Manual versus target-controlled infusions of propofol

Area of Science:

• Anesthesiology
• Pharmacology

Background:

• Target-controlled infusion (TCI) systems for propofol anesthesia may lead to increased drug administration.
• This can potentially cause delayed patient emergence and recovery from anesthesia.

Purpose of the Study:

• To investigate if higher propofol doses with TCI systems are linked to deeper hypnosis.
• To compare hypnosis depth using bispectral index (BIS) monitoring between manual and TCI propofol administration.

Main Methods:

• Fifty non-premedicated patients undergoing elective surgery were randomized to manual or TCI propofol infusion.
• Anesthesia was maintained using standard clinical criteria, with BIS scores monitored by an independent observer.
• Propofol administration rates and BIS values were recorded for both groups.

Main Results:

• The TCI group received significantly higher total propofol doses (9.9 mg.kg(-1).h(-1)) compared to the manual group (8.1 mg.kg(-1).h(-1)).
• BIS scores were significantly lower in the TCI group during the initial 15 minutes of anesthesia.
• Despite dose differences, emergence and recovery times were comparable between groups.

Conclusions:

• TCI propofol administration results in higher drug doses and deeper hypnosis, particularly in the early stages of anesthesia.
• The increased propofol administration with TCI systems primarily occurs within the first 30 minutes.
• BIS monitoring indicates a deeper hypnotic state with TCI, though clinical recovery endpoints are unaffected.