Impact of Continuous Regional Analgesia in Severe Trauma Patients

Inclusion of multiple trauma patients with limb fractures and need for sedation and prolonged mechanical ventilation. Patients should meet the following criterias: pressure of cerebral perfusion\>60mmHg, normothermia, PaCO2 35-40 mmHg, pH\> 7.20, Normal coagulation parameters, Hb\> 8g / dl (without head trauma) or Hb\> 10g / dl (if associated head trauma). Randomization in two patients groups: "RA group" versus "NoRA Group Methods: group without locoregional anesthesia: Sedation using midazolam and sufentanil: Multi-Daily adjustment of doses every 4 hours using Behavioral Pain Scale score \<4 and Ramsay Score \> 4. group with locoregional anesthesia: Sedation using midazolam and sufentanil: Multi-Daily adjustment of doses every 4 hours using Behavioral Pain Scale score \<4 and Ramsay Score \> 4 + peronerval block catheter from 0 to 24h after admission in intensive care unit using ropivacaine 0.2% with a continuous infusion at 1mL/10 Kg /H Follow-up up to 5 days for the 2 group. The main objective: sufentanil consumption (reported in µg / kg / d) for the same levels of Behavioral Pain Scale and Ramsay Scales values.