What you need to know about general anesthesia

Fast Facts About General Anesthesia

Here are some key points about general anesthesia. More detailed and supporting information can be found in the main article.

The anesthesiologist usually administers a general anesthetic before surgery
There are some risks associated with the use of general anesthetics, but they are relatively safe when used correctly
Very rarely, a patient may experience unintentional awakening during surgery
Side effects of general anesthesia may include dizziness and nausea
The mechanisms by which anesthesia works are still only partially understood.

General anesthetics cause reversible loss of consciousness and analgesia necessary for surgery . The mechanism of action of anesthetics is not fully understood. There are several theories about this.

General anesthesia is essentially a medically induced coma, not sleep. Anesthetic drugs make the patient indifferent and turn off consciousness .

They are usually administered intravenously or by inhalation . Under anesthesia, the patient does not feel pain and may also experience amnesia.

The drugs will be administered by an anesthesiologist, who will also monitor the patient's vital signs during the procedure.

In this article, we'll look at a number of topics, including the possible side effects of general anesthesia, the risks involved, and some theories about how they work.

How long does dental anesthesia last?

On average, the freezing effect lasts 1-2 hours. However, its duration depends on the drug used: for example, injections with Novocaine anesthetize for no more than half an hour, Bupivacaine acts for at least 2 hours. Modern clinics mainly use anesthetics containing Articaine, which freezes tissue for up to 3 hours.

The infiltration anesthesia on the upper jaw will wear off in 45 minutes at most. This is due to the structure of the maxillary bone, which is looser and better supplied with blood.

Freezing after tooth extraction will last longer if the anesthetic contains a vasoconstrictor - a substance that constricts blood vessels and prolongs pain relief.

Story

General anesthetics have been widely used in surgery since 1842, when Crawford Long prescribed diethyl ether to a patient and performed the first painless operation.

On October 16, 1846, American dentist and surgeon Thomas Morton first administered ether anesthesia to a patient to remove a submandibular tumor.

In Russia, the first operation under anesthesia was performed on February 7, 1847 by Pirogov’s friend at the professorial institute, Fyodor Inozemtsev.

Pirogov himself performed the operation using anesthesia a week later. Over the course of a year, 690 operations were performed under anesthesia in 13 cities of Russia, 300 of which were performed by Pirogov!

Soon he took part in military operations in the Caucasus. Here, for the first time in the history of medicine, he began to operate on the wounded with ether anesthesia. In total, the great surgeon performed about 10,000 operations under ether anesthesia.

Horror stories about anesthesia

No one will ask a traumatologist about gynecological diseases. However, questions about anesthesiology are asked to doctors of any specialty, who, as a rule, understand it no more than other ordinary people - anesthesiology is a very specific subject. Once I came across this: a patient came for tooth extraction under anesthesia, paid for the extraction and anesthesia, but refused the anesthesia, because a relative (therapist) said that EVERYONE dies from anesthesia.

Patients who undergo operations under general anesthesia write with pleasure in various forums how afraid they are of “general anesthesia,” and a chorus of well-wishers echoes them: “yes, yes, anesthesia is like dying a little,” “anesthesia has a lot of contraindications,” “maybe allergic shock!” It seems that you can do without anesthesia and there is no need to monitor the patient’s somatic condition during the most complex and traumatic interventions. At the same time, no one writes that pain has a very, very strong effect on health, that not everything can be tolerated, that a surgeon is a person who only performs an operation, and an anesthesiologist is precisely the specialist who cares for the patient.

Side effects

Nausea is a common side effect of general anesthesia.

There are a number of potential side effects of anesthesia.

Some people may experience none, others several. None of the side effects are particularly long-lasting and usually occur immediately after anesthesia.

Side effects of general anesthesia include:

temporary confusion and memory loss, although this is more common in older people
dizziness
difficulty urinating
bruising or soreness from the IV
nausea and vomiting
trembling and chills
sore throat due to breathing tube

Consequences and side effects

The drug is safer than many of its previously used analogues. However, it also has accompanying actions. Side effects of Propofol include:

arterial hypotension (low blood pressure),
bradycardia (slow heart rate),
depression of respiratory function (up to short-term apnea).

In rare cases, convulsions, allergic reactions may occur, and after waking up - nausea, vomiting, and headache. The vast majority of patients have a completely normal reaction to Propofol.

To minimize side effects, a doctor should prescribe Propofol based on preliminary tests, which should determine how safe the use of this drug is for a particular patient.

In addition, constant monitoring of the patient’s condition under anesthesia and the availability of resuscitation equipment in the clinic, incl. apparatus for artificial ventilation of the lungs.

Propofol can only cause harm if the permissible dosage is exceeded. But provided that the drug is prescribed correctly and the anesthesiologist is equipped with all the means necessary for control, the occurrence of such a situation is excluded.

Risks

In general, general anesthesia is safe. Even very sick patients can be safely anesthetized. The surgical procedure itself involves much greater risk.

Modern general anesthesia is an incredibly safe procedure.

However, older adults and those undergoing lengthy procedures are most at risk for complications . These findings may include postoperative confusion , heart attack, pneumonia, and stroke.

Some specific conditions increase the risk for a patient undergoing general anesthesia, for example:

obstructive sleep apnea, a condition in which people stop breathing while sleeping
seizures
existing heart, kidney or lung disease
high blood pressure
alcoholism
smoking
previous negative reactions to anesthesia
medications that may increase bleeding - aspirin, warfarin , for example
drug allergy
diabetes
obesity or overweight

Unintentional intraoperative awakening

This refers to rare cases where patients report remaining conscious during surgery, long after the anesthetic should have taken effect . Some patients are aware of the procedure itself, and some may even feel pain.

Unintentional intraoperative awakening is incredibly rare, affecting approximately 1 in every 19,000 patients under general anesthesia.

Because of the muscle relaxants used at the same time as anesthesia, patients are unable to let their surgeon or anesthesiologist know that they still know what is happening.

Unintentional intraoperative awakening is more likely during emergency surgery.

Patients who experience unintentional intraoperative awakening may suffer from long-term psychological problems. Most often, awareness is short-lived and only sounds, and occurs before or at the very end of the procedure.

According to a recent large-scale study of this phenomenon, patients experienced involuntary twitching , stabbing pain, pain, paralysis and suffocation, among other sensations.

Because unintentional intraoperative awakening is rare, it is unclear exactly why it occurs.

What to do if numbness of teeth does not go away after anesthesia

Lack of sensitivity can last for quite a long time, especially after the removal of difficult wisdom teeth. Sometimes you have to wait 8 or even 9 hours for “defrosting”.

If all the normal deadlines have passed, and the numbness of the gums, tongue or nose does not go away, you should consult a dentist. It is possible that during the manipulations the nerve that is responsible for the innervation of the mucous membranes of the nose or tongue was damaged.

This happens when extracting figure eights with roots that come close to the mandibular nerve trunk. Fortunately, this situation is very rare, occurring in only 0.5% of patients.

But even if you fall into this half a percent, it is fixable. Over time, the nerve recovers and sensitivity returns. The bad news is that sometimes the recovery process takes several months (but no more than six months), and it is impossible to speed it up.

Types

There are three main types of anesthesia . General anesthesia is just one of them.

Local anesthesia is another option. It is done before minor surgeries such as toenail removal. This reduces pain in small, focused areas of the body, but the person receiving treatment remains conscious.

Regional anesthesia is another type. It numbs the entire part of the body - the lower half, for example, during childbirth. There are two main forms of regional anesthesia: spinal anesthesia and epidural anesthesia.

Spinal anesthesia is used for operations on the lower extremities and abdomen. The anesthetic is injected through a special very thin needle into the intervertebral space of the lumbar region . Epidural anesthesia is used for long-term pain relief. Can be used for operations on the chest, abdomen, and lower extremities. During an epidural, a thin plastic catheter is inserted through which a local anesthetic is injected. Pain relief can last as long as needed.

Science and clinical practice

I will try to tell you about the effect of anesthesia on the human body, and in particular on the brain.

Anesthesia is a state of loss of consciousness that is induced artificially and is characterized by its reversibility. Anesthesia produces pain relief, which allows it to be used in surgery to relieve the patient of the suffering associated with the sensation of physical pain. The state of anesthesia is achieved with the help of anesthetics; there is a certain medical specialization - an anesthesiologist who selects the optimal dose and combination of drugs based on the individual characteristics of the patient’s body, in addition, the type of medical effect matters. It often happens that anesthesia causes fear in people to a large extent more than the surgical operation itself. Among other things, there are many rumors and rumors about anesthesia; some fear that anesthesia can cause death. Is it really? How does anesthesia affect the human body? Is it dangerous, will anesthesia affect further memory problems and cognitive functions of a person?

I don’t want to offend anyone, but very often I hear amazingly illiterate and ignorant statements about anesthesia on this subject, not only from ordinary people, but also from doctors, but almost any non-anesthesiologist will be happy to tell you thoughtfully something like “anesthesia is always anesthesia” or “Anesthesia is not candy.” It’s good that at least the majority do not repeat the generally accepted nonsense that “anesthesia takes 5 years of a person’s life” or “affects the heart.” Patients who undergo operations under general anesthesia write with pleasure in various forums how afraid they are of “general anesthesia,” and a chorus of well-wishers echoes them: “yes, yes, anesthesia is like dying a little,” “anesthesia has a lot of contraindications,” “maybe allergic shock!” It seems that you can do without anesthesia and there is no need to monitor the patient’s somatic condition during the most complex and traumatic interventions. True, no one writes that pain has a very, very strong effect on health, that not everything can be tolerated.

Most of us know about anesthesia that it is used during operations as an anesthetic; this is where our knowledge ends and fears, worries, and speculation begin. General anesthesia, or anesthesia, is a time-limited state of unconsciousness during the administration of special painkillers, during which time the patient undergoes a surgical operation, after which the patient’s consciousness is restored. The actions of the anesthesiologist are aimed at relieving the patient of pain during the operation, as well as to ensure a normal and painless transition to a state of consciousness, with no discomfort.

How general anesthesia affects the human body should be discussed based on what type of anesthesia is used. General anesthesia is divided according to several criteria, but again we will not go deeper, but will only name and characterize the main types used in practice. For major operations on internal organs located above the diaphragm, which separates the chest cavity from the abdominal cavity, anesthesia with artificial ventilation of the lungs is usually used, and, in heart operations, with artificial circulation. Anesthesia drugs can be administered either intravenously or through inhaled air, or both. Sometimes such anesthesia is also supported by spinal (subdural) or epidural anesthesia, which, in turn, can be used independently. During spinal anesthesia, the drug is injected under the dura mater into the fluid that washes the spinal cord at the level of its segments responsible for sensitivity in the surgical area. For the duration of the anesthetic, these segments and all those located below them become insensitive to pain, and the anesthetized parts of the body become immobile. With epidural anesthesia, the drug that causes it is injected above the dura mater, at the level of the nerve trunks extending from the spinal cord and, washing them, causes an interruption of sensory and motor nerve impulses at the site of action of the drug. Organs located below the operation site may not be anesthetized. Both types of such anesthesia are considered gentle: they are the least aggressive and have the advantages of general and local anesthesia, while practically not having their disadvantages. Epidural anesthesia can also be prolonged. In this case, a thin catheter (tube) is placed over the dura mater and brought out. It is glued to the patient’s back and painkillers are added there: this postoperative pain relief is the most effective. These types of anesthesia require a very small amount of a drug from the group of local anesthetics; until recently, pain relief was done with lidocaine, but now drugs have been proposed that act longer and are more effective in smaller doses.

The anesthesiologist chooses the type of anesthesia based on the individual characteristics of the person being operated on; the choice depends on his physical condition, on what kind of operation is being performed, and even the level of qualification of the surgeon and the anesthesiologist himself matters. In order to perform the same operation on different people, different types of anesthesia can be applied to them; the ideal combination of drugs is selected for the patient, which is achieved by mixing different drugs and types of pain relief. Thus, the importance of a specialist anesthesiologist is extremely difficult to overestimate; this doctor is always present during all major operations.

People who have undergone surgery, and therefore general anesthesia, report the following symptoms and unpleasant moments after the use of painkillers:

Firstly, memory impairments are possible, which can manifest themselves in different ways, from subtle isolated cases to regular and pronounced ones that arise suddenly.

Secondly, after using anesthesia, some note sleep disturbances, which can persist even several months after the operation.

Thirdly, immediately after surgery, the use of anesthesia can cause headaches, hallucinations, hearing and speech disorders. All these symptoms, as a rule, disappear within the next few hours after the application of anesthesia.

And this is not a complete list of troubles that can be caused by the use of anesthesia, as people who have suffered it say.

Now let's talk about the effect of general anesthesia on the brain:

Some of the consequences of anesthesia are memory impairment, decreased attention, and deterioration in learning ability. The disorders described above in medicine are called postoperative cognitive dysfunction. Memory impairments observed after anesthesia always cause a lot of trouble for patients. Patients are concerned about what happened to their memory after anesthesia, how long it will last, and what can be done to alleviate the condition. As a rule, anesthesiologists cannot give clear answers to the questions posed above. Memory impairment after anesthesia is not such a rare complication. Most studies regarding post-anesthesia memory impairment have focused on cardiac surgery. It has been shown that during the first week after anesthesia, memory impairment occurs in 30-80% of cardiac surgery patients. Patients who have undergone non-cardiac surgery are at slightly lower risk of developing memory impairment after anesthesia. Thus, in the first week after anesthesia, a decrease in memory and attention is observed in 25% of patients, and after 3 months – in 10% of patients. There are studies that show that after undergoing anesthesia, cognitive disorders can persist for a year or more.

Scientists have not reached a consensus on which type of anesthesia has the least effect on the brain. According to some, disorders of cognitive functions such as memory, attention and learning occur with the same frequency, both with general anesthesia and with regional methods of anesthesia (spinal anesthesia; epidural anesthesia). Others have concluded that regional anesthesia is associated with fewer incidents of memory and attention impairment.

There is no clear answer regarding the harmfulness or harmlessness of individual anesthesia drugs. It is believed that sharp changes in the delivery of oxygen to the brain are important in the development of memory impairment during anesthesia. During anesthesia, it is possible to develop certain conditions that are associated with the development of temporary oxygen starvation of the cerebral cortex. These conditions are associated with a significant drop in blood pressure and a marked decrease in oxygen levels in the blood.

Despite the fact that the causes of post-anesthesia intellectual impairments continue to remain unclear, scientists have found a number of factors that increase the risk of developing attention and memory impairments after anesthesia: older age, repeated anesthesia, long-term surgery, low level of education of the patient, and those that developed after surgery. infectious and respiratory complications.

In order not to scare potential patients, as a neurosurgeon I can say that often all problems with memory and cognitive functions are reversible! There is a sufficient arsenal of tools to solve this issue, which in most cases will help not lead to the development of complications or will help restore lost functions as quickly as possible.

The most important thing I want to say in conclusion is that, of course, the risk of anesthesia and the volume of surgical intervention are always assessed. You always need to make a CHOICE!

The choice is of course yours, but after an explanation from the TEAM (anesthesiologist and surgeon) about the development of possible pros and cons - and the occurrence of possible complications.

By the word TEAM I mean a well-coordinated team (anesthesiologist, surgeon, nurses) who work in one direction - for the benefit of the patient with a good quality of life!

Local vs General

There are a number of reasons why general anesthesia may be chosen over local anesthesia.

This choice depends on age, health and personal preference.

The main reasons for choosing general anesthesia are:

The procedure will likely take a long time.
There is a possibility of significant blood loss.
This may affect breathing, for example during breast surgery.
The procedure will make the patient feel uncomfortable.
It is difficult for the patient to maintain a forced position during surgery.

The purpose of general anesthesia is to induce:

pain relief or elimination of the natural response to pain
amnesia or memory loss
immobility or elimination of motor reflexes
dream
relaxation of skeletal muscles

However, the use of general anesthesia poses a higher risk of complications than local anesthesia. If the surgery is minor, then the patient is offered local anesthesia, especially if he has a condition such as sleep apnea or other risk factors.

After operation

When to get up after surgery? The general rule is as early as possible! Don't linger! But of course, with the doctor's permission. Lying for a long time is fraught with the development of hypostatic pneumonia, acute thrombosis of the veins of the lower extremities, bedsores on the back, sacrum, and heels.

A case is described: a young patient, 23 years old, practically healthy, after a routine uncomplicated appendectomy, lay on his bed and did not want to get up (he was in pain, you see). On the third day I finally got up. Result: pulmonary embolism - instant death.

When can I return to normal work after anesthesia? After general anesthesia, after just two days, a person can perform normal work, work with complex mechanisms that require concentration, and drive a car! But the operating surgeons discharge the patient after 7-8 days, when the stitches are removed and the wound has healed. You can drink after anesthesia when your reflexes are restored and there is no nausea or vomiting.

We also recommend reading: Deep anesthesia: is there a great risk for pregnant women?

You can eat it the next day, the diet is gentle: you can’t eat spicy, salty, fried, canned food, sausages, or alcohol. The Pevzner diet is usually followed.

Preoperative assessment

Before undergoing general anesthesia, patients should undergo a preoperative assessment to determine the most appropriate medications, their amount and combination.

Some of the factors that should be examined in the preoperative assessment include:

body mass index (BMI)
disease history
age
medications taken
time before anesthesia
alcohol or drug use
use of pharmaceuticals
examination of the oral cavity, teeth and respiratory tract
cervical spine mobility study

It is important that you answer these questions accurately. For example, if a history of alcohol or drug use is not mentioned, insufficient anesthesia may be given, which could lead to dangerously high blood pressure or unintentional intraoperative awakening.

Anesthesia during pregnancy

Typically, dentists recommend treating teeth and gums while planning pregnancy, because anesthetics can indirectly affect the intrauterine development of the fetus. However, if necessary, it is better to go to the doctor in the second trimester of pregnancy, but if there is an urgent need for treatment, then it can be performed at any stage.

The most modern painkillers, which do not contain adrenaline, are used for pregnant women to avoid the possibility of increased blood pressure and contractions of the uterus. Usually, drugs with minimal toxic effects on the body are also used.

In some cases, pregnant women are transferred to a hospital for treatment.

Thus, all necessary procedures can be carried out under the strict supervision of the attending physician to avoid any complications.

Stages

The Gödel classification, developed by Arthur Ernest Gödel in 1937, describes four stages of anesthesia. Modern anesthetics and updated methods of drug have improved the speed of onset of anesthesia , overall safety and recovery, but the four stages remain essentially the same:

General anesthesia is similar to a comatose state and different from sleep.

Stage 1 or induction . This phase occurs between the administration of the drug and loss of consciousness. The patient moves from analgesia without amnesia to analgesia with amnesia.

Stage 2, or arousal stage . The period after loss of consciousness, characterized by agitated and delirious activity. Breathing and heart rate become erratic, and nausea, dilated pupils, and holding your breath may occur.

Due to irregular breathing and the risk of vomiting, there is a danger of suffocation. Modern fast-acting drugs are aimed at limiting the time spent on the 2nd stage of anesthesia.

Stage 3 or surgical anesthesia : muscles relax, vomiting stops, breathing is suppressed. Eye movements slow and then stop. The patient is ready for surgery

Stage 4, or overdose : if too much anesthetic has been administered, then depression of the brain stem occurs . This leads to respiratory and cardiovascular collapse.

The anesthesiologist's priority is to get the patient to stage 3 anesthesia as quickly as possible and keep him there throughout the operation.

How do you wake up after anesthesia?

The stage of recovery from general anesthesia after surgery is considered very important and requires the anesthesiologist to fully focus on the patient’s condition. Recovery from anesthesia begins the moment the anesthetic supply stops. Consciousness and sensitivity begin to return to the patient: first, muscle tone and reflex muscle reactions return, and the nervous system is excited, which can manifest itself as incoherent speech and motor restlessness. After this, consciousness slowly returns and the patient wakes up - in the first minutes he is disoriented in space, lethargic, inhibited, speech and expression of emotions are difficult.

At the awakening stage, the anesthesiologist performs a series of tests that allow you to correctly assess the restoration of respiratory function. Only after a positive result is the patient extubated and given permission to be transported to the ward.

In most cases, after surgery, the patient is transported to the ward of his department, where he was before surgery. The exception is those situations when the patient is in serious condition - in this case he is transferred to the intensive care unit.

Transporting the patient after surgery