Patent Application
20070089748
The present invention relates to a tracheal tube used for mechanical ventilation of a hospital patient, by insertion of the tube into the trachea of the patient. In particular, the present invention relates to a tracheal tube having means for irrigating and/or evacuating contaminated secretions accumulating above the tracheal tube cuff and thereby reducing the risk of such contaminated secretions entering the lungs of the patient.
Endotracheal intubation involves the insertion of a tubular device, known as an endotracheal tube, into the trachea of a patient. The endotracheal tube passes through the trachea and terminates at a position above the carina, anterior to a position between the second and fourth thoracic vertebrate. Gases may then be introduced through the endotracheal tube and into the lungs of the patient.
The primary purposes of endotracheal intubation, are to mechanically ventilate the patient's lungs, when a disease prevents the patient from normal, breathing induced ventilation, or to apply anesthetic gases during surgical intervention. In order to create enough air pressure to accomplish such mechanical ventilation and to prevent escape of gases past the tube, it is necessary to seal the passageway around the endotracheal tube. A seal may be produced by the use of an inflatable cuff formed integrally with and surrounding the endotracheal tube. When the endotracheal tube has been introduced into the patient's trachea, the inflatable cuff will normally be located about 3 to 5 centimeters above the carina and within the tube-like trachea.
The inflatable cuff is then inflated so as to engage the wall of the trachea and thereby seal the trachea and prevent gases being introduced through the tracheal tube from simply backing up around the tube. While treatment of this sort has proved successful for patients having chronic or acute respiratory diseases, there is a constant risk of several complications.
In particular, many patients receiving endotracheal intubation develop pneumonia, resulting from an infection of the lungs, possibly induced by contaminated, pooled secretions entering the trachea and the lungs after bypassing the epiglottis during intubation. The epiglottis normally operates as a valve which selectively closes the entry into the trachea and lungs, to prevent the introduction of secretions and particulate matter. However, when a tracheal tube is in place, the epiglottis is held in an open position, and secretions which would normally be directed away from the trachea and into the digestive system, instead follow the path of the endotracheal tube and pool above the inflatable cuff of the endotracheal tube.
The greatest risk of such infectious secretions reaching the lungs is upon the cessation of mechanical ventilation. In particular, when the need for endotracheal intubation ends, the inflatable cuff of the endotracheal tube is deflated so that the endotracheal tube may be withdrawn from the patient. The infectious secretions which have pooled above the inflatable cuff are then released and are free to flow into the lungs, where bronchitis or pneumonia may rapidly develop. There is also the risk of the infectious secretions reaching the lungs during the intubation, by aspiration of the secretions past the tracheal tube cuff.
To overcome these risks, it is known in the prior art to combine a single lumen suction tube with a tracheal tube. The suction tube is joined to the endotracheal tube in a suitable manner, the end of the suction tube terminating at a position above the inflatable cuff. The suction tube provides means for suction or evacuation of any pooled secretions which accumulate in the trachea above the inflatable cuff. However, such prior art devices have the disadvantage that use of a single lumen for the suction tube often causes direct suction to be exerted on the tracheal mucosa which may then result in damage to the mucosa.
U.S. Pat. No. 4,840,173 to Porter III, describes an endotracheal tube having a single lumen suction tube merged thereto. In particular, this patent describes a device wherein the suction tube is laminated to the outside of the ventilation tube, so that the suction tube terminates at a position just above the inflatable cuff. The suction tube includes multiple openings which may be used to evacuate secretions which pool above the inflatable cuff. In addition, the inflatable cuff includes a section immediately adjacent to the end of the suction tube that is less flexible than the rest of the inflatable cuff, to insure that the flexible material of the inflatable cuff is not sucked up against the suction tube openings. The endotracheal tube described in the Porter III patent has the disadvantages noted above, that the single lumen suction tube may exert suction on the tracheal mucosa and thereby cause damage to the mucosa. Further, the Porter III device is of a relatively complex design, requiring difficult processing, resulting in expensive production.
U.S. Pat. No. 5,143,062, issued to Peckham, discloses an endotracheal tube comprising a double lumen through which air may be circulated, creating an indirect gentle suction through a suction eye communicating with the distal ends of the lumens, and located at a position proximal to the inflation cuff. This design, however, does not provide adequate suction necessary for aspirating secretions and is easily occluded.
In fact, one problem that frequently arises in many of these catheters is that the suction port becomes occluded with secretions, rendering the function unusable. As such, what is needed is a multilumen catheter capable of suctioning secretions which have pooled above the inflatable cuff in a manner sufficient to accomplish the task but not so strong so as to cause damage to the mucosa. The suction function on such a device would be capable of being cleaned of accumulated secretions, preferably while in use. The instant invention addresses these problems by providing a multilumen tracheal tube and suction catheter system with a rinse function.
The present invention improves upon a tracheal tube by incorporating a rinse lumen therein that enables suctioning of fluids, rinsing of secretions accumulated within the suction lumen while maintaining the rinse function and minimizing contact of the rinse liquid with the subglottic space. In one embodiment, the tracheal tube is formed from a flexible cannula having a length, a distal end, and a proximal end. The cannula consists of a plurality of walls extending substantially along the length of the cannula, dividing the cannula into a plurality of separate lumens including a respiratory lumen, a suction lumen, a rinse lumen, and an inflation lumen. An inflatable cuff surrounds the cannula proximal to the distal end. The inflatable cuff is adapted to seal the trachea of a patient. The inflation lumen is in fluid communication with the inflatable cuff. A closeable port extends through a side wall of the cannula proximal to the inflatable cuff. The port is in fluid communication with the suction lumen. The rinse lumen may terminate within the suction lumen proximal to the port or may terminate within a chamber formed within the suction lumen, the chamber being proximate to the port. A closure mechanism for selectively occluding the port and preventing fluid transfer from the suction lumen to the subglottic space is provided. The closure mechanism is actuated by an activator capable of selectively engaging and disengaging the closure mechanism.
In other embodiments, the closure mechanism may be in the form of a plug attached to a slidable member, the slidable member extending axially along the cannula and terminating at a user manipulable end, the user manipulable end comprising the activator.
Other embodiments may provide for a slidable member having a surface that is movable between at least two positions, the slidable member movable in response to liquid impingement upon the surface, the surface comprising the activator.
In still other embodiments, the tracheal tube may have an inflatable cuff having a shape to block a trachea beneath a glottis of the patient. A cannula may be disposed through the inflatable cuff. Such a cannula may contain a respiratory lumen, a suction lumen, and a rinse lumen. The suction lumen may have a port for suctioning a subglottic space external to the cannula while simultaneously enabling ventilation through the respiratory lumen. The rinse lumen may terminate within the suction lumen proximate to the port or may terminate within a chamber formed within the suction lumen, the chamber being proximate to the port.
In another embodiment a method of suctioning fluids from the subglottic space within an intubated patient is described. The method includes inserting a multilumen catheter into a patient's trachea, and inflating a cuff so as to sealingly engage the walls of the trachea to minimize the flow of fluids from the subglottic space into the patients lungs. The patient may be continuously ventilated through at least one lumen of the multilumen catheter. Suctioning of fluids from the subglottic space may be conducted through at least one other lumen. This lumen should have a port extending through a side wall of the catheter proximate to the cuff to access such fluids. This suction lumen may be rinsed by introducing a rinse liquid into the suction lumen proximate to the port through at least another lumen while suctioning fluids from the subglottic space. Rinsing may be accomplished under turbulent flow conditions, including as a spray. A closure mechanism for selectively occluding the port and preventing fluid transfer from the suction lumen to the subglottic space is provided. The method includes the steps of activating the closure mechanism so as to occlude the port, irrigating the suction lumen with the rinse liquid introduced into the suction lumen through the rinse lumen, maintaining suction on the suction lumen so as to evacuate the suction lumen of rinse liquid, all while maintaining ventilation to the patient.
Other objects, advantages and applications of the present invention will be made clear by the following detailed description of a preferred embodiment of the invention and the accompanying drawings wherein reference numerals refer to like or equivalent structures.
Reference will now be made to the drawings in which the various elements of the present invention will be given numeral designations and in which the invention will be discussed so as to enable one skilled in the art to make and use the invention. It is to be understood that the following description is only exemplary of the principles of the present invention, and should not be viewed as narrowing the pending claims. Those skilled in the art will appreciate that aspects of the various embodiments discussed may be interchanged and modified without departing from the scope and spirit of the invention.
Referring to
A port 24 extends from the suction lumen 16 through a wall 25 of the cannula 12 to an exterior surface 27 of the cannula 12. The port 24 in the depicted embodiment is proximate to an upper surface of the cuff 22. As such, the suction lumen 16 is adapted to suction fluids that collect above the cuff 22 in the patient's subglottic area without negatively impacting ventilation of the patient through the respiratory lumen 14. The rinse lumen 18, in this embodiment terminates within the cannula 12, specifically within the suction lumen 16 at an exit 30 as depicted in
As shown in
For example, in the
In certain embodiments, the closure mechanism 50 may seat against an interior surface of the suction port 24 as shown in
The rinse liquid 28 itself, may comprise water, saline, as well as some other biocompatible liquid. A medicament, for example, an antiseptic or an antibiotic, or a treatment such as a surfactant may be added to the rinse liquid to obtain a desired effect on the patient, or to ease suctioning and/or cleaning of the suction lumen 16. Since the main purpose of the rinse liquid 28 is to rinse and/or clean the suction lumen 16, introducing the liquid into the suction lumen 16 in a turbulent manner will enable better cleaning of the suction lumen. As such the exit 30 of the rinse lumen 18 may be configured so as to foster turbulent flow or a spray pattern as depicted in
Looking back once again to the cross sectional view of
Other arrangements are included in the spirit and scope of the invention. For example, the layout of the lumens within the cannula 12 may be altered, moreover, the rinse lumen 18 may be formed in another wall, such as wall 25 of the cannula or it may be a self contained lumen not embedded within any one of the walls of the cannula 12.
In use, the caregiver would insert the multilumen catheter or tracheal tube 10 into the patient's trachea 37 in a manner known and understood by those of skill in the art. The inflatable cuff 22 would be inflated through the inflation lumen 34 so as to sealingly engage the walls 39 of the patient's trachea 37. This would effectively prevent or at least minimize flow of undesirable fluids from the subglottic space into the bronchus and lungs. Ventilation of the patient through the respiratory lumen 14 may occur at this time and continue for as long as necessary.
At the discretion of the caregiver, the subglottic space within the patient's trachea may be suctioned through the suction lumen 16 via the port 24 through the wall 25 of the cannula 12. During suction, the suction lumen 16 may be rinsed by introduction of the rinse liquid 28 through the rinse lumen 18. The closure mechanism 50 is activated via the activator 52, which may be a function of the application of the rinse liquid 28 or may be via a user manipulable end 58 as described above. Actuation of the activator 52 occludes the port 28 and enables irrigation of the rinse lumen 18 without liquid 28 entering the subglottic space. Suctioning may continue thereby creating a flow of rinse liquid 28 from the rinse lumen 18 through the suction lumen 16 from where it is ejected and disposed. During this process, ventilation of the patient through the respiratory lumen 14 may of course continue unaffected.
Moreover, the rinse liquid 28 may be injected into the suction lumen 16 in a turbulent manner, including as a spray at or near the port 24 so as to better rinse the entire lumen 16. Rinsing the suction lumen 16 at the same time that suctioning is performed serves at least two functions, the first is that it minimizes the inadvertent flow of the rinse liquid 28 out of the cannula 12 and into the patient's subglottic space, and the second is that it increases the turbulent flow of the rinse liquid 28 at the port 24 and throughout the suction lumen 16 as well. Additionally, since the patient is isolated from the rinse liquid 28, higher pressures and greater suctioning may be used within the tracheal tube 10 without significantly increasing the risk to the patient that he will be subject to such pressures or vacuum.
As an alternative step, a treatment may be added to the rinse liquid 28 such as a medicament, for example, an antiseptic or an antibiotic. In that case, it may be desirable to allow the rinse liquid 28 to exit the cannula 12 and enter the subglottic space so as to gain the desired therapeutic effect prior to suctioning. Once the subglottic space is suctioned, the port 24 may be occluded as described above and rinse liquid 28 applied to the suction lumen 16.
As used herein and in the claims, the term “comprising” is inclusive or open-ended and does not exclude additional unrecited elements, compositional components, or method steps.
While various patents have been incorporated herein by reference, to the extent there is any inconsistency between incorporated material and that of the written specification, the written specification shall control. In addition, while the invention has been described in detail with respect to specific embodiments thereof, it will be apparent to those skilled in the art that various alterations, modifications and other changes may be made to the invention without departing from the spirit and scope of the present invention. It is therefore intended that the claims cover all such modifications, alterations and other changes encompassed by the appended claims.
