The critically ill patient is one of the most complex cases with regard to the optimization of the anesthesia, as well as postoperative management. One of the most important steps in the complex management of such patients is the modulation of anesthesia for every patient needs. We start with the assumptions that the optimization of anesthesia should depend on each patient, being conducted in an individual manner. We also believe that by individualizing the anesthesia by monitoring the entropy it is possible to obtain an appropriate management regarding hemodynamic complications during anesthesia including tachycardia, bradycardia, hypotension and hypertension.

Inclusion Criteria:

• ASA physical status I, II, III;
• written consent accepted to be enrolled in the study; in polytrauma patients in the operation theatre who are brought directly through the emergency department, written consent is obtained from the relatives, in accordance to the national law number 206, of 2004, for a good and correct scientific research, in the situation where the patient is no capable to sign or give the written consent;

Exclusion Criteria:

• cardiac pacemaker;
• atrial fibrillation at the time of presentation in the operation theatre;
• any subject with epidural catheter, placed pre-operatively;
• allergy to Propofol or another anesthetic drugs;
• pregnancy;
• presence of neuromuscular disease;
• presence of neurologic disease;

All patients who needs general anesthesia and meet the inclusion criteria.