title: A new method for measurement of anaesthetic partial pressure in blood.
abstract: We have developed a simple, reliable method for rapid analysis of the partial pressure of volatile anaesthetic agents, based on a two-stage, head-space analysis. It is designed to solve the problems associated with reduced solubility of modern anaesthetics. After equilibration and analysis of a 2-ml sample of blood at 37 degrees C, 1 ml is transferred to another vial for a second equilibration. This ensures that there is no vapour in the headspace before the second equilibration. Measurements were performed on human blood samples equilibrated with 1% sevoflurane, 2.5% isoflurane or 3% desflurane in a tonometer. The mean error in the sample measurements was -2.3% of the tonometer reading and the 95% confidence interval for an individual measurement was +/- 8.5%. Blood samples may be stored overnight without any significant change in the results.
authors.affiliation: Department of Anaesthesia, Hammersmith Hospital, London.
authors.forename: M A
authors.initials: MA
authors.lastname: Smith
authors.forename: S M
authors.initials: SM
authors.lastname: Sapsed-Byrne
authors.forename: G G
authors.initials: GG
authors.lastname: Lockwood
mesh_terms: D018685:Anesthetics, Inhalation / Q000097:blood*; D001800:Blood Specimen Collection / Q000379:methods; D002849:Chromatography, Gas; D000077335:Desflurane; D004987:Ethers / Q000097:blood; D006801:Humans; D007530:Isoflurane / Q000031:analogs & derivatives / Q000097:blood; D008738:Methyl Ethers; D010313:Partial Pressure; D000077149:Sevoflurane
chemical_list: D018685:Anesthetics, Inhalation; D004987:Ethers; D008738:Methyl Ethers; D000077149:Sevoflurane; D000077335:Desflurane; D007530:Isoflurane