Effects of Increasing Mean Arterial Pressure on Renal Function in Patients With Shock and With Elevated Central Venous Pressure

Current recommandation for mean arterial pressure (MAP) target is 65 mmHg for septic shock, but optimal target to prevent acute renal failure (ARF) remains unknown. High central venous pressure (CVP) can lead to acute renal failure through venous congestion , and is associated with acute renal failure in intensive care unit. A decrease of renal perfusion pressure, defined by MAP - CVP, has been shown to be associated with risk of acute renal failure. The main objective of this trial is to evaluate if an optimisation of renal perfusion pressure, by a higher MAP when CVP is high (≥ 12 cmH2O), can improve renal function. In this interventional monocenter trial, each patient will be evaluated during 2 consecutive periods of 6 hours, with a temporary MAP target * Target at 65-70mmHg during 6 hours * Target at 80-85mmHg during 6 hours Patients will be randomized into two groups to define the order of targets. There will be a stratification on previous arterial hypertension. Renal function will be measured at the end of each period.