Right ventricle dilation as a prognostic factor in refractory acute respiratory distress syndrome requiring veno-venous extracorporeal membrane oxygenation.

BACKGROUND

The aim of this study was to assess the incidence and prognostic role of echocardiographic abnormalities in consecutive patients with refractory acute respiratory distress syndrome (ARDS) before veno-venous extracorporeal membrane oxygenation (VV-ECMO).

METHODS

In this study 74 consecutive patients with refractory ARDS underwent echocardiography (transthoracic, transesophageal or both, according to the best acoustic window). Baseline characteristics were collected for all patients and the simplified acute physiology score was calculated. At echocardiography the following parameters were considered: left ventricle (LV) ejection fraction, right ventricle (RV) size and function (by means of tricuspid annular plane excursion [TAPSE]) and systolic pulmonary arterial pressure.

RESULTS

At echocardiography, 25 patients showed normal findings (33.8%), 32 patients exhibited isolated pulmonary hypertension (43.2%) and the remaining 17 patients showed RV dilation and pulmonary hypertension (23%). A reduced LVEF (<50%) was observed in 14 patients (18.9%), while RV dysfunction (as indicated by TAPSE<16 mm) was documented in 21 patients (28.4%). The in-Intensive Care Unit [ICU] mortality rate was 41.8%. At stepwise regression analysis the following variables were independent predictor for in-ICU mortality (when adjusted for TAPSE<16 mm): RV end diastolic area/LV end diastolic area (OR 0.21, 95%CI 0.062-0.709, P=0.012), Body Mass Index (BMI) (OR 0.87, 95%CI 0.802-0.958, P=0.004) CONCLUSIONS: In consecutive patients with refractory ARDS, echocardiographic alterations were common, mainly represented by systolic pulmonary hypertension associated or not with RV dilatation. Moreover, RV dilatation and BMI were independent predictors of in-ICU mortality. On clinical grounds, our findings strongly suggest that echocardiography helps to risk stratifying patients with refractory ARDS requiring VV-ECMO.