GB2428200A

GB2428200A - Finger mounted tracheotome

Info

Publication number: GB2428200A
Application number: GB0612797A
Authority: GB
Inventors: Joanna Byatt
Original assignee: Smiths Group PLC
Current assignee: Smiths Group PLC
Priority date: 2005-07-09
Filing date: 2006-06-28
Publication date: 2007-01-24
Anticipated expiration: 2026-06-28
Also published as: GB0514130D0; GB0612797D0; GB2428200B

Abstract

A tracheostomy instrument for use in blunt disection has a spring-loaded needle 30 and cannula 40 in a sleeve 1. The sleeve has a clip 14 by which it can be secured to the finger of the surgeon. When the surgeon's finger is adjacent the trachea he pushes the needle and cannula assembly 3 against the action of the spring 36 to extend it beyond the sleeve 1 and penetrate the trachea. A latch 18 in the sleeve 1 holds the cannula 40 in the extended position when the needle 30 is released and retracted into the sleeve. This allows a guidewire 54 to be inserted so that the instrument can be removed and leave the guidewire in position.

Description

* 2428200 TRACHEOSTOMy INSTRUMENTS This invention relates to tracheostomy

instruments.

In blunt dissection techniques for forming a tracheostomy, the surgeon cuts through the outer tissue of the neck overlying the trachea and uses his finger to separate underlying tissue and locate the external wall of the trachea. He then makes an incision using a needle through the wall of the trachea so that a guidewire can be introduced, followed by a dilator and the tracheostomy tube, in the usual way. During the insertion of the needle through the tracheal wall there is a relatively high risk of needle-stick injury to the surgeon because his finger has to be kept in close proximity to the site of entry of the needle.

It is an object of the present invention to provide an alternative tracheostomy instrument.

According to the present invention there is provided a tracheostomy instrument including a sleeve member, a needle assembly with a cutting tip slidably mounted in the sleeve member and movable from a first position in which the cutting tip is protected within the sleeve member to a second position in which the cutting tip is exposed at the forward end of the sleeve member, and means for mounting the instrument on a finger of the user such that the sleeve member can be pushed with the finger through tissue overlying the trachea while the cutting tip is protected and such that the cutting tip can then be exposed to penetrate the trachea.

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The forward end of the sleeve member preferably extends substantially level with or just forwardly of the end of the finger on which the instrument is mounted. The mounting means is preferably a clip arranged to embrace the finger. The clip may be C shape in section. The needle assembly is preferably spring mounted within the sleeve member and is urged by the spring to the first position. The needle assembly preferably includes a flexible cannula slidably mounted on the outside of a rigid needle. The instrument is preferably arranged such that the cannula is retained in an extended position when the needle is retracted. The cannula may have a flange towards its rear end arranged to move past a latching member on the sleeve member when the needle assembly is moved to the second position and to be retained by the latching member when the needle assembly moves back to the first position. The instrUment preferably also includes a guidewire arranged to be advanced into the trachea through the instrument so that the instrument can subsequently be withdrawn to leave the guidewire in place.

A tracheostomy instrument according to the present invention will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a perspective view of the instrument with the needle retracted; Figure 2 is a perspective view of the instrument with the needle extended;

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Figure 3 is a perspective view of the instrument in ghost outline showing the needle retracted; Figure 4 is a cross-sectional side elevation view of the instrument with the needle retracted; and Figures 5A to SD show different steps in use of the instrument.

With reference first to Figures 1 to 4, the instrument includes an outer sleeve member I containing a hollow needle assembly 3, which is movable from a first, retracted position shown in Figures 1,3 and 4 to a second, extended position shown in Figure 2.

The sleeve member I is of a plastics material and has a circular section with a forward portion 10 having a smoothly rounded and bevelled end 11 and which tapers rearwardly to an increased diameter. The forward portion 10 is fixedly attached with an intermediate portion 12 of constant external diameter and this, in turn, is fixedly attached to a rear portion 13, which forms a smooth continuation of the external surface of the intermediate portion. Externally, the sleeve member I also includes a finger clip 14 in the form of a part-cylindrical collar of C shape in section attached midway along the forward portion 10 and aligned parallel with the axis of the forward portion. The fmger clip 14 is preferably moulded integrally with the forward portion 10 as a single piece. The dimensions and location of the finger clip 14 along the forward portion are such that it securely embraces and grips the finger of the user with the tip of the finger substantially level with the end 11 of the

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sleeve 1, or with the tip of the finger displaced slightly rearwardly relative to the end of the sleeve. Instead of having the finger clip in a fixed position relative to the sleeve member it could be displaceable relative to it. For example, the finger clip could be pivoted so that the sleeve member can be angled relative to it by up to 900.

Internally, the forward portion 10 has an axial bore 16 opening into a radially enlarged bore 17, which extends along the intermediate portion 12. The intermediate portion 12 has two resilient, inclined latching teeth 18 projecting inwardly into the bore 17 for a purpose that will become apparent later. The rear portion 13 has an axial bore 19 aligned with the bores 16 and 17 through the forward and intermediate portions 10 and 12. The diameter of the bore 19 through the rear portion 13 is slightly less than that of the bore 17 through the intermediate portion 12. At the forward and rear ends of the bore 19 there are inwardly-projecting annular lips 20 and 21.

The needle assembly 3 comprises a hollow, rigid, metal needle 30 with a bevelled, cutting tip 31 at its forward end. At its rear end 32, the needle 30 is bonded into a bore 33 through a push button 34. The push button 34 has an outwardly-projecting lip 35 around its forward end, which is a sliding fit along the bore 19 through the rear portion 13. The annular lip 21 at the rear end of the bore 19 engages the lip 35 on the push button 34 and prevents it coming out of the rear end of the rear portion 13. A helical spring 36 extends along and around the needle 30 within the bore 19. The forward end of the spring 36 bears on the forward lip 20 of the rear portion 13; the rear end of the spring bears on the forward end of the push button 34. The natural length of the spring 36 is greater than that of the bore 19 so that it is held in compression and applies a force to the push button 34, and hence to the needle 30, urging it rearwardly.

The needle assembly 3 is completed by a flexible, plastics cannula 40, which is a close siiding fit along the outside of the needle 30. As shown in Figure 4, the cannula 40 extends from just rearwardly of the forward end 31 of the needle 30 to a location adjacent the forward end of the rear portion 13. At its rear end, the cannula 40 has a rigid plastics hub 41 bonded to its outside. The hub 41 has a tapered annular flange 42 at its forward end the dimensions of which are such that it cooperates with the latching teeth 18 on the intermediate portion 12. More particularly, when the user pushes in the push button 34 to its full extent, the needle 30 moves forwardly and carries the cannula 40 with it. As the hub 41 of the cannula 40 moves between the teeth 18, the tapered forward edge of the flange 42 moves the teeth slightly apart against their resilience. They then snap back inwardly onto the hub 41 to the rear of the flange 42. In this position, both the needle 30 and cannula 40 are extended beyond the forward end of the sleeve member 1. When the push button 34 is released, the spring 36 pushes it and the needle 30 rearwardly relative to the sleeve member 1 so that the cutting tip 31 is safely retracted within the sleeve member. The cannula 40, however, remains in the extended position because the teeth 18 prevent the hub 41 retracting rearwardly.

The method in which the instrument is used will now be described, with reference to Figures 5A to SD. First, as shown in Figure 5A, a scalpel 50 is used to cut through the skin and top layer of tissue 5! overlying the trachea 52. Next, as shown in Figure 5B, the instrument is clipped onto the user's fmger (most usually the little finger) and the finger and

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instrument are pushed through the incision to separate the pretracheal tissue and locate the anterior wall 53 of the trachea 52 by blunt dissection. Once the trachea 52 has been located, the push button 34 on the instrument is pushed in, with the end 11 of the sleeve 1 in contact with or closely adjacent the outside of the tracheal wall 53, so that the needle 30 and cannula are extended and pushed through the waIl 53 into the trachea 52, as shown in Figure 5C.

The button 34 is then released so that the needle 30 retracts into the instrument but leaves the cannula 40 extending into the trachea 52. A guidewire 54 is then pushed through the bore 33 of the button 34, along the bore of the needle 30 and canaula 40 until its forward end locates in the trachea 52, as shown in Figure SD. The instrument is.then removed leaving the guidewire 54 in the trachea 52. One or more dilators (not shown) are then slid along the guidewire 54 in the usual way to enlarge the opening into the trachea 52 sufficiently for a tracheostomy tube (not shown) to be inserted.

The instrument could include some means for detecting penetration of the trachea.

This could be some form of carbon dioxide detector, such as a colourchange chemical or a capnograph. Alternatively, the needle could include a rod extending within it along its length with its forward end projecting from the tip of the needle and the rear end coupled to a flag or some other indicator. A spring would urge the rod forwardly so that the rod and indicator move forwardly as soon as the trachea is penetrated. By observing the indicator it can be determined whether or not the trachea has been penetrated. This is similar to the arrangement described in GB2393398.

Claims

I. A tracheostomy instrument including a sleeve member, a needle assembly with a cutting tip slidably mounted in the sleeve member and movable from a first position in which the cutting tip is protected within the sleeve member to a second position in which the cutting tip is exposed at the forward end of the sleeve member, and means for mounting the instrument on a finger of the user such that the sleeve member can be pushed with the finger through tissue overlying the trachea while the cutting tip is protected and such that the cutting tip can then be exposed to penetrate the trachea.
2. An instrwnent according to Claim 1, wherein the forward end of the sleeve member extends substantially level with or just forwardly of the end of the fmger on which the instrument is mounted.
3. An instrument according to Claim I or 2, wherein the mounting means is a clip arranged to embrace the finger.
4. An instrument according to Claim 3, wherein the clip is C shape in section.
5. An instrument according to any one of the preceding claims, wherein the needle assembly is spring mounted within the sleeve member and is urged by the spring to the first position.
6. An instrument according to any one of the preceding claims, wherein the needle assembly includes a flexible cannula slidably mounted on the outside of a rigid needle.
7. An instrument according to Claim 6, wherein the instrument is arranged such that the cannula is retained in an extended position when the needle is retracted.
8. An instrument according to Claim 7, wherein the cannula has a flange towards its rear end arranged to move past a latching member when the needle assembly is moved to the second position and to be retained by the latching member when the needle assembly moves back to the first position.
9. An instrument according to any one of the preceding claims including a guidewire arranged to be advanced into the trachea through the instrument so that the instrument can subsequently be withdrawn to leave the guidewire in place.
10. A tracheostomy instrument substantially as hereinbefore described with reference to the accompanying drawings.
11. Any novel and inventive feature or combination of features as hereinbefore described.