Neurological sedative indicators during general anesthesia with remimazolam

Area of Science:

• Anesthesiology
• Neuroscience
• Pharmacology

Background:

• The bispectral index (BIS) often appears high during general anesthesia with remimazolam.
• The reasons for elevated BIS and optimal sedation monitoring indicators for remimazolam are not fully understood.

Purpose of the Study:

• To evaluate sedation levels during remimazolam anesthesia using various monitoring indicators.
• To determine appropriate indicators for assessing sedation during remimazolam administration.

Main Methods:

• Thirty patients undergoing breast surgery under remimazolam anesthesia were studied.
• Simultaneous measurements of BIS®, Sedline®, and pupil resting diameters were performed.
• Remimazolam dosage was adjusted to maintain BIS between 40-60, with a maximum dose of 2 mg/kg/h.

Main Results:

• Mean intraoperative BIS was 50.6 ± 9.1 and Patient State Index (PSI) was 43.0 ± 11.8.
• Five patients had mean BIS > 60; eight had mean PSI > 50.
• Mean intraoperative spectral edge frequency (SEF) for BIS® was 15.3 ± 2.5 Hz and for Sedline® was 10.6 ± 3.0 Hz. Mean pupil diameter was 1.7 ± 0.2 mm. No awareness occurred.

Conclusions:

• Processed electroencephalograms (BIS, PSI) and BIS® SEF were relatively high during remimazolam anesthesia.
• SEF of Sedline® and pupillary diameter may serve as supportive indicators for confirming sedation levels.
• These findings aid in optimizing remimazolam anesthesia monitoring.