Comparison of electrophysiologic monitors with clinical assessment of level of sedation.
OBJECTIVE
To assess the correlation between 2 clinical sedation scales and 2 electroencephalographic (EEG)-based monitors used during surgical procedures that required mild to moderate sedation.


METHODS
Patients scheduled for elective surgery participated in this Institutional review board-approved study from March 2003 to February 2004. Level of sedation was determined both clinically using the Ramsay and the Observer's Assessment of Alertness/Sedation scales and with 2 EEG measures (the Bispectral Index version XP [BIS XP] or the Patient State Analyzer [PSA 4000]). Correlation between these 2 measures of sedation were tested using nonparametric statistical tests.


RESULTS
The BIS XP monitor was used in 26 patients, and the PSA 4000 monitor was used in 24 patients. The Ramsay and Observer's Assessment of Alertness/Sedation scores correlated with each other (r = -0.96; P < .001) and with both the BIS XP (r = -0.89 and r = 0.91, respectively; P < .001) and the PSA 4000 (r = -0.80 and r = 0.80, respectively; P < .001) values. However, this correlation was strongest only at the extremes. Between the BIS XP and PSA 4000 values of 61 and 80, the clinical sedation scores varied greatly.


CONCLUSIONS
On the basis of our results, these EEG-based monitors cannot reliably distinguish between light and deep sedation.
Chisholm
Christopher J
CJ
Department of Anesthesiology, The New York Presbyterian Hospital, Columbia University College of Physicians and Surgeons, New York, NY 10032-3784, USA.
Zurica
Joseph
J
Mironov
Dmitry
D
Sciacca
Robert R
RR
Ornstein
Eugene
E
Heyer
Eric J
EJ
D016288:Computer Terminals; D016292:Procedural Sedation; D017558:Elective Surgical Procedures; D004569:Electroencephalography / Q000295:instrumentation*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D016343:Monitoring, Intraoperative / Q000295:instrumentation*; D015588:Observer Variation; D015203:Reproducibility of Results; D012189:Retrospective Studies