Figure.

In vitro effect of hydroxyethyl starches (HESs) on blood samples of COVID-19 patients with hypofibrinolysis. (A) tissue plasminogen activator-thromboelastometry (tPA-TEM) curves obtained from a single patient with fibrinolysis resistance (WBp) and control patient (WBc). The green TEM-tPA curve represents a COVID-19 patient with a fibrinolysis resistance profile. The pink curve is the same patient with the addition of NaCl, and the blue curve is with the addition of HES. The red curve is a normal tPA-TEM control. HES seems to have an inhibitory effect on coagulation and an enhancing effect on fibrinolysis in tPA-resistant COVID-19 patients. (B) Comparison of the amplitude at 5 minutes (A5) and the amplitude of lysis at 30 minutes (Ly30) in the presence of HES and saline in tPA-resistant COVID-19 patients. Green represents patients with resistance to fibrinolysis, blue represents the same patients with HES treatment, and pink represents the same patients treated with NaCl. Clot firmness at 5 minutes was decreased in presence of HES compared with saline and untreated samples. Comparable differences were obtained at 30 minutes. (C) Comparison of endogenous thrombin potential, peak thrombin, and time to peak. No statistically significant difference was observed for all TGA parameters studied. (D) Comparison of fibrin filament diameters in the presence of HES and NaCl in non-COVID-19 and COVID-19 patients. In the presence of HES, fibrin fibers of COVID-19 patients were thicker compared with saline-treated samples. Similar effect of HES on fibrin was also observed in control subjects. (E) Electronic microscopy images obtained from a COVID-19 patient and a non-COVID-19 patient. With HES, fibrin fibers seem to be thicker compared with saline.