Oncology Certified Nurse (OCN) Nursing Practice Test

What is the normal range for serum potassium levels?

1. 2.5-3.5 meq/L

2. 3.5-5.0 meq/L

3. 5.0-6.0 meq/L

4. 8.5-10.5 meq/L

The correct answer is: 3.5-5.0 meq/L

The normal range for serum potassium levels is 3.5-5.0 meq/L. This range is critical because potassium is an essential electrolyte that plays a key role in numerous physiological processes, including muscle contraction, nerve function, and maintaining normal heart rhythms. Levels outside this range can lead to serious complications; low levels (hypokalemia) may cause muscle weakness, irregular heart rhythms, and other muscular issues, while high levels (hyperkalemia) can also disrupt cardiac function and lead to potentially life-threatening arrhythmias. Accurate understanding of these normal values is crucial for healthcare providers in monitoring patients, particularly those undergoing treatment for cancer, as their potassium levels can be affected by various factors, including medications and changes in diet.