A local anesthesia.

Inhalation anesthesia. Noninhalation anesthesia.

 

Surgery is a form of service to man. It is a body of knowledge and experience developed by man to meet human needs in certain fields and has come to be entrusted to a group of individuals who have devoted themselves more or less successfully to acquiring this requisite body of knowledge and experience.

Its boundaries and those of internal medicine are more distinct in the popular mind than in practice. The practitioner of internal medicine generally abstains from performing formal operations and by doing so has more time which he can devote, if he will, to the study of diagnostic problems, for consideration of psychosomatic difficulties encountered by his patients, and for study of advances in the basic sciences or to clinical investigation.

A number of years ago one of our senior surgeons made the statement that internal medicine was becoming more and more surgical in its outlook, and, in all fairness, one must add that in the last third of the twentieth century, general surgery has become more and more steeped in medicine and the basic medical sciences.

There is no more basic objective for the surgeon than the precept of the late John B. Deaver who said that a surgeon must be a medical man and something more-not something less.

Anyone who enters the field of surgery to escape from the rigorous mental discipline required to think straight in medicine is likely either to fail or, worse, do a great amount of harm.

An OPERATION (from the Latin word operari to work) is a mechanical influence upon the tissues and organs with the curative or diagnostic purpose.

During several decades an operation was a source of severe pain and mortal danger, and this made several patients reject it, even in the cases when their life was directly threatened. Different operations, even quite complicated ones, were performed long also, during the pre-aseptic era before the anesthesia came into medical practice. Inability to carry out painless operations, the lack of knowledge about the conditions of development and prevention of the wound infection, as well as the insufficiency of means to cope with acute hemorrhage, made the surgeons of that period perfect the technique of the operations with the main purpose to complete them in minimal terms. This rapidity of the operations execution often was to the detriment of the thoroughness of performing some important details of the operation, and needed perfect knowledge of anatomy (the anatomical school in surgery).

At present the operation risk has significantly diminished, and the surgery moved on to the physiological school.

The essence of the physiological school in surgery is in thorough investigation of the organs and systems functions in the patient suffering an illness, and in studying the dynamics of changes in these functions before, during and after operation. If a surgeon finds deviations from normal functions, his task is to take measures to provide for their normalization.

A surgeon is required not only to be quick in operating, and to have a good knowledge of anatomy and physiology, but also to be calm, confident in his actions, and to observe his patients with great care.

Experience shows, that there are no patients, who are completely indifferent to surgical intervention, although the external expressions of their feelings are different. Therefore, to achieve success in the intervention, it is extremely important for a surgeon to be able to gain understanding of a patients individual features, the state of his nervous system, and to make his better in the good outcome of the operation stronger.

All the operations are divided into HAEMORRHAGENIC (bloody), in the course of which the skin, mucous membranes, muscles as well as other tissues and organs of the body are incised; and BLOODLESS, in the course of which the external integuments remain intact. For example, the setting of a dislocated joint is a bloodless operation. Besides that, there are CURATIVE and DIAGNOSTIC operations.

The examples of diagnostic operations are: biopsy, pleurocentesis or abdominal paracentesis, spinal, joint or other punctures, and endoscopic investigations (cystoscopy, bronchoscopy, esophagoscopy, gastroscopy, thoracoscopy, laparoscopy etc.). All the diagnostic operations are used for establishing or clarifying the diagnosis only after all the other diagnostic methods have been used. Diagnostic laparoscopy involves certain risk, therefore it is implored only after all the other possibilities of establishing a patients diagnosis are exhausted.

The CURATIVE operations can be RADICAL, when the affected organs or tissues are discissed (cut) or ablated (incision of an abscess, appendectomy, resection of the stomach, cholecystectomy, etc.). Radical operations can be BROADENED (comprehensive) and COMBINED. For example, if a tumor of the stomach has grown into the surrounding tissues, besides gastrectomy, ablation of the spleen and/or resection of a liver lobe, etc., are performed.

PALLIATIVE operations do not liquidate the cause of the disease, but only improve the state of the patient. For instance, if a tumour closes the lumen of the intestine and there is no possibility to ablate it radically, a loop of intestine is taken out, fixed to the external abdominal wall and cut open.

As to URGENCY, there are:

1.       operations of SPECIAL URGENCY,

2.       URGENT and

3.       PLANNED operations.

OPERATIONS OF SPECIAL URGENCY are carried out as soon as possible, during the first 2 hours after establishing the diagnosis (such as appendicitis, perforated stomach, ulcer, incarcerated hernia, acute intestinal obstruction, etc.). In some cases an operation is carried out during the nearest few minutes on indication vitals cases like acute hemorrhage or tracheostomy.

URGENT operations are performed during the first days after the hospitalization, because the quickly developing process may later make the patient inoperable (malignant tumors, etc.).

PLANNED operations can be performed in ONE, TWO or MANY stages. In most cases the operations are concluded in one stage (cholecystectomy, resection of the stomach, etc.). If a patients state is assessed as grave, and the operation is complicated, the risk increases. In such cases the operation is divided into two or more stages. For example, operations for appendicular infiltrates, tumors of the large intestine with obstruction, the migrating stem after Filatov, etc.

The operations are divided into 4 groups:

1.       clean;

2.       relatively clean (when the lumen of the alimentary tract is cut open);

3.       contaminated (when the content of the internal organs gets into the wound);

4.       dirty, or primary infected.

At last, we have summary:

Operation working special mechanical influence on tissues with ambulate aim.

Surgical operations we can divide on:

1.       extrimal operations (urgent);

2.       emergency;

3.       planned (non urgent).

Instead of that we divide operations on:

-            radical

-            palliative.

Radical operation, which we take away pathological tissue, part or whole tissue; we can except return of illness.

Palliative this are operations, which we do in aim to take away destruction for live or make it more easer.

Operations can be one-stage or multi-stage. When we deal with one stage operation, we do everything one by one without break. In compare with multi stage operation we should have some break for reconvenes (fig. 1).

Fig. 1. An 81-year-old male with blastomycotic ulcer of left leg of 5 months duration. Diagnosis made by demonstrating blastomyces in discharge at margin of wound by hanging-drop technic.

 

During surgical practice we can crass upon with some situations when question about doing operation will be solving only during operation. It deals with oncological diseases, tumors one or another part of body. In this situation we think that radical operation is the best. But then we invite to the inside of body we see that radical operation is too late because of metastatyc spread of tumor. This type of operation we call tried (diagnostic, exploratory).

Instead of such classification of surgical operation we can divide with

-            typical and

-            non-typical operations.

Typical operations work very briefly and graphics. We can choose to that part broken part of body.

Next steps are:

-            open and

-            closed operations.

Closed are reposed bones (fig. 2), some kinds of special operations (endoscopic).

Microsurgical operations work under the influence of from 3 to 40 times with help raisin glasses of microscope.

Fig. 2. Manual one-moment closed reposition during fracture of radius

 

Endoscopical operations do with help of endoscopical tools. Through endoscope we complete excision, take away polyps of ventricle, urinary bladder, mucous membrane; hemostatic, delusion.

Endovascular operation is kind of closed operation with help of catheter.

Reoperations can be planned (multi-stage) or forced under development of post operational complications, treatment can be only in surgical way. For example: relaparotomy in patients with parting of the suture of intestinal anastomosys with development of peritonitis.

Surgical operation consist:

-            operative access;

-            operation procedure;

-            suturing of tissue.

THE INDICATIONS TO AN OPERATION

The indications to an operation can be ABSOLUTE, RELATIVE and VITALLY IMPORTANT. The last indications are established when a patients life is directly threatened.

The indications are ABSOLUTE when the disease can be cured only by an operative method.

RELATIVE indications concern, for instance, the planned operations, that can be postponed or declined for the time being, with no serious harm to the patients health.

The same illness can entail either vitally important, or absolute, or relative indications to operation, depending on the urgency of the patients state. For example, a complicated duodenal ulcer can involve vitally important indications to operation (profuse hemorrhage, that can not be stopped otherwise), absolute indications (stenosis) or relative indications (when other methods of conservative treatment have not yet been tried).

A surgeon must think over the PLAN OF OPERATION and write a PRE-OPERATION EPICRISIS, which includes: the grounded diagnosis, indications to operation, plan of operation, method of anesthesia and patients consent to the operation.

There are THREE MAIN STAGES in a surgical operation:

1.       the pre-operation period and preparation of the patient to the operation;

2.       the operation itself, with its particular features;

3.       intensive care and nursing of the patient during the post-operation period.

The positive effect of a surgical intervention is granted by thorough performance of all these stages by the surgeon and the personnel.

The PRE-OPERATIVE PERIOD begins at the moment of a patients hospitalization or his consultation at the outpatient department, and ends when the operation starts.

The general object of the pre-operation period is to decrease the danger of the operation as much as possible. While preparing the patient to the operation, the surgeon should foresee all its possible dangers and take the necessary measures aimed at their prevention.

During the pre-operation period the surgeon has to do number of tasks, namely to:

1.       Making the diagnosis, determine the indications and contraindications to the operation, choose the optimal kind of surgical intervention and method of anesthesia;

2.       Reveal the complications of the main disease and the concomitant illnesses;

3.       Determine the state and extent of dysfunction of the respiratory and cardiovascular systems, liver and kidneys;

4.       Carry out a complex of therapeutic measures, promoting the improvement of the impaired functions (normalization of the blood pressure, etc.), and sanitation of the mouth and tonsils to prevent possible infection;

5.       Create functional reserves in the patients organism, improve the state of his immunity system;

6.       Prepare the patient to the operation psychologically to decrease his emotional tension (fig. 3).


The duration of the pre-operation period depends on the nature of the disease, the general state of the patient, the urgency of the operation and the volume of the surgical intervention. In the operations of surgical urgency (intense hemorrhage, acute appendicitis, perforated gastric ulcer, etc.) the pre-operation period is shortened to a necessary minimum, and only the simplest measures are taken.

As it was mentioned before, during the pre-operation period the surgeon has to foresee the possible complications, which can happen in the process of surgical intervention, so that he can prevent them in time.

Thus, during the period of preparation to the operation measures are taken to prevent its possible complications, and to improve the functioning of impaired organs.

The pre-operation period of the planned operations is divided into the:

1.       remote;

2.       near and

3.       immediate pre-operation periods.

During the REMOTE period a patient, for instance can receive a course of treatment at a sanatorium. During the period NEAR to the operation (7 to 15 days) the general somatic state of the patient is normalized or improved. And IMMEDIATELY before the operation the sanitary treatment and evacuation of the bladder content is performed. There exist IMMEDIATE pre-operation measures, which are compulsory in the preparation to most operations (general bath, shaving of the hair on the body, enema, evacuation of the bladder content, etc.), and also SPECIFIC measures for preparation to special kinds of operations (such as evacuation of the stomach content in pyloric stenosis, lavage of the large intestine before its resection, etc.).

The preparation to the surgical intervention includes, besides the above-mentioned measures:

1.       psychological preparation;

2.       general somatic preparation;

3.       local preparation.

PSYCHOLOGICAL PREPARATION. The patients mental state is very important for the outcome of the operation and the postoperative period. The ability of the medical personnel to relieve the psycho trauma cased by the pending operation in a patient, has a favorable influence on the course of the pre-operation and post-operation periods. The medical personnel must spare a patients nervous system during all the period of treatment. In the pre-operation period the contact between the doctor and the patient is especially important. The capacity of a surgeon to persuade the patient, inspire in him confidence that the outcome of the operation and the treatment will be good, gives the patient new powers. In the case of grave or incurable diseases (such as malignant tumors) the doctor intentionally conceals the truth from the patient, otherwise he will lose the last hope in recovery, and the illness will progress faster.

In the pre-operation period it is important to cope with sleeplessness. With these purpose hypnotic drugs, tranquilizers, anesthetics or hypnosis are used.

In all cases the patients consent to the operation has to be obtained. If the patient is unconscious or isnt able to give a definite answer because of a mental disorder, the question of surgical intervention is solved by a medical consultation. To operate a child the parents consent is needed.

GENERAL SOMATIC PREPARATION

To produce better results and render surgical intervention safer, it is necessary to consider carefully the patients general physical condition before the operation. The patient is therefore thoroughly examined and the method of anesthesia as well as of the operation is chosen with due regard for the condition of the internal organs (heart, lungs, kidneys, etc.).

During the operation the cardiovascular system functions very intensively, so before big operations special preparation is needed. This especially concerns patients with high blood pressure, circulation insufficiency and disturbances of the heart rhythm. In such cases a patient must to hold the bed regime, the quantity of liquid he drinks should be limited and it must be prescribed heart glycosides, diuretic and other remedies.

A variety of chronic disease processes are associated with anemia. In some instances, these represent visible, external losses, such as in carcinoma of the caecum. Other instances are far less clear and are associated with chronic infection or with chronic inflammatory processes of the bowel. All these patients fit a pattern in which there is substantial blood loss associated with reduction of red cell mass. Indeed, such patients have a normal total blood volume as they compensate for a significantly decreased red blood cell volume by expansion of the plasmavolume to supernormal levels. While acute intravascular volume deficiencies are manifested by an increased pulse rate with decreased blood pressure, these are poorly tolerated on a chronic basis. Such volume is restored by expanding the plasma volume, often at the expense of the extra cellular fluid, to compensate for the loss of or nonproduction of red cell mass.

To prevent thrombosis and embolism the protrombin index is established, and if necessary anticoagulants are prescribed.

In 5 to 10% of all operations, especially in the thoracic and abdominal cavities respiratory dysfunctions and lung disorders appear, especially in patients who had respiratory organs pathology before the operation. Therefore, before a planned operation is performed, it is necessary to cure inflammation in the paranasal sinuses, acute and chronic bronchitis, pleuritis and pneumonia. Operation is contraindicated to patients with acute rhinitis, bronchitis and pronounced pulmonary emphysema.

In the preparation of the alimentary tract to the operation long-term absolute fasting is an undesirable, as well as taking laxative or repeated large intestine lavage, because such measures cause acidosis and acido-alkaline disbalance, decrease the intestine tone and promote hemostasia in the mesenteric vessels. This can result in serious intoxication, vomiting, meteorism and oliguria. Therefore the quantity of food should be limited only in the evening before the operation.

An enema should be used only if there is no natural discharge of excrement. The exclusion from this rule is the case of operations on the large intestine or perineum.

An important role belongs to the sanation of the mouth cavity and treatment of cariotic teeth. The stomach must be empty before operation. In the case of gastric hemorrhage the stomach lavage before the operation is contraindicated.

To improve the liver function it is necessary to enrich its reserves of glycogen. This is achieved by good nutrition, injections of glucose, vitamins C and B12, metionine and lipocaine.

Considering that it is often necessary blood transfusion during an operation, and this can increase the need in good functioning of the kidneys. It is important to check the functional state of the kidneys, by performing kidney tests. Before the operation the bladder should be emptied.

LOCAL PREPARATION. Before the operation a thorough examination of the skin is necessary. If any kind inflammation is discovered in the place, where the operation is to be performed or near to it, the surgical intervention is postponed if there are no vital indications to the operation.

The day before the operation the patient must take a bath and change his underwear. In the morning before the surgical intervention the operation area should be prepared washed with soap, and the hair should be shaved.

THE CHANGES IN THE ORGANISM DURING THE POST-OPERATION PERIOD

The post-operation period (see appendix 6) includes the time from the end of the operation until the moment, when the patient recovers and can return to work. The reconvalescention period is as important as the surgical operation itself.

The POST-OPERATION PERIOD IS DIVIDED INTO THREE PHASES:

1.       the early phase the first 3-5 days after the operation;

2.       the late phase 2-3 weeks after the operation;

3.       the remote phase until the patient recovers his capacity to work.

The POST-OPERATION PERIOD can be

1.       SMOOTH OR NORMAL or

2.       WITH COMPLICATIONS.

Fig. 4. Scheme of central venous pressure determination

 

The changes that are observed in the post-operation period can return to the norm during a few days. In 90% of cases changes in the CARBOHYDRATE METABOLISM with hyperglycemia and glucosuria are found. They disappear in 3 or 4 days. These changes exist due to insufficient oxidation of carbohydrates caused by the CNS irritation and endocrine system dysfunction.

In the post-operation period ACIDOSIS may also appear as the result of blood acido-alkaline disbalance. To prevent acidosis early meals and infusions of glucose and insulin are recommended.

CHANGES IN THE PROTEIN METABOLISM with the increase of the blood residual nitrogen level, hypoproteinemia, and increase of globulin fractions. The development of hypoproteinemia contributes to bleeding during the operation. Nutritious food with high protein content, blood and plasma transfusions can compensate this state.

CHANGES IN THE WATER AND ELECTROLYTE METABOLISM are also important in this period. The blood levels of chlorides decrease usually on the first day after the operation and are compensated by infusions of Ringers solution or hypertonic solutions of sodium and potassium chlorides.

Together with the chloride level changes, negative liquid balance is observed, that indicates the dehydratation of the organism. High temperature, high breathing rate, and vomiting or diarrhea can case it.

Water-electrolyte disbalance should be corrected individually. During the first days after the operation 2.5-3 liters of liquid a day should be infused to compensate the losses.

CHANGES IN THE BLOOD COMPOSITION are also very important. In this case leucocytosis is a normal reaction of the organism to the absorption of the protein dissociation products. The reason of anemia is the blood loss during the operation, increased erythrocyte disintegration after blood or erythrocyte mass transfusion. In 75% of cases the blood viscidity increases owing to the heightened level of globulin fractions and the dehydratation of the organism (the danger of thrombosis and embolism increases).

To cope with INTOXICATION caused by disorders in the parenchymatous organs, alimentary tract and endocrine system different solutions are used (isotonic sodium chloride solution, Haemodes, Ringers solution, 10-40% glucose solutions, etc.).

Great attention is given to the activation of patients after operation. This concerns especially elderly people. Breathing exercises and therapeutic physical training are recommended.

 

DISTURBANCES IN THE VITAL ORGANS AND SYSTEMS FUNCTIONING

Disturbances in the functions of vitally important organs and systems are possible both at the early and at the late phases of the post-operation period. The gravity and the number of such disturbances can be limited by thorough investigation of the patient and correct preparation during the pre-operation period, careful, sparing handling of the tissues during the operation and early activation of the patient in the post-operation period.

Psychoneurologic post-operation disorders are usually manifested in pains, sleeplessness, paraesthesias, and sometimes in palsies or psychoses. The intensiveness of pain depends on the volume of the operation, the extent of the tissue traumatisation and on the level of nervous excitability of the patient. The pain is relieved by analgesics (injections of 50% solution of analginum, or 1-2% solutions of morphine, promedolum or omnoponum), neuroleptics droperidolum and haloperidolum or therapeutic narcosis. If there are disturbances of sleep hypnotics, such as barbiturates are prescribed.

Among the disturbances in the cardiovascular system there can be acute cardiac and vascular insufficiency, thrombosis, embolism and infarctions. The medicines used for the treatment of these disorders are: heart glucosides (strophantinum, corglyconum, digoxinum), remedies that tone up peripheral blood circulation (strychninum, coffeinum, ephedrinum, dopaminum), coronarolytics (nitroglycerinum), diuretics (lasix), in the case of thrombosis anticoagulant drugs are prescribed. Oxygenotherapy is widely used for the treatment of cardiovascular disorders.

Respiratory complications include: acute respiratory insufficiency, bronchitis, tracheitis, pneumonia, pleuritis, atelectasis and lung abscess. The development of pneumonia is often promoted by insufficient lung ventilation.

To prevent lung complications it is necessary to keep the patient from undercooling in the operation-room, bathroom or other premises. It is also important to provide careful nursing, respiratory exercises, prescribe antibiotics, inhalations, apply cupping-glasses and mustard plasters, etc.

The most serious complications in the organs of the alimentary tract are localized abscesses in the small pelvis, peritonitis, intestinal obstruction and some others. These disorders are treated by repeated operations, draining of the abdominal cavity and peritoneal dialysis.

Complications in the urinary system are manifested by retention of urine (ischuria), diminishing of the quantity of urine (oliguria, anuria), and inflammation in the renal pelvis (pyelitis) or the bladder (cystitis).

Post-operation oliguria and anuria are of neuro-reflex genesis or are caused by the kidney parenchyma damage. Bilateral paranephral blockade is performed in this case, diuresis-stimulating drugs are used (lasix. mannitolum, aminophyllinum), as well as haemodialysis and haemosorbtion.

Ischuria usually follows operations on the organs of small pelvis. In these cases the bladder is overfilled. The patients are recommended to urinate sitting or standing, a warm water bottle is applied to the lower abdominal area. If necessary - catheterization of the bladder is performed.

To treat pyelitis or cystitis antibiotics and antiseptics for disinfection of the urinary passages (urotropinum, furadoninum, furozolidonum, 5-NOK, nevigramonum, etc.) are used, as well as physical therapy

 

GENERAL, LOCAL AND REGIONAL ANESTHESIA

 

The main kinds of anesthesia

All kinds of anaesthesia divided on general (narcosis) and local anaesthesia.

Narcosis

Narcosis is aimed a temporary state of unconsciousness in the patient (narcotic sleep) and diminution or complete relief of sensitivity to pain (analgesia). General anaesthetics produce loss of consciousness and varying degrees of anaesthesia and muscular relaxation.

Anaesthesia is produced by progressively increasing the amount of the anaesthetic in the inspired air and thus in the blood and brain. Unconsciousness is one of its primary conditions. It results from the reversible reduction of the activity of the cortex and thus induces loss of consciousness. It can be produced by a variety of chemical agents that act on the brain.

Relaxation of sceletal muscles, essential for carrying out certain operations, may be achieved by deep anaesthesia but only for a short time since such narcosis is dangerous. It is replaced by a more superficial anaesthesia involving introduction of drugs which reduce muscle tension. Other factors which cause a drop in body temperature and blood pressure, etc., employed along with relaxants to produce a deeper analgesic effect of the anaesthetic and prevent undesirable side-effects (potentiated anaesthesia). When relaxants are administered such vital function as respiration is arrested deliberately and artifitial respiration is employed (controlled ventilation).

Preparing to the operation (preanaesthetic medication)

Anaesthetist must examine of patient before each operation. The tasks of examination are:

        General condition estimation;

        Peculiarities of anamnesis, connected with anaesthesia;

        Clinical and laboratory data estimation;

        Determination of degree of operational and narcosis risk;

        Method of anaesthesia selection;

        The character of premedication determination.

Premedication (preanaesthetic medication) is introduction of medicinal substances before operation for decreasing of intraoperation and postoperation complications frequency. The main medicinal substances for premedication are:

        Opiates (barbiturates: pentobarbital, phenobarbital; benzodiazepines: nozepam, tazepam);

        Sedatives (diazepam, phenazepam);

        Neuroleptics (aminazine, droperidol);

        Antihistamines (Dimedrol, tavegil, suprasterol);

        Narcotic drug (promedol, morphine);

        Anticholinergic drug (atropine, methacin).

The main schemes of premedication are:

Before the urgent operation the narcotic drug and atropine (promedol 2% - 1,0, atropine 0,01 mg/kg) are introduced.

Before planned operation the usual scheme of premedication includes: at night opiates (phenobarbital 2 mg/kg) and tranquilizer (phenazepam 0,02mg/kg); in the morning (before 2-3 hours to the operation) diazepam 0,14 mg/kg; before 30 min. to the operation - promedol 2% - 1,0, atropine 0,01 mg/kg and Dimedrol 0,3 mg/kg are introduced.

 

Classification of narcosis

1.     According factors which affecting on central nervous system;

        Pharmacodynamic (we have effect by pharmaceutical substances);

        Electronarcosis (electric field action);

        Hypnonarcosis (action by hypnosis).

2.     Accorging of medications introducing;

        Inhalation narcosis through respiratory ways the pharmaceutical substances are introduced. Aperture-mask, endotracheal and endobronchial narcosis are distinguished. In modern time usually the endotracheal narcosis is used.

        Noninhalation narcosis the preparation are introduced not through respiratory ways, but intravenously (mainly) or intramuscularly.

3.     According quontity of preparations:

        Mononarcosis the single preparation is used.

        Mixed narcosis some preparations at one time are used.

        Combined narcosis different narcotic substances during varios time of narcosis are used.

4.     According application on different phases of operation:

        Initial narcosis is short-term. For fast lulling to sleep of patient is used.

        Supportive (main) narcosis this anaesthesia is adjusted to all operation.

        Basis narcosis is superficial narcosis. The preparation of main narcosis and other anaesthetic drug for increasing of primary medicine dose are introduce.

Stages of anaesthesia

Four stages of anaesthesia are distinguished.

1.            Stage of analgesia. The first stage is characterized by partial unconsciousness and diminution of sensitivity to pain. Momentary operations may be performed during this period. Consciousness is gained quickly when the anaesthesia will be discontinued.

2.            Stage of excitement. The second stage is extremely manifested in males, predominantly in drunkards. The possibility of concomitant vomiting makes it dangerous. The latter does not occur if the patient has been properly prepared for the anaesthesia, or when anaesthesia is produced by cyclopropane, nitrous oxide, or by intravenously injections of hexenaland pentothal.

3.            Surgical stage. The third stage is divided into four planes. The first plane is characterized by superficial anaesthesia (the patient being unconscious), loss of sensitivity to pain, a good pulse, and arterial pressure of the same level as before anaesthesia. The pupils are narrowed; the reaction to light and the corneal reflex are retained. Involuntary rapid movements of the eyeballs (nystagmus) occur. The second plane develops as the anaesthesia deepens. Cessation of eyeball movement, constriction of the pupils and their sluggish reaction to light are characteristic of this period. Anaesthesia is conducted in these two planes when relaxants are imployed. The third plane which corresponds to deep anaesthesia is the threshold depth of anaesthesia. Its features are calm and deep respiration, a rhythmical and not frequent pulse, and the absence of the corneal reflex. The pupils are slightly dilatated and their reaction to light is weakened. Anaesthesia is conducted in this plane when relaxants are imployed. The fourth plane occurs only when an excess dose of anaesthetics is administered. During this plane the pupils dilate, respiration becomes shallow and diaphragmatic, and cyanosis develops frequently.

4.            Agonal stage. The fourth stage is that respiratory paralysis and subsequent cardiac arrest. It is characterized by dilated pupils, which do not react to light, dryness of the cornea, disappearance of all reflexes, and complete muscular relaxation. Anaesthesia should never reach this stage. The period of recovery is also distinguished (it is of long duration only on operations performed over a long period of time). During this period anaesthesia becomes more superficial, the tongue tends to fall back, and excitation, vomiting, and respiratory disorders may occur. The patient must be under continuous observation during this period.

 

Regional (Local) Anaesthesia

Regional anaesthesia implies reversible blockade of pain perception or transmission by local anaesthetic drugs, although physical agents such as cold or pressure can act similarly. Topical anaesthesia is results from the application of certain local anaesthetics to skin or mucous membranes (conjunctiva, oral, nasal, and anal). The ability to interrupt nerve conduction with facility, and thus produce anaesthesia by the appropriate use of a local anaesthetic drug, has permitted an almost unrestricted variety of surgery to be safely and painlessly performed in the ambulatory patient. Many local anaesthetic drugs have been given a clinical trial, each with the hope that it would prove to be the ideal local anaesthetic. Thus far, this ideal drug has not been introduced. The ideal local anaesthetic drug should possess the following properties:

1.       It should be capable of producing anaesthesia when applied topically, when used for infiltration anaesthesia, and when injected around a nerve for nerve or plexus block.

2.       It should possess a wide margin of safety so that effective clinical doses do not closely approximate toxic doses.

3.       It should have a selectivity of action confined to nerve tissue.

4.       It should possess low toxicity in doses employed clinically. It should not produce deleterious effects on tissues at the site of injection; not should it produce systemic toxicity following its absorption from the point of administration.

5.       It should produce rapid onset of anaesthesia.

6.       It should ensure anaesthesia of sufficient duration to permit completion of surgery.

7.       It should be completely reversible in its effects. Complete restoration of nerve conduction should occur when absorption of the drug is complete.

8.       It should be stable so that decomposition will not occur with sterilization and exposure to air.

9.       It should be readily soluble in saline or distilled water.

Local Anaesthetic Agents

While many local anaesthetic agents have been introduced and advocated for clinical use, only a few are presently accepted and widely used.

Cocaine Hydrochloride. Cocaine hydrochloride was the first local anaesthetic drug employed clinically. It is the only naturally occurring local anaesthetic. Its use for infiltration and nerve block anaesthesia has long been discarded because of the severe toxic reactions, which it produces. Cocaine hydrochloride is still widely employed as a topical anaesthetic agent and is considered to be superior to other drugs for this form of anaesthesia. A few drops of a solution of 4% cocaine hydrochloride repeatedly instilled into the conjunctival sac will produce complete corneal anaesthesia. Repeated instillations may produce desquamation of the cornea. For this reason, other topical agents have replaced cocaine. More concentrated solutions of cocaine hydrochloride are used by the otolaryngologist (ENT speciality) to produce topical anaesthesia of the nasal mucosa, the pharynx and the larynx. Cocaine is not only produces topical anaesthesia but also constricts blood vessels, shrinks the nasal mucosa and decreases bleeding.

Cocaine hydrochloride should not be used on large mucous membrane surfaces, such as the bladder; nor should it be used when denuded areas are present on mucous-membrane surfaces. Rapid absorption of large doses of cocaine is results, leading to serious reactions and death. A total of 150 mg of cocaine should never be exceeded during single administration.

Procaine Hydrochloride (Novocain). Novocain remains the most valuable local anaesthetic drug available for use in the ambulatory patient. Although introduced in 1905, it continues to be the yardstick for all other local anaesthetic drugs. Procaine has its shortcomings. It is not an effective topical anaesthetic when used in safe concentrations. It does not produce prolonged anaesthesia. Its action is relatively short (1/2 to 1 hour). However, this time period is more than adequate for the majority of out-patient surgical procedures. Procaine has survived the test of extensive clinical trial. It may be used for infiltration anaesthesia (0,5%), nerve block (1 to 1,5%) or plexus block. Onset of anaesthesia is relatively rapid. The effect of the drug is fully reversible. Sterile solutions of procaine are easily and conveniently prepared and are readily available commercially. Studies of many new anaesthetic agents have not produced a drug superior to procaine hydrochloride.

Tetracaine (Pontocaine Hydrochloride). Pontocaine hydrochloride is an excellent local anaesthetic drug, which may be used for topical, infiltration, nerve block or spinal anaesthesia. It possesses 10 to 15 times the potency of procaine, so that when employed for local anaesthesia one-tenth the estimated dose of procaine is used. This scaled down dose decreases the toxicity of the drug. Many investigators are of the opinion that Pontocaine is even less toxic than procaine. The real advantage of Pontocaine lies in its duration of action. When used for regional anaesthesia in combination with a vasoconstrictor drug, anaesthesia lasting from 4.5 - 5 hours may be obtained. However, unless a long-lasting local anaesthetic block is desired, a drug with effects of such long duration is actually a disadvantage in clinical practice. As a 0.5 - 2% solution, it is also being used more and more as a topical anaesthetic replacing cocaine. However, in this capacity, it has produced a number of fatal toxic reactions, which have retarded the more widespread acceptance of this agent. The maximum safe dose of pontocaine for any single administration is 100 mg by injection and 40 - 50 mg for topical application.

Lidocaine (Xylocaine). One of the more recent local anaesthetic drugs introduced to clinical anaesthesia is Xylocaine hydrochloride. It possesses all the advantages of procaine, and, in addition, is a good topical anaesthetic; its effects come on more quickly and its duration of action is longer. The toxicity of Xylocaine is greater than that of procaine. It may be substituted for procaine in those cases with a history of procaine sensitivity. This drug does not possess significant advantages over procaine to justify its complete adoption. The maximum safe dose is 0.5 g by injection and 200 to 250 mg for topical anaesthesia.

Dibucaine (Nupercaine Hydrochloride). Nupercaine hydrochloride is the longest lasting of the local anaesthetic drugs. Its duration of action is approximately 2,5 - 3 hours. The toxicity of Nupercaine is between 10 and 15 times greater than that of procaine. However, since the potency of the drug is 15 times greater than that of procaine, it may be used in greatly reduced dosage with excellent clinical effects. Concentrations of Nupercaine as dilute as 0.05% are sufficient to produce block of the sciatic nerve. Nupercaine is an excellent topical anaesthetic drug and is marketed as an ointment for treatment of various painful lesions of the skin. It is not used frequently for other types of regional anaesthesia unless a block of maximum duration is desired. Oily solutions of Nupercaine (0,5% Nupercaine with benzyl alcohol in almond oil) have been employed to produce long-lasting anaesthesia. The use of these solutions has generally been discarded because of the local tissue necrosis, which has resulted from their use.

Piperocaine (Metycaine Hydrochloride). Metycaine hydrochloride has been found to be useful in all types of regional anaesthetic procedures, including local infiltration, nerve and plexus block and spinal anaesthesia. It is also a good topical anaesthetic. While it is slightly more toxic than procaine when administered in equal dosage, its greater potency permits the use of less concentrated solutions. Metycaine has been widely used in obstetrics for caudal anaesthesia. Since Metycaine is not related to procaine chemically, it may be used in patients with suspected procaine sensitivity. 0,5 % Metycaine is used for infiltration anaesthesia, for nerve block: - from 1 to 1,5 % is employed. The total safe dose is 1 g.

Other Agents. Although many other local anaesthetic agents have been used clinically, none possesses such distinct advantages over those previously discussed to warrant its general acceptance and consideration. Individual drugs may be used according to the preference and the experience of the surgeon. One cannot be too cautious in the use and the acceptance of any new procaine substitute until its pharmacological action and toxicity have been thoroughly investigated.

Long-Lasting Anaesthetic Preparations

In an effort to obtain a local anaesthetic with long duration of action, which would be of value in the management of various types of pain syndromes, many preparations of drugs have been marketed. These usually consist of a solution of a local anaesthetic base in various vegetable oils, such as oil of sweet almonds, peanut oil or corn oil. In addition, other drugs with prolonged anaesthetic effects, such as benzyl alcohol, are added to the solution. Procaine, Nupercaine, Intracaine, Diothane and Benzocaine have been used most frequently as the anaesthetic base in these preparations. While in theory the concept of a long-lasting local anaesthetic preparation is good, in practice the use of these preparations has been most unreliable in relieving pain for prolonged periods. Serious local toxic changes at the site of injection have resulted from their use.

More recently, preparations have been introduced substituting a water-miscible and nontoxic organic solvent for the vegetable oils, which previously had been used as the vehicle for the local anaesthetics. The results obtained by the use of these preparations have been most unreliable. Local tissue reaction has been reported at the site of injection. Neuritis may be a complication following nerve block. The use of these preparations has now been abandoned. A great need still exists for a safe agent of this type.

Adjuncts to Local anaesthetics

Vasoconstrictors are added to solutions of local anaesthetic drugs,

1.       to prolong and intensify the anaesthesia;

2.       to permit the use of smaller concentrations of the local anaesthetic;

3.       to decrease the rate of absorption of the drug;

4.       to reduce the incidence of toxic reactions.

Epinephrine - Epinephrine is the most effective vasoconstrictor employed with local anaesthetics. The hydrochloride salt is most frequently used. It is marketed in 1 ml ampules containing 1 mg (1:1000) and in multiple dose vials containing 0,1% solution (1 mg/ml). When used in proper concentration, the injection of epinephrine causes local vasoconstriction at the site of injection. However, if larger amounts of epinephrine are used with the local anaesthesia solution, systemic toxic effects will be manifested. These reactions consist of tachycardia, palpitation, hypertension, headache, anxiety, restlessness, faintness, apprehension and tremor - all signs of excessive sympathetic activity. These reactions often are misinterpreted as being toxic manifestations of the local anaesthetic rather than the vasopressor agent. This is seen frequently in patients who had dental extractions performed under local anaesthesia. Higher concentrations of epinephrine are added to dental preparations of local anaesthetic drugs. If a patient gives a history of such a reaction, it must be ascertained whether the vasopressor drug or the local anaesthetic caused it. It is the belief of many that a reaction to epinephrine is far more common than a true local anaesthetic drug reaction.

The optimum concentration of epinephrine to be added to a local anaesthetic solution is 1:200000 in the final dilution. This amounts to 1 ml of 1:1000 solution (1 mg) of epinephrine for every 200 ml of solution. The use of a more concentrated solution of epinephrine (1:50000) does not further retard procaine absorption and leads only to a higher incidence of toxic vasopressor reactions. When adding epinephrine to a solution, it is best to use a 1 ml tuberculin syringe to obtain accurate amounts rather than a larger syringe, which frequently delivers more drugs than is necessary and produces overdosage of vasoconstrictor agent. Epinephrine should not be used in patients sensitive to the drug, in patients with thyrotoxicosis or in those patients, who have any type of occlusive vascular disease. It should be used with caution in patients with hypertensive cardiovascular disease or coronary artery disease. Many doctors do not advocate its use in blocking the fingers or the toes.

Cobefrin. Cobefrin is a vasoconstrictor drug less potent than epinephrine and producing fewer untoward reactions. It is about one fifth as potent as epinephrine and, therefore, is used in a final dilution of 1:40000. However, even with this concentration, the prolongation of action of the local anaesthetic is not as long as with epinephrine. Because, of the lower incidence of reactions produced by Cobefrin, it has been used frequently for the cardiac patients.

Hyaluronidase. Hyaluronidase, first described as the spreading factor of Duran-Reynals, is an enzyme capable of hydrolyzing hyaluronic acid, a viscous polysaccharide forming the interstitial connective substance. With the hydrolysis of this interstitial substance, the diffusion of injected solutions is greatly facilitated. Hyaluronidase has been used in conjunction with local anaesthesia in an effort to increase the number of successful blocks and to hasten the onset of anaesthesia. Various investigators have found that the addition of 150 turbidity reducing units of hyaluronidase to 30 ml solution:

1.       markedly shortens the onset of anaesthesia;

2.       decreases the duration of anaesthesia, especially if epinephrine is omitted;

3.       increases the incidence of toxic reactions to local anaesthetic agents and the vasoconstrictors;

4.       does not increase the percentage of successful blocks.

These effects are due to the more rapid absorption of the local anaesthetic solution due to greater and more rapid diffusion through the tissues. The drug is marketed in vials containing 150 T.R.U. (turbidity reducing units). Hyaluronidase may have a limited usefulness for the ambulatory patient.

A gist of local and regional anesthesia is the blockade of conducting of the painful impulses from the field of operation on the different levels.

Local anesthesia (LA) is a blockade in the zone of surgical intervention.

Regional anesthesia (RA) is the stopping of the painful impulsation proximal the field of operation.

The basic mediators, which are used for the local and regional anesthesia:

1.       local anesthetics (Novocain, etc.);

2.       narcotic analgesics (morphin, etc.);

3.       action of some physical factors (cold, etc).

The first local anesthetic was the solution of cocaine (Anrep V.K., 1979), which was used for 30 years without looking at its high toxicity.

Sklifasovsky was the first in the world, who operated with the solution of cocaine on the upper jaw.

S.P.Kolomnin, the professor of the chair of surgery of Kyiv University, widely used this anesthetic in the surgical practice. On November 6, 1886 he operated the woman with the ulcer of rectum (he used the solution of 5% cocaine). In 45 minutes the patient had the signs of poising by cocaine. The death was in two hours after the operation. Professor Kolomnin finished his life by suicide.

Professor Lukashewich (1886) from Kyiv tested the action of the solution of cocaine on himself and volunteers for conducting anesthesia on fingers (150 cases), made 36 surgical interventions in the cases whitlow. Today this anesthesia is famous as anesthesia after Lukashewich-Oberst (fig.1).

: Fig.1. Anesthesia by Lukashewich-Oberst

In 1905 Novocain was synthesized, less toxic anesthetic than cocaine, which considerably increased the adherents of local and regional anesthesia.

In dependence of the chemical structure the local anesthetics are divided into two groups:

-            complicated ethers of the aromatic acids with amino-spirits (novocain, dicain, cocaine);

-            amide of the ksilidini row (ksicaine, trymecaine, piromecaine, etc.).

Anesthetics of the second group have the stronger end longer action with the low toxicity than the mediators of the first group.

The mechanism of the action of the local anesthetics

The blockade of conducting of impulses on nervous fibers is explained from the position of the membrane theory. The molecules of local anesthetic, the solution of which is brought up to the nerve, in case of high lipoido-tropism are accumulated in the membranes of the nervous fibers. They disturb the function of the channels, through which in the usual conditions under the action of potential goes Na+ stream to the cell. In this case there is no depolarization of membrane and the movement through the fiber of the potential of action is impossible.

The most sensible to blockade are the thin unmyelinic fibers (vegetative). At first the painful and temperatures sensitiveness is blocked. Last is the conducting of excitation of impellent fiber. Renewing is taken place in the reverse order.

In the different anesthetics the time of blocking action is different. It depends on lipophilic of anesthetic its conservation and blood supply of the anesthetized field. Addition to the solutions of the local anesthetic vasopressors prolongs the blocking effect for decrease of blood supply of tissue.

The destiny of local anesthetics is different. Preparations of the first group are hydrolyzed for preparation of cholinesterase. The mechanism of biotransformation of preparations of the second group is definite insufficiently. Inactivation goes relatively slowly for the hepatic ferments.

Attacked to all kinds of local anesthetizing anesthetics in moderate quantity get into blood and caused general action in dependence of concentration. Taking into account this fact, it is necessary to keep only in recommended doses and concentrations, while using the local anesthetics. We must to take local anesthetics into account individual sensitiveness to them.

The periods of passing the local anesthesia:

1.       Introduction period of anesthetic solution includes the fulfillment anesthetic injections. The pain of the first injection diminishes making lemon pellicles, through which the anesthesia is conducting.

2.       The period of waiting the time, necessary for guaranteeing of action of the anesthetic solution on nervous outflows and nervous trunks. It depends on the kind of anesthesia, anesthetic and its concentration.

3.       Period of full anesthesia continues 1-2 hours. The painful sensitiveness at that time disappears as impellent function and reflexes can be well kept.

4.       Renewing period the sensitiveness is recovered, that is characterized by the pain in the field of surgical intervention and edema of soft tissues in the result of operation trauma.

Indexes for conducting of local anesthesia

1.       Ambulatory surgical operations;

2.       Small on volume surgical interventions;

3.       In weakened and exhausted patients;

4.       In old and extreme age people with diseases of cardiac-vascular and respiratory systems.

5.       In case of contra-indication to general anesthesia (narcosis).

Contra-indications for conducting of local anesthesia:

1.       Raised sensitiveness of organism to anesthetic;

2.       Mental affections;

3.       Sharp nervous excitement;

4.       Early child age (till 10 years);

5.       The urgent surgical interventions, connected with acute bleeding;

6.       Expressed fibrous changes of soft tissues;

7.       The surgical operations, which call for conducting of dirigible breathing;

8.       Long-term operations on body cavities;

9.       The refusal of the patient from local anesthesia.

Complications of local anesthesia:

Local: the damage by needle of anatomic formations or internal organs (nervous trunks, vessels, spinal cord, organs of pectoral or abdominal cavities), infectivity of soft tissues, bleeding, hematoma, inflammatory infiltrates, paresis, paralyses, peritonitis, etc.

General connected with overdoses of anesthetic or raised sensitiveness of organism to it.

1.       Light degree vasomotor discords (dizziness, pallor, cold sweat, general weakness, tachycardia, nausea).

2.       Middle degree stinging of central nervous system (impellent flustering, hallucinations, cramps, vomit).

3.       Heavy degree violation of activity of life important organs and systems (collapse, stop of breathing and cardiac activity).

Allergic reactions are nettle rash, Kvinkes swollen, bronchospasm, anaphylactic shock.

 

KINDS (TYPES) OF LOCAL AND REGIONAL ANESTHESIA

In dependence on method and admission level of the local anesthetic to nerves, which conduct painful impulses, the types of anesthesia are divided into:

-            Terminal;

-            Infiltrative;

-            Conduction;

-            Intraosseous;

-            Intravenous under tourniquet;

-            Epidural;

-            Spinal.

Terminal anesthesia is a simple and accessible method. It is realized by bringing the solution of anesthetic on mucous by the way of smearing, dispersion, dropping. The removal of the painful sensitiveness is realized only in the field of mucous. This method of anesthesia is only used in otorhinolaryngology, ophthalmology, endoscopes researches, etc.

For terminal anesthesia anesthetics of amides group are used: 2% solution of piromecaine, 5% solution of lidocaine hydrochloride (xycain), trymecaine, marcaine.

Infiltrative anesthesia is made layer by layer introduction of the solution of anesthetic on each next operation stage. Infiltration of tissues by 0,25% solution of Novocain for counting of high hydrostatic pressure spreads on the considerable extent of tissue washing the nervous fibers in them that provides an effective blockade of painful sensitiveness. The low concentration of the solution of anesthetic and running out at the moment of cutting the tissue, practically excludes an intoxication danger, without looking at introduction of its considerable volumes.

A.V. Vyshneysky is recommended such composing of solution: 5 gram natrium chloride, 5 gram potassium chloride, 0,125 gram calcium chloride, 100 ml distilled water, 2,5 gram Novocain, 2 ml 0,1% solution of adrenaline.

Novocaine Vyshnevskys blockade

Idea: the solution of anesthetics does not bring up immediately to nerve (classical variant), but the low concentration of Novocain solution is introduces in the big volumes into certain closed by fasciae spaces the painful sensitiveness is blocked more widely.

A covered blockade is reached by introduction of 0,25% solution of Novocain into the muscle cases (tight in filtrate) of the upper and lower finiteness on different levels. Anesthetic effect displays in 10 15 minutes as one of the components of anesthetic analgesia.

: Fig.2. Infiltration anesthesia. Intradermal bleb of local anesthesiaPresacral blockade: the anesthetic solution is put into operation between coccygeal bone and rectum on the middle line with going out on the front surface of sacrum bone. It is injected 150 200 ml 0,25% solution of Novocain. It is formed the infiltrate in the presacral field, which washed the nervous trunks that are going out through sacral holes.

As in case of covered blockade the partial underestimation of painful sensitiveness is reached.

Jugular vagosympathetic blockade: the solution of the anesthetic is put behind the chest-calculi nipple muscle higher or lower crossings of external jugular vein in the direction of the front surface of the jugular vertebrae. 40-60 ml 0,25% the solution of Novocain put into. The blockade is used in the hard traumas and operations on the thorax and its organs with the aim of underestimation of painful syndrome and prophylaxis of breathing violations and circulation of the blood.

Lumbar-paranephric blockade (block) anesthetic is put into behind the back form near the kidney fascia into paranephric fat. The testimony of the correct regulation of the needle is lack of the reverse flow of liquid from the needle cannula. 80 100 ml 0,25% solution of Novocain is put which reaches localizations of renal (nephric) and celiac plexus, abdominal nerves. It is set in case of violation of the function of kidneys, oliguria, anuria connected with the operative trauma, massive blood loss, dynamic intestinal obstruction, etc.

Conductive anesthesia method of regional analgesia, when the solution of the local anesthesia is put into the nervous trunk or interning proximally from the field of operation.

While fulfilled the conductive anesthesia one should to keep certain demands:

-            The solution of anesthetic must be put perineural, but not intraneural;

-            To give brining warning of antiseptic into vessel that controls by aspirator clamp;

-            When the solution of adrenaline is used as the component of the anesthetic solution, it is used in the concentration 1:200000 and is added immediately before blockade;

-            The recommended concentration of solution is kept severely (according to the pharmacology instruction) is not exceed a maximum dose;

-            The special needle 45-60 sharpened under corner is used for anesthesia.

Recommended anesthetics are: 1-2% solution of lidocaine hydrochloride (ksicaine), trymecaine, and marcaine. Rarely: 0,25% solution of dicaine, 1-2% solution of Novocain.

Addition of adrenalin solution prolongs anesthesia allows to get analgesic affect by lesser doses of analgesics.

By the help of conductive anesthesia is fulfilled:

-            Blockade of humeral plexus;

-            Blockade of middle nerve;

-            Blockade of elbow nerve;

-            Blockade of radial nerve;

-            Blockade of femoral nerve;

-            Blockade of sciatic nerve;

-            Blockade of the external thigh nerve;

-            Blockade of obturator nerve;

-            Blockade of intercostals nerves;

-            Blockade of paravertebral space;

-            Blockade of trigeminal nerve, etc.

 

Intraosseous and intravenous regional anesthesia

Fig.3. Technique of intraosseous regional anesthesia

Fig.4. Technique of intravenous regional anesthesia

The solution of the local anesthetic, which under plait brings into spongy bone matter, or intravenous, reaches capillaries and blocks sensitiveness turned out from the circulation of the blood the part of extremities.

After laying of tourniquet or elastic roller with the aim of turning out the circulation of the blood on the certain level of extremity, the anesthetic solution is put intraosseous into the condule of femoral, humeral, tibia bones, some bones of wrist and foot, which have a spongy structure. In intravenous anesthesia the analgesic solution is put into vein.

0,5% solution of Novocain, trymecaine, ksicaine is used as anesthetic, 50-70 ml use in the operations on the wrist and forearm and 60-80 ml in the operations on the foot and crus.

Epidural and spinal anesthesia is the method of conducting anesthesia, at which the analgesia with the help of local anesthetics is reached on the level of spinal radicles (rootlets).

The spinal anesthesia was started by M.Bir (1898), in Ukraine it was widely inculcated by professor B.Y.Frankenberg from Odessa. Epidural anesthesia approved by Pashe (1921).

Fig.5. Spinal anesthesia.

The principle of action of anesthetic in epidural anesthesia

The solution of anesthetic is deposits in space, between hard cerebral membrane and clear space covering an osseous spinal channel. Analgesic matters diffuse through the hard cerebral membrane and membrane of the spinal nerves into spinal fluid, then spreads through the intervertebral communications realizes paravertebral blockade of nerves. It should be remembered, that this action is followed by vasodilatation and lowering of the arterial pressure.

Before the fulfillment of epidural anesthesia, the premedication is made for warning the emotional effort of the patient and also for raising the effectiveness of anesthesia itself. The medical mediators are prescribed taking into account the state of the patient, the character of the operation. The most acceptable variant: on night Phenobarbital (0,1 - 0,15 g), diazepam (10mg). Diazepam (10-15mg), diprazin (25mg), atropine (0,5 mg), morphine (10 mg), phentanil (0,05 mg) is used intramuscularly, 30-40 minutes before the procedure.

The puncture of epidural space is made as a rule from the middle (between spinous processes or paramedial access), laterally on 1,5-2 cm, on the level of III IV lumbar vertebra.

During the fulfillment of the puncture it is necessary to remember that:

-            In adult the spinal cord is finished on the level of second lumbar vertebra;

-            The paracentetic needle goes over some obstacles: external and internal spinal connections (intercourses), yellow copula;

-            The width of epidural space is 3 mm, deeper the hard cerebral membrane is behind which the spinal channel is (spinal fluid!);

-            The control of the regulation of the needle in the epidural space is established by the presence of handing drop of solution, which sucks into the clear space of canula, if the needle is in the epidural space. Into space without special effort one can bring 2-3 ml of liquid.

The second control is back of treating of cerebral-spinal liquid through the needle after the revision of its passing by mandrin.

The special needle Tuokhi is used for catheterization of the epidural space, which has the special cut and hole, that catheter can reach the epidural space more comfortable.

2% solution of trymecaine, csicaine, 0,5% solution of marcaine, morphine (0,1 mg/kg) is used more often as the analgesic matter.

At first no more, than 4 ml of the general amount of anesthetic is used. It in the period of 5-7 minutes after the introduction of the trial dose the anesthesia does not tread, and then the residual dose is introduced. If trod (!), (the anesthetic reached the spinal fluid concentration of which into 10 times higher than that which is used for spinal anesthesia) it is necessary to stop further conducting of epidural analgesia.

The action of epidural block while using of 2% solution of trymecaine (20 ml) is in the period 40-60 minutes.

 

Complications of epidural anesthesia:

-            Vascular collapse by the reason of paralysis of vasoconstrictors, redistribution of blood. The infusion of plasma substitutes solutions is made before the introduction of the local analgesics to prevent this complication;

-            Total spinal block is arises in the case of puncture of hard cerebral membrane, when the anesthetic in high concentration is reached the spinal bulb. The collapse breathing paralysis is coming.

Contraindications for epidural anesthesia are:

-            Infection in the injection zone;

-            The necessity of the long-term operation;

-            Cure by anticoagulants;

-            Hypotension;

-            Shock;

-            Disease of central nervous system;

-            Pathologic changes of the spine (vertebral column).

Spinal anesthesia is the central form of the conducting analgesia, when the solution of the anesthetic is introduced into the spinal fluid and it has the immediate contact with the spinal nerves.

Demonstrations, premedication and the engineering elements of the spinal anesthesia on the first stage of its fulfillment are the same as in epidural anesthesia. The additional elements are the feeling of the failure of the needle after its penetration through the hard spinal membrane and apportionments of the cerebral-spinal fluid after moving away the mandrin, which testifies to the fact that the needle is in the subarachnoid space.

During the spinal anesthesia the puncture is made on the level of lumbar spine department: during the operations on the breasts organs, stomach between spinal processes L1 and L2 and during the operations on the organs of pelvis and lower extremities - between L3 and L4.

5% solution of Novocain 3 ml, solution of sovcaine 0,4-0,8 ml, 1% solution of trymecaine 1,5 ml are used more often anesthetic solution. The action term of anesthetics: Novocain and sovcaine about one hour all the rest to 1,5 hour.

Complications of the spinal anesthesia are very rare in case of it technically cored fulfillment. Besides of possible paralysis of sympathetic vasoconstrictors with hypotonia and development of hypovolemia, for blood deposition in the anesthetic fields can be:

-            Nausea, vomit during anesthesia (reflex from the blocking nerve), prophylactically add atropine solution in premedication;

-            Dizziness, the loss of consciousness, cramps as a result of hypoxia of cerebrum;

-            Violation of breathing by reason of paresis of intercostals muscles, diaphragms.

Remote complications:

-            Headache, insomnia;

-            Paresis of the derivative nerve and diplopia;

-            Aseptic leptomeningitis (pioarachnitis);

-            Adhesive arachnoiditis.

Contraindications for the spinal anesthesia are:

-            Infection in the injection zone;

-            The necessity of long-term operation;

-            During the cure of anticoagulants;

-            Hypotonia;

-            Shock;

-            Diseases of central nervous system;

-            Pathological changes of spine.

ARTIFICIAL HYPOTENSION

The attempts to operate patients with low blood tension are known quite well. It was described in ancient books that with hypotension patients underwent operations more easily. For this purpose the blood-letting was used, nowadays there are some medicines blocking the ganglions of vegetative nervous system: benzohexonium orphonat. Hypotension is especially important with neuro-surgical and vascular operations. These medicines can be used with other operations if arterial hypertension is observed. The contra-indications of artificial hypotension are coronary deficiency, loss of blood, glaucoma, and apoplectic stroke.

ARTIFICIAL HYPOTERMIA

Lowering of the temperature of the whole body or local center was used even in ancient times. Larrele and Pirogov observed lowering of painful perceptibility with hypotermia.

Bigelow applied this method in clinic. From the very beginning local hypotermia was used and then general hypotermia. Cooling of the patient begins after his having been brought under narcosis with the help of neuroleptics and muscular relaxants. A patient is put into cold water or ice-bags are put all round him. Nowadays, doctor use special hydrocostumes or let some cool liquid through the stomach. With operations on the cardio-vascular system cooling of blood is widely used, it is so-called extracarporal hypotermia. As a rule, the temperature is 30-33C (the surface hypotermia) or 20-25C (profound).

After the operation the patient is taken out of hypotermia by means of active warming (hot-water bottles, mattresses) or mass warm wrapping up.

This method is available with proper apparatus and good care of the patient.

ARTIFICIAL HYPERNATION

Any operation demands considerable reciprocal reaction of the organism, the increase of metabolism. It was noticed that some animals fall into winter sleep and their vital capacity is quite good with considerable decrease of metabolism. It was found that this condition of anabiosis could be used in clinic. Some mixtures consisting of neuroleptics, ganglioblockers can cause anabiosis. The combination of aminasine, diprasine, and lidol is used more often. The temperature decreases on 2-7C. According to this method, the reaction of the organism on the surgical trauma is more adequate.

People can be fight against pain not only by above-mentioned methods, which are connected with loss of consciousness. Painful perceptibility can be eliminated from the place of operation. Anren and then Aihiron proposed to use cocaine and novocaine and to put them into nervous tubes and plexus.

Different preparations were discovered, since then the specialists have been studying their toxic effects and working out the technique of their bringing into the organism.

 

INHALATION ANESTHESIA. NONINHALATION ANESTHESIA.

 

Narcosis.

Narcosis is aimed a temporary state of unconsciousness in the patient (narcotic sleep) and diminution or complete relief of sensitivity to pain (analgesia). General anaesthetics produce loss of consciousness and varying degrees of anaesthesia and muscular relaxation.

Anaesthesia is produced by progressively increasing the amount of the anaesthetic in the inspired air and thus in the blood and brain. Unconsciousness is one of its primary conditions. It results from the reversible reduction of the activity of the cortex and thus induces loss of consciousness. It can be produced by a variety of chemical agents that act on the brain.

Relaxation of sceletal muscles, essential for carrying out certain operations, may be achieved by deep anaesthesia but only for a short time since such narcosis is dangerous. It is replaced by a more superficial anaesthesia involving introduction of drugs which reduce muscle tension. Other factors which cause a drop in body temperature and blood pressure, etc., employed along with relaxants to produce a deeper analgesic effect of the anaesthetic and prevent undesirable side-effects (potentiated anaesthesia). When relaxants are administered such vital function as respiration is arrested deliberately and artifitial respiration is employed (controlled ventilation).

 

Preparing to the operation (preanaesthetic medication).

Anaesthetist must examine of patient before each operation. The tasks of examination are:

        General condition estimation;

        Peculiarities of anamnesis, connected with anaesthesia;

        Clinical and laboratory data estimation;

        Determination of degree of operational and narcosis risk;

        Method of anaesthesia selection;

        The character of premedication determination.

Premedication (preanaesthetic medication) is introduction of medicinal substances before operation for decreasing of intraoperation and postoperation complications frequency.

The main medicinal substances for premedication are:

        Opiates (barbiturates: pentobarbital, phenobarbital; benzodiazepines: nozepam, tazepam);

        Sedatives (diazepam, phenazepam);

        Neuroleptics (aminazine, droperidol);

        Antihistamines (Dimedrol, tavegil, suprasterol);

        Narcotic drug (promedol, morphine);

        Anticholinergic drug (atropine, methacin).

The main schemes of premedication are:

Before the urgent operation the narcotic drug and atropine (promedol 2% - 1,0, atropine 0,01 mg/kg) are introduced.

Before planned operation the usual scheme of premedication includes: at night opiates (phenobarbital 2 mg/kg) and tranquilizer (phenazepam 0,02mg/kg); in the morning (before 2-3 hours to the operation) diazepam 0,14 mg/kg; before 30 min. to the operation - promedol 2% - 1,0, atropine 0,01 mg/kg and Dimedrol 0,3 mg/kg are introduced.

 

Classification of narcosis.

1.     According factors which affecting on central nervous system;

        Pharmacodynamic (we have effect by pharmaceutical substances);

        Electronarcosis (electric field action);

        Hypnonarcosis (action by hypnosis).

2.     Accorging of medications introducing;

        Inhalation narcosis through respiratory ways the pharmaceutical substances are introduced. Aperture-mask, endotracheal and endobronchial narcosis are distinguished. In modern time usually the endotracheal narcosis is used.

        Noninhalation narcosis the preparation are introduced not through respiratory ways, but intravenously (mainly) or intramuscularly.

3.     According quontity of preparations:

        Mononarcosis the single preparation is used.

        Mixed narcosis some preparations at one time are used.

        Combined narcosis different narcotic substances during varios time of narcosis are used.

4.     According application on different phases of operation:

        Initial narcosis is short-term. For fast lulling to sleep of patient is used.

        Supportive (main) narcosis this anaesthesia is adjusted to all operation.

        Basis narcosis is superficial narcosis. The preparation of main narcosis and other anaesthetic drug for increasing of primary medicine dose are introduce.

 

Stages of anaesthesia.

Four stages of anaesthesia are distinguished.

1.                                                        Stage of analgesia. The first stage is characterized by partial unconsciousness and diminution of sensitivity to pain. Momentary operations may be performed during this period. Consciousness is gained quickly when the anaesthesia will be discontinued.

2.                                                        Stage of excitement. The second stage is extremely manifested in males, predominantly in drunkards. The possibility of concomitant vomiting makes it dangerous. The latter does not occur if the patient has been properly prepared for the anaesthesia, or when anaesthesia is produced by cyclopropane, nitrous oxide, or by intravenously injections of hexenaland pentothal.

3.                                                        Surgical stage. The third stage is divided into four planes. The first plane is characterized by superficial anaesthesia (the patient being unconscious), loss of sensitivity to pain, a good pulse, and arterial pressure of the same level as before anaesthesia. The pupils are narrowed; the reaction to light and the corneal reflex are retained. Involuntary rapid movements of the eyeballs (nystagmus) occur. The second plane develops as the anaesthesia deepens. Cessation of eyeball movement, constriction of the pupils and their sluggish reaction to light are characteristic of this period. Anaesthesia is conducted in these two planes when relaxants are imployed. The third plane which corresponds to deep anaesthesia is the threshold depth of anaesthesia. Its features are calm and deep respiration, a rhythmical and not frequent pulse, and the absence of the corneal reflex. The pupils are slightly dilatated and their reaction to light is weakened. Anaesthesia is conducted in this plane when relaxants are imployed. The fourth plane occurs only when an excess dose of anaesthetics is administered. During this plane the pupils dilate, respiration becomes shallow and diaphragmatic, and cyanosis develops frequently.

4.                                                        Agonal stage. The fourth stage is that respiratory paralysis and subsequent cardiac arrest. It is characterized by dilated pupils, which do not react to light, dryness of the cornea, disappearance of all reflexes, and complete muscular relaxation. Anaesthesia should never reach this stage. The period of recovery is also distinguished (it is of long duration only on operations performed over a long period of time). During this period anaesthesia becomes more superficial, the tongue tends to fall back, and excitation, vomiting, and respiratory disorders may occur. The patient must be under continuous observation during this period.