The independent Data Monitoring Committee (DMC) will have real-time access to the main variable "28-day mortality" (and allocation to study group "A" or "B") and will propose premature interruption of the trial based on sequential analysis if significant differences become apparent. The DMC will perform 5 interim analysis, one every 48 included patients and the criterium used will be a statistically significant difference at the level of p < 0,01 (S.J. Pocock. Clinical Trials. A practical Approach. John Wiley & Sons. New York. 1994).