title: Peripheral venous and arterial blood gas analysis in adults: are they comparable? A systematic review and meta-analysis.
abstract: Peripheral venous blood gas (PVBG) analysis is increasingly being used as a substitute for arterial blood sampling; however, comparability has not been clearly established. To determine if the pH, PCO2 and PO2 obtained from PVBG analysis is comparable with arterial blood gas (ABG) analysis. A search was conducted of electronic databases as well as hand-searching of journals and reference lists through December 2012 to identify studies comparing PVBG with ABG analysis in adult subjects. A systematic review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. A meta-analysis using a random effects model was used to calculate the average difference (bias) and the limits of agreement for the venous and arterial pH, PCO2 and PO2 . A total of 18 studies comprising 1768 subjects were included in the meta-analysis. There was considerable heterogeneity between studies with I(2) approaching 100%. There was little difference between the pH obtained from the PVBG and the ABG, with the arterial pH typically 0.03 higher than the venous pH (95% confidence interval 0.029-0.038). The venous and arterial PCO2 were not comparable because the 95% prediction interval of the bias for venous PCO2 was unacceptably wide, extending from -10.7 mm Hg to +2.4 mm Hg. The PO2 values compared poorly, the arterial PO2 typically 36.9 mm Hg greater than the venous with significant variability (95% confidence interval from 27.2 to 46.6 mm Hg). PVBG analysis compares well with ABG analysis for pH estimations in adults but not to the PCO2 or PO2 . These differences are sufficiently large to be of clinical significance.
authors.affiliation: Department of Respiratory Medicine, Prince of Wales Hospital, Randwick, NSW, Australia.
authors.forename: Anthony L
authors.initials: AL
authors.lastname: Byrne
authors.affiliation: Wales Anaesthesia, Prince of Wales Hospital, Randwick, NSW, Australia.|Faculty of Medicine, University of New South Wales, Sydney, NSW, Australia.
authors.forename: Michael
authors.initials: M
authors.lastname: Bennett
authors.affiliation: Faculty of Medicine, University of New South Wales, Sydney, NSW, Australia.
authors.forename: Robindro
authors.initials: R
authors.lastname: Chatterji
authors.affiliation: Faculty of Medicine, University of New South Wales, Sydney, NSW, Australia.
authors.forename: Rebecca
authors.initials: R
authors.lastname: Symons
authors.affiliation: Department of Anesthesiology, School of Medicine, University of Utah, Salt Lake City, UT, USA.
authors.forename: Nathan L
authors.initials: NL
authors.lastname: Pace
authors.affiliation: Department of Respiratory Medicine, Prince of Wales Hospital, Randwick, NSW, Australia.|Inflammation and Infection Research Centre (IIRC), Faculty of Medicine, University of New South Wales, Sydney, NSW, Australia.
authors.forename: Paul S
authors.initials: PS
authors.lastname: Thomas
mesh_terms: D000328:Adult; D001784:Blood Gas Analysis; D002245:Carbon Dioxide / Q000097:blood*; D006801:Humans; D008991:Monitoring, Physiologic / Q000379:methods*; D010100:Oxygen / Q000097:blood*; D012120:Respiration Disorders / Q000097:blood / Q000175:diagnosis*
chemical_list: D002245:Carbon Dioxide; D010100:Oxygen
keywords: arterial; carbon dioxide; meta-analysis; pH; venous