Efficacy and safety of morphine titration on acute pain in emergency medical mobile units with initial bolus of 0.1 mg/kg plus 0.05 mg/kg versus morphine titration with initial bolus of 0.05 mg/kg plus 0.025 mg/kg

STUDY OBJECTIVE : Assess the efficacy of a morphine dose of 0.1 mg/kg versus a morphine dose of 0.05 mg/kg in pre-hospital pain METHODS : Consecutive patients with severe, acute pain defined as a verbal rating scale (VRS) of 60/100 or higher may be included. 106 patients at all are required in the study. They will be randomised in two groups : group A will receive an initial intravenous injection of 0.05 mg/kg then injections of 0.025 mg/kg every 5 minutes and group B will receive an initial intravenous injection 0.1 mg/kg then injections of 0.05 mg/kg every 5 minutes. The pain scale will be checked every 5 minutes during 30 minutes. The titration will be stopped before, if the VRS is < or = 30. The patient will be followed during the study until 60 minutes.

Inclusion Criteria:

• Severe, acute pain defined by a VRS of 60/100 or higher
• Male or female over 18 years
• Cared by a medical emergency care unit
• Written informed consent
• Affiliated to social security

Exclusion Criteria:

• A known opioid or paracetamol hypersensitivity
• Patient not agree ta participate at the study
• Pregnancy
• Uncontrolled epilepsia
• Incapacity to understand the VRS
• Renal, respiratory, or liver disease
• Patients who have received sedative drugs or alcohol (< 6h)
• Acute respiratory, haemodynamic or neurologic failure
• Patients who have already received an analgesic (< 6h)
• Drug addiction
• Patients under protection of justice