WO2009095611A2

WO2009095611A2 - Lightweight and compact cartridge for treating anaesthetic gases exhaled by a patient

Info

Publication number: WO2009095611A2
Application number: PCT/FR2009/050121
Authority: WO
Inventors: Gilles Cannet; Maxime Dori; Serge Moreau
Original assignee: L'air Liquide, Société Anonyme pour l'Étude et l'Exploitation des Procédés Georges Claude
Priority date: 2008-01-29
Filing date: 2009-01-28
Publication date: 2009-08-06
Also published as: FR2926730A1; WO2009095611A3; FR2926730B1

Abstract

A gas treatment cartridge (1) comprising an outer casing (2) containing at least one adsorbent material capable of adsorbing at least some of at least one anaesthetic compound of the nitrous oxide or xenon type present in a gas that is to be treated, the said casing comprising an end wall (4) at one of its ends and a lid (3) at the other of the ends. The lid (3) comprises a gas inlet orifice (11) via which the gas that is to be treated enters the casing (1), and at least one gas outlet orifice (12) via which the treated gas re-emerges from the casing (1). Also provided is an attachment device (5) that allows the cartridge (1) to be hooked onto a support, particularly a bar of a hospital bed or of a stretcher.

Description

Light and compact anesthetic gas treatment cartridge exhaled by a patient

The present invention relates to a reduced-autonomy cartridge containing an adsorbent for recovering the nitrous oxide (N ₂ O) or xenon (Xe) present in the gases exhaled by the patients, in particular in the treatment rooms of the patients. hospital buildings.

Nitrous oxide mixed with oxygen, for example in an equimolar 50% / 50% ratio, is used in the medical field as an analgesic which is administered to the patient by respiratory mask or the like. The protoxide is however not metabolized and exhaled by the patient in a volume mixture containing about 48% N ₂ O, 44% O ₂ , 4% CO ₂ and 4% water vapor.

Due to the configuration of the premises in which the care is performed and depending on the presence or absence of a ventilation system of the premises, the medical staff may be exposed to a greater or lesser inhalation of nitrous oxide. ambient, which is not necessarily desirable, especially if this inhalation of N ₂ O is important and / or frequent.

On the other hand, when the premises are equipped with a system of suction of gases to the outside, the nitrous oxide sucked up and then released into the atmosphere can have adverse effects from the point of view of the environment. In particular, it is a gas with a strong "greenhouse effect" and having a destructive action on the ozone layer.

In addition, the dispersion of medical nitrous oxide in a suction or exhaust air system is not simple because the destination of the evacuated gases must be well controlled to avoid further delay the problem solved locally and, moreover, the exhaled mixture is highly oxidizing and its transport requires an analysis of the risks generated by this characteristic and the use of compatible materials and convenient maintenance practices, excluding for example the lubrication of moving parts.

Moreover, xenon is also a gas used in the field of anesthesia and which has very interesting properties for this application. This use is generally done in the operating room but it can also be used in laboratories for research purposes. For reasons similar to those mentioned above, as well as for economic aspects related to the scarcity of xenon, it may be interesting, even desirable or necessary, to recover the xenon present in the gases exhaled by the patient.

As a result, it has been proposed to install a system for capturing patients' expired gases, in particular protoxide or xenon, through the use of an adsorbent adapted to the gas considered in the treatment rooms. to be recovered.

Thus, it has been proposed to use a zeolite of Faujasite type, for example a zeolite of the CaX, NaX, CaLSX or NaLSX type, to adsorb nitrous oxide, as well as CO ₂ and water vapor. lying in the expired gases. Other adsorbents, such as silica gels, activated carbons or zeolites effectively adsorb xenon.

These N ₂ O or xenon molecules present in the exhaled gases actually become selectively and reversibly attached to the pores of the adsorbent material, thus allowing them to be extracted from the gaseous mixture and sequestered before reprocessing. This reaction takes place under good conditions of kinetics and temperature.

To do this, the patient's exhalation tube is connected to a reservoir containing a zeolite or other adsorbent which passes oxygen but adsorbs nitrous oxide, xenon or any other therapeutic or anesthetic gas that is required. recover, thus avoiding that the molecules of this gas spread in the environment. When the adsorbent is saturated, it is reprocessed at the factory, by heating, resulting in the desorption of the adsorbed gases.

However, the problem that arises is that the adsorption capacity of the zeolites, brought back to the volumes expired by a patient during the duration of anesthesia or analgesia, lead to quite large volumes of adsorbent needed. As the density of the adsorbents is of the order of 0.7, the total mass of adsorbent is therefore also important. For example, to adsorb all the protoxide contained in a B5 bottle, that is to say 750 liters of gas or 2.5 liters of capacity (in water), it takes 10 to 15 kg of adsorbent .

This then gives rise to fairly strong constraints, particularly in terms of volume, weight and difficulty and / or frequency of handling by the nursing staff.

However, in the hospital environment, it may be necessary to move a patient from one place to another within a given building or in different buildings, or even a mobile unit type EMS to a building, or vice versa .

Therefore, it is necessary to be able to continuously recover the anesthetics exhaled by the patient, including during the time his transfer from one place to another, which is not thing easy, if not impossible, with current devices that are not suitable for frequent movements.

In view of this, a problem that arises is therefore to propose an adsorbent device dedicated to the trapping of volatile compounds present in the gases exhaled by the patients, in particular N ₂ O and xenon, which is adapted to these constraints. in particular that is adapted to short-term interventions or that can be used during a transfer of patient, and which is otherwise simple implementation by the nursing staff.

In other words, the invention aims to provide a device for recovering in situ, including nitrous oxide (N ₂ O) or xenon (Xe) found in the gas exhaled by patients, which is reduced space and well suited to easy implementation in a hospital or similar, especially in the care rooms of hospital buildings and for patients likely to be moved within said hospital buildings. A solution according to the invention is a gas treatment cartridge, in particular a light and compact cartridge, comprising an outer casing containing at least one adsorbent material able to adsorb at least a part of at least one anesthetic compound present in a gas to be treated. said anesthetic compound being selected from nitrous oxide and xenon, said shell having a bottom at one of its ends and a lid at the other end thereof, said lid comprising a gas inlet port through wherein the gas to be treated enters the casing, and further comprising at least one gas outlet port through which the treated gas exits the casing and an attachment device for attaching the cartridge to a carrier .

Depending on the case, the cartridge of the invention may comprise one or more of the following features:

- the inlet is located in the upper half of the container and the gas outlet is in the lower half of the container.

the outer envelope has a flattened shape.

- The adsorbent is arranged within a housing arranged in the casing, the internal volume of said housing containing the adsorbent being between 1 and 2 liters.

- The attachment device is shaped and dimensioned to allow to hang the cartridge to a bed bar or stretcher.

- The attachment device comprises an expansion of the lid wall or the outer envelope of circular or polygonal section. - The attachment device comprises an expansion of the wall of the lid or the outer casing of 2 to 4 cm of section.

- The attachment device is an expansion of the lid preferably formed integrally with the lid. - It comprises connecting means arranged at the gas inlet port adapted to and adapted to allow the connection of a gas supply pipe to said inlet port.

- The gas outlet port through which the treated gas exits the casing is arranged in the bottom or at the junction of the bottom and the casing. The invention also relates to an anesthetic gas distribution and gas recovery system exhaled by a patient comprising a cartridge according to the invention and a gas cylinder containing a gas or a gaseous mixture containing at least one anesthetic compound, said bottle of gas being connected to a respiratory interface for dispensing the anesthetic gas to a patient, via a first gas delivery conduit, so as to bring the delivered gas the gas cylinder to said respiratory interface and said respiratory interface being connected to the cartridge inlet through a second gas delivery conduit to bring the exhaled gases into said respiratory interface to the cartridge.

An embodiment according to the invention will now be explained in more detail with reference to the appended figures among which:

FIGS. 1 and 2 schematize a cartridge according to an embodiment of the present invention shown in operating state attached to a hospital bed bar, and

FIG. 3 schematizes a stack of cartridges according to FIG. 1. FIGS. 1 and 2 show a light cartridge 1 according to one embodiment of the present invention, which contains an adsorbent enabling the adsorption of a given volatile anesthetic compound to be removed, particularly N ₂ O or xenon in anesthetic or analgesic gas administered by inhalation to a patient.

Cartridge 1 is sized to contain sufficient adsorbent, for example zeolite, to adsorb all of the gaseous compound to be removed, particularly nitrous oxide or xenon, which would be exhaled by a patient for the duration of time. average of a surgical act or the like taking place in the place of use of the cartridge, for example for about 15 to 20 minutes, providing an internal volume for the adsorbent of 1 to 2 liters, for example of the order of 1.5 liter. In case of longer intervention, it will be sufficient to use several cartridges. For example, the dimensions of a cartridge according to the invention are a height and a width of one to several tens of centimeters, and a thickness of several centimeters. The fact that the cartridge 1 of the invention is flattened and compact is particularly interesting because it limits its size and therefore facilitates its use in hospital.

The nature of the adsorbent to be used depends on the gas to be treated and the level of purification of the desired gas. The choice will therefore be made on a case-by-case basis, in particular using empirical tests to test the effectiveness of a particular adsorbent available on the market. By way of example, as mentioned above, to adsorb N ₂ O, a faujasite-type adsorbent can be used, whereas for adsorbing xenon, a silica-gel type adsorbent, activated carbon or zeolite is chosen. Of course, it is also possible to use several different adsorbents which can be either arranged in successive layers in the cartridge 1, or mixed with each other thus forming a composite bed.

Preferably, the adsorption of the compounds on the adsorbent will be bottom up and desorption against the current adsorption, so from top to bottom. The gas can also be pretreated before adsorbing the N ₂ O, for example to remove all or part of the water vapor that it contains, that is to say to desaturate it in water.

More precisely, as shown in FIGS. 1 and 2, the cartridge 1 flattened and compacted according to the invention consists of an outer envelope 2 forming the peripheral body of the cartridge 1, a bottom 3 and a cover 4.

It also comprises an attachment device 5, such as an expansion of the wall of the lid or the outer casing 2, adapted and designed to allow a coupling of the cartridge 1 to a hospital bed bar or stretcher by means of said attachment device 5, that is to say that this attachment device is shaped and dimensioned to fit the contours of a hospital bed bar, which typically has a circular or polygonal section, including square , about 2 to 4 cm.

The outer shell 2 has an inner housing containing the adsorbent. It ensures the aesthetics, as well as the protection of the adsorbent in the inner housing and carries all useful information for use and identification in the form of labels or electronic chip.

The outer shell 2 may for example be made of polymer, while the inner housing containing the adsorbent may be made of a material better resistant to the physicochemical and temperature constraints generated by the adsorption of the anesthetic gas molecules, by in stainless steel. As shown in FIGS. 1 and 2, the connection on the cartridge 1 of the gas duct 15 connected to the breathing mask is done at a gas inlet orifice 11 arranged in the upper part of the cartridge 1, preferably through the lid 3, which is easily accessible, while the vent or outlet port 12 is located in the lower part of the cartridge 1, preferably through the bottom 4 or at the junction of the bottom 4 and the envelope 2.

In use, the cartridge 1 according to the invention is attached to a horizontal bar 10 of the bed or stretcher on which the patient is. A gas bottle containing an anesthetic gas or analgesic comprising, for example, N ₂ O or xenon, is connected to a breathing mask via a flexible conduit so as to convey the anesthetic gas to the mask feeding the patient's airways. The cartridge 1 according to the invention is also connected to the mask via another flexible conduit 15 which recovers the expired gases from the patient at the mask and routes them to the cartridge 1 where they are treated. The gas cylinder may be a conventional medical gas cylinder type B5 provided with a cowling or protective cap from covering and protecting the sensitive organs of the bottle, namely typically the valve or valve-regulator used to control the passage of gas to the outside of the bottle (flow and / or pressure), as well as its equipment, such as manometer, steering wheel or operating lever ... A bottle of this type is described for example in document EP-A-629812 and a pressure-reducing valve that can be used on such a bottle is described, for example, in document EP-A-747796.

The entry into the cartridge 1 of the gases exhaled by the patient is via the inlet orifice 11 and the discharge to the atmosphere gases freed of their anesthetic compounds, such as N ₂ O or xenon, is via one (or more) venting vent 12 is located in the lower zone of the cartridge 1; the anesthetic compounds being retained in the cartridge 1 by adsorbent therein. The purified gases being free of nitrous oxide or xenon can be evacuated simply in the room where the cartridge 1 is.

The inlet orifice 11 comprises duct connection means enabling the end of a duct 15 conveying the exhaled gases to be attached thereto from the respiratory mask, the intubation probe or any other similar device capable of recovering the gas exhaled by the patient. For example, the conduit connection means may be or include tapping or threading.

Figure 3 shows a stack of several cartridges 1 according to the invention on top of each other. In this embodiment, the clipping devices 5 and the Fund 4 cartridges are shaped so as to be able to snap into each other so as to allow compact storage of cartridges 1.

The cartridge 1 according to the invention can be used both in hospital buildings, such as hospitals or clinics, as in treatment rooms, especially in hospital buildings or in the office of a doctor, a dentist, a veterinarian or the like, or at home.

Claims

claims

1. Cartridge (1) for gas treatment comprising an outer casing (2) containing at least one adsorbent material capable of adsorbing at least a portion of at least one anesthetic compound present in a gas to be treated, said anesthetic compound being chosen from nitrous oxide and xenon, said envelope comprising a bottom (4) at one of its ends and a cover (3) at the other of its ends, said cover (3) comprising an inlet port of a gas (11) through which the gas to be treated enters the casing (1), and further comprising at least one gas outlet (12) through which the treated gas exits the casing (1) and an attachment device (5) for attaching the cartridge (1) to a support.

Cartridge according to claim 1, characterized in that the inlet (11) is located in the upper half of the container (1) and the gas outlet (12) is in the lower half of the container (1). container (1).

3. Cartridge according to claim 1, characterized in that the outer casing (2) has a flattened shape.

4. Cartridge according to one of the preceding claims, characterized in that the adsorbent is arranged in a housing arranged in the casing (2), the internal volume of said housing containing the adsorbent being between 1 and 2 liters.

5. Cartridge according to one of the preceding claims, characterized in that the hooking device (5) is shaped and dimensioned to allow to hang the cartridge (1) to a bar (10) bed or stretcher.

6. Cartridge according to one of the preceding claims, characterized in that the attachment device (5) comprises an expansion of the wall of the lid (3) or the outer casing (2) of circular or polygonal section.

7. Cartridge according to one of the preceding claims, characterized in that the attachment device (5) comprises an expansion of the wall of the lid (3) or the outer casing (2) of 2 to 4 cm section .

8. Cartridge according to one of the preceding claims, characterized in that the attachment device (5) is an expansion of the lid (2) formed integrally with said lid (3).

9. Cartridge according to one of the preceding claims, characterized in that it comprises connecting means (13) arranged at the inlet (11) of gas suitable for and designed to allow the connection of a pipe (15) for conveying gas to said inlet port (11).

10. Cartridge according to one of the preceding claims, characterized in that the gas outlet (12) through which the treated gas exits the casing (1) is arranged in the bottom (4) or at the junction the bottom (4) and the envelope (2).

Anesthetic gas distribution and gas recovery assembly exhaled by a patient comprising a cartridge (1) according to one of claims 1 to 10 and a gas cylinder containing a gas or a gaseous mixture containing at least one anesthetic compound. said gas cylinder being connected to a respiratory interface for dispensing the anesthetic gas to a patient via a first gas delivery conduit to bring the gas delivered to the gas cylinder to said respiratory interface, and said respiratory interface being connected to the inlet orifice (11) of the cartridge (1) via a second conduit (15) for conveying gas so as to bring the expired gases in said respiratory interface to the cartridge (1).