Urinary output and fractional excretion of sodium and urea as indicators of transient versus intrinsic acute kidney injury during early sepsis

Abstract

IntroductionThe pathophysiology of acute kidney injury (AKI) in sepsis is ill defined. We investigated parameters associated with low glomerular filtration, and their predictive value to discriminate transient from intrinsic septic AKI.MethodsIn 107 sepsis patients, AKI was defined by the Risk, Injury, Failure, Loss of Kidney Function, End-stage renal disease (RIFLE) urinary output or serum creatinine criterion, or both. Transient AKI (TAKI) versus intrinsic AKI was defined as RIFLE R, I, or F on the first day evolving to no AKI or not, respectively, over the following 5 days. Fractional excretion of sodium (FENa), urea (FEUrea), and NGAL (FENGAL) at admission (d0t0), 4 (d0t4), and 24 hours (d1) was determined.ResultsIncluding versus not including the urinary-output criterion of RIFLE increased AKI from 43% to 64.5%. Median uNGAL levels and FENGAL were lower in no AKI versus transient AKI when AKI was defined based on creatinine (P = 0.002 and P = 0.04, respectively), but not when based on urinary output (P = 0.9 and P = 0.49, respectively). FENa < 1% and FEUrea <35% was present in 77.3% and 63.2% of patients. Urinary NGAL was higher (P < 0.001) in those with high versus low fractional sodium excretion, but this was only in patients with transient or intrinsic AKI (P < 0.001 in subgroups), and not in patients without AKI. The negative predictive value for either intrinsic AKI or not restoring diuresis in patients with FENa > 0.36% and FEUrea > 31.5% was 92% and 94.5% respectively.ConclusionsA low FENa and FEUrea is highly prevalent in the first hours of sepsis. In sepsis, oliguria is an earlier sign of impending AKI than increase in serum creatinine. A combination of a high FENa and a low FEUrea is associated with intrinsic AKI, whereas a combined high FENa and FEUrea is strongly predictive of transient AKI.

Disease indicators for sepsis and analysis of sepsis treatment in children using the continuous blood purification technique

“…Bacterial infections are one of the major causes of sepsis (Vanmassenhove et al, 2013). The interaction between the host and the microorganism activates the natural immunity pathway and triggers defensive mechanisms in the host, including body fluid composition and cells.…”

Oliguria and Biomarkers of Acute Kidney Injury: Star Struck Lovers or Strangers in the Night?

“…However, the measurement of the FENa is also subject to error particularly in the critically ill where loop diuretics, for example, are often used and are, unsurprisingly, associated with an FENa in excess of 1% regardless of volume state. Also values of <1% have been observed in many conditions associated with parenchymal renal disease as well as in sepsis [20] and the FENa may be >1% when pre-renal disease is present in sodium-wasting states such as in chronic kidney disease. As such, it is of little use in isolation and results should be viewed with caution.…”

“…Calculated in a similar fashion, the fractional excretion of urea (FEUrea) has been proposed as a superior test given the lack of a significant effect of diuretics that may have been administered, with an FEUrea <35% indicative of a pre-renal cause. However, interpretation remains difficult in the critically ill [21], especially in sepsis where a FEUrea <35% was found in 63% of patients and discrimination between transitory and intrinsic AKI was negligible (area under the curve (AUC) 0.36) [20]. However, all septic patients who were classified as AKI stage 3 by oliguria presented with an FEUrea <20% (table 2) [20].…”

Sepsis oluşturulan sıçanlarda farklı konsantrasyonlarda verilen albuminin böbrek antioksidan ve serbest oksijen radikalleri üzerine etkisi

“…Aynı zamanda infeksiyöz ajanlar lokal inflamatuar medyatörler salarak, renal mikrosirkülasyonu değiştirerek ve/veya endothelial yapıyı hasarlayarak böbrek fonksiyonlarını bozarlar [22].…”