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Results Klinikum Fürth clinical study presented at the DGP 2018 Dresden

On the 15th March 2018, the results from the v-TAC clinical study under the title: “Validity and clinical use of mathematical arterialized venous blood gas with the v-TAC approach for evaluation of arterial blood gas in patients with respiratory compromise” was presented by PD Dr. med. H Rittger and Dr. med. AC Klein.

The study demonstrates not only the v-TAC performance vs arterial blood gas, but also for comparison the performance of capillary blood gas vs arterial blood gas on a selected cohort of the patients. Here is the summary of the study with results:

Authors: AC Klein Klinik für Herz- und Lungenerkrankungen, Klinikum Fürth, H Rittger Klinik für Herz- und Lungenerkrankungen, Klinikum Fürth



Arterial Blood Gas (ABG) is gold standard to assess acid-base and blood gas status for patients with severe respiratory compromise, such as COPD patients during exacerbation, to assess progression of illness and response to treatment, using pH, pCO2 and pO2 as the measure. Capillary blood gas (CBG) is widely accepted as a more patient friendly and less invasive substitute for ABG.

A new method, named v-TAC, has become available for clinical use. v-TAC calculates arterial acid-base and blood gas values from a peripheral venous blood gas (VBG) measurement, combined with an oxygen saturation measurement (SpO2) from a pulse oximeter.

The purpose of this project is to study if the v-TAC method is a potential substitute for ABG and CBG for patients with respiratory compromise in an internal medicine department.



We performed a prospective study with a total of 93 patients with severe respiratory failure. 32 were undergoing ventilation treatment in the ICU, of them 26 were intubated. 61 were selected from the ward. An ABG and a VBG with corresponding oxygen sat measurement were taken simultaneously as convenience samples. For comparison, and in combination with the ABG and VBG, a CBG was also measured on 37 patients from the ward. All samples were analysed as quickly as possible on the same blood gas analyser. The results were analysed using Bland-Altman plots and statistical methods.



R2, Bias and ± 95% Limits of agreement for v-TAC vs. CBG respectively was: pH 92.4%, 0.004 ± 0.036 vs. 79.3%, -0.003 ± 0.042; pCO2 95%, -1.16 ± 4.64 mmHg vs. 89.3%, 0.02 ± 4.75 mmHg; pO2 N/A, 0.69 ± 12.7 mmHg vs. N/A, 5.8 ± 17.3 mmHg.


For figures and plots, please see abstract results here or contact OBI Medical.