"Anesthetic drugs"

1. Overview of the stages of anesthesia

2. General characteristics of narcosis

3. Indications of narcosis.

4. Classification of narcosis.

5. Pharmacodynamics, pharmacokinetics of narcosis.

Plan of lecture

generate knowledge about drugs for anesthesia.

The aim of the lecture:

- To characterize the stages of anesthesia;

- To introduce the general notion of anesthetic drugs;

- Explain the indications for use of narcosis;

- Describe the classification of narcosis;

- To reveal features of pharmacodynamics, pharmacokinetics of anesthesia.

Pedagogical objectives:

MEDICINES regulatory functions

CENTRAL NERVOUS SYSTEM

A considerable number of known substances with which you can control many functions of the central nervous system. These by-worn a variety of chemical compounds that affect the state of mind and emotions that reduce the perception of pain, promote the development of sleep, causing narcosis and others.

The basis of most neurotropic agents on the central nervous system is the ability to modify the process of interneurons (synaptic) excitation transfer. Depending on the direction of the effects arising in this distinguished and stimulating inhibitory substance type. In turn, each of these groups conventionally divided into a general matter and selective action.

Distinctive properties of the substance "common action" is the absence of selective effect on certain centers or function. They

interfere with the activity of the central nervous system at all levels. A typical example of such substances are means of anesthesia. They have a pronounced inhibitory effect on the transfer of excitation in the central link reflexes, becoming isolated in the brain, spinal cord

and medulla oblongata. This leads to loss of consciousness, sensitivity and suppression of most reflexes.

Substances with a so-called selective action imushchestvenno influence on the pre-defined points or functional systems without disturbing the central nervous system. Such drugs include analgesics (morphine group), antiparkinsonian agents, tranquilizers and others. These groups of substances are of varying degrees of selectivity of certain venues and the central nervous system. Selectivity (mostly) the action of drugs associated with neodin-quark-sensitivity to them different synapses due to differences in their structural and neurochemical organization of different localization, the complexity of reflex pathways, functional state RELEVANT centers.

Neurotropic agents can affect different stages of the synaptic transmission (in excitatory and inhibitory synapses), in particular:1) synthesis of the neurotransmitter;2) deposition of the mediator;3) The process of liberation of neurotransmitter from nerve endings;4) interaction with neurotransmitter receptors of the postsynaptic and presynaptic mem- brane; neuronal uptake mediator or its metabolites;5) ekstraneyronalny capture mediator;6) The enzymatic conversion of the mediator.Note that neurotrophic agents capable of influencing the many effects of physiologically active endogenous substances as a mediator, and a modulating action (acetyl-tilholin, norepinephrine, serotonin, γ-aminobutyric acid, neyropepγtidy et al.)....

Some neurotropic drugs have a normalizing effect on the energy metabolism of neurons. For a comprehensive understanding of the mechanisms of occurrence of certain effects is necessary to have many data. So, you want to define centers or association neurons that are most sensitive to the drug, t. E. The localization of its action. You must also set the stages of synaptic transmission, which vary most significantly, and to determine the biological substrate is the "target" for the pharmacological agent. Finally, it is important to find out what are the mechanisms of interaction of the drug with the receptors, endogenous physiologically active substances and so on. D.

Some neurotropic drugs have a normalizing effect on the energy metabolism of neurons. For a comprehensive understanding of the mechanisms of occurrence of certain effects is necessary to have many data. So, you want to define centers or association neurons that are most sensitive to the drug, t. E. The localization of its action. You must also set the stages of synaptic transmission, which vary most significantly, and to determine the biological substrate is the "target" for the pharmacological agent. Finally, it is important to find out what are the mechanisms of interaction of the drug with the receptors, endogenous physiologically active substances and so on. D.

Means of anesthesia (general anesthetics and drugs)Substances in this group produce surgical anesthesia. This condition is characterized by reversible central nervous system depression, co-Thoroe manifest loss of consciousness, sensitivity suppression (primarily pain) and reflex reactions, decreased tone of the skeletal muscles. This definition adopted in anesthesiology includes only the outward signs of anesthesia, which is considered in relation to the whole body.All of the major manifestations of the action of narcosis due to the fact that they are oppressed interneurons (synaptic) the transfer of excitation in the central nervous system. This disturbed the transmission of afferent impulses vary corticosubcortical relationship function of the diencephalon, midbrain, spinal cord, and so on. D. The resulting functional disintegration of the central nervous system associated with impaired synaptic transmission and causes the development of anesthesia.

Lack of selectivity action of narcosis and high variability in their chemical structure gave reason to assume that they apparently do not interact with any specific receptors. In sufficient concentrations, they have the same type depressing effect on the various neurons. Obviously, there is a non-specific physico-chemical bonding with their neuronal membranes (except axonal membrane on which a drug concentrations, they apparently have no effect) due to the interaction with the lipids, and (or) a protein, and possibly also with molecules water covering membrane. This leads to disruption of membrane function and possibly reversible changes its ultrastructure. One of the manifestations of the interaction of narcosis with postsynaptic neuronal membrane is the change in permeability of ion channels, which disrupts the process of depolarization and therefore interneuronal transmission of impulses.

It has also been suggested that a number of narcosis. may increase the intracellular concentration of calcium ions, reducing their capture mitochondria. This causes hyperpolarization of the membrane, increased permeability to potassium ions in general and - reduction of neuronal excitability.It is also possible presynaptic action of these drugs, while leading to a reduction in the release of excitatory neurotransmitters (e.g., acetylcholine).

However, should not totally exclude the possibility of more specific actions for specific types of receptors for at least certain of narcosis. As an argument, you can use data on different effect of ether and methoxyflurane on the stimulatory effects of acetylcholine and L-glutamate in relation to olfactory cortex neurons. Furthermore, in experiments on peripheral receptors has been shown that the stimulatory effect methoxyflurane blocks L-glutamate and does not affect the inhibitory effect of γ-aminobutyric acid. However, these differences are valid for specific drugs, rather than for all of narcosis in general, ie. E. It is not a common pattern, and the specificity of action of drugs specific chemical structure.

Possible principles of intermolecular interaction of narcosis with elements of the membrane (receptor) neurons were studied extensively. Mainly studied the interaction of narcosis with neuronal membranes in general and their components: lipids, proteins and water. In this regard, there were relevant biophysical theory of narcosis (adsorption theory, the theory of cell permeability, lipid and protein theory, the theory of hydrated microcrystals et al.). However, they are not universal, since the concern only of limited series of compounds. In addition, these theories are based generally on model experiments, which does not allow to transfer patterns obtained on condition of the whole organism.

Have been proposed and biochemical theories to explain the ability of anesthesia anesthetic drugs inhibit the metabolism of

neurons of the central nervous system. Indeed, a number of drugs reduces the consumption of brain tissue oxygen (eg .tiopental

sodium). However, this property is not shared by all of narcosis. In addition, changes in the biochemistry of neurons can be

interpreted as a consequence of anesthesia, but not its cause.

None of the existing theories do not explain the mechanism of inhibitory action exhaustively anesthetic drugs on synaptic transmission at the molecular level. And hardly can be created unitary theory. If we compare the chemical structure of narcosis, it is difficult to allow interaction with the membrane of neurons so different in chemical structure soedi¬neny (from inert gases to steroid compounds) would be the same. Indeed, gaseous and volatile liquid anesthetic agent can exhibit biological activity only by hydrophobic (Van der Waals) interactions. However, binding to the membranes (receptors) neurons neingalyatsionnyh means for anesthesia may be supplemented by hydrogen bonds, and also due to the formation of partial charges. In addition, it is possible that the substrate interacts with the means of anesthesia different chemical structure may be different. Thus, the question of the molecular mechanism of action of anesthetic drugs remains open.

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

Gaseous substances

This group includes nitrous oxide, cyclopropane, ethylene. The most widely used in medical practice have received the first two drugs.Nitrous nitrogen - practically nontoxic agent has no irritating properties. Negative influence on parenchymal organs has not. Side effects during the operation in the concentrations used did not cause.The main drawback of nitrous oxide - low drug activity. It causes anesthesia at a concentration of only 94-95% of the inhaled air. Use such a concentration is not possible, as this occurs abruptly hypoxia. In this regard, a mixture of anesthesiology typically 80% nitrous oxide and 20% oxygen. It does not develop the necessary depth of anesthesia and there is insufficient relaxation of skeletal muscles. At best, the effect reaches the entry-level stage of surgical anesthesia. Accordingly, the nitrogen oxide is usually combined with other more active agents (e.g., ftorotanom) and with a curare-like substances. Termination of inhalation of nitrous oxide leads to a rapid awakening without aftereffect phenomena. The drug is readily released unchanged.

Nitrous oxide is used not only for inhalation anesthesia during surgical procedures, but also in myocardial infarction and other conditions involving severe pain.By gaseous anesthetic drug is also cyclopropane, which is a chemically trimethylene. Different from nitrogen Zakir higher analgesic and drug activity. Causing deep anesthesia at a concentration of 20-25 vol.% In the inhaled air. Anesthesia occurs within 3-5 minutes, with little or no stage of excitation. Its depth is easily adjustable. Expressed relaxation of muscles. Termination cyclopropane inhalation leads to rapid cessation of anesthetic (in minutes). The drug is readily released unchanged.The main disadvantage is its cyclopropane cardiotropic action proyavlya¬yuscheesya changes in heart rate. Often there are bradycardia, ventricular extrasystoles and other forms of arrhythmias. Given that cyclopropane sensitizes the myocardium to adrenaline, the use of the latter (as well as norepinephrine and ephedrine) is contraindicated, as this can cause serious heart rhythm disturbances up to ventricular fibrillation. Arrhythmias such origin is particularly effective β-blockers are eliminated (Inderal et al.).Blood pressure at the cyclopropane anesthesia increased. Oppressed breathing. Often marked acidosis. Negative effect on the liver has no cyclopropane. Renal function during anesthesia reduced. May increase the level of sugar in the blood and urine. Mucous membranes cyclopropane not annoying.Cyclopropane flammable. Nitrogen oxide itself is not flammable, but supports combustion.

TOOLS FOR not inhalation anesthesia

Means for neingalyatsionnyh anesthesia is usually used parenterally, enterally less. Of parenteral routes of administration the most widely used intravenous route. Existing drugs for intravenous anesthesia for the duration of the action may be represented by the following groups:1) short-acting (duration of anesthesia to 15 min) - propanidid, ketamine;2) The average duration (duration of anesthesia 20-50 min) - thiopental sodium, predion;3) long-acting (duration of anesthesia 60 minutes or more) - sodium hydroxybutyrate.Propanidid is an oily liquid, all other drugs are powdery substances. Apply tools to neingalyatsionnyh anesthesia in solutions.

Propanidid (epontol, sombrevin) has a very rapid onset of anesthesia (30-40 s) without a stage of excitation. Stage of surgical anesthesia lasts about 3 minutes, another 2-3 minutes recovering consciousness. The short duration of action due to the rapid hydrolysis propanidid its plasma cholinesterase. After narcosis depression of the central nervous system were observed. Serious side effects propanidid causes. Before the onset of anesthesia may be short hyperventilation apnea, but the stage of surgical anesthesia breathing normal. Possible slight tachycardia, hypotension some. At the beginning of the preparation of a number of patients the muscle twitching. Propanidid enjoys a mild irritant that is usually manifested by hyperemia and pain along the vein. Perhaps the formation of blood clots. Propanidid used for induction of anesthesia and of short duration operations. It is particularly suitable for ambulatory practices, as in 20-30 minutes completely restored psychomotor functions.Longer anesthesia cause barbituric acid derivatives - thiopental sodium, as well as steroid compound - predion.

Sodium thiopental (Pentothal sodium) in intravenous anesthesia is approximately 1 minute without excitation step. Duration of anesthesia, 20-30 minutes. Transient effects associated with redistribution of the drug in the body and, in particular, its accumulation in large amounts of adipose tissue. Inactivation of thiopental sodium occurs gradually in the liver.With the drug may experience twitching muscles. In some patients there is a laryngospasm. Thiopental sodium should be injected very slowly, since the rapid growth of concentration manifests its inhibitory effect on the respiratory and vasomotor centers, as well as the heart. The rapid introduction of the drug may lead to apnea and collapse. Thiopental sodium peculiar and some local irritant effect. It is used for induction of anesthesia or short-term surgical interventions.Pharmacodynamics and F PMA coca tics barbituric acid derivatives r e e k with Nala (geksobarbital sodium, sodium evipan) are similar to those of thiopental sodium. Note that hexenal has a more pronounced inhibitory effect on the heart. Furthermore, it is more likely than sodium thiopental, provoke convulsions. Indications for use are the same as for sodium thiopental.

For intermediate-acting drugs also applies predion (viadril, gidroksidiona sodium succinate). According to chemical structure of the stero¬idam, but does not have hormonal properties. Drug Activity prediona insufficient. In this regard, it is used mainly for the induction of anesthesia. Depending on the dose of the maximum effect developed after 5-15 min step without excitation. The total duration of anesthesia is 20-30 minutes. Predion is quite pronounced muscle relaxation. Prediona toxicity is low. Respiration, blood circulation and the function of the parenchymal organs, usually not affected. Only occasionally there is some reduction in blood pressure, rarely - PVCs. The main side effect prediona - irritant effects, which may occur in the defeat of the endothelium and the development of thrombosis and thrombophlebitis. Less commonly thrombophlebitis developed using the drug "viadril G".Of the steroid anesthetic drugs are also used as l mes and n (a mixture of two steroid compounds alfaksolona and alfadolona acetate). When intravenous anesthesia occurs within 40-60 seconds and lasts for about 15 minutes. The short duration of action is mainly due to a rapid metabolism in the liver altezina and its redistribution in the tissues. Sometimes causes tremor, muscle twitching, Vozimrkna neznachitel¬naya hypotension. A small percentage of patients with postoperative nausea and vomiting. There are cases of hypersensitivity to altezinu.

Duration of action has sodium hydroxybutyrate. Is a synthetic analog of a natural metabolite found in the central nervous system. It penetrates the blood-brain barrier. Has a sedative, hypnotic, narcotic and antihypoxia action. The analgesic effect is to a small extent. In combination with other anesthetics and analgesics sodium oxybutyrate enhances their activity, without affecting the toxicity. It produces marked relaxation of skeletal muscles. Increases the resistance of the tissues of the brain and heart to hypoxia. Drug Activity Sodium hydroxybutyrate insufficient, so it is administered in large doses. Step of excitation usually do not occur. With rapid infusion, however, the possibility of instituting and twitching muscles. Stage of surgical anesthesia occurs within 30-40 min after intravenous injection (injected drug slowly). L½-duration anesthesia 3 hrs.

Sodium hydroxybutyrate administered by ingestion. It is well absorbed from the small intestine and after 40-60 minutes of anesthesia causes that continues l½-2½ hours.The toxicity of sodium hydroxybutyrate low. Negative impact on circulation and respiration in narcotic doses does not have. Possible vomiting. Sometimes develop hypokalemia. In case of overdose there is oppression breathing center.Used mainly for drug induction and basicanesthesia for labor analgesia with hypoxic brain edema, as a means protivoshokovogo, with the aim of calming and hypnotic action.

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).

Combined use of anesthetic drugs with drugs FROM OTHER pharmacological groups

The combination of anesthetic drugs on the action with a variety of drugs aimed at strengthening a narcotic effect or to eliminate side effects or drawbacks of the drugs. To prepare the patient for surgery (premedication) use sedatives (eg, tranquilizers, antipsychotics), and anesthetic agents (from the group of morphine). Widespread as atropine and atropine means warning reflexes on heart and breathing and reduces the secretion of bronchial and salivary glands.Means of anesthesia is often used with curare-like drugs (tubocurarine chloride, ditilin et al.), Providing during surgery required relaxation of skeletal muscles. If you want to manage hypotension on the background of anesthesia, intravenous ganglion blockers short-acting (eg gigrony). Often, funds for anesthesia combined with preparations for neuroleptanalgesia. The latter is achieved by a combination of active analgesic morphine group with neuroleptics (eg, fentanyl + droperidol). This leads to the development of general anesthesia, the suppression of autonomic reactions, mental retardation, and in large doses - and loss of consciousness

The conclusion of the lecture.In the appointment of drugs is necessary to consider the individual characteristics of the organism and its status as drug sensitivity varies depending on the age, sex, genetic factors, the effect of drugs may also depend on the state of the organism, in particular a pathology in which they are assigned, is changed accordingly and the intended effect of drugs.Thus, a general practitioner in the selection and appointment of narcosis is necessary to analyze their pharmacokinetic and pharmacodynamic characteristics and factors affecting them.

Additional:

1. Mashkovskii MD Drugs. Directory. M .: Medicine, 2001, 2005.

2. Reference Vidal. M., 2010, 2011.

3. Fakhrutdinov SF Pharmacology. Textbook. Tashkent: Ibn Sina, 1995.

4. Makhsum MN, MM Malikov Pharmacology. Textbook. Tashkent: Ibn Sina, 1997.

5. Katsung BG Basic and Clinical Pharmacology. Monograph. St. Petersburg - Moscow, 1998.

6. Khakimov ZZ, Asimov MM, Zaitseva OA, Radzhapova SZ Umum recipe. Textbook. Tashkent, 2005.

7. Holmatov HH, Kharlamov, IA Major medicinal plants of Central Asia. Monograph. Tashkent: Medicine, 1984.

8. General medical practice. Clinical guidelines and formulary. Under. Ed. IN Denisova, JL Shevchenko, FG Nazyrova. - M .: GEOTAR-Media, 2005.

9.: //www.cibis.ru/catalogue/pharmacology_pharmacy_toxicology/a/sites/

52185.html; : //medvedev-ma.narod.ru/farmakologia/0.htm;

10.http: //max.1gb.ru/farm/;

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