title: Adherence of volatile propofol to various types of plastic tubing.
abstract: Propofol is an intravenous anesthetic. Currently, it is not possible to routinely measure blood concentration of the drug in real time. However, multi-capillary column ion-mobility spectrometry of exhaled gas can estimate blood propofol concentration. Unfortunately, adhesion of volatile propofol on plastic materials complicates measurements. Therefore, it is necessary to consider the extent to which volatile propofol adheres to various plastics used in sampling tubing. Perfluoralkoxy (PFA), polytetrafluorethylene (PTFE), polyurethane (PUR), silicone, and Tygon tubing were investigated in an experimental setting using a calibration gas generator (HovaCAL). Propofol gas was measured for one hour at 26 °C, 50 °C, and 90 °C tubing temperature. Test tubing segments were then flushed with N2to quantify desorption. PUR and Tygon sample tubing absorbed all volatile propofol. The silicone tubing reached the maximum propofol concentration after 119 min which was 29 min after propofol gas exposure stopped. The use of PFA or PTFE tubing produced comparable and reasonably accurate propofol measurements. The desaturation time for the PFA was 10 min shorter at 26 °C than for PTFE. PFA tubing thus seems most suitable for measurement of volatile propofol, with PTFE as an alternative.
authors.affiliation: Center of Breath Research, Department of Anaesthesiology, Intensive Care and Pain Therapy, Saarland University Medical Center and Saarland University Faculty of Medicine, Building 57, D-66421 Homburg, Germany.
authors.forename: F
authors.initials: F
authors.lastname: Maurer
authors.forename: D J
authors.initials: DJ
authors.lastname: Lorenz
authors.forename: G
authors.initials: G
authors.lastname: Pielsticker
authors.forename: T
authors.initials: T
authors.lastname: Volk
authors.forename: D I
authors.initials: DI
authors.lastname: Sessler
authors.forename: J I
authors.initials: JI
authors.lastname: Baumbach
authors.forename: S
authors.initials: S
authors.lastname: Kreuer
mesh_terms: D000268:Adhesiveness; D018686:Anesthetics, Intravenous / Q000032:analysis; D019540:Area Under Curve; D002138:Calibration; D010969:Plastics / Q000737:chemistry*; D015742:Propofol / Q000032:analysis*; D012815:Signal Processing, Computer-Assisted; D013696:Temperature; D013997:Time Factors; D014835:Volatilization
chemical_list: D018686:Anesthetics, Intravenous; D010969:Plastics; D015742:Propofol