Effect of goal-directed therapy on post-operative neutrophil gelatinase-associated lipocalin profile in patients undergoing on-pump coronary artery surgery.

Abstract

Neutrophil gelatinase-associated lipocalin (NGAL) is an early biomarker of acute kidney injury (AKI). Goal-directed therapy (GDT) in on-pump coronary artery bypass grafting (CABG) has been associated with lower post-operative NGAL levels in recent studies. The present study aimed at comparing plasma (P) and urinary (U)-NGAL levels following the use of GDT versus conventional haemodynamic therapy (CT) in patients undergoing on-pump CABG. A prospective randomised controlled study conducted in a single university hospital. A total of 54 patients in the GDT group and 56 patients in CT group after exclusions. U-NGAL was significantly lower immediately post-surgery (T 1) in GDT group (25.11 ± 1.5 versus 27.80 ± 1.7μg/L; p < 0.001) and at 4h (T 2) (38.19 ± 23.6 versus 52.30 ± 28.3μg/L; p = 0.006) and at 24h post-operatively (T 3) (34.85 ± 14 versus 39.7 ± 11.1μg/L; p = 0.047). P-NGAL was comparable between groups at T 1 but lower in the GDT group at T 2 (92.81 ± 4.8 versus 94.77 ± 4.5μg/L; p = 0.03) and T 3 (67.44 ± 3.7 versus 75.96 ± 5.3μg/L; p < 0.001). U-NGAL levels correlated well with the peak post-operative creatinine as compared to P-NGAL. On-pump patients manifest neutrophil activation, accounting for comparable levels of P-NGAL in the two groups at T 1. GDT-based haemodynamic management resulted in lower U-NGAL levels at T 1, T 2 and T 3 and lower P-NGAL levels at T 2 and T 3. Haemodynamic optimisation with GDT prevents further renal insult initiated with the inflammatory activation with cardiopulmonary bypass (CPB), as evidenced by lower post-operative U-NGAL levels.