Transthoracic echocardiography of patients in prone position ventilation during the COVID-19 pandemic: an observational and retrospective study

Mechanical ventilation in prone position is a strategy that increases oxygenation and reduces mortality in severe ARDS. The hemodynamic and cardiovascular assessment of these patients is essential. Transthoracic echocardiography (TTE) is a widely used tool to assess hemodynamics in critical care, but the prone position is thought to limit adequate TTE views and goal-oriented measurements. The aim of this study is to show the feasibility of the hemodynamic assessment by transthoracic echocardiography during prone position ventilation (PPV). This is a retrospective, observational study, carried out in the intensive care unit (ICU) of a tertiary-care center in Buenos Aires, Argentina. We included all the adult patients admitted to the ICU between March 2020 and August 2021 who had a TTE examination in PPV due to ARDS. During the study period, we evaluated by TTE a total of 35 patients requiring PPV. The vast majority of the patients had COVID-19 pneumonia (91.4%). In 33 out of 35 (94.3%) cases, it was able to achieve an adequate apical four chamber view. We assessed qualitatively the systolic function of left ventricle (LV) and right ventricle (RV) in all of the successfully evaluated patients. We measured the RV basal diameter (94.3%), RV/LV ratio (77.1%), tricuspid annular plane systolic excursion (TAPSE) (91.4%), and septal mitral annular plane systolic excursion (MAPSE) (88.5%) in most of them. Also, we quantified the left ventricle outflow tract velocity time integral (LVOT VTI) in a large part (68.5%) of the examinations. Transthoracic echocardiography is a useful tool for the hemodynamic assessment of patients in prone position under mechanical ventilation.