Roche v-TAC

Software application to calculate arterial blood gas values from venous blood

The new alternative to arterial sampling for blood gas measurement

Arterial blood gas is the gold standard for acid-base and blood gas testing in critical care. However, arterial punctures are complex, painful for the patient and come with a risk of side effects such as haematoma and infections.^1,2

Over the recent years there has been an increasing trend towards the use of venous blood, as it is more easily accessible and sample collection is less painful for the patient.³ While clinical parameters for acid-base measurements (pH, pCO₂ and bicarbonate) are largely similar between arterial and venous sampling, the venous measurement of oxygenation (pO₂, sO₂) is significantly different and therefore limits its use.⁴

Roche v-TAC software helps to overcome these limitations.

Arterial blood gas values from a venous blood sample

Roche v-TAC software calculates arterial blood gas (ABG) values from venous peripheral blood gas measurement, combined with arterial oxygen saturation (SpO₂), measured by a pulse oximeter.

The precision of the v-TAC calculated values is comparable to that of repeated ABG values for blood gas parameters, including pH, pCO₂, pO₂ (up to 10 kPa), HCO₃ and base excess (BE).⁵

Roche v-TAC may contribute to clinical, workflow and patient benefits

Roche v-TAC brochure

Enable workflow improvements with easy access to blood gas testing⁶

Transfer the task of blood gas testing from doctor/specialist to other staff groups, such as nurses⁶

Improve the speed of providing blood gas values for timely patient monitoring that may reduce the length of stay and improve clinical compliance⁷

Combine blood sampling for venous blood gas with routine blood sampling to decrease the need for separate punctures⁶

Reduce the need for painful arterial blood samples and potential side effects⁶

How does it work?

It is very simple to operate Roche v-TAC in daily clinical practice. The software can be used with the cobas b 123 POC system (configurations 3 and 4) and cobas b 221 system from Roche. Additionally, it can work seamlessly with blood gas analyzers from other leading manufacturers.

After implementation, the operational workflow is as follows:

Collect the venous blood sample for blood gas analysis and the corresponding SpO₂
Select v-TAC on the blood gas analyser to activate conversion to arterial values and enter the SpO₂ value
The v-TAC software calculates the arterial blood gas values which instantly become available to the clinician

Roche v-TAC revolutionises blood gas testing to help fight COVID-19

Learn how Roche v-TAC can help guide timely clinical decisions for COVID-19 patients.

Abbreviations

HCO₃: bicarbonate; kPa: kilopascal; pH: power of hydrogen; pCO₂: partial pressure of carbon dioxide; pO₂: partial pressure of oxygen; POC: point of care

References

Word Health Organisation. (2010. Article available from https://www.ncbi.nlm.nih.gov/books/NBK138661/ [Accessed May 2020]
Hambsch ZJ, Mitchell BS, Kerfeld J et al. (2015) Clin Transl Sci 8, 857–870
McKeever TM, Hearson G, Housley G, et al. (2016). Thorax 71, :210-215
Byrne AL, Bennett M, Chatterji R, et al. (2014). Respirology 19, 168-175
Toftegaard M, Rees SE, Andreassen S. (2009) Emerg Med J 26, 268-272
Ekström, M, et al. Calculated arterial blood gas values from a venous sample and pulse oximetry: Clinical validation. PLoS ONE. 2019, 14(4):e0215413.
Kamparis P, et al. Optimizing acute non-invasive ventilation care in the NHS; the v-TAC approach. Thorax 2018

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