Table 4: Predicted and Observed Outcomes of Bispectral Index Monitoring From the Reviewed Studies.

Stage of Surgery	Study (year)	Predicted Outcome According to the Bispectral Index (BIS) Score	Observed Outcome
Before surgery	Kerssens et al. (2003) (26)	With a BIS score of 60 to 70, there should be a response to a command most of the time. Patients with recall should demonstrate higher BIS values.	No response was observed for 887 (82%) commands. The mean BIS value was 63.2 (SD, 4.9) Patients with and without recall had the same mean BIS values (67).
During intubation	Schneider et al. (2002) (33)	With a BIS score below 55, no patient should show an awareness reaction. Patients who have awareness reactions should have higher BIS scores compared with those who do not have awareness reactions.	8 of 20 patients (40%) showed an awareness reaction after intubation. Those who responded and those who did not were clearly in different states of hypnosis, but the median BIS score was 52 for responders and 54 for nonresponders. This study shows that a BIS score between 50 and 60 before intubation does not guarantee that a patient will not experience awareness after intubation. Patients with and without awareness reactions had similar mean BIS values (71 and 69).
During surgery	Schneider et al. (2003) (29)	In unconscious patients, BIS scores should be less than 60.	The mean BIS score was 66 (SD, 17). The wide variation in BIS scores led to a wrong classification in some cases.
	Yeo and Lo (2002) (35)	With a median BIS score of 70 at the time of skin incision, anesthesia should be light, and most of the patients should experience recall.	No patient experienced recall or awareness.
	McCann et al. (2002) (34)	During surgery and at the time of the intraoperative wake-up test, BIS scores should be less than 60.	The mean BIS score was 72 (SD, 8).

^*SD indicates standard deviation.