AUTHOR=Tan Ratna N. G. B. , Pauws Steffen C. , van Loon Evelyne , Smits Vivanne E. H. J. , Lopriore Enrico , te Pas Arjan B. 

TITLE=Correlation and Interchangeability of Venous and Capillary Blood Gases in Non-Critically Ill Neonates

JOURNAL=Frontiers in Pediatrics

VOLUME=6

YEAR=2018

URL=https://www.frontiersin.org/journals/pediatrics/articles/10.3389/fped.2018.00089

DOI=10.3389/fped.2018.00089

ISSN=2296-2360

ABSTRACT=<sec id="ST1"><title>Background</title><p>Venous blood gas (VBG) is frequently used in the neonatal unit as alternative for capillary blood gas (CBG). However, studies reporting correlation are conflicting and data on interchangeability in neonates are lacking.</p></sec><sec id="ST2"><title>Objective</title><p>We investigated the correlation and interchangeability of the components between VBG and CBG in infants admitted to the neonatal intensive care unit.</p></sec><sec id="ST3"><title>Methods</title><p>In a prospective study in the neonatal unit in Leiden University Medical Center (Netherlands), simultaneously VBG and CBG were withdrawn in neonates when both venous puncture and intravenous access as blood gas monitoring was indicated. From each blood gas analysis, a Pearson correlation, intraclass correlation, and Bland–Altman analysis was performed. Clinically acceptable difference for each blood gas value was defined up-front by means of an absolute difference: pH ± 0.05; partial pressure of carbon dioxide (pCO<sub>2</sub>) (±0.67 kPa = 5 mmHg); partial pressure of oxygen (pO<sub>2</sub>) (±0.67 kPa = 5 mmHg); base excess ± 3 mmol/l; and bicarbonate (HCO<sub>3</sub><sup>−</sup>) ± 3 mmol/l.</p></sec><sec id="ST4"><title>Results</title><p>In 93 patients [median gestational age 31 (IQR 29–34) weeks], 193 paired samples of VBG and CBG were collected. The Pearson correlation between VBG and CBG was very strong for pH (<italic>r</italic> = 0.79; <italic>P</italic> &lt; 0.001), BE (<italic>r</italic> = 0.90; <italic>P</italic> &lt; 0.001) and bicarbonate (<italic>r</italic> = 0.87; <italic>P</italic> &lt; 0.001); strong for pCO<sub>2</sub> (<italic>r</italic> = 0.68; <italic>P</italic> &lt; 0.001); and moderate for pO<sub>2</sub> (<italic>r</italic> = 0.31; <italic>P</italic> &lt; 0.001). The percentage of the interchangeability within our acceptable absolute difference for pH was 88%, pCO<sub>2</sub> 72%, pO<sub>2</sub> 55%, BE 90%, and bicarbonate 94%.</p></sec><sec id="ST5"><title>Conclusion</title><p>VBG and CBG in neonates are well correlated and mostly interchangeable, except for pO<sub>2</sub>.</p></sec>