Korean J Anesthesiol.  2018 Oct;71(5):368-373. 10.4097/kja.d.18.27154.

Influence of electrocautery-induced electromagnetic interference on quantitative electroencephalographic monitoring of hypnosis during general anesthesia: comparison between the ADMS® and the BIS VISTATM

• Kim DH
• Yoo JY
• Kim JY
• Ahn SH
• Kim S
• Min SK

• KMID: 2424680
• DOI: http://doi.org/10.4097/kja.d.18.27154

Abstract

BACKGROUND
Hypnosis monitors analyze small-amplitude electrical signals transmitted from the brain that could be exposed to the electromagnetic field that occurs around the body during electrocautery (ECT). We investigated the influence of ECT on hypnosis monitoring during anesthesia.
METHODS
We simultaneously monitored BIS and uCON during 50 gynecologic oncology surgeries. During the episodes of ECT, we compared the absolute difference (a-Diff) between the baseline index and the most deviated index after ECT over either 30-60 s (ECT30-60) or more than 60 s (ECT > 60) between the monitors. We also investigated the bias and the limits of agreement between the monitors.
RESULTS
Between the two monitors, the a-Diff of ECT30-60 was 1.4 ± 1.1 for the BIS, which was significantly greater than 0.6 ± 0.9 for the uCON (P = 0.003), and the a-Diff of ECT > 60 was 16.5 ± 8.2 for the BIS, which was also significantly greater than 1.4 ± 1.3 for uCON (P < 0.001). The intra-monitor index differences showed that the BIS during ECT > 60 was significantly greater than that during ECT30-60 (P < 0.001), but the uCON showed no significant difference between ECT30-60 and ECT > 60 (P = 0.056). The estimated bias between the monitors was 6.3 ± 9.8 and 95% limits agreement was -12.3 to 25.0.
CONCLUSIONS
Prolonged ECT intervention might lead to spurious estimations of quantitative EEG indexes. Therefore, hypnosis should be clinically assessed in combination with scrutinized judgment of relevant clinical symptoms and signs for hypnosis.

Keyword

Anesthesia; Electrocoagulation; Electroencephalography; Hypnosis

MeSH Terms

Anesthesia
Anesthesia, General*
Bias (Epidemiology)
Brain
Electrocoagulation
Electroencephalography
Electromagnetic Fields
Hypnosis*
Judgment
Magnets*