RU2183476C2 - Method and equipment for applying inhalation anesthesia - Google Patents

Abstract

FIELD: medicine; medical engineering. SUBSTANCE: method involves preparing anesthetic agent on the xenon base or anesthetic agent on the xenon base with fluorine-containing compounds. Anesthesia is carried out in partially reversible mode with gas mixtures being disinfected at in- and exhalation phase. CO₂ and H₂O are absorbed form the exhaled mixture with its being supplied back at the inhalation stage. Excessive portions are removed and the exhaled mixture is collected after anesthesia. Xenon recovery is carried out in removing excesses and after anesthesia by applying adsorption-desorption method, separating fluorine-containing and organic compounds on getters at their interaction temperatures under analytical xenon control with weighing and chromatography methods being applied. Recovered xenon is supplied to the stage of anesthetic agent preparation. Equipment has narcosis apparatus, removable cartridge filled with adsorbent agent being a xenon recovery complex ingredient and cryopump. The narcosis apparatus has unit for manufacturing anesthetic agent having compressed gas sources with flowmeter units and liquid fluorine-containing compounds evaporator unit, respirator unit having anesthetic composition analyzer, bactericide filters mounted on in- and exhalation lines, CO₂ and H₂O absorber units, exhaled gas mixture recovery line and inhalation line having two-way cock and protection valve. The xenon recovery complex has desorption vacuum pump, apparatus with getter filler, reservoir for collected recovered xenon and chromatograph device. Compressed xenon source, cartridge and reservoir are mounted on electronic scales. EFFECT: pure xenon production; excluded equipment disinfection means; multiple use of xenon with minimized losses. 3 cl, 1 dwg, 1 tbl

Description

 The invention relates to medicine, namely to anesthesiology, and can be used in experimental and clinical surgical practice using a promising anesthetic - xenon.

 Xenon, being a noble inert gas, easily penetrates the lungs, dissolves well in fats (oil-water solubility coefficient is 20), does not undergo biotransformation in the body and is excreted from the body for 3-4 minutes after cessation of supply. Xenon does not have a toxic effect on the mother and fetus, does not cause a cardiodepressive effect, does not affect the morphology and coagulation of the blood, does not change the neuroendocrine status, and provides reliable anesthetic protection.

 The present invention aims to expand the use of expensive and scarce xenon in medical practice by regenerating it for repeated use.

 A known method of inhalation anesthesia, including the preparation of anesthetic, conducting anesthesia in a partially reversible manner with the collection of exhaled anesthetic by adsorption.

 Equipment for implementing the known method consists of an anesthesia apparatus containing an anesthetic preparation unit, a breathing unit, and an adsorber for collecting exhaled anesthetic (filter of narcotic substances). [A. I. Trushin, V.M. Yurevich. Devices of inhalation anesthesia. - M .: Medicine, 1989, p. 54-55, 131-137].

The known technical solution does not provide the possibility of reuse of the anesthetic due to:
- lack of regeneration of anesthetic;
- lack of purification of the anesthetic from impurities;
- lack of analytical control of the anesthetic used during surgery.

 Also known is a method of inhalation anesthesia and equipment for its implementation, which are the closest in technical essence and the achieved result to the claimed invention.

A known method of anesthesia involves the preparation of an anesthetic based on xenon or an anesthetic based on xenon with the addition of fluorine-containing compounds, anesthesia according to a partially reversible type with disinfection of gaseous mixtures at the phases of inhalation and exhalation, absorption from an exhaled mixture of CO ₂ and H ₂ O and fluorine-containing compounds, returning it to the inspiratory phase with the possibility of removing excess and collecting the exhaled mixture after anesthesia. Moreover, the exhaled mixture is not subjected to regeneration for repeated use. Analytical control of the known method includes mainly determining the quantitative characteristics of gas mixtures, for example, flow rate and concentrations, during anesthesia.

Equipment for implementing the described method contains an anesthesia apparatus, a container for collecting exhaled mixture and a device for forced gas supply. The anesthetic apparatus consists of an anesthetic preparation unit, including compressed gas sources with flow meters and an evaporator of liquid fluorine-containing compounds, and a breathing unit, including an anesthetic composition analyzer and bactericidal filters mounted on the inhale and exhale lines, a CO ₂ and N ₂ O absorber, an exhaled return line mixes into the inspiration line equipped with a two-way valve and safety valve. Moreover, the container for collecting the exhaled mixture is a cylinder, a compressor is installed as a device for forced gas supply, an adsorber for separating fluorine-containing compounds is also placed after the СО ₂ and Н ₂ О absorber. Anesthesia apparatus, in addition, is equipped with gas analyzers that determine the concentration of xenon, the presence of N ₂ and CO _{2 in it} . [US patent 4905685, IPC A 61 M 16/00, NKI 128/203, decl. 180968 from 04/13/1988, publ. 03/06/1990, "Equipment for inhalation anesthesia"].

The described method and equipment for its implementation do not allow to regenerate and reuse xenon for operations on different patients due to the lack of appropriate procedures and devices, namely:
- there is no extraction of xenon from the collected exhaled mixture;
- there is no purification of xenon from microimpurities;
- there is no analytical control of the collected xenon for the presence of trace elements.

 The present invention is to provide a method of inhalation anesthesia and equipment for its implementation, allowing to regenerate and reuse purified xenon for operations on different patients while minimizing its losses.

The problem is solved in that in the known method of inhalation anesthesia, including the preparation of anesthetic based on xenon or anesthetic based on xenon with the addition of fluorine-containing compounds, conducting anesthesia according to a partially reversible type with disinfection of gaseous mixtures at the phases of inhalation and exhalation, absorption from the exhaled mixture ₂ , H ₂ O and fluorine-containing compounds, returning it to the inspiratory phase with the possibility of removing excess and collecting the exhaled mixture after anesthesia, according to the invention, while removing the excess and After anesthesia, xenon is regenerated by adsorption-desorption, separation of fluorine-containing and organic compounds on getters at the temperature of their interaction with analytical control of xenon, for example, by weighing and chromatography methods, and the subsequent return of regenerated xenon to the stage of preparation of the anesthetic.

In the known equipment for inhalation anesthesia containing an anesthesia apparatus, a reservoir for collecting exhaled mixtures and a device for forced gas supply, the anesthesia apparatus consists of an anesthetic preparation unit including compressed gas sources with flow meters and an evaporator of liquid fluorine-containing compounds, and a breathing unit including an analyzer bactericidal composition anesthetics and filters mounted on the inspiratory and expiratory lines absorber CO ₂ and H ₂ O, return line exhaled mixture in the inspiratory line, provided with equipped with a two-way valve and a safety valve, according to the invention, a replaceable cartridge filled with an adsorbent and included in the xenon regeneration complex, which also includes a stripper, vacuum pump, apparatus with getter filler, for example, with sponge titanium, was used as a device for forced gas supply - a cryopump and a cylinder for collecting regenerated xenon, and the compressed xenon source, cartridge and cylinder are mounted on an electronic balance, and in the regeneration complex, in addition, n, for example, a chromatograph.

The implementation of the proposed method of anesthesia using the proposed equipment in comparison with the prototype [see US patent 4905685] provides:
- the possibility of regeneration of xenon;
- obtaining pure xenon without impurities;
- repeated use of xenon (return of the cylinder with clean regenerated xenon to the stage of preparation of the anesthetic);
- cheaper anesthesia;
- minimization of xenon losses.

 Analysis of the known technical solutions allows us to conclude that the claimed invention is not known from the level of the studied technology, which indicates its compliance with the criterion of "novelty."

 The essence of the claimed invention for a specialist does not follow explicitly from the prior art, which allows us to conclude that it meets the criterion of "inventive step".

 The possibility of anesthesia in the conditions of the proposed method using the proposed equipment, assembled from predominantly commercially available domestic devices and devices, indicates that the invention meets the criterion of "industrial applicability".

 The inventive method of inhalation anesthesia and equipment for its implementation have been clinically tested in the departments of anesthesiology and intensive care at the Ural State Medical Academy, city hospital 3 (Tomsk) and hospital 3 (Volynska) of the Medical Center UD President of the Russian Federation (Moscow).

 The drawing shows a diagram of equipment for implementing the inventive method of inhalation anesthesia.

Designations in the drawing:
1 - anesthesia apparatus
2 - replaceable cartridge with adsorbent
3 - cryopump
4 - anesthetic preparation unit
5 - source of compressed xenon (cylinder)
6 - source of compressed oxygen (cylinder)
7 - evaporator of liquid fluorine-containing compounds
8 - flowmeters
9 - breathing unit
10 - breathing bag
11 - anesthetic composition analyzer
12 - inspiratory and expiratory valves
13 - bactericidal filters
14 - mask or tube of the patient
15 - line of inspiration
16 - expiration line
17 - absorber CO ₂ and H ₂ O
18 - line return the exhaled mixture
19 - two-way valve
20 - safety valve
21 - regeneration complex
22 - stripper
23 - vacuum pump
24 - apparatus with getter filler
25 - cylinder with regenerated xenon
26 - electronic scales
27 - chromatograph
Equipment for inhalation anesthesia (see diagram in the drawing) consists of an anesthesia apparatus 1 - Polynarcon 2P, a replaceable cartridge 2 with an adsorbent, for example, activated carbon, and a cryopump 3. Anesthesia apparatus 1 contains an anesthetic preparation unit 4 and a breathing unit 9 The anesthetic preparation unit 4 includes a compressed xenon 5 source mounted on an electronic balance 26, a compressed oxygen source 6 with corresponding flow meters 8, and an evaporator of liquid fluorine-containing compounds 7. The breathing unit contains a breathing bag to 10, the composition analyzer 11 anesthetics, bactericides filters 13, a mask (or a tube) of a patient 14, an absorber of CO ₂ and H ₂ O 17, the inspiratory line 15, expiratory line 16, return line 18 in exhaled mixture inspiratory line 15. Line 18 is provided with two-way valve 19 (solid line - the valve is closed, the dotted line - the valve is open) and safety valve 20. All elements of the anesthesia apparatus are interconnected by tubular communications with the necessary valves.

 The regeneration complex 21 consists of a replaceable cartridge 2 mounted on an electronic balance 26, a stripper 22 (which is a thermally insulated body with a socket for accommodating a replaceable cartridge), a vacuum pump 23, a device with getter filler 24 (getter filler - sponge titanium), cryopump 3 , chromatograph 27 and a cylinder with regenerated xenon 25 mounted on an electronic balance 26.

 The xenon regeneration complex 21 can be placed directly in the operating room or in a separate room remote from it. The replaceable cartridge 2 is freely disconnected from the communication lines with the anesthesia apparatus 1 and moves (transferred manually or in another way) to the stripper 22.

 Example 1. The implementation of inhalation anesthesia using anesthetic based on xenon.

 Before anesthesia was performed, the anesthesia apparatus and patient's lungs were denitrogenated - nitrogen was displaced by oxygen, by supplying the latter from a compressed oxygen source 6 using a two-way valve 19 (valve position is open) with further discharge of oxygen through cartridge 2 into the atmosphere.

 To prepare an anesthetic based on xenon, oxygen (300 ml / min) and xenon (1.16 l / min) flows were established from sources of compressed gases 5 and 6, which were mixed on the inhalation line of anesthesia apparatus 1 (valve position 19 is open).

After washing the breathing unit 9 with the mixture obtained, the xenon consumption was reduced to 600 ml / min and a surgical operation was performed using anesthesia of a partially reversible type (the position of the valve 19 is closed). In this case, the mixture circulating in the breathing unit 9 was disinfected during inhalation and exhalation using bactericidal filters 13, it was cleaned of CO ₂ and Н ₂ O in the absorber 17, and its excess was discharged through a safety valve 20 into a replaceable cartridge 2, in which xenon adsorption took place activated carbon (start of xenon regeneration).

 After the operation was completed, the exhaled mixture was collected in removable cartridge 2 (valve position 19 is open) by displacing it with oxygen from source 6 (xenon adsorption in cartridge 2 ends).

Then, xenon regeneration was continued, having previously evacuated the entire regeneration complex using a vacuum pump 23. The replacement cartridge 2 was manually transferred to stripper 22, which was gradually heated to a temperature of at least 180 ^° C, while xenon was desorbed. The xenon released from stripper 22 using a cryopump 3 was sent to an apparatus with getter filler (sponge titanium) 24, in which exhaled organic compounds (e.g. acetone, methane, etc.) were separated at a temperature of their interaction of 900 ^o C. After that, regenerated xenon using a cryopump 3 was pumped into a cylinder 25, completing the regeneration.

 The presence of trace elements in the regenerated xenon was determined using a chromatograph 27.

 Regenerated pure xenon in a cylinder 25 was returned to the preparation stage, at which it served as a source of compressed xenon 5. Cartridge 2 was removed from stripper 22 and reattached to anesthesia apparatus 1.

 The weight of all containers containing xenon (source of compressed xenon 5, cartridge 2 and cylinder 25) was controlled using electronic scales 26.

 Under conditions similar to example 1, inhalation anesthesia was performed using a low-flow anesthesia apparatus (low-flow) using an xenon-based anesthetic with the addition of fluorine-containing compounds (fluoroethane with a concentration of 2.0 ± 0.5 vol.% In the respiratory block) in the example 2. Moreover, the separation of fluorine-containing compounds from xenon was carried out in apparatus 24.

 The research results are shown in the table.

As can be seen from the above examples and table data, the use of the claimed "Method of inhalation anesthesia and equipment for its implementation" in comparison with the known method and equipment taken as a prototype [see US patent 4905685], provides the following technical and socially useful advantages:
- xenon regeneration;
- obtaining pure xenon without impurities;
- elimination of the need for disinfection and cleaning of cylinders and replaceable cartridge;
- the repeated use of xenon;
- minimization of xenon losses;
- the possibility of using one regeneration complex for servicing several clinics.

Claims (3)

1. A method of inhalation anesthesia, including the preparation of an anesthetic based on xenon or anesthetic based on xenon with the addition of fluorine-containing compounds, anesthesia according to a partially reversible type with disinfection of gaseous mixtures at the phases of inhalation and exhalation, absorption from an exhaled mixture of CO ₂ , H ₂ O and fluorine-containing compounds, returning the mixture to the inspiratory phase with the possibility of removing excess and collecting the exhaled mixture after anesthesia, characterized in that when removing the excess and after anesthesia, xeno is regenerated on the basis of its adsorption-desorption, separation of fluorine-containing and organic compounds on getters at the temperature of their interaction with analytical control of xenon by weighing and chromatography methods and the subsequent return of regenerated xenon to the stage of preparation of the anesthetic. 2. Equipment for inhalation anesthesia, comprising an anesthesia apparatus, a container for collecting exhaled mixture and a device for forced gas supply, the anesthesia apparatus consisting of an anesthetic preparation unit, including compressed gas sources with flow meters and an evaporator of liquid fluorine-containing compounds, and a breathing unit, including analyzer anesthetics, antibacterial filters, mounted on the inspiratory and expiratory lines absorber CO ₂ and H ₂ O, return line exhaled mixture in the inspiratory line, supplies two-way valve and safety valve, characterized in that the container used is a replaceable cartridge filled with adsorbent and included in the xenon regeneration complex, which also includes a stripper, vacuum pump, getter-filled apparatus, and a cryopump as a device for forced gas supply , and a cylinder for collecting regenerated xenon, the compressed xenon source, cartridge and cylinder mounted on an electronic balance, and the chromatograph is also placed in the regeneration complex.  3. Equipment for inhalation anesthesia under item 2, characterized in that sponge titanium is used as a getter filler.

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