Shock | Health Dictionary

Collapse of the circulation resulting in inadequate tissue perfusion to the body cells.
A state of acute circulatory failure in which the heart’s output of blood is inadequate to provide normal PERFUSION of the major organs. It is accompanied by a fall in arterial blood pressure and is characterised by systemic arterial hypotension (arterial blood pressure less than 80 mm of mercury), sweating and signs of VASOCONSTRICTION (for example, pallor, CYANOSIS, a cold clammy skin and a low-volume pulse). These signs may be associated with clinical evidence of poor tissue perfusion, for example to the brain and kidneys, leading to mental apathy, confusion or restlessness and OLIGURIA.

Shock may result from loss of blood or plasma volume. This may occur as a result of haemorrhage or severe diarrhoea and vomiting. It may also result from peripheral pooling of blood due to such causes as TOXAEMIA or ANAPHYLAXIS. The toxaemia is commonly the result of a SEPTICAEMIA in which leakage through capillaries reduces circulating blood volume. Another form is called cardogenic shock, and is due to failure of the heart as a pump. It is most commonly seen as a result of myocardial infarction (see under HEART, DISEASES OF).

If failure of adequate blood ?ow to vital organs is prolonged, the e?ects can be disastrous. The ischaemic intestine permits the transfer of toxic bacterial products and proteins across its wall into the blood; renal ISCHAEMIA prevents the maintenance of a normal electrolyte and acid-base balance.

Treatment If the shock is a result of haemorrhage or diarrhoea or vomiting, replacement of blood, lost ?uid and electrolytes is of prime importance. If it is due to septicaemia, treatment of the infection is of paramount importance, and in addition, intravenous ?uids and vasopressor drugs will be required. Cardiogenic shock is treated by attention to the underlying cause. Full intensive care is likely to be required, and arti?cial ventilation and DIALYSIS may both be needed.



Shock | Health Dictionary

Keywords of this word: Shock


INSULIN SHOCK

Medical Dictionary

A disorder in which the body produces excess INSULIN, which then reduces the amount of glucose in the blood (HYPOGLYCAEMIA). Treatment is with glucose or GLUCAGON. Untreated, the patient goes into a COMA and dies.... Medical Dictionary

SEPTIC SHOCK

Medical Dictionary

A dangerous disorder characterised by a severe fall in blood pressure and damage to the body tissues as a result of SEPTICAEMIA. The toxins from the septicaemia cause widespread damage to tissue, provoke clotting in small blood vessels, and seriously disturb the circulation. The kidneys, lungs and heart are particularly a?ected. The condition occurs most commonly in people who already have a chronic disease such as cancer, CIRRHOSIS of the liver or DIABETES MELLITUS. Septic shock may also develop in patients with immunode?ciency illnesses such as AIDS (see AIDS/HIV). The symptoms are those of septicaemia, coupled with those of SHOCK: cold, cyanotic limbs; fast, thready pulse; and a lowered blood pressure. Septic shock requires urgent treatment with ANTIBIOTICS, intravenous ?uids and oxygen, and may require the use of drugs to maintain blood pressure and cardiac function, arti?cial ventilation and/or renal DIALYSIS.... Medical Dictionary

SHOCK LUNG

Medical Dictionary

See ACUTE RESPIRATORY DISTRESS SYNDROME (ARDS).... Medical Dictionary

SHOCK THERAPY

Medical Dictionary

See ELECTROCONVULSIVE THERAPY (ECT).... Medical Dictionary

TOXIC SHOCK SYNDROME

Medical Dictionary

First described in 1978, this disorder is characterised by high fever, diarrhoea, SHOCK and a rash. It is frequently associated with the use of tampons (see TAMPON), but has occasionally been reported in men. The syndrome may also be linked to the use of contraceptives such as the diaphragm, cap and sponge (see under CONTRACEPTION), and skin wounds or infections may also be a cause. The disease is due to a staphylococcal toxin (see STAPHYLOCOCCUS; TOXINS). Treatment consists of supportive measures to combat shock and eradication of the staphylococcus by ANTIBIOTICS. The design of tampons has been improved. Recurrence of the disorder has been reported and women who have had an episode should stop using tampons and vaginal contraceptives.... Medical Dictionary