The aim of this study is to demonstrate a significant reduction of at least 25% in opioid consumption at 48 hours of management of severe trauma, while demonstrating non-inferiority in terms of analgesia, in a group of patients receiving a continuous infusion of low dose ketamine compared to a placebo group.

Inclusion Criteria:

• Male or female adult
• Trauma patient presenting at least 2 lesions in two different regions as defined by the ISS (injury severity score) (Head or neck, Face, Thorax, Abdomen and pelvic contents, Upper limbs or pelvic girdle, Lower limbs, External (any skin surface).
• Patient presenting at least two regional disorders classified as moderate to maximum defined by an AIS (Abbreviated Injury Scale)> 1.
• Patient having signed an informed consent

Exclusion Criteria:

• Patients with an indication for deep sedation (intracranial hypertension or acute respiratory distress syndrome).
• Patient in whom the infusion could not be started within the first 6 hours of initial treatment.
• Patient whose state of consciousness is incompatible with understanding the protocol.
• Patient with chronic unbalanced arterial hypertension.
• Patient with severe heart failure.
• Patient with a BMI> 35 kg / m² or a weight of more than 120 kg.
• Patient with chronic analgesic consumption defined by consumption of opioid derivatives for more than a week for an intercurrent illness.
• Presence of a history of chronic pain.
• Presence of a history of epilepsy.
• Presence of a history of psychosis or drug addiction.
• Presence of a history of stroke.
• Patients with an allergy to the molecule or excipients composing ketamine
• Patients with an allergy to the molecule or to the excipients making up sufentanil or paracetamol.
• Pregnant or breastfeeding woman.
• Patient not understanding French.
• Protected adult patient (under guardianship, curatorship or legal protection).