WO1980000307A1

WO1980000307A1 - Tracheal tubes

Info

Publication number: WO1980000307A1
Application number: PCT/GB1979/000125
Authority: WO
Inventors: D Cross; H Martin; G Lester
Original assignee: Smiths Industries Ltd
Priority date: 1978-08-10
Filing date: 1979-07-25
Publication date: 1980-03-06
Also published as: FI792308A; DK116580A; JPS55500571A; IT1120502B; ES483156A1; IT7950015A0; AU4928179A; EP0016120A1; GB2028139A; YU191879A; NZ191173A

Abstract

A tracheostomy tube has a tubular section (1), one end of which is located in the trachea of a patient. The other end (5) has a screw thread (13) on its outer surface that engages with a co-operating screw thread (21) on the inner surface of a connector portion (2) of the tube. The connector portion (2) is located outside the patient's trachea and carries a mounting flange (40) by means of which the tube is secured to the patient's neck. The flange (40) is rotatable relative to the body (20) of the connector portion (2) and carries an elongate key (47) which extends parallel to the axis of the tubular section (1). The key (47) projects through a keyway (48) formed at the end of the tubular section (1) so as thereby to prevent relative rotation between the flange (40) and the tubular section.

Description

Tracheal Tubes

This invention relates to trachea! tubes of the kind for making fluid connection with a patient's trachea, the tube having a first portion for insertion within the trachea, and a second portion for location externally of the trachea and adapted for enabling external fluid connection to be mads to the tube.

The invention is especially concerned with tracheostomy tubes, that is, tubes which are used to provide an airway through an opening in a patient' s neck directly into the trachea. Such tubes are well known and are commonly used during and following surgery to enable ventilation of the patient' s lungs. Tracheostomy tubes are usually secured to the patient by means of a flange mounted on the tube which is arranged to be located close to the surface of the patient's neck, the flange being provided with slots through which a strap may be passed. Connection to tracheostomy tubes is made by means of a connector mounted at one end of the tube to which an airline from a ventilator machine may be secured. The distance by which the trachae is spaced from the surface of the neck varies according to the build of the patient. Because of this, difficulties have been experienced in securing tracheostomy tubes in position without putting undue pressure on the wall of the trachea. If a tracheostomy tube having a flange mounted at a fixed position along its length is used, for example, on a patient whose trachea is close to the surface of his neck then the flange will generally be spaced from this surface and any attempt therefore to strap the flange to his neck will put pressure on the far surface of the trachea. Similarly, with a patient whose trachea is spaced by a greater distance from the surface of his neck, the tube may compress the tissue between the trachea and the surface of the neck.

One way of overcoming this difficulty has been to locate the flange on such tracheostomy tubes at a distance sufficient to accommodate the greatest separation likely to be experienced between the trachea and the neck surface, and then to place gauze padding between the flange and neck when the tube is used on patients where this separation is less. This arrangement suffers from the dis advantage that the gauze padding, being porous, will absorb fluid exuded from the opening in the neck and will provide a site for bacterial infection of the wound.

An alternative way of overcoming the difficulty of fitting a tube of one size to different patients is to arrange for the position of the flange to be adjustable along the length of the tube. The flange of such tubes must, however, be firmly secured with the tube when in its correct position so as to avoid displacement in use. One problem with such arrangements has been that it has been difficult to secure the flange firmly to the smooth outer surface of the tube especially where the tube becomes damp after use. Another disadvantage of both the above previous arrangements has been that they require a relatively long length of tube to project from the patient's neck. Because of the additional leverage this causes, the weight of external fluid lines connected to the tube can result in an increase in pressure at the neck opening with consequent discomfort and possible injury. The additional weight of that portion of the tube projecting from the neck also contributes to an increase in pressure. The increased length of the projecting portion, moreover, makes it more likely to be inadvertently jolted or to be caught on clothing and bedding.

It is an object of the present invention to provide a tracheal tube that can be used to alleviate the above mentioned difficulties and disadvantages.

According to one aspect of the present invention there is provided a tracheal tube of the specified kind, characterised in that the first portion is provided by one end of a tubular section that is arranged for axial displacement relative to the second portion such that the overall length of the tube can thereby be altered.

The position of the tubular section can in this way be adjusted to prevent undue pressure being applied to the trachea and, since the overall length of the tube can be adjusted, the length projecting from the trachea can be reduced to a minimum. The other end of the tubular section may be formed with a screw-threaded portion that engages with a co-operating screw-threaded portion on the second portion. The second portion may include a cylindrical body portion and a mounting member for securing with the patient's body, the screw- threaded portion may be formed on the interior of the body portion and the body portion may be free for rotation about its axis relative to the mounting member. The mounting member and the other end of the tubular section may be provided with a co-operating key and keyway that are arranged to prevent rotation of the mounting member relative to the tubular section. The tubular section may have an inflatable cuff extending around it close to the one end. The tubular section may, in this case, have a lumen extending through its wall along a part at least of its length, the lumen opening into the cuff so as thereby to enable inflation of the cuff by passage of fluid through the lumen. A tracheostomy tube in accordance with the present invention, will now be described, by way of example, with reference to the accompanying drawings, in which :

Figure 1 is a partly cross section elevation showing the tube in position in a patient's trachea;

Figure 2 is a cross-section, to an enlarged scale, of a part of the tube of Figure 1;

Figure 3 is a cross-section through the tube along the line

III - III of Figure 2;

Figure 4 is a cross-section through the tube along the line

IV - IV of Figure 3; and

Figure 5 is a perspective view of the tube showing an alternative arrangement for making connection to the tube. With reference to Figures 1 to 4; the tracheostomy tube consists of a tubular section 1 and a connector 2.

The tubular section 1 has a patient end 3 for location within the trachea 4 of a patient, and a machine end 5 which can be screwed into or out of the connector 2 so as to adjust the overall length of the tube. The term 'patient end' is used to denote those parts closest the patient whilst the term 'machine end' is used to denote those parts furthest away from the patient, or closest the ventilator machine used with the tube.

The tubular section 1 is of extruded PVC, being bent at about 110 degrees along its length, and has a rounded tip 6 at its patient end 3 to prevent injury owing to rubbing or abrasion when in position. An inflatable cuff 7 extends about the tubular section 1 close to the patient end 3 and when inflated provides a seal with the trachea wall reducing fluid leakage past the tube. Fluid can be supplied to the interior of the cuff 7 via a secondary lumen 8 (Figures 3 and 4) which extends through the wall of the tubular section 1 along its length. One end of an inflation line 9 is connected to the secondary lumen 8 at the machine end 5 of the tubular section 1 and extends out through the connector 2. The other end of the inflation line 9 has a pilot balloon 10, the interior of which communicates with the inflation line so that when the cuff 7 is inflated the pilot balloon will also be inflated and will thereby give an indication of the state of the cuff. The inflation line 9 is terminated by a Luer connector 11 which serves to make connection with, for example, a syringe that can be used to supply a measured amount of fluid to inflate the cuff 7.

At the machine end 5 of the tubular section 1 there is mounted a moulded polycarbonate or acetal boss 12. The boss 12 is about 10 mm long and extends around the machine end 5 within the connector 2, being formed with three or four turns of a screw-thread

13 in its outer surface. At the machine end of the boss 12 there is a smooth, unthreaded portion 14 of reduced diameter. The connector 2, which is also of moulded polycarbonate or acetal, includes a cylindrical body portion 20 within which projects the machine end 5 of the tubular section 1. The body portion 20 is formed on its inner surface with a screw-thread 21 which extends about 21 mm along its length and which engages with the screw-thread 13 on the boss 12. The machine end of the body portion 20 is formed with a portion 22 of reduced diameter having an open end 23 which is normally closed by a cap 24 of resilient material. The cap 24 has a cylindrical portion 25 which fits over the end of the reduced diameter portion 22 of the connector body 20 and which has a central aperture 26. The aperture 26 can be closed by means of a plug 27 formed at one end of a strap 28; the cylindrical portion 25, the plug and the strap being an integral, moulding. A cylindrical port 29 extends approximately at right angles radially of the reduced diameter portion 22 and it is via this port that connection is made to the tube by an airline 30 from a ventilator machine (not shown). A mounting flange 40 is fastened to the patient end of the connector 2. The flange 40 is moulded of PVC having a tubular sleeve portion 41 formed with an inturned lip 42 and two tongues 43 (Figures 3 and 4 ) which extend radially at its patient end. Both tongues 43 have a slot 44 that is used to receive a strap that can be tied around the patient's neck, or a strip of adhesive tape that can be stuck to the neck so as to secure the tube in position. The inner surface of the sleeve portion 41 has a groove 45 which mates with a co-operating raised ring 46 formed around the outer surface of the connector 2 close to its patient end. The flange 40 is also provided with an elongate key portion 47 about 19 mm in length and of rectangular cross section. The key portion 47 extends within the body portion 20 of the connector 2 parallel to its axis and projects through a rectangular keyway 48 in the boss 12. The key portion 47 and the keyway 48 prevent rotation of the flange 40 relative to the tubular section 1 and therefore ensure correct alignment of the two parts, that is, with the tongues 43 of the flange horizontal when the tube is in position.

With the flange 40 in position on the connector 2, the lip 42 forms an interference fit with the outer surface of the tubular section 1, which restricts fluid leakage between the connector 2 and the tubular section but which does not prevent axial displacement of the connector relative to the tubular section.

Rotation of the connector 2 relative to the tubular section 1 causes the boss 12, and hence the machine end 5 of the tubular section to be screwed into or out of the connector by engagement of the two screw threads 13 and 21. Since the flange 40 is mounted on the connector 2 it will also be moved along the length of the tubular portion 1 when the connector is rotated,so as thereby to accommodate for the different distance between the trachea and the surface of the neck in different patients. Screwing the connector 2 onto the tubular section 1 in this manner also reduces the length of tube projecting from the neck. The leverage exerted on the tube owing to the weight of the airline 30 connected to the connector wili thereby be reduced.

The manner in which the inflation line 9 communicates with the secondary lumen 8 will now be described with reference to Figures 3 and 4.

The inflation line 9 extends, as a sliding fit, through a hole 50 inthe cylindrical wall of the flange 40. The open patient end 51 of the inflation line 9 projects into, and is sealed within, a small-diameter bore 52 that extends through the boss 12. The bore 52 communicates with the secondary lumen 8 at the machine end 5 of the tubular portion 1 via a notch or groove in the wall of the tubular portion above the lumen. The machine end of the bore 52 is sealed by a plug 53 of plastics material so that air or other fluid can thereby be supplied to the lumen 8 via the inflation line 9. Displacement of the machine end 5 of the tubular portion 1 within the connector 2 causes the inflation line 9 to be drawn through the hole 50 in the flange 40, there being adequate space between the outer surface of the tubular portion and the inner surface of the connector to prevent the inflation line being pinched when the tubular portion is in its fully extended position.

Connection may be made to the port 29 directly by an airline 30 from a ventilator machine, as shown in Figure 1, or via an additional swivel connector 60 of the form shown in Figure 5. The swivel connector 60 is of a rigid plastics material having a tubular body portion 61 with .an open end which is of a suitable shape and size to receive the port 29 within it in a fluid-tight slip-fit. The other end of the swivel connector 60 is provided with a sleeve 63 which is closed at one end and which has a port 64 extending from it at approximately right-angles to its axis. The sleeve 63, and hence the port 64 are rotatable about the axis of the swivel connector 60 so as to enable the port to be positioned at a convenient location for receiving an airline 65 from a ventilator machine. In this way, the connector 2 and the swivel connector 60 can be arranged such that pressure at the opening in the patient's neck caused by weight of the airline 65 is reduced.

It is necessary, during use of tracheostomy tubes, periodically to remove deposits of mucus or other bodily products that may build up on the inside of the tube. This is generally performed, without removing the tube from the neck, by passing a flexible tube through the bore of the tracheostomy tube and applying suction to the flexible tube to suck out any accumulated deposits. In the tracheostomy tube described above, a flexible suction-tube may be readily introduced to the tracheostomy tube by removing the plug 27 from the aperture 26 of the cap 24 (or by removing the cap 24 entirely) and inserting the suction-tube through the open end 23 of the connector 2; it is not necessary to disconnect the airline 30 or 65 from the connector in order to carry out this cleaning. Cleaning of the tube is facilitated in this arrangement by the positioning of the inflation line 9. Since the inflation line 9 extends from the connector 2 through the flange 40 and extends only in that part of the connector between the boss 12 and the flange, the inflation line is not exposed to bodily products and does not provide a surface on which these products can accumulate. Access to the connector 2 and tubular portion 1 through the open end 23 is also made more easy than would be the case if the line 9 emerged from the connector through the open end.

The machine end 5 of the tubular section 1 need not be screw-threaded, it would be possible, for example, to arrange for the machine end to be a sliding fit within the connector 2 and for the connector to be provided with means for clamping it firmly to the tubular section. The connector 2 could, for example, be formed with a screw-thread on its outer surface and have a nut engaging this screw-thread that is tightened to compress the connector about the tubular section 1. Alternatively, the inner surface of the connector 2 and the outer surface of the tubular section 1 could be eccentrically shaped such that the tubular section is normally free to slide within the connector but, upon twisting one part relative to another, the two parts become locked together. Whilst these alternative arrangements have the advantage of providing a tracheostomy tube of compact form, in which the length of tube projecting from a patient's neck can be reduced, the tubular section may be more prone to slip within the connector when the tube becomes damp than would be the case with the screw-threaded arrangement described above.

The tubular section need not necessarily extend within the connector,. it could alternatively be arranged that the connector extends within the tubular section.

The invention has application to medico-surgical tubes other than tracheostomy tubes and, in general, may be used on tubes which extend through an opening in the body of the patient and which are required to be positioned accurately relative to the body surface.

Claims

1. A tracheal tube for making fluid connection with a patient's trachea, the tube having a first portion for insertion within the trachea, and a second portion for location externally of the trachea and adapted for enabling external fluid connection to be made to the tube, characterised in that the first portion is provided by one end (3) of a tubular section (1) that is arranged for axial displacement relative to the second portion (2) such that the overall length of the tube can thereby be altered.

2. A tube according to Claim 1, characterised in that the tubular section (1) is arranged for axial displacement within the second portion (2).

3. A tube according to Claim 1, characterised in that the other end (5) of the tubular section (1) is formed with a screw-threaded portion (13) that engages with a co-operating screw-threaded portion (21) on the second portion (2).

4. A tube according to Claim 3, characterised in that the second portion (2) includes a cylindrical body portion (20) and a mounting member (40) for securing with the patient's body, that the screw-threaded portion (21) on the second portion (2) is formed on the interior of the body portion (20), and that the body portion (20) is free for rotation about its axis relative to the mounting member (40).

5. A tube according to Claim 4, characterised in that the mounting member (40) and the other end (5) of the tubular section (1) are provided with a co-operating key (47) and a keyway (48) that are arranged to prevent rotation of the mounting member (40) relative to the tubular section (1).

6. A tube according to Claim 5, characterised in that the key is provided by an elongate portion (47) extending from the mounting member (40) parallel to the axis of the tubular section (1), and that the keyway (48) is formed in the other end (5) of the tubular section (1).

7. A tube according to any one of the preceding claims, characterised in that the tubular section (1) has an inflatable cuff (7) extending around it close to the one end (3).

8. A tube according to Claim 7, characterised in that the tubular section (1) has a lumen (8) extending through its wall along a part at least of its length, and that the lumen (8) opens into the cuff (7) so as thereby to enable inflation of the cuff (7) by passage of fluid through the lumen (8).