Table.
Patient Characteristics and Process Measures in the CODA, ENGAGES, and Balanced Randomized Trials
| CODA | ENGAGES | Balanced | ||||
|---|---|---|---|---|---|---|
| BIS Group | Routine Care | EEG Guided | Usual Care | BIS 50 | BIS 35 | |
| N | 450 | 452 | 614 | 618 | 3316 | 3328 |
| Age (y) | 68 ± 8 | 68 ± 8 | 70 [65–75] | 69 [65–76] | 72 ± 7 | 72 ± 7 |
| ASA PS >II | 76 (17%) | 70 (16%) | 525 (86%) | 520 (84%) | 3316 (100%) | 3328 (100%) |
| Duration of surgery (min) | 126 ± 60 | 120 ± 66 | 265 [192–344] | 264 [186–349] | 200 [145–272] | 195 [144–274] |
| Age-unadjusted MAC | 0.48a | 0.78a | 0.69 [0.62–0.77] | 0.80 [0.71–0.86] | 0.62 [0.52–0.73] | 0.88 [0.74–1.04] |
| Age-adjusted MAC | 0.57 ± 0.29 | 0.93 ± 0.34 | 0.83 [0.75–0.93]b | 0.96 [0.85–1.03]b | 0.78 [0.65–0.91]b | 1.10 [0.93–1.30]b |
| BIS | 53.2 ± 8.9 | 38.6 ± 6.5 | Not reported | Not reported | 47.2 [43.7–50.5] | 38.8 [36.3–42.4] |
| Minutes with BIS <40 | 7.2 ± 7.8 | 22.8 ± 7.3 | 32 [9–81] | 60 [19–132] | Not reported | Not reported |
| Minutes of EEG suppression | Not reported | Not reported | 7 [1–23] | 13 [2–58] | Not reported | Not reported |
Values are mean ± standard deviation, number (%), or median [interquartile range].
Abbreviations: ASA PS, American Society of Anesthesiologists physical status; BIS, bispectral index; CODA, Cognitive Dysfunction after Anesthesia; EEG, electroencephalogram; ENGAGES, Electroencephalography Guidance of Anesthesia to Alleviate Geriatric Syndromes; MAC, minimum alveolar concentration.
The CODA trial reported age-adjusted MAC in the article. Unadjusted MAC (ie, where 1 is the MAC value for an average 40-year-old human) was calculated by applying the formula from Nickalls and Mapleson20 to the mean age-adjusted MAC and mean age reported in the article.
The ENGAGES trial and the Balanced Anesthesia Study reported unadjusted MAC in the articles. Age-adjusted MAC was calculated by applying the formula from Nickalls and Mapleson20 to the median unadjusted MAC and the mean (or median) age reported in the article.