Venous Thromboembolism Is an Independent Risk for Higher Morbidity and Mortality in Critically Ill Patients with Respiratory Viral Infection

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Introduction/Rationale There are many established risk factors for venous thromboembolism (VTE) such as trauma, immobilization and malignancy. However, it is unclear whether infection with viral agents such as influenza also predisposes individuals to VTE. To date, there is very little literature regarding this. In fact, there have been no studies exploring association of VTE in patients with viral infection other than influenza infections.

Methods This retrospective study analyzed 226 adult patients with microbiologically proven respiratory viral illness admitted to the intensive care unit from 2011 to 2016. Adult patients (18 to 90 years old) with positive influenza or respiratory viral panel were included. All patients received VTE prophylaxis during their hospitalization. Chart reviews were performed. VTE locations included deep venous thrombosis (DVT) or superficial venous thrombosis (SVT) in the upper/lower extremities as well as pulmonary embolism (PE).

Results The overall prevalence of VTE (including DVT, SVT and PE) in this cohort was 34.45% (79/226). 16.37% of patients with influenza infection and 18.58% of patients with non-influenza infection were found to have VTE. Length of stay in hospital was significantly higher for patient with VTE compared to patient without. (20.70 vs 13.37, p = 0.0001). Overall mortality at discharge was 25.66%. Patient with VTE had higher mortality compared to patients without VTE (36.7% vs. 19.7%, p = 0.005). During multivariate logistic regression VTE was found to be statistically significant (p = 0.015) independent risk factor associated with mortality along with DM, active cancer and age.

Conclusion This study demonstrates the importance of recognizing prevalence of VTE in patients admitted for respiratory viral infection (influenza and non-influenza). With VTE there is a significant impact on mortality and therefore early assessment for VTE is mandatory.