Abstract:
A flexible connector couples the inlet end of a tracheotomy tube inner cannula to an outlet port of an in-line catheter. The catheter exit end of the connector is adapted to be serially coupled in pneumatic communication with the inlet end of the tracheotomy tube inner cannula and also to guide the downstream tip of the catheter into the inlet end of the inner cannula in response to pushing of the catheter upstream of the catheter outlet port. Thus, the in-line catheter can be inserted into the tracheotomy tube inner cannula with little likelihood of having to compress or “flip” the connector or disconnect the connector from the tracheotomy tube and the patient from the ventilator circuit.

Description:
BACKGROUND OF THE INVENTION 
     This invention relates generally to tracheotomy associated equipment and more particularly concerns flexible connectors for coupling in-line catheters to tracheotomy tube inner cannulas. 
     In-line suction catheters are used to permit a patient to continuously respirate through a tracheotomy tube while the catheter is inserted into the inner cannula of the tracheotomy tube. The in-line catheter has a housing with two inlet ports and an outlet port. A ventilator circuit is connected to one of the housing inlet ports. The catheter extends into the housing through the other housing inlet port. A flexible connector couples the housing outlet port in serial communication with the inlet or ventilator end of the inner cannula. The air and catheter are pushed through the flexible connector into the inlet end of the cannula for administration to the patient. The flexible connector consists of an accordion-like tubular body with entry and exit collars on its respective ends taken in relation to the direction of insertion of the catheter. The exit end of the flexible connector slips onto the entry end of the inner cannula and the entry end of the flexible connector slips into the outlet port of the in-line catheter housing. 
     In-line suction catheters, as they are inserted through known flexible connectors into the entry end of the inner cannula, almost always hang up on the inlet face of the insertion end of the cannula. This interference necessitates immediate implementation of one or more remedial actions until the problem is resolved. Initially, the flexible connector is longitudinally compressed to decrease the length between the tip of the in line suction catheter and the ventilator end of inner cannula. If compression does not resolve the problem, the suction catheter is twisted and turned in an attempt to “flip” it into the entry to the inner cannula. These actions cause discomfort to the patient, lengthen the time required for completion of the procedure, waste the valuable time of respiratory therapists and nurses and expend possibly precious time for the patient undergoing the procedure. 
     If neither compression nor “flipping” are successful, the inline suction catheter is eventually disconnected from the ventilator circuit. In this case, the procedure is further lengthened by the extra time to needed to disconnect and reassemble the ventilator circuit. More significantly, disconnection causes a loss of ventilator pressure to the patient which can be rapidly physiologically catastrophic, cause a loss of sterility possibly resulting in more infections and further subject the patient to more stressful discomfort including the experience of a “smothering” feeling from no longer being on the ventilator. Furthermore, some patients require the pressure created by the ventilator circuit to keep their airways free of fluid and allow oxygenation/ventilation to occur. Once pressure is lost, the procedure has embarked on down hill course. A disconnect from the pressure of the ventilator circuit can result in rapid “flooding” of the alveoli with fluid, resulting in extremely quick decompensation, perhaps in as little as the time for eight breaths. When the ventilator circuit is reconnected, it can take several hours for the regained pressure to clear the alveoli of fluid. For patients who are dependent on maintenance of continued pressure, it is imperative that no disconnects occur as the benefits of loss of pressure are quickly lost and slowly regained. 
     In a worst case scenario, once the connector has been removed and the in-line suction catheter has been placed directly on the inner cannula, the catheter may still hang up on the cannula entry face. In this event, it is necessary to acquire from supply and install a different type of suction catheter which can be passed directly into the inner cannula entry, leaving the patient completely off the ventilator and increasing the time and expense of the procedure and the risks and discomfort to the patient. 
     It is, therefore, an object of this invention to provide a flexible connector which facilitates easy passage of an inline suction catheter into a tracheotomy tube inner cannula. Another object of this invention is to provide a flexible connector which does not require longitudinal compression to accomplish passage of an inline suction catheter into a tracheotomy tube inner cannula. A further object of this invention is to provide a flexible connector which, even when arcuately flexed, will readily pass an inline suction catheter into a tracheotomy tube inner cannula. Yet another object of this invention is to provide a flexible connector which does not require twisting and turning of the suction catheter to “flip” the catheter into the inner cannula. It is also an object of this invention to provide a flexible connector which reduces the likelihood of need to disconnect the patient from the ventilator to accomplish passage of a catheter into a tracheotomy tube inner cannula. 
     SUMMARY OF THE INVENTION 
     In accordance with the invention, a flexible connector is provided for coupling the inlet end of a tracheotomy tube inner cannula to an outlet port of an in-line catheter. The connector has an elongated, flexible, accordion-like tubular body. The catheter entry end of the tubular body is adapted to be serially coupled in pneumatic communication with the catheter outlet port. The catheter exit end of the tubular body is adapted to be serially coupled in pneumatic communication with the inlet end of the tracheotomy tube inner cannula and to guide the downstream tip of the catheter into the inlet end of the inner cannula in response to pushing of the catheter upstream of the catheter outlet port. 
     In a preferred embodiment of the connector, the guiding adaptation is a gradual taper in a downstream direction. The taper has an inner diameter at its upstream end substantially equal to the outer diameter of the inlet end of the inner cannula and an inner diameter at its downstream end not greater than the inner diameter of the inlet end of the inner cannula. A flat wall is provided about the downstream end of the gradual taper. The wall has a thickness substantially equal to the thickness of the entry end face of the inner cannula. A portion of constant diameter extends downstream from the flat wall and cooperates with the flat wall to form a cup for the entry end of the inner cannula. When the inner cannula is inserted into abutment against the flat wall of the cup, the diameter of the downstream passageway of the taper is not greater than the diameter of the passageway into the abutting cannula, so a catheter cannot “hang up” on the cannula. 
     It is also preferred that the exit end of the connector have a bearing portion with an outer diameter substantially equal to the outer diameter of the cup. The bearing portion extends upstream from the upstream end of the gradual taper. A hard sleeve concentrically disposed about and spanning across the bearing portion and the cup creates a void between the sleeve and the connector, but the bearing portion and cup afford sufficient contact to enable manipulation of the exit end of the connector by manipulation of the hard sleeve. A radial expansion at the upstream end of the bearing portion and an annular rim on the downstream end of the cup cooperate to prevent longitudinal motion of the sleeve on the connector. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Other objects and advantages of the invention will become apparent upon reading the following detailed description and upon reference to the drawings in which: 
         FIG. 1  is a longitudinal diametric cross-sectional view of a known flexible connector with a catheter inserted therein; 
         FIG. 2  is a cross-sectional view taken along the line  2 - 2  of  FIG. 1 : 
         FIG. 3  is a side elevation view of a preferred embodiment of a flexible connector in accordance with the invention; 
         FIG. 4  is a cross-sectional view taken along the line  4 - 4  of  FIG. 3 ; 
         FIG. 5  is a cross-sectional view taken along the line  5 - 5  of  FIG. 3 ; 
         FIG. 6  is a side elevation assembly view of the flexible connector of  FIG. 3  with a hard sleeve at the entry end of the connector and the entry end of a tracheotomy tube inner cannula at the exit end of the connector; 
         FIG. 7  is a longitudinal diametric cross-sectional view of the assembled components of  FIG. 6  with a catheter inserted in the flexible connector; 
         FIG. 8  is a cross-sectional view taken along the line  8 - 8  of  FIG. 7 ; and 
         FIG. 9  is a longitudinal diametric cross-sectional view of the assembled components of  FIG. 6  with a hard sleeve mounted on the exit end of the connector. 
     
    
    
     While the invention will be described in connection with a preferred embodiment thereof, it will be understood that it is not intended to limit the invention to that embodiment or to the details of the construction or arrangement of parts illustrated in the accompanying drawings. 
     DETAILED DESCRIPTION 
     Turning first to  FIGS. 1 and 2 , a typical known flexible connector  10  is illustrated. The connector  10  is commonly used to couple the inlet end of a tracheotomy tube inner cannula  11  to the outlet port of an in-line catheter (not shown). The cannula  11  has a soft inner liner  12  and a hard outer case  13  which terminate at a relatively thick inlet face  14 . The connector  10  has an elongated, flexible, accordion-like tubular body  15 . The catheter entry end  16  of the tubular body is adapted to be serially coupled in pneumatic communication with the catheter outlet port (not shown). The catheter exit end  17  of the tubular body  15  is adapted to be serially coupled in pneumatic communication with the inlet end of the tracheotomy tube inner cannula  11 . The entry and exit ends  16  and  17  of the connector body  15  are fitted with hard sleeves  18  and  19  with outer annular flanges  21  and  22 , respectively. The sleeves  18  and  19  and flanges  21  and  22  are helpful in manipulating the connector  10  which, by reason of its size and configuration and its contact during use with fluids which make its surface extremely slippery, can be quite awkward. 
     As best seen in  FIG. 1 , the tip  23  of the catheter  24  has been inserted serially into the entry end  16 , body  15  and exit end  17  of the connector  10  until the tip  23  is in close proximity to the inlet face  14  of the inner cannula  11 . As shown, even when the connector  10  is perfectly aligned along its longitudinal axis  25 , the catheter  24  tends to bow under its own weight so that, as best seen in  FIG. 2 , the tip  23  at least partially aligns longitudinally with the entry face  14  of the inner cannula  11 . Further insertion of the catheter  24  into the connector  10  will cause the tip  23  to “hang up” on the cannula face  14 , blocking passage of the catheter  24  into the cannula  11  and initiating the sequence of undesirable events and consequences hereinbefore discussed. Considering that the intended purpose of the design of the connector  15  is to permit it to be stretched, compressed and bent and that the catheter  24  must also be sufficiently flexible to travel a somewhat tortuous path, it is unlikely that the catheter tip  23  will not “hang up” on the cannula face  14 , as has been evidenced in practice for many years. 
     Looking now at  FIGS. 3-5 , a preferred embodiment of a flexible connector  30  according to the invention is illustrated. The new flexible connector  30 , like its predecessor connector  10 , has an elongated, flexible, accordion-like tubular body  35  with its catheter entry end  36  and its catheter exit end  37  adapted to be serially coupled in pneumatic communication with the catheter outlet port (not shown) and with the inlet end of the tracheotomy tube inner cannula  11  seen in  FIGS. 1 and 2 , respectively. However, the catheter exit end  37  of the body  35  is modified to guide the downstream tip  23  of the catheter  24  into the inlet end of the inner cannula  11  in response to pushing of the catheter  24  at a point upstream of the catheter outlet port (not shown). 
     In the preferred embodiment of the connector  30  shown, and following the contour of the catheter exit end  37  of the body  35  in a downstream direction, a taper  41  expands the exit end  37  to a maximum outer diameter  43  greater than outer diameter  26  of the entry end of the inner cannula  11 , as seen in  FIG. 1 . The maximum outer diameter  43  is then contracted to form an annular stop  45  on the outer surface of the exit end  37 , the outer diameter  47  of the exit end  37  being substantially equal to the outer diameter  26  of the entry end of the inner cannula  11 . The exit end  37  then has a gradual taper  49  to an inner diameter  51  which is substantially equal to the inner diameter  27  of the entry face  14  of the inner cannula  11 . The exit end  37  of the connector  30  then radially expands to an inner diameter  53  substantially equal to the outer diameter  26  of the entry end of the inner cannula  11 , forming a flat downstream wall  55  of thickness  57  substantially equal to the thickness  28  of the inner cannula entry face  14 , as seen in  FIG. 1 . The exit end  37  of the connector  30  extends downstream from the wall  55  at a constant inner diameter  53  and terminates at an annular rim  59 . 
     Looking at  FIGS. 6-8 , the entry end  36  of the connector  30  is similar in all respects to the entry end  16  of the known connector  10  seen in  FIG. 1 . Its inner diameter  61  is sized to receive the downstream end of the outlet port of the catheter housing (not shown). Its outside diameter  63  is sized to be inserted into the entry hard sleeve  18  and an annular stop  65  is positioned on its outer surface to engage an annular seat  29  in the sleeve  18 . The seat  29  and stop  65  are positioned to prevent axial motion of the sleeve  18  on the connector  30  when the downstream end of the sleeve  18  abuts the proximal accordion surface of the body  35 . 
     Continuing to look at  FIGS. 6-8 , the downstream portion of the exit end  37  of the connector  30  defined by the constant inner diameter  53  and the wall  55  form a cup  67  for receiving the entry end of the inner cannula  11 . The inner cannula  11  is inserted into the cup  67  until the cannula entry face  14  abuts the connector wall  55 . When the catheter  24  is inserted serially into the entry end  36 , body  35  and exit end  37  of the connector  30  until the tip  23  is in close proximity to the inlet face  14  of the inner cannula  11 , the gradual taper  49  leading up to the cup  67  guides the downstream tip  23  of the catheter  24  into the inlet end of the inner cannula  11  in response to further pushing of the catheter  24  from a position upstream of the catheter outlet port (not shown), as is best seen  FIG. 7 . Thus, when the cannula face  14  and the connector wall  55  are in abutment, the catheter tip  23  cannot “hang up” on the entry face  14  of the inner cannula  11 , as is best seen in  FIG. 8 . This is true whether the connector  30  is straight, stretched, compressed or bent. 
     Turning to  FIG. 9 , the outer diameters  47  and  69  at the stop  45  and of the cup  67 , respectively, are substantially equal. Therefore, the hard sleeve  19  can be fitted on these constant diameter portions and used to manipulate the exit end  37  of the connector  30  even though the gradual taper  49  creates an annular void  71  between the connector  30  and the hard sleeve  19 . 
     The connector  30  has been described in relation to an inner cannula  11  of a tracheotomy tube having inner and outer cannulae. Some tracheotomy tubes have a single cannula which, for purposes of using the modified cannula  30 , may be considered as the inner cannula herein discussed. 
     Thus, it is apparent that there has been provided, in accordance with the invention, a flexible connector that fully satisfies the objects, aims and advantages set forth above. While the invention has been described in conjunction with a specific embodiment thereof, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art and in light of the foregoing description. Accordingly, it is intended to embrace all such alternatives, modifications and variations as fall within the scope of the appended claims.