When a patient has been administered general anesthesia for a surgical procedure or for emergency airway access in cases requiring ventilatory support, it is common to insert a device, such as an endotracheal tube, through the mouth or nose and into the trachea to establish and maintain a patent airway. In most cases, the endotracheal tube includes an inflatable cuff that surrounds the tube and that is inflated with air or another fluid to seal the tube within the trachea. Such a seal both ensures that air can reach the patient's lungs, for instance when positive pressure ventilation is performed, and that the lungs do not aspirate contents from the patient's stomach, for instance when the patient vomits while an individual is unconscious or only partially awake. Unfortunately, however, inflation of the endotracheal tube cuff can place excessive pressure on the patient's adjacent tissues, such as mucosa of the trachea, which can cause tissue damage.
Over the past two decades additional airway devices such as the laryngeal mask airway (LMA) have become a common airway management device used by the anesthesia and emergency responder community. Such devices do not have a cuff that is inflated within the trachea and further is not inserted into a trachea. Instead, an elliptical mask is provided at the end of a tube and is deployed within the pharynx to form a seal on top of the glottis. As a cuff is not inflated within the trachea, the type of damage to trachea that can be caused by endotracheal tubes is avoided. However, LMAs do not always form an adequate seal over the glottis and, therefore, may not actually secure the airway as would an endotracheal tube. This can, for example, be the case when the mask is not fully inflated or the inflated mask does not fit well the anatomy of the patient. Even if the mask fits well to the patient anatomy and creates a good seal, the pressure applied to the pharynx can cause tissue trauma and its related complications, such as throat pain, nausea and vomiting.
In addition, difficult trachea intubation is frequently encountered during emergency resuscitation outside of the hospital setting. LMA is a recommended alternative in case trachea intubation is difficult or impossible. However, the LMA may not be inserted appropriately by the medical professional and/or a gas jet generated from positive pressure ventilation may cause gas to enter the stomach.
In view of the above discussion, it can be appreciated that it would be desirable to have an alternative means for establishing a patent airway.
The present disclosure may be better understood with reference to the following figures. Matching reference numerals designate corresponding parts throughout the figures, which are not necessarily drawn to scale.
Described herein is a novel and improved pharyngeal tube for establishing an airway within a patient, the pharyngeal tube comprising: an elongated hollow tube including a proximal end and a distal end; a mouthpiece provided at the proximal end; and one or more lateral openings provided at or near the distal end of the hollow tube, the one or more lateral openings being formed in a lateral wall of the hollow tube; wherein a distal tip of the hollow tube is sealed so that air cannot escape the tube from its distal tip. In some aspects, the mouthpiece forms an airtight seal at the patient's mouth. In other aspects the mouthpiece includes an inner flange configured to be positioned between the patient's teeth and lips, and an outer flange configured to be positioned on the outside of the patient's lips. In some aspects, the hollow tube comprises multiple lateral openings. In other aspects the hollow tube comprises a single lateral opening. In some embodiments, the pharyngeal tube further comprises a pressure relief valve configured to vent air from the hollow tube when pressure within the hollow tube exceeds a predetermined pressure threshold. In other embodiments, the hollow tube further includes an inner septum that divides the tube into first and second lumens that are connected at the distal end of the tube. In certain embodiments, the hollow tube further comprises an inner channel that that extends along the inner surface or in the wall of the tube. In some aspects, the inner channel is configured to exist as a suction or injection catheter. In other aspects, the inner channel is configured to exist as a catheter that can be used as a carbon dioxide or other gas sampling line. In some embodiments, the suction catheter is associated with a reservoir in which fluid removed from the hollow tube can be deposited. In some embodiments, the hollow tube has multiple inner channels. A first channel is for inspiratory gas flow and a second channel is for expiratory gas flow in order to reduce dead space of ventilation. In some embodiments, the first lumen is for inspiratory gas flow and the second lumen is for expiratory gas flow. In alternative embodiments the inner channel contains a gastric tube. In still other embodiments a gastric tube is attached and runs parallel to the pharyngeal tube.
The foregoing has outlined various features of the present disclosure in order that the detailed description that follows may be better understood and is not indicative of all possible embodiments of the invention. Additional features and advantages of the disclosure will be described hereinafter.
Referring to the drawings in general, not necessarily shown to scale, it will be understood that the illustrations are for the purpose of describing particular implementations of the disclosure and are not intended to be limiting thereto. While most of the terms used herein will be recognizable to those of ordinary skill in the art, it should be understood that when not explicitly defined, terms should be interpreted as adopting a meaning presently accepted by those of ordinary skill in the art.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only, and are not restrictive of the invention, as claimed. In this application, the use of the singular includes the plural, the word “a” or “an” means “at least one”, and the use of “or” means “and/or”, unless specifically stated otherwise. Furthermore, the use of the term “including”, as well as other forms, such as “includes” and “included”, is not limiting. Also, terms such as “element” or “component” encompass both elements or components comprising one unit and elements or components that comprise more than one unit unless specifically stated otherwise.
As described above, it would be desirable to have means for establishing a secure airway that minimize or avoid common complications, such as failure of establishing a patent airway, patient tissue trauma, or nausea with risk of aspiration associated with conventional devices. Disclosed herein are examples of such device and means. In one embodiment, a pharyngeal tube is used to establish a patent airway without inflating a balloon or other sealing element within the trachea or pharynx but only at the opening of the mouth. As used herein the term secure airway indicates a patent airway with an open pathway between a patient's lungs and the outside world. The pharyngeal tube comprises an elongated hollow tube that is configured for insertion into the pharynx via the mouth. At the proximal end of the tube are flanges that are configured for placement on both the inside and the outside of the patient's lips so as to form a seal at the patient's mouth. Near the distal end of the tube are one or more openings formed in the lateral walls of the tube that enable air to exit the tube in the lateral direction and enter the pharynx and trachea. As there is no opening provided at the distal tip of the tube, the air pressure is sufficient to maintain patency of the pharynx and no air is directed toward the esophagus, thereby minimizing or avoiding gastric insufflation. During expiration, the recoil of lung and chest wall generates a pressure gradient which allows the gas expired from lung to enter the side openings and exhaled through the pharyngeal tube.
In the following application, various specific embodiments are described. It is to be understood that those embodiments are example implementations of the disclosed inventions and that alternative embodiments are possible. Such alternative embodiments include hybrid embodiments that include features from different disclosed embodiments. All such embodiments are intended to fall within the scope of this disclosure.
As is apparent in
Provided at or near the distal end 16 of the tube 12 are one or more side openings 24 of sufficient size and shape to allow pressurized air to be delivered through the tube to the patient or ejected in reverse direction from the tube during expiration. Further, the tube 12 or openings 24 may also maintain patency of the pharynx and trachea enabling adequate ventilatory support. Because this design also allows positive end expiratory pressure (PEEP), for instance at 5-10 cm H2O, the pharynx is kept patent. If the patient is kept on spontaneous breathing, the negative pressure generated during inspiration and positive pressure generated by the recoiling of chest wall and lung create the pressure gradient through the side openings and allow air in during the inspiratory phase and out during the expiratory phase. If the patient is kept on mechanical ventilation, the inward gas flow is generated by the pressure gradient in the inspiratory phase and the reverse flow is generated by the recoiling of chest wall and lung as it occurs in the spontaneous breathing. The airtight seal of the device occurs at the mouth, therefore positioning of the device does not require a seal at the glottis. In the illustrated embodiment, these openings 24 may take the form of small circular shaped openings that are formed in the lateral wall of the tube 12, but it shall be understood by one of ordinary skill that any other shaped opening(s) may be utilized in other embodiments. Accordingly, the openings 24 may be referred to as lateral openings. Notably, while multiple openings 24 are shown in
Although one or more lateral openings 24 are provided near the distal end 16 of the tube 12, it is noted that the distal tip 26 of the tube is sealed (i.e., comprises no openings) so that air can only escape from the tube in lateral directions.
With further reference to
To use the pharyngeal tube 12, it is passed through the patient's mouth, soft palate, tongue, and epiglottis until the distal end 16 is positioned in the pharynx adjacent to the trachea. In some embodiments, the distal end 16 may reach the proximal portion of esophagus or possibly enter trachea through glottis. The patient's lips are positioned between the inner and outer flanges 20, 22 so as to form a seal. For example, the inner flange 20 is positioned between the patient's lips and teeth or gums, and an outer flange 22 is positioned against the outside of the patient's lips. Next, the ventilator tube can be connected to the connector 28 located at the proximal tip of the tube 12. When this positioning is performed, the tube 12 will be positioned in similar manner to that shown in
As discussed previously, the pharyngeal tube need not include multiple openings. For example, the tube can instead comprise a single, relatively large opening.
It shall be understood that the exemplary embodiments discussed above may incorporate other features from further embodiments discussed herein or vice versa. For example, the pressure relief valve 48 may be included in the initial embodiment of
Embodiments described herein are included to demonstrate particular aspects of the present disclosure. It should be appreciated by those of skill in the art that the embodiments described herein merely represent exemplary embodiments of the disclosure. Those of ordinary skill in the art should, in light of the present disclosure, appreciate that many changes can be made in the specific embodiments described, including various combinations of the different elements, components, steps, features, or the like of the embodiments described, and still obtain a like or similar result without departing from the spirit and scope of the present disclosure. From the foregoing description, one of ordinary skill in the art can easily ascertain the essential characteristics of this disclosure, and without departing from the spirit and scope thereof, can make various changes and modifications to adapt the disclosure to various usages and conditions. The embodiments described hereinabove are meant to be illustrative only and should not be taken as limiting of the scope of the disclosure.
Number | Date | Country | Kind |
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202010249473.0 | Apr 2020 | CN | national |
This application claims the benefit of U.S. Provisional Patent Application No. 62/895,295 filed on Sep. 3, 2019 and CN Application No. 202010249473.0 filed on Apr. 1, 2020, which are incorporated herein by reference.
Filing Document | Filing Date | Country | Kind |
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PCT/US2020/049154 | 9/3/2020 | WO |
Number | Date | Country | |
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62895295 | Sep 2019 | US |