Entropy and bispectral index during anaesthesia in children

Abstract

Entropy™ is a new EEG based technology developed as a measure of depth of anaesthesia. The Entropy algorithm quantifies the degree of disorder in the EEG. During anaesthesia the disorder of the EEG, or entropy, falls. Entropy is independent of absolute frequency or amplitude of the EEG. This may make it suitable for paediatric anaesthesia. In this prospective observational blinded study we recorded the Entropy and Bispectral Index™ in 23 children undergoing general anaesthesia with isoflurane and nitrous oxide, supplemented with peripheral nerve blockade. We recorded Entropy at several times during anaesthesia, pre-awakening and 1-minute post-awakening. Entropy pre-awakening and 1 minute aft..