Comparison of SNAP ™ II and BIS Vista indices during normothermic cardiopulmonary bypass under isoflurane anesthesia

Kinjal M. Patel; Saadia S. Sherwani; Paul C. Fitzgerald; Robert J. McCarthy

doi:10.1007/s10877-011-9313-1

Comparison of SNAP ^™ II and BIS Vista indices during normothermic cardiopulmonary bypass under isoflurane anesthesia

Kinjal M. Patel, Saadia S. Sherwani, Paul C. Fitzgerald, Robert J. McCarthy^*

^*Corresponding author for this work

Research output: Contribution to journal › Article › peer-review

Abstract

Objective: Processed EEG monitoring during cardiopulmonary bypass (CPB) may help determine loss of consciousness and depth of anesthesia. This study compared the SNAP ^™ II and BIS Vista monitors in patients undergoing isoflurane anesthesia with normothermic CPB. Methods: 40 subjects undergoing CPB with isoflurane anesthesia were enrolled. Subjects were premedicated with 1-2 mg midazolam approximately 5 min prior to acquisition of baseline index values and anesthesia induced with midazolam and fentanyl. Anesthesia was maintained with isoflurane, midazolam, and fentanyl and a cis-atracurium infusion. SNAP ^™ II (version 1.2.9 algorithm 1.88) and BIS Vista (application version 3.00 platform version 2.03) indices were recorded at baseline, pre-induction, post-intubation, incision, start of CPB, every 15 min during CPB, end of CPB, and end of case. Agreement between methods was determined using Pearson correlation and the Bland-Altman method with repeated observa- tions. Results: Twenty-four male and 12 female subjects completed the analysis. The correlation between SNAP ^™ II and BIS Vista index values was 0.61 (P < 0.005). A linear relationship between the difference in the indices and the average index values was observed following the induction of anesthesia. In awake subjects, the bias between the SNAP ^™ II and BIS Vista was 5 (95% CI 3-7). The limits of agreement were 23 (95% CI 19-26) and -13 (95% CI -9 - 16). During anesthesia, the mean difference on a log scale was 0.11 (95% CI 0.09-0.12). The limits of agreement were 0.43 (95% CI 0.40-0.45) and -0.21 (95% CI -0.18 - 0.24). The antilog of the mean difference demonstrated that the SNAP ^™ II value was 28% (95% CI 24-33%) higher than the BIS Vista value following induction of anesthesia. Conclusions: The SNAP ^™ II monitor demonstrates a consistently positive bias during cardiopulmonary bypass under isoflurane anesthesia compared with the BIS Vista.

Original language	English (US)
Pages (from-to)	365-370
Number of pages	6
Journal	Journal of Clinical Monitoring and Computing
Volume	25
Issue number	6
DOIs	https://doi.org/10.1007/s10877-011-9313-1
State	Published - Dec 2011

Keywords

SNAP index
bispectral index
cardiac sugery
depth of anesthesia
isoflurane
loss of consciousness
processed EEG

ASJC Scopus subject areas

Critical Care and Intensive Care Medicine
Anesthesiology and Pain Medicine
Health Informatics

Access to Document

10.1007/s10877-011-9313-1

Cite this

@article{228562497e324db7977775e9eddedb01,

title = "Comparison of SNAP {\texttrademark} II and BIS Vista indices during normothermic cardiopulmonary bypass under isoflurane anesthesia",

abstract = "Objective: Processed EEG monitoring during cardiopulmonary bypass (CPB) may help determine loss of consciousness and depth of anesthesia. This study compared the SNAP {\texttrademark} II and BIS Vista monitors in patients undergoing isoflurane anesthesia with normothermic CPB. Methods: 40 subjects undergoing CPB with isoflurane anesthesia were enrolled. Subjects were premedicated with 1-2 mg midazolam approximately 5 min prior to acquisition of baseline index values and anesthesia induced with midazolam and fentanyl. Anesthesia was maintained with isoflurane, midazolam, and fentanyl and a cis-atracurium infusion. SNAP {\texttrademark} II (version 1.2.9 algorithm 1.88) and BIS Vista (application version 3.00 platform version 2.03) indices were recorded at baseline, pre-induction, post-intubation, incision, start of CPB, every 15 min during CPB, end of CPB, and end of case. Agreement between methods was determined using Pearson correlation and the Bland-Altman method with repeated observa- tions. Results: Twenty-four male and 12 female subjects completed the analysis. The correlation between SNAP {\texttrademark} II and BIS Vista index values was 0.61 (P < 0.005). A linear relationship between the difference in the indices and the average index values was observed following the induction of anesthesia. In awake subjects, the bias between the SNAP {\texttrademark} II and BIS Vista was 5 (95% CI 3-7). The limits of agreement were 23 (95% CI 19-26) and -13 (95% CI -9 - 16). During anesthesia, the mean difference on a log scale was 0.11 (95% CI 0.09-0.12). The limits of agreement were 0.43 (95% CI 0.40-0.45) and -0.21 (95% CI -0.18 - 0.24). The antilog of the mean difference demonstrated that the SNAP {\texttrademark} II value was 28% (95% CI 24-33%) higher than the BIS Vista value following induction of anesthesia. Conclusions: The SNAP {\texttrademark} II monitor demonstrates a consistently positive bias during cardiopulmonary bypass under isoflurane anesthesia compared with the BIS Vista.",

keywords = "SNAP index, bispectral index, cardiac sugery, depth of anesthesia, isoflurane, loss of consciousness, processed EEG",

author = "Patel, {Kinjal M.} and Sherwani, {Saadia S.} and Fitzgerald, {Paul C.} and McCarthy, {Robert J.}",

year = "2011",

month = dec,

doi = "10.1007/s10877-011-9313-1",

language = "English (US)",

volume = "25",

pages = "365--370",

journal = "Journal of Clinical Monitoring and Computing",

issn = "1387-1307",

publisher = "Kluwer Academic Publishers",

number = "6",

}

TY - JOUR

T1 - Comparison of SNAP ™ II and BIS Vista indices during normothermic cardiopulmonary bypass under isoflurane anesthesia

AU - Patel, Kinjal M.

AU - Sherwani, Saadia S.

AU - Fitzgerald, Paul C.

AU - McCarthy, Robert J.

PY - 2011/12

Y1 - 2011/12

N2 - Objective: Processed EEG monitoring during cardiopulmonary bypass (CPB) may help determine loss of consciousness and depth of anesthesia. This study compared the SNAP ™ II and BIS Vista monitors in patients undergoing isoflurane anesthesia with normothermic CPB. Methods: 40 subjects undergoing CPB with isoflurane anesthesia were enrolled. Subjects were premedicated with 1-2 mg midazolam approximately 5 min prior to acquisition of baseline index values and anesthesia induced with midazolam and fentanyl. Anesthesia was maintained with isoflurane, midazolam, and fentanyl and a cis-atracurium infusion. SNAP ™ II (version 1.2.9 algorithm 1.88) and BIS Vista (application version 3.00 platform version 2.03) indices were recorded at baseline, pre-induction, post-intubation, incision, start of CPB, every 15 min during CPB, end of CPB, and end of case. Agreement between methods was determined using Pearson correlation and the Bland-Altman method with repeated observa- tions. Results: Twenty-four male and 12 female subjects completed the analysis. The correlation between SNAP ™ II and BIS Vista index values was 0.61 (P < 0.005). A linear relationship between the difference in the indices and the average index values was observed following the induction of anesthesia. In awake subjects, the bias between the SNAP ™ II and BIS Vista was 5 (95% CI 3-7). The limits of agreement were 23 (95% CI 19-26) and -13 (95% CI -9 - 16). During anesthesia, the mean difference on a log scale was 0.11 (95% CI 0.09-0.12). The limits of agreement were 0.43 (95% CI 0.40-0.45) and -0.21 (95% CI -0.18 - 0.24). The antilog of the mean difference demonstrated that the SNAP ™ II value was 28% (95% CI 24-33%) higher than the BIS Vista value following induction of anesthesia. Conclusions: The SNAP ™ II monitor demonstrates a consistently positive bias during cardiopulmonary bypass under isoflurane anesthesia compared with the BIS Vista.

AB - Objective: Processed EEG monitoring during cardiopulmonary bypass (CPB) may help determine loss of consciousness and depth of anesthesia. This study compared the SNAP ™ II and BIS Vista monitors in patients undergoing isoflurane anesthesia with normothermic CPB. Methods: 40 subjects undergoing CPB with isoflurane anesthesia were enrolled. Subjects were premedicated with 1-2 mg midazolam approximately 5 min prior to acquisition of baseline index values and anesthesia induced with midazolam and fentanyl. Anesthesia was maintained with isoflurane, midazolam, and fentanyl and a cis-atracurium infusion. SNAP ™ II (version 1.2.9 algorithm 1.88) and BIS Vista (application version 3.00 platform version 2.03) indices were recorded at baseline, pre-induction, post-intubation, incision, start of CPB, every 15 min during CPB, end of CPB, and end of case. Agreement between methods was determined using Pearson correlation and the Bland-Altman method with repeated observa- tions. Results: Twenty-four male and 12 female subjects completed the analysis. The correlation between SNAP ™ II and BIS Vista index values was 0.61 (P < 0.005). A linear relationship between the difference in the indices and the average index values was observed following the induction of anesthesia. In awake subjects, the bias between the SNAP ™ II and BIS Vista was 5 (95% CI 3-7). The limits of agreement were 23 (95% CI 19-26) and -13 (95% CI -9 - 16). During anesthesia, the mean difference on a log scale was 0.11 (95% CI 0.09-0.12). The limits of agreement were 0.43 (95% CI 0.40-0.45) and -0.21 (95% CI -0.18 - 0.24). The antilog of the mean difference demonstrated that the SNAP ™ II value was 28% (95% CI 24-33%) higher than the BIS Vista value following induction of anesthesia. Conclusions: The SNAP ™ II monitor demonstrates a consistently positive bias during cardiopulmonary bypass under isoflurane anesthesia compared with the BIS Vista.

KW - SNAP index

KW - bispectral index

KW - cardiac sugery

KW - depth of anesthesia

KW - isoflurane

KW - loss of consciousness

KW - processed EEG

UR - http://www.scopus.com/inward/record.url?scp=84655167836&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84655167836&partnerID=8YFLogxK

U2 - 10.1007/s10877-011-9313-1

DO - 10.1007/s10877-011-9313-1

M3 - Article

C2 - 22076615

AN - SCOPUS:84655167836

SN - 1387-1307

VL - 25

SP - 365

EP - 370

JO - Journal of Clinical Monitoring and Computing

JF - Journal of Clinical Monitoring and Computing

IS - 6

ER -