Influence of hyperbaric oxygen therapy on thrombus formation ability in humans.

Background: Hyperbaric oxygen (HBO2) therapy was introduced nearly 300 years ago. However, its effect on thrombus formation is unclear. This may be because platelet and coagulation functions are unstable, yielding variable results; hence, accurate measurement is difficult. Our study aimed to analyze changes in thrombus formation before and after HBO2 therapy by using a total thrombus formation analysis system (TTAS). Methods: Six patients were prescribed HBO2 therapy for skin and soft tissue ulcers, and necrotic fasciitis. Blood samples were collected immediately before and after treatment. Then samples were put into a reservoir that connected to AR-chip to assess changes in the thrombus formation ability of both platelets and coagulation factors. We examined the differences in the thrombus formation ability using T-TAS. Time until the onset of white thrombus formation (T10) and complete occlusion of the capillary (T80) were analyzed by a two-way repeated measure analysis of variance (ANOVA). Results: The duration to pressure increase of samples after HBO2 therapy was longer than the duration before HBO2 therapy (p<0.05). This suggests decreased clot adhesiveness to the inner surface of the simulated blood vessel and reduced clot formation ability. Conclusions: The results for T10 and T80 suggest that HBO2 therapy reduced thrombus formation ability in the enrolled patients. We believe that T-TAS is a promising method to predict the efficacy of HBO2 therapy.

Coagulation Influencing Liberation from Respiratory Support in Patients with Coronavirus Disease 2019: A Retrospective, Observational Study.

BACKGROUND: Patients with coronavirus disease 2019 (COVID-19) occasionally develop respiratory failure and coagulopathy. We aimed to determine whether coagulation abnormalities at admission and during the course of hospitalization can predict the liberation from respiratory support in critically ill patients with COVID-19 by combining the results of rotational thromboelastometry (ROTEM) with standard laboratory tests. METHODS: This single-center, retrospective, observational study included 31 consecutive adult patients with COVID-19 who were admitted to the intensive care unit (ICU) and who required respiratory support between April 2021 and August 2021. We divided the patients into two groups according to the liberation from respiratory support and analyzed the differences between the groups. RESULTS: There were 20 patients in the liberation group and 11 in the non-liberation group. There were no significant differences in the overt disseminated intravascular coagulation scores or abnormal counts in the ROTEM parameters at admission between groups, although there was a significant difference in the highest score in the ICU. The Sequential Organ Failure Assessment and sepsis-induced coagulopathy scores were significantly different between both groups at admission and at the time when the highest values were reported during the ICU stay. CONCLUSIONS: High sepsis-induced coagulopathy scores at admission to the ICU were found to be useful predictors of difficulties in the liberation from respiratory support in patients with severe COVID-19. However, increased overt disseminated intravascular coagulation scores and abnormal counts in the ROTEM parameters during the ICU stay were associated with difficulties in the liberation from respiratory support.

Investigation of predictors of bleeding complications in COVID-19 using rotational thromboelastometry (ROTEMⓇ): A retrospective study.

Background: Hemorrhagic complications in patients with coronavirus 19 disease (COVID-19) are infrequent but associated with a prognosis. This study aimed to elucidate the risk factors for bleeding complications in patients with COVID-19 using rotational thromboelastometry (ROTEM) parameters and blood tests performed at admission. Methods: In total, 31 patients with severe COVID-19 treated intensively at Saga University Hospital were included in this study. Patients were divided into two groups according to the presence or absence of hemorrhagic complications. Results from the blood tests performed at admission and during hospitalization, and ROTEM values acquired upon admission, were compared between the two groups. Results: There were significant differences in ROTEM values upon admission between the bleeding and non-bleeding groups. Receiver operating curve analysis showed that the area under the curve for prothrombin time international normalized ratio (PT-INR) and extrinsically-activated test with tissue factor (EXTEM) amplitude at 10 min (A10) were 0.82 (0.52-0.92) and 0.81 (0.58-0.93), respectively. Logistic regression analysis with PT-INR and EXTEM A10 as factors calculated an odds ratio of 1.94 (1.04-3.62) and EXTEM A10 0.86 (0.71-1.05) for bleeding complications occurrence. Conclusion: ROTEM may be a sensitive predictor for bleeding complications in patients with COVID-19.

Usefulness of a medical interview support application for residents: A pilot study.

To conduct an appropriate medical interview, education and clinical experience are necessary. The usefulness of computer-based medical diagnostic support systems has been reported in medical interviewing. However, only a few reports have actually applied these systems and noted changes in the quality of the medical interview of residents. We aimed to examine how the use of a medical interview support application changes the medical interviews of residents. The study was conducted on 15 residents (with less than two years post-graduation) and ran from November 2020 to March 2021. Faculty members played the role of simulated patients in 20 cases, and the residents conducted the medical interviews. In 10 of the 20 cases, a medical interview support application was used. After the interview, the residents were asked to list up to 10 differential diseases; the interview was considered appropriate if it included the disease portrayed by the simulated patient. Furthermore, the duration of the medical interview, the number of questions asked, and changes in stress parameters were evaluated. The use of a medical interview support application increased the percentage of appropriate medical interviews. Considering the frequency, the use of a medical interview support application increased the rate of appropriate medical interviews in the rare disease group, as well as the number of questions and duration of the interviews. No stress reduction was observed. The medical interview support application may be a useful tool in identifying appropriate differential diseases during medical interviews by residents.

Influence of high-dose antithrombin on platelet function and blood coagulation.

AIM: In healthy adults, there are sufficient amounts of antithrombin in the blood to regulate thrombin. However, the effects of high concentrations of antithrombin on dose-dependent anticoagulation and platelet function have not been reported. In this study, we assessed platelet function and blood coagulation following high-dose antithrombin supplementation in vitro. METHODS: Blood samples were collected from 10 healthy volunteers, and samples with different antithrombin concentrations were prepared by adding an antithrombin agent (Neuart). Blood coagulation was assessed by the Thrombus-Formation Analysis System (T-TAS) and Rotational Thromboelastometry (ROTEM) using whole blood samples. RESULTS: The data obtained by the platelet chip, exclusively representing platelet function, revealed that the onset of thrombus formation was significantly delayed in a dose-dependent manner (100%-200%, P = 0.021; 100%-500%, P = 0.011; 200%-500%, P = 0.047). In measurements using the atheroma chip, which enables assessment of blood coagulation, the thrombus formation ability was found to be reduced (100%-200%, P = 0.022; 100%-500%, P = 0.05). In the ROTEM measurements, clotting time was prolonged in a dose-dependent manner (100%-200%: P = 0.203, 200%-500%: P = 0.005, 500%-1000%: P = 0.022), except when comparing with 100% and 200%. Although antithrombin is reportedly saturated in healthy blood, its anticoagulant ability appears to be enhanced depending on its concentration. Furthermore, data obtained from the platelet chip showed that antithrombin might reduce platelet function. CONCLUSIONS: Antithrombin suppressed platelet function and blood coagulation in a dose-dependent manner.

Development of a delirium predictive model for adult trauma patients in an emergency and critical care center: a retrospective study.

BACKGROUND: Delirium has been shown to prolong the length of intensive care unit stay, hospitalization, and duration of ventilatory control, in addition to increasing the use of sedatives and increasing the medical costs. Although there have been a number of reports referring to risk factors for the development of delirium, no model has been developed to predict delirium in trauma patients at the time of admission. This study aimed to create a scoring system that predicts delirium in trauma patients. METHODS: In this single-center, retrospective, observational study, trauma patients aged 18 years and older requiring hospitalization more than 48 hours were included and divided into the development and validation cohorts. Univariate analysis was performed in the development cohort to identify factors significantly associated with prediction of delirium. The final scoring system for predicting delirium was developed using multivariate analysis and internal validation was performed. RESULTS: Of the 308 patients in the development cohort, 91 developed delirium. Clinical Frailty Score, fibrin/fibrinogen degradation products, low body mass index, lactate level, and Glasgow Coma Scale score were independently associated with the development of delirium. We developed a scoring system using these factors and calculated the delirium predictive score, which had an area under the curve of 0.85. In the validation cohort, 46 of 206 patients developed delirium. The area under the curve for the validation cohort was 0.86, and the calibration plot analysis revealed the scoring system was well calibrated in the validation cohort. DISCUSSION: This scoring system for predicting delirium in trauma patients consists of only five risk factors. Delirium prediction at the time of admission may be useful in clinical practice. LEVEL OF EVIDENCE: Prognostic and epidemiological, level III.