In septic shock, the intensity and duration of low blood pressure can lead to a critical reduction in renal tissue perfusion and lead to the onset of more or less severe Acute Kidney Injury (AKI). Vasorin (Vasn) is a protein strongly expressed in large vessels and kidneys, whose functions are still poorly known. Previous experimental studies show that Vasn is associated with decreased Angiotensin II concentrations, a vessel contractility defect and early mortality. The investigators hypothesize that Vasn (the potential direct regulator of blood pressure) would be an early biomarker predicting the severity of AKI post septic shock, which may be associated with mortality from septic shock or lead to longer-term Chronic Renal Failure (CKD).