COVID-19 and Deep Venous Thrombosis

Patients admitted to the Intensive Care Unit (ICU) are known to be at risk for
thrombo-embolic events. Virchow's triad describes the major risk factors in three categories:
venous stasis, vessel injury and activation of blood coagulation. A prolonged mechanical
ventilation together with the hemodynamic effects of this ventilation with a high positive
and expiratory pressure (PEEP), the presence of central venous catheters, the immobilization
of these patients and the presence of obesity or other comorbidities can attribute to the
occurrence of a deep venous thrombosis (DVT) in patients admitted at ICU. The incidence of
DVT during ICU stay has been reported between 5 and 15%.

On the 13th of March, the first COVID-19 patient was admitted at the ICU at the Jessa
Hospital. Within a few days, the admissions at our COVID-19 unit grew exponential. In these
difficult time, research concerning COVID-19 has been performed indicating the COVID-19 virus
induces a hyper-inflammatory state. It has been suggested that systemic inflammation induces
endothelial injury. This will activate the coagulation cascade and impair fibrinolysis with
disruption of endothelial barrier, and loss of physiologic antithrombotic factors which may
elevated the risk for DVTs significantly. Up to now, there is still no causal treatment for
COVID-19. The current management of COVID-19 is mainly supportive i.e. a prolonged
inflammatory status and a prolonged risk for VTE.

During the placement of a dialysis catheter in the femoral vein of one of the patients
admitted in the ICU for COVID-19 at our hospital, a large deep vein thrombosis (DVT) proximal
in both common femoral veins was noticed in a patient. Since there were no clinical signs of
DVT present in this patient, every patient at the ICU unit at that moment was screened on the
presence of DVTs. We found one or several deep vein thromboses in 8 out of 12 patients at 1
ICU unit. Since this was a unusual high incidence, we want to further investigate this
prevalence and evaluate possible causes of these DVTs.

The aim of this study is to investigate the prevalence and possible risk factors of the
occurrence of a DVT in 12 intubated and mechanically ventilated COVID-19 patients admitted to
the ICU at a single time point (29/03/2020).

The endpoint of this cross-sectional study is to investigate the prevalence and identify
possible risk factors of the occurrence of a DVT in these patients at the ICU.

These parameters are listed below and included parameters/values collected as a
standard-of-care in our hospital:

- Demographics: i.e age, gender

- Comorbidities: smoking, hypertension, diabetes, cardiovascular disease, respiratory
disease, malignancies, renal failure, liver failure, gastrointestinal disease,
neurological conditions, mental state, other

- Symptoms at the time of admission to ICU: i.e fever, body temperature, dyspnoea,
headache, diarrhea etc…

- Laboratory results of all standard parameters measured

- Treatment: antiviral agents, antibiotics, etc…

- Complications: shock, heart failure, sepsis, stroke, etc…

- Ventilation: method, PEEP, FiO2, ..

- Radiological findings: pneumonia, ground-glass opacity..