Patent Application
20130158471
The advent of nasoenteric feeding tubes has improved the ability of care givers to provide nutritional support, fluids, medicines, and other therapeutic agents to patients who are debilitated, comatose or otherwise in a condition requiring placement of such feeding tubes. These tubes are typically made of soft, pliable polymeric material such as polyurethane and are well tolerated by the patient. The tubes are typically weighted at their distal end with materials such as mercury or tungsten, and can be positioned using a fluoroscopic procedure, within the small intestine or bowel to reduce the risk of vomiting and aspiration. Positioning can also occur passively with confirmation using serial x-ray evaluation. The weighting of the distal end of the tubes helps to facilitate their insertion and positioning. The distal end has one or more apertures or ports to allow the flow of fluids, medicines, nutrients there through. Nasoenteric feeding is preferred over intravenous feeding because it helps to maintain integrity of the intestinal tract, and it generally provides more complete nutrition.
Inadvertent dislodgment of the feeding tube, however, presents a frustrating, and potentially dangerous, situation. Displacement of the feeding tube can occur in a variety of ways such as: a confused patient accidentally or intentionally dislodging it; or accidentally by hospital or other nursing personnel. Unfortunately, such inadvertent dislodgment is a fairly frequent occurrence. And such displacement can lead to aspiration of the nutritional support into the lungs, causing pneumonia, respiratory complications, and, possibly, death.
Given the degree of occurrence, physicians and nurses have tried various methods to prevent patients from dislodging the feeding tube such as taping or applying adhesive bandage to secure the proximal end of the tube to the patient's nose or, alternatively, using wrist restraints to prevent the patient from accessing the area around the patient's nose, or any combination thereof. The taping, however, can lead to other issues such as skin irritation and breakdown, and there remain a significant number of patients who still dislodge the tubes despite the use of these methods to prevent the dislodgment.
Furthermore, during placement, these tubes do not always pass on their own accord into the small bowel. As mentioned above, they can be actively placed under fluoroscopy or passively, if a patient is in an intensive care setting and not moveable, using serial x-rays to determine when the distal end of the feeding tube is properly positioned in the small bowel. With passive placement of conventional single lumen feed tubes, a guide wire or stylet is typically inserted into the tube and the tube and wire are inserted into the stomach. The patient is usually thereafter given a gastrointestinal stimulant such as Reglan®, to increase gastric motility to encourage passage of the feeding tube into the small intestine. To confirm proper placement, serial x-rays are taken until placement in the small intestine is confirmed. If the feeding tube does not pass into the small bowel or if there is some urgency to achieve proper tube placement, the feeding tube is placed by a radiologist. The radiologist uses fluoroscopic guidance to ensure proper placement in the small intestine. The cost of this procedure is not insignificant and must be repeated if or when a feeding tube is displaced.
Moreover, these feeding tubes can become clogged—either with nutritional supplements or medications, particularly pills which are ground prior to passing them through the feed tube. And if attempts at flushing to clear the tube obstruction are unsuccessful, the tube needs to be removed and replaced and its repositioning verified using one or more of the aforementioned strategies involving passive or active placement and utilization of serial x-ray and, possibly, additional fluoroscopic evaluation.
It is an objective of the present invention to overcome the failings of conventional feeding tube devices with their attendant increased heath care costs represented by replacement after such dislodging or the treatment of associated complications such as aspiration and pneumonia and the frustration experienced by care givers with such displacement. The present invention addresses this shortcoming by minimizing instances of dislodgment of such devices.
It is a further advantage of the invention that its design significantly reduces the need to replace the feeding system due to clogging of the tube providing sustenance and medication.
Moreover, the invention should also reduce interventions used by care givers to prevent displacement of such feeding tubes. These practices include taping the tube to the patient's nose or restraining the patient's wrists—neither of which is desirable.
The present invention addresses these aforementioned shortcomings of conventional feeding tubes and is useful in both a nasogastric application, where the feeding tube is inserted nasally and extends down the esophagus through the stomach and into the small intestine, and or in a percutaneous endoscopic gastronomy application where the feeding tube is placed through the abdominal wall directly into the stomach and extending into the small intestine.
The invention presents a coaxial tube or dual cannula design. In the nasogastric enteric feeding application, the outer tube extends from the nose to the small intestine. The proximal portion of the outer cannula is nested in the naris. By such placement, the patient would have much more difficulty grabbing and pulling on the outer cannula, minimizing the risk of dislodging the outer cannula and its distal end's position within the small intestine.
In a preferred embodiment, the inner tube or cannula, is threaded or passed through the outer cannula until its distal end extends beyond the outer cannula. Although it is understood that since the outer tube is placed within the small bowel, that the inner tube need not necessarily extend beyond the outer tube. In this manner, the inner tube, which carries the nutritional support, fluids, therapeutic agents, and the like, could be intentionally or accidentally pulled by the patient without disrupting the position of the outer cannula. With this system of dual inner and outer tubes, whether the inner tube is partially dislodged or needs to be replaced by the nurse due to clogging, for example, it could be replaced or reinserted using the outer cannula as a guide to ensure proper placement. Also, if the inner cannula is accidentally or intentionally dislodged by the patient, the outer tube would prevent aspiration. With this dual cannula system, the need for subsequent radiologic intervention, and its associated costs, is significantly reduced if not eliminated.
Unless otherwise indicated, all numbers expressing quantities of ingredients, properties such as molecular weight, reaction conditions, and so forth used in the specification and claims are to be understood as being modified in all instances by the term “about.” Accordingly, unless indicated to the contrary, the numerical parameters set forth in the specification and attached claims are approximations that may vary depending upon the desired properties sought to be obtained by the present invention
The terms “a,” “an,” “the” and similar referents used in the context of describing the invention (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. Recitation of ranges of values herein is merely intended to serve as a shorthand method of referring individually to each separate value falling within the range. Unless otherwise indicated herein, each individual value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., “such as”) provided herein is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention otherwise claimed. No language in the specification should be construed as indicating any non-claimed element essential to the practice of the invention.
Moreover, and more particularly, terms such as “sheath,” “catheter,” “tube” or “cannula,” for the purposes of describing elements of the invention, are intended to be construed as interchangeable. Terms such as “ports” or “openings” are intended to be similarly construed. In addition, the terms “guidewire” and “stylet” are also intended to be construed as interchangeable. Similarly, the terms “threaded,” “tracked” and “passed” are intended to be construed as interchangeable.
The invention presents a coaxial tube or, expressed another way, a dual cannula design. In an application for nasogastric enteric feeding, the outer tube would extend from the nose to the small intestine. The proximal portion of the outer cannula would be nested in the naris. With such placement, the patient would have greater difficulty grabbing and pulling on the outer cannula, minimizing the risk of dislodging the outer cannula and its distal end's position within the small intestine. In an application for percutaneous endoscopic gastric feeding, the outer sheath would extend from a puncture site on the abdominal wall, through the stomach and into the small intestine.
The inner tube or cannula, which carries the nutritional support, fluids, therapeutic agents, and the like, could be intentionally or accidentally pulled by the patient or caregiver without disrupting the position of the outer cannula. With this system of dual inner and outer tubes, whether the inner tube is partially dislodged or needs to be replaced by the nurse due to clogging, for example, it could be replaced or reinserted using the outer cannula as a guide to ensure proper repositioning. Also, if the inner cannula is accidentally or intentionally dislodged by the patient, the outer tube would prevent aspiration. With this dual cannula system, the need for subsequent radiologic intervention, and its associated costs, is significantly reduced if not eliminated.
Referring with more specificity to the figures,
A second inner catheter 20 is hollow and has a proximal end 22 and a distal end generally indicated at 24. Second inner cannula 20 has an outer diameter that is less than the inner diameter of first outer sheath 10. Second inner cannula 20 is preferably longer than first outer sheath 10. Second inner cannula 20 is preferably soft or pliant and fabricated from a material from a group including polyurethane, polyvinyl chloride, polyethylene, polyethyleneterephalate or other suitable polymeric materials. Second inner cannula 20 can also include indicators on its outside surface that are visible both to the care provider and visible under x-ray or fluoroscopy. Such indicators can be in the form of bands, ink, laser markings or the like. Such markings placed on the distal end of second inner cannula 20 would confirm that distal end 24 extends beyond distal tip 16. Similarly, such markings placed on proximal end 22 of second inner cannula 20 would confirm that distal end 24 extends beyond distal tip 16 and by how far it is extending beyond distal tip 16 and into the small intestine. In this manner, the care giver knows more precisely when an inner cannula is properly repositioned after dislodgement.
Second inner cannula 20 is preferably longer than first outer sheath 10. Since first outer sheath 10 provides a sealed conduit from the nose to the small intestine, however, second inner cannula 20 need not be longer than first outer sheath 10, As long as distal end 24 is within first outer sheath 10 and extends from the patient's nose to hub 30, its length is sufficient.
Turning to
Alternate embodiments of the distal portion 24 of second inner cannula 20 are depicted in
The dual cannula system described above will now be explained with regard to a particular application.
Preferably, first outer sheath 10 is placed such that it extends three inches to nine inches into the small intestine and second inner sheath 20 extends approximately two inches to six inches beyond radiopaque tip 16 to allow full exposure of the openings in its distal end 24 to the small intestine 80. A guidewire or stylet (not shown) may be used with either the outer sheath or inner sheath to provide additional columnar support thereby facilitating placement of one or both sheaths. Flared proximal end 14, of first outer sheath 10, is intended to seat within the patient's naris and maintain position therein. Luer 30 is connected to a feed pump assembly by external tube 40. Alternatively, passage 36 may be used to deliver therapeutic agents directly into the small intestine.
In the embodiment shown and described with reference to
The coaxial sheath system described above will now be explained with regard to a second particular application.
Preferably, second inner sheath 20 extends approximately two inches to six inches beyond radiopaque tip 16 to allow full exposure of the openings in its distal end 24 to the small intestine 80. A guidewire or stylet (not shown) may be used with either the outer sheath or inner sheath to provide additional columnar support thereby facilitating placement of one or both sheaths.
As shown in
Returning to
Groupings of alternative elements or embodiments of the invention disclosed herein are not to be construed as limitations. Each group member may be referred to and claimed individually or in any combination with other members of the group or other elements found herein. It is anticipated that one or more members of a group may be included in, or deleted from, a group for reasons of convenience and/or patentability. When any such inclusion or deletion occurs, the specification is deemed to contain the group as modified thus fulfilling the written description of all Markush groups used in the appended claims.
Certain embodiments of this invention are described herein, including the best mode known to the inventors for carrying out the invention. Of course, variations on these described embodiments will become apparent to those of ordinary skill in the art upon reading the foregoing description. For example, nasoenteric feeding tubes described in the Background of the Invention above could be substituted for the second inner catheter. The inventor expects skilled artisans to employ such variations as appropriate, and the inventors intend for the invention to be practiced otherwise than specifically described herein. Accordingly, this invention includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed by the invention unless otherwise indicated herein or otherwise clearly contradicted by context.
Specific embodiments disclosed herein may be further limited in the claims using consisting of or consisting essentially of language. When used in the claims, whether as filed or added per amendment, the transition term “consisting of” excludes any element, step, or ingredient not specified in the claims. The transition term “consisting essentially of” limits the scope of a claim to the specified materials or steps and those that do not materially affect the basic and novel characteristic(s). Embodiments of the invention so claimed are inherently or expressly described and enabled herein.
In closing, it is to be understood that the embodiments of the invention disclosed herein are illustrative of the principles of the present invention. Other modifications that may be employed are within the scope of the invention. Thus, by way of example, but not of limitation, alternative configurations of the present invention may be utilized in accordance with the teachings herein. Accordingly, the present invention is not limited to that precisely as shown and described.
