Shock is an emergency medical condition in which the blood pressure drops so much that not enough blood reaches the body's tissues. Organ damage and death can result.
In ordinary language, we use the term ‘in a state of shock’ for when someone has experienced a frightening event or has heard emotionally upsetting news. But in the strict medical sense, shock has a different, and quite specific meaning.
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What is shock?
When doctors say someone has ‘gone into shock’, what they mean is that the person’s blood pressure has dropped suddenly and drastically. When this happens, the cells don't receive enough blood – and therefore, not enough oxygen. As a result, the cells can become quickly damaged, and the vital organs can’t function normally. Someone in shock requires immediate treatment, or they may die.
What causes shock?
Shock can be caused by any condition that reduces blood flow to the cells. There are different types of shock, due to different causes:
Shock due to low blood volume. The volume of blood in the body may be low, because of severe bleeding or dehydration. Rapid blood loss may occur because of external bleeding e.g. from an accident; or internal bleeding e.g. from a burst blood vessel. Dehydration may result from fluid loss e.g. through severe diarrhoea or not drinking enough liquid.
Shock due to inadequate pumping action of the heart. This may occur after a heart attack, heart failure, or certain other heart problems.
Shock due to extreme dilation of the blood vessels. This may result from head or spinal injury, liver failure, poisoning or an overdose of drugs that dilate the blood vessels. It may also result from a severe allergic reaction, in which case it is called anaphylactic shock. Shock resulting from a serious infection is called septic shock. Toxic shock syndrome is a type of septic shock.
Symptoms of shock
In the early stages of shock, symptoms may not be obvious, and may differ somewhat depending on the cause and type of shock. As the condition progresses, symptoms become more noticeable. Sometimes the only early sign is confusion.
A person going into shock may seem restless and anxious, or, conversely, lethargic and sleepy. The skin feels cold and sweaty, and often looks pale and bluish. When shock results from blood vessel dilation, however, the skin may be warm and flushed at first, and cold, clammy skin and lethargy only occur later on. Usually, breathing is rapid. The pulse is weak and rapid, unless a slow heartbeat is causing the shock. Urine flow is very reduced. The person feels dizzy or faint, and will eventually become unconscious.
What to do if you think someone is in shock
It’s very important for shock to be treated as soon as possible, preferably before symptoms are well established. So if you even slightly suspect someone is going into shock, or has a condition that might cause shock (e.g. they are bleeding, or have a heart condition or severe allergies), then call your doctor or emergency services for advice. If there are any symptoms of shock, then call emergency medical services immediately.
If a person in shock is conscious and you are certain there is no spinal injury, he should lie on his back with his legs elevated about 30 cm to increase blood flow to the heart. The head should be turned to the side to prevent inhalation of vomit. Keep the person warm by covering him with a blanket, and stay with him until help arrives. Don’t give him anything to eat or drink. If you are a trained first-aider, then follow first-aid steps: check the person's airway, breathing and circulation, and keep doing so until help arrives. If necessary, begin rescue breathing and CPR. Any external bleeding should be stopped, if possible.
Treatment and outcome
Emergency treatment generally involves giving fluids and blood intravenously and often medications to improve blood flow. Attempts may be made to increase blood pressure with special trousers that apply pressure to the lower body, driving blood from the legs to the heart and brain. Oxygen is also often given.
The underlying cause of the shock is also dealt with. For example, a heart problem may require drugs or surgery; a bacterial infection will be treated with antibiotics. Most people who have gone into shock will need to be hospitalised, so that their condition can be monitored and they can receive further treatment if necessary. Sometimes, hospitalisation is recommended even in cases where shock is only suspected.
If untreated, shock is usually fatal. If shock is treated, the outlook depends on the cause, other disorders the person has, and how soon appropriate treatment is received. Even with treatment, shock after a massive heart attack or due to septic shock, especially in older people, is often fatal.
The outcome for people who survive shock depends on how severe the condition was, and whether there was organ damage or failure. Some people recover; others may need long-term care and have permanent disability. For example, some people may need dialysis therapy as a result of irreversible kidney failure. During shock, the kidneys are vulnerable to damage from low blood pressure and factors like toxins that build up in the blood, infection and the medications themselves.
Can shock be prevented?
There are ways you can lower your risk for shock, by being informed about preventing its most common causes, such as heart disease, injuries (most commonly, car accidents) and dehydration. If you have a known allergy, then ask your doctor whether it’s necessary for you to carry drugs like epinephrine with you in case of an attack.
Do a course in basic first aid, and know the emergency medical numbers to call: you could save a life.
(Olivia Rose-Innes)
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