Inclusion Criteria:  COMMON INCLUSION CRITERIA  Patient and/or trusted person (health care proxy) or close relative who has given their oral consent after being informed, Age ≥ 18 years old, Patients with grade 3 or 4 dependent oedema according to the classification of Brodovicz et al.  INCLUSION CRITERIA FOR THE SEPTIC SHOCK GROUP  Diagnosis within 24 hours of admission of septic shock as defined by : A probable or confirmed infection And a SOFA score ≥ 2 And the need to introduce vasopressors to obtain a MAP ≥ 65 mmHg despite adequate vascular filling And an arterial lactate > 2 mmol/l Average fluid balance since the diagnosis of sepsis > 1000 cc / 24 hours Sampling possible within 7 days after septic shock diagnosis  INCLUSION CRITERIA FOR THE CONTROL GROUP  Absence of sepsis and shock from any cause within 2 months prior to inclusion Collection is possible within 7 days of their admission to the participating department  Exclusion Criteria:  Disseminated intravascular coagulation (DIC) with haemorrhagic syndrome Acute condition that can mimic sepsis : Acute pancreatitis without signs of superinfection Metformin Intoxication Patient with an unfavourable prognosis within 24 hours Patient under legal protection (safeguard of justice, guardianship or tutelage) Pregnant or breastfeeding women Patient not affiliated to national health insurance