Which of the following signs is indicative of intrarenal renal failure?

The indication of high urine sodium levels is a significant marker of intrarenal renal failure. In this context, when the kidneys themselves are damaged, such as in acute tubular necrosis or other forms of intrarenal pathology, the ability of the tubules to reabsorb sodium is compromised. As a result, the urine sodium concentration tends to be elevated. High urine sodium becomes a distinguishing feature of renal failure originating from intrinsic kidney conditions.

In contrast, other signs, while relevant to kidney function or overall health, do not specifically point to intrarenal renal failure in the same manner. Low blood pressure may be observed in various types of renal failure or systemic conditions but does not specifically indicate intrarenal issues. High potassium levels can occur with any type of renal failure, as the kidneys struggle to excrete potassium, but they are not exclusive to intrarenal failure and can be seen in pre-renal or post-renal failure as well. Decreased heart rate is not a typical sign associated with renal failure and could be influenced by numerous factors unrelated to kidney function.

Understanding urine sodium levels in the context of renal failure is critical for differentiating types of kidney injuries and tailoring appropriate interventions.