Epidemiology of Acute Kidney Injury in the Intensive Care Unit:

• AKI is a significant issue in ICU patients with a high mortality rate and long-term morbidity.
• Incidence of AKI in the ICU is around 50%, with different stages and causes identified.

Biologic Characteristics of Current Tools in AKI:

• Serum creatinine and urine output are traditionally used for AKI diagnosis but have limitations.
• Creatinine levels are influenced by various factors and may not reflect true kidney function.

Biologic Characteristics of Novel AKI Biomarkers with Short Turn-Around Times:

• New biomarkers like cystatin C, NGAL, and cell-cycle arrest markers offer quicker results and improved sensitivity.
• Cystatin C, for instance, correlates better with GFR and can detect AKI more efficiently than creatinine.

Serum Cystatin C:

• Cystatin C, a 13-kDa protein, is a reliable marker of GFR with better diagnostic accuracy than creatinine.
• Serum cystatin C reacts faster to changes in kidney function, making it a valuable tool in critically ill patients.

Further Novel AKI Biomarkers:

• Novel biomarkers like IL-6, IL-18, KIM-1, and L-FABP play crucial roles in AKI detection.
• These biomarkers provide insights into kidney injury beyond what traditional tools offer.

Impact of Thyroid Function:

• Limited relevance in critically ill patients.
• Inflammation's effect on serum cystatin C levels.

Neutrophil Gelatinase–Associated Lipocalin (NGAL):

• Origin and expression in various human tissues.