{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,21]],"date-time":"2026-09-21T21:04:24Z","timestamp":1790024664458,"version":"4.0.1"},"reference-count":23,"publisher":"MDPI AG","issue":"7","license":[{"start":{"date-parts":[[2026,7,3]],"date-time":"2026-07-03T00:00:00Z","timestamp":1783036800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Children"],"abstract":"<jats:p>Background: Among infants undergoing cardiac surgery, AKI may affect as many as 40% of this population and carries an unfavorable prognosis. A range of contributors has been implicated, including early age, cyanotic physiology, and extended time on cardiopulmonary bypass (CPB). Nadir-indexed oxygen delivery (DO2) is an important determinant for early detection of hypoperfusion and anaerobic metabolism during CPB. This study aimed to explore the relationship between nadir DO2 during pediatric CPB and postoperative acute kidney injury. Methods: Between 1 October 2024 and 1 December 2024, we enrolled 40 children who underwent cardiac surgery with CPB [median age 6 months (IQR 4\u20138), median weight 5.5 kg (IQR 5\u20137 kg)] into an observational cohort. DO2 was tracked intraoperatively for every patient, and pre- as well as intraoperative variables were examined for independent links to AKI. Postoperative outcomes were then compared between patients who did and did not develop AKI. Results: In our patient population (n = 40), 16 patients (40%) developed AKI according to the pRIFLE criteria (75% risk; 18.7% injury; 6.2% failure; no patient was in the loss or end-stage renal disease categories). Lower nadir DO2 values were associated with postoperative AKI in this exploratory pilot cohort. ROC analysis identified an exploratory nadir DO2 threshold of 360 mL\/min\/m2 (sensitivity 70%, specificity 80%) associated with postoperative AKI. Because this threshold was both derived and evaluated within the same cohort without validation, it should be regarded only as a preliminary, hypothesis-generating observation with no implication of clinical applicability and requires validation in larger independent cohorts. Conclusions: In this exploratory pilot cohort, lower nadir DO2 during cardiopulmonary bypass was independently associated with postoperative AKI. An exploratory ROC-derived threshold of 360 mL\/min\/m2 was identified; however, this threshold should be considered hypothesis-generating rather than clinically validated. The consistency of findings across both dichotomous and continuous DO2 analyses strengthens the robustness of the observed association, although larger prospective studies are required to externally validate this threshold, which at present carries no implication of clinical applicability.<\/jats:p>","DOI":"10.3390\/children13070893","type":"journal-article","created":{"date-parts":[[2026,7,3]],"date-time":"2026-07-03T14:33:06Z","timestamp":1783089186000},"page":"893","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":1,"title":["Nadir Oxygen Delivery During Pediatric Cardiopulmonary Bypass and Postoperative Acute Kidney Injury: A Pilot Cohort Study"],"prefix":"10.3390","volume":"13","author":[{"ORCID":"https:\/\/orcid.org\/0009-0002-5360-7044","authenticated-orcid":false,"given":"Demet","family":"Kangel","sequence":"first","affiliation":[{"name":"Department of Pediatric Cardiology, University of Health Sciences, Basaksehir Cam and Sakura City Hospital, Istanbul 34480, Turkey"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4919-083X","authenticated-orcid":false,"given":"Burcu","family":"\u00c7evlik","sequence":"additional","affiliation":[{"name":"Department of Pediatric Cardiology, University of Health Sciences, Basaksehir Cam and Sakura City Hospital, Istanbul 34480, Turkey"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"\u0130ncila","family":"Ali","sequence":"additional","affiliation":[{"name":"Department of Anaesthesiology and Reanimation, University of Health Sciences, Basaksehir Cam and Sakura City Hospital, Istanbul 34480, Turkey"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5157-734X","authenticated-orcid":false,"given":"Ezgi Diren\u00e7","family":"Y\u00fccel","sequence":"additional","affiliation":[{"name":"Department of Anaesthesiology and Reanimation, University of Health Sciences, Basaksehir Cam and Sakura City Hospital, Istanbul 34480, Turkey"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Eymen","family":"Recep","sequence":"additional","affiliation":[{"name":"Department of Pediatric Cardiovascular Surgery, University of Health Sciences, Basaksehir Cam and Sakura City Hospital, Istanbul 34480, Turkey"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Tar\u0131k","family":"Demir","sequence":"additional","affiliation":[{"name":"Department of Pediatric Cardiovascular Surgery, University of Health Sciences, Basaksehir Cam and Sakura City Hospital, Istanbul 34480, Turkey"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ali Can","family":"Hatemi","sequence":"additional","affiliation":[{"name":"Department of Pediatric Cardiovascular Surgery, University of Health Sciences, Basaksehir Cam and Sakura City Hospital, Istanbul 34480, Turkey"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Erkut","family":"\u00d6zt\u00fcrk","sequence":"additional","affiliation":[{"name":"Department of Pediatric Cardiology, University of Health Sciences, Basaksehir Cam and Sakura City Hospital, Istanbul 34480, Turkey"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,7,3]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"1493","DOI":"10.1097\/CCM.0b013e31821201d3","article-title":"Incidence, risk factors, and outcomes of acute kidney injury after pediatric cardiacsurgery: A prospective multicenter study","volume":"39","author":"Li","year":"2011","journal-title":"Crit. Care Med."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"e15270","DOI":"10.1111\/ped.15270","article-title":"The comparison of three different acute kidney injury classification systems after congenital heart surgery","volume":"64","author":"Ozcanoglu","year":"2022","journal-title":"Pediatr. Int."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"99","DOI":"10.1016\/j.repc.2015.06.006","article-title":"Acute kidney injury after pediatric cardiac surgery: Risk factors and outcomes. Proposal for a predictive model","volume":"35","author":"Cardoso","year":"2016","journal-title":"Rev. Port. Cardiol."},{"key":"ref_4","first-page":"e7727","article-title":"Acute Kidney Injury after Congenital Heart Disease Surgery: A Single-Center Experience in a Low- to Middle-Income Country","volume":"12","author":"Ali","year":"2020","journal-title":"Cureus"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"647","DOI":"10.1016\/j.athoracsur.2021.01.026","article-title":"Nadir Oxygen Delivery During Pediatric Bypass as a Predictor of Acute Kidney Injury","volume":"113","author":"Zhang","year":"2022","journal-title":"Ann. Thorac. Surg."},{"key":"ref_6","first-page":"P2","article-title":"Variation in Measurement and Reporting of Goal Directed Perfusion Parameters","volume":"49","author":"Baker","year":"2017","journal-title":"J. Extra Corpor. Technol."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"702","DOI":"10.1053\/j.jvca.2024.11.017","article-title":"Oxygen Delivery During Cardiopulmonary Bypass in Pediatric Patients With Congenital Heart Disease: Association with Postoperative Acute Kidney Injury","volume":"39","author":"Taka","year":"2025","journal-title":"J. Cardiothorac. Vasc. Anesth."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"1505","DOI":"10.1016\/j.jtcvs.2022.05.039","article-title":"Oxygen delivery in pediatric cardiac surgery and its association with acute kidney injury using machine learning","volume":"165","author":"Hayward","year":"2023","journal-title":"J. Thorac. Cardiovasc. Surg."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"112","DOI":"10.1051\/ject\/2023029","article-title":"Indexed oxygen delivery during pediatric cardiopulmonary bypass is a modifiable risk factor for postoperative acute kidney injury","volume":"55","author":"Dreher","year":"2023","journal-title":"J. Extra Corpor. Technol."},{"key":"ref_10","first-page":"1","article-title":"Assessment of the factors that affect fast-track or early extubation following pediatric cardiac surgery","volume":"31","author":"Kahraman","year":"2023","journal-title":"Turk. Gogus Kalp Damar Cerrahisi Derg."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"2189","DOI":"10.1016\/j.athoracsur.2006.01.025","article-title":"Anaerobic metabolism during cardiopulmonary bypass: Predictive value of carbon dioxide derived parameters","volume":"81","author":"Ranucci","year":"2006","journal-title":"Ann. Thorac. Surg."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"110","DOI":"10.1067\/mtc.2002.119064","article-title":"Consensus-based method for risk adjustment for surgery for congenital heart disease","volume":"123","author":"Jenkins","year":"2002","journal-title":"J. Thorac. Cardiovasc. Surg."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"529","DOI":"10.1097\/PCC.0000000000000153","article-title":"Vasoactive-inotropic score is associated with outcome after infant cardiac surgery:an analysis from the Pediatric Cardiac Critical Care Consortium and Virtual PICU System Registries","volume":"15","author":"Gaies","year":"2014","journal-title":"Pediatr. Crit. Care Med."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"539","DOI":"10.1016\/j.anclin.2018.07.005","article-title":"Stratification and Risk Reduction of Perioperative Acute Kidney Injury: An Update","volume":"36","author":"Cole","year":"2018","journal-title":"Anesthesiol. Clin."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"1028","DOI":"10.1038\/sj.ki.5002231","article-title":"Modified RIFLE criteria in critically ill children with acute kidney injury","volume":"71","author":"Zappitelli","year":"2007","journal-title":"Kidney Int."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"1984","DOI":"10.1016\/j.athoracsur.2011.10.046","article-title":"Acute kidney injury is associated with higher morbidity and resource utilization in pediatric patients undergoing heart surgery","volume":"93","author":"Breuer","year":"2012","journal-title":"Ann. Thorac. Surg."},{"key":"ref_17","doi-asserted-by":"crossref","unstructured":"Park, S.K., Hur, M., Kim, E., Kim, W.H., Park, J.B., Kim, Y., Yang, J.H., Jun, T.G., and Kim, C.S. (2016). Risk Factors for Acute Kidney Injury after Congenital Cardiac Surgery in Infants and Children: A Retrospective Observational Study. PLoS ONE, 11.","DOI":"10.1371\/journal.pone.0166328"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"1185","DOI":"10.1111\/j.1460-9592.2011.03654.x","article-title":"Cystatin C: Influence of perfusion and myocardial injury on early (<24 h) renal function after pediatric cardiac surgery","volume":"21","author":"Vassalos","year":"2011","journal-title":"Paediatr. Anaesth."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"1741","DOI":"10.1038\/s41390-021-01654-9","article-title":"The lower threshold of hypothermic oxygen delivery to prevent neonatal acute kidney injury","volume":"91","author":"Zhang","year":"2022","journal-title":"Pediatr. Res."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"492","DOI":"10.1016\/j.jtcvs.2018.10.148","article-title":"Time-dose response of oxygen delivery during cardiopulmonary bypass predicts acute kidney injury","volume":"158","author":"Mukaida","year":"2019","journal-title":"J. Thorac. Cardiovasc. Surg."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"1290","DOI":"10.1111\/aas.13457","article-title":"Duration of critically low oxygen delivery is associated with acute kidney injury after cardiac surgery","volume":"63","author":"Rasmussen","year":"2019","journal-title":"Acta Anaesthesiol. Scand."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"395","DOI":"10.1016\/j.bja.2019.12.034","article-title":"Lower limit of adequate oxygen delivery for the maintenance of aerobic metabolism during cardiopulmonary bypass in neonates","volume":"124","author":"Bojan","year":"2020","journal-title":"Br. J. Anaesth."},{"key":"ref_23","first-page":"P8","article-title":"Is it Time for Goal-Directed Therapy in Perfusion","volume":"49","author":"Groom","year":"2017","journal-title":"J. Extra Corpor. Technol."}],"container-title":["Children"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2227-9067\/13\/7\/893\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,7,3]],"date-time":"2026-07-03T15:35:04Z","timestamp":1783092904000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2227-9067\/13\/7\/893"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,7,3]]},"references-count":23,"journal-issue":{"issue":"7","published-online":{"date-parts":[[2026,7]]}},"alternative-id":["children13070893"],"URL":"https:\/\/doi.org\/10.3390\/children13070893","relation":{},"ISSN":["2227-9067"],"issn-type":[{"value":"2227-9067","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,7,3]]}}}