Which laboratory finding would most likely indicate dehydrated state?

A high blood urea nitrogen (BUN) level is indicative of a dehydrated state primarily because it reflects the concentration of urea in the blood, which is influenced by the body's hydration status. When a person is dehydrated, there is a reduction in blood volume and an increase in the concentration of urea due to decreased renal perfusion. This leads to increased reabsorption of urea in the kidneys, resulting in elevated BUN levels.

In hydrated individuals, BUN levels are typically lower, as adequate fluid levels facilitate the excretion of urea. BUN is a product of protein metabolism, and under normal hydration conditions, the kidneys efficiently filter and eliminate it from the bloodstream.

While creatinine is another important marker of kidney function, a normal creatinine level does not provide a definitive indication of dehydration. Potassium levels can vary based on numerous factors, and a high potassium level does not specifically correlate with hydration status.