anesthesia

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Anesthesia is a method of creating artificial sleep. It is also called general anesthesia. General anesthesia leads to loss of pain perception and loss of consciousness. It enables major operations and examinations. In colloquial language, however, regional forms of anesthesia are sometimes also referred to with the word anesthesia. Read how the different forms of anesthesia are used and what risks they entail!

What is anesthesia?

With the help of anesthesia, patients can be put into an artificial sleep. For this, the responsible specialist (anesthetist) uses various drugs and / or gas mixtures.

Anesthesia enables operations and certain examination procedures that would otherwise only be possible with extreme pain. There are different procedures that differ, among other things, in terms of the anesthetic side effects and areas of application.

Inhalation anesthesia

In the case of inhalation anesthesia, the anesthesia is caused by inhaling gaseous medication, for example sevoflurane, isoflurane or nitrous oxide. These so-called volatile anesthetics switch off consciousness on the one hand, but also reduce the sensation of pain.

Inhalation anesthesia is the oldest form of anesthesia and is now mostly combined with other methods. Inhalation anesthesia alone is occasionally used in children.

Total intravenous anesthesia (TIA)

During this anesthetic procedure, the doctor injects all the necessary anesthetics into a vein. From there they first get to the heart and then into the entire bloodstream.

Balanced anesthesia

Balanced anesthesia combines the two procedures mentioned. At the beginning of the anesthesia, the patient usually receives intravenous medication, and during the operation he also breathes in anesthetic gases. This reduces many side effects of anesthesia and the consumption of strong pain relievers.

Further information: local anesthesia

For some operations it is sufficient if only the sensation of pain is switched off in a certain area. More on this under local anesthesia.

Further information: Spinal anesthesia

In a special form of local anesthesia, the anesthetic is injected into the spinal canal. You can find out more about this in the text Spinal Anesthesia.

Further information: epidural anesthesia (PDA)

There is another way to switch off the sensation of pain close to the spinal cord. Read all about it in the article epidural anesthesia.

When is an anesthetic performed?

Anesthesia is always used when it is necessary to prevent pain and stress in the patient. Depending on the severity of the procedure, the doctor can adjust the intensity of the anesthesia.

Operations

The most common reason for anesthesia is surgery. Many interventions, for example on abdominal organs, are only possible in this way. The reduced awareness also reduces the patient's stress and promotes recovery after surgery. The anesthetic also gives the surgeon the best possible working conditions because the patient does not move. This is very important for surgery on the brain or on blood vessels, for example.

Investigations

Some examination procedures also require anesthesia. For example, during a bronchoscopy with a rigid tube via the trachea, the patient would experience severe pain and coughing if he were not anesthetized. But even babies who have to have magnetic resonance imaging are often given anesthesia so that they can lie still. Otherwise the recorded images would be blurred and unusable.

A short anesthetic is usually sufficient for such examinations. In contrast to anesthesia during operations, you only give a sleeping pill in a low dose.

Emergency medicine

If a patient is unable to breathe independently, for example after a cardiac arrest, a serious accident or an allergic reaction, they must be artificially ventilated. On the one hand, anesthesia makes it easier to carry out ventilation safely and, on the other hand, it relieves the pain that unconscious patients still feel.

What do you do with anesthesia?

For the anesthesia, the anesthetist uses gas-air mixtures and various drugs. These can be divided into three groups.

  • Hypnotics (sleeping pills) primarily switch off consciousness. One example is propofol.
  • Analgesics (pain relievers) suppress the sensation of pain. Strong analgesics from the group of opioids are given for anesthesia.
  • Muscle relaxants relax the muscles and make the patient unable to move. Depending on the application, they do not have to be used for every anesthetic.

Certain hypnotics can, depending on the active ingredient and the dose, also have a partially pain-suppressing and muscle-relaxing effect.

Anesthesia education

Before the planned anesthesia, the anesthetist informs the patient about the intended procedure in a detailed discussion. He also asks about previous illnesses and inquires about drugs he takes regularly. In this way, the doctor assesses the risk of anesthesia and selects suitable medication. If he is very restless and afraid of anesthesia, he also gives a sedative so that the patient can relax.

Induction of anesthesia

Before induction of anesthesia, the patient inhales pure oxygen for several minutes. This creates an oxygen reserve in the blood for the subsequent insertion of the ventilation tube (intubation). At the same time, the doctor places a needle in the patient's vein, for example in the hand, through which he can inject the medication. A strong pain reliever is followed by a high-dose sleeping pill, which causes the patient to lose consciousness within a few seconds and stop breathing on their own.

The anesthetist then resumes ventilation using a tight face mask and a resuscitator bag. If this works without any problems, he injects a muscle-relaxing drug. As soon as it works, he can insert the ventilation hose (tube) into the windpipe, through which the patient is from now on ventilated by a machine.

During longer operations, the patient is warmed with a fan heater, otherwise the body would cool down quickly. A monitoring monitor also continuously shows important vital functions such as blood pressure, pulse, heart activity and breathing rate. In this way, the anesthetist can quickly identify possible anesthetic complications.

Rapid sequence induction

A special form of anesthesia induction is the so-called Rapid Sequence Induction (RSI). Here, the anesthetic medication is administered in quick succession and there is no need for mask ventilation in the meantime. It is mainly used in patients who have not fasted, pregnant women and patients with certain gastrointestinal diseases and prevents stomach contents from flowing back into the windpipe.

Anesthesia continuation and diversion

With the help of automated syringe pumps or anesthetic gas vaporizers, the patient receives the medication they need for a deep sleep and freedom from pain until the end of the operation or examination. The anesthetist constantly monitors the cardiovascular activity. When the anesthesia is to be stopped, he stops the flow of anesthetic gases and medication and waits for the patient to wake up. Then he pulls the tube out of his windpipe and sucks saliva from his throat. In this way, the patient can breathe independently again.

After the operation, the patient is monitored in the recovery room. A doctor is always available there to administer painkillers if necessary and to assess the patient's vital functions.

What are the risks of anesthesia?

General anesthesia carries the risk of many side effects. Anesthetic medication can lead to sudden drops in blood pressure or cardiac arrhythmias, among other things. The anesthetist then treats this with medication to support the circulatory system. All drugs used can also cause severe allergic reactions.

Ventilation problems

If it turns out during the induction of the anesthesia that the patient cannot be ventilated through a tube, the doctor has to perform a tracheotomy in the worst case. Another danger is that stomach contents flow back into the windpipe and lungs. The acidic gastric juice could cause severe pneumonia. Patients who have not sobered as part of a Rapid Sequence Induction are particularly at risk.

One possible complication is tooth damage, as the doctor uses a special instrument (laryngoscope) to insert the tube into the windpipe. Dental prostheses are therefore removed before the operation. The tube itself can also cause damage to the vocal folds (vocal cords).

Malignant hyperthermia

Malignant hyperthermia is a dreaded muscle disease that can appear very suddenly during anesthesia. The entire musculature is permanently tense, so that the body warms up in a life-threatening manner. In addition to genetic factors and certain anesthetic gases, the muscle relaxant succinylcholine is a possible trigger.

In contrast to the anesthetic gases, the purely intravenous anesthesia is not a trigger for malignant hyperthermia, which is why it is also referred to as trigger-free anesthesia.

Wakefulness during anesthesia

Medical professionals speak of intraoperative wakefulness when the patient suddenly wakes up during anesthesia or can later remember details of the operation. Reasons for this include sleeping pills that are too low. Patients rarely feel physical pain, but the experiences during the waking phase put a heavy strain on the psyche.

Anesthetic aftermath

Anesthetic side effects can occur even after an operation. These include:

  • Vomiting and nausea after anesthesia (postoperative nausea and vomiting = PONV)
  • Tremors from hypothermia
  • confusion

Vomiting and nausea are common after-effects. Anesthetic drugs, especially anesthetic gases and a long operation time, are among the risk factors. However, by giving certain medications before the anesthesia, you can often prevent subsequent nausea.

Storage damage

Because the patient cannot move and the muscles are completely slack, it sometimes happens that nerves are damaged by lying on the operating table. The arms and lower legs are particularly often affected. The consequences range from tingling sensations to thermal sensation disturbances to complete paralysis. Attempts are therefore made to avoid pressure points by adequately cushioning the patient during positioning.

What should I watch out for after an anesthetic?

It is normal to feel a little confused and sleepy after anesthesia. However, if you experience pain, nausea, and discomfort in your arms, or if you are hoarse for a long time, you should tell the doctor. In consultation with him, you can also take a few sips of water again. When exactly depends on the type of procedure.

If you developed malignant hyperthermia during the anesthesia, the anesthetist will issue you with an emergency ID card.You must always carry this with you so that the anesthetists can choose the right anesthetic for you during a later operation.

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