Which laboratory result is indicative of renal dysfunction in tumor lysis syndrome?

Elevated creatinine is a laboratory result that indicates renal dysfunction, particularly within the context of tumor lysis syndrome. Tumor lysis syndrome occurs when a large number of cancer cells are destroyed rapidly, leading to the release of their intracellular contents into the bloodstream. This can overwhelm the kidneys, which must process various metabolites, including those resulting from cell breakdown.

When the kidneys are unable to adequately filter blood due to the high levels of uric acid, potassium, and phosphate that can be released during tumor lysis, creatinine levels rise. Creatinine is a waste product generated from normal muscle metabolism and is usually removed from the bloodstream by healthy kidneys. Therefore, an elevation of creatinine serves as a marker for impaired renal function, suggesting that the kidneys are not performing their filtering role effectively in this syndrome.

In contrast, elevated glucose, low potassium, or normal calcium do not directly provide insights into renal function or its impairment. Glucose levels can fluctuate for various reasons unrelated to renal function, while low potassium may not occur in tumor lysis syndrome, as hyperkalemia (high potassium) is more typical. Normal calcium levels do not indicate renal dysfunction either. Thus, elevated creatinine is the most relevant and direct indicator of renal impairment in the context