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Preoperative evaluation of patients with thyroid land disease, in any kind of surgery, should include the possibility of difficult intubation caused by thyromegaly, the hormonal status (its disbalance), as well as the screening, and therapy of consequences of thyroid imbalance on specific organ systems, especially cardiovascular. It is necessary to select the adequate anesthetics and other pharmacological agents, according to current hormonal status. It is also necessary to select the adequate medications and other therapeutic measures for prevention and treatment of possible complications in perioperative period, some of which are life-threatening (thyroid storm and mixedema coma).

Whereas Sir Victor Horsley is well known for his many contributions to neurosurgery, this is not the case for his treatments for both myxedema and cretinism. Horsley's research on thyroid physiology was concentrated in the years 1884-1890, while he was director of the Brown Institute for Animals. Based upon experimentation with dogs and monkeys as well as some human patients, Horsley demonstrated conclusively that removal of the thyroid gland produced tremors, rigidity, and paralysis, which he attributed to changes in lower motor centers. Furthermore, the development of imbecility suggested that thyroid excision produced deficits in higher cortical functioning. Horsley showed that it was possible to alleviate temporarily some of the psychological and physiological symptoms of both myxedema and cretinism using transplanted thyroid tissue. Several of Horsley's students, most notably George Murray, continued and extended his work by examining other ways in which myxedema and cretinism could be treated (e.g., by injecting an extract of thyroid tissue).

Purpose: To review the diagnosis and management of thyroid diseases, both metabolic (thyroid storm and myxedema coma) and anatomic (substernal goiter, lymphoma, anaplastic carcinoma) that may require intensive care therapy., Data Sources: English-language articles were identified through a search of the MEDLINE and Index Medicus databases. Bibliographies of retrieved articles were examined for relevant articles., Study Selection: Approximately 250 articles were reviewed. Those articles deemed most representative were utilized. Case reports were included to highlight rare, but potentially lethal complications., Data Extraction: All data were analyzed by one observer. Limitations of the data are discussed., Data Synthesis: Guidelines for determining the etiology of thyrotoxic crisis are outlined. Criteria for distinguishing critically ill hypothyroid patients from those patients with the euthyroid sick syndrome are given. Therapy for both disorders must be aggressive and multifaceted, and detailed management is indicated. Substernal goiter is almost always benign, but may cause various acute complications, including dyspnea, respiratory failure, superior vena caval syndrome, esophageal varices (downhill), and others. Surgery almost always corrects the problem. Lymphomas present with rapid thyroid enlargement. Recent studies suggest that surgery may assume more of a supportive role, used principally to obtain adequate tissue for histologic classification., Conclusions: Thyroid disorders can produce emergencies requiring the attention of multiple medical and surgical specialists. While management is often successful, future studies should address the following three areas: a) optimization of thyroid hormone dose for treatment of myxedema coma; b) clarification of the role of radiotherapy and/or chemotherapy for thyroid lymphoma; and c) more effective therapy for anaplastic carcinoma.

Thyroid storm is a rapid decompensation of severe hyperthyroidism which can best be described by the three criteria of hyperthermia, tachycardia and altered mental state with severe agitation. There has to be a precipitating factor such as infection, iodine contamination, surgery or even I-131 treatment. Severe hyperthyroidism not fulfilling the criteria of thyroid storm can also be an indication for emergency treatment, particularly in the elderly with heart disease. Suppressed serum TSH and elevated free T4 levels are essential to confirm the diagnosis. When rapidly available, radioiodine uptake of the thyroid can be useful. Therapy aims at rapidly reducing the active circulating hormone pool, hypermetabolic state, tachycardia, and finally hormone synthesis. Thyroid secretion can be blocked by ioipanoic acid or ipodate while hypermetabolic state can be reduced with beta-blockers or calcium channel-blockers. Treatment of hyperthyroidism in patients with iodine contamination is a real therapeutic challenge. Myxoedema coma, a complication of severe hypothyroidism, is defined by hypothermia (rectal temperature less than 36 degrees C), bradycardia, slow mentation, precipitating factor such as infection or drug overdose, and increased serum creatine phosphokinase levels. Diagnosis of severe hypothyroidism should be confirmed by serum measurements of TSH and free T4. Treatment consists of general supporting measures including rewarming, correction of serum electrolyte disturbances, and adequate alimentation. Thyroid hormone treatment should initially be aggressive using either 300-400 micrograms of T4 or 20-40 micrograms of T3 intravenously. Cortisone therapy may be added. Patients should be under close monitoring as arrhythmias and myocardial infarction are frequent complications of myxoedema coma and/or its treatment with thyroid hormones.