Acute kidney injury in critically ill obstetric patients: Incidence and role of neutrophil gelatinase-associated lipocalcin - A prospective observational cohort study.

BACKGROUND AND AIMS: Data focussing on acute kidney injury (AKI) in obstetric patients admitted to the intensive care unit (ICU) are scarce and even more so regarding the role of neutrophil gelatinase-associated lipocalcin (NGAL) in detecting AKI or predicting outcomes in these patients. Hence, we aim to evaluate the incidence of AKI in obstetric ICU patients and validate the role of urinary and serum NGAL in predicting the onset of AKI and mortality.

METHODS: This prospective observational cohort included 45 obstetric patients admitted in ICU, excluding those with prior renal dysfunction. Serum creatinine and urine output were monitored for the occurrence of AKI during the ICU stay. The outcome of the patient (survival or death) in the ICU and hospital was recorded, and serum and urinary NGAL were determined at the time of ICU admission.

RESULTS: AKI occurred in 32 [71.1%; 95% confidence interval (CI): 55.4%, 86.8%] patients during their ICU stay. Serum NGAL showed an area under receiver operating characteristic curve (AUROCC) of 0.630 (95% CI: 0.417, 0.842) ( P = 0.231) for AKI and 0.486 (95% CI: 0.295, 0.676) ( P = 0.883) for ICU mortality. Urinary NGAL showed AUROC = 0.472 (95% CI: 0.285, 0.660) ( P = 0.772) to predict AKI and 0.430 (95% CI: 0.268, 0.652) ( P = 0.684) for ICU mortality.

CONCLUSIONS: AKI is common amongst critically ill obstetric ICU patients. However, serum and urinary NGAL cannot be advocated to discriminate between patients with or without AKI or between survivors and non-survivors in critically ill obstetric patients.