title: Validation of a novel method for continuous saline tonometry in a porcine model.
abstract: Only intermittent and semi-continuous tonometric measurement of gastric and intestinal pHi is possible with the equipment available today. Earlier we developed a system for continuous saline tonometry and tested it in vitro. To assess the in vivo reliability of this method for continuous gastrointestinal saline tonometry, a standard tonometer for measurement of intestinal pCO2 and corresponding pHi was modified to allow continuous perfusion of physiological saline in a closed system and tested in a porcine model. In 11 anaesthetized and haemodynamically stable pigs, two continuous tonometry balloons were inserted into the distal small bowel, and a standard tonometry balloon was used as reference. To test long-term function of the continuous tonometers the research protocol lasted for eight hours. The two continuous saline tonometers performed well, and after an equilibration time of three hours the mean pHi values were stable between 7.35 and 7.43 and between 7.32 and 7.39 respectively. The standard tonometer measured stable pHi values. These preliminary studies indicate that continuous saline tonometry performs well over eight hours with a small bias and a good precision.
authors.affiliation: Department of Surgical and Perioperative Science, Surgery, Umeå University Hospital, Sweden.
authors.forename: R
authors.initials: R
authors.lastname: Fröjse
authors.forename: B
authors.initials: B
authors.lastname: Hedberg
authors.forename: T
authors.initials: T
authors.lastname: Bäcklund
authors.lastname: Lindahl
authors.forename: M
authors.initials: M
authors.lastname: Häggström
authors.forename: K A
authors.initials: KA
authors.lastname: Angquist
authors.forename: C
authors.initials: C
authors.lastname: Arnerlöv
mesh_terms: D000818:Animals; D005744:Gastric Acid; D006439:Hemodynamics / Q000502:physiology; D006863:Hydrogen-Ion Concentration; D066298:In Vitro Techniques; D008365:Manometry / Q000379:methods* / Q000592:standards; D023421:Models, Animal; D008991:Monitoring, Physiologic / Q000379:methods* / Q000592:standards; D012965:Sodium Chloride; D013270:Stomach / Q000502:physiology*; D013552:Swine
chemical_list: D012965:Sodium Chloride