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

The loss of antidiuretic hormone (ADH) and adrenocorticotropic hormone (ACTH) after brain death leads to significant metabolic changes. ADH plays a crucial role in regulating water balance in the body, while ACTH stimulates the adrenal cortex to produce cortisol, a hormone essential for maintaining glucose metabolism and managing stress.

When ADH is lost, there is an inability to concentrate urine, leading to increased fluid loss and potentially resulting in dehydration. This dehydration can cause a reduction in the volume of circulating blood, subsequently leading to inadequate oxygen delivery to tissues. The body compensates for this reduced oxygen availability by shifting its metabolism from aerobic, which requires oxygen, to anaerobic metabolism, which occurs in the absence of sufficient oxygen.

Anaerobic metabolism is less efficient for energy production and can lead to the accumulation of lactic acid, contributing to metabolic acidosis. This shift is a response to the energy demands of the cells when faced with decreased oxygen supplies. Therefore, the metabolic change of shifting from aerobic to anaerobic metabolism is a direct consequence of the loss of ADH and ACTH after brain death, making it the correct answer in this scenario.