Which lab value is critical to review before administering potassium supplements?

Reviewing serum potassium levels is critical before administering potassium supplements because the supplementation is specifically used to correct low potassium levels, also known as hypokalemia. Administering potassium when levels are already normal or high can lead to hyperkalemia, a potentially life-threatening condition characterized by elevated potassium in the blood. It can cause serious cardiac complications, including arrhythmias. Therefore, ensuring that serum potassium levels are assessed allows the healthcare provider to determine the necessity and appropriateness of potassium supplementation, thus safeguarding patient safety. Other lab values, while important in comprehensive patient assessment, do not directly indicate the need for potassium supplementation in the same way.