To compare effects between entropy index and bispectral index on monitoring the depth of sedation induced by Dexmedetomidine combined with Midazolam for patients requiring long-term sedation in ICU.

65 patients sedated over 3 days in ICU from September 2013 to September 2015 were enrolled. The patients were randomly divided into two groups according to the sigle blind random number table methed. Group A (n=32): entropy group; Group B (n=33): BIS group. The target of RASS score is between -1 to 0 for both group, while the entropy index target in Group A is RE 65-80, SE 60-75, and BIS target in group B is from 60 to 80. During investigation, heart rate, respiratory rate, mean arterial pressure, and sedation satisfaction were monitored continuously. The time to achieve the desired sedation level and the dosage of sedatives in the first three days were recorded. Meanwhile, the incidence of adverse reactions was monitored respectively.

It taked less time to achieve the desired sedation level in Group A than that in Group B [(3.78±1.38) h vs (5.78±2.17) h, P=0.0047]. Group A had more effective sedation [(78.2±15.4)% vs (56.7±11.7)%, P=0.0034], less adverse reactions and lower dosage of sedatives than those in Group B.

Entropy index can be applied to monitor the depth of sedation in patients requiring long-term sedation, and reach sedation target in a shorter time, reduce the dosage of sedatives and adverse reactions as well.