Effect of atracurium and rocuronium on the state and response entropy during isoflurane anesthesia: randomized prospective study

Abstract

Abstract Background Several researches have examined the impact of inhalation anesthetics, intravenous anesthetics, and muscle relaxants on spectral entropy, but many did not evaluate the extent of neuromuscular block. Besides, they did not inspect the impact of distinct degrees of neuromuscular blockade on spectral entropy under dissimilar saturations of isoflurane inhalation. Hence, this study has evaluated variant degrees of minimum alveolar concentration (MAC) to estimate the isoflurane concentration, along with various levels of neuromuscular blockade. This study aims to evaluate the effect of muscle relaxants (atracurium and rocuronium) on entropy readings (state, response entropy, and response-state difference) during isoflurane anesthesia. This is a prospective randomized study, as forty patients have been included and divided into two study groups: patients in group A received atracurium, while patients in group R received rocuronium. Under 50% and 100% neuromuscular blockage, state and response entropy were observed at MACs of 0.8% and 1%, respectively. Results There was a positive correlation between state (SE) and response entropy (RE) at baseline, different MACs, and different trains of four (TOF) for both atracurium and rocuronium. State and response entropy decreased with increasing MAC of isoflurane (P < 0.001), while atracurium and rocuronium at TOF 50% and 100% showed no effect on SE, RE, or RE-SE (P > 0.05). Conclusions State and response entropy can be used effectively to evaluate the depth of anesthesia at different isoflurane MAC and atracurium or rocuronium doses. Registration number ClinicalTrials.gov identifier: NCT 05097508, Registered October 5, 2021 (prospectively registered), http://www.ClinicalTrial.gov