Abstract
Objective
Ensuring adequate tissue perfusion during cardiopulmonary bypass is critical for preserving postoperative organ function. Acute kidney injury (AKI) is one of the most significant causes of morbidity and mortality after cardiac surgery. The relationship of carbon dioxide-associated parameters to renal dysfunction has not yet been sufficiently investigated. The aim of this study is to demonstrate the relationship between carbon dioxide-related parameters measured during cardiopulmonary bypass and postoperative renal function and AKI.
Materials and Methods
Our study included 50 patients aged 18 years and older who underwent coronary artery bypass grafting with cardiopulmonary bypass at the Cardiovascular Surgery Clinic of University of Health Sciences Türkiye, Bursa Yüksek İhtisas Training and Research Hospital between September and November 2025. Patients (those who developed AKI and those who did not) were divided into two groups. The necessary calculations were made using venous and arterial blood gas results obtained from patients at different times.
Results
According to the Kidney Disease: Improving Global Outcomes criteria, postoperative AKI developed in 34% of patients (n = 17) and did not develop in 66% (n = 33). No significant differences were found in demographic data between the two groups. No significant differences were found in demographic data between the two groups. In the study, pre-pump blood gas values showed that P(v-a) CO2 was significantly higher in the AKI (+) group. Furthermore, each unit increase in age was associated with an approximately 9.1% increase in the probability of developing AKI.
Conclusion
Cardiac surgery associated AKI increases in patients with advanced age and a higher incidence of comorbidities. We believe that the use of carbon dioxide-derived parameters during cardiopulmonary bypass may be useful in predicting the development of postoperative AKI. However, larger case series studies are needed to identify the causes of AKI and to test the reliability of these markers for early-stage kidney injury.
Keywords:
Cardiopulmonary bypass, carbondioxide-related parameters, acute renal injury, open heart surgery
References
1Karkouti K, Wijeysundera DN, Yau TM, Callum JL, Cheng DC, Crowther M, et al. Acute kidney injury after cardiac surgery: focus on modifiable risk factors. Circulation. 2009;119(4):495-502.
2Lassnigg A, Schmidlin D, Mouhieddine M, Bachmann LM, Druml W, Bauer P, et al. Minimal changes of serum creatinine predict prognosis in patients after cardiothoracic surgery: a prospective cohort study. J Am Soc Nephrol. 2004;15(6):1597-1605.
3Vives M, Wijeysundera D, Marczin N, Monedero P, Rao V. Cardiac surgery-associated acute kidney injury. Interact Cardiovasc Thorac Surg. 2014;18(5):637-645.
4Chen DX, Zhang YY, Xiong XL, Zhou L, Shi J. Association between intraoperative lactate levels and acute kidney injury after on-pump cardiac surgery: a retrospective cohort study across two centers. BMC Surg. 2025;25(1):324.
5Minton J, Sidebotham DA. Hyperlactatemia and cardiac surgery. J Extra Corpor Technol. 2017;49(1):7-15.
6Hessel EA 2nd. What’s new in cardiopulmonary bypass. J Cardiothorac Vasc Anesth. 2019;33(8):2296-2326.
7Renew JR, Barbara DW, Hyder JA, Dearani JA, Rivera M, Pulido JN. Frequency and outcomes of severe hyperlactatemia after elective cardiac surgery. J Thorac Cardiovasc Surg. 2016;151(3):825-830.
8Zhou XF, Yu RG, Chen Q, Xue YM, Chen H. Performance of lactate and CO 2 -derived parameters in predicting major postoperative complications after cardiac surgery with cardiopulmonary bypass: protocol of a diagnostic accuracy study. Front Cardiovasc Med. 2021;8:724713.
9Ltaief Z, Schneider AG, Liaudet L. Pathophysiology and clinical implications of the veno-arterial PCO 2 gap. Crit Care. 2021;25(1):318.
10Weisse AB. Cardiac surgery: a century of progress. Tex Heart Inst J. 2011;38(5):486-490.
11Chertow GM, Lazarus JM, Christiansen CL, Cook EF, Hammermeister KE, Grover F, et al. Preoperative renal risk stratification. Circulation. 1997;95(4):878-884.
12Patel UD, Garg AX, Krumholz HM, Shlipak MG, Coca SG, Sint K, et al. Preoperative serum brain natriuretic peptide and risk of acute kidney injury after cardiac surgery. Circulation. 2012;125(11):1347-1355.
13Kidher E, Harling L, Ashrafian H, Naase H, Chukwuemeka A, Anderson J, et al. Pulse wave velocity and neutrophil gelatinase-associated lipocalin as predictors of acute kidney injury following aortic valve replacement. J Cardiothorac Surg. 2014;9:89.
14Peco-Antić A, Ivanišević I, Vulićević I, Kotur-Stevuljević J, Ilić S, Ivanišević J, et al. Biomarkers of acute kidney injury in pediatric cardiac surgery. Clin Biochem. 2013;46(13-14):1244-1251.
15Bastin AJ, Ostermann M, Slack AJ, Diller GP, Finney SJ, Evans TW. Acute kidney injury after cardiac surgery according to risk/injury/failure/loss/end-stage, acute kidney injury network, and kidney disease: improving global outcomes classifications. J Crit Care. 2013;28(4):389-396.
16Zappitelli M, Bernier PL, Saczkowski RS, Tchervenkov CI, Gottesman R, Dancea A, et al. A small post-operative rise in serum creatinine predicts acute kidney injury in children undergoing cardiac surgery. Kidney Int. 2009;76(8):885-892.
17Su Y, Wang P, Hu Y, Liu WJ, Zhang YJ, Chen JQ, et al. AKI-Pro score for predicting progression to severe acute kidney injury or death in patients with early acute kidney injury after cardiac surgery. J Transl Med. 2024;22(1):571.
18GIBBON JH Jr. Application of a mechanical heart and lung apparatus to cardiac surgery. Minn Med. 1954;37(3):171-185; passim.
19Ascione R, Lloyd CT, Gomes WJ, Caputo M, Bryan AJ, Angelini GD. Beating versus arrested heart revascularization: evaluation of myocardial function in a prospective randomized study. Eur J Cardiothorac Surg. 1999;15(5):685-690.
20Ascione R, Lloyd CT, Underwood MJ, Lotto AA, Pitsis AA, Angelini GD. Inflammatory response after coronary revascularization with or without cardiopulmonary bypass. Ann Thorac Surg. 2000;69(4):1198-1204.
21Larmann J, Theilmeier G. Inflammatory response to cardiac surgery: cardiopulmonary bypass versus non-cardiopulmonary bypass surgery. Best Pract Res Clin Anaesthesiol. 2004;18(3):425-438.
22Vandenberghe W, Gevaert S, Kellum JA, Bagshaw SM, Peperstraete H, Herck I, et al. Acute kidney ınjury in cardiorenal syndrome type 1 patients: a systematic review and meta-analysis. Cardiorenal Med. 2016;6(2):116-128.
23Hoste EA, Bagshaw SM, Bellomo R, Cely CM, Colman R, Cruz DN, et al. Epidemiology of acute kidney injury in critically ill patients: the multinational AKI-EPI study. Intensive Care Med. 2015;41(8):1411-1423.
24Khwaja A. KDIGO clinical practice guidelines for acute kidney injury. Nephron Clin Pract. 2012;120(4):c179-c184.
25Uchino S, Kellum JA, Bellomo R, Doig GS, Morimatsu H, Morgera S, et al. Acute renal failure in critically ill patients: a multinational, multicenter study. JAMA. 2005;294(7):813-818.
26Waikar SS, Liu KD, Chertow GM. Diagnosis, epidemiology and outcomes of acute kidney injury. Clin J Am Soc Nephrol. 2008;3(3):844-861.
27Sakan S, Povšić Čevra Z, Tomulić Brusich K, Juranko V, Prajdić Predrijevac D, Novkovski M, et al. A single center retrospective study of cardiac surgery associated acute kidney injury incidence and outcomes. Acta Med Croatica. 2017;71(4):285-291.
28Siew ED, Matheny ME, Ikizler TA, Lewis JB, Miller RA, Waitman LR, et al. Commonly used surrogates for baseline renal function affect the classification and prognosis of acute kidney injury. Kidney Int. 2010;77(6):536-542.
29Birnie K, Verheyden V, Pagano D, Bhabra M, Tilling K, Sterne JA, et al. Predictive models for kidney disease: improving global outcomes (KDIGO) defined acute kidney injury in UK cardiac surgery. Crit Care. 2014;18(6):606.
30Kowara Y, Setiawan P, Airlangga PS, Abbas KA, Perdhana F, Husain TA, et al. Relation Between Multiplication of Venous Carbon Dioxide Partial Pressure (PvCO 2 ) and the ratio of gas flow to pump flow (Ve/Q) with hyperlactatemia during cardiopulmonary bypass. Ann Card Anaesth. 2024;27(4):337-343.
31Brooks GA. Lactate as a fulcrum of metabolism. Redox Biol. 2020;35:101454.
32Zhang S, Zheng D, Chu XQ, Jiang YP, Wang CG, Zhang QM, et al. ΔPCO2 and ΔPCO2/C(a-cv)O2 Are Not Predictive of Organ Dysfunction After Cardiopulmonary Bypass. Front Cardiovasc Med. 2021;8:759826.
33Gailiunas P Jr, Chawla R, Lazarus JM, Cohn L, Sanders J, Merrill JP. Acute renal failure following cardiac operations. J Thorac Cardiovasc Surg. 1980;79(2):241-243.
