Study of End Tidal Carbon Dioxide (EtCO2) Variation After an End- Expiratory Occlusion Test as a Predictive Criteria of Fluid Responsiveness in Mechanically Ventilated Patients

For each patient under mechanical ventilation, answering inclusions and non inclusions criteria, and eligible to a fluid perfusion, the physician in charge collect vital parameters such as cardiac frequency, blood pressure, cardiac output and end tidal carbon dioxide.

The cardiac output is measured by transthoracic echography, or invasive devices such as transpulmonary thermodilution or pulmonary arterial catheter.

The physician achieve a 15 seconds interruption of mechanical ventilation at end expiration, and collect the end tidal carbon dioxide variation.

Fluid perfusion of 500 ml of crystalloid is performed. Then the physician collect the same vital parameters, including a new cardiac output measure.

The patients for whom the cardiac output increased about more than 15 percent are considered as responders, the others are considered as non responders.

Furthermore, socio demographic parameter, reason for admission, parameters of mechanical ventilation, use of vasopressor drugs and water balance are collected.

Inclusion criteria

• older than 18 years old
• critically ill patients
• under mechanical ventilation
• whose cardiac output is measurable by transthoracic echography, or monitored by a transpulmonary thermodilution catheter or pulmonary arterial catheter
• eligible to a fluid perfusion, by the physician in charge appreciation

Exclusion criteria

• younger than 18 years old
• pregnant patients