Desflurane pharmacokinetics during cardiopulmonary bypass

Area of Science:

• Anesthesiology
• Cardiovascular Surgery
• Pharmacokinetics

Background:

• Cardiopulmonary bypass (CPB) is a critical procedure in cardiac surgery.
• Understanding anesthetic pharmacokinetics during CPB is essential for patient management.
• Desflurane is an inhaled anesthetic agent with potential use during CPB.

Purpose of the Study:

• To characterize the wash-in and wash-out kinetics of desflurane.
• To evaluate desflurane's behavior when first administered during CPB.
• To assess desflurane pharmacokinetics at a core body temperature of 32°C.

Main Methods:

• A prospective, single-arm study was conducted in an operating room setting.
• Ten adult patients undergoing cardiac surgery were enrolled.
• Desflurane 6% was administered during CPB at 32°C, with serial blood sampling from arterial and venous lines, and oxygenator ports.

Main Results:

• Arterial desflurane concentrations rapidly reached 50% of inspired levels within 4 minutes during wash-in.
• At 32 minutes, arterial concentrations reached 68% of inspired levels (4.0% ± 0.3%).
• Arterial desflurane washout was rapid, falling to 18% of peak concentration within 4 minutes and 8% at 20 minutes post-discontinuation.

Conclusions:

• Desflurane demonstrates rapid initial wash-in and washout kinetics during cardiopulmonary bypass.
• The observed kinetics support the use of desflurane when initiated at 32°C and discontinued upon rewarming.
• These findings provide valuable pharmacokinetic data for desflurane use in cardiac surgery patients on CPB.