The use of venous blood gas in assessing arterial acid-base and oxygenation status - an analysis of aggregated data from multiple studies evaluating the venous to arterial conversion (v-TAC) method

Expert Rev Respir Med. 2024 Jul;18(7):553-559. doi: 10.1080/17476348.2024.2378021. Epub 2024 Jul 15.

Abstract

Background: Several methods exist to reduce the number of arterial blood gases (ABGs). One method, Roche v-TAC, has been evaluated in different patient groups. This paper aggregates data from these studies, in different patient categories using common analysis criteria.

Research design and methods: We included studies evaluating v-TAC based on paired arterial and peripheral venous blood samples. Bland-Altman analysis compared measured and calculated arterial values of pH, PCO2, and PO2. Subgroup analyses were performed for normal, chronic hypercapnia and chronic base excess, acute hyper- and hypocapnia, and acute and chronic base deficits.

Results: 811 samples from 12 studies were included. Bias and limits of agreement for measured and calculated values: pH 0.001 (-0.029 to 0.031), PCO2 -0.08 (-0.65 to 0.49) kPa, and PO2 0.04 (-1.71 to 1.78) kPa, with similar values for all sub-group analyses.

Conclusion: These data suggest that v-TAC analysis may have a role in replacing ABGs, avoiding arterial puncture. Substantial data exist in patients with chronic hypercapnia and chronic base excess, acute hyper- and hypocapnia, and in patients with relatively normal acid-base status, with similar bias and precision across groups and across study data. Limited data exist for patients with acute and chronic base deficits.

Keywords: Pulmonary medicine; emergency medicine; non-invasive ventilation; peripheral venous blood; respiratory and acid−base status.

MeSH terms

  • Acid-Base Equilibrium
  • Acid-Base Imbalance / blood
  • Acid-Base Imbalance / diagnosis
  • Acid-Base Imbalance / physiopathology
  • Arteries* / physiopathology
  • Blood Gas Analysis* / methods
  • Carbon Dioxide / blood
  • Humans
  • Hydrogen-Ion Concentration
  • Hypercapnia / blood
  • Hypercapnia / diagnosis
  • Hypercapnia / physiopathology
  • Oxygen* / blood
  • Predictive Value of Tests
  • Veins*

Substances

  • Oxygen
  • Carbon Dioxide