Which measurement is critical for accurately interpreting Cardiac Index?

Cardiac Index is a key parameter that provides an assessment of cardiac output relative to the body size, allowing for a more precise evaluation of the heart's performance. The measurement of Cardiac Index is critically dependent on Body Surface Area (BSA), as it allows clinicians to normalize cardiac output to the individual's size.

By using BSA, healthcare professionals can compare cardiac function across patients of different sizes and weights, ensuring that the assessment of cardiac health reflects the true workload and efficiency of the heart. This normalization is essential because cardiac output alone does not provide a complete picture when comparing individuals with significantly different body sizes.

The other options, while important in different clinical contexts, do not directly influence the interpretation of Cardiac Index in a meaningful way. Body temperature, blood glucose levels, and serum creatinine levels provide important information about metabolic status, renal function, and systemic health but do not affect the calculation or interpretation of Cardiac Index as directly as Body Surface Area does.