Echocardiographic detection of transpulmonary bubble transit during coronavirus-2019 disease (COVID-19)

BACKGROUND: Transpulmonary bubble transit (TPBT) detected with contrast echocardiography is reported as a sign of intrapulmonary arteriovenous shunt. However, its pathological meaning is not clear during coronavirus-2019 disease (COVID-19) related acute respiratory distress syndrome (ARDS). Our aim was to determine the prevalence and clinical significance of TPBT detection during COVID-19 related ARDS. METHODS: We carried out a prospective observational study performed in a high complexity intensive care unit from Argentina. Patients with COVID-19 related ARDS underwent transthoracic echocardiography with saline contrast. Moderate-to-large TPBT was defined as right-to-left passage of at least twelve bubbles to left chambers after at least three cardiac cycles and complete opacification of the right atrium. RESULTS: We analyzed the results of 28 patients (24 men and 4 women). Seventy-five percent of the patients received invasive mechanical ventilation. Moderate-to-large TPBT was detected in 1 patient (3.5%). Among the 27 patients without significant TPBT, 23 had no TPBT and 4 had a minor TPBT. TPBT was not associated with invasive mechanical ventilation requirement (p = 0.5737) nor in-hospital mortality (p = 1). CONCLUSIONS: TPBT was not associated with severe hypoxemia or invasive mechanical ventilation requirement, although more studies are needed to further clarify its contributing role in COVID-19 hypoxemia.