Which test is primarily used to assess kidney function in patients with ESKD?

The test that is primarily used to assess kidney function in patients with end-stage kidney disease (ESKD) is serum creatinine. Serum creatinine is a waste product that results from muscle metabolism and is produced at a relatively constant rate by the body. The kidneys play a crucial role in filtering creatinine from the blood and excreting it in urine. When kidney function diminishes, as it does in ESKD, serum creatinine levels rise.

This makes serum creatinine a reliable indicator of glomerular filtration rate (GFR) and overall kidney function. Monitoring serum creatinine levels allows healthcare providers to evaluate the extent of kidney impairment and adjust treatment plans as necessary. In the context of ESKD, elevated serum creatinine levels reflect a significant reduction in the kidneys' ability to filter waste.

While the other tests mentioned, like blood urea nitrogen (BUN), can also provide valuable information regarding kidney function, they can be influenced by factors unrelated to kidney health, such as hydration status or protein intake. Electrolyte panels assess the levels of various electrolytes that the kidneys regulate but do not directly measure kidney function. Uric acid levels are more helpful in diagnosing gout and assessing purine metabolism rather than kidney function specifically.