Dexmedetomidine for Non-invasive Ventilation After Chest Trauma (VENDETTA)

Crossover randomized controlled double blinded trial : The primary endpoint is the duration of Non Invasive Ventilation (NIV) session (minutes) with dexmedetomidine (DEX) or placebo. Secondary endpoints will be the sedation level as assessed by the Richmond Agitation Sedation Scale (RASS), the number of interventions to allow the completion of NIV session, the pain intensity level as assessed by visual analogue scale, the morphine and ketamine consumption during NIV sessions, the comparison of blood gas measurements before and after NIV sessions, the reproducibility of NIV cycles. The side effects of DEX will be notified.

Sodium Chloride 0,9 % Continuous IV infusion begun one hour before NIV session at 0.07 ml/kg/h Adaptation to sedation status by changing infusion speed of 0.02 ml/kg/h every 30 minutes up to 0.14 ml/kg/h Sedation objective Richmond Agitation Sedation Scale -3 (moderate sedation) to 0 (alert and calm)

Dexmedetomidine diluted to 10 µg/ml in Sodium Chloride 0,9 % Continuous IV infusion begun one hour before NIV session at 0.7 µg/kg/h (= 0.07 ml/kg/h) Adaptation to sedation status by changing infusion speed of 0.2 µg/kg/h (= 0.02 ml/kg/h) every 30 minutes up to 1.4 µg/kg/h (= 0.14 ml/kg/h) Sedation objective Richmond Agitation Sedation Scale -3 (moderate sedation) to 0 (alert and calm)

Inclusion Criteria: Blunt chest trauma with thoracic trauma score> 6, ICU admission and spontaneous breathing Exclusion Criteria: Contra indication for NIV or Dexmedetomidine as specified by the French marketing authorization