Depth of anesthesia can be best assessed by

Ans. d (Bispectral Index) (Ref. CSDT 12th/pg. Chapter 11 & Anaesthesia by Ajay Yadav, 2nd/pg. 45)MONITORING THE DEPTH OF ANESTHESIA# The Bispectral Index is a monitor that can be used in many cases to assess anesthetic depth.# It is measured from superficial scalp electrodes and is a processed electroencephalogram.# It is possible that this type of monitoring approach will be increasingly used to assess anesthetic depth.# A Bispectral index (BIS) monitor is a modern neurophysiological monitoring device which continually analyses a patient's electroencephalogram during general anesthesia to assess the level of consciousness during anesthesia.# The "depth of anesthesia" is commonly used as a surrogate for "the likelihood of forming experiences or memory."# BIS is therefore best described as a monitor of the depth of the hypnotic component of anesthesia or sedation.# BIS demonstrates a dose-response relationship with inhalational and hypnotic intravenous agents, such as propofol and midazolam, which is independent of the agent(s) being used and correlates with clinical assessments of the level of consciousness.# Ketamine, however, causes EEG activation, complicating BIS interpretation.