title: Development and in vitro validation of a device for measuring non-shunt cardiac output by nitrous oxide throughflow.
abstract: A system has been developed for measuring non-shunt cardiac output by the throughflow technique, using nitrous oxide in patients undergoing general anaesthesia. The throughflow measurement technique is a non-invasive method based on inert gas throughflow theory. In vitro validation of the measurement system was performed using a lung gas exchange simulator. The accuracy and precision of the throughflow measurement system was assessed by comparing measured and target values for five simulated values of non-shunt cardiac output, from 2.88 to 9.86 l min(-1). This showed an overall mean bias of -0.031 min(-1) (range -0.00 to -0.101 min(-1)), with a mean coefficient of variation of the difference of 1.39% (1.20-1.93%). These results indicate that the measurement system is suitable for monitoring the non-shunt cardiac output in patients undergoing general anaesthesia using nitrous oxide throughflow.
authors.affiliation: Department of Electronic Engineering, La Trobe University, Bundoora, Victoria, Australia.
authors.forename: G M
authors.initials: GM
authors.lastname: Vartuli
authors.forename: R B
authors.initials: RB
authors.lastname: Burfoot
authors.forename: G J B
authors.initials: GJ
authors.lastname: Robinson
authors.forename: P J
authors.initials: PJ
authors.lastname: Peyton
authors.forename: P A
authors.initials: PA
authors.lastname: Junor
mesh_terms: D018685:Anesthetics, Inhalation / Q000493:pharmacokinetics*; D002302:Cardiac Output; D006801:Humans; D016343:Monitoring, Intraoperative / Q000379:methods*; D009609:Nitrous Oxide / Q000493:pharmacokinetics*; D011659:Pulmonary Gas Exchange
chemical_list: D018685:Anesthetics, Inhalation; D009609:Nitrous Oxide