Thyrotoxicosis in the critically ill.

The thyrotoxic patient offers a considerable challenge to the critical care physician because the "obvious" diagnosis often will be a cardiac (or other nonthyroidal) problem, but the "correct" diagnosis will be an endocrinologic one. The importance of considering the diagnosis of thyrotoxicosis in any patient with tachyarrhythmias, new-onset congestive heart failure, weight loss, or change in mental status cannot be overstated. Treatment for presumed thyroid disease sometimes will have to be initiated prior to the availability of the results of diagnostic tests. Timely and appropriate treatment of the thyroid problem is vital for a successful outcome in treating patients with thyrotoxicosis.