Patent Publication Number: US-2016220773-A1

Title: Laryngeal mask airway

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims the priority benefits of Taiwan application serial no. 104201800, filed on Feb. 4, 2015. The entirety of the above-mentioned patent application is hereby incorporated by reference herein and made a part of this specification. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention relates to a laryngeal mask airway (LMA), and particularly relates to an LMA in a novel structure that allows to further perform an endotracheal intubation procedure. 
     2. Description of Related Art 
     Regardless of basic emergency resuscitation or advanced cardiopulmonary resuscitation, the patency of the respiratory tract and the ventilation of the lung are crucial factors. Even though maintaining the patency of the respiratory tract and the ventilation of the lung are very difficult techniques, such techniques have the most significant impact in emergency services and are of most help to the patient once successfully carried out. In addition to endotracheal intubation, the conventional emergent respiratory tract treatment and lung ventilation procedures in emergency care include the following: i. a mouth-to-mouth or mouth-to-mask artificial respiration procedure; ii. a positive pressure ventilation procedure using a mask having an air storage bag, with assistance of an artificial oropharyngeal or nasopharyngeal respiratory tract; iii. an automatic resuscitation/ventilation procedure with a mask (with the angle of the head and the neck maintained), with assistance of an artificial oropharyngeal or nasopharyngeal respiratory tract. However, the aforementioned procedures are under different limitations to some extent. For example, i. the air may leak from between the mask and the face; ii. the air may be undesirably pumped into the stomach; iii. the respiratory tract cannot be properly protected when the substance is inhaled or aspirated into the respiratory tract or the substance in the stomach flows back; iv. when the patient suffers from a facial damage, the respiratory tract cannot be protected. 
     Of course, most of the limitations above may be eliminated by performing the endotracheal intubation procedure in emergency care. However, for the emergency care personnel, a timely endotracheal intubation procedure may not be necessarily carried out successfully considering the environmental limitation or the patient&#39;s condition. Besides, in practice, it is not possible to provide the most complete and detailed endotracheal intubation training to every emergency care personnel. Some countries, such as the United States, even strictly stipulate that an invasive endotracheal intubation procedure shall only be performed by a licensed medical staff. Thus, in addition to the performing the endotracheal intubation procedure in the emergency care, an emergency procedure and device for respiratory tract treatment and lung ventilation that can be performed easily without the aforementioned limitations are certainly needed. 
     Accordingly, a laryngeal mask airway as shown in  FIG. 1  has been developed. The laryngeal mask airway includes a handle  10 . One end of the handle  10  is sheathed in and connected to a mask body  11 , and a mask bag  12  is disposed on a peripheral edge of the mask body  11 . The mask bag  12  is connected to an inflation tube  13 . The laryngeal mask airway may be used according to the following steps. First of all, a laryngeal mask airway with an appropriate size is chosen, and the air in the mask bag  12  is completely released. Then, the laryngeal mask airway is placed into the patient&#39;s mouth, with the top portion of the laryngeal mask airway facing an inner surface of the patient&#39;s upper teeth, the neck remaining flexible, and the head extending. Then, the mask bag  12  is gently pressed to be disposed at the back of the wall of the pharynx with the index finger, and then the mask bag  12  is guided to a correct position. Afterwards, the handle  10  is gently pressed downward to confirm that the mask bag  12  is fully inserted. Finally, the mask bag  12  is inflated by using the inflation tube  13 , so as to form an enclosed ring pad surrounding the opening of the patient&#39;s glottis. In this way, oxygen or anesthetizing gas may be supplied to the patient&#39;s lung by using the handle  10 . 
     Even though the conventional laryngeal mask airway helps improve the respiratory tract treatment and lung ventilation in the emergency care, further improvement is still needed and there are still issues to work on. After an emergency treatment procedure using the laryngeal mask airway is performed to the patient and the patient is diagnosed by the doctor to further require an endotracheal intubation procedure, since there is no working area at the side of the conventional laryngeal mask airway, and there is no structure for inserting an endotracheal tube designed in advance, the conventional laryngeal mask airway must be removed after the endotracheal tube is inserted to a predetermined position by using the handle  10  of the conventional laryngeal mask airway. When removing the conventional laryngeal mask airway, a stringer needs to be pressed to the endotracheal tube, so as to prevent the endotracheal tube that is inserted and positioned to a predetermined position from being carried along and moved upward during the procedure of removing the conventional laryngeal mask airway. Also, when the stringer is being pressed to the endotracheal tube, the endotracheal tube that is inserted and positioned to a predetermined position may be further pushed downward due to an excessive force exerted during the procedure of removing the conventional laryngeal mask airway. Both circumstances mentioned above may result in an undesired movement of the endotracheal tube. If the endotracheal tube is too deep, the trachea may be damaged, making only one side of the lobes of the lung receive oxygen supply while the other side of the lobes necrotic. If the endotracheal tube is not deep enough, the air supply may be insufficient. Not only the patient may be hurt, the damage may even be unrecoverable or the patient&#39;s life may be in danger. The risk of medical disputes also increases. 
     Furthermore, when performing the endotracheal intubation procedure, an endoscope is usually used together to avoid damages to the vocal cords, so that the endotracheal tube may be inserted to a suitable position under the condition that the vocal cords remain visible. Even though the conventional laryngeal mask airway may be used together with the endoscope, the laryngeal mask airway needs to be withdrawn by having the stringer pressed to the endotracheal tube when the conventional laryngeal mask airway is used. Thus, the stringer can only be pressed to the endotracheal tube after the endoscope placed in the endotracheal tube is withdrawn. Under such circumstance, the medical staff has to perform the intubation procedure under the condition that the vocal cords are not visible, which may easily lead to medical malpractice. 
     Thus, in view of the limitations of the conventional art, how to develop a novel structure with the ideal utility is certainly an issue for the researchers in relevant fields to work on. 
     Based on above, with years of experience in developing, designing, and manufacturing relevant products, the inventors come up with the invention with the ideal utility after careful design and evaluation. 
     SUMMARY OF THE INVENTION 
     The invention provides a laryngeal mask airway, and aims at offering a novel emergency device for respiratory tract treatment and lung ventilation. 
     The present invention provides a laryngeal mask airway with a handle. There is a trench on the handle, wherein one end of the trench is located between the laryngeal mask airway and the handle, and a guiding hole is disposed at this side. The other end of the trench is located at the end of the handle having a C-shaped cross section. The endotracheal tube is conjugated to the laryngeal mask airway with two point fixations: the tip of the endotracheal tube is fixed at the guiding hole; the body of the endotracheal tube is fixed at the C-shaped end of the trench. The aforementioned fixations are temporary and easily dispatched. The laryngeal mask airway of the present invention can be used for a supraglottic airway device as a conventional LMA. If necessary, the endotracheal tube can be intubated through the guiding hole into the trachea. Then, the laryngeal mask airway and the handle can be easily removed after splitting with the endotracheal tube. 
     The laryngeal mask airway according to an embodiment of the invention includes a handle, and a front end of the handle is connected to a mask body. The handle and the mask body are both formed of a flexible polymer material (e.g., polyvinyl chloride (PVC)) for medical use. A guiding hole is formed at a side where the mask body and the handle are connected, and a working area is formed at an external opening of the guiding hole. A check valve with a dome shaped structure is designed in the guiding hole, which prevents air leak during ventilation while the intubation is not interfered. 
     The laryngeal mask airway according to an embodiment of the invention is mainly characterized as in the following. When an endotracheal intubation procedure is completed by using the guiding hole and the laryngeal mask airway is to be removed, a medical staff may hold the endotracheal tube with fingers by using the working area, and hold the handle with the other hand to slowly remove the laryngeal mask airway. When the mask body leaves the patient&#39;s larynx and touches the fingers holding the endotracheal tube, removing of the laryngeal mask airway is paused, and as the mask body is already in a distance from the patient&#39;s larynx, a position where the endotracheal tube is held is moved to a position between the mask body and the patient&#39;s larynx. Removing of the laryngeal mask airway may resume after the endotracheal tube is held again. By operating with the working area, an improper movement of the endotracheal tube caused when removing the laryngeal mask airway is prevented. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention. 
         FIG. 1  is a schematic perspective view illustrating a conventional laryngeal mask airway. 
         FIG. 2  is a schematic perspective view according to an embodiment of the invention. 
         FIG. 3  is a schematic top view according to an embodiment of the invention. 
         FIG. 4  is a schematic partial cross-sectional view according to an embodiment of the invention. 
         FIG. 5  is a schematic reference view illustrating a state of use when an embodiment of the invention is used in emergency care. 
         FIG. 6  is a schematic reference view illustrating a state of use when an embodiment of the invention is used in an endotracheal intubation procedure. 
     
    
    
     DESCRIPTION OF THE EMBODIMENTS 
     Reference will now be made in detail to the present preferred embodiments of the invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers are used in the drawings and the description to refer to the same or like parts. 
     Referring to  FIGS. 2, 3, and 4 ,  FIGS. 2, 3, and 4  illustrate a larynx mask airway according to an embodiment of the invention. However, the embodiment is merely described herein for an illustrative purpose, and the invention is not limited thereto. The laryngeal mask airway includes a handle  20 . A front end of the handle  20  is connected to a mask body  30 . In this embodiment, the handle  20  and the mask body  30  are both formed of a flexible polymer material (e.g., polyvinyl chloride (PVC)) for medical use, and the handle  20  and the mask body  30  are integrally formed. A mask bag  31  is disposed around the periphery of the mask body  30 . Besides, the bag  31  is connected to an inflation tube  32 . A guiding hole  33  is disposed a side where the mask body  30  and the handle  20  are connected, and a guiding trench  21  in communication with the guiding hole  33  is formed on an exterior wall of the handle  20 . A check valve (not shown) with a dome shaped structure is designed in the guiding hole, which prevents air leak during ventilation while the intubation is not interfered. The guiding trench  21  is a structure having a C-shaped cross-section and extending to a free end of the handle  20 . The above embodiment describes a laryngeal mask airway structure for repetitive use. If the laryngeal mask airway is a disposable structure, the mask bag  31  and the inflation tube  32  may not be connected. In this way, the cost can be reduced without influencing the function. 
     The former part of steps of using the laryngeal mask airway according to the embodiments of the invention is substantially the same as steps of using the conventional laryngeal mask airway, except that a front end of an endotracheal tube  40  is engaged into the guiding hole  33 . A major difference between the steps of using the laryngeal mask airway according to the embodiments of the invention and the steps of using the conventional laryngeal mask airway lies in the endotracheal intubation procedure at the latter part of the steps. Referring  FIGS. 5 and 6 , when the patient using the laryngeal mask airway according to the embodiments of the invention requires an additional endotracheal intubation procedure, the intubation procedure of the endotracheal tube  40  is completed as long as the front end of the endotracheal tube  40  penetrates the mask body  30  and extends to a suitable position in the trachea. After the intubation procedure of the endotracheal tube  40  is completed, the laryngeal mask airway according to the embodiments of the invention needs to be immediately removed from the patient. To prevent the endotracheal tube  40  inserted to a predetermined position from being moved when removing the laryngeal mask airway according to the embodiments of the invention, the medical staff may gently hold the endotracheal tube  40  with his/her fingers of the right hand through the guiding trench  21 , then hold the handle  20  with his/her left hand to slowly remove the laryngeal mask airway according to the embodiments of the invention. When the mask body  30  leaves the patient&#39;s larynx and touches the fingers holding the endotracheal tube  40 , the removing the laryngeal mask airway according to the embodiments of the invention is paused. At this time, since the mask body  30  is already in a distance from the patient&#39;s larynx, the position where the endotracheal tube  40  is held may be moved to a position between the mask body  30  and the patient&#39;s larynx. After holding the endotracheal tube  40  again, the removing of the laryngeal mask airway according to the embodiments of the invention may resume until the laryngeal mask airway according to the embodiments of the invention is completely removed from the patient&#39;s mouth. 
     In view of the foregoing, when the patient using the laryngeal mask airway according to the embodiments of the invention additionally requires the endotracheal intubation procedure, the second intubation procedure is avoided, and the medical staff&#39;s fingers may gently hold the endotracheal tube  40  throughout the whole procedure when the laryngeal mask airway is being removed after the endotracheal intubation procedure is performed, so as to prevent the endotracheal tube  40  already inserted to a predetermined position from being moved during the process of pulling the laryngeal mask airway upward to remove the laryngeal mask airway. Even if the laryngeal mask airway  40  already inserted to a predetermined position is moved during the removing of the laryngeal mask airway, the medical staff is able to timely notice the movement and make correction with the fingers holding the endotracheal tube  40 , while with the conventional laryngeal mask airway, the endotracheal tube can only be touched through the stringer, making the hand not sufficiently sensitive. Besides, all the procedures are performed together in a visible condition. Thus, the time required for the emergency care is reduced, and the patient&#39;s discomfort due to repetitive intubation procedures is alleviated. 
     Effect: With the novel structure configuration and technical feature, the laryngeal mask airway of the invention is above to provide an working area for intubation, as compared to the conventional laryngeal mask airway, such that when the laryngeal mask airway is being removed, the endotracheal tube already inserted to a predetermined position may be prevented from being moved. 
     It will be apparent to those skilled in the art that various modifications and variations can be made to the structure of the present invention without departing from the scope or spirit of the invention. In view of the foregoing, it is intended that the present invention cover modifications and variations of this invention provided they fall within the scope of the following claims and their equivalents.