From Big Medical Encyclopedia

ANESTHESIA (a synonym an analgesia) — reversible elimination of painful sensitivity (by definition of the International Organization for Standardization). In the Russian and foreign literature still the synonym — anesthesia is used. However understand reversible loss of different types of sensitivity as anesthesia.

Distinguish local and general anesthesia.

Local The lake (local analgesia, anesthesia) — reversible (if the aim of a neurolysis is not pursued) and intentionally the caused loss of painful sensitivity in a certain part of a body.

The general The lake (the general analgesia, anesthesia) — the reversible loss of consciousness and all types of sensitivity intentionally caused with the therapeutic purposes during which reflexes are oppressed or disappear. It is usually reached by introduction of medicines. As a synonym of the general anesthesia quite often use the term an anesthesia — the reversible condition of oppression of the central nervous system caused by influence of physical or chemical means.

The local anesthesia is used for painless carrying out various surgical manipulations and treatment of pain syndromes. Local O. is reached by means of chemical (local anesthetics) and physical (cold, electric current, acupuncture) the methods interfering carrying out painful impulses on nerve fibril or increasing a threshold of painful sensitivity (see. Anesthesia local ). From local anesthetics most often use novocaine, Trimecainum, a xycain, Pyromecainum, Dicainum, sovkain (see. Anesthetics ).

The lake by means of cold (cryoanesthesia) is reached by local or regional cooling. For these purposes, except ice or the circulating cold water, use Aether chloratus (see). Quickly evaporating from the surface of skin, Aether chloratus causes its considerable cooling and O. of surface layers. From other fizich. methods the straightened sinusoidny currents of the low, periodically changing frequency (so-called diadynamic currents or Bernard's currents), high-frequency impulse currents (D'Arsonval's currents) have analgesic properties, and also galvanization (see) and electrophoresis (see). The analgesic effect manages to be gained also with the help acupuncture (see). Introduction of needles to certain reflexogenic points of a body causes and supports an analgesia (gipoalgeziya).

Local O. by means of pharmacological means is reached by spraying or greasing of mucous membranes of various bodies or administration of local anesthetics in fabrics and anatomic spaces (subarachnoidal, epidural). Distinguish the following types of a local analgesia: superficial (terminal), infiltration, nerve blocks (regional), juxtaspinal, blockade of neuroplexes, Epidural (according to the ISO 4135 international standard the term «Epidural» is more preferable than the term «peridural»), subarachnoidal (spinal), caudal.

The specified local O.'s types have reversible character and are widely applied in medicine, and also to treatment of chronic pain syndromes of various nature and localization (see. Novocainic blockade ).

In neurologic and oncological practice apply the ways directed to irreversible, constant O. Eto's achievement generally operational methods to fight against the intolerable pains which are not giving in to the reversible methods of local O. stated above (see. Neurotomy ), to-rye come down to interruption of nerve conduction paths at various levels of a nervous system from peripheral nerves to a cerebral cortex. Operations are carried out: 1) on the first neuron — section of sensory nerves and their roots; 2) on the second neuron — a section of spinotalamichesky ways in back, oblong either a mesencephalon, or destruction by pharmacological means of touch kernels of a visual hillock; 3) on the third neuron — a front talamotomiya, encephalotomy (it is applied seldom).

The general anesthesia is widely applied in all surgical specialties. The combined techniques of the general anesthesia at which use various pharmacological means of purposeful action prevail. So, for example, inhalation anesthetic is applied preferential to switching off of consciousness, the analgesia is reached by intravenous administration of strong analgetic means, neurovegetative braking — by means of neuroleptics, muscular relaxation — by means of muscle relaxants.

For the premedication which is an obligatory stage to performing the general anesthesia (see. Anaesthesia ), apply tranquilizers, antihistaminic, analgetic and the lever lytic drugs more often. In induction period (an introduction anesthesia) for switching off of consciousness mainly use an intravenous way of administration of drugs, apply an inhalation way of induction generally at children, it is frequent as a stage before a venipuncture.

In surgical practice the endotracheal anesthesia creating a possibility of appropriate control of the patient and allowing to influence actively a homeostasis is widely applied. The intubation of a trachea in these cases is carried out after introduction depolarizing or not - the depolarizing relaxants of short action. In the period of maintenance of anesthesia switching off of consciousness is provided most often with insufflation or inhalation of gas-narcotic mix of nitrous oxide with oxygen, sometimes added 0,3 — 0,5 about. % of Ftorotanum. On the course of operation enter analgetic and the neuroleptics which are not depolarizing Muscle relaxants carry out artificial ventilation of the lungs. Constantly exercise control of function of vitals and systems, fill blood loss), regulate indicators of acid-base equilibrium and water and electrolytic balance. In detail about the general O.'s techniques see. Anaesthesia .

Among the general O.'s methods often use neyroleptanalgeziya (see) on the basis of use of a neuroleptic of Droperidolum and an analgetic of fentanyl and various options of an ataralgeziya with use of an ata-raktik (tranquilizer) of Seduxenum and analgetics — fentanyl, pentazocine (lexirum), a dipidolor, Dec-stramoramida (palfium).

The tendency to wider use of not inhalation ways of the general O. Eto was outlined it is connected with the researches which revealed negative impact of inhalation anesthetics on personnel of operating rooms and also with the advent of the new effective intravenous anesthetics (e.g., Ketaminum) which are not rendering, as a rule, significant negative effect on functions of vitals. According to numerous researches the technique of drop administration of ketamine (500 mg) in combination with Seduxenum (20 mg) in 500 ml of 0,9% of solution of sodium chloride or 5% of solution of glucose with a speed of 1 — 2 mg/kg of 1 hour without use of inhalation anesthetics begins to be applied with success at the most various operations.

Among other not inhalation methods of the general anesthesia which are actively implemented in recent years in clinical practice it is necessary to mention the combined use of an electroanesthesia and elektroigloanal-geziya with various pharmacological drugs of anticonvulsant, sedative and analgetic action.

Anesthesia in the postoperative period is an obligatory component of a modern anesthesiology grant. It is necessary to emphasize that actions for O. directly during the first hours after operation are also important, as well as Premedication before operation. The pain syndrome arising directly after operation negatively influences functions of vitals and systems, especially breath, blood circulation, sympathoadrenal system, etc.

During the use of high doses of analgetic means (fentanyl) in the course of operation and existence of signs of oppression of independent breath it is more preferable to carry out the prolonged artificial ventilation of the lungs after operation, than to use antagonists of analgetics (Naloxonum, Nalorfinum). The last remove a residual analgesia, and patients have severe pains in an operational wound demanding administration of analgetic drugs. It is necessary to mention in this regard non-narcotic analgesic pentazocine (lexirum), to-ry, having the expressed soothing property, is an antagonist of morfinopodobny drugs. Administration of pentazocine at the end of operation removes effect of fentanyl and at the same time renders analgetic effect. For removal of postoperative pains use an igloanalgeziya; peridural anesthesia was widely adopted. During the carrying out the prolonged artificial ventilation of the lungs for an analgesia use nitrous oxide with oxygen (2:1; 1:1) and hydroxybutyrate of sodium. For anesthesia in the postoperative period widely use also narcotic (pantopon, Promedolum) and non-narcotic analgesics (analginum, pyramidon, pentazocine).

Features of anesthesia at children, patients of advanced and senile age

the Main method of an analgesia at children during the carrying out surgical interventions is the general Lake. Local O. is shown at children of advanced age at small interventions with obligatory premedication. Features of a children's organism dictate need of strict age differentiation at purpose of premedication. Doses of drugs shall correspond to age of the child strictly. Introduction to an anesthesia at children up to 5 years is carried out most often by a mask way, using for inhalation Ftorotanum, nitrous oxide, cyclopropane, etran. At children of more advanced age use as well neingalyatsioiny ways (intravenous, intramuscular, rectal). Feature of the period of maintenance of the general anesthesia at children is in tokhm that deepening of an anesthesia (during the carrying out an inhalation anesthesia) comes unlike adults quicker and at smaller concentration of anesthetic in the inhaled mix. And, the less child, the these specifics it is expressed more clearly.

At children it is necessary to avoid use of the anesthetics having the irritating influence on a mucous membrane of respiratory tracts. It is necessary to consider also big vulnerability of a mucous membrane of a trachea and at intubations (see) to use thermoplastic endotracheal tubes of the corresponding sizes. At newborns and children of chest age often use special tubes with the limiter interfering their introduction it is deep in a trachea (Cole's tube), at an intubation through the nasal courses and need of long and artificial ventilation of the lungs apply Eyre and Reece's special systems (see. Inhalation anesthesia ).

Achievements of anesthesiology allowed to solve generally a problem O. at difficult surgical interventions at patients of advanced and senile age. The physical age is not a contraindication to operation. However age changes of a senile organism significantly complicate maintaining anesthesia. During the carrying out operations use the general Lake more often. At the lower extremity operations apply also epidural anesthesia. Small surgical manipulations can be carried out with success in the conditions of different types of the local Lake. Specific feature of patients of advanced and senile age is their big sensitivity to medicines. It needs to be considered at all stages of anesthesia, beginning from premedication from which it is necessary to exclude means, strongly oppressing breath (morphine, pantopon) and to reduce doses of the used drugs by a half or one third. Introduction to an anesthesia at especially weakened patients can be carried out by inhalation of gas-narcotic mix of nitrous oxide with oxygen or administration of ketamine, more preferable in the intravenous drop way (0,5 — 1 mg/kg at 1 o'clock) in combination with small doses (5 — 10 mg) of Seduxenum. Doses of other drugs used in induction period and at maintenance of anesthesia including muscular relaxants, shall be also respectively reduced, and the anesthetics possessing cardiotoxic and a hepatotoxic action (e.g., Ftorotanum) are excluded. Existence of the expressed emphysema and a pneumosclerosis demands extremely careful use of spontaneous breath from the patient during an anesthesia. This technique is admissible at short-term operative measures (no more than 30 min.) on condition of free passability of respiratory tracts and periodic carrying out an assisted breast. At elderly it is not necessary to hurry with extubation of a trachea if there is the slightest doubt in adequacy of recovery of independent breath. In these cases it is reasonable to carry out in the postoperative period the prolonged artificial ventilation of the lungs within several hours.

Features of local and general anesthesia in field conditions — see. Anesthesia local , Anaesthesia .

Bibliyeogr.: Bunyatyan A. A., Ryabov G. A. and Manevich A. 3. Anesthesiology and resuscitation, M., 1977; And r of e r I. M. Neyrokhirurgiya, M., 1971; Manevich A. 3. Pediatric anesthesiology with elements of resuscitation and an intensive care, M., 1970; Martynov Yu. S. Neuropathology, M., 1974; Mashkovsky M. D. Pharmaceuticals, p.1 — 2, M., 1977; The Multivolume guide to surgery, under the editorship of B. V. Petrovsky, t. 10, page 402, M., 1964; The Guide to anesthesiology, under the editorship of T. M. Darbinyan, M., 1973; The Reference book on anesthesiology and resuscitation, under the editorship of V. P. Smolnikov, M., 1970.

A. A. Bunyatyan.