[Hydroxyethyl starch]

In vitro effect of hydroxyethyl starch on COVID-19 patients-associated hypofibrinolytic state

Background

Despite systematic thromboprophylaxis, 30% of the COVID-19 patients in intensive care units develop thrombosis. This occurrence is associated with a hypofibrinolytic state measured by thromboelastometry when adding tissue plasminogen activator (tPA) to citrated whole blood for a further run for EXTEM (ROTEM).

Objectives

Because hydroxyethyl starches (HESs) affect fibrin polymerization, we have assessed its potential effect on in vitro tPA-induced fibrinolysis.

Methods

Fifteen successive COVID-19 patients from the local intensive care units were selected for tPA resistance occurrence. HES was added to whole blood samples with proportion similar to the pharmacologic recommendations. Samples were run for EXTEM on a ROTEM delta device after further addition of tPA. Paired controls were whole blood samples with the same volume of saline added. To assess the impact of HES on coagulation, thrombin generation was measured in 10 COVID-19 patients in the presence of either HES or saline; then, the clots obtained were used to generate electron microscope images.

Results

Clot firmness at 5 minutes and the lysis index at 30 minutes were decreased in presence of HES compared with saline (Wilcoxon test, P < .01 for HES vs saline and HES vs untreated). However, no statistically significant difference was observed for all thrombin generation assay parameters studied (endogenous thrombin potential, peak thrombin, and time to peak). With HES, fibrin fibers of either COVID-19 patients or control subjects were thicker than those of saline-treated samples.

Conclusion

These results highlight that HES increased apparent in vitro tPA-induced fibrinolysis in case of severe COVID-19 disease. Use of this plasma volume expander may translate as a potential help against COVID-19-induced thrombosis occurrence.

[The damage control resuscitation concept]

OBJECTIVE

Damage control is a strategy of care for bleeding trauma patients, involving minimal rescue surgery associated to perioperative resuscitation. The purpose of this review is to draw up a statement on current knowledge available on damage control.

DATA SOURCES

References were obtained from recent review articles, personal files, and Medline database research of English and French publications. All categories of articles on this topic have been selected.

DATA SYNTHESIS

Historical damage control surgery, that consist of abbreviated laparotomy with second-look after resuscitation, is now included in a wider concept called "damage control resuscitation", addressing the lethal triad (coagulopathy, hypothermia and acidosis) at an early phase. Care is focused on coagulopathy prevention. Early resuscitation, or damage control ground zero, has been improved: aggressive management of hypothermia, bleeding control techniques, permissive hypotension concept and early use of vasopressors. Transfusion practices also have evolved: early platelets and coagulation factors administration, use of hemostatic agents like recombinant FVIIa, whole blood transfusion, denote the damage control hematology. Progress in surgical practices and development of arteriographic techniques lead to wider indications of damage control strategy.