Regarding spectral entropy monitoring of anaesthetic depth compared with bispectral index monitoring, the distinguishing feature of response entropy is that it:
- A Includes higher frequencies up to 47 Hz incorporating facial EMG, so it responds more rapidly than state entropy ✓
- B Uses only frontal electromyographic activity and ignores the EEG
- C Is calculated exclusively from the raw EEG below 32 Hz and changes more slowly than state entropy
- D Requires neuromuscular blockade-free conditions to generate any numerical value
Correct answer: A. Includes higher frequencies up to 47 Hz incorporating facial EMG, so it responds more rapidly than state entropy
Explanation
Response entropy is computed from EEG plus facial EMG frequencies up to 47 Hz, while state entropy uses only EEG up to 32 Hz. Because facial EMG activity increases before cortical arousal becomes evident in the EEG, response entropy rises earlier and faster than state entropy, giving an early warning of awakening. State entropy is the more stable measure of hypnotic depth, and neither index requires absence of neuromuscular blockade.
Reference: Miller's Anesthesia, 9th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.