[The euthyroid sick syndrome in severe acute illness]

Area of Science:

• Endocrinology
• Critical Care Medicine
• Internal Medicine

Background:

• Severe acute illness frequently triggers thyroid dysfunction, termed euthyroid sick syndrome (ESS).
• ESS encompasses various clinical presentations and hormonal alterations.
• Understanding ESS is crucial for managing critically ill patients.

Purpose of the Study:

• To characterize euthyroid sick syndrome (ESS) and its clinical variants in patients with severe acute illness.
• To investigate the prevalence of ESS and its impact on mortality.
• To identify thyroid indicators with prognostic value in critically ill patients.

Main Methods:

• Prospective cohort study involving 108 intensive care unit (ICU) patients.
• Analysis of hormone results and patient outcomes.
• Assessment of ESS prevalence, mortality correlation, and prognostic thyroid indicators.

Main Results:

• The prevalence of ESS was observed to be 68.5% for Type I, 15.7% for Type II, and 1.9% for Type III.
• Thyroid alterations typically emerged by the third day of hospitalization.
• Patients with ESS Type II exhibited a significantly higher mortality rate.

Conclusions:

• Severe acute illness induces euthyroid sick syndrome (ESS).
• ESS Type I is most common, but ESS Type II is associated with increased mortality.
• Reverse triiodothyronine (rT3) levels exceeding 0.61 ng/mL were identified as the sole thyroid indicator with prognostic significance.