BIS and Ramsay score in critically ill patient: what future?

Area of Science:

• Critical Care Medicine
• Neurophysiology
• Pharmacology

Background:

• The Bispectral Index (BIS) is a validated tool for assessing sedation levels, particularly for hypnotic drug effects.
• Its application in Intensive Care Units (ICUs) remains limited despite its potential.
• This study explores BIS utilization for monitoring sedation in critically ill patients.

Purpose of the Study:

• To evaluate the correlation between the Bispectral Index (BIS) and the Ramsay Sedation Scale (RSS).
• To assess BIS score fluctuations in response to varying sedative dosages (propofol and midazolam).
• To determine the potential of BIS as a monitoring tool in the ICU setting.

Main Methods:

• Twenty mechanically ventilated patients with severe lung disease were enrolled.
• Patients received continuous infusions of propofol and/or midazolam to maintain an RSS of 4.
• BIS and RSS were recorded simultaneously every 30 minutes for 960 total observations.

Main Results:

• A progressive decrease in BIS scores was observed with increasing Ramsay scores (e.g., RSS=2, BIS=88±15.1; RSS=6, BIS=52.2±10.7).
• Significant correlations were found between BIS and propofol dosage.
• A correlation was also noted between the Ramsay score and systolic blood pressure.

Conclusions:

• The study demonstrates a robust correlation between the Bispectral Index (BIS) and the Ramsay Sedation Scale.
• BIS monitoring is a viable method for assessing sedation depth in ICU patients.
• Findings support the use of BIS for optimizing sedative administration in critical care.