What is the normal cardiac index (CI) range?

The normal cardiac index (CI) range is indeed between 2.5 and 4.0 liters per minute per square meter (L/min/m²). Cardiac index is a critical measurement that reflects the efficiency of the heart in pumping blood relative to the body surface area, which enables clinicians to assess cardiac output in relation to the patient's size.

A CI lower than the normal range may indicate inadequate cardiac output, such as in cases of heart failure, while a CI higher than normal may suggest conditions such as septic shock or hyperdynamic circulation. Understanding the normal range is essential for evaluating a patient’s hemodynamic status and guiding treatment decisions in acute care settings.

While the other options present values outside the acceptable range for cardiac index, they do not align with the established clinical understanding of what constitutes a normal physiological measurement, which is why they are not the correct choice.