Types of anesthesia
By the method of administering drugs for anesthesia, anesthesia is inhaled and non-inhalation. In inhalation anesthesia, narcotic drugs are administered by inhalation through an intubation tube inserted into the patient's airways. Non-induction anesthesia involves the administration of drugs intravenously, rectally.
In the depth of the narcotic sleep, the anesthesia is superficial and deep.
The anesthesia is also clear, it is anesthesia, in which only one narcotic substance is administered.
Mixed anesthesia is when a mixture of different drugs is injected. With combined anesthesia, a combination of different drugs and the way they enter the body are used.
Narcotic drugs in the human body cause specific changes in all organs and systems.
When the concentration of narcotic substances reaches a certain level in the patient's blood, depression of consciousness, circulation, and breathing occurs. These changes occur with a certain sequence, which determine the depth of narcotic sleep. Therefore, during the narcotic sleep, certain stages are isolated.
The first stage is called the analgesia stage. The stage is characterized by the fact that the patient is conscious, but his inhibition is noted, the patient is drowsy, responds in monosyllables, the pain sensitivity decreases somewhat. The pupils' reaction to light remains, all vital signs( blood pressure, pulse, respiration) remain unchanged. This stage is also called raush anesthesia; this anesthesia is used for small surgical operations( opening of abscesses, removal of the nail plate), or for painful manipulations( dressings), invasive methods of research. The duration of the stage is 3-4 minutes.
The second stage is called the excitation stage. The stage is characterized by inhibition of the centers of the cerebral cortex, while the subcortical centers are in excitation. During this stage, the patient has no consciousness, psychomotor agitation is observed, the patient cries, curses, waved his arms, kicks, can try to get up from the operating table, escape, so these patients need to be fixed. In patients, there is hyperemia of the skin, increased blood pressure, tachycardia, hypertonic muscle, increased reflexes, increased respiration. Pupils are dilated, but they react to light, perhaps lachrymation. Cough, increased bronchial secretion, vomiting can also be observed. Patients suffering from alcoholism in the anamnesis, in the stage of excitation, behave more violently. In this stage, surgical interventions are not carried out. The duration of the stage is 7-8 minutes.
The third stage is called surgical, at this stage, surgical operations are performed. In most cases, the third stage begins in 20 minutes. Most often, the patient behaves calmly, all vital signs( breathing, palpitation, blood pressure) reach normal values. In the surgical stage, four levels are distinguished.
The first level is characterized by complete lack of consciousness, pain and tactile sensitivity. The patient is calm, the blood pressure numbers and heart rate are close to normal. There is a narrowing of pupils of the patient, however their reaction to light remains. At this stage there is a decrease in the motor activity of eyeballs. Corneal and pharyngeal reflexes do not change. Muscle tone is preserved, therefore cavitary operations are not performed.
At the second level, eyeballs do not move, pupils dilate, reaction to light decreases. Corneal and pharyngeal reflexes by the end of the second level completely disappear. The parameters of respiration and blood pressure are normal. The tonus of muscles decreases, therefore at this level it is possible to perform cavitary operations.
The third level is the level of deep anesthesia. During this level, the decrease in the numbers of blood pressure is fixed, the pulse becomes faster, the filling becomes small, bradypnoe is noted, the respiration is superficial, the pupils are dilated, the light does not react, and the disappearance of the corneal reflex is noted. Skeletal muscles are completely relaxed. With the relaxation of the muscles of the lower jaw, it can hang, this leads to tongue lagging and stopping breathing. To prevent this complication, it is necessary to bring the jaw into a "dog bite", i.e. To bring it forward, the introduction of an air duct is also applied.
Achieving the fourth level is life-threatening and can lead to the death of the patient. At this level, first of all, pupils dilate, blunt reaction to light, dryness of the cornea( lack of characteristic luster).There is a change in breathing, it becomes superficial, since paralysis of the intercostal muscles occurs and breathing is performed only by narrowing and widening the diaphragm. Tachypnea is noted, but the pulse is threadlike, hypotension, sometimes blood pressure may not be determined at all.
The fourth stage is the stage of awakening. At this stage, the concentration of the drug in the patient's blood decreases, and all the symptoms of anesthesia disappear in the reverse order.
Before anesthesia the patient should be examined and trained by an anesthesiologist. Upon examination, the doctor collects information about the underlying disease, about which the operative intervention will be performed, and about the concomitant diseases. The anesthesiologist should find out from the patient the presence of allergic reactions to drugs, to find out the mental state of the patient, to know whether he endured before surgery and anesthesia. Anesthesiologist to select a specific patient anesthesia method, you must define the shape of the face, the chest of the patient cells, expression of subcutaneous adipose tissue, especially the structure of its neck. Before the operation, preparation of the gastrointestinal tract is necessarily carried out, for this purpose a cleansing enema is made, if necessary, the stomach is washed.
To carry out anesthesia, medicament preparation of the patient or premedication is used. Premedication should be performed on the day before the operation and on the day of surgery to reduce the psychoemotional reaction and neutralize the function of the vagus nerve. To carry out the day before the surgery premedication used hypnotics( donormil, noksiron, Phenazepamum), analgesics( Promedolum) antigistamnnnye and neuroplegic agents( chlorpromazine, suprasgin, diphenhydramine), analeptic( Neostigmine, kordiamin), tranquilizers( seduksen, Relanium).For sedation carried out on the day of surgery used neuroplegic drugs, antihistamines, analgesics, for suppressing vagus nerve and to reduce salivation atropine. The introduction of all these drugs is prescribed by an anesthesiologist. The nurse must accurately fulfill the doctor's prescription and administer the medication over time. If the patient changes his condition during the training, the nurse must immediately notify the doctor. Before the operation, it is necessary to examine the oral cavity and, if dentures are available, they are removed.