ABSTRACT
BACKGROUND: SARS-CoV-2 infections are suspected to trigger the coagulation system through various pathways leading to a high incidence of thromboembolic complications, hypercoagulation and impaired fibrinolytic capacity were previously identified as potentially mechanisms. A reliable diagnostic tool for detecting both is still under discussion. This retrospective study is aimed to examine the prognostic relevance of early viscoelastic testing compared to conventional laboratory tests in COVID-19 patients with acute respiratory distress syndrome (ARDS). METHODS: All mechanically ventilated patients with COVID-19 related ARDS treated in our intensive care unit (ICU) between January and March 2021 were included in this study. Viscoelastic testing (VET) was performed using the ClotPro® system after admission to our ICU. Prevalence of thromboembolic events was observed by standardized screening for venous and pulmonary thromboembolism using complete compression ultrasound and thoracic computed tomography pulmonary angiography at ICU admission, respectively. We examined associations between the severity of ARDS at admission to our ICU, in-hospital mortality and the incidence of thromboembolic events comparing conventional laboratory analysis and VET. ECMO related coagulopathy was investigated in a subgroup analysis. The data were analyzed using the Mann-Whitney U test. RESULTS: Of 55 patients enrolled in this study, 22 patients required treatment with ECMO. Thromboembolic complications occurred in 51% of all patients. Overall hospital mortality was 55%. In patients with thromboembolic complications, signs of reduced fibrinolytic capacity could be detected in the TPA assay with prolonged lysis time, median 460 s (IQR 350-560) vs 359 s (IQR 287-521, p = 0.073). Patients with moderate to severe ARDS at admission to our ICU showed increased maximum clot firmness as a sign of hypercoagulation in the EX-test (70 vs 67 mm, p < 0.05), FIB-test (35 vs 24 mm, p < 0.05) and TPA-test (52 vs 36 mm, p < 0.05) as well as higher values of inflammatory markers (CRP, PCT and IL6). ECMO patients suffered more frequently from bleeding complications (32% vs 15%). CONCLUSION: Although, the predictive value for thromboembolic complications or mortality seems limited, point-of-care viscoelastic coagulation testing might be useful in detecting hypercoagulable states and impaired fibrinolysis in critically ill COVID-19 ARDS patients and could be helpful in identifying patients with a potentially very severe course of the disease.
ABSTRACT
The fingertip somatotopy in BA1 and BA3b of monkeys exhibits characteristic differences with a more discrete separation of the body parts in BA3b and a continuous orientation column-like structure in BA1. We present evidence for similar differences in the human somatotopy using BOLD fMRI for the investigations. Though the variability between the individual maps was large, we found a group-wide somatotopic representation in BA3b and BA1. The variability due to anatomical differences was small in our sample. This was demonstrated by comparing exact shortest distances in the individual brains and after nonlinear normalization to the group space template, for the removal of the individual anatomical variability. Distance mapping along Dijkstra paths was found to be a valid approximation to exact shortest paths only in the individual brains. The degree of fine-scale detail mapping was improved if valid surface distances instead of 3D Euclidean distances were applied. A further improvement was achieved by mapping the distances between all neighboring fingertips instead of only the outer fingertips. Taking into account all optimizations we found mirror symmetry of the somatotopy with respect to the interhemispheric gap.
