"Anesthetic drugs“Ethanol. Hypnotics.

Synaptic education at various levels of the central nervous system and various morphological and functional organization to vary in sensitivity to anesthetic drugs. For example, activating the synapses of the reticular formation of the brain stem in particular are highly sensitive to anesthetic drugs, whereas synapses centers of the medulla oblongata most resistant to it. Differences in sensitivity-telnosti synapses of different levels of the central nervous system explains the presence of certain stages in the action of narcosis.Allocate the following stages:

I - stage analgesia ';II - the stage of initiation;III- stage of surgical anesthesia:

              Level 1 (III1) -poverhnostny anesthesia,              2nd level (III2) -easy anesthesia,              3rd level (III3) - deep anesthesia,              Level 4 (III4) - ultra-deep anesthesia;

IV- agonal stage.

This sequence of stages of anesthesia is valid only as a general scheme, since the excitation step in the application of a number of drugs can be practically absent, the severity varies stage analgesia, and so on. D .. A more detailed description of the individual stages of anesthesia is given with respect to the ether.Tools for anesthesia belong to different classes of chemical compounds. Identify common patterns between their chemical structure and drug activity failed. Established a private individual depending series of compounds (hydrocarbons, barbiturates).From the point of view of practical application tools for anesthesia sub-divided into the following groups.

I. Means for inhalation anesthesiaLiquid volatilesEther for anesthesia Halothanegaseous substancesNitrogen oxide cyclopropaneII. Means for not and not inhalation anesthesiaPropanidid Sodium hydroxybutyrateThiopental sodium Ketamine

By means of anesthesia impose certain requirements. Thus, anesthesia using them should advance quickly as possible and without the stage of initiation. There must be sufficient depth of anesthesia, been ensured and provides optimal conditions for the operation. The important point yaalyaetsya good handling depth of anesthesia during the use of narcosis. Side effects should be absent or minimal. It is desirable that the output from anesthesia was rapid, with no aftereffects. This facilitates after anesthetic period.

The essential characteristic of anesthetic drugs is drug latitude - between the concentration range in which the drug causes anesthesia, and its minimum toxic concentration at which inhibition occurs vital centers of the medulla oblongata. About Drug latitude means for inhalation anesthesia is judged by their concentration in the inhaled air, and means for non-inhalation anesthesia - by the initial dose. Naturally, the more drug latitude, the safety of the drug.It is desirable that the use of narcosis was technically quite simple. One of the requirements is the safety of drugs in relation to fire: they do not need to burn and explode. Currently, it deserves special attention, since there is a large number of operating various equipment, the slightest fault which can cause ignition of flammable anesthetic drugs. When introducing into medical practice new drugs should take into account their cost. Synthesis of the drug must be affordable for its release on an industrial scale.

Means for inhalation anesthesia

For inhalation anesthesia used volatile liquids (ether anesthesia, Halothane et al.), Easily passing into the vapor state, as well as blowing agents (nitrous oxide, cyclopropane). Typically use special anesthetic machines, allowing to create in Wda-Hai air necessary concentration of substances.By inhalation means for inhalation anesthesia they received by diffusion from the lungs into the blood. The absorption of the drug depends on its concentration in inhaled air volume and respiratory rate, and permeability of the alveolar surface, solubility agents for anesthesia and the rate of blood flow in the pulmonary circulation. All this determines the rate of increase of the concentration of drug in the blood and tissues, which determines the speed of development of anesthesia.Most of the inhalational anesthetic agents in the body is distributed more or less uniformly. Some of the differences are related to uneven circulation of organs and tissues. These substances are allocated light, mostly unchanged. Elimination rate is dependent on the same factors as absorption. Especially quickly allocated funds for gaseous anesthesia.

LIQUID volatilesThis group includes ether anesthesia, Halothane.Ether for anesthesia in chemical structure is diethyl ether. It has potent drug activity, drug sufficient latitude, relatively low toxicity. Ether anesthesia is fairly easy to manage, but not as good as the anesthesia caused ftorotanom or cyclopropane.Ester concentration in inhaled air, depending on the method and sensitivity of the patient narkotizirovaniya usually varies from 2-4 to 10-12 vol.%.When using ether anesthesia stage clearly expressed. Stage analgesia characterized by the suppression of pain sensitivity. This is due, apparently, to the oppression of interneuronal transfer of excitation in afferent pathways and decreased functional activity of neurons in the cerebral cortex. Consciousness is thus maintained, but the orientation is broken. Typical amnesia

For ether anesthesia characterized by prolonged excitation stage (10-20 min). This greatly complicates the administration of anesthesia. Stage of excitation is due to increased activity of subcortical structures (mainly the midbrain). This is due to inhibition of the cerebral cortex and off subordinate mechanisms controlling the state of the underlying centers. Consciousness is lost. There is a motor and verbal stimulation. The pupils are dilated. Breathing usually becomes more frequent. Marked tachycardia. Blood pressure fluctuates. Spinal reflexes may increase. In connection with the irritating ether may occur cough, hypersecretion of bronchial and salivary glands, and in contact with the saliva of ether into the stomach - vomiting. It is also possible reflex (with upper respiratory tract) decrease in breathing and heart rate until the apnea and cardiac arrest. These effects are cautioned atropine.

Under surgical anesthesia is further depression transmission as interneurons in the brain and the spinal cord level. Consciousness is turned off. Pain sensitivity is absent. Reflex activity is suppressed. Autonomic reflexes are depressed at the same time not completely. Pupils are narrowed. In stage III, heart rate slows (compared with stage II), blood pressure stabilized, breathing becomes regular. With the deepening of anesthesia heart rate changes, possible cardiac arrhythmias, blood pressure may be reduced. Breathing gradually suppressed. Celebrate good relaxation of skeletal muscles, which facilitates the operation. Muscle relaxation is associated not only with the effect of ether on the central mechanisms of regulation of muscle tone, but with some dampening effect on its neuromuscular synapses. It should also be borne in mind that the air strengthen and prolong the blocking effect on neuromuscular transmission antidepolyarizuyuschih curariform funds.

In applying the activated ester central links sympathoadrenal system, which results in the release of epinephrine from the adrenal glands. Myocardial function and liver are generally not affected. Rarely jaundice quickly passing. Renal function is inhibited. Can albuminuria. If acidosis develops deep anesthesia (in blood ketone bodies accumulate).

Awakening from anesthesia with ether, the light which is released in an unmodified form, occurs gradually (about 30 min).

However, to fully restore the functions of the brain takes a few hours. Long-term remains analgesia. In poslenarkoznom period is often a vomiting. Irritability broadcast on airway mucosa may be the cause of postoperative bronchopneumonia.

If overdose occurs agonal stage, due to a sharp inhibition of the respiratory and vasomotor centers of the medulla oblongata. Volume and respiratory rate decreases progressively and develops asphyxia. Heart failure occurs, the blood pressure drops. Pupils in the agonal stage dramatically expanded. If you do not take appropriate measures, the patient dies from respiratory paralysis, to the center and the subsequent cardiac arrest.

An important role in determining the stage of anesthesia plays electroencephalography (EEG). When using ether in stages I and II anesthesia observed desynchronization biopotential. Frequent low-amplitude oscillations are recorded. Under surgical anesthesia EEG synchronization occurs: there are high-amplitude oscillations whose frequency decreases with depth of anesthesia. In the agonal phase wave amplitude decreases sharply until the complete disappearance of the bioelectric activity.

Similar EEG changes characteristic of most anesthetic drugs. However, keep in mind that for each drug are typical features of their dynamics of EEG in different stages of anesthesia.

Relatively common in anesthesiology received Halothane (halothane, fluotan). Halothane relates to a fluorine-containing aliphatic compounds. Characterized by high drug activity (3-4 times greater than air). Anesthesia is rapid (3-5 min) with a very short step excitation. Introduction of anesthesia ftorotanom performed at 4 vol.% (In the inhaled air). To maintain sufficient anesthesia ingalya¬tsii 0.5-2.5 vol.% Halothane. Anesthesia ftorotanom manageable. Upon termination of inhalation drug the patient wakes up after 5-10 minutes. Drug considerable latitude halothane (similar to that of ether).

Anesthesia proceeds with satisfactory muscle-relaxing tion. Halothane mioparalitichesky enhances the effect of anti-depolarizing curariform funds, but to a lesser extent than the air.

For action halothane is aetiology associated with high vagal tone (prevented by administering atropine). Halothane reduces blood pressure. This occurs as a result of the oppression of the vasomotor center and sympathetic ganglia (Halothane markedly enhances the action ganglioblokiruyuschih substances), as well as direct myotropic effect on blood vessels. In the application of halothane possible heart aritmii.Obuslovleny they direct influence of halothane on the myocardium, including its sensitization to adrenaline. In this regard, the background ftorotanovogo anesthesia administration of epinephrine, norepinephrine, and ephedrine is contraindicated. If there is a need for pressor substances, it should be administered α-adrenoceptor agonists (phenylephrine). Halothane inhibits the secretory activity of the salivary, bronchial, gastric glands. Halothane liver function, according to available data, violates no more frequently than other means of anesthesia. Irritant properties has not. Acidosis causes. Nausea and vomiting in poslenarkoznom period are rare.

In the body part of halothane significant (approximately 20%) Biotransformation.

Enflurane (ETRAN) - hydrofluorocarbon. A volatile liquid. Has a high drug activity. Anesthesia quickly comes and goes quickly after cessation of inhalation of enflurane. Typical expression miorelak-sation. During the anesthesia used about 3 vol.% Enflurane. Of adverse effects may be marked respiratory depression and a depressing effect on the myocardium. Furthermore, enflurane sensitizes the myocardium to act catecholamines, which could be the cause ofcardiac arrhythmias. Adverse effect on the liver and kidneys were observed. In the body are metabolized to a lesser extent (5-10%).By hydrofluorocarbon is also methoxyflurane (pentran). Has a high drug and analgesic activity. Anesthesia occurs at muscle relaxation. Characteristically slow development of anesthesia (within 10-15 min). Output from anesthetics also occurs gradually (15-30 min). After anesthesia, analgesia persists for a long time. However, methoxyflurane often causes renal dysfunction (there is a condition such as diabetes insipidus with polyuria and dehydration in the body retained urea, creatinine). Often kidney disease is persistent and pronounced. In connection with the use of methoxyflurane nephrotoxicity dramatically reduced, and in some countries discontinued.Halothane, enflurane and methoxyflurane unlike ether fireproof safe.gaseous substances

Ketamine (ketalar, Kalipsol) -poroshkoobraznoe substance pri¬menyaetsya as solutions for intravenous and intramuscular administration. Ketamine is a general anesthetic and a light hypnotic effect of the loss of consciousness (state type neuroleptanalgesia). Surgical anesthesia under the influence of ketamine does not develop. A similar effect of ketamine is sometimes termed "dissociative anesthesia". It is understood that such agents as ketamine, inhibit formation of some central nervous system, and do not affect the other, ie. E. There is a certain effect in their dissociation. When intravenously effect after 30-60 seconds and lasts 5-10 minutes and intramuscular administration - after 2-6 minutes and lasts for 15-30 minutes. Ketamine is inactivated in the liver.Skeletal muscle on the background of ketamine did not relax; may experience involuntary movements of the extremities. Pharyngeal, laryngeal, kaschlevoy reflexes saved. Blood pressure increases, the heart rate increases. Hypersalivation may occur. Slightly increased intraocular pressure.In the postoperative period are not uncommon (especially in adults) are bright, but often unpleasant dreams, psychomotor reactions, hallucinations.Applied ketamine for induction of anesthesia, as well as during transient painful manipulations (e.g., in the treatment of burn surface, etc.. P.).

Combined use of anesthetic drugsIn modern anesthesia is rarely limited to the introduction of a means of anesthesia. Typically combine two or three drugs. Combine means for inhalation anesthesia with inhalation or neingalyatsionnyh formulation.The expediency of such combinations is that it eliminates the stage of excitement and made a quick introduction to anesthesia. For example, anesthesia often start with intravenous tiopen-tal-sodium propanidid providing very rapid development stage of excitation without anesthesia. Especially shown combination with means for neingalyatsionnyh anesthesia drugs with severe stage of excitation (eg, ether). For the same reason the air is combined with nitrous oxide and ftorotanom.The advantage of the combined anesthetic is also that the concentration (dose) of the blend components is less than using a single agent for narcosis, therefore possible to reduce the toxicity and to reduce the incidence of side effects. So, in order to reduce cardiotropic action cyclopropane it can be used in conjunction with nitrous oxide and other drugs.One of the most commonly used at present combinations of narcosis is the following: a barbiturate or other fast-acting drug for non-inhalation anesthetic Halothane + + nitrous oxide.Regardless of the nature of the combinations is important that the main stages of the operation carried out on the background of well-managed products (gaseous means of anesthesia, as well as Halothane, ether).

Ethyl alcohol is a typical substance narcotic type of action. He has a general depressant effect on the central nervous system. In addition, ethyl alcohol has a strong antiseptic properties. For medical practices ethyl alcohol is of limited interest. It is used mainly as an antiseptic. Much greater attention is drawn to the ethyl alcohol with ¬ social dimension, as in connection with the use of alcoholic beverages, he is often the cause of acute and chronic poisoning. Ingestion ethyl alcohol is rapidly absorbed mainly in the small intestine and about 20% - in the stomach.

The absorption rate depends largely on the nature of the contents of the gastrointestinal tract motility and intensity. Particularly rapid resorptive effect of ethyl alcohol comes in the fasting state. Fats and carbohydrates significantly delay its absorption. In the body, 90% of the injected ethyl alcohol is metabolized to SOG and water. The oxidation is accompanied by liberation of ethyl ¬ tion considerable amount of energy (7.1 kcal / g). This occurs in the liver by approximately 10 ml / h Prolonged use of ethyl alcohol can be observed induction of liver enzymes in which the rate of inactivation of ethyl alcohol increased.

Unchanged ethyl alcohol stands lungs, kidneys and sweat glands ¬ mi. Resorptive effect of ethyl alcohol is directed mainly to the central nervous system. It exerts a dampening effect, which increases with the concentration of ethyl alcohol in the blood and tissues of the brain. This is manifested in three major steps: 1) excitation step 2) under anesthesia 3) atonal step.

Stage of excitation is the result of the oppression of brake mechanisms of the brain. It is usually well marked and long-lasting. There is euphoria, increased mood, he becomes overly sociable, talkative. Psychomotor reaction at this violated dramatically affected human behavior, self-control, adequate assessment of the environment, efficiency is reduced. With an increase in the blood concentration of ethyl alcohol come analgesia, drowsiness, then breaks out. Inhibited spinal reflexes. The stage of anesthesia, which, however, neprodolzhi ¬ tional and soon becomes atonal stage. A small drug ¬ cal latitude and expressed excitement stage not allow the use of ethyl alcohol as a means of anesthesia.

One of the manifestations of the central action of ethyl alcohol - its effect on thermoregulation, manifested by increased heat loss (due to vasodilatation of the skin, which is a consequence of the inhibition of the vasomotor center). As a result, the cold ethyl alcohol contributes to hypothermia, and does not preclude it, as is often said. The subjective feeling of warmth after receiving ethyl alcohol associated with the expansion of the cutaneous vessels, is not accompanied by a general increase in body temperature. In this regard, in order to create a feeling of warmth, acceptance of ethyl alcohol can be justified only after getting in from the cold into a warm room, when the danger of frost is excluded.

The diuretic action of ethyl alcohol also has a central origin (reduced production of antidiuretic hormone of the posterior pituitary). Ethyl alcohol has a pronounced effect on the digestive system. Thus, it enhances the secretory activity of the salivary and gastric glands ¬. This is the result of his Llyaetsya psychogenic, reflex, as well as direct action on the gland. Increased secretion of gastric glands under direct ethyl alcohol on the mucosa is obviously due to the release of humoral substances (gastrin, histamine). It should be borne in mind that ethyl alcohol increases the secretion of acid hloristovo ¬ stout.

Pepsin activity at low concentrations (10%) ethyl alcohol is not changed, and decreases with increasing concentration. Since about 20% concentration, ethyl alcohol not only inhibits the secretion of hydrochloric acid, but also food ¬ provisional activity of gastric juice, which is particularly pronounced when receiving alcoholic beverages with 40% and above. In response to stimuli ¬ tal effect on the mucous membrane of high concentrations of ethyl alcohol gastric glands produce large amounts of mucus. It coats the surface of the stomach, and also reduces the concentration of ethyl alcohol.

Changes and motility of the stomach. Ethyl alcohol in sufficient ¬ sufficiently high concentrations cause spasm of the pylorus and reduced gastric motility. On bowel function ethyl alcohol has little effect. Obviously, this is because it is diluted in the stomach and enters the intestine gradually. In medical practice resorptive effect of ethyl alcohol is rarely used. Sometimes it is used as a means protivoshokovoe (given its analgesic effect), rarely - as a hypnotic or sedative substances. In some cases, shows the assignment of ethyl alcohol (in low concentrations) depleted patients

In this case refers to its energy value. However, it should be noted that ethyl alcohol is not a nutrient substance ¬ tion. It does not provide a plastics material for forming fabrics are not deposited and has significant toxicity. With prolonged use of ethyl alcohol develop ¬ tion got used to it and drug abuse (physical and mental).

Reception alcohol can lead to acute poisoning, the degree of which depends on the concentration of ethyl alcohol in the blood. Intoxication occurs at a concentration of approximately 1-2 g / l (100 - 200 mg%). At 3-4 g / l (300-400 mg%) developed severe Institute ¬ intoxication. Lethal concentration is from 5 to 8 g / l (500 - 800 mg%). In the treatment of alcoholic coma should first establish a hell ¬ kvatnoe breath. Held WC oral purified upper airways. To reduce the secretion of salivary and bronchial glands atropine.

Assign oxygen. If necessary, carried ¬ stvlyayut mechanical ventilation. It is also useful introduction analeptikov (korazol, kordiamin, caffeine, etc.). When hemodynamic disorders, symptomatic therapy. It should also wash out the stomach. In addition, a correction of the acid-base equilibrium (intravenous sodium bicarbonate). In severe condition of the patient hemodialysis. In case of severe nausea possible use of antiemetics (metoclopramide, etc.). In connection with the violation of thermoregulation such patients should be warm

Chronic poisoning with ethyl alcohol (alcoholism) is characterized by a variety of symptoms. Particularly affected the higher nervous activity and knowledge. Reduced mental performance, attention, and memory. There may be mental disorders (Delirium tremens, Korsakoff's psychosis). Affected and peripheral innervation (polyneuritis can occur).

Serious disorders and marked by internal organ ¬ new. For example, accompanied by chronic gastritis, alcoholism, cirrhosis, fatty heart and kidneys. If alcoholism is a gradual mental and physical degradation of the individual. Alcoholism treatment is carried out in hospitals. The main task is to stop accepting ethyl alcohol and in the development of a negative attitude to it. Cancellation of ethyl alcohol must be gradual, as abrupt discontinuation of its use can cause severe phenomenon of deprivation, including exacerbation of mental disorders (eg, stroke, delirium tremens). One of the drugs used in the treatment of alcoholism is the teturam (Antabuse, disulfiram).

Assign teturam in conjunction with the acquisition of small amounts of ethyl alcohol. Teturama mechanism of action is that it delays the oxidation of ethyl alcohol to acetaldehyde level (presumably, it inhibits the aldehyde). The accumulation of the latter ¬ him in the body causes intoxication that followed. Extremely painful sensations. There is a feeling of fear, pain in the heart, headache, hypotension, diaphoresis, nausea, and vomiting

The course of treatment for patients Teturamom produces a negative reflection on ethyl alcohol. Teturamom treatment should be carried out with care, under the supervision of a physician. The patient should be well oriented in the fact that even a slight overdose of alcohol ethyl ¬ Vågå on the background of teturama can lead to death. Teturam not recommended for persons older than 50 years, as well as cardiovascular disease, liver disease, kidney disease and metabolism. There is a long-acting drug teturama, called esperal (radoter). Tablets esperal implanted in the sub ¬ cutaneous tissue.

Sometimes to generate negative conditioned reflexes use of centrally acting emetic - apomorphine (also melt ¬ A combination with the reception of ethyl alcohol). Furthermore, in the treatment of alcoholism are widely used various psychotropic drugs. The positive effect in the treatment of alcoholism ¬ SRI, especially in the development of polyneuritis, give thiamine.

Drug treatment of alcoholism should always be combined with psychotherapy. Existing drugs can reduce the consumption of ethyl alcohol ¬ Vågå only in some patients and only for a few months. Unfortu ¬ leniyu enough effective drugs that suppress the craving for ethyl alcohol, no.

Hypnotics By hypnotic include means to facilitate the development and provision ¬ zations sleep. They promote falling asleep and provide the necessary amount of sleep ¬ directly. By the nature of the influence of the central nervous system and the lack of selective classic hypnotics (barbiturates, Alif ¬ cal compounds) are substances such as drugs.

By the nature of the influence of the central nervous system and the lack of selective classic hypnotics (barbiturates, Alif ¬ cal compounds) are substances such as drugs. Hypnotics By hypnotic include means to facilitate the development and provision ¬ zations sleep. They promote falling asleep and provide the necessary amount of sleep ¬ directly. By the nature of the influence of the central nervous system and the lack of selective classic hypnotics (barbiturates, Alif ¬ cal compounds) are substances such as drugs.

Hypnotics are classified based on the principle of action and chemical structure.

I. Hypnotics with narcotic 1. Heterocyclic compounds  Barbituric acid derivatives (barbiturates)                                               Phenobarbital Barbital barbamyl Barbital sodium-sodium etaminal                       2. Aliphatic compounds                   Chloral hydrate bromisoval P. Hypnotics group of tranquilizers                          Benzodiazepines                                       Nitrazepam Sibazon                                                                                  (Diazepam)