WO1994000174A1

WO1994000174A1 - Endotracheal tube with an added tip

Info

Publication number: WO1994000174A1
Application number: PCT/FR1993/000636
Authority: WO
Inventors: Thierry Brinon; Pierre Roy; Daniel Rossi
Original assignee: Vygon
Priority date: 1992-06-26
Filing date: 1993-06-24
Publication date: 1994-01-06
Also published as: JPH06509971A; FR2692789A1; CA2116697A1; EP0603357A1; FR2692789B1

Abstract

A catheter for insertion into the human body, in particular an endotracheal catheter, comprises a flexible tube (3) made of an extruded material having a suitable hardness, a flexible tubular tip (4) arranged in end-to-end abutment with the distal end edge (5) of the flexible tube (3), and made of a moulded material having a suitable hardness, and an inflatable balloon (8) consisting of a tubular sleeve positioned on the catheter near the distal end thereof and communicating with a balloon inflating/deflating system via a longitudinal channel extending through the wall of the flexible tube (3). The two axial ends (9, 10) of the balloon are attached to the flexible tubular tip (4) and the flexible tube (3) respectively.

Description

ENDOTRACHEAL PROBE WITH ADDED TIP

The present invention relates to an endotracheal tube comprising a tube to be inserted through its distal end into the trachea of a patient and provided with an inflatable balloon intended to hold the tube in place therein. The inflatable balloon is constituted by a tubular envelope threaded on the tube, located near its distal end and communicates via a longitudinal channel provided in the thickness of the wall of the tube with inflation / deflation means of the balloon.

The realization of this probe must satisfy two imperatives:

on the one hand, the distal end of the probe must be atraumatic, that is to say rounded and soft,

- on the other hand, the rest of the probe must be rigid enough to be handy and allow rapid insertion into the patient's trachea, in the event of an emergency.

Endotracheal tubes have been proposed made from a flexible tube 1, bevelled at its distal end 2, as shown in FIG. 1A. The distal end edge 2 of the tube 1 is blunt by hot deformation in a mold of suitable shape as shown schematically in FIG. 1B. Finally obtained after this heating a flexible tube whose distal end 2, visible in Figure 1C is rounded. The inflatable balloon is not shown in these figures.

The material in which the tube is made is chosen to best meet the two requirements mentioned above. However, this is only a compromise, the material being either insufficiently rigid or insufficiently flexible, and these known probes are not entirely satisfactory. We therefore sought to produce an improved endotracheal tube, which has both an atraumatic distal end, soft and rounded, and sufficient rigidity to give the tube the required maneuverability.

The present invention proposes to produce the probe by means of a flexible tube produced by extrusion in a material having a hardness chosen to give the probe sufficient rigidity and with an insert end piece edge to edge at the distal end of the tube and produced by injection molding in a material of hardness chosen to make the probe atraumatic. However, this solution poses the problem when using the probe for an accidental separation of the end piece in the event of improper attachment of the end piece and the tube, posing a fatal risk of suffocation to the patient.

This problem is solved according to the present invention by the fact that the axial ends of the balloon are fixed respectively to the end piece and to the tube. Thus, in the event of separation of the tube and the end piece, the latter remains attached to the tube thanks to the envelope of the balloon and can be quickly extracted from the patient's trachea by removing the probe.

Advantageously, the wafers in contact with the flexible tubular endpiece and the distal end of the flexible tube are bevelled in complementary ways so as to obtain a gradual variation in the mechanical properties between the flexible tube and the tubular endpiece.

In an alternative embodiment of the invention, the flexible tubular end piece is attached edge to edge at one end of an intermediate tube section, said intermediate tube section being attached at its opposite end edge against edge against edge of distal end of said flexible tube, said intermediate tube section having a hardness between that of the rest of the flexible tube and that of the flexible tubular end piece. Advantageously, said intermediate tube section consists of several segments of tubes arranged end to end and slice against slice, each of the segments being made of a material of selected hardness, so that the intermediate tube segment obtained after assembly of the different segments has a progressive variation of its hardness according to its length.

In another alternative embodiment, in which the flexible tube has at least one longitudinal channel in its thickness, the section of intermediate tube consists of several tube segments arranged end to end and edge to edge, each of the segments comprising in its thickness at least one longitudinal channel, the probe obtained having, depending on its length, a variable number of longitudinal channels. Preferably, the flexible tube and the flexible tubular end piece are made of plasticized polyvinyl chloride.

Other characteristics and advantages of the present invention will appear on reading the description which follows, of a non-limiting exemplary embodiment of the invention, and on examining the appended drawing in which:

FIGS. 1A to 1C, previously described, illustrate the state of the art on which the invention is based,

FIGS. 2A to 2C show the different stages of assembling the end piece on the flexible tube in order to form an endotracheal tube according to the invention,

- Figure 3 is a schem view ^'as an alternative embodiment in which the tube comprises an intermediate section interposed between the hub and the rest of the flexible tube,

- Figure 4 is a schematic view of an endotracheal tube according to the invention, provided at its proximal end with a connector for connection to a breathing apparatus not shown and comprising an air supply line for inflation / deflation of the balloon,

FIG. 4A is a view on an enlarged scale showing in detail the fixing of the balloon to the end piece, FIGS. 5A, 5B and 5C illustrate different configurations that the free end of the end piece can take,

FIG. 6 shows a range of endotracheal tubes of different sizes, with tips the color of which is associated with a specific size,

FIG. 7 shows the placement of the endotracheal tube in the trachea of a patient, and

- Figure 7A is a view corresponding to the circled part of Figure 7 and shows the probe seen by X-ray radiography.

We see in Figure 2 A flexible tube 3, partially shown, traversed longitudinally by a central conduit and a tubular endpiece 4 open at its two ends, intended to be attached by an end edge against the distal end edge 5 flexible tube 3. The flexible tube 3 is advantageously produced by extrusion in a material which is sufficiently rigid to give the probe good handling, preferably polyvinyl chloride having a hardness of between 75 Shore and 85 Shore (method A according to ISO 868 standard or its equivalent French NF T 51-109), and the end piece 4 is produced by injection molding in a plastic material having a hardness lower than that of the material constituting the tube 3, such as polyvinyl chloride of hardness included in the range 60- 75 Shore (method A according to the above-mentioned standard).

The end piece 4 preferably has a central duct of the same diameter as the flexible tube 3, between 1 and 10 mm and one of its axial ends, referenced 7 in FIG. 2A, is shaped during the production of the tip to facilitate the introduction of the endotra¬ cheal probe into the patient's body, and has a rounded atraumatic outline.

The opposite end edge 6 of the end piece 4 is intended to be fitted against the aforementioned distal end edge 5, and the two end edges 5 and 6 have straight sections perpendicular to the longitudinal axis of the probe. and the tip.

One could propose, as a variant, end edges 5 and 6 bevelled in complementary ways, so as to increase the contact surface between the flexible tube 3 and the end piece 4, and achieve a progressive variation in the mechanical properties between the flexible tube 3 and the nozzle 4. It is also possible, in an alternative embodiment of the invention shown in FIG. 3, to interpose between the nozzle 4 and the flexible tube 3, a section of tube intermediate 40 whose rigidity is between that of the flexible tube and that of the nozzle.

Advantageously, this intermediate section 40 consists of several tube segments 41 arranged end to end and edge to edge, each of the segments being made of a material of selected hardness, so that the tube section obtained after assembly of the different segments has a progressive variation of its hardness according to its length.

The intermediate tube section advantageously consists of several segments of tubes arranged end to end and edge to edge, each of the segments having in its thickness at least one longitudinal channel. It is thus possible to obtain a probe having a variable number of longitudinal channels according to its length, which allows for example to inject products at points spaced along the probe. The assembly of the end piece 4 on the flexible tube 3 can be carried out in many ways, for example by hot welding, by welding using a solvent or by bonding, but preferably, the assembly is produced by radio frequency welding, using radio frequency welding means 21, as illustrated diagrammatically in FIG. 2B.

Radiofrequency welding has the particular advantage of being precise and perfectly reproducible, while hot assembly causes a bead of material between the two parts welded together and the assembly using a solvent or by bonding presents risks linked to the toxicity of the solvent used.

Finally, after assembly of the endpiece 4 on the flexible tube 3, an endotracheal tube is obtained having a rounded and soft distal end 7, therefore atraumatic, and thanks to the flexible tube 3 of higher hardness, sufficient rigidity therefore good maneuverability allowing quick and safe insertion into the patient's trachea.

It will be preferred, as shown in FIG. 2C, to produce the end piece 4 with an external diameter equal to the external diameter of the flexible tube 3, so that the junction between the two parts has a smooth surface without projections. FIG. 4 shows an endotracheal tube according to the invention, that is to say comprising a flexible tube 3, a nozzle 4 attached to this flexible tube at its distal end, and an inflatable balloon 8 located at the distal end of the probe, this balloon 8 consisting of a tubular envelope, the two axial ends 9 and 10 of which apply by their internal periphery in a sealed manner to the end piece and the tube, thus delimiting an internal volume of balloon 8 ', as illustrated in FIG. 4A.

The axial ends 9 and 10 of the balloon are glued to the tube and the endpiece using a solvent-based glue, then the two projections formed on the external surface of the probe by the thickness of the free edge of each axial end is then smoothed using a brush impregnated with this glue. An external surface is then obtained without detachment capable of injuring an organ during the introduction of the probe into the patient's body. Other connection modes can of course be used such as by welding, for example. The internal volume 8 'of the balloon communicates via a longitudinal channel, not shown, provided in the thickness of the wall of the flexible tube 3, with means for inflating / deflating the balloon 8. More specifically, an air supply line 11 is provided for the balloon 8, this supply line 11 consisting of an auxiliary tube communicating at one end with the abovementioned longitudinal channel by means of a bore 12 passing through a half thickness of the wall of the flexible tube 3 and opening into this longitudinal channel. The auxiliary tube is connected at its other end, by means of a flexible pocket 13 serving as an inflation indicator, to a non-return valve or valve 14 capable of being connected, in a manner known per se, to means for inflating / deflating the balloon, not shown. The flexible tube 3 is provided at its proximal end with a connector

15, force-fitted into the central conduit of the flexible tube 3, this connector 15 serving for the connection of the endotracheal tube to a breathing aid device or other not shown.

Thanks to the fact that the axial ends 9 and 10 of the balloon 8 are fixed respectively on the one hand the end piece 4 and on the other hand on the flexible tube 3, great security is obtained in the assembly of the end piece 4 on the flexible tube 3: indeed, if the two end sections 5 and 6, for various reasons, came to detach from each other, the end piece 4 would nevertheless continue to be linked to the flexible tube 3 via the envelope of the balloon 8, and this would avoid the serious disadvantage of the loss of the tip 4 inside the trachea of the patient.

The realization of the flexible end piece 4 by injection molding makes it possible to obtain shapes for the end 7 which are impracticable in the case of traditional probes, produced by bevelling then blunting of the bevelled edge.

There is shown in Figure 5A in axial section, a flexible tip 4 which has a free end edge 7 defining an opening 20 extending in an inclined plane relative to the longitudinal axis X of the tip 4 of an angle a substantially equal to 38 °. This endpiece 4 has at its end 7 a curved portion 16 in the direction of the longitudinal axis X and the endpiece obtained is not very traumatic for the patient; this curved shape would be very difficult to obtain on the hot blunt end edges of known probes.

The shape of the nozzle presented in FIG. 5A is in no way limitative of the invention. FIG. 5B shows by way of example, a nozzle 4 'which has a free end 7' of a shape different from that of the nozzle previously described with reference to FIG. 5A.

One can also propose to laterally open the nozzle 4 to form what a person skilled in the art calls a Murphy eye, intended to increase the air flow through the nozzle 4, and to make ventilation more symmetrical lungs. The production of the endpiece by injection molding makes it possible to produce Murphy's eye referenced 30 in FIG. 5C during the molding step and with atraumatic rounded edges. Advantageously, the flexible tip 4 is produced in a color chosen as a function of the size of the tip in a set of different colors, each associated with a specific size of tip.

A range of endotracheal tubes is shown for information only in Figure 6. The inflatable balloon is not shown in these figures for the sake of clarity of the drawings. Such endotracheal tubes are then easily distinguishable by the user, and in an emergency, this characteristic makes it possible to obtain an appreciable gain in speed. One could also propose, as a variant, different colors associated with particular geometries of the end piece, as described with reference to FIGS. 5A to 5C.

It is also possible, advantageously, to produce the end piece 4 in a plastic material opaque to X-rays, so as to visualize, possibly in real time, the placement of the endotracheal tube in the patient's trachea, like this is illustrated schematically in Figures 7 and 7A.

The invention advantageously makes it possible to concentrate the opacifier on X-rays only at the distal end of the probe and on its entire periphery therefore to obtain a better visibility of the latter, and not along a continuous line of the probe as is the case for known probes.

Finally, an endotracheal tube according to the invention makes it possible to benefit from the advantages linked to the use of an end-piece 4 produced by molding and attached against the distal end edge of the flexible tube 3 without causing the patient the risk of suffocation in the event of accidental separation of the nozzle and the tube.

Claims

R E V E N D I C A T I O N S

1 / Probe to be introduced into the human body, in particular an endotracheal probe, comprising a flexible tube (3) produced by extrusion and an inflatable balloon (8) constituted by a tubular envelope threaded on the probe, located near its distal end, and communicating via a longitudinal channel provided in the thickness of the wall of the flexible tube (3) with means for inflating / deflating the balloon, characterized in that the probe comprises a flexible tubular endpiece (4) attached to the edge against edge against edge of distal end (5) of the flexible tube (3), produced by injection molding and in that the two axial ends (9, 10) of the balloon are fixed respectively to the flexible tubular endpiece (4 ) and on the flexible tube (3).

2 / probe according to claim 1, characterized in that the sections (5, 6) in contact with the flexible tubular endpiece (4) and the distal end of the flexible tube (3) are bevelled in complementary ways so as to obtain a gradual variation in the mechanical properties between the flexible tube (3) and the flexible tubular endpiece (4).

3 / Probe according to one of claims 1 and 2, characterized in that the flexible tubular endpiece (4) is added edge to edge at one end of an intermediate tube section (40), said intermediate tube section being attached at its opposite end edge to edge against the distal end edge (5) of the rest of the flexible tube (3), said intermediate tube section having a hardness between that of the rest of the flexible tube and that of the flexible end piece tubular (4).

4 / A probe according to claim 3, characterized in that said intermediate tube section consists of several tube segments (4) arranged end to end and edge against edge, each of the segments (4) being made of a material of selected hardness , so that the intermediate tube section obtained after assembly of the different segments has a progressive variation in its hardness according to its length.

5 / probe according to one of claims 3 and 4, characterized in that the intermediate tube section consists of several segments of tubes arranged end to end and edge against edge, each of the segments having in its thickness at least one longitudinal channel , the probe obtained having, depending on its length, a variable number of longitudinal channels. 6 / Probe according to one of claims 1 to 5, characterized in that the flexible tube (3) and the flexible tubular end piece (4) are made of plasticized polyvinyl chloride.

7 / Probe according to one of claims 1 to 6, characterized in that the flexible tubular end piece is made in a color chosen according to its size in a set of different colors each associated with a specific size.

8 / Probe according to one of claims 1 to 7, characterized in that the flexible tubular endpiece (4) is assembled on the flexible tube (3) or the section of intermediate tube section wafer against wafer by radio frequency welding.

9 / Probe according to one of claims 1 to 8, characterized in that the flexible tubular end piece (4) is made of a plastic material opaque to X-rays. 10 / Probe according to one of claims 1 to 9, characterized in that the flexible tube is made of a material having a hardness of between 75 and 85 Shore (method A according to ISO standard 868) and the end piece in a material having a hardness of between 60 and 75 Shore (method A according to the ISO 868).