to hemorrhagic lesion development, progression, or recurrence, as it may lead to a particular pattern of coagulopathy called TBI-induced coagulopathy (TBI-IC). We performed a retrospective and descriptive evaluation of 63 patients admitted to the Emergency Clinical Hospital Bucharest with the diagnosis of moderate/severe brain injury. In addition to demographic data, all included patients had a complete paraclinical evaluation that included rotational thromboelastometric (ROTEM) blood-clot analysis. The platelet component (PLTEM) and the endotheliopathy activation and stress index score (EASIX) were calculated. These parameters were presented comparatively according to survival at 30 days and helped define the two study groups: survivors and non-survivors at 30 days. The contribution of platelets to clot strength is derived from maximum clot elasticity (MCE) and maximum clot firmness (MCF). MCE is defined as (MCF × 100)/(100 - MCF), and PLTEM is defined as EXTEM MCE-FIBTEM MCE. EASIX is a novel biomarker recently studied in TBI patients, calculated according to the following formula: lactate dehydrogenase (U/L) × creatinine (mg/dL)/platelets (109 cells/L). Regarding the demographic data, there were no significant differences between the survivors and non-survivors. All ROTEM parameters related to clot amplitude (A5, A10, A20, MCF in EXTEM and FIBTEM channels) were higher in the group of patients who survived. Also, PLTEM was decreased in the group of deceased patients (89.71 ± 22.86 vs. 132.3 ± 16.56 p < 0.0001). The cut-off point determined with the ROC curve is 114.10, with a sensitivity of 94.74% and a specificity of 93.18%, for the detection of the negative prognosis (death at 30 days). The EASIX score was significantly higher in the patients who survived the traumatic event, with a median difference value of 1.15 (p < 0.0001). The ROC analysis of this biomarker highlights a cut-off point of 2.12, with a sensitivity of 88.64% and a specificity of 94.74% (AUC = 0.95, p < 0.0001), for the prediction of mortality. The comparative analysis of the two studied markers was performed using the Cox proportional hazard ratio and highlighted the greater influence that PLTEM has on survival time (b value = -0.05, p < 0.0001) compared to EASIX (b value = 0.49, p = 0.0026). The present retrospective study indicates the potential of the TBI-IC reflecting parameters PLTEM and EASIX as markers of mortality prognosis. Larger prospective studies are needed to confirm their combined prognostic value and use in decision-making and reduction in the burden of disease by adequate allocation of resources in a personalized and timely manner.

Blood Lines: Intraspecific and Interspecific Variations in Anticoagulant Actions of Agkistrodon Viperid Venoms.

This study investigated the intraspecific and interspecific variability in the venom effects of Agkistrodon viperid snake species and subspecies (eleven venoms total) on plasma clotting times, fibrinogen levels, and fibrin clot strength. Significant delays in plasma clotting time were observed for A. conanti, A. contortrix mokasen, A. contortrix phaeogaster, A. howardgloydi, A. piscivorus leucostoma, and A. piscivorus piscivorus. Notably, the phylogenetically disjunct lineages A. conanti, A. contortrix mokasen, and A. howardgloydi exhibited the most potent anticoagulant effects, indicating the independent amplification of a basal trait. Inhibition assays with the activated clotting enzymes Factors XIa, IXa, Xa, and IIa (thrombin) revealed that FXa inhibition is another basal trait amplified independently on multiple occasions within the genus, but with A. howardgloydi, notably more potent than all others. Phospholipid degradation and zymogen destruction were identified as mechanisms underlying the variability in venom effects observed experimentally and in previous clinical reports. Thromboelastography demonstrated that the venoms did not clot fibrinogen directly but affected fibrin clot strength by damaging fibrinogen and that thrombin was subsequently only able to cleave into weak, unstable clots. The ability to activate Protein C, an endogenous anticoagulant enzyme, varied across species, with some venoms exceeding that of A. contortrix contortrix, which previously yielded the protein diagnostic agent Protac®. Phylogenetic analysis suggested that both fibrinogen degradation and Protein C activation were each amplified multiple times within the genus, albeit with negative correlation between these two modes of action. This study highlights the evolutionary, clinical, and biodiscovery implications of venom variability in the Agkistrodon species, underscoring their dynamic evolution, emphasising the need for tailored clinical approaches, and highlighting the potential for novel diagnostic and therapeutic developments inspired by the unique properties of snake venoms.

Analyzing venous thromboembolism risk in malignant tumors: thromboelastogram and coagulation factors study.

Aim: This retrospective clinical study was designed to examine the predictive value of thromboelastography (TEG) combined with coagulation function for venous thromboembolism (VTE) in hospitalized patients with cancer. Materials & methods: Among 215 patients admitted between May 2020 and January 2022, 39 (18.14%) were diagnosed with VTE during hospitalization. Results: Significant differences were found in D-dimer, ATIII and TEG parameters (maximum amplitude and coagulation index) between VTE-positive and VTE-negative patients (p < 0.05). Multivariate analysis revealed tumor node metastasis stage, concomitant infection, smoking history and D-dimer as independently associated with VTE. The constructed model and D-dimer areas under the curve were 0.809 and 0.764, respectively. Conclusion: TEG parameters were not significantly predictive indicators for VTE, with D-dimer remaining a key predictor.

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Early Online.

BACKGROUND: Long-haul flights have been associated with a two- to four-fold increased risk of aviation-related thrombosis (ART). Several studies have investigated the extent to which hypoxic hypobaric exposure, dehydration and prolonged immobilisation during air travel induce changes in haemostasis. OBJECTIVE: To investigate the role of high altitude as a risk factor for ART. METHODS: Healthy volunteers aged ≥18 years (N=40), without risk factors for venous thromboembolism, were exposed to an exacerbated altitude of 18 000 feet (5 486 m) for 1 hour. During the flight, the oxygen (O2) levels of the participants, who received supplemental O2, were measured by pulse oximetry and maintained at >92%. Venous blood and urine samples were collected prior to departure and immediately after flying in an unpressurised twin-engine airplane. D-dimer levels, thromboelastography (TEG) parameters, von Willebrand factor (VWF) activity and urine osmolality were measured. RESULTS: The participants were 19 men and 21 women, with a mean (standard deviation) age of 46 (14) years. A significant difference in D-dimer levels, VWF activity, urine osmolality and TEG parameters (reaction (R) time, kinetic (K) time and maximum amplitude (MA)) before and after the 1-hour flight was observed (p<0.001). Urine osmolality correlated positively with VWF activity levels (r=0.469; p<0.002). CONCLUSION: Air travel at high altitude induced a hypercoagulable state in healthy volunteers. Future research should focus on whether thromboprophylaxis can significantly obviate the activation of coagulation in response to high altitude.

ROTEM could be useful for lupus anticoagulant hypoprothrombinemia syndrome.

BACKGROUND: Lupus anticoagulant-hypoprothrombinemia syndrome (LAHPS) is a rare disease caused by acquired factor II (FII) deficiency and lupus anticoagulant. Patients with LAHPS typically present with thrombosis and bleeding. However, little information is available on the evaluation of coagulation potential in patients with LAHPS. We examined global coagulation potentials in patients with LAHPS during the clinical course in this study. METHODS: Coagulation potentials in two pediatric patients with LAHPS were assessed by measuring clotting time (CT) and clot formation time using Ca2+-triggered rotational thromboelastometry (ROTEM), CT and maximum coagulation velocity using clot waveform analysis (CWA), and lag time and peak thrombin using the thrombin generation assay (TGA). The day of admission was defined as day 0. RESULTS: In case 1, the bleeding symptoms disappeared by day 5. However, the TGA and CWA results were markedly lower than normal, although FII activity (FII:C) returned to within the normal range by day 14. In contrast, ROTEM revealed a recovery to near-normal levels (day 14). All coagulation parameters (day 80) were within normal ranges. In case 2, coagulation potential was severely depressed until day 12, although FII:C returned to normal levels. Bleeding symptoms disappeared on day 19, and the ROTEM data revealed that the parameters were close to the normal range. The coagulation parameters in all assays were normalized on day 75. CONCLUSIONS: Recovery of coagulation potential in patients with LAHPS was slower than the recovery of FII:C. Moreover, ROTEM appeared to be clinically useful for assessing coagulation potential in patients with LAHPS.

Thromboelastography-Guided versus Standard-of-Care or On-Demand Platelet Transfusion in Patients with Cirrhosis and Thrombocytopenia Undergoing Procedures: A Randomized Controlled Trial.

PURPOSE: To determine the rate of platelet transfusion in patients with cirrhosis and severe thrombocytopenia (platelet counts <50 × 109/L) undergoing high-risk invasive procedures when prescribed by thromboelastography (TEG) compared with empirical and on-demand transfusion strategies. MATERIALS AND METHODS: This was a single-center, single-blinded, randomized controlled trial. Patients with cirrhosis and severe thrombocytopenia undergoing high-risk invasive procedures were randomized into 3 groups: TEG group, transfusions based on TEG parameters; standard of care (SOC) group, 3 units of random donor platelets before procedure; and on-demand group, transfusions based on procedural adverse events/clinician's discretion. The primary outcome was periprocedural platelet transfusion in each arm. RESULTS: Eighty-seven patients were randomized (29 in each group) with no significant differences in demographics/coagulation profile/procedures. The median platelet count was 33 × 109/L (interquartile range, 26-43 × 109/L). Percutaneous liver biopsy was the most common procedure (46, 52.9%). Significantly lower number of patients in the TEG group received platelets (4 cases, 13.8%; 95% CI, 3.9-31.7) compared with SOC group (100%; 95% CI, 88.1-100; P < .001). Four patients in the on-demand group received platelets (13.8%; 95% CI, 3.9-31.7). Minor (World Health Organization [WHO] Grade 2) procedure-related bleeding occurred in 3 (10%; 95% CI, 2.2-27.4) patients in the TEG-guided transfusion group compared with 1 (3.4%; 95% CI, 0.1-17.8) patient each in the SOC and on-demand groups (P = .43), although the study was not powered for comparison of bleeding rates. No bleeding-related mortality was observed in any of the 3 groups. CONCLUSIONS: TEG-prescribed transfusion reduced prophylactic transfusions in patients with cirrhosis and severe thrombocytopenia undergoing high-risk invasive procedures. The study was not powered for comparison of bleeding rates.

Impact of introduction of a goal directed transfusion strategy in a patient blood management program: A single cardiac surgery centre experience.

BACKGROUND: The aim of this retrospective and observational study was to analyse the impact of the introduction of a goal directed transfusion (GDT) strategy based on a viscoelastic test (ROTEM®) and specific procoagulant products in a patient blood management (PBM) Program on blood product use and perioperative bleeding in a single cardiac surgery centre. STUDY DESIGN AND METHODS: Patient population underwent cardiac surgery from 2011 to 2021 was divided in two groups based on PBM protocol used (G#11-14, years 2011-2014, G#15-21, years 2015-2021) and compared for the following variables: intraoperative and postoperative transfusions of packed red blood cell and any procoagulant products, postoperative drain blood loss volume and rate of re-exploration surgery. The second program was defined after the introduction of a GDT protocol based on viscoelastic tests and specific procoagulant products. RESULTS: After the introduction of a GDT protocol, about 80% less amongst patients were transfused with fresh frozen plasma and any procoagulant product (p < 0.001 for both phases). Moreover, similar results were obtained with PRBC transfusions (p < 0.001) and drain blood loss volume (p = 0.006) in the postoperative phase. The main factors affecting the use of any procoagulant and PBRC transfusion in the multivariate logistic regression analysis was Group (2 versus 1, OR 0.207, p < 0.001) and preoperative haemoglobin (OR 0.728, p < 0.001), respectively. DISCUSSION: In our experience, a GDT strategy for the diagnosis and treatment of the coagulopathy in patients undergone cardiac surgery led to a significant reduction in bleeding and transfusion.

Prothrombin and activated partial thromboplastin times, thromboelastography, hematocrit, and platelet count in a feline hemorrhage/over-resuscitation model using lactated Ringer's solution or 6% tetrastarch 130/0.4.

OBJECTIVE: To describe and compare prothrombin time (PT), activated partial thromboplastin time (aPTT), thromboelastography (TEG), HCT, and platelet count measurements in a hemorrhage/over-resuscitation model. DESIGN: Randomized crossover study. SETTING: University teaching hospital. ANIMALS: Six cats. INTERVENTIONS: Anesthetized cats underwent 3 treatments at 2-month intervals. The treatments were as follows: NHR-no controlled hemorrhage and sham resuscitation; LRS-controlled hemorrhage and lactated Ringer's solution (LRS) for resuscitation; and Voluven-controlled hemorrhage and 6% tetrastarch 130/0.4 for resuscitation. The LRS and Voluven were administered at 60 and 20 mL/kg/h, respectively, for 120 minutes. Blood samples were drawn for PT, aPTT, TEG, HCT, and platelet count measurements at a healthy check (T - 7d), after controlled hemorrhage (T0), at 60 and 120 minutes of resuscitation (T60 and T120), and at 24 hours after completion of resuscitation (T24h). Data were analyzed using a general linear mixed model approach (significance was P < 0.05). MEASUREMENTS AND MAIN RESULTS: Total median blood loss (controlled hemorrhage and blood sampling from T0 to T120) at T120 was 11.4, 31.0, and 30.8 mL/kg for NHR, LRS, and Voluven, respectively. PT and aPTT during LRS and Voluven were prolonged at T60 and T120 compared to NHR (P < 0.001). On TEG, the reaction time, kinetic time, and alpha-angle were within reference intervals for cats at all time points in all treatments, while maximum amplitude was less than the reference interval (40 mm) at T0, T60, and T120 during Voluven and at T60 and T120 during LRS compared to NHR (both P < 0.001). The HCT and platelet count were significantly lower at T60 and T120 during LRS and Voluven compared to NHR (P < 0.001). CONCLUSIONS: Hypocoagulopathy was observed during hemorrhage and liberal fluid resuscitation. Prolongation of PT and aPPT and decreased clot strength may have been caused by hemodilution and platelet loss.

The Impact of Sex on Antiplatelet and Anticoagulant Thromboprophylaxis in Patients With Peripheral Artery Disease Post-revascularization.

OBJECTIVE: The aim of this prospective study was to (1) objectively quantify the impact of sex on platelet function in patients with peripheral artery disease (PAD) taking antiplatelet and anticoagulant medications and (2) to develop and test a personalized, iterative algorithm that personalizes thromboprophylaxis that incorporates platelet function testing. BACKGROUND: Women with PAD have worse outcomes as compared with their male counterparts despite having lower risk factors. This health disparity may be mitigated by personalizing thromboprophylaxis regimens. METHODS: Patients undergoing revascularization were enrolled. Serial thromboelastography (TEG) and TEG with platelet mapping (TEG-PM) were performed up to 6 months postoperatively to determine objective coagulation profiles. In a subset of patients, the Antiplatelet Coagulation Exactness (ACE) algorithm was implemented, where patients were iteratively evaluated with TEG and given antiplatelet medications to maintain platelet inhibition at >29%. Statistical analysis was performed using unpaired t test, analysis of variance, and Fisher exact test. RESULTS: One hundred eighty-one patients met the study criteria. Fifty-eight (32%) patients were females and 123 (68%) were males. In the Aspirin cohort, females showed significantly greater clot strength as maximum amplitude - arachidonic acid (MA AA ) and significantly lower platelet inhibition than males: (37.26 vs 32.38, P <0.01) and (52.95% vs 61.65%, P <0.05), respectively. In the Clopidogrel cohort, females showed higher Maximum Amplitude - Adenosine Diphosphate (MA ADP ) (42.58 vs 40.35, P = not significant [NS]) compared with males. Females on dual antiplatelet therapy had higher MA ADP (39.74 vs 35.07, P =NS) and lower platelet inhibition (45.25% vs 54.99%, P= NS) than males. The incidence of thrombosis of the revascularized segment, defined as thrombotic event, was objectively identified on an arterial duplex. Women showed significantly higher thrombotic events than men (22.95% vs 10.57%, P< 0.05) on the same medication. In our pilot study, implementation of the ACE algorithm led to a significant decrease in the thrombosis rate (3%), including nonthrombotic events for females, versus the historic thrombotic rate (22%) from our institution. CONCLUSIONS: Women with PAD exhibited higher platelet reactivity, clot strength, and reduced platelet inhibition in response to antiplatelet therapy. The use of the ACE algorithm to tailor antiplatelet medication in patients with PAD post-revascularization, resulted in a significant decrease in thrombotic event rates. This may serve as an opportune way to mitigate outcome sex-specific disparities caused by inadequate thromboprophylaxis in women.