NGAL expression during cardiopulmonary bypass does not predict severity of postoperative acute kidney injury

Martin G Friedrich; Ioannis Bougioukas; Johanna Kolle; Christian Bireta; Fawad A Jebran; Marius Placzek; Theodor Tirilomis

doi:10.1186/s12882-017-0479-8

NGAL expression during cardiopulmonary bypass does not predict severity of postoperative acute kidney injury

BMC Nephrol. 2017 Feb 21;18(1):73. doi: 10.1186/s12882-017-0479-8.

Authors

Martin G Friedrich¹, Ioannis Bougioukas², Johanna Kolle², Christian Bireta², Fawad A Jebran², Marius Placzek³, Theodor Tirilomis²

Affiliations

¹ Department of Thoracic and Cardiovascular Surgery, University Medical Center Göttingen, Robert-Koch-Str. 40, 37075, Göttingen, Germany. martin.friedrich@med.uni-goettingen.de.
² Department of Thoracic and Cardiovascular Surgery, University Medical Center Göttingen, Robert-Koch-Str. 40, 37075, Göttingen, Germany.
³ Department of Medical Statistics, University Medical Center Göttingen, Göttingen, Germany.

Abstract

Background: Renal injury is a serious complication after cardiac surgery and therefore, early detection and much more prediction of postoperative kidney injury is desirable. Neutrophil gelatinase-associated lipocalin (NGAL) is a predictive biomarker of acute kidney injury and may increase after cardiopulmonary bypass (CPB). However, time correlation of NGAL expression and severity of renal injury is still unclear. The aim of our study was to investigate CPB-related urine NGAL (uNGAL) secretion in correlation to postoperative renal function.

Methods: Data of NGAL expression along with clinical data of 81 patients (52 male and 29 female) were included in this study. Mean age of the patients was 66.8 ± 12.8 years. Urine NGAL was measured at seven time points (T₀: baseline; T₁: start CPB, T₂: 40 min on CPB; T₃: 80 min on CPB; T₄: 120 min on CPB; T_p1: 15 min after CPB; T_p2: 4 h after admission to the intensive care unit) and renal function in the postoperative period was classified daily according to Acute Kidney Injury Network (Ronco et al, Int J Artif Organs 30(5): 373-6) criteria (AKIN).

Results: Expression of uNGAL increased at T₄ (120 min on CPB) and post-CPB (T_p1 and T_p2; p < 0.01 vs. baseline) but there was no correlation between uNGAL level and duration of CPB nor between uNGAL expression and occurrence of postoperative kidney injury. The renal function over 10 days after surgery remained normal in 50 patients (AKIN level 0), 18 patients (22%) developed mild and insignificant renal injury (AKIN level 1), eight patients (10%) developed moderate renal failure (AKIN level 2), and five patients (6%) severe kidney failure (AKIN level 3). Twenty-four out of 31 patients developed renal failure within the first 48 h after surgery. However, there was no correlation between uNGAL expression and severity of acute renal failure.

Conclusion: Although uNGAL expression increased after CPB, the peak values neither predict acute postoperative kidney injury, nor severity of the injury.

Keywords: Acute renal failure; Cardiac surgery; Cardiopulmonary bypass; Kidney injury; NGAL.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Acute Kidney Injury / epidemiology*
Acute Kidney Injury / physiopathology
Acute Kidney Injury / urine
Aged
Aged, 80 and over
Cardiac Surgical Procedures*
Cardiopulmonary Bypass*
Female
Humans
Lipocalin-2 / urine*
Male
Middle Aged
Postoperative Complications / epidemiology*
Postoperative Complications / physiopathology
Postoperative Complications / urine
Prognosis
Severity of Illness Index

Substances

LCN2 protein, human
Lipocalin-2