Prognostic Role of Ngal in Critically Ill Patients

Acute kidney injury (AKI) is a frequently encountered outcome in critically ill patients, accounting for increased mortality. Neutrophil gelatinase associated lipocalin (NGAL) has been of paramount importance as a novel biomarker of AKI. This study is an attempt to assess the use of NGAL in critically ill patients so that timely interventions can be done to reduce morbidity and mortality in such patients.

A prospective observational study was conducted at SRN Hospital, Prayagraj from August 1st 2020 to March 15th 2021, which included only critically ill patients with SOFA score>1 and requiring ICU admission. Patients of known renal diseases were excluded from the study. Blood as well as urinary samples for NGAL and other laboratory parameters were collected within 8 hours of admission. Patients who developed renal dysfunction were noted as our cases and the others were noted as controls.

The study was done on 125 patients, out of which 67 developed AKI while 58 did not develop AKI. Higher mortality was seen in patients with higher stage of AKI (P- 0.011). The cutoff of serum and urinary NGAL for predicting AKI were >42.3 ng/mL, >40.5 ng/mL respectively (P value <0.001). Hazard Ratio for all cause mortality of raised serum and urinary NGAL was 2.0062 (p value- 0.0001, 95% CI-1.0031 to 1.0092) and 2.0046 (p value-0.0035, 95% CI-1.0015 to 1.0078) respectively. Serum and urinary neutrophil gelatinase associated lipocalin at values >91 and >131 respectively were found to predict requirement of hemodialysis (p value<0.001).

A single measurement of NGAL at the time of admission had good predictive ability for AKI. Higher values of NGAL were associated with staging of AKI and thus, correlated with need of hemodialysis. Furthermore, mortality was found to be associated with development of AKI and raised NGAL. Thus, NGAL maybe used to assess the prognosis of ICU patients so that patients at high risk may be managed aggressively, thus reducing mortality.