general anesthetic

definition

General anesthesia is a procedure that is used during surgical interventions and through which the patient is completely unconscious, during which independent breathing is suspended.

Applications

General anesthesia is always used when long and complex procedures are involved or when there is a risk that the patient's restlessness will endanger the surgical procedure.
In addition, general anesthesia must be carried out if the surgical procedure requires complete relaxation of the striated muscles.
In procedures where muscles have to be cut, it is necessary that the tone of the muscles is reduced and these relax. This is only possible with general anesthesia. With local anesthesia, the patient's muscle strength is usually retained during the procedure. It is therefore extremely difficult for the surgeon to surgically penetrate deeper tissue layers because the tension in the muscles counteracts this.

A surgical procedure always means one for a patient huge Stress factor. If major abdominal surgery were not performed under general anesthesia and if the patient were fully conscious but not in pain, this would mean a considerable stress factor (noticed or unnoticed) for the patient.

General anesthesia can now Timed quite precisely adjusted become.
With short interventions, the patient wakes up again quickly, with longer operations he is kept unconscious for longer.

In addition to the surgical interventions, general anesthesia are always used when illnesses or injuries are so severe that the patient's consciousness is mainly through the Sympathetic the patient's prognosis would worsen.
Patients whose Inadequate breathing has become and the need for one Ventilation given, are always placed under general anesthesia, as the patients would not tolerate the procedures used if they were fully conscious. Keeping a patient calm and reducing body functions can be necessary in severe cases.

Duration of general anesthesia

The duration of the effect of general anesthesia is variable and depends on the procedure or the indication.
It is possible to use general anesthesia for 10 minutes for small operations or up to 12 hours for long operations.
If a patient is to be kept under controlled general anesthesia due to a serious illness, anesthesia periods of several weeks are possible.
The condition, also known as an artificial coma, can theoretically be maintained indefinitely if the corresponding body functions are constantly monitored and anesthetic agent is continuously given.
The longer a general anesthetic is performed, the longer it usually takes to drain the general anesthetic.
In this procedure, also known as weaning, the drugs that lead to general anesthesia are reduced bit by bit and at the same time care is taken to ensure that the body takes over more of its functions itself. If this does not succeed, which can always be the case with long anesthesia lasting several days or weeks, the general anesthesia must be renewed and weaning accordingly.

General anesthetic procedure

Preparation for general anesthesia

In order to be able to carry out a surgical procedure undisturbed, on the one hand the consciousness of the patient must be switched off during this time, furthermore the pain sensations must be reduced and, thirdly, the muscles must be relaxed in order to be able to carry out corresponding surgical interventions.

General anesthesia begins with patient education. It includes the duration of general anesthesia and the reason, as well as a detailed description of the implementation and the risks and side effects of general anesthesia.
In general, general anesthesia is given the day before the operation.

The patient must sign the relevant documents and confirm that they agree to the anesthesia and that they have been informed about the procedure.

Read more on the topic: Fear of anesthesia / general anesthesia

Do you have to be sober?

With general anesthesia, the general rule is that the patient must be sober. Specifically, this means that the last solid meal should be six hours ago and nothing should be drunk two hours before the anesthetic. In infants, there should be four hours between breastfeeding and induction of anesthesia. Failure to follow these rules increases the risk of anesthesia, as the patient may vomit and this vomit can be inhaled. In an emergency, this rule is ignored, as the operation is more important than protection from possible complications.

Induction of anesthesia

The patient must be sober on the day of the operation.
He is then taken to the operating theater and then to the induction room. He is given a large venous access through which appropriate infusions run.

Furthermore, he is monitored and his pulse, blood pressure and heart rates as well as oxygen saturation are permanently monitored and recorded. The patient is still awake and has a mask held in front of his nose through which he has to breathe oxygen. This saturates the blood with oxygen. The patient is then injected with a drug that removes the wakefulness and lets him fall asleep.
This is followed by the administration of the muscle-relaxing drug. As a result, the breathing muscles no longer work and the patient loses the ability to breathe independently. Since the blood was previously saturated with oxygen, a short respite is not a problem.

For the procedure, the patient is intubated and a tube is inserted into the windpipe. This hose is attached to a ventilator and supplies the now deeply sleeping patient with sufficient oxygen. Ventilation can also take place through a ventilation mask that is placed in the pharynx. Alternatively, the anesthetist can ensure continuous manual ventilation with a mask and a resuscitator for short anesthesia.

Read more on the topic: Intubation anesthesia

Maintaining general anesthesia

To maintain general anesthesia, the patient is usually given the drug Propfol today.
A certain amount of medication per hour can be injected into the patient at regular intervals via the venous access and a so-called perfusor.
This prevents the patient from waking up. Although the patient has now lost consciousness and is no longer breathing independently, he still feels pain. In order to be able to start the procedure, he is now given a pain reliever in the vein, also at regular intervals.

With this triple combination of drugs, the patient is sufficiently anesthetized and the procedure can begin. This method of general anesthesia, in which all medication is given through the vein, is also known as total intravenous anesthesia.
There is also the possibility of maintaining the sedative effect on the patient with a gas mixture. The gas previously known as laughing gas is no longer used today due to its poor controllability. Today there are a number of other gas mixtures e.g. Halothane, which is used to maintain anesthesia. With this anesthetic procedure, the gas mixture is then permanently applied to the patient via the airways during the procedure.

Diversion of general anesthesia

The anesthetist is next to the patient during the entire operation and monitors the vital organ systems. He discusses with the surgeon and is informed about the approximate end of the operation.
Shortly before the end of the operation, the amount of anesthesia the patient receives is reduced. It usually still takes some time for the anesthetic to leave the body washed out has been.

The patient is asleep until then and needs ventilation. As a rule, the last sutures of the operation can still be performed, even if the anesthetic has already been turned off. The administration of painkillers usually continues. The next step is to reduce the muscle relaxing drug. As the ability to breathe on their own regains, the patient usually begins to breathe against the tube that is still in the lungs. The anesthetist closely monitors the oxygen saturation of the blood at this point in the general anesthesia.

If the saturation is not yet sufficient, the patient will continue to be ventilated for a while. With regained breathability, the patient tolerates the tube less and less. When this stage occurs, the tube is pulled. Additional mask ventilation can help to compensate for any oxygen deficit at this point.
The patient is then pushed out of the operating room and taken to a recovery room, where he is monitored for some time.
If his general functions are stable, he is brought to the ward.
The general anesthetic is now over.

Wake up time

The time to wake up is defined as the period from when the anesthesia is released until it is completely restored to normal and normally lasts one to three hours.

The time it takes to become fully awake is mainly influenced by the size and type of the operation, the choice of anesthetic agent and the individual previous illnesses. Damage to the liver or kidneys, for example due to a delayed breakdown of the narcotic substances, leads to a longer time to wake up.

During the wake-up time, the patient is usually in a recovery room, which is often connected to the operating theater. This is important because you need to monitor your circulation and breathing until you are fully awake. Only after the end of the wake-up time is the patient transferred back to the normal ward or the intensive care unit, depending on the situation.

Side effects

Like almost every medical procedure, general anesthesia is not free from side effects.
Although we now have a lot of experience with the procedure and it is well tolerated in the majority of cases, the most important side effects should be pointed out. The form and severity of side effects after general anesthesia depends on many factors.
Older people or those with previous illnesses are particularly susceptible to this, but overall different risk factors can have an influence.

Read more on the topic: Risks of anesthesia

In general, side effects such as brief confusion and drowsiness occur immediately after waking up after general anesthesia. Orientation is difficult at first. However, these side effects are normal and do not last long.
A very frequently observed side effect is PONV. This abbreviation stands for "postoperative nausea and vomiting"what too German"postoperative nausea and vomiting"means. This extremely unpleasant but generally harmless side effect is described in 20-30% of patients after general anesthesia and does not last long.
Some risk factors favor the occurrence of PONV. Children and adolescents, women and people who suffer from motion sickness are more likely to experience nausea and vomiting after general anesthesia.
With potent drugs such as dexamethasone, antihistamines and setrons, which are used against nausea, the symptoms can usually be controlled well.
Also, prophylactically before general anesthesia, medication is often given to prevent the occurrence of PONV. The mechanism of its formation is not yet fully understood.
What is certain is that certain anesthetics and drugs used during anesthesia can stimulate certain receptors in the brain, which trigger the body's own protective reflex against toxic substances.

A second side effect often seen after an operation with general anesthesia is hypothermia with postoperative tremors (Shivering). As the name suggests, the patient has an excessively increased sensation of cold.
One cause could be temporary hypothermia during general anesthesia. In response to this, the body tries to produce heat with the muscle tremors and counteract hypothermia.
However, other causes are also discussed, so that the process behind it is not really understood here either. The frequency is given as 5-60%.
To treat these side effects, on the one hand, calming agents are available; on the other hand, warming blankets and warmed infusions can help the body to develop heat.

Since general anesthesia involves drugging deeply into the consciousness and the complex structure of the brain, various types of cognitive side effects can occur after general anesthesia. These side effects mainly affect the elderly.
First of all, the postoperative delirium should be mentioned here, which is divided into a hyperactive and hypoactive form, depending on the increased or decreased arousal and activity.
After general anesthesia, consciousness and cognitive attention are limited. Disturbances in memory can occur and the patient's temporal and spatial orientation can be impaired.
Sleep disorders and general restlessness are described as further side effects. Sometimes there may be slight hallucinations or delusions. The frequency of delirium is given as 5-15% and sometimes significantly different forms.
If side effects such as poor concentration only appear after days or months, one speaks of cognitive dysfunction, which can last for a long time and in the worst case be permanent.

In addition to these side effects, which are limited to the central nervous system, there are also a number of side effects with general anesthesia that can occur organ-specifically due to the methods and instruments used.
Since artificial ventilation is used during general anesthesia, mechanical pain and irritation of the oral cavity, throat and vocal cords can occur postoperatively from an inserted tube. Difficulty swallowing after general anesthesia can also occur. Teeth are rarely damaged during intubation, i.e. when the ventilation hose is inserted into the windpipe.
Because of the positioning of the patient during the operation, damage to nerves with resulting sensory disturbances or numbness is conceivable. Since several accesses are made in the veins or arteries with general anesthesia, bruises are possible at the puncture sites.

The side effects described are possible, but none of them have to occur. Overall, thanks to modern anesthetics and well-researched concomitant medication, general anesthesia is now a well-tolerated procedure with few side effects. However, if there are any, you can usually get a grip on them.

Read more on the topic: Side effects of general anesthesia

Risks

General anesthesia is a major interference with the normal processes in the body and therefore also carries some risks. A risk with general anesthesia is a potentially difficult ventilation situation. This means that the supply of oxygen is not guaranteed. Reactions of the cardiovascular system to the anesthesia are also possible and occur particularly in people with previous illnesses.

Basically, the risks of general anesthesia depend on the previous illnesses, age and general condition of the patient. Due to modern monitoring technology, serious consequences of anesthesia and death from anesthesia are becoming increasingly rare and are currently around 0.008%. High-risk anesthesia are emergency anesthesia in particular, as detailed anesthesia planning is not possible and the patient is usually not sober. Minor side effects of anesthesia, such as a sore throat, hoarseness and nausea, are relatively common and usually go away on their own. This also applies to the continuity syndrome, a postoperative confusion that particularly affects older patients.

aftermath

The after-effects of general anesthesia are not as drastic these days as they used to be.
The modern anesthetics can be dosed significantly lighter and lower so that the treated patients are significantly faster again after waking up as before the anesthesia. The duration of the side effects and after-effects of anesthesia are usually only of short duration.

This is due to the fact that previously only anesthetic gases were used, which had to be dosed in very high doses to relax the muscles.

Nowadays, separate drugs are administered intravenously for muscle relaxation so that the anesthetic drugs do not have to be dosed as strongly.

Although post-anesthetic nausea has become less common, this aftereffect is still relevant today.
The most common is an irritated throat area and stressed vocal cords, which can be attributed to the ventilation hose used during anesthesia, which is pushed into the trachea past the vocal cords. However, this feeling usually improves a few hours after the operation.

General confusion and sleepiness are also normal after general anesthesia, but they improve relatively quickly after the procedure.

It is important that after the general anesthesia, the use of heavy equipment, and thus driving a car due to the drugs used, is not allowed.

Read more about the topics: Aftermath of general anesthesia

Consequences for the brain

The brain is under considerable stress during general anesthesia. About a third of those operated on, after general anesthesia, especially with anesthetic gases, develop a state of confusion after general anesthesia. However, in most cases, this will decline within hours to days. The elderly and people who have had a stroke or impaired blood flow to the brain are at greater risk for these consequences. In rare cases, dementia can develop permanently. Furthermore, a study has shown that children who have had general anesthesia before their first birthday show, on average, poorer memory performance than their peers who have not been operated on.

Tooth damage

During intubation, the placement of the ventilation tube, the anesthetist uses a metal spatula to lift the lower jaw and tongue. This is necessary in order to gain free access to the windpipe. A slight effort is required here. If this spatula slips or is pried incorrectly, it can bump into the teeth, causing damage to the teeth. This can sometimes not be prevented, even if the intubation set is used correctly, as the focus is on the patient's ventilation situation. For prevention, silicone splints can be placed between the teeth and the spatula.

Sore throat and hoarseness

The person concerned does not breathe independently during general anesthesia. This task is performed by a ventilator, which the anesthetist monitors. In most general anesthesia, a breathing tube is inserted into the windpipe for this type of ventilation. This ventilation hose must be passed through the glottis and can irritate the vocal cords and the entire pharynx. Therefore, sore throats and hoarseness are frequent but short-term consequences of general anesthesia.

Alternatives to general anesthesia

There are numerous ways to switch off the sensation of pain during an operation. One possibility here is local anesthesia, in which an anesthetic such as lidocaine is injected directly into the area of ​​the procedure. However, this can only be used for small interventions, such as sewing a laceration.

The next possibility is the conduction pathway anesthesia, in which the responsible nerve is numbed well above the affected area. This method is particularly used for operations on the hands and feet. A typical anesthetic for a caesarean section is the spinal anesthesia. Here, the anesthetic is injected directly onto the spinal cord, numbing the entire body area below the area of ​​responsibility of this spinal cord site.

In many cases, however, general anesthesia is still the only viable option. Particularly major and emergency operations make general anesthesia irreplaceable.

Are you interested in alternatives to general anesthesia? Read more here:

• Types of anesthesia - which are there?
• Mask anesthesia

General anesthesia at the dentist

Under certain circumstances, during dental treatments, it can be useful to perform the planned procedure under general anesthesia.

In particular, patients who are very scared when visiting the dentist can be helped with general anesthesia during treatment.

But also long operations or treatments that are difficult to provide with local anesthesia are usually carried out using general anesthesia.

As with any general anesthetic, general anesthesia at the dentist's aim is to deprive the patient to be treated of the consciousness and the pain sensation and to let the muscles relax.

The anesthetic drugs can be administered either with gases through the lungs or as liquid medication through the veins. A combination of both methods is also possible.

The method chosen depends on the patient's preferences and age as well as the individual treatment.

During anesthesia, breathing air is fed into the lungs via a so-called tube in order to supply the patient with oxygen during the treatment period.

Depending on the duration of the treatment, the depth of the anesthesia can be adjusted so that nowadays relatively short operations can be performed using general anesthesia.

After the operation, a state of consciousness is reached and the ventilation tube is removed.

The side effects of general anesthesia are now much lower than they used to be. Nonetheless, nausea and an irritated throat and irritated vocal cords from the ventilation tube after anesthesia can occur.

It should also be noted that after a general anesthetic, the use of heavy equipment, and thus driving a car, is not permitted.

Read more on the topic:

• Local anesthesia at the dentist
• General anesthesia for a wisdom tooth operation

General anesthesia during pregnancy

In certain situations it may be necessary to give a pregnant woman general anesthesia in order for surgical procedures to be performed.

If it can be prevented and surgery can be done after pregnancy, general anesthesia is usually not done during pregnancy.

Nevertheless, it is possible to use general anesthesia in surgical emergencies, for example appendicitis or after accidents.

The drugs and anesthetic gases used, however, have to be changed slightly compared to general anesthesia in non-pregnant women, as certain drugs are suspected of causing deformities in the child.
However, these drugs are known and are no longer used in pregnant women under general anesthesia.

For this reason, it is important to inform the treating physicians about the pregnancy.

It should be noted that the risk of premature birth increases depending on the individual length of pregnancy.

The child's condition is constantly monitored during the operation using separate devices, so that the medication and dose can be adjusted during the operation if necessary.

Read more on the topic: Anesthesia during pregnancy

General anesthesia possible despite a cold?

Before each anesthesia, there is a detailed discussion with an anesthetist, who reports on the dangers and the course of the anesthesia.
In this conversation, the person to be treated is also asked about their current state of health.

If there is an acute cold, the anesthetist must be informed about it before the operation.

In many cases, a cold is not a reason not to perform the procedure, although it always depends on the individual severity of the disease.

The situation is different if there is an increased temperature due to the viral disease, in which case the date of the operation will be postponed if possible.

Overall, this is recommended for elective surgery in the event of a severely impaired state of health.

If it is a surgical emergency, a cold is not a reason not to perform the operation. If possible, the treating physicians should also be informed in these cases about the presence of an infection in order to change the medication or its dose if necessary.

Read more on the topic: General anesthesia despite having a cold

General anesthesia for a caesarean section

Of the Caesarean section represents an operative way to bring the child into the world.
This is done by means of a Lower abdomen cut and the Opening of the uterus took the child out of the mother's womb.

Such an intervention must always be carried out with a anesthesia accompanied.
It is available for this purpose, however different procedures for a painless birth by caesarean section.

The choice of what type of anesthesia is performed depends mainly on the person Planability of the intervention as well as the mental stability from the mother.

A so-called Spinal anesthesia or Epidural anesthesia, Anesthetic procedures in which the drug is close to the Spine injections come into consideration, especially if the caesarean section is performed beforehand planned has been.

At a not planned Caesarean section, for example if it becomes apparent shortly before delivery that a classic birth is not possible via the birth canal, often becomes a general anesthetic initiated.

It makes no difference to the child which anesthetic method is used during the operation.
The main difference is that with spinal or epidural anesthesia the Mother stays awake, whereas this is not possible with general anesthesia.

Studies suggest that the level of safety in the choice of anesthesia method differs only insignificantly from one another and therefore mostly the personal preference the mother as well as the anesthetist and the individual health status is decisive for the choice of anesthesia used.

General anesthesia in children

Nowadays, children can also be given general anesthesia without any problems if certain operations require it.

However, the technique used is minimally different from that used in adult patients.
Depending on the age of the child to be treated, general anesthesia is induced intravenously (in older children) or by means of inhalation anesthetics (in younger children).
Above all, the wishes of the child are taken into account, with older children mostly agreeing to the injection required for intravenous introduction into a vein while awake.

As with adult patients, the dose of medication used is calculated based on weight to rule out overdose.

Recently, based on a new study, there has been a lot of discussion about whether general anesthesia can be harmful to the child.
A study from the USA claims that general anesthesia in early childhood permanently changes the memory performance of these children 25% decreases.

The German Society for Pediatric Surgery (DGKCH) however, after the publication of the study, stated that the evidence for the assertion in the study was very thin and only contributed to uncertainty among doctors and parents of the children being treated.

If operations are necessary, the procedure should not be dispensed with, as children can usually benefit greatly from performing the procedure.

However, if it is an operation that can also be performed when the affected child is older, the operation should be postponed by a few months or years if possible.

In any case, a detailed discussion with an anesthetist and the surgeon performing the operation should take place before the operation.

Read more on the topic: General anesthesia in children

General anesthesia for dementia

General anesthesia is always associated with an increased risk in dementia patients. This already comes into play when planning anesthesia, as those affected cannot give any reliable statements about their previous illnesses and medication. In addition, rules such as the fasting time before anesthesia are difficult to implement for those affected. People with dementia have an above-average rate of continuity syndrome. This is an increased state of confusion after anesthesia, which disappears within a few days. In some cases, dementia worsening after surgery has also been reported.

costs

For major operations that require general anesthesia, general anesthesia is covered by all health insurance companies. For operations where general anesthesia is not absolutely necessary partially paid by myself become. These include, for example, wisdom tooth operations. In this case, general anesthesia costs around € 250 for the first hour and around € 50 for each additional half hour. In addition, however, an inpatient stay may be necessary in some cases, which would not be necessary with local anesthesia.

History of anesthesia

Anesthetics have been given for hundreds of years.
The first anesthetics were gases that were administered to the subjects. They were difficult to control and caused many deaths.
The most famous anesthetic in history was ether, which was used in 1846.
Laughing gas was then used around 1869.
The use of anesthetic in the form of intravenous drugs first came into play in the mid-19th century. Anesthetics are constantly being further developed in order to achieve even better controllability and a reduction in side effects for the patient.

Summary

General anesthesia is a procedure in which the patient's consciousness as well as the sensation of pain and the control of muscle movements are eliminated.
General anesthesia is always used when a major surgical procedure has to be performed or when the patient has to be put into an artificial deep sleep due to the severity of his illness in order to be treated better.
Before the induction of anesthesia, the patient is informed and informed about the process and possible risks and side effects.
Induction of anesthesia usually begins on the following day when the patient is sober. First he has to breathe oxygen through a mask to saturate the blood. Then he is given a sleep-inducing drug and a muscle-relaxing drug via a venous access. With its effect, the patient's ability to breathe on their own disappears.He is intubated and supplied with a ventilator.
He is also given a pain reliever through the vein.
All drugs are injected fully automatically at regular intervals using a pump.
The vital signs and vital functions are continuously monitored during the procedure.
If all medication is administered through the veins, one speaks of total intravenous anesthesia (TIA).
There is also the option of giving sleep-inducing drugs in the form of gas during the procedure.
When the surgical procedure is over, the medication supplied is throttled again. First, the anesthetic is reduced, then the muscle-relaxing drug after the operation is complete.
Once the patient regains their breathing ability, they will be extubated and taken to a recovery room under supervision.
General anesthesia have become low-risk today. People often complain of nausea and aspirations occasionally.
The life-threatening malignant hyperthermia is a rarity in anesthesia today.