Certified Clinical Transplant Nurse (CCTN) Practice Exam 2026 - Free CCTN Practice Questions and Study Guide

In cases of Diabetes Insipidus (DI), the most likely electrolyte to increase is sodium. This condition is characterized by a deficiency of the hormone vasopressin (antidiuretic hormone), which leads to the inability of the kidneys to concentrate urine. As a result, an excessive loss of water occurs, leading to dehydration and a subsequent increase in serum sodium levels, a situation known as hypernatremia.

The body attempts to compensate for the loss of water by promoting the retention of sodium. However, due to the significant volume of water loss, the ratio of sodium to water in the bloodstream becomes unbalanced, causing sodium levels to rise. This remarkable increase is especially evident in chronic cases where water intake does not adequately replace the losses.

Understanding the relationship between water loss and sodium concentration is crucial for healthcare providers managing patients with DI. Monitoring sodium levels is essential to prevent and address complications associated with hypernatremia.