| BIS Reading | Clinical State | EEG |
|---|
| 0 | Unresponsive | Flat |
| 1–40 | Deep hypnotic state
<20, only possibility of intact protective reflexes and limited respiratory drive
<40, protective reflexes possibly intact; may respond to deep stimulation | <20, approaching burst suppression
<40, increased proportion of suppressed EEG |
| 41–60 | Moderate hypnotic state
Deep sedation; low probability of consciousness; unresponsive to verbal stimuli, low risk of recall | Normalized low-frequency activity (determined by proprietary method) |
| 61–90 | Light hypnotic state
Responds to loud verbal and deep tactile stimuli (less responsiveness with index near 60) | 60–70, beta-augmentation
70–80, synchronized high-frequency activity (beta-augmentation) |
| 91–100 | Awake | Normal EEG |