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Calculated arterial blood gas values from a venous sample and pulse oximetry : Clinical validation

Ekström, Magnus LU ; Engblom, Anna; Ilic, Adam; Holthius, Nicholas; Nordström, Peter and Vaara, Ivar (2019) In PLoS ONE 14(4).
Abstract


Background Arterial blood gases (ABG) are essential for assessment of patients with severe illness, but sampling is difficult in some settings and more painful than for peripheral venous blood gas (VBG). Venous to Arterial Conversion (v-TAC; OBIMedical ApS, Denmark) is a method to calculate ABG values from a VBG and pulse oximetry (SpO
2
). The aim was to validate v-TAC against ABG for measuring pH, carbon dioxide (pCO
2
... (More)


Background Arterial blood gases (ABG) are essential for assessment of patients with severe illness, but sampling is difficult in some settings and more painful than for peripheral venous blood gas (VBG). Venous to Arterial Conversion (v-TAC; OBIMedical ApS, Denmark) is a method to calculate ABG values from a VBG and pulse oximetry (SpO
2
). The aim was to validate v-TAC against ABG for measuring pH, carbon dioxide (pCO
2
) and oxygenation (pO
2
). Methods Of 103 sample sets, 87 paired ABGs and VBGs with SpO
2
from 46 inpatients eligible for ABG met strict sampling criteria. Agreement was evaluated using mean difference with 95% limits of agreement (LoA) and Bland-Altman plots. Results v-TAC had very high agreement with ABG for pH (mean diff
(ABG–v-TAC)
-0.001; 95% LoA -0.017 to 0.016), pCO
2
(-0.14 kPa; 95% LoA -0.46 to 0.19) and moderate to high for pO
2
(-0.28 kPa; 95% LoA -1.31 to 0.76). For detecting hypercapnia (PaCO
2
>6.0 kPa), v-TAC had sensitivity 100%, specificity 93.8% and accuracy 97%. The accuracy of v-TAC for detecting hypoxemia (PaO
2
<8.0 kPa) was comparable to that of pulse oximetry. Agreement with ABG was higher for v-TAC than for VBG for all analyses. Conclusion Calculated arterial blood gases (v-TAC) from a venous sample and pulse oximetry were comparable to ABG values and may be useful for evaluation of blood gases in clinical settings. This could reduce the logistic burden of arterial sampling, facilitate improved screening and follow-up and reduce patient pain.

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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
PLoS ONE
volume
14
issue
4
publisher
Public Library of Science
external identifiers
  • scopus:85064355790
ISSN
1932-6203
DOI
10.1371/journal.pone.0215413
language
English
LU publication?
yes
id
85e00e58-fab0-4de7-955a-7ac4bbb81061
date added to LUP
2019-05-03 13:03:46
date last changed
2019-05-21 04:22:00
@article{85e00e58-fab0-4de7-955a-7ac4bbb81061,
  abstract     = {<p><br>
                                                         Background Arterial blood gases (ABG) are essential for assessment of patients with severe illness, but sampling is difficult in some settings and more painful than for peripheral venous blood gas (VBG). Venous to Arterial Conversion (v-TAC; OBIMedical ApS, Denmark) is a method to calculate ABG values from a VBG and pulse oximetry (SpO                             <br>
                            <sub>2</sub><br>
                                                         ). The aim was to validate v-TAC against ABG for measuring pH, carbon dioxide (pCO                             <br>
                            <sub>2</sub><br>
                                                         ) and oxygenation (pO                             <br>
                            <sub>2</sub><br>
                                                         ). Methods Of 103 sample sets, 87 paired ABGs and VBGs with SpO                             <br>
                            <sub>2</sub><br>
                                                          from 46 inpatients eligible for ABG met strict sampling criteria. Agreement was evaluated using mean difference with 95% limits of agreement (LoA) and Bland-Altman plots. Results v-TAC had very high agreement with ABG for pH (mean diff                             <br>
                            <sub>(ABG–v-TAC)</sub><br>
                                                          -0.001; 95% LoA -0.017 to 0.016), pCO                             <br>
                            <sub>2</sub><br>
                                                          (-0.14 kPa; 95% LoA -0.46 to 0.19) and moderate to high for pO                             <br>
                            <sub>2</sub><br>
                                                          (-0.28 kPa; 95% LoA -1.31 to 0.76). For detecting hypercapnia (PaCO                             <br>
                            <sub>2</sub><br>
                                                         &gt;6.0 kPa), v-TAC had sensitivity 100%, specificity 93.8% and accuracy 97%. The accuracy of v-TAC for detecting hypoxemia (PaO                             <br>
                            <sub>2</sub><br>
                                                         &lt;8.0 kPa) was comparable to that of pulse oximetry. Agreement with ABG was higher for v-TAC than for VBG for all analyses. Conclusion Calculated arterial blood gases (v-TAC) from a venous sample and pulse oximetry were comparable to ABG values and may be useful for evaluation of blood gases in clinical settings. This could reduce the logistic burden of arterial sampling, facilitate improved screening and follow-up and reduce patient pain.                         <br>
                        </p>},
  articleno    = {e0215413},
  author       = {Ekström, Magnus and Engblom, Anna and Ilic, Adam and Holthius, Nicholas and Nordström, Peter and Vaara, Ivar},
  issn         = {1932-6203},
  language     = {eng},
  month        = {04},
  number       = {4},
  publisher    = {Public Library of Science},
  series       = {PLoS ONE},
  title        = {Calculated arterial blood gas values from a venous sample and pulse oximetry : Clinical validation},
  url          = {http://dx.doi.org/10.1371/journal.pone.0215413},
  volume       = {14},
  year         = {2019},
}