J Neurocrit Care.  2018 Jun;11(1):39-42. 10.18700/jnc.180041.

Sudden Bispectral Index Reduction and Suppression Ratio Increase Associated with Bradycardia in a Patient Undergoing Breast Conserving Surgery

• Jo Y
• Kim JM
• Jeon SB
• Park SU
• Kam HJ
• Shim WH
• Kim SH

• KMID: 2426212
• DOI: http://doi.org/10.18700/jnc.180041

Abstract

BACKGROUND
The bispectral index (BIS) is a valuable indicator for measuring sedation levels and patient consciousness. Recent reports have highlighted its clinical value as an indicator for anesthesia-related cerebral hypoperfusion and ischemic brain damage.
CASE REPORT
A 55-year-old female patient underwent right breast conservation surgery during general anesthesia. During surgery, the patient experienced abrupt bradycardia (heart rate of 36 bpm) without hypotension. During bradycardia, her BIS was severely reduced from 45 to 20 along with elvated suppression ratio (50). After injection of 0.5mg of atropine, her BIS level was recovered, her heart rate was increased, and her suppression ratio was decreased.
CONCLUSION
The patient recovered from anesthesia without showing any signs of neurological sequelae based on BIS level monitoring.

Keyword

Consciousness monitors; Bradycardia; Hypotension; Atropine

MeSH Terms

Anesthesia
Anesthesia, General
Atropine
Bradycardia*
Brain
Breast*
Consciousness
Consciousness Monitors
Female
Heart Rate
Humans
Hypotension
Mastectomy, Segmental*
Middle Aged
Atropine

Figure

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  Figure 1. A sudden decrease in bispectral index (BIS) and increase in suppression ratio (SR) accompanied by severe bradycardia (35 beats per minute). After atropine infusion (double-headed blue arrow), BIS and heart rate (HR) levels recovered to levels prior to surgery. MAP, mean arterial pressure.

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