Thoracic Fluid Content by Bioimpedance-based Starling System

The Starling system is a completely non-invasive hemodynamic monitoring technique. It is able to measure the thoracic fluid content (TFC). The TFC is supposed to reflect the total content of fluid in the thorax. Thus, TFC may include two of the variables that are commonly used for hemodynamic monitoring: the extravascular lung water (EVLW), and the global end-diastolic volume (GEDV). However, whether the TFC actually reflects GEDV and EVLW has not been clearly established. The objective of the study is to establish the determinants of TFC among hemodynamic variables including EVLW and GEDV.

Inclusion Criteria:Age ≥ 18 y.o.Hospitalization in an ICUMonitoring by transpulmonary thermodilution already in placeDecision by clinicians in charge to perform volume expansion by saline or fluid removal by diuretics infusion and/or ultrafiltration ("Fluid" group)Or presence of Acute Respiratory Distress Syndrome according to the Berlin definition ("ARDS" group)Exclusion Criteria:Refusal to join the studyIn "Fluid" group, circulatory failure whose treatment cannot be postponed for ≥5 minutes (time required for the installation of Starling system).Impossibility to paste bioreactance electrodes properly in the skin of the thorax.