Effect of Hydrocortison on Post-ischemic Flow-mediated Dilation and on Thenar Oxygen Saturation in Human Septic Shock.

Overview

The main objectives of the study are 1)to examine the immediate (2 hours) and delayed (8 hours) effects of intravenous hydrocortison on macro and microvascular post-ischemic vasoreactivity, in septic shock adult patients; 2) to examine possible correlations between post-ischemic flow-mediated dilation (FMD) of the brachial artery (assessed by ultrasound imaging) and post-ischemic recovery slope of the thenar oxygen saturation (StO2) (assessed by near-infrared spectroscopy).

Two primary end points, considered as reflecting vasoreactivity will be assessed : 1. Flow-mediated dilation (FMD) of the brachial artery, measured by ultrasound imaging, expressed in mm or in percentage, will be calculated from artery diameters measured before and after a vascular occlusion test (cuff around arm or forearm). 2. recovery slope of thenar oxygen saturation (StO2), assessed by near infrared spectroscopy (NIRS), expressed in %/second, will be recorded after the vascular occlusion test. The two primary end points (FMD and recovery slope of StO2)will be assessed at the following timepoints : * baseline (before first injection of placebo or hydrocortison) * 2 hours after first injection of placebo or hydrocortison * 2 hours after second injection of placebo or hydrocortison (i.e. 8 hours after first injection) * 4 to 6 hours after third injection * 4 to 6 hours after fourth injection (optional)

Conditions