title: Factors affecting 13C-natural abundance measurement of breath carbon dioxide during surgery: absorption of carbon dioxide during endoscopic procedures.
abstract: The aim of this paper is to review the factors which may affect breath (13)CO(2)/(12)CO(2) natural abundance in patients undergoing surgery or intensive care. Intravenous glucose administration is a major determinant of the (13)CO(2)/(12)CO(2) of breath as intravenous glucose preparations are almost all derived from cornstarch. In addition, the oxidation of endogenous substrates can affect the (13)CO(2)/(12)CO(2) ratio. During many endoscopic procedures, such as laparoscopic surgery, carbon dioxide insufflation is used to provide a working space. As medical CO(2) is relatively depleted in (13)CO(2) compared with endogenous and exogenous metabolic CO(2) sources, breath (13)CO(2)/(12)CO(2) measurements can be used to estimate CO(2) absorption during these procedures. However, all these factors may also be affected by the bicarbonate pool, making a definitive attribution of changes in breath (13)CO(2)/(12)CO(2) to a single factor problematic.
authors.affiliation: Department of Surgery, Institute of Child Health and Great Ormond Street Hospital for Children, London, UK. s.eaton@ich.ucl.ac.uk
authors.forename: Simon
authors.initials: S
authors.lastname: Eaton
authors.forename: Maurizio
authors.initials: M
authors.lastname: Pacilli
authors.forename: James
authors.initials: J
authors.lastname: Wood
authors.forename: Merrill
authors.initials: M
authors.lastname: McHoney
authors.forename: Lucia
authors.initials: L
authors.lastname: Corizia
authors.forename: Charlotte
authors.initials: C
authors.lastname: Kingsley
authors.forename: Joseph I
authors.initials: JI
authors.lastname: Curry
authors.forename: Jane
authors.initials: J
authors.lastname: Herod
authors.forename: Ralph
authors.initials: R
authors.lastname: Cohen
authors.forename: Agostino
authors.initials: A
authors.lastname: Pierro
mesh_terms: D000042:Absorption; D001944:Breath Tests / Q000379:methods; D002245:Carbon Dioxide / Q000737:chemistry / Q000493:pharmacokinetics*; D002247:Carbon Isotopes; D004724:Endoscopy; D006801:Humans; D013058:Mass Spectrometry / Q000379:methods
chemical_list: D002247:Carbon Isotopes; D002245:Carbon Dioxide