Perioperative hemoglobin area under the curve is an independent predictor of renal failure after cardiac surgery. Results from a Spanish multicenter retrospective cohort study
Duque-Sosa P (1), Martínez-Urbistondo D (2), Echarri G (1), Callejas R (1), Iribarren MJ (1), Rábago G (3), Monedero P (1); Spanish group of renal dysfunction in cardiac surgery (GEDRCC-2).
(1) Department of Anesthesia and Critical Care, Clínica Universidad de Navarra, Pamplona, Navarra, Spain.
(2) Department of Internal Medicine, Division of Intermediate Care and Hospitalists Unit, Clínica Universidad de Navarra, Pamplona, Navarra Spain.
(3) Department of Cardiovascular Surgery, Clínica Universidad de Navarra, Pamplona, Navarra, Spain.
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).
CITATION PLoS One. 2017 Feb 22;12(2):e0172021. doi: 10.1371/journal.pone.0172021