Does the Time Between the End of Vascular Filling and Evaluation of Its Effectiveness Modify Fluid Challenge Results in Septic Shock?

The secondary objectives of this study are :

A. To assess changes in different ultrasound parameters: E wave , E / A ratio , E / E ' in the event of vascular filling and construct a dose response curve for vascular filling.

B. To determing a threshold value for the mitral E wave velcoity that can predict a positive response to volume expansion at T10 defined by a 15% increase in the sub aortic velocity time integral (ITV) after 500 ml of crystalloids in 10 minutes.

C. To determine a threshold value for theITV at T0 that can predict a positive response to volume expansion at T10 defined by a 15% increase in the ITV after 500 ml of crystalloids in 10 minutes.

D. To evaluate the proportion of responders at T10 becoming non-responders at T20.

E. To evaluate the proportion of nonresponders at T10 and responders at T30 .

F. To estimate the proportion of patients changing status regardless of the direction of change between T10 and T30 .

Inclusion criteria

• The patient has given his/hers consent or the patient is in an emergency situation (commitment to obtain the consent of the patient as soon as his/her condition permits)
• Patient affiliated or beneficiary of a health insurance plan
• Patient with septic shock: proven or suspected infection associated with hypotension or lactate> 4 mmol / l or organ dysfunction. Hypotension despite fluid resuscitation of 20 to -40 ml / kg.
• Patient under controlled mechanical ventilation
• Patient requiring vascular filling according to the following criteria:
• oliguria <0.5 ml / kg / h for at least 2h
• skin mottling
• Arterial Lactate > 2 mmol / l
• SvcO2 <70% or SvO2 <65%
• Patient on noradrenaline.

Exclusion criteria

• The patient is has in another interventional study that might change the results of this study within the past 3 months
• The patient is under judicial protection, under tutorship or curatorship
• The patient refuses to sign the consent
• The patient is pregnant, parturient, or breastfeeding
• Valvular pathology: grade III and IV aortic or mitral insufficiency
• Non sinus electrocardiogram
• Non-echogenic patient
• Patient with any spontaneous breathing
• Moribund patient