Certified Nurses Operating Room (CNOR) Practice Exam

In an adult patient, what is the normal sodium (Na) value range?

1. 120-130

2. 130-140

3. 136-145

4. 140-150

The correct answer is: 136-145

The normal sodium (Na) value range for an adult patient is typically between 136 and 145 milliequivalents per liter (mEq/L). This range is critical for maintaining proper fluid balance, nerve function, and muscle contraction in the body. Sodium is a key electrolyte in the extracellular fluid, and its concentration is tightly regulated by various physiological mechanisms, including renal function and hormonal regulation. Levels below 136 mEq/L indicate hyponatremia, which can lead to symptoms like confusion, seizures, and muscle cramps, while levels above 145 mEq/L suggest hypernatremia, potentially resulting in dehydration and neurological disturbances. This established normal range allows healthcare professionals to assess a patient's electrolyte status effectively and to intervene appropriately in cases of imbalance.