Today you will not surprise anyone with such a treatment method as surgery. But a few centuries ago, the operation was equated with death: most patients died from pain shock or sepsis. For a long time, the introduction of a person into a surgical sleep remained the most difficult task of medicine. With the study of chemistry, the process went faster. More perfect mixtures and preparations for anesthesia were created, which, in addition, are now carried out in different ways. One of them is endotracheal anesthesia. What it is? How is it used and when is it needed? We will answer these and many other questions in the article.
From the history of endotracheal anesthesia
For the first time this type of anesthesia was tried in the XIV-XV centuries, when the doctor Paracelsus from Switzerland inserted a tube into the human trachea, which saved his life. Three centuries later, people were saved in this way from lack of air. In 1942, an anesthesiologist from Canada first used muscle relaxants - substances that reduce the tone of skeletal muscles up to complete immobilization. Thanks to this discovery, anesthesia became safer and more perfect, allowingspecialists to fully control the course of surgical sleep during the operation.
In the middle of the 20th century, endotracheal anesthesia began to develop rapidly, which was facilitated by Soviet doctors. Today it is the most common method of general anesthesia used in most operations.
Endotracheal anesthesia: what is it?
In order to protect the body from the enormous stress of surgery, anesthesia is used. It can be local, regional or general. The latter type is called anesthesia. It is characterized by complete "turning off" of the patient's consciousness with the onset of surgical sleep. In modern anesthesiology, intravenous, mask or combined anesthesia is used. The latter combines two methods: substances enter both the blood and the respiratory tract. This type is called endotracheal anesthesia.
Experts rightfully consider it the safest and most effective method of pain relief: it allows you to fully control the patient's condition, achieve deep surgical sleep and relaxation of skeletal muscles, as well as avoid such unpleasant complications as aspiration and respiratory failure.
Indications
Endotracheal anesthesia protects the patient from pain shock and respiratory failure, which allows it to be used during operations and resuscitation. Indications for combined anesthesia may include:
- operations on the mediastinum, pharynx, inner ear, oral cavity andhead;
- interventions requiring the use of muscle relaxants;
- faults in the nervous system;
- full stomach syndrome;
- risk of airway obstruction.
Endotracheal general anesthesia is more commonly used for long operations that last more than 30 minutes. It can be used at any age for different patient conditions, because it does not burden the heart and is much less toxic than other methods of pain relief.
Contraindications
Elective surgical treatment (for example, surgery to remove a mediastinal tumor) is accompanied by a thorough study of the patient's condition. The doctor has the necessary time to familiarize himself with the patient's medical record, having time to calculate the possible risks and identify contraindications to a particular method of anesthesia. Combined anesthesia is not recommended for the following conditions:
- infectious diseases;
- pathology of the liver, kidneys;
- suspected myocardial infarction;
- respiratory pathology;
- physiological features of the structure of the pharynx;
- severe endocrine disorders.
The use of endotracheal anesthesia for upper respiratory tract infections is especially dangerous, since the risk of infection of the lungs is high.
Stages of combined anesthesia
So, endotracheal anesthesia. What is it for a doctor? The anesthesiologist performs three consecutive steps: introduction to surgical sleep, maintenance of a stable state, and awakening. The first stage consists inlight induction anesthesia. The patient receives drugs intravenously or inhales a mixture of gases. When the muscles are completely relaxed, the anesthesiologist inserts an endotracheal tube into the lumen of the trachea. It provides ventilation of the lungs with oxygen and inhalation of gaseous anesthetics.
After the surgeons have finished their work, the crucial moment for the anesthesiologist comes - the withdrawal of the patient from anesthesia. The dosage of drugs is gradually reduced. After restoration of spontaneous breathing, extubation is performed - removal of the endotracheal tube from the trachea. The patient is transferred to the intensive care unit, where vital signs and postoperative recovery are monitored.
Introductory anesthesia
Light initial anesthesia is necessary for painless and safe intubation, without which endotracheal anesthesia is impossible. To achieve this state, inhalation or intravenous painkillers are used. In the first case, the patient breathes through the mask vapors of "Etran", "Foran", "Ftorotana" or other similar mixtures of anesthetics. Sometimes nitrous oxide with oxygen is sufficient.
Barbiturates and neuroleptics (droperidol, fentanyl) are commonly used as intravenous drugs. They are used in the form of a solution (no more than 1%). The dose of the drug is selected by the anesthesiologist individually for each patient.
After light anesthesia has taken effect, tracheal intubation is performed. ForMuscle relaxants are used to relax the neck muscles. The tube is inserted using a laryngoscope, after which the patient is transferred to artificial ventilation. The stage of deep anesthesia begins.
Droperidol instructions
Droperidol is an antipsychotic often used in endotracheal anesthesia. According to the chemical structure, this substance is a tertiary amine. It has a sedative effect within 3 minutes after administration. Blocks dopamine receptors, which causes neurovegetative inhibition. In addition, it has antiemetic and hypothermic effects. Breathing is slightly affected.
Prescribed for premedication, induction anesthesia, myocardial infarction, shock, severe angina, pulmonary edema and hypertensive crisis. Recommended as a drug that eliminates nausea and vomiting. It has low toxicity, which allows its use in pediatric surgery and obstetrics.
Method of using antipsychotics during induction anesthesia
There are several options for performing neuroleptanalgesia. Induction anesthesia is usually carried out according to the following scheme: droperidol, the instruction of which was discussed above, in an amount of 2-5 ml with 6-14 ml of fentanyl is administered intravenously to the patient. Simultaneously served mask with a mixture of nitrous oxide and oxygen in a ratio of 2:1 or 3:1. After depression of consciousness, muscle relaxants are injected and intubation begins.
Droperidol has an antipsychotic effect within 4-5 hours, so it is administered at the beginning of anesthesia. It is calculated taking into accountbody weight: 0.25-0.5 mg/kg. Re-injection of the drug is necessary only for long-term operations.
Fentanyl in the amount of 0.1 mg is administered every 20 minutes and its supply is stopped 30-40 minutes before the end of the surgical intervention. The initial dose is 5-7 mcg/kg.
Intubation
After depression of consciousness, artificial ventilation of the lungs with oxygen is carried out using an anesthetic mask. After that, the doctor performs intubation through the mouth (less often through the nose). The head is thrown back, the mouth is opened. A laryngoscope with a straight blade is inserted along the midline between the palate and the tongue, pressing the latter upwards. Advancing the tool further, lift the top of the epiglottis. The glottis is shown, into which an endotracheal tube is inserted. It should go into the trachea by about 2-3 cm. After successful intubation, the tube is fixed and the patient is connected to a ventilator.
Less commonly used is a laryngoscope with a curved blade. It is inserted between the base of the epiglottis and the root of the tongue, pushing the latter upward away from itself. If it is impossible to insert the tube through the mouth, use the lower nasal passage. So, for example, an operation is performed to remove a cyst in the oral cavity.
Maintenance and recovery from anesthesia
After intubation and connecting the patient to the ventilator, the main period begins. Surgeons are actively working, the anesthesiologist is closely monitoring life support indicators. Every 15 minutes they check the heart rate, blood pressure, monitor the patient's cardiac activity with the help of monitors.
General anesthesia is maintained withadditional doses of antipsychotics, muscle relaxants or inhalation with mixtures of anesthetics. Operation under combined anesthesia allows the anesthesiologist to adapt to the needs of the body in pain relief, ensuring an optimal level of safety.
After the end of the surgical manipulations, the last stage comes - the exit from the narcotic sleep. Until this moment, the dosage of the drugs is gradually reduced. To restore breathing, atropine and prozerin are administered with an interval of 5 minutes. After making sure that the patient is able to breathe on his own, extubation is performed. To do this, clear the area of the tracheobronchial tree. After removing the tube, a similar procedure is performed with the oral cavity.
Post-op care
After leaving the operating room, the patient is placed in the intensive care unit, where his condition is carefully monitored. After general anesthesia, discomfort develops, less often complications. Usually postoperative patients complain about:
- pain;
- discomfort in the throat;
- nausea;
- weakness and muscle fatigue;
- drowsy;
- confusion;
- chill;
- thirst and lack of appetite.
These symptoms usually resolve within the first 2-48 hours after surgery. To eliminate pain, analgesics are prescribed.
So let's recap. Endotracheal anesthesia - what is it? This is a method of introducing a person into a surgicalsleep, which allows you to perform complex operations, controlling the activity of the respiratory system. Combined anesthesia is less toxic, and the depth of anesthesia is easily controlled throughout the entire intervention period. Under endotracheal anesthesia, first of all, intubation is meant, followed by connecting the patient to a ventilator. In this case, both inhalation and drug anesthetics are used, which are usually combined.
