Background - goal of study: verify the concordance and correlation between the values of spectral BIS and State Entropy(SE) achieved in the anesthetic induction performed with propofol. Simultaneously determine the hypnotic depth expressed in BIS and SE values achieved after the administration of propofol. Verify if this hypnotic depth is maintained the time necessary to achieve optimal intubation conditions.
Materials and methods: the study population consisted of 47 patients undergoing general or urological surgery at the Hospital Clínico San Carlos-Madrid between January '12 and December 13. The main variable refers to the anesthetic depth during induction with propofol obtained by the non-dimensional analogue recording of the BIS and SE values from the beginning of the infusion of propofol until signs suggestive of excessive superficialisation were observed. Other variables that were registered where BP, HR and SpO2.
Results and Discussion: in 38% of cases, the registration was suspended due to an increase in SE over 60; 60% by simultaneous rise of BIS + SE above 50. One was suspended due to HD alterations. In the comparative study, the final numbers of SE were higher than those of BIS, with a mean of 56.1 vs 49.6. A discrepancy appeared in the analysis of the evolution of SE and BIS registers since the minimum values of SE (min = 6) were also lower than those of BIS (min = 11) and were more distant in time, reaching earlier. As a result, the ascending slope of the state entropy was steeper than de BIS one. It was also analyzed the relationship between BIS and SE minimum values in time and in numbers. The coincidence of the minimum values of BIS and SE, adding +/- 10 units as a reference, was 34,04%.
Conclusions: both BIS and SE provided a reliable guide to assess the adequacy of the hypnotic depth achieved. The degree of depth achieved with the initial bolus, according to the records, is maintained long enough for adequate endotracheal intubation conditions. However, SE can be a parameter that provides greater safety since it ascends earlier than BIS. It has shown to be more sensitive to variations in hypnotic depth and better predictor than BIS in the anesthetic stage emergence. It may be less reliable in assessing the exact degree of hypnotic depth when the level of consciousness is very low.

11 / Simultaneous register with BIS and State Entropy. Comparative in the induction with propofol.