Thyroid emergencies.

Abstract

Myxedema coma and thyroid storm are among the most common endocrine emergencies presenting to general hospitals. Myxedema coma represents the most extreme, life threatening expression of severe hypothyroidism with subjects presenting with deteriorating mental status, hypothermia, and multiple organ system abnormalities. It typically appears in patients with pre-existing hypothyroidism via a common pathway of respiratory decompensation with CO2 narcosis leading to coma. Without early and appropriate therapy, there is often a fatal outcome. It is a clinical diagnosis based on history and physical findings at presentation and not on any objective thyroid laboratory tests. Clinically based scoring systems have been proposed to aid in the diagnosis. While a relatively rare syndrome, the typical patient is an elderly woman (thyroid hypofunction being much more common in women) who may or may not have a history of previously diagnosed or treated thyroid dysfunction. Thyrotoxic storm or thyroid crisis also is a rare condition and it too reflects a clinical diagnosis. Diagnosis is based upon the appearance of severe hyperthyroidism accompanied by elements of systemic decompensation. Based upon the prospect of high mortality without aggressive treatment, therapy must be initiated as early as possible in a critical care setting. There are no clues to diagnosis based upon laboratory tests alone, but several scoring systems have been developed to aid in diagnosis. The usual clinical signs and symptoms of hyperthyroidism will be present along with more exaggerated clinical manifestations affecting the cardiovascular, gastrointestinal, and central nervous systems. A multi-pronged treatment approach has been recommended and has been associated with improved outcomes.