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 CO 2 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.

Metabolic and Endocrine Challenges

“…Thyroid emergencies are rare, but life-threatening endocrine emergencies are associated with a poor outcome and high mortality. 149 Therefore, a prompt diagnosis and an early start of treatment are essential. The most common thyroid emergencies are myxedema coma and thyroid storm.…”

“…The most common thyroid emergencies are myxedema coma and thyroid storm. Myxedema coma is the most extreme expression of severe hypothyroidism with hormone deficiency, 149 while thyroid storm is associated with a decompensated thyrotoxicosis in hyperthyroidism. 150 Both develop from the longstanding thyroid dysfunction that has not been diagnosed, or is untreated or undertreated.…”

“…But contrary to the name, most patients are not comatose either; therefore, the diagnosis must be based on key features like medical history, deteriorating mental status, hypothermia, and potential triggering events like an infection, drugs, or trauma. 149,151 Other nonspecific symptoms include a myxedematous face with macroglossia and hyporeflexia of deep tendons (also known as Woltman sign). Since older women are more affected by hypothyroidism, typical myxedema coma patients tend to be elderly women over 60 years, and 90% of all cases occur in wintertime and at lower temperatures.…”

“…The symptoms of thyroid storm are more pronounced than hyperthyroidism, and can be accompanied by fever. 149 Manifestations range from hyperthermia, gastrointestinal, or hepatic disorders, and tremor, to congestive heart failure. The latter may also be the most common clinical manifestation and requires rapid treatment, because the resulting cardiogenic shock appears to be associated with fatal outcomes.…”

“…The latter may also be the most common clinical manifestation and requires rapid treatment, because the resulting cardiogenic shock appears to be associated with fatal outcomes. 149,153…”