Thyroid hormones and multiple organ dysfunction syndrome

Abstract

Marked changes in thyroid hormone levels occur in critical illness and multiple organ dysfunction syndrome (MODS), with a decrease in the active hormone T3 and an increase in the inactive metabolite rT3. The magnitude of these changes is related to the severity of the disease. Studies addressing the thyrotropic axis in critical illness do not make a clear distinction between patients with and without MODS. However, a distinction can be made between the acute and the more chronic phase of critical illness, and it can be assumed that patients who require intensive care for several days will have some degree of MODS. This review therefore focuses on the thyroid axis in patients receiving intensive care for several days. The mechanisms behind the observed changes, the potential positive and/or negative effects of them and their possible therapeutic consequences will be discussed.