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.
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.
Trial and error
Although general anesthesia (anesthesia) has been used in medicine since the mid-19th century, for many decades this field was purely practical, that is, based on trial and error. Anesthesiology as a science began to take shape only in the middle of the 20th century. Just half a century ago, in the USSR, anesthesiologists were not trained professionally. In those distant times, the administration of anesthesia was most often entrusted to surgeons - as a rule, those losers who were of little use in the operating room. But if a person was not able to learn to hold a scalpel well in his hands, then it was difficult to expect ideal work from him in other areas of medicine. Therefore, indeed, various complications during anesthesia (even death) were quite common in those days. And the quality of the drugs for general anesthesia and equipment used in the distant past, frankly speaking, left much to be desired.
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
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.
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.
Anesthesiology in dentistry
And a little more about outpatient anesthesiology and anesthesiology in dentistry, in particular. It is anesthesia (central anesthesia) that is used extremely rarely in modern outpatient dentistry and this is, as a rule, unjustified - like shooting sparrows from a cannon. The optimal option at the moment is to carry out sedation with simultaneous monitoring of the patient’s condition - monitoring. This enhances local anesthesia and reduces the amount of anesthetic required to achieve the effect. There are no contraindications to this method for people who have walked to the dentist’s office. According to his own feelings, the patient sleeps in the same way as during anesthesia, but wakes up quickly, is oriented and is able to move around on his own.
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.
Is it possible to die from anesthesia?
The mortality rate from sedation does not exist, and from anesthesia it is so low that the mortality rate from local anesthesia exceeds it. Addiction to drugs and alcohol is not a contraindication for dental treatment under sedation, although it complicates the anesthesiologist’s task. And, finally, another professional saying: “It’s not the anesthesia that’s scary, it’s the anesthetizer that’s scary.” And an incompetent person giving advice.
Author: anesthesiologist-resuscitator Kokhan Arkady Mironovich
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.
Features of pain relief in pregnant women
One of the most common misconceptions is that pregnant women are contraindicated for dental treatment. You should not trust unreliable sources; dentistry and pregnancy are completely compatible concepts. Expectant mothers should undergo a professional examination during planning and at 8, 18 and 28 weeks of pregnancy. Untreated infections in the oral cavity contribute to the development of other dangerous diseases.
The question immediately arises: can the use of dental anesthesia harm the health of the unborn child? Modern technologies allow the use of drugs with lower concentrations of adrenaline. Accepted painkillers are ultracaine, primacaine or mepivacaine*. They do not penetrate the placenta, therefore, do not harm the body of a pregnant woman.
*A verified and accurate list of acceptable medications can be obtained from your doctor.
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 often can sedation be used?
During sedation, all the patient’s reflexes (cough, gag) are preserved, verbal contact is preserved: the doctor may ask you to follow simple commands like “open your mouth wider.” Sedation can be done as many times as you like. Every other day and every day. The drugs used to achieve sedation (no narcotic drugs are used) are eliminated from the body very quickly - within a few minutes. The anesthesiologist constantly adds them during the sedation process. A few minutes before the end of the operation, the administration of sedatives is stopped, and the patient wakes up on his own.
