Right Ventriculo-Arterial Coupling During Fluid Loading in ICU Patients

Inclusion criteria: * Critically ill hospitalized patients * Age ≥ 18 years * Patients undergoing fluid loading at the discretion of the attending physician, following prediction of fluid responsiveness using any recommended maneuver or dynamic parameter, in the setting of acute circulatory failure requiring vasopressor support and/or mean arterial pressure \< 65 mmHg (or a decrease of ≥ 30 mmHg from baseline in patients with chronic hypertension), and/or other signs of hemodynamic instability (tachycardia, mottling, oliguria, hyperlactatemia) * Affiliated with a national health insurance system Exclusion criteria : * Formal refusal from the patient or legally representative after information * Patients transferred from another intensive care unit * Pregnant or postpartum patients * Acute respiratory distress (defined as respiratory rate ≥ 35 breaths/min and/or signs of increased work of breathing) * Ongoing acute coronary syndrome * Acute or pulmonale (defined by right ventricular dilation associated with paradoxical septal motion related to an abrupt increase in right ventricular afterload) * Primary pulmonary arterial hypertension * Intra-abdominal hypertension (intravesical pressure \> 15 mmHg) * Poor echogenicity precluding adequate echocardiographic assessment of the right ventricle * Severe valvular heart disease or early postoperative period following valvular surgery