Discontinuous Echocardiographic Subcostal Cardiac Output Measurement

Discontinuous Echocardiographic Subcostal Cardiac Output Measurement by the Right Ventricular Outflow Tract in Critical Care

Cardiac output (CO) monitoring is recommended for the most serious and multiple-failure patients in critical care and allows the diagnosis of acute circulatory failure as well as its etiology and also allows the monitoring of treatments. However, although allowing an adaptation of hemodynamic treatments and being integrated into a therapeutic personalization approach in situations of acute circulatory failure, the measurement of CO is conditioned by the availability of devices, by their sometimes problematic invasiveness, as well as their cost. In addition, the discontinuous measurement of CO by echocardiography is made difficult in the context of resuscitation with patients who are less mobilizable and less echogenic.

The subcostal assessment route is the classic emergency route. It allows for the analysis of the basic segmental kinetics of the left ventricle, an analysis of the Left Ventricular Ejection Fraction (LVEF), the search for pericardial effusion or even tamponade, or the search for right ventricular dilation. A measurement of CO via the right ventricular outflow tract using transthoracic echocardiography has never been described in the literature, although it is feasible, based on the same mathematical rationale as the standard measurement of cardiac output via the left ventricular outflow tract (which takes into account the diameter of the outflow tract and the subvalvular time-velocity integral [TVI]).

Since at all times the left (systemic) CO is equal to the right (venous return) CO, it is therefore possible to consider a measurement of CO via the subcostal route. By not complicating the standard care of patients in critical care, especially in situations of acute circulatory failure, and by adding only a few seconds or even minutes to an examination already recommended and routine in critical care, this evaluation approach seems interesting given the need and the recommendations in force on the monitoring of patients in intensive care and more particularly of DC.

Inclusion Criteria:

• Adult patient (Age ≥ 18 years)
• Patient admitted to the intensive care unit at Rouen University Hospital.
• Transthoracic echocardiography (TTE) is required upon admission or during the patient's stay for diagnostic assessment and/or therapeutic monitoring.

Exclusion Criteria:

• Person deprived of liberty by an administrative or judicial decision or person placed under judicial protection/guardianship or curatorship
• Patient not affiliated with the social security system
• Refusal by the patient or trusted person if the patient is incapable of expressing consent
• Pregnant woman
• Dying patient