TY - JOUR
T1 - Comparison of mathematically arterialised venous blood gas sampling with arterial, capillary, and venous sampling in adult patients with hypercapnic respiratory failure
T2 - a single-centre longitudinal cohort study
AU - Davies, Michael Gordon
AU - Wozniak, Dariusz Rafal
AU - Quinnell, Timothy George
AU - Palas, Earl
AU - George, Susan
AU - Huang, Yingchang
AU - Jayasekara, Ruwanthi
AU - Stoneman, Victoria
AU - Smith, Ian Edward
AU - Thomsen, Lars Pilegaard
AU - Rees, Stephen Edward
N1 - © Author(s) (or their employer(s)) 2023. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.
PY - 2023/6/27
Y1 - 2023/6/27
N2 - Background Accurate arterial blood gas (ABG) analysis is essential in the management of patients with hypercapnic respiratory failure, but repeated sampling requires technical expertise and is painful. Missed sampling is common and has a negative impact on patient care. A newer venous to arterial conversion method (v-TAC, Roche) uses mathematical models of acid-base chemistry, a venous blood gas sample and peripheral blood oxygen saturation to calculate arterial acid-base status. It has the potential to replace routine ABG sampling for selected patient cohorts. The aim of this study was to compare v-TAC with ABG, capillary and venous sampling in a patient cohort referred to start non-invasive ventilation (NIV). Methods Recruited patients underwent near simultaneous ABG, capillary blood gas (CBG) and venous blood gas (VBG) sampling at day 0, and up to two further occasions (day 1 NIV and discharge). The primary outcome was the reliability of v-TAC sampling compared with ABG, via Bland-Altman analysis, to identify respiratory failure (via PaCO 2) and to detect changes in PaCO 2 in response to NIV. Secondary outcomes included agreements with pH, sampling success rates and pain. Results The agreement between ABG and v-TAC/venous PaCO 2 was assessed for 119 matched sampling episodes and 105 between ABG and CBG. Close agreement was shown for v-TAC (mean difference (SD) 0.01 (0.5) kPa), but not for CBG (-0.75 (0.69) kPa) or VBG (+1.00 (0.90) kPa). Longitudinal data for 32 patients started on NIV showed the closest agreement for ABG and v-TAC (R 2 =0.61). v-TAC sampling had the highest first-time success rate (88%) and was less painful than arterial (p<0.0001). Conclusion Mathematical arterialisation of venous samples was easier to obtain and less painful than ABG sampling. Results showed close agreement for PaCO2 and pH and tracked well longitudinally such that the v-TAC method could replace routine ABG testing to recognise and monitor patients with hypercapnic respiratory failure. Trial registration number NCT04072848; www.clinicaltrials.gov.
AB - Background Accurate arterial blood gas (ABG) analysis is essential in the management of patients with hypercapnic respiratory failure, but repeated sampling requires technical expertise and is painful. Missed sampling is common and has a negative impact on patient care. A newer venous to arterial conversion method (v-TAC, Roche) uses mathematical models of acid-base chemistry, a venous blood gas sample and peripheral blood oxygen saturation to calculate arterial acid-base status. It has the potential to replace routine ABG sampling for selected patient cohorts. The aim of this study was to compare v-TAC with ABG, capillary and venous sampling in a patient cohort referred to start non-invasive ventilation (NIV). Methods Recruited patients underwent near simultaneous ABG, capillary blood gas (CBG) and venous blood gas (VBG) sampling at day 0, and up to two further occasions (day 1 NIV and discharge). The primary outcome was the reliability of v-TAC sampling compared with ABG, via Bland-Altman analysis, to identify respiratory failure (via PaCO 2) and to detect changes in PaCO 2 in response to NIV. Secondary outcomes included agreements with pH, sampling success rates and pain. Results The agreement between ABG and v-TAC/venous PaCO 2 was assessed for 119 matched sampling episodes and 105 between ABG and CBG. Close agreement was shown for v-TAC (mean difference (SD) 0.01 (0.5) kPa), but not for CBG (-0.75 (0.69) kPa) or VBG (+1.00 (0.90) kPa). Longitudinal data for 32 patients started on NIV showed the closest agreement for ABG and v-TAC (R 2 =0.61). v-TAC sampling had the highest first-time success rate (88%) and was less painful than arterial (p<0.0001). Conclusion Mathematical arterialisation of venous samples was easier to obtain and less painful than ABG sampling. Results showed close agreement for PaCO2 and pH and tracked well longitudinally such that the v-TAC method could replace routine ABG testing to recognise and monitor patients with hypercapnic respiratory failure. Trial registration number NCT04072848; www.clinicaltrials.gov.
KW - Adult
KW - Carbon Dioxide
KW - Cohort Studies
KW - Humans
KW - Longitudinal Studies
KW - Reproducibility of Results
KW - Respiratory Insufficiency/diagnosis
KW - Assisted Ventilation
KW - Non invasive ventilation
KW - Respiratory Measurement
UR - http://www.scopus.com/inward/record.url?scp=85164209903&partnerID=8YFLogxK
U2 - 10.1136/bmjresp-2022-001537
DO - 10.1136/bmjresp-2022-001537
M3 - Journal article
C2 - 37369550
SN - 2052-4439
VL - 10
JO - BMJ open respiratory research
JF - BMJ open respiratory research
IS - 1
M1 - e001537
ER -