Regional analgesia, based on its physiological effects and efficacy, is used for optimal perioperative pain relief. However, for acute pain in multiple trauma patients in a critical condition, it has not been prospectively studied. The use of regional anaesthesia in this group of patients extend to the management of trauma patients and of other painful procedures performed at the patient's bed. The use of RA in such patients must be analyzed in the light of associated conditions that can increase the risk of systemic toxicity and complications: coagulopathies, infection, immunosuppressive states, sedation and problems associated with mechanical ventilation. The investigators aim to assess the role of continuous peripheral nerve blocks (CPNB) in multiple trauma patients, in order to show the benefits in terms of opiates consumption decrease, sedation limitation, improvement in ventilator free days and patients outcome

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.

Inclusion Criteria:

• Patient older than 18 years
• Multiple trauma Patient ( with or without head trauma)
• Patient admitted to ICU
• Patient with limb fracture (s)
• Patient requiring sedation and mechanical ventilation for more than 48h
• Patient affiliated to a social security system
• Patient whose informed consent was obtained from the family

Exclusion Criteria:

• Patient currently enrolled in another trial
• Patient with coagulation disorders
• Patient whose access to the puncture sites is not feasible (underlying lesions)
• Patient with allergies to local anesthetics (LA)
• Patient whose family did not give informed consent
• Patient younger than 15 years and 3 months
• Tetraplegic Patient
• Dying patients
• Patients with more than 3 different fracture sites

The investigator responsible for assessing sedation and adjusting dosages hypnotic and morphinic (according to objectives) will not be aware of the result of the randomization.