What is a thyrotoxic crisis?
The thyrotoxic crisis is a life-threatening derailment of hyperthyroidism (hyperthyroidism). The clinical picture develops within a few hours or days. In thyrotoxic crisis, all symptoms of hyperthyroidism show a very strong expression.
Often the crisis is triggered by increased iodine intake or by iodine-containing X-ray contrast agent. The thyrotoxic crisis occurs approximately one to four weeks after admission. The discontinuation of antithyroid drugs may also cause a thyrotoxic crisis. The crisis requires immediate intensive care. Left untreated, it can lead to death.
A thyrotoxic crisis can only develop from hyperthyroidism. In thyroid hyperfunction, the thyroid gland produces too many thyroid hormones. The two main thyroid hormones are triiodothyronine (T3) and thyroxine (T4). The basic component of the thyroid hormones is the trace element iodine. The main cause of hyperthyroidism is the autoimmune disease Graves' disease.
The body's own antibodies bind to the TSH receptors of the thyroid and thus mimic the action of the thyroid-stimulating hormone (TSH) from the pituitary gland. This leads to a constant production of T3 and T4 and thus to a hyperthyroidism. Hyperthyroidism can also develop through thyroid autonomy. In thyroid autonomy, individual areas of the thyroid gland operate independently of the hormonal regulatory mechanisms.
In addition, hyperthyroidism can be caused by hormone-producing tumors of the thyroid gland and by thyroid inflammation. The thyrotoxic crisis usually develops after a high intake of iodine. This provides the body with more iodine for the production of thyroid hormones. Since the body's own hormonal regulatory mechanisms are disturbed in the thyroid hyperfunction, the production is also not contained.
The thyrotoxic crisis is often induced iatrogenically, ie by the doctor, by the administration of iodine-containing drugs. X-ray-containing contrast agents are also frequent triggers. It also becomes dangerous when patients with hyperthyroidism independently discontinue their medication. Thyreostatic drugs prevent the thyroid from producing too many hormones.
If the medication is discontinued suddenly, it can lead to a thyrotoxic crisis. Even operations can cause a thyrotoxic crisis. In particular, after the removal of thyroid tissue, the thyroid hormone production may increase reactively.
Symptoms, complaints & signs
Typical symptoms of hyperthyroidism include insomnia, irritability, and nervousness. In many patients, a subtle tremor, a slight trembling, is a sign of restlessness. The thyroid hormones stimulate the entire metabolism. The blood pressure is high.
The difference between the systolic and diastolic blood pressure (blood pressure amplitude) is increased. The heart activity is changed. The heart beats faster, in some cases those affected suffer from heart stumbling (extrasystoles). Atrial fibrillation can also be the result of hyperthyroidism. The patients are hungry because of the increased energy expenditure, but still lose weight.
Due to the mobilization of glycogen reserves and fat reserves overgrowth (hyperglycaemia) may occur. Patients sweat fast, are warm-tolerant and have a moist, warm skin. You will need to visit a toilet more often and have a thin chair. The muscles are weak. In thyrotoxic crisis, all of these symptoms increase massively and within a short time.
At stage I of the thyrotoxic crisis, the heart rate is increased to more than 150 beats per minute. The patients vomit and have a high fever. Due to the increased fluid excretion an exsiccosis can develop. In Stage II of the crisis, patients are increasingly disoriented and dimmed in consciousness. You are dizzy or sleepy. In stage III, the patients fall into a coma.
Particularly threatening are the increased heart rate, cardiac arrhythmias and dehydration. Untreated, the coma threatens irreversible long-term consequences. Overall, the prognosis of the thyrotoxic crisis is rather poor. It often ends fatally.
Diagnosis & disease course
A suspected diagnosis can be made quite quickly based on the characteristic symptoms. The crucial indication provides an already known hyperthyroidism. The elevated thyroid levels can be detected in the thyrotoxic crisis in the blood. The TSH value is greatly reduced.
TSH stimulates the thyroid gland to produce thyroid hormones. However, since the thyrotoxic crisis causes far too many thyroid hormones in the blood, the pituitary gland produces less TSH. The levels of thyroid hormones T3 and T4 are still elevated.
If a thyrotoxic crisis occurs, it affects the entire metabolism. The blood pressure is increased, it comes to nervousness, irritability and sleep disorders, and a trembling occurs. In addition, the heart activity is changed and those affected suffer from heart stuttering and atrial fibrillation - both can lead to serious complications to heart failure.
Accompanying the general symptoms is the loss of weight, which is usually associated with dehydration and deficiency symptoms. The mobilization of glycogen and fat reserves can lead to hypoglycaemia. In addition, the patients are physically damaged and suffer from muscle weakness. In thyrotoxic crisis, all these symptoms increase in no time. Relatively fast it comes to high fever, dehydration and disturbances of consciousness.
Afterwards, the patients fall into a coma. A loss of consciousness in the absence or too late treatment usually irreversible long-term consequences or even death. The treatment of a thyrotoxic crisis may be affected by the typical side effects and interactions of prescribed drugs. Thus, a surgical procedure is always risky because the patient is usually already significantly weakened.
When should you go to the doctor?
A high blood pressure, an inner restlessness, nervousness and irritability are complaints that should always be clarified by a doctor. If you continue unchanged for several weeks or months, they must be examined. In the event of an increase in irregularities, a doctor's visit is required immediately. If it comes to disorders of the heart rhythm, a decrease in muscle strength or a loss of overall resilience, consultation with a doctor is recommended. Fever, vomiting, feeling unwell and a feeling of sickness should be presented to a doctor. Since the thyrotoxic crisis is a health emergency, acute changes in well-being often occur within a short time.
In the event of sudden discrepancies, an ambulance service should be alerted. Characteristic of the disorder is that in advance, those affected lose weight, although they absorb an unusually high daily calories. An unwanted weight loss is an alarm signal from the body. In the case of disturbances of consciousness, disorientation and disturbances of memory activity, an ambulance service must be called. Present persons are obliged to apply first aid measures. Without a timely and professional medical care, the person threatened a comatose state and irreparable damage to organs. Therefore, there is an acute need for action when it comes to a significant deterioration of health.
Treatment & Therapy
The thyrotoxic crisis is always treated in the intensive care unit. The functions of the cardiovascular system are closely monitored. In addition, the fluid intake and the fluid excretion are monitored. Thus, a fluid balance can be carried out and counteracted exsiccosis. Those affected receive three to four liters of fluid per day. In addition, drugs are used that limit the production and secretion of thyroid hormones.
These include antithyroid drugs such as thiamazole and glucocorticoids such as prednisolone. Beta-blockers regulate the increased heart rate. Strong fever can be cooled with ice bags. Paracetamol or ibuprofen can also reduce the fever. If patients suffer from severe restlessness, sedation may be used.
If the thyrotoxic crisis is triggered by iodine contamination and none of the measures described helps, the thyroid gland is almost completely removed during a surgical procedure. Also, plasmapheresis can be performed to remove the iodine from the blood.
Consistent treatment of hyperthyroidism can usually prevent a thyrotoxic crisis. Patients with known hyperthyroidism should not take high-iodine medications. Even in special situations, such as infections or surgery, the thyroid function should be controlled.
Unlike thyroid hyperfunction, the thyrotoxic crisis poses a life-threatening threat. It does not develop chronically, but assumes a fulminating course. As a rule, however, the crisis is preceded by hyperthyroidism. Timely medical intervention is necessary to prevent a fatal outcome of the disease.
In such cases, treatment and follow-up work in parallel. The aim of the therapy is a normalization of the thyroid levels as well as a prevention of the life-threatening condition. The mortal danger is not the same for every thyrotoxic crisis. At the early stage, a lethal outcome of about 10 percent is likely, while in the advanced stage the probability is already 30 percent.
As a last option, in severe cases, only the surgical reduction of the thyroid gland. However, immediate treatment is always necessary. The patient is admitted to the hospital for this purpose. In the allocation of appropriate medicine, the responsible internist checks the cure. In addition, the sufferer receives medication for other complaints such as nausea or dizziness.
If the crisis has been successfully contained, aftercare will be phased out and end with discharge. In thyroid surgery, the usual aftercare procedures are scheduled. Occasional follow-up checks are carried out by the family doctor. The patient must be aware of the appointments so that possible new changes in the thyroid can be detected early.
You can do that yourself
The thyrotoxic crisis is a medical emergency, as the condition of the patient's health rapidly deteriorates and can eventually lead to death. It is therefore of paramount importance that patients do not try to relieve their condition by self-help measures. This is not possible and increases the risk of dying as a result of the thyrotoxic crisis.
If you find yourself having symptoms of a thyrotoxic crisis or have any other symptoms, contact an emergency doctor immediately. As soon as they receive medical treatment, patients with a thyrotoxic crisis follow all the instructions of the staff, whether they are doctors or nurses.
People with a thyrotoxic crisis usually first go to a clinic and are treated in hospital until their health improves again. Patients receive appropriate medication in a prescribed dose. Regular and proper use of these medicines is essential because otherwise the symptoms may recur. Indigestion is also treated with medication, and patients receive adequate meals in the hospital. Since many sufferers suffer from nervousness, sedatives are sometimes used.