{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,23]],"date-time":"2026-09-23T15:08:54Z","timestamp":1790176134203,"version":"4.1.0"},"reference-count":13,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2026,9,23]],"date-time":"2026-09-23T00:00:00Z","timestamp":1790121600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Pediatr."],"abstract":"<jats:sec>\n                    <jats:title>Background<\/jats:title>\n                    <jats:p>Transcutaneous carbon dioxide (tcPCO\u2082) monitoring enables continuous non-invasive assessment of ventilation in neonates, but local tissue conditions may contribute to disagreement between tcPCO\u2082 and arterial PaCO\u2082 measurements. We explored within-patient temporal co-variation among radiographic chest-wall thickness, sensor heating power, and the discrepancy between tcPCO\u2082 and arterial PaCO\u2082 in a critically ill neonate.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Methods<\/jats:title>\n                    <jats:p>We conducted an exploratory single-patient longitudinal case study over 28 days. Serial measurements of tcPCO\u2082, arterial PaCO\u2082, radiographic chest-wall thickness ratio (%skin), an unvalidated radiographic measure explored as a potential surrogate of tissue edema, sensor heating power, and daily fluid balance were evaluated. Both the signed difference (tcPCO\u2082\u2212PaCO\u2082) and absolute difference |tcPCO\u2082\u2212PaCO\u2082| were summarized descriptively. Temporal trajectories and within-patient associations were explored with attention to serial dependence and shared time trends.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>\n                      Increasing radiographic chest-wall thickness coincided with greater tcPCO\u2082\u2013PaCO\u2082 discrepancy and higher sensor heating power. The three variables showed broadly similar rise-and-fall temporal trajectories. Unadjusted within-patient correlations were strong (\n                      <jats:italic>r<\/jats:italic>\n                      \u2009=\u20090.766\u20130.813), and residual correlations persisted but were attenuated after removal of the quadratic Day\/Day\n                      <jats:sup>2<\/jats:sup>\n                      trend (residual\n                      <jats:italic>r<\/jats:italic>\n                      \u2009=\u20090.545\u20130.625). These residual correlations were interpreted descriptively and not as evidence of a time-independent relationship. PCA identified a dominant principal component explaining 85.9% of total variance, descriptively summarizing shared temporal covariance among radiographic chest-wall thickness, sensor heating power, and tcPCO\u2082\u2013PaCO\u2082 discrepancy.\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusion<\/jats:title>\n                    <jats:p>In this single-patient longitudinal case study, radiographic chest-wall thickness, sensor heating power, and tcPCO\u2082\u2013PaCO\u2082 discrepancy showed parallel temporal changes. These findings generate the hypothesis that changes in local tissue conditions associated with increased radiographic chest-wall thickness may contribute to tcPCO\u2082\u2013PaCO\u2082 disagreement, but causal inference is not possible and validation in multi-patient studies is required.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.3389\/fped.2026.1887546","type":"journal-article","created":{"date-parts":[[2026,9,23]],"date-time":"2026-09-23T14:40:42Z","timestamp":1790174442000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":0,"title":["Longitudinal co-variation of radiographic chest-wall thickness and transcutaneous\u2013arterial CO\u2082 discrepancy in congenital diaphragmatic hernia: a single-patient case study"],"prefix":"10.3389","volume":"14","author":[{"given":"Tomonori","family":"Kurimoto","sequence":"first","affiliation":[{"name":"Department of Pediatric Cardiology, National Cerebral and Cardiovascular Center","place":["Suita-shi, Osaka, Japan"]},{"name":"Department of Neonatology, Perinatal Medical Center, Kagoshima City Hospital","place":["Kagoshima, Japan"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Eiji","family":"Hirakawa","sequence":"additional","affiliation":[{"name":"Department of Neonatology, Perinatal Medical Center, Kagoshima City Hospital","place":["Kagoshima, Japan"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Hiroshi","family":"Ohashi","sequence":"additional","affiliation":[{"name":"Department of Neonatology, Perinatal Medical Center, Kagoshima City Hospital","place":["Kagoshima, Japan"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Takuya","family":"Tokuhisa","sequence":"additional","affiliation":[{"name":"Department of Neonatology, Perinatal Medical Center, Kagoshima City Hospital","place":["Kagoshima, Japan"]}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1965","published-online":{"date-parts":[[2026,9,23]]},"reference":[{"key":"B1","doi-asserted-by":"publisher","first-page":"CD011494","DOI":"10.1002\/14651858.CD011494.pub2","article-title":"Transcutaneous carbon dioxide monitoring for the prevention of neonatal morbidity and mortality","volume":"2","author":"Bruschettini","year":"2016","journal-title":"Cochrane Database Syst Rev"},{"key":"B2","doi-asserted-by":"publisher","first-page":"90","DOI":"10.4187\/respcare.04212","article-title":"Neonatal transcutaneous carbon dioxide monitoring\u2014effect on clinical management and outcomes","volume":"61","author":"Mukhopadhyay","year":"2016","journal-title":"Respir Care"},{"key":"B3","doi-asserted-by":"publisher","first-page":"e2020000570","DOI":"10.1542\/peds.2020-000570","article-title":"An initiative to decrease laboratory testing in a 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