Renal dysfunction in adults following cardiopulmonary bypass is linked to declines in S-nitroso hemoglobin: a case series.

Background

Impaired kidney function is frequently observed in patients following cardiopulmonary bypass (CPB). Our group has previously linked blood transfusion to acute declines in S-nitroso haemoglobin (SNO-Hb; the main regulator of tissue oxygen delivery), reductions in intraoperative renal blood flow, and postoperative kidney dysfunction. While not all CPB patients receive blood, kidney injury is still common. We hypothesized that the CPB procedure itself may negatively impact SNO-Hb levels leading to renal dysfunction.

Materials and methods

After obtaining written informed consent, blood samples were procured immediately before and after CPB, and on postoperative day (POD) 1. SNO-Hb levels, renal function (estimated glomerular filtration rate; eGFR), and plasma erythropoietin (EPO) concentrations were quantified. Additional outcome data were extracted from the patients' medical records.

Results

Twenty-seven patients were enroled, three withdrew consent, and one was excluded after developing bacteremia. SNO-Hb levels declined after surgery and were directly correlated with declines in eGFR (R=0.48). Conversely, plasma EPO concentrations were elevated and inversely correlated with SNO-Hb (R=-0.53) and eGFR (R=-0.55). Finally, ICU stay negatively correlated with SNO-Hb concentration (R=-0.32).

Conclusion

SNO-Hb levels are reduced following CPB in the absence of allogenic blood transfusion and are predictive of decreased renal function and prolonged ICU stay. Thus, therapies directed at maintaining or increasing SNO-Hb levels may improve outcomes in adult patients undergoing cardiac surgery.

Informations de copyright

Copyright © 2024 The Author(s). Published by Wolters Kluwer Health, Inc.

Déclaration de conflit d'intérêts

J.S.S. and J.D.R. hold patents related to renitrosylation, some of which may be licensed for commercial development. In addition, J.S.S. has an equity interest in SNO Bio, a company developing nitrosylation-related therapeutics, and is a consultant to NNOXX, a company developing devices to measure SNO-Hb. Their institutions are aware of these potential conflicts and appropriate management plans are in place. None of the other authors have relevant conflicts to disclose.Sponsorships or competing interests that may be relevant to content are disclosed at the end of this article.