Comparison of two point of care whole blood coagulation analysis devices and conventional coagulation tests as a predicting tool of perioperative bleeding in adult cardiac surgery-a pilot prospective observational study in Japan

Platelet Function Testing Using Sonoclot and TEG6s as a Platelet Transfusion Prediction Tool in Open Heart Surgery

Introduction The point-of-care test (POCT) is useful for blood coagulation management during cardiovascular surgery. Although thromboelastography (TEG6s) has been reported to have targeted benefits for blood transfusion in cardiac surgery, Sonoclot analysis has not yet been fully validated. In this study, we evaluated the accuracy of Sonoclot, especially platelet function (PF) as a platelet concentrate (PC) transfusion parameter, compared to TEG6s in cardiovascular surgery. Methods This single-center, prospective, randomised trial was conducted at a university hospital. Forty-two adult patients who underwent elective cardiac surgery requiring cardiopulmonary bypass were included in this study between 2017 and 2021. The participants were randomly assigned to the Sonoclot (S) or Sonoclot and TEG6s (ST) groups. The amount of intraoperative PC was determined according to the POCT parameter values at the time of protamine administration. In addition, we investigated the correlation between PF parameters of POCT and platelet count at the end of surgery. Results There was no statistically significant difference in the intraoperative PC volume between the two groups. The Sonoclot PF parameter, PF, was moderately correlated with platelet count at the end of surgery (r=0.5449, p=0.009), and the TEG6s PF parameter showed a strong correlation with platelet count at the end of surgery (r=0.7744, p<0.001). Conclusion There was no statistically significant difference in platelet transfusion volume between the Sonoclot and TEG6s in this study. The correlation between the PF of the Sonoclot and platelet count was moderate. This study suggests that PF of Sonoclot may be a potentiating indicator of PF.

Thromboelastography in the Perioperative Period: A Literature Review

Assessing coagulation status is essential for prompt intervention to reduce morbidity and mortality related to bleeding and thrombotic complications during the perioperative period. Traditional coagulation tests such as platelet count, activated partial thromboplastin time (aPTT), prothrombin time (PT), international normalized ratio (INR), and activated clotting time (ACT) provide only static evaluation. These tests are not designed for assessment of dynamically changing coagulation conditions during the perioperative time. However, viscoelastic coagulation testing such as thromboelastography (TEG) produces a rapid numerical and graphical representation that helps to detect and direct targeted hemostatic therapy. Searching the literature through PubMed, Medline, Ovid, CINAHL, and ClinicalTrials.gov we retrieved 210 studies, which represent the use of TEG in the perioperative period. The included studies were categorized under various settings such as trauma, obstetrics, orthopedics, intensive care unit (ICU), cardiovascular, transplant, and miscellaneous scenarios. TEG showed promising results in trauma surgeries in predicting mortality, hypercoagulability, and bleeding even when it was compared to conventional methods. TEG was also useful in monitoring anticoagulant therapy in orthopedic and obstetric surgeries; however, its role in predicting thrombotic events, hypercoagulability, or complications was questionable. In ICU patients, it showed promising results, especially in the prediction or improvement of sepsis, coagulopathy, thrombotic events, ICU duration, hospital stay, and ventilator duration. TEG parameters effectively predicted hypercoagulation in transplant surgeries. Regarding cardiovascular surgeries, they were effective in the prediction of the need for blood products, coagulopathy, thrombotic events, and monitoring anticoagulation therapy. More randomized clinical trials comparing TEG parameters with standardized tools are needed to produce robust results to standardize its use in different perioperative settings.

Are Viscoelastometric Assays of Old Generation Ready for Disposal? Comment on Volod et al. Viscoelastic Hemostatic Assays: A Primer on Legacy and New Generation Devices. J. Clin. Med. 2022, 11, 860

With the advent of new viscoelastometric hemostatic assay (VHA) devices, with ready-to-use cartridge reagents allowing for their use by people without special laboratory skills, the appreciation of the actual clinical value of VHAs in settings such as severe trauma, post-partum hemorrhage, cardiac surgery and liver transplantation still needs to be fully validated. While two of the newest versions remain based on a 'cup and pin' system (ROTEM^® sigma, ClotPro^®), two other new devices (TEG^® 6s, Quantra^®) rely on very different technologies: clotting blood is no longer in contact with the probe and challenged by oscillation of one of the components but explored with ultrasound exposure. A systematic literature search (including Sonoclot^®) retrieved 20 observational studies (19 prospective). Most studies pointed to imperfect agreements, highlighting the non-interchangeability of devices. Only a few studies, often with a limited number of patients enrolled, used a clinical outcome. No study compared VHA results with conventional laboratory assays obtained through a rapid tests panel. Clinical evidence of the utility of the new VHAs largely remains to be proven through randomized clinical trials, with clinically relevant outcomes, and compared to rapid panel hemostasis testing. The availability of new, improved VHA devices provides an impetus and an opportunity to do so.

Clinical Application of Thromboelastography in Patients With Severe Fever With Thrombocytopenia Syndrome

AIM

To investigate the clinical application of thromboelastography (TEG) in severe fever with thrombocytopenia syndrome (SFTS).

METHODS

One hundred and fifty-seven patients with SFTS were included in the study. The participants were distributed into 3 groups; A, B, and C. And 103 patients in group A met the clinical criteria as they exhibited slight liver and kidney dysfunction. Group B consisted of 54 patients with SFTS who were critically ill while group C was a healthy control group with 58 participants.

RESULTS

Patients with SFTS exhibited lower coagulation than the healthy participants. Group B patients exhibited significantly lower coagulation compared to group A. There was no significant difference in platelet count and fibrinogen content between patients in group A and group B, but platelet aggregation function and fibrinogen activity were significantly lower in group B patients.

CONCLUSION

Our results suggest that it is risky to solely rely on platelet count and the fibrinogen in SFTS. Monitoring of TEG and other coagulation indexes should be emphasized.

High-dose intravenous iron supplementation after preoperative autologous blood donation is useful to prevent post-donation/preoperative anemia

To estimate the effectiveness of high-dose intravenous (IV) iron supplementation for iron deficiency anemia after preoperative autologous blood donation (PAD), 155 donors who visited the donation office of the University of Tokyo Hospital from December 2020 to June 2021 and showed suspected post-donation anemia were analyzed. The participants were treated with high-dose intravenous (IV) iron supplementation (high-dose group, n = 30) or a combination of low-dose IV iron and oral iron supplementation (low-dose group, n = 125). The preoperative hemoglobin (Hb) and Hb decreasing ratios during PAD (ΔHb) were compared between the two groups. Multivariate linear regression analyses were also performed to identify the confounding factors associated with preoperative Hb and ΔHb as well as high-dose IV iron supplementation. Preoperative Hb level was slightly higher in the high-dose group than in the low-dose group (12.1 ± 1.1 vs. 11.9 ± 1.1 g/dL, p = 0.27). ΔHb was significantly higher in the high-dose group than in the low-dose group (3.7 % ± 8.8 % vs. 7.7 % ± 6.5 %, p = 0.011). On the multivariate linear regression analyses, high-dose IV iron supplementation was significantly associated with higher preoperative Hb and lower ΔHb levels (p = 0.021 and 0.017, respectively) as well as the donation available period (period from the first visit to the donation office to the operation) and administration of erythropoiesis-stimulating agents. High-dose IV iron supplementation after PAD will be useful in the treatment of post-donation anemia.

Establishment of Normal Range for Thromboelastography in Healthy Middle-Aged and Elderly People of Weihai in China

TEG can monitor the dynamic changes of blood clot formation and lysis by activating the coagulation system of a small sample of whole blood in vitro. The parameters can reflect the level of coagulation factors, the function of fibrinogen and platelet, and the presence or absence of hyperfibrinolysis. At present, the normal reference range of the parameters of TEG is mainly based on the reference values established by the Western population. Due to the differences in the distribution of ethnic groups, many countries have established their reference ranges for healthy populations. In China, some scholars have tried to establish the corresponding TEG reference range according to the characteristics of the population in different regions. This study tried to establish the reference range for thromboelastography in healthy middle-aged and elderly people of Weihai in China and compare it with the reference range provided by the manufacturer. The fasting venous blood of 454 healthy middle-aged and elderly people was collected, including 239 males and 215 females. The thromboelastography TEG-5000 was used to measure the reaction time (R), coagulation formation time (K), coagulation angle (Angle), and maximum amplitude (MA). The reference range of TEG parameters of middle-aged and elderly healthy males was R: 4.38–8.27 min, K: 1.44–2.82 min, Angle: 48.53–72.17 deg, and MA: 51.95–72.02 mm; respectively, in the females, the normal value was R: 3.43–7.40 min, K: 1.07–2.53 min, Angle: 48.22–77.22 deg, and MA: 53.10–74.58 mm; The difference of R, K, Angle, and MA between the male group and the female group was statistically significant (P < 0.05); In this study, if we use the reference range established by the manufacturer, the R specificity for males was 91.6%, K specificity was 98.7%, Angle specificity was 85.8%, and MA specificity was 93.7%; the range for females was 68.4%, 99.5%, 75.8%, and 87.4%, respectively. There are statistically significant differences between R, K, Angle, and MA in middle-aged and elderly healthy women and men. It is necessary to establish a TEG reference range for healthy females and males.

Clinical Validation of Global Coagulation Tests to Guide Blood Component Transfusions in Cirrhosis and ACLF

BACKGROUND AND AIMS

Patients with cirrhosis and acute-on-chronic liver failure (ACLF) may have bleeding complications and need for invasive procedures. Point-of-care (POC) coagulation tests like thromboelastography (TEG) and Sonoclot may be better for guiding patient management than the standard coagulation tests (SCTs), like prothrombin time, platelet count and international normalized ratio.

METHODS

We prospectively compared and validated the POC tests and SCTs in 70 persons with ACLF and 72 persons with decompensated cirrhosis who had clinical bleeding and checked for episodes of re-bleeding and transfusion requirements. We assessed pre-procedure requirement of blood components when correction was done based on an SCT or POC strategy.

RESULTS

Episodes of bleeding were seen in 45% and 28% of ACLF and cirrhosis patient, respectively (p=0.036), with the major site of bleeding being gastrointestinal (31% and 16%, respectively). Platelet counts correlated with TEG-maximum amplitude in cirrhosis (p=0.045) and prothrombin time correlated positively with TEG-reaction (R) time (p=0.032), TEG-Clot kinetics (K) time (p=0.042), Son-activated clotting time (p=0.038) and negatively with clot rate (p=0.043) in ACLF, making these correctable target variables in POC transfusion algorithms. Of 223 procedures, transfusion of fresh frozen plasma and platelet concentrate was reduced by 25% (p=0.035) and 20.8% (p=0.045) by using a POC strategy in 76 patients. Correction of deranged Son-activated clotting time and TEG-reaction time was noted in 68% and 72% after 24 h of fresh frozen plasma transfusion in ACLF and 85% and 80% in cirrhosis, respectively.

CONCLUSIONS

Our study clinically validates that POC tests can better detect coagulation defects and transfusion thresholds in ACLF and cirrhosis, whereas use of conventional tests appear to be less suitable in patients with clinical bleeding.

TRIAL REGISTRATION

NCT04332484.