Abstract:
Disclosed herein is a novel tube-in-tube endotracheal tube apparatus that allows for replacement or cleaning of an inner (first) tube without having to re-intubate the patient. The novel endotracheal tube apparatus enables the application of continuous suction or intermittent suction. The endotracheal device also serves to decrease the incidence of ventilator-associated pneumonia (VAP).

Description:
FIELD OF THE INVENTION  
         [0001]    The present invention relates to a novel endotracheal tube apparatus and methods of using the same, and more specifically, a multiple lumen endotracheal tube device including a tube within a tube arrangement constructed to permit the inner tube to be removed from the outer tube by a removable connector and replaced by a new sterilized inner tube to reduce the risk of ventilator-associated pneumonia.  
         BACKGROUND OF THE INVENTION  
         [0002]    Ventilation is the physiologic process which supplies oxygen to the body and removes carbon dioxide, a gaseous waste product. Normally, ventilation is provided from the cyclic flow of gas into and out of the lungs. The flow results from the contraction and relaxation of the diaphragm. Many surgical and critical care patients are unable to ventilate adequately, and ventilation must be provided mechanically using a mechanical ventilator and a single lumen endotracheal tube. An endotracheal tube (ETT) typically is comprised of a lumen or tube that is open at both ends, and has a comfort cuff or balloon positioned at one end. An ETT is positioned in the mid trachea whereby it acts as a conduit for gas from the ventilator to the lungs.  
           [0003]    Patients who are critically ill or who have undergone surgical procedures require mechanical ventilation to sustain life. Patients that require mechanical ventilation for prolonged periods of time often develop a potentially fatal condition called ventilator-associated pneumonia or VAP. VAP is caused by bacteria build up in the moist environment on the ventilation tubing apparatus and infects the patient&#39;s lungs.  
           [0004]    VAP is a major threat to the recovery of patients receiving mechanical ventilation, and is the most lethal infection in mechanically ventilated patients. VAP was the most frequent nosocomial infection aquired in ICUs in Europe, accounting for 45 percent of all infections. J L Vincent, D J Bihari, P M Suter, H A Bruining, J White, M H Nicolas-Chanoin, M Wolff, RC Spencer, M Hemmer: The prevalence of nosocomial infection in intensive care units in Europe. Results of the European Prevalence of Infection in Intensive Care (EPIC) Study.  J Am Med Assoc  1995, 278: 639-644. The early and accurate diagnosis of VAP is difficult, but because of the increasing prevalence of multi-resistant pathogens in many ICUs; it constitutes an urgent challenge. It is especially difficult to distinguish VAP from other causes of fever and infection. A fatal outcome is frequently observed in patients who are mechanically ventilated for more than 48 hours. Several investigators have hypothesized that VAP has a direct causal influence on mortality. J Y Fagon, J Chastre, A J Hance, P Montravers, A Novara, C Gibert: Nosocomial pneumonia in ventilated patients: a cohort study evaluating attributable mortality and hospital stay,  Am J Med  1993, 94: 281-288.  
           [0005]    VAP can make a patient ill for a very long time or even cause death in critically ill patients, especially in infants and the elderly. In order to prevent or lessen the threat of VAP, health care professionals repeatedly re-intubate patients that require ventilation over long periods of time. Accordingly, there is a need in the art for an endotracheal tube apparatus designed for prolonged ventilation, which aids in preventing the VAP. Embodiments of the invention described herein utilize a unique tube in tube endotracheal tube design that provides for ventilation and suctioning. The tube in tube arrangement also allows for replacement of the ventilation tube of the endotracheal tube to prevent bacterial build up that can cause VAP.  
           [0006]    Furthermore, the shape of the distal ends of current tracheal tubes can cause extensive damage to tracheal during intubation. A less intrusive tubal design would be desirous to reduce the injury and damage caused by the process of intubing a patient.  
         SUMMARY OF THE INVENTION  
         [0007]    The present invention relates to a novel endotracheal tube apparatus including at least two tubes where one tube is inserted within the other tube to form a “tube-in-a-tube” structure. The subject ETT provides the ability to apply suction and be cleaned or replaced without damaging a patient&#39;s trachea.  
           [0008]    It is an object of the present invention to provide an endotracheal tube apparatus that includes at least two tubes where the first tube is inserted into the second tube so that the first tube can be disposed of and replaced by another sterilized first tube to reduce the risk of ventilator-associated pneumonia.  
           [0009]    It is another object of the present invention to provide an endotracheal tube apparatus having the distal ends of the second tube shaped such that the ends curve inward to reduce tracheal injury.  
           [0010]    It is a further object of the present invention to provide an endotracheal tube apparatus having the distal ends of the second tube shaped such that the ends curve inward to direct secretions between the tubes to the suction port.  
           [0011]    It is still a further object of the present invention to provide an endotracheal tube apparatus that is constructed of a hydrogel material to prevent adherence to tracheal tissue of the patient.  
           [0012]    It is still another further object of the present invention to provide an endotracheal tube apparatus that is constructed of a hydrogel material inhibiting the build-up of bacteria which cause ventilator-associated pneumonia.  
           [0013]    Still yet another aspect of the present invention relates to an endotracheal tube apparatus where the inner wall of the second tube or the outer wall of the first tube is provided with raised structures such as ribbed structures to form a channel between the first and second tube for suctioning to reduce the risk of ventilator-associated pneumonia. Preferably, the endotracheal tube apparatus has a multiple part connection at the proximal end. The multiple part connection is configured such that the inner (first) tube is responsible for ventilation and can be removed, cleaned, or disposed of and replaced while the patient remains intubated by the outer (second) tube. The subject ETT apparatus reduces the tissue damage to the trachea and surrounding areas, by overcoming the need for repeated re-intubation.  
           [0014]    The foregoing has outlined some of the more pertinent objectives of the present invention. These objectives should be construed to be merely illustrative of some of the more prominent features and applications of the invention. Many other beneficial results can be attained by applying the disclosed invention in a different manner of modifying the invention as will be described.  
           [0015]    It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not to be viewed as being restrictive of the present invention, as claimed. These and other objects, features and advantages of the present invention will become apparent after a review of the following detailed description of the disclosed embodiments and the appended claims. For example, although less preferred, those skilled in the art will appreciate that the subject apparatus could be configured such that suction occurs in the inner tube and ventilation occurs via the channel between the inner and outer tubes. 
       
    
    
     DESCRIPTION OF THE DRAWINGS  
       [0016]    [0016]FIG. 1 illustrates a cross-sectional side view of an embodiment of the endotracheal tube apparatus showing the first and second connectors and the first and second tube arrangement according to the present invention.  
         [0017]    [0017]FIG. 2 illustrates an enlarged cross-sectional side view of the proximal end of the endotracheal tube apparatus showing the first and second connectors and where the first and second tubes are secured onto the connectors according to the present invention.  
         [0018]    [0018]FIG. 3 is taken along the plane  3 - 3  of FIG. 2 as an enlarged cross-sectional view of a concentric tube arrangement showing a preferred arrangement of the raised structure(s) being formed as part of the outer wall of the first tube according to the present invention.  
         [0019]    [0019]FIG. 4 is taken along the plane  4 - 4  of FIG. 5 and illustrates an enlarged cross-sectional view of an embodiment of double lumen endotracheal tube apparatus showing a preferred arrangement of the first and second lumens according to the present invention.  
         [0020]    [0020]FIG. 5 illustrates a cross-sectional side view of an embodiment of the double lumen endotracheal tube apparatus showing a preferred arrangement of the first and second lumen according to the present invention.  
         [0021]    [0021]FIG. 6 illustrates an alternative embodiment of the present invention showing a second suction channel for subglottic secretion drainage during intubation according to the present invention. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0022]    The present invention relates to a novel endotracheal tube apparatus  10  including at least two tubes  20  and  26  where the first tube  26  is inserted within the second tube  20  to form a “tube-in-a-tube” structure. The ETT preferably, but not necessarily, forms a concentric arrangement (shown in FIG. 1). At least two connectors are included in the subject invention where the first 14 and 16 second connectors are removeably attachable and dimensioned and configured to interconnect with one another. The second connector  16  may have two ports, one port  40  being dimensioned and configured to be attached to the proximal end of the second tube  20  and the other port  34  being removeably attached to a suction apparatus. The first connector  14  includes two ports, one port  38  being removeably attached to the proximal end  18  of the first tube and another port  36  being removeably attached to a ventilation device. The first connector  14  can be removeably attached from the second connector  16  during mechanical ventilation of a patient, and preferably, at least one inflatable cuff  28  to be inflated which is illustrated in FIGS. 1 and 2. As an alternative embodiment, the connections may be integral to the tubes as opposed to attached to the ends of the tubes. Either the outer wall of the first tube  26  or the inner wall of the second tube  20  may be provided with raised structures such as ribs, rod-like structures, bubbled structures, or the like  24  which form a first suction channel  22  between the walls of the two tubes  20  and  26 . The distal end  42  of the second tube  20  is preferably shaped so that the ends  32  curve inwards to reduce tracheal damage and to direct secretions into the first suction channel  22 .  
         [0023]    According to one embodiment, as shown in FIGS. 1 and 2, the present invention is an endotracheal tube apparatus  10  comprising at least two elongated tubes each having a proximal  18  and distal end  42 , wherein a first tube  26  is removeably inserted inside the length of a second tube  20 , the first tube  26  includes an inner and outer wall and the second tube  20  includes an inner and outer wall; and at least two connectors where the first  14  and second  16  connectors are removeably attachable and dimensioned and configured to interconnect with one another. The second connector  16  may comprise one or more ports. One port  40  being dimensioned and configured to be attached to the proximal end  18  of the outer tube  20  and another port  34  being removeably attached to a suction apparatus. The first connector  14  comprises two ports. One port  38  being removeably attached to the proximal end  18  of the first tube  26  and another port  36  being removeably attached to a ventilation device. The first connector  14  can be removeably attached from the second connector  16  during intubation of a patient.  
         [0024]    In a preferred embodiment, the inner wall of the second tube  20  or the outer wall of the first tube  26  includes raised structures  24  to form a first suction channel  22  throughout the length of the apparatus between the elongated tubes  20  and  26 . Alternatively, the raised structures  24  could be hollow, thus allowing distal airway pressure recording, suction, and illumination fibers.  
         [0025]    The first tube  26  can be advanced or retracted with respect to proximal end  18  of elongated second tube  20 . The first  26  and/or second  20  tubes of the endotracheal tube apparatus  10  are preferably constructed of a hydrogel-like material to reduce the risk of microbe build up, which may result in complications including ventilator-associated pneumonia. The first tube  26  and/or second  20  tube of the endotracheal tube are preferably constructed of or coated with a conventional pliable plastic such as polyvinyl chloride (PVC), polyurethane, fluroplastic, polyester, nylon, polypropylene and silicone plastic. However in a more preferred embodiment, the first tube  26  is constructed of a pliable plastic and the second tube is partially or completely constructed of a hydrogel material.  
         [0026]    In a preferred embodiment, the distal end  42  of the second tube  20  is shaped so that the end  32  curves inwards to reduce tracheal injury and to direct secretions in the first suction channel  22 . The endotracheal apparatus  10  also includes an inflatable cuff  28 . There are many types and designs of inflatable cuffs or balloons that are known in the art and any of those can be incorporated into the present invention  10 . Preferably, the inflatable cuff  28  can be secured onto the distal end  42  of the outer wall of the second tube  20 . However, variations of cuff operations and integrations that are known in the art of endotracheal tube apparatuses can be incorporated into the present invention. The cuff may be made from a conventional elastomeric material such a latex, polyurethane, PVC, silicone rubber or silicone plastic. The leading and trailing ends of cuff may be attached to elongated member or tube at cuff attachment points using a conventional non-brittle, medical grade adhesive. The cuff preferably forms an elliptical shape when interior of the cuff is inflated via an air supply that communicate with an inflation lumen in the tube.  
         [0027]    The first suction channel  22  that is formed by the raised structures  24  on the wall which are secured or part of either the first tube  26  or second tube  20  and preferably runs throughout and between the entire length of both tubes  20  and  26  and allows for suction while the patient is intubated to remove gases and secretions and also to reduce the risk of ventilator-associated pneumonia. FIG. 3 shows a preferred embodiment of the endotracheal tube apparatus  10  having the ribbed structure(s)  24  as part of the outer wall of the first tube  26 . When the first tube  26  with ribbed structure(s)  24  is removed, any bacterial build-up on the ribbed surface  24  would be removed and to allow suction. In an alternative embodiment, as shown in FIG. 6, at least one flexible outer sleeve  15  with a second suction channel  19  or second suction channel that is integrated into the endotracheal tubing extends along the outer tubing and opens through an orifice  21  above the inflated cuff  28 . The second suction channel  19  is designed for subglottic secretion drainage during intubation. Suction as applied to the second suction channel  19  as an opening (not shown) at the proximal end of the subject endotracheal tube.  
         [0028]    The connectors  14  and  16  of the endotracheal tube apparatus  10  are preferably formed by injection molding and may be removeably replaced while the patient is still intubated. The connectors  14  and  16  can be disposable or treatable through sterilization or other methods known in the art of cleaning medical equipment. The endotracheal tube apparatus  10  is constructed and structured to provide long term intubation of a patient needing ventilation by permitting the outer tube to remain in the patient&#39;s trachea while removing the first tube  26  to be cleaned or replaced by another first tube  26  which is reinserted through the length of the second tube  20  and reattached to the first connector  14  and is positively locked into the second connector  16 .  
         [0029]    Another embodiment of the present invention  10  includes a method of intubation which comprises inserting the distal end  42  of the second tube  20  into the lungs of a patient in need of ventilation. The first tube  26  is inserted into the second tube  20 , and the first  14  and second  16  connectors are interconnected. A ventilator apparatus is connected to the first connector  14 , and a suction device is connected to the second connector  16 . Continuous or intermittent low vacuum suction is applied through the first suction channel  22 . At a predetermined interval, the first tube  26  is removed and cleaned or replaced with another first tube  26  while patient is still intubated with the second tube  20 .  
         [0030]    The present invention  10  includes several aspects where the first  26  and second  20  tubes are constructed of a combination of a hydrogel and/or of conventional pliable plastic such as polyurethane, PVC, fluroplastic, polyester, nylon, polypropylene and silicone plastic, or any combination thereof.  
         [0031]    The endotracheal tube apparatus  10  is constructed of materials that provide a hostile (non-ideal) surface for bacteria to form colonies. Since it take a considerably longer time for bacteria and other known infectious organisms to build-up on these hostile surfaces, long term intubation is safer. The distal portion  42  of the second tube  20  including the cuff  28  are manufactured of a hydrogel material which is not a suitable surface for bacteria to secrete substances that allow them to adhere, form colonies, and protect themselves from antibiotics. The cuff  28  also includes a hydrogel sleeve  44  to additional aid in reducing the risk of ventilator-associated pneumonia because it too provides a hostile surface for bacteria growth.  
         [0032]    The operation of the endotracheal tube apparatus  10  starts with the insertion of either the second tube  20  or both first  26  and second  20  tubes into the lungs of a patient. A suction device is attached to one of the connectors  16  that function as a suction port where a continuous suction flow is supplied. The outer cuff  28  is inflated or the inner cuff (not shown) is inserted and inflated to a predetermined target area within the patient&#39;s lungs. The first suction channel  22  formed by the raised structures (see FIG. 3) permits gas to pass upwards to both expire unwanted CO 2  and to prevent further seeding of bacteria. The inner cuff (not shown) can be removed and the connector  14  and first tube  26  is removeably attached and the new first tube  26  is attached to the connector  14  and once again the connector  14  with new first tube  26  is positively locked into the other connector  16  while the endotracheal apparatus  10  is still intubated within the patient. The two removeably and positively locked connectors  14  and  16  and the first  26  and second  20  tubes may be in a concentric arrangement having a tube within a tube construction where the first tube  26  is removeably insertable while the endotracheal apparatus  10  (second tube  20 ) remains in place within the patient&#39;s lungs. The operation of the endotracheal tube apparatus  10  may vary in the order of steps and procedures described above.  
         [0033]    Thus, it can be appreciated that the present endotracheal tube apparatus  10  is ideal for long term use. The average surgeon would find that the double lumen endotracheal apparatus  10  is much easier to utilize than the very difficult or impossible current endotracheal tubes. The present invention allows the average clinician to place the endotracheal tube apparatus  10  using average clinical skills in a timely, nonproblematic fashion with minimal trauma to the airway.  
         [0034]    It will be readily understood by those skilled in the art that the general concept of the invention can be adapted for implementation into conventional double lumen endotracheal tubes. By way of background, in thoracic surgery, the chest wall is incised, the lung opened and the pleural space entered. As a result, the lung will collapse, and ventilation can escape. The ventilation to the non-operative lung must be isolated before opening the operative lung segment. The risk of patient harm exists if ventilation is not isolated before beginning thoracic surgery. This results from the escape of ventilation through the surgical lung opening. Isolation of ventilation is commonly required in medical patients. A portion of the lung can be diseased and requires isolation from mechanical ventilation. Conditions which require isolation are infection of the lung (pneumonia); bleeding in the lungs (hemoptysis); and a non-surgical opening into the pleural space (pneumothorax).  
         [0035]    Double lumen endotracheal tubes are commercially available to achieve isolation of ventilation but are constructed to temporarily intubate a patient in need of ventilation. Double lumen endotracheal tubes available today are made of two endotracheal tubes fused together of unequal length. They incorporate two balloons, one balloon which envelopes the tracheal position of the two fused endotracheal tubes (the tracheal balloon) and a second which envelopes the longer portion and will extend into either the right or left mainstem bronchus (the bronchial balloon). A double lumen tube will isolate ventilation when positioned correctly with the longer portion in the right or left mainstem bronchus, and when both balloons are inflated.  
         [0036]    There are disadvantages in using current double lumen endotracheal tubes. Double lumen endotracheal tubes are larger in diameter and longer than conventional endotracheal tubes and can damage the vocal chords and the nerves for the vocal chords. The left mainstem bronchus is difficult to enter with the longer portion. In patients where the normal airway anatomy is altered, the use of double lumen endotracheal tubes has caused patient harm. Due to the complexity and size, hypoxic brain damage has occurred because of the time needed to correctly place the device in the airway. Double lumen endotracheal tubes are only intended for temporary use because if left in place for long periods of time, they can cause damage to the tracheal bronchial tree including disruption.  
         [0037]    According to an alternative embodiment, as shown in FIGS. 4 and 5, the subject invention is directed to a double lumen endotracheal tube  50  having at least two connectors are included in the subject invention where the first  14  and  16  second connectors are removeably attachable and dimensioned and configured to interconnect with one another. The second connector  16  may have two ports, one port  40  being dimensioned and configured to be attached to the proximal end of the second tube  20  and the other port  34  being removeably attached to a suction apparatus. The first connector  14  includes two ports, one port  38  being removeably attached to the proximal end  18  of the first tube and another port  36  being removeably attached to a ventilation device. The first connector  14  can be removeably attached from the second connector  16  during mechanical ventilation of a patient, and preferably, at least one inflatable cuff  28  to be inflated. The second tube  20  and removable first tube  26  make up the first lumen and extends into the bronchia. The first lumen also includes an inflatable cuff  27 .  
         [0038]    Either the outer wall of the first tube  26  or the inner wall of the second tube  20  may be provided with raised structures such as ribs, rod-like structures, bubbled structures, or the like  24  which form a first suction channel  22  between the walls of the two tubes  20  and  26 . The distal end  42  of the second tube  20  is preferably shaped (e.g. by heating) so that the end  32  curves inwards to reduce tracheal damage and to direct secretions into the first suction channel  22 . The second lumen  25  is a third suction channel that extends along the inside of the endotracheal tube apparatus  50  and opens directly above the second inflatable cuff  27  in the bronchia and below the first inflatable cuff  28  which deflates the lung by suction through a distal insert.  
         [0039]    It should be understood that the examples and embodiments described herein are for illustrative purposes only and that various modifications or changes in light thereof will be suggested to persons skilled in the art and are to be included within the spirit and purview of this application and the scope of the appended claims.