Severity of acute respiratory distress syndrome and echocardiographic findings in clinical practice-an echocardiographic pilot study.

BACKGROUNDS: The still high poor outcome of ARDS may be more consequence of circulatory failure than hypoxemia per se. For patients with circulatory failure and ARDS, hemodynamic instability is directly related to ARDS following pulmonary circulation dysfunction and its consequence - right ventricular (RV) dysfunction.

OBJECTIVES

We hypothesize that in the era of protective ventilation, echocardiographic abnormalities did not parallel ARDS severity, defined by the degree of hypoxemia.

METHODS

We included 63 consecutively identified mechanically ventilated ARDS patients (1st January 2015 to 31th December 2016). All had echocardiography performed routinely within the first 12 h after ICU admission.

RESULTS

The analysis included 110 exams. Twenty-eight patients had severe ARDS (28/63, 44.4%), 27 had moderate ARDS (27/63, 42.1%) and 8 mild ARDS (8/63, 12.7%).There was no difference in echocardiographic findings between mild-moderate and severe ARDS. At Pearson's linear regression analysis, TAPSE was directly correlated with LVEF (r = 0.22, p = 0.021) and inversely with sPAP (r = -0.37, p < 0.001). Systolic pulmonary arterial pressure (sPAP) showed a direct correlation with pCO2 (r = 0.30, p = 0.002) and an inverse one with pH (r = -0.35, p < 0.001) and TAPSE (r =-0.35, p < 0.001).

CONCLUSIONS

Among patients with ARDS, the severity of disease (as indicated by pO2) does not translate into specific cardiac abnormalities, detected by echocardiography. However, RV function (as indicated by TAPSE) is inversely related to pCO2 and to sPAP (which therefore may be underestimated in presence ofRV dysfunction). Our data strongly suggest that in mechanically ventilated ARDS, the interpretation of echo findings should consider also pCO2 values.