Setting targets for sedation with a target-controlled propofol infusion

Area of Science:

• Anesthesiology
• Pharmacology

Background:

• Sedation is crucial for patient comfort during procedures like muscle biopsy.
• Target-controlled infusion (TCI) of propofol offers precise drug delivery.
• Establishing effective propofol doses for specific sedation levels is essential for procedural success.

Purpose of the Study:

• To determine the 50% effective dose (ED50) of propofol for different sedation levels.
• To evaluate propofol's efficacy in unpremedicated patients undergoing muscle biopsy under femoral nerve block.

Main Methods:

• Thirty unpremedicated patients undergoing muscle biopsy received propofol via a Diprifusor TCI system.
• Propofol infusion started at 0.8 µg/mL and was titrated by 0.1 µg/mL increments.
• Sedation levels were assessed, and target propofol concentrations corresponding to ED50 were identified.

Main Results:

• The ED50 target propofol concentrations for sedation levels 2 (drowsy), 3 (drowsy, responds to verbal stimulation), and 4 (responsive to physical stimulation only) were 1.0, 1.6, and 2.1 µg/mL, respectively.
• Spontaneous movement occurred in some patients at sedation level 3, potentially hindering surgery.
• Oxygen supplementation was advised for sedation level 4.

Conclusions:

• Target-controlled propofol infusion effectively achieves varying sedation depths for muscle biopsy.
• Specific ED50 concentrations are identified for achieving desired sedation levels during this procedure.
• Careful titration and monitoring, including oxygen supplementation at deeper sedation levels, are recommended.