The term thyrotoxic crisis refers to a sudden and life-threatening metabolic derailment. It usually develops at the base of an existing hyperthyroidism.
What is a thyrotoxic crisis?
Thyrotoxic crisis is a life-threatening derailment of hyperthyroidism. The clinical picture develops within a few hours or days. In thyrotoxic crisis, all the symptoms of hyperthyroidism appear in a very severe form. The crisis is often triggered by increased iodine intake or by X-ray contrast medium containing iodine. In this case, the thyrotoxic crisis occurs approximately one to four weeks after admission. Discontinuation of thyrostatic drugs may also cause thyrotoxic crisis. The crisis requires immediate intensive medical care. If left untreated, it can lead to death.
Causes
A thyrotoxic crisis can develop only from hyperthyroidism. In hyperthyroidism, the thyroid gland produces too much thyroid hormone. The two main thyroid hormones are triiodothyronine (T3) and thyroxine (T4). The basic component of thyroid hormones is the trace element iodine. The main cause of hyperthyroidism is the autoimmune disease Graves’ disease. In this disease, the body’s own antibodies bind to the TSH receptors of the thyroid gland and thus mimic the action of thyroid-stimulating hormone (TSH) from the pituitary gland. This results in a constant production of T3 and T4, leading to hyperthyroidism. Hyperthyroidism, however, can also develop as a result of thyroid autonomy. In thyroid autonomy, individual areas of the thyroid gland function independently of hormonal regulatory mechanisms. Furthermore, hyperthyroidism can be caused by hormone-producing tumors of the thyroid gland and by thyroiditis. Thyrotoxic crisis usually develops after high iodine intake. This makes more iodine available to the body for the production of thyroid hormones. Since the body’s hormonal regulatory mechanisms are impaired in hyperthyroidism, production is also not curbed. Thyrotoxic crisis is often induced iatrogenically, by the physician, by administration of iodine-containing drugs. Contrast media containing X-rays are also common triggers. It also becomes dangerous when patients with hyperthyroidism independently discontinue their medications. Thyrostatic drugs prevent the thyroid gland from producing too many hormones. If the drugs are stopped suddenly, it can result in a thyrotoxic crisis. Surgery can also cause a thyrotoxic crisis. In particular, after removal of thyroid tissue, thyroid hormone production can increase reactively.
Symptoms, complaints, and signs
Typical symptoms of hyperthyroidism include insomnia, irritability, and nervousness. In many patients, a fine-beat tremor, a mild shaking, is seen as a sign of restlessness. Thyroid hormones stimulate the entire metabolism. Blood pressure is high. The difference between the systolic and diastolic blood pressure values (blood pressure amplitude) is increased. The heart activity is changed. The heart beats faster, sometimes the affected person suffers from heart strokes (extrasystoles). Atrial fibrillation can also be the result of hyperthyroidism. Patients feel hungry due to the increased energy metabolism, but still lose weight. Hyperglycemia may occur due to the mobilization of glycogen reserves and fat reserves. Patients sweat rapidly, are intolerant of heat, and have moist warm skin. They need to visit a toilet more frequently and have thin stools. The musculature is weak. In thyrotoxic crisis, all these symptoms intensify massively and within a very short time. In stage I thyrotoxic crisis, the heart rate is increased to more than 150 beats per minute. Patients vomit and have a high fever. Desiccosis may develop due to increased fluid excretion. In stage II of the crisis, patients are increasingly disoriented and clouded in consciousness. They are dazed or drowsy. In stage III, the ill fall into a coma. The increased heart rate, cardiac arrhythmias and dehydration are particularly threatening. If left untreated, coma threatens irreversible late effects.Overall, the prognosis of thyrotoxic crisis is rather poor. It is frequently fatal.
Diagnosis and course of the disease
A tentative diagnosis can be made quite quickly on the basis of characteristic symptoms. The decisive clue is provided by an already known hyperthyroidism. The elevated thyroid levels can be detected in the blood in thyrotoxic crisis. The TSH value is strongly decreased. TSH stimulates the thyroid gland to produce thyroid hormones. However, because there are far too many thyroid hormones in the blood due to thyrotoxic crisis, the pituitary gland produces less TSH. Levels of the thyroid hormones T3 and T4 are still elevated.
Complications
If a thyrotoxic crisis develops, it affects the entire metabolism. Blood pressure is elevated, nervousness, irritability, and sleep disturbances occur, and tremors set in. In addition, cardiac activity is altered and sufferers experience heart palpitations and atrial fibrillation – both of which can lead to serious complications, including heart failure. Accompanying the general symptoms is weight loss, usually associated with dehydration and deficiency symptoms. Mobilization of glycogen and fat reserves can lead to hyperglycemia. In addition, the patients are physically weak and suffer from muscle weakness. In thyrotoxic crisis, all these symptoms increase within a very short time. High fever, dehydration and impaired consciousness develop relatively quickly. Subsequently, patients fall into a coma. Loss of consciousness, if not treated or treated too late, usually has irreversible late effects or even leads to death. The treatment of a thyrotoxic crisis can be affected by the typical side effects and interactions of prescribed drugs. Thus, surgical intervention is always risky because the patient is usually already considerably weakened.
When should you go to the doctor?
A high blood pressure, an inner restlessness, nervousness and irritability are complaints that should basically be clarified by a doctor. If they persist unchanged for several weeks or months, they must be examined. If the irregularities increase, a visit to the doctor is necessary immediately. If there are disturbances of the heart rhythm, a decrease in muscle strength or a loss of general resilience, consultation with a doctor is recommended. Fever, vomiting, malaise, as well as a feeling of illness should be presented to a physician. Because thyrotoxic crisis is a health emergency, acute changes in well-being often occur within a short time. In the event of sudden inconsistencies, emergency medical services should be alerted. Characteristic of the disorder is that even before the onset, affected individuals lose weight, although they consume an unusually large number of calories daily. Unwanted weight loss is an alarm signal of the body. In case of disturbances of consciousness, disorientation as well as disturbances of memory activity, an emergency service must be called. Present persons are in the obligation to apply measures of first aid. Without timely and professional medical care, the affected person risks a comatose state as well as irreparable damage to organs. Therefore, there is an acute need for action if there is a significant deterioration of health.
Treatment and therapy
Thyrotoxic crisis is always treated in the intensive care unit. Cardiovascular system functions are closely monitored. In addition, fluid intake and excretion are monitored. In this way, fluid balancing can take place and exsiccosis can be counteracted. Patients receive three to four liters of fluid per day. Medications are also used to restrict the production and secretion of thyroid hormones. These include thyrostatic drugs such as thiamazole and glucocorticoids such as prednisolone. Beta-blockers are used to regulate increased heart rate. If the fever is severe, ice packs can be used to cool it. Paracetamol or ibuprofen can also reduce fever. If the patient is suffering from severe agitation, sedation can be given. If the thyrotoxic crisis was caused by iodine contamination and none of the measures described help, the thyroid gland is removed almost completely in a surgical procedure. Plasmapheresis may also be performed to remove the iodine from the blood.
Prevention
Consistent treatment of hyperthyroidism can usually prevent thyrotoxic crisis. Patients with known hyperthyroidism should not take medications with high iodine content. Thyroid function should also be monitored in special situations, such as infections or surgery.
Follow-up
Unlike hyperthyroidism, thyrotoxic crisis poses an acute threat to life. It does not develop chronically but takes a fulminant course. However, the crisis is usually preceded by hyperthyroidism. Timely medical intervention is necessary to prevent a life-threatening outcome of the disease. In such cases, treatment and follow-up care run in parallel. The goal of therapy is to normalize thyroid levels and avert the life-threatening condition. The danger to life is not the same in every thyrotoxic crisis. In the early stage, a lethal outcome is about 10 percent likely; in the advanced course, the probability is already 30 percent. The last option in severe cases is surgical reduction of the thyroid gland. However, immediate treatment is always necessary. The patient is hospitalized for this purpose. When appropriate medicine is administered, the internist in charge verifies the cure. In addition, the affected person receives medication against further complaints such as nausea or dizziness. If the crisis has been successfully contained, follow-up care is gradually discontinued and ends with discharge. If thyroid surgery is performed, the usual follow-up methods are scheduled. Occasional follow-up visits are performed by the primary care physician. The patient must attend the appointments so that possible new changes in the thyroid gland are detected early.
What you can do yourself
Thyrotoxic crisis is a medical emergency because the patient’s health can deteriorate rapidly and possibly lead to death. It is therefore of utmost importance that patients do not attempt to relieve their condition on their own through self-help measures. This is not possible and increases the risk of death as a result of thyrotoxic crisis. If individuals notice symptoms of Thyrotoxic Crisis in themselves or experience other severe symptoms, contact an emergency physician immediately. Once under medical care, patients with a Thyrotoxic Crisis will follow all instructions given by staff, whether they are physicians or nurses. Individuals with a thyrotoxic crisis are usually first admitted to a hospital and treated as an inpatient until their health improves. For this purpose, patients receive appropriate medication in prescribed doses. Regular and proper intake of these drugs is essential, otherwise the symptoms may recur. Digestive problems are also treated with medication, and patients also receive adequate meals in the hospital. Since many sufferers have nervousness, sedatives are sometimes used.
