Relation between bispectral index and plasma catecholamines after oral diazepam premedication

Area of Science:

• Anesthesiology
• Neurophysiology
• Pharmacology

Background:

• Traditional methods for assessing anesthetic premedication efficacy, like sedative scores and visual analogue scales, are prone to subjectivity and placebo effects.
• Plasma catecholamine concentrations offer an objective measure of patient anxiety.
• Bispectral electro-encephalographic analysis and the bispectral index (BIS) monitor have emerged as tools for measuring sedation depth.

Purpose of the Study:

• To investigate the relationship between bispectral index values and plasma catecholamine concentrations following oral diazepam premedication.
• To determine if the bispectral index monitor can objectively assess the sedative effects of diazepam.

Main Methods:

• Twenty-eight patients undergoing elective surgery were randomized into two groups: diazepam premedication (n=14) and no premedication (n=14).
• The diazepam group received 10 mg oral diazepam and 75 mg roxatidine, while the control group received 75 mg roxatidine only, 90 minutes prior to surgery.
• Bispectral index monitoring was applied upon arrival in the operating theatre, and plasma catecholamine levels were measured via high-performance liquid chromatography in the diazepam group.

Main Results:

• The bispectral index was significantly lower in the diazepam premedication group (93.5 ± 773.5) compared to the no premedication group (96.1 ± 1.8) (P < 0.05).
• A significant positive correlation was observed between bispectral index values and plasma norepinephrine levels (r = 0.567, P < 0.05).

Conclusions:

• The bispectral index monitor appears to be a reliable tool for detecting the effects of oral diazepam premedication.
• The findings suggest that bispectral index monitoring can objectively quantify the anxiolytic and sedative effects of premedication, complementing traditional assessment methods.