FR2988005A1 - Artificial respiration device for resuscitation of cardiac arrest person, has upstream and downstream recesses for directing upstream and downstream jets of respiratory gas in direction of interior of main channel, respectively - Google Patents

Abstract

The device has an auxiliary upstream channel (8) including a proximal end (8p) connected with a respiratory gas source (S) to insufflate an upstream jet (F1) of respiratory gas towards a respiratory system of a patient. An auxiliary downstream channel (17) includes a distal end (17d) between a distal end (8d) of the upstream channel and a distal end (3) of a main channel (5) to insufflate a downstream jet (F2) of respiratory gas towards a proximal end (2) of the main channel. Upstream and downstream recesses (13, 22) direct the jets of gas in the direction of the interior of the main channel. An independent claim is also included for an artificial respiration system.

Description

The present invention relates to a device and an artificial respiration system that can be used, in particular, during the resuscitation of persons in a state of cardiac arrest. It is known that, in an attempt to resuscitate a person in a state of cardiac arrest, the person's rib cage is exercised with alternating rhythmic compressions and decompressions tending to re-establish the exhalation and inspiration movements, as well as blood flow. In addition, there is already known from EP2117629 an artificial respiration device for people in a state of cardiac arrest and being resuscitated by compressions and alternating decompressions of their rib cage. Such a device comprises: a tube which forms a main channel and which is intended to be connected by its distal end to a respiratory tract of a patient so that said main channel connects, externally, the respiratory system of said patient; at least one upstream auxiliary channel capable of being connected, at its proximal end, to a source of respiratory gas in order to be able to inject a jet of such respiratory gas towards said respiratory system and whose distal end opens into said channel; main ; and means for deflecting said stream of breathing gas towards the interior of said main channel provided between the distal end of said upstream auxiliary channel and that of the main channel. Subsequently, the upstream and downstream are defined with reference to the flow of a gas in the main channel from the proximal end of the latter towards its distal end.

Thus, the patient is continuously ventilated by said upstream jets of respiratory gas, the latter favoring the resumption of inspiration and blood circulation. However, the Applicant has noted that said breathing gas, continuously introduced into the lungs of the person in the cardiac arrest state, generates in them, at the end of a compression and at the beginning of the subsequent decompression, a positive residual pressure, which is maintained during part of said decompression, before disappearing and being replaced by a negative pressure generated by the decompression. Such positive residual pressure, on the one hand, forms an obstacle to the intake of outside air through said tube and, on the other hand, is maintained by said sucked outside air. As a result, during a significant portion of each decompression, the lungs of said person suck poorly outside air and blood circulation (including venous return) is not satisfactorily provided at the ends (head, arm, legs) of said person.

The present invention aims to overcome this disadvantage. To this end, according to the invention, the artificial respiration device, in particular intended for the resuscitation of a person in cardiac arrest, comprising: a tube forming a main channel which is intended to be connected by its distal end to a respiratory tract of a patient for said main canal to connect, externally, the respiratory system of said patient; at least one upstream auxiliary channel capable of being connected, at its proximal end, to a source of breathing gas so as to be able to continuously blow an upstream jet of such respiratory gas towards said respiratory system and whose distal end opens into said breathing gas main channel; and - upstream deflection means of said upstream flow of respiratory gas towards the interior of said main channel arranged between the distal end of the latter and the distal end of said upstream auxiliary channel, is remarkable in that it comprises in in addition: - at least one downstream auxiliary channel which is capable of supplying breathing gas and whose distal end opens into said main channel, between the distal end of said upstream auxiliary channel and the distal end of said main channel, for being able to blow a downstream jet of such respiratory gas into the latter towards the proximal end of the main channel; and - downstream deflection means of said downstream stream of respiratory gas towards the interior of said main channel, arranged between the distal end of said downstream auxiliary channel and the distal end of said upstream auxiliary channel. Thus, thanks to the invention, the direction of flow of the upstream jet of breathing gas escaping from the upstream auxiliary channel is opposite to the direction of flow of the downstream jet of respiratory gas from the downstream auxiliary channel: one is directed towards the distal end of the main canal (ie towards the patient's respiratory system), the other towards the distal end thereof (ie outward). In this way, during a decompression of the chest of a person being resuscitated, the outside air sucked is braked by the breathing gas leaving the auxiliary channel downstream, allowing a gradual and controlled aspiration of the outside air towards the lungs of the person. The braking obtained is of decreasing intensity during the decompression. This leads to the disappearance, at the beginning of the decompression, of the positive residual pressure due to the upstream stream of respiratory gas from the upstream auxiliary channel, during the gradual entry of the sucked outside air. Positive residual pressure is no longer an obstacle to the aspiration of outside air and the blood circulation of the person in cardiac arrest. Consequently, the variation in intrathoracic pressure in the lungs between compression and decompression, obtained according to the invention, is extended in comparison with the variations in intrathoracic pressure observed in persons undergoing resuscitation equipped with a known artificial respiration device as previously described. The gas exchange surface is thus increased and the venous return improved.

During a compression of the chest of the person being resuscitated, the upstream jet of breathing gas slows the airflow from the lungs, which causes an increase in pressure (positive pressure) inside the lungs. , air chased said lungs escaping freely but more difficult.

In addition, the braking of outside air sucked according to the invention is obtained - thanks to the (x) jet (s) of respiratory gas contrary to that (those) which feeds (s) the respiratory system of the patient - without implementation of one or more mobile elements housed in the main channel, which simplifies the manufacture of the artificial respiration device and increases its reliability. In addition, the device of the invention, once connected to the respiratory system of the person in cardiac arrest state, forms an open system which prevents the occurrence of overpressure in the stomach (that is, all "Inflating the stomach") and allowing a continuous supply of breathing gas while applying, without interruption, compressions and decompressions alternately on the chest of said person. It reduces the risk of trauma to the respiratory system of the latter, while improving hemodynamics. The present invention also relates to an artificial respiration system, in particular intended for the resuscitation of a person in cardiac arrest, comprising an artificial respiration device of the type described previously. According to the invention, said system comprises means for regulating the flow rate of breathing gas flowing, on the one hand, in the upstream auxiliary channel and, on the other hand, in the downstream auxiliary channel as a function of the compressions and decompressions exerted on the the ribcage of the patient in cardiac arrest.

Preferably, the adjustment means comprise means for detecting compression and decompression of the patient's rib cage, so that: - when compression is detected by the detection means, the flow rate of the Respiratory gas from the upstream auxiliary channel is maintained, by the adjustment means, greater than the respiratory gas flow rate of the downstream auxiliary channel; and when decompression is detected by the detection means, the respiratory gas flow rate of the upstream auxiliary channel is maintained by the adjustment means lower than the respiratory gas flow rate of the downstream auxiliary channel.

Thus, the adjustment means allows a precise adjustment of the flow of respiratory gas circulating in the upstream and downstream auxiliary channels as a function of the pressure in the chest of the patient being resuscitated, which allows, in particular, an effective control of the the intensity of the braking exerted on the outside air sucked during decompression and on the air expelled from the lungs of the patient during a compression. In addition, the detection means may be in the form of: at least one force sensor intended to be applied to the thoracic cavity of the patient in a cardiac arrest state; and / or at least one pressure sensor capable of measuring the pressure inside the main channel in the vicinity of its downstream end. In addition, the system of the invention may comprise means for diluting (for example with the aid of outside air) respiratory gas coming from at least one of the upstream and downstream auxiliary channels, for example inserted between the distal ends. of these. These dilution means are advantageously adjustable, to allow a precise adjustment of the dilution. Thus, the breathable gas supplying the upstream auxiliary channel (s) (which is most often pure oxygen from an oxygen cylinder) can be diluted, which allows it to be better tolerated by patients whose The body is accustomed to high levels of carbon dioxide in the blood and can not withstand pure oxygen ventilation. Furthermore, said tube may be formed of a single piece comprising said downstream and upstream auxiliary channels.

In a variant, said tube, forming said main channel, may comprise at least three distinct tube sections intended to be connected together, among which: an upstream section which carries said upstream auxiliary channel and said upstream deflection means; and an intermediate section, intended to be attached to the upstream section, which carries said downstream auxiliary channel and said downstream deflection means.

In the latter case, said device may comprise means for connecting together said sections. Furthermore, said system of the invention preferably comprises a plurality of upstream auxiliary channels and a plurality of downstream auxiliary channels. In addition, to ensure the safety of the patient, the system may comprise at least one exhaust valve, preferably calibrated, able to prevent the occurrence of overpressure in the main channel. More preferably, said adjusting means are advantageously remote from said artificial respiration device, so as to be able to remotely adjust the flow of breathing gas circulating in the upstream and downstream auxiliary channels. The figures of the appended drawing will make it clear how the invention can be realized. In these figures, identical references denote like elements. Figure 1 is a partial schematic view, in enlarged axial section, of an embodiment of the artificial respiration system of the present invention. FIGS. 2 and 3 are transverse diagrammatic sections, respectively along the lines II - II and FIG. 1. FIG. 1 shows, schematically and on a large scale, only the proximal portions 2 and the distal portions 3d. an embodiment of the artificial respiration system 1 according to the present invention. This embodiment may constitute, for example, an oro-nasal endotracheal tube with or without a balloon, a pediatric endotracheal tube, a gas monitoring probe, an endobronchial probe, an anatomical intubation probe for a child, a neonatal Cole probe, a Gedel cannula probe, a nasal oxygen therapy probe, etc. The system 1 comprises a tube 4, flexible or preformed (to adapt to the morphology of the patient) delimiting a main channel 5 having a proximal orifice 6 and a distal orifice 7, respectively at the ends of said tube 4.

Thus, the main channel 5 is capable of ensuring the passage between the proximal and distal ports 6 6, one of which (distal orifice 7) is intended to be inside the respiratory tract of a patient and the another (proximal orifice 6) is intended to be outside said patient. This proximal orifice 6 can open into the open air and, in this case, the patient can inhale fresh air and exhale stale air through the main channel 5. It is also possible to connect the orifice 6 to a a source of breathable gas under pressure and providing a system of unidirectional valves, for the patient to breathe the source breathable gas through said main channel 5 and exhale the stale gas to the open air, also through this main channel 5. The diameter of the main channel 5 is of the order of a few millimeters. Satisfactory tests were carried out with diameters of 3 mm, 7 mm, 8 mm and 12 mm. Furthermore, in the thickness of the wall of the tube 4, there are formed upstream auxiliary channels 8, extending along an upstream portion of the main channel 5 and intended to be connected to a source of breathable gas under pressure S for example a medical bottle of pure oxygen under pressure or the like. The connection to the source of breathable gas can be achieved by means of a ring 9, sealingly surrounding the tube 4 and delimiting a sealed annular chamber 10 around said tube 4. The upstream auxiliary channels 8 are put in communication with the annular chamber 10, at their proximal end 8p, thanks to local tearing 11 of the wall of the tube 4. The chamber 10 is connected to said source of breathable gas S by a supply duct 12, itself connected to the source S via a link L1. The upstream auxiliary channels 8 have a diameter smaller than that of the main channel 5. The diameter of the upstream auxiliary channels 8 is preferably less than 1 mm and, advantageously, it is of the order of 5 to 800 microns. On the distal side, the upstream auxiliary channels 8 open into an upstream recess 13 of the inner wall 14 of the tube 4. The upstream recess 13 is annular and centered on the axis 15 of said tube 4. It comprises a face 13a, substantially transverse or slightly inclined so as to constitute an upstream flare of the main channel 5, into which said upstream auxiliary channels 8 open through their orifices 16, as well as a face 13b following the face 13a and converging in the direction of the axis 15.

Thus, when the upstream auxiliary channels 8 are supplied with pressurized breathable gas through the elements 9 to 12, the corresponding gaseous jets strike the inclined face 13b, which deflects them in the direction of the axis 15 towards the distal end 3 ( arrow F1 in Figure 1). As shown in FIGS. 2 and 3, the upstream auxiliary channels 8 are arranged regularly around the axis of the tube 4. Their number is variable according to the uses (adult or child), but it is generally between three and nine. . The tube 4 of the system 1 can be made of any material already used in the respiratory probes, for example a polyvinyl chloride, with a possible coating of silicone or steel for high pressure injections. Of course, the dimensions of the system 1 may be very variable, essentially depending on the tube installation path and the size of the patient, which may be an adult, a child, an infant or a premature baby.

According to the invention, additional downstream auxiliary channels 17 are provided, in the thickness of the wall of the tube 4, and extend along a downstream portion of the main channel 5. These downstream auxiliary channels 17 are intended to be As a variant, they could also be connected to another source of breathable gas under pressure, distinct from that supplying the upstream auxiliary channels. As for the upstream auxiliary channels 8, the connection to the source of breathable gas S of the downstream auxiliary channels 17 can be achieved by means of a ring 18 - identical to the ring 9 and interposed between the latter and the distal end 3 - which defines a sealed annular chamber 19 around said tube 4. The downstream auxiliary channels 17 are brought into communication with the annular chamber 19, at their proximal end 17p, by means of local tear-offs 20 of the wall of the tube 4. The chamber 19 is connected to said source of breathable gas S by a supply duct 21, itself connected to the source S via a link L2.

The diameter and the number of the downstream auxiliary channels 17 are identical to those of the upstream auxiliary channels 8, although, alternatively, they could be different. The downstream auxiliary channels 17 open into a downstream recess 22 of the inner wall 14 of the tube 4. The downstream recess 22 is annular and centered on the axis 15 of said tube 4. It comprises a face 22a, substantially transverse or slightly inclined so as to constitute a downstream flare of the main channel 5, into which said downstream auxiliary channels 17 open through their orifices 23, as well as a face 22b following the face 22a and converging toward the axis 15.

Thus, when the downstream auxiliary channels 17 are supplied with pressurized gas through the elements 18 to 21, the corresponding gaseous jets strike the inclined face 22b, which deflects them towards the axis 15 towards the proximal end. 2 (arrow F2 in FIG. 1). The downstream auxiliary channels 17 are arranged regularly around the axis of the tube 4 and are, in this embodiment, aligned with the upstream auxiliai channels 8 corresponding, although they could be angularly offset from them. Furthermore, the system 1 also comprises means 24 for adjusting the flow rate of breathing gas flowing, on the one hand, in the upstream auxiliary channels 8 and, on the other hand, in the downstream auxiliary channels 17 as a function of the compressions. and decompressions on the chest of the patient in cardiac arrest. The adjustment means 24 can be moved away from the tube 4 (for example by a few meters), to make a remote adjustment of the flow of breathing gas flowing in the upstream and downstream auxiliary channels 8 and 17.

In the example of FIG. 1, the adjustment means 24 comprise a force sensor 24C intended to be applied to the thoracic cage of the patient in a cardiac arrest state. The force sensor 24C is advantageously interposed between the patient's chest and the hands of the operator performing a cardiac massage (or, alternatively, the automatic massage machine). With this sensor 24C, the adjustment means 24 instantaneously detect a compression or decompression of the patient's ribcage, which is accompanied respectively by an overpressure or a depression in the lungs thereof.

In particular: when a compression is detected by the force sensor 24C, the respiratory gas flow rate of the upstream auxiliary channels 8 is maintained, by the adjustment means 24, greater than the respiratory gas flow rate of the downstream auxiliary channels 17. A For example, the flow rate of the upstream auxiliary channels 8 is: ^ increased and that of the downstream auxiliary channels 17 conserved, reduced or even brought to zero, ^ is conserved and that of the downstream auxiliary channels 17 reduced or increased to zero; and when a decompression is detected by the force sensor 24C, the upstream auxiliary channels 8 respiratory gas flow rate is maintained, by the adjustment means 24, lower than the downstream auxiliary channels 17 respiratory gas flow rate. The flow rate of the downstream auxiliary channels 17 is, for example, increased and that of the upstream auxiliary channels 8 conserved, reduced or even brought to zero, is conserved and that of the upstream auxiliary channels reduces or reduces to zero. In this way, it is possible to control the intensity of the braking exerted on the outside air sucked up during decompressions by the downstream jets F2 and on the air fired from the patient's lungs during compression by the upstream jets F1. It will be understood that the braking intensity decreases during either decompression or compression. In a variant, the adjustment means 24 may comprise one or more pressure sensors capable of measuring the pressure inside the main channel in the vicinity of its downstream end. In addition, the adjustment of the flow rate by the adjustment means 24 is achieved by means of control valves 25 and 26 respectively mounted on the links L1 and L2 between the source S and the feed ends 12 and 18. Control valves 25 and 26, controlled for example electronically by the means 24, are able to regulate the flow of breathable gas entering the upstream auxiliary channels 8 and downstream 17. Moreover, for safety, one or more valves calibrated exhaust pipes 27 may be provided for example in the vicinity of the proximal end 2 of the tube 4, between the upstream annular recesses 13 and downstream 22, and between the distal end 3 and the ring 18. Thus, in case accidental overpressure in the main channel 5, a gas leak occurs outside the patient, through the wall of the tube 4, to instantly eliminate this overpressure. Of course, the number of exhaust valves and their arrangement may vary depending on the desired applications.

Furthermore, as shown in FIG. 1, between the upstream and downstream annular recesses 13 and 22, the wall of the tube 4 is pierced by transverse holes 28 of different diameters distributed around the axis 15. The holes 28 are covered by an outer ring 29, able to rotate smoothly around said tube 4 and itself provided with a hole 30 can be brought opposite one or other of the holes 28, by rotation of the ring external 29. The hole 30 has a diameter at least equal to that of the hole 28 of larger diameter. The outer ring 29 is trapped in the tube 4, thanks to annular lateral ribs 31. It can take at least one position for which it closes all the holes 28, or positions for which the hole 30 is aligned with each of the holes 28. , respectively. In these latter cases, each time, a passage is established between the main channel 5 and the external environment, through the corresponding hole 28. Of course, the section of such a passage is then determined by the section of the hole 28 considered. Thus, the elements 28 to 31 form means for diluting the respiratory gas originating in particular from the upstream auxiliary channels 8, which enables it to be better tolerated by patients whose body is used to a high level of carbon dioxide in the body. blood and which, in fact, can not withstand pure oxygen ventilation. Furthermore, the system 1 comprises an inner ring 32 disposed in the main channel 5 between the downstream recess 22 and the dilution means of the breathing gas 28 to 31. The inner ring 32 surrounds an oblong pressure zone by closing at least partially the peripheral space of the main channel 5 between the inner wall 14 thereof and the oblong pressure zone. The distance between the inner ring 32 and the inclined deflection face 22b is close to the diameter of the proximal portion of the main channel 5. However, it may be advantageous for this distance to be adjustable. It may also be advantageous for the diameter of the central opening of the ring to be adjustable. It will also be noted that, alternatively or in addition, a second inner ring, of the same type as the inner ring 32, can be provided between the upstream recess 13 and the dilution means of the breathing gas 28 to 31. As shown in FIG. 1, the system 1 also has obstacles, for example convergent internal fins 33, preventing the accidental introduction of an object able to seal the main channel 5. As an illustrative example, the fins 33 are arranged in the vicinity of the proximal orifices 6 and distal 7, as well as in the distal portion 3 of the tube 4. In the embodiment of Figure 1, the device is formed of a single tube 4 which comprises the upstream and downstream auxiliary channels 8 and 17. In a variant (not shown in the figures), the tube, forming the main channel, may comprise three individual sections connected together, removably, at one of their ends (for example, using fixing means). quarter turn) among which: an upstream section which carries the upstream auxiliary channels and the upstream deflection means; and an intermediate section, intended to be attached to the upstream section, which carries the downstream auxiliary channels and the downstream deflection means. Thus, thanks to the invention, when the system 1 is used to resuscitate a person in cardiac arrest subject to compression and alternating decompressions of his rib cage, the upstream and downstream auxiliary channels 17 17, are continuously fed by breathing gas from the source S. During compression, the braking carried out by the upstream jets F1 causes an increase in pressure in the lungs of the person, the air expelled from the latter escaping freely, but more difficult. Conversely, during a decompression, the outside air sucked is braked by the respiratory gas leaving the downstream auxiliary channels 17, which allows a gradual and controlled aspiration of said outside air towards the lungs of the person (the braking being decreasing intensity during decompression). This leads to the disappearance, at the beginning of the decompression, of the positive residual pressure.

Furthermore, although the artificial respiration device of the present invention has been described in the form of a probe, it may also be in the form of a rigid tubular tip formed of one or two parts nestable, intended to be mounted, removably or not, on a nasal or bucconasal artificial respiration mask or a laryngeal mask.

Claims (12)

REVENDICATIONS1. Artificial respiration device, especially for the resuscitation of a person in cardiac arrest, comprising: - a tube (4) forming a main channel (5) which is intended to be connected by its distal end (3) to a respiratory tract a patient for said main channel (5) to connect, externally, the respiratory system of said patient; at least one upstream auxiliary channel (8) capable of being connected, at its proximal end (8p), to a source of breathing gas (S) so as to be able to continuously blow an upstream jet (F1) of such respiratory gas towards said respiratory system and whose distal end (8d) opens into said main channel (5); and - upstream deflection means (13) of said upstream gas jet (F1) towards the interior of said main channel (5) arranged between the distal end (3) of the latter and the distal end (8d). ) of said upstream auxiliary channel (8), characterized in that it further comprises: - at least one downstream auxiliary channel (17) which is capable of supplying respiratory gas and whose distal end (17d) opens into said channel main (5), between the distal end (8d) of said upstream auxiliary channel (8) and the distal end (3) of said main channel (5), to be able to blow a downstream jet (F2) of such a respiratory gas in the latter towards the proximal end (2) of the main channel (5); and - downstream deflection means (22) of said downstream jet (F2) of respiratory gas towards the interior of said main channel (5), arranged between the distal end (17d) of said downstream auxiliary channel (17) and the distal end (8d) of said upstream auxiliary channel (8). 2. Artificial respiration system, especially for the resuscitation of a person in cardiac arrest, comprising an artificial respiration device as specified in claim 1, characterized in that it comprises means (24) for adjusting the flow rate. breathing gas flowing, on the one hand, in the upstream auxiliary channel (8) and, on the other hand, in the downstream auxiliary channel (17) depending on the compressions and decompressions exerted on the thoracic cage of the patient in cardiac arrest. 3. System according to claim 2, characterized in that the adjustment means (24) comprise means (24C) for detecting and decompressing the thoracic cavity of the patient, so that: - when a compression is detected by the detection means (24C), the respiratory gas flow rate of the upstream auxiliary channel (8) is maintained by the adjustment means (24) greater than the respiratory gas flow rate of the downstream auxiliary channel (17) ; and when decompression is detected by the detection means (24C), the respiratory gas flow rate of the upstream auxiliary channel (8) is maintained by the adjustment means (24) smaller than the auxiliary channel's breathing gas flow rate. downstream (17). 4. System according to claim 3, characterized in that the detection means is in the form of at least one force sensor (24C) intended to be applied to the chest of the patient in a state of cardiac arrest. 5. System according to claim 3, characterized in that the detection means is in the form of at least one pressure sensor capable of measuring the pressure inside the main channel (5) in the vicinity of its downstream end. . 6. System according to one of claims 2 to 5, characterized in that it comprises means (28, 29) for dilution of the respiratory gas from at least one of the upstream (8) and downstream ( 17). 7. System according to claim 6, characterized in that said dilution means (28, 29) are interposed between the distal ends (8d, 17d) of the upstream (8) and downstream (17) auxiliary channels. 8. System according to one of claims 2 to 7, characterized in that said tube (4) is formed of a single piece, comprising said upstream (8) and downstream (17) auxiliary channels. 9. System according to one of claims 2 to 7, characterized in that said tube (4), forming said main channel (5), comprises at least three separate sections of tube to be connected together, among which: - a upstream section which carries said upstream auxiliary channel (8) and said upstream deflection means (13); and an intermediate section, intended to be attached to the upstream section, which carries said downstream auxiliary channel (17) and said downstream deflection means (22). 10. System according to one of claims 2 to 9, characterized in that it comprises a plurality of upstream auxiliary channels (8) and a plurality of downstream auxiliary channels (17). 11. System according to one of claims 2 to 10, characterized in that it comprises at least one exhaust valve (27), preferably calibrated, capable of preventing the occurrence of overpressure in the main channel (5). . 12. System according to one of claims 2 to 11, characterized in that said adjusting means (24) are remote from said artificial respiration device, so as to be able to remotely adjust the flow of breathing gas flowing in the upstream (8) and downstream (17) auxiliary channels.