Patent Application
20100313893
The present application is a 35 U.S.C. §371 of PCT/GB2008/003674, which claims priority to Application No. GB0721300.2, filed Oct. 30, 2007. The present application claims priority to these previously filed applications which are incorporated herein by reference.
Not Applicable.
The present invention relates to a laryngeal mask device and more particularly to a laryngeal mask airway device having a tab disposed near the proximal end for facilitating position control of the device and more specifically to such a device in which the tab is adapted to be biasable towards the philtrum of the patient in use.
The laryngeal mask airway device is well known and useful for establishing airways in or administering and monitoring anaesthesia in unconscious patients. The Laryngeal Mask Company Ltd. has marketed one popular laryngeal mask airway device commercially for many years as the “Classic”. Such devices are described for example in U.S. Pat. No. 4,509,514 and generally comprise a mask portion and an airway tube which, when in the fully inserted configuration, establishes an airway in a patient. For convenience of exposition, the term “fully inserted configuration” shall be used herein to refer to a laryngeal mask airway device that has been inserted into a patient and has the following characteristics: (1) the distal end of the mask portion is pressed against the patient's normally closed esophageal sphincter; (2) the cuff forms a seal around the patient's glottic opening; and (3) the airway tube extends from a proximal end located outside the patient's mouth to a distal portion that is coupled to the mask portion, the tube extending through the patient's mouth and the patient's natural upper airway so that the device provides a sealed airway extending from the tube's proximal end to the patient's lungs.
Although such devices have worked well, problems have been encountered during their use. In order for an effective airway to be created in the patient, a seal around the laryngeal inlet must be maintained, requiring that the device should remain stably in place during the medical procedure being performed on the patient. However, this has proven difficult to achieve with a standard LMA device; involuntary movements of the patient during anaesthesia can cause shifting or dislodging of the LMA, reducing its effectiveness.
This can lead to loss of the airway in the patient; a potentially life threatening situation. The medical staff may become distracted from the procedure being carried out on the anaesthetized patient if the airway is lost, because of the need to adjust the device to restore the airway. This is time-consuming, distracting and complicated for medical staff and dangerous for the patient. There is therefore a need for improved LMA devices that remain stably in place during anaesthesia.
It is an object of the present invention to provide a device and method that seeks to mitigate one or more of the above-mentioned disadvantages.
In a first aspect of the invention there is provided a laryngeal mask airway device to facilitate lung ventilation in a patient, comprising an airway tube opening at one end into the interior of a hollow mask portion, the mask portion including a backplate and a cuff, the mask portion shaped to conform to and to fit readily into the actual and potential space behind the larynx and to seal around the circumference of the laryngeal inlet without penetrating into the interior of the larynx, the airway tube extending from a proximal end to a distal end and having a tab disposed near said proximal end, a sealed airway passage extending from the proximal end of the tube to the glottic opening when the cuff is at the inserted location, characterized in that the tab is adapted to be biasable towards the philtrum of the patient in use. This feature allows the user to securely and conveniently fasten the tape to the patient's face or around their head, so that the mask portion is stably urged over the laryngeal inlet.
Preferably, means for biasing the tab towards the philtrum of the patient are integrally formed with the tab. This provides a manufacturing advantage because the manufacture of a single piece is simpler than the manufacture of two pieces, with a subsequent attachment step.
Preferably, the tab is adapted to receive means for biasing the tab towards the philtrum of the patient. Any type of means for biasing the tab towards the philtrum of the patient may then be selected, for example, on the basis of the correct size for a particular patient group.
Preferably, a single location on the tab is adapted for receiving means for biasing the tab towards the philtrum of the patient. This provides a specifically designed position at which the means for biasing the tab can be positioned, either integrally during manufacture or post-production. Preferably, the tab may include a plurality of locations adapted for receiving means for biasing the tab towards the philtrum of the patient. This provides further flexibility in the type of means for biasing the tab towards the philtrum of the patient, for example the means may be conveniently attached to the sides of the tab.
Preferably, the tab is adapted to fixedly receive the means for biasing the tab towards the philtrum of the patient. When the biasing means are fixed on the tab, they are securely fastened, so that there is no risk of the biasing means slipping or moving out of place.
Preferably, the tab is adapted to slidably receive the means for biasing the tab towards the philtrum of the patient. This feature allows the user to slide the biasing means, which would be of particular benefit in ensuring that the position of a buckle or similar fastening is convenient for the user.
Preferably, the tape means is fastened to the face or head of the patient in use. This ensures that if the patient should make any involuntary movements during the medical procedure, the mask will remain more stably in place than if the tape means were attached to an object separate from the patient.
Preferably, the tape means is adjustably attached to the tab. This feature ensures that the LMA device may be securely positioned in a variety of differently sized and shaped patients.
Preferably, the tape means comprises a continuous elasticated length. This feature ensures that the LMA device may be securely and conveniently positioned in a variety of differently sized and shaped patients without requiring adjustments; this would be of particular use where fast establishment of an airway is a priority.
Preferably, the tape means is fastened in use by attaching the ends of at least one length of tape to each other around the face or head of the patient. This feature ensures that the LMA device may be securely positioned in a variety of differently sized and shaped patients.
Preferably, the tape means is fastened in use by attaching the ends of the tape to each other using a hook, buckle, Velcro or knot.
Preferably, the means for biasing the tab towards the philtrum of the patient includes adhesive. This feature may assist in improving the strength of the fastening method, or if used alone, may provide an especially fast method of biasing the tab, which may be useful in emergency situations.
Preferably, the tab extends outwardly in use from the airway tube in a direction extending from the chin of the patient towards the nose of the patient. This position for the tab is advantageous because when it is urged towards the philtrum, the airway seal of the mask portion over the pharyngeal inlet is increased.
Preferably, the tab is biased in use by the incorporated tape means towards the philtrum of the patient in a direction perpendicular to a line extending from the nose of the patient to the chin of the patient. This increases the airway seal of the mask portion over the pharyngeal inlet.
Preferably, the tab extends from the airway tube for at least fifteen millimetres. This length provides an ideal surface for the adaptations required to bias the tab towards the philtrum.
Preferably, the tab is substantially rigid. This ensures that the tab can be used to more securely fasten the LMA device than if the tab were flexible. In the latter case, movement of the tab would cause movements of the tab relative to the patient, reducing the effectiveness of the seal over the glottic opening.
Preferably, the tab includes a first portion and a second portion, the first portion of the tab extending outwardly from the airway tube in a direction extending from the chin of the patient towards the nose of the patient, the second portion extending from the first portion at an angle with respect to the first portion, the angle being different than one hundred-eighty degrees. The angle of less than one hundred-eighty degrees reduces the extent to which the means for biasing the tab towards the philtrum will buckle when used.
Preferably, the airway tube includes a connector portion and a second portion, the connector portion including a proximal portion, a distal portion, and a flange, the flange defining the tab and being disposed between the proximal and distal portions, the distal portion being inserted into a proximal end of the second portion, the proximal portion being cylindrical. The tab therefore protrudes at an appropriate position from the tube so that it is positioned conveniently near to the patient's philtrum. If the tab were positioned further from the philtrum, the means for biasing could be less secure, reducing the effectiveness of the seal over the glottic opening.
Preferably, the tab is slidable mounted on the connector portion of the airway tube. This feature allows adjustment of the position of the tab where necessary, for example if the patient's philtrum is far from the tab once the LMA device is in fully inserted configuration.
Preferably, the tab has an inner diameter in contact with the airway tube or the connector portion, the inner diameter having a top and a bottom portion, the top and bottom portions having a ridged surface.
Preferably, the ridges are adapted to press into the connector portion when the tab is biased towards the philtrum of the patient. This feature ensures that when the tab is used for the purpose of biasing the distal end of the device against the oesophageal sphincter, it is locked into position and will not slide up and down the airway tube or connector portion.
Preferably, the distal end of the device is biased against an esophageal sphincter of the patient in use by the tape means. This stably enhances the seal over the laryngeal inlet.
Preferably, the tab is part of a connector. Optionally, the connector is removable.
In a second aspect of the invention, there is provided a method of providing ventilation to a patient, providing a laryngeal mask airway device as described hereinabove, inserting the cuff through the mouth of the patient to the inserted location; and biasing the tab towards the philtrum of the patient to the patient. This method can be used to ensure that the LMA device does not move around, reducing its effectiveness as an airway, during the medical procedure being performed. The advantage to the medical staff is convenience and confidence in the airway, so that they are free to perform the required procedure.
Preferably, means for biasing the tab towards the philtrum of the patient are attached to or around the head or face of the patient. This ensures that if the patient should make any involuntary movements during the medical procedure, the mask will remain more stably in place than if the tape means were attached to an object separate from the patient.
Preferably, the means for biasing the tab towards the philtrum of the patient include elastic, adhesive, adjustable fastenings, or free ends that may be tied. The type of fastening to be used may selected according to the size and shape of the patient or the specific circumstances, for example the urgency of the requirement for establishment of an artificial airway.
Preferably, the means for biasing the tab towards the philtrum of the patient is adjusted by the user following insertion of the cuff through the mouth to the inserted location. This allows the user to ensure that the tab is maximally biased towards the philtrum.
Preferably, biasing of the tab towards the philtrum of the patient in use causes the distal end of the device to be biased against the esophageal sphincter of the patient. This allows the user to increase the effectiveness of the seal over the laryngeal inlet.
Preferably, the position of the tab on the airway tube is adjusted. This feature is useful to ensure that the tab is positioned at a distance appropriate for biasing towards the philtrum.
An embodiment of the invention will now be described by way of non-limiting example with reference to the accompanying figures, in which:
Referring to
The angle of the tab is also important to avoid buckling or folding of the biasing means in use. For example, as shown in
Another way to describe the orientation of tab 460 with respect to the airway tube is that the tab extends from the wall of the tube, which defines the tube's internal airway passage, outwardly, or away from the internal passage. When the device 400 is in the fully inserted configuration, the tab extends from the tube wall outwardly towards the patient's nose. More generally, if an up-down direction is defined as being along a line extending between the patient's nose and the patient's chin, the tab 460 extends generally in the up-down direction when the device is in the fully inserted configuration.
In addition to facilitating holding device 400 stably in the fully inserted configuration, tab 460 also facilitates insertion of device 400 into a patient and also facilitates general manipulation of the device. The proximal end of the airway tube is typically grasped and manipulated as a laryngeal mask airway device is inserted into a patient. Lubricant is typically applied to facilitate passing the mask portion through the patient's natural airway. However, the lubricant can also make the proximal end of the airway tube slippery and difficult to handle. Tab 460, which extends outwardly from the proximal end of the airway tube, provides an additional surface that may conveniently be grasped during insertion and manipulation of the device. Tab 460 thereby generally facilitates insertion and manipulation of device 400.
As discussed above, device 400 has a single tab 460 that projects generally along the patient's philtrum when the device is in the fully inserted configuration. One reason this configuration is convenient is that the patient's upper lip and cheeks are generally immobile with respect to the rest of the patient's head. In contrast, the patient's lower lip and jaw are easily moved with respect to the head and accordingly provide a less stable platform for anchoring the device 400. However, although a single tab projecting along the upper lip is a convenient configuration, it will be appreciated that other configurations of tabs may be used. For example, devices constructed according to the invention can instead include a tab that projects downward along the lower patient's lower lip, or in some other direction. Alternatively, devices constructed according to the invention can include two tabs, one projecting along the upper lip and another projecting along the lower lip, when the device is in the fully inserted configuration, and the biasing means may be integrally formed or attached to either or both of the tabs and fastened to the patient's cheeks or to other parts of the patient's head.
In use, the mask portion 430 is inserted through the patient's mouth into the patient's pharynx (
Airway tube 410 translates the force from tab 460 to the distal end of the device. The force applied by incorporated tape means 600 acts to generally pull device 400 into the patient and, in particular, to simultaneously bias (a) the tab towards the patient's mouth and (b) the distal end of the device towards a more sealing engagement with the laryngeal inlet. Biasing the distal end of the device in the direction of the arrow D advantageously insures that the distal end 438 of cuff 434 remains generally in firm contact with the patient's normally closed esophageal sphincter. Ensuring that the distal end of device 300 remains in firm contact with the patient's esophageal sphincter advantageously reduces the likelihood of regurgitated material being aspirated into the patient's lungs during anaesthesia. The device can be secured using the biasing means pre-attached to the tab more quickly, conveniently and safely than the prior art devices that are fixed in place using separate means such as tape.
In order to bias the device 400 and increase the sealing engagement with the laryngeal inlet, the tab 460 may be adapted so that it is biased in use towards the philtrum of the patient. For example, the tab 460 may be adapted to receive means for biasing the philtrum of the patient. In other words, the tab may have at least one hole, slit, hook, other attachment means 465 or a combination thereof so that the biasing means 500 may be attached to the tab (
The adaptation of the tab to allow it to be biased in use towards the philtrum, either via means to receive the biasing means or via biasing means integrally formed with the tab has numerous advantages over the prior art. The clinician need not be concerned with the inconvenient coordination of lengths of tape, a position tab, and a patient. He can therefore fix the laryngeal mask airway device in its fully inserted configuration quickly and conveniently. This is a potentially life-saving advantage because the clinician can focus on the unconscious patient instead of on the cumbersome process of fixing lengths of tape to the tab and then to the face of the patient. The adjustable nature of the biasing means ensure that the tab can be used to bias the airway device as required in a patient having a head of any size or shape. A further advantage is that because the biasing means is either attached to a specifically adapted location or integrally formed with the tab, there is no chance of the tape slipping and releasing it from its secure inserted position.
Where the patient's head cannot be rotated, it would be difficult to secure the tape by tying around the back of the head. If the tape were fixedly attached to the tab, this could present a problem in securing the airway device using the tape.
A possible variation on any of the above embodiments is the use, additionally or alternatively, of adhesive tape so that the tape means can be attached directly to the face or head of the patient. By fastening the tape to the face or head of the patient, using adhesive, the need to fasten the tape using buckles, hooks, tying or other means is circumvented. This embodiment of the invention would be most useful in situations where the movement of the head, which would be required in order to fasten the tape around the ears or head of the patient, would be clinically inappropriate. This could also be used to enhance the strength with which the airway device is kept in place during the anaesthetic procedure, when the abovementioned methods of fixing such as tying or adjustable fastenings are used.
Some variation in the shape of patient's faces is observed, in particular how deep-set or prominent the philtrum is. This can create problems when the tab is biased towards the philtrum in order to stably secure the airway device in place. For example, if the tab is not biased sufficiently close to the philtrum, the length of biasing means required to reach the patient's face from the tab may be longer, creating more potential for the device to shift. The tab may therefore be adjustably positioned on the airway tube, so that it can be slid towards or away from the patient's philtrum once the device is in fully inserted configuration. As shown in
| Number | Date | Country | Kind |
|---|---|---|---|
| 0721300.2 | Oct 2007 | GB | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/GB2008/003674 | 10/30/2008 | WO | 00 | 8/19/2010 |
