Objectives: We sought to determine how early we can detect acute kidney injury inpatients at intensive care unit admission by combining the use of plasma creatinine and urinary γ-glutamyl transpeptidase.
Design: Prospective study including development (n = 100) and validation (n = 56) cohorts.
Settings: Intensive care unit of a university hospital.
Measurements and Main Results: To determine acute kidney injury, we subtracted measured creatinine clearance from theoretical creatinine clearance with a 25% reduction signifying acute kidney injury. Its incidence in 100 consecutive patients was 36%. An indexed urinary γ-glutamyl transpeptidase–to–urinary creatinine ratio was significantly increased in the patients with acute kidney injury and did not correlate with plasma creatinine (p = .3). Using a predefined threshold of indexed urinary γ-glutamyl transpeptidase–to–urinary creatinine ratio (>12.4 units/mmol) and plasma creatinine (>89 μmol/L), acute kidney injury detection was significantly improved, making it possible to detect 22 (22%) additional patients with acute kidney injury. This finding was confirmed in the validation group. The rates of false-positive results were 30% and 19% in the data development and internal validation cohorts, respectively.
Conclusions: The use of low-cost, widely available markers (creatinine and urinary γ-glutamyl transpeptidase) increases the detection of acute kidney injury. Further studies are needed to determine the impact on outcome with the use of these biomarkers.
From the Service d'anesthésie et de réanimation, Hôpital Nord, Assistance Publique—Hôpitaux de Marseille, Université de la Méditerranée, Marseille, France.
The authors have not disclosed any potential conflicts of interest.
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