Echocardiography
Echocardiography assessment was performed in all patients within 48 h of ICU admission by the same echocardiographer using a commercially available system (Vivid E9, GE, Inc.) equipped with a 2.5-4MHz transducer (M5S probe). All patients were examined in a calm or sedated state. All echocardiographic parameters were evaluated according to American Society of Echocardiography (ASE) guidelines [12].