Patent Publication Number: US-2022211961-A1

Title: Tracheostomy tube assemblies and protectors

Description:
TRACHEOSTOMY TUBE ASSEMBLIES AND PROTECTORS 
     This invention relates to tracheostomy tube assemblies of the kind including a tracheostomy tube having a shaft with an inflatable sealing cuff towards its patient end and an inflation line communicating with the sealing cuff and having an inflation indicator towards its machine end. 
     Tracheal tubes are used to enable ventilation, respiration or spontaneous breathing of a patient. Endotracheal tubes are inserted via the mouth or nose so that one end locates in the trachea and the other end locates outside the patient. Tracheostomy tubes are inserted into the trachea via a surgically-formed opening in the neck. Tracheostomy tubes can be inserted by different techniques, such as the surgical cut-down procedure carried out in an operating theatre or a cricothyroidotomy procedure, which may be carried out in emergency situations. 
     Tracheostomy tubes are generally used for more long-term ventilation or where it is not possible to insert an airway through the mouth or nose. The patient is often conscious while breathing through a tracheostomy tube, which may be open to atmosphere or connected by tubing to some form of ventilator. The tube is secured in position by means of a flange fixed with the machine end of the tube and positioned to extend outwardly on opposite sides of the tube. 
     Tracheal tubes often have a sealing cuff on their outside close to the patient end. This usually takes the form of a cuff that is inflated by a gas or liquid so that, when inflated, it forms a seal with the tracheal wall, confining gas flow along the bore of the tube and preventing flow around its outside. The cuff is usually inflated and deflated by means of an inflation line in the form of a small-bore tube opening into the cuff at its patient end and extending along a channel along the outside of the shaft of the tube. The machine end of the inflation line extends freely beyond the channel and is terminated by a combined inflation indicator, connector and valve. Alternatively, the tracheal tube may have an inflation lumen extending within the wall of the shaft of the tube and joined towards the machine end of the shaft with a separate small-bore inflation tube. The nose of a syringe or the like is inserted in the connector, opening the valve so that inflation gas or liquid can be supplied to or from the sealing cuff via the inflation line. The inflation indicator usually takes the form of a small flexible envelope or balloon connected at one end with the connector. The inflation line extends and opens into the interior of the inflation indicator so that the indicator is inflated by pressure in the sealing cuff and inflation line. If the pressure in the sealing cuff should fall this would be indicated by a corresponding deflation of the inflation indicator. 
     A problem occurs when tracheostomy tubes with such indicators are used with children. The soft nature of the inflation indicator and the proximity of the inflation indicator to the child&#39;s mouth means that the indicator can be easily chewed or bitten. This is a problem because, if the indicator or inflation line should be damaged, it may permit the inflation gas or liquid to escape thereby allowing the sealing cuff to deflate. This could allow ventilation gas to pass around the outside of the tracheostomy tube and prevent correct ventilation of the patient. The child chewing the inflation line and indicator may also ingest a part of the indicator. 
     It is an object of the present invention to provide an alternative tracheostomy tube assembly. 
     According to one aspect of the present invention there is provided a tracheostomy tube assembly of the above-specified kind, characterised in that the assembly also includes a protective enclosure extending around and enclosing the inflation indicator to protect it from damage by chewing, and that the protective enclosure is transparent, at least in part, to enable the inflation indicator to be viewed through the enclosure. 
     The protective enclosure preferably has a first part arranged to receive a machine end of the inflation indicator and a second part having a transparent sleeve adapted to extend around the inflation indicator and fit with the first part. The second part is preferably open at its machine end that fits with the first part, and the second part preferably has an opening at its patient end through which the inflation line extends and has a slot extending along its length between the open machine end and the opening at the patient end so that the inflation line can be threaded through the slot. The second part may have a projecting rim at one end adapted to engage a groove around the first part. The inflation indicator preferably has a substantially flat inflatable balloon, the protective enclosure including two opposite slots aligned with opposite edges of the balloon. The protective enclosure may include at least one projecting feature adapted to be chewed by the patient. The at least one projecting feature may be provided by two flanges oriented with the planes of the flanges substantially orthogonal to one another. 
     According to another aspect of the present invention there is provided a protector for an inflation indicator of a tracheostomy tube, characterised in that the protector is adapted to extend around and enclose the inflation indicator to protect it from damage by chewing, and that the protector is transparent, at least in part, to enable the inflation indicator to be viewed through it. 
     The protector may have a first part arranged to receive the machine end of the inflation indicator and a second part having a transparent sleeve adapted to extend around the inflation indicator and fit with the first part. The sleeve may be open at its machine end that fits with the first part, and the sleeve may have an opening at its patient end through which the inflation line extends and have a slot extending along its length between the open machine end and the opening at the patient end so that the inflation line can be threaded through the slot. 
     According to a further aspect of the present invention there is provided a tracheostomy tube assembly including a tracheostomy tube having an inflatable sealing cuff towards its patient end and an inflation line terminated by an inflation indicator at its machine end, characterised in that the assembly includes a protector for the inflation indicator according to the above other aspect of the present invention. 
     According to a fourth aspect of the present invention there is provided a method of forming a paediatric tracheostomy tube assembly including the steps of providing a paediatric tracheostomy tube with a sealing cuff and an inflation indicator, providing a protective enclosure in two parts comprising a base part and a transparent sleeve, fitting the sleeve over an inflatable part of the inflation indicator, and joining one end of the sleeve to the base part such that the machine end of the inflation indicator is received in the base part. 
     The transparent sleeve preferably has a slot extending longitudinally of the sleeve between openings at opposite ends of the sleeve such that the inflation line can be threaded sideways through the slot and then the sleeve can be slid along the inflation line to enclose the inflation indicator. 
     According to a fifth aspect of the present invention there is provided a paediatric tracheostomy tube assembly of a tracheostomy tube and a protector formed by a method according to the above fourth aspect of the present invention. 
     A paediatric tracheostomy tube assembly with an inflation indicator and protector, both according to the present invention will now be described, by way of example, with reference to the accompanying drawings in which: 
    
    
     
         FIG. 1  is a perspective view of the tracheostomy tube assembly; 
         FIG. 2  is an enlarged perspective view of the inflation indicator from one end; 
         FIG. 3  is an enlarged perspective view of the inflation indicator from the opposite end; 
         FIG. 4  shows the parts of the inflation indicator before assembly; 
         FIG. 5  is a perspective view of a modified embodiment of the protector from its patient end; and 
         FIG. 6  is a perspective view of the modified embodiment of the protector from its machine end. 
     
    
    
     With reference first to  FIGS. 1 to 4 , the assembly includes a tracheostomy tube  1  of a paediatric size having a curved shaft  10  of circular section and with an inner diameter of around 6mm. The shaft  10  has a patient end  12  adapted to be located within the trachea of the patient and has a conventional sealing cuff  13  towards its patient end. The cuff  13  shown is of a high pressure kind made of an elastic material that lies close to the shaft  10  when deflated and is stretched outwardly when inflated. The shaft  10  and cuff  13  are both moulded of a silicone material. It will be appreciated that the tube could be of a different sizes, shapes and materials according to the application. 
     The machine end  14  of the shaft  10  is adapted, during use, to be located externally of the tracheostomy opening formed in the patient&#39;s neck. The machine end  14  of the shaft  10  is bonded into a hub or connector  15  having a conventional 15 mm male tapered outer surface  16 . The connector  15  is adapted to make a removable push fit in a conventional 15 mm female connector (not shown) at one end of a breathing tube extending to a ventilator or anaesthetic machine. Alternatively, the machine end of the tube  1  could be left open to atmosphere when the patient is breathing spontaneously. The tracheostomy tube  1  also includes a radially-extending support flange  20  adapted to lie against the skin surface of the neck on either side of the tracheostomy stoma. The flange  20  is moulded integrally as one part with the shaft  10  at its machine end  14  or may be formed separately. The flange  20  has openings  21  at opposite ends for attachment to a neck strap (not shown) used to support the tube with the patient&#39;s neck. 
     The shaft  10  also includes an inflation line  31  in the form of a small-bore tube secured in a channel  32  extending along the outside of one side of the shaft. The inflation line  31  has an opening  33  towards its patient end located approximately midway along the length of the sealing cuff  13 . The machine end of the inflation line  31  extends through the flange  20  and continues unattached with the shaft  10  being joined with and extending into one end  36  a conventional inflation indicator  37 . The inflation indicator  37  includes a flat, flexible envelope or balloon  38  into which the inflation line  31  opens so that the balloon is inflated or deflated according to the inflation state of the sealing cuff  13 . The opposite end of the inflation indicator balloon  38  is bonded to one end of the outside of a rigid connector sleeve  39  containing a valve (not visible in the drawing) and being open at its machine end  40  to receive a male coupling such as the nose of an inflation syringe. 
     As so far described the tracheostomy tube assembly is conventional. The assembly differs from conventional tracheostomy tubes by the addition of a protector enclosure  50  adapted to extend around and enclose the inflation indicator  37  to protect it from damage by chewing. 
       FIGS. 2 to 4  show the inflation indicator  37  before and after assembly of the protector enclosure  50  onto the inflation indicator  37 . The enclosure  50  consists of two main parts. The first, machine-end part or base  51  is a moulding of a semi-rigid, opaque plastics material, such as having a Shore D hardness of about  50 . The base  51  has a circular section with a waisted central region  52  formed with flats  53  around its circumference to improve the grip on the enclosure  50  between finger and thumb. The machine end  54  of the base  51  is open so that the machine end  40  of the inflation indicator  37  is accessible for inflation or deflation. At its opposite, patient end  55  the outer surface of the base  51  is formed with two opposite locking formations or notches  56  and  57 . 
     The protector enclosure  50  is completed by a second part  60  in the form of a transparent cylindrical sleeve. The sleeve  60  is moulded of a stiff, transparent plastics material and is circular in section with an open machine end  62  having an outwardly projecting annular rim  63  the external diameter of which is such that it snaps into an internal retaining groove (not shown) around the inside of the base  51 . The patient end  64  of the sleeve  60  is closed apart from a small opening  65  just large enough to receive the inflation line  31 . The sleeve  60  also has two diametrically opposite slots  66  and  67  extending longitudinally of the sleeve. One slot  66  opens at its machine end into the open machine end  62  of the sleeve  60  and opens at its opposite end into the small patient-end opening  65  of the sleeve. The other slot  67  is shorter and terminates before the machine end opening  62  and the patient end opening  65 . The longer slot  66  enables the sleeve  60  to be slid onto the inflation line  31  sideways and also gives the sleeve some resilience so that it can be squeezed to reduce the diameter at its machine end  62  and enable this to be inserted into the patient end of the base  51 . The sleeve  60  also has two locking features  68  and  69  on opposite sides of its outer surface, midway between the two slots  66  and  67  and about half way along the length of the sleeve. The locking features  68  and  69  are shaped to clip onto the two notches  56  and  57  on outside of the base  51 . Engagement of the locking features  68  and  69  on the sleeve  60  with the notches  56  and  57  on the base  51  prevents the sleeve rotating relative to the base. 
     The protective enclosure  50  could be permanently fitted onto the inflation indicator  37  by applying a bonding agent to the machine end of the sleeve  60  so that it becomes securely and permanently bonded to the base part  51 . Alternatively, the sleeve  61  need not be bonded to the base  51  so that the protector  50  can be removed from the inflation indicator  37  when necessary. 
     The protector enclosure  50  is fitted on the inflation indicator  37  by first sliding the inflation line  31  sideways through the long slot  66  of the sleeve  61  at a location spaced a short distance away from the inflation balloon. The sleeve  61  is then oriented so that the opposite slots  66  and  67  align with the edges of the inflation balloon  38 . The sleeve  61  can then be threaded rearwardly along the inflation line  31  and along the outside of the inflation indicator  37  as far as it will go. The assembly of the inflation indicator  37  and sleeve  61  is then slid rearwardly into the patient end of the base  51 , aligning the locking features  68  and  69  on the sleeve with the notches on the base. The sleeve  61  is squeezed at the same time to compress the slots  66  and  67  so as to enable the rim  63  to enter the base  51  and then open into the internal retaining groove when released. Instead of loading the sleeve  61  onto the inflation indicator  37  first it would be possible to insert the inflation indicator into the base first and then slide the sleeve over and along the inflation indicator into the base. 
     With the inflation indicator  37  contained within the protective enclosure  50  the balloon  38  can inflate and deflate in the usual manner and the state of inflation of the indicator can be viewed through the transparent sleeve  60 . If the child patient should chew on the assembly, the inflation indicator  37  will not be damaged because it is protected by the protector  50 . 
     The protector  50  can be readily fitted to a conventional inflation indicator of a tracheostomy tube without the need for any special tools. The protector could be provided separately of the tracheostomy tube and assembled on the inflation indicator by the user, if needed. The protector need not be fitted by a clinical specialist but can be fitted by a child&#39;s carer at home as needed. 
     The protector could be provided with features specifically designed for the patient to chew so that he does not chew other parts of the protector. One example of a protector  150  with such features is shown in  FIGS. 5 and 6  where the base  151  is integrally moulded with two projecting chew flanges  180  and  181 . The flanges  180  and  181  are substantially flat and circular with three small protrusions  182  and  183  spaced around their edge. Both flanges  180  and  181  project outwardly of the base  151 . One flange  180  has an axis normal to its plane extending parallel to the axis of the base  151 . The other flange  181  has an axis normal to its plane extending orthogonally to the axis of the base  151 . The patient can easily chew on these flanges  180  and  181  without causing any damage to the inflation indicator.