Perioperative hemoglobin area under the curve is an independent predictor of renal failure after cardiac surgery. Results from a Spanish multicenter retrospective cohort study

• Published in: PloS one Vol. 12; no. 2; p. e0172021
• Main Authors: Duque-Sosa, Paula, Martínez-Urbistondo, Diego, Echarri, Gemma, Callejas, Raquel, Iribarren, María Josefa, Rábago, Gregorio, Monedero, Pablo
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 22.02.2017; Public Library of Science (PLoS)
• Subjects: Acute Kidney Injury - blood; Acute Kidney Injury - diagnosis; Acute Kidney Injury - etiology; Aged; Analysis; Anemia; Anesthesiology; Area Under Curve; Biology and Life Sciences; Bleeding; Blood; Blood transfusion; Cardiac Surgical Procedures - adverse effects; Cardiovascular disease; Chronic obstructive pulmonary disease; Cohort analysis; Complications and side effects; Coronary artery bypass; Creatinine; Critical care; Erythrocytes; Family medical history; Female; Health aspects; Heart; Heart diseases; Heart surgery; Hemoglobin; Hemoglobins - analysis; Humans; Intensive care; Kidney failure; Kidneys; Length of Stay; Male; Medicine and Health Sciences; Middle Aged; Mortality; Patients; Perioperative Period; Postoperative Complications - blood; Postoperative Complications - diagnosis; Postoperative Complications - etiology; Predictive Value of Tests; Prognosis; Regression analysis; Renal failure; Renal Insufficiency - blood; Renal Insufficiency - diagnosis; Renal Insufficiency - etiology; Retrospective Studies; Risk Factors; Spain; Surgery; Transfusion; Spain
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0172021

Perioperative anemia is an important risk factor for cardiac surgery-associated acute kidney injury (CSA-AKI). Nonetheless, the severity of the anemia and the time in the perioperative period in which the hemoglobin level should be considered as a risk factor is conflicting. The present study introduces the concept of perioperative hemoglobin area under the curve (pHb-AUC) as a surrogate marker of the evolution of perioperative hemoglobin concentration. Through a retrospective analysis of prospectively collected data, we assessed this new variable as a risk factor for the development of acute kidney injury after cardiac surgery in 966 adult patients who underwent cardiac surgery with cardiopulmonary bypass, at twenty-three academic hospitals in Spain. Exclusion criteria were patients on renal replacement therapy, who needed a reoperation because of bleeding and/or with missing perioperative hemoglobin or creatinine values. Using a multivariate regression analysis, we found that a pHb-AUC <19 g/dL was an independent risk factor for CSA-AKI even after adjustment for intraoperative red blood cell transfusion (OR 1.41, p <0.05). It was also associated with mortality (OR 2.48, p <0.01) and prolonged hospital length of stay (4.67 ± 0.99 days, p <0.001).