FIELD

The present application relates generally to airway devices and more specifically to airway devices with notched areas in their topside and underside for engagement with a patient's anterior teeth to hold the patient's mandible in a forward thrusted position that encourages an unobstructed airway; and to designs and uses for such airway devices, which are particularly useful during bag-mask ventilation, endotracheal tube placement, and endoscopy.

BACKGROUND

The present application relates primarily to three health-care areas: namely obtaining and maintaining an unobstructed airway during ventilation of an unconscious patient with a bag-mask resuscitator, placing an endotracheal tube in a conscious patient, and performing lung or upper gastrointestinal endoscopy. The application also relates to the issue of gagging when these procedures are performed on conscious patients.

Forces and movements described herein make use of anatomical terms typically associated with an erect posture; thus, although most patients requiring the described treatments are supine, “upward” will mean away from the feet and toward the top of the head (i.e. superiorly of the patient) rather than toward the ceiling, and forward will mean forward relative to the face (i.e. anteriorly of the patient).

A conscious person automatically keeps an unobstructed airway without conscious effort by adjusting the tone of the small muscles of the pharynx (the airway from mouth to larynx) and the larynx (the structure that acts as the portal to the trachea). This tone is lost in comatose or anesthetized patients. Then the airway may be obstructed by the tongue and other soft tissues, making bag-mask ventilation difficult or impossible. This obstruction can sometimes be overcome by introducing an oral airway into the mouth and/or by jaw thrust; pushing the jaw forward relative to the face. However, bag-mask ventilation even with these measures often provides inadequate ventilation except in the hands of very experienced practitioners such as anesthesiologists. This is because of the complex hand maneuver required to pull the jaw forward to open the airway (the jaw thrust) while simultaneously pushing the mask firmly backwards (i.e. posteriorly) onto the face to achieve a good seal. This skilled maneuver takes considerable time to teach, learn, and maintain. Many health care workers (nurses, family practitioners, and others) are called upon infrequently to resuscitate patients who are not breathing, meaning that they are not skillful at maintaining proper jaw thrust during bag-mask ventilation due to infrequent use and practice of this skill.

The temporomandibular jaw joint is a complex joint. It has a hinge function providing pivotal motion when the jaw opens, closes, and bites hard. It is simple for a practitioner to learn to close the jaw firmly through hinged motion by pressing the mandible toward the maxilla. As well as being a simple hinge, the jaw can subluxate (partially dislocate) to enable the mandible to angulate from side to side relative to the maxilla and thus perform the complex chewing maneuvers necessary for an omnivore. By subluxing both temporomandibular joints at once, one can also advance the mandible forward relative to the maxilla and rest of the face (jaw thrust). Most people can bite their upper lip with their lower teeth—effectively a jaw thrust. This tends to reduce soft tissue obstruction and opens the airway to allow good ventilation.

In a supine patient, gravity acts to allow the tongue, and other soft tissues from the front of the airway to fall back and lie against the back of the airway, causing obstruction. Jaw thrusting usually overcomes these obstructions. An experienced practitioner typically holds the jaw forward with the fifth finger behind the mandible to apply jaw thrust while pressing firmly backwardly on the mask with his/her thumb and index finger and while also pressing upwardly on the mandible with the middle and ring fingers. This procedure is more difficult than it looks. By comparison, an inexperienced practitioner will typically place all fingers below the mandible, where he/she can apply only hinge pressure. Hinge pressure is easy to apply for the novice or for the practitioner who is rarely called upon to mask ventilate (most physicians and nurses), but cannot be relied upon to provide good ventilation for most unconscious patients, especially those who are edentulous or obese. In these scenarios, a Guedel-type airway will often be used to hold the tongue forward and allow ventilation, but even such devices cannot be relied on exclusively to do so without jaw thrust.

In summary, it is relatively easy to hold a mask on firmly while pulling the jaw into a closed position by applying hinge force, but it can be difficult to provide effective jaw thrust while performing bag-mask ventilation.

Making it easier to thrust the jaw forward and hold it there while bag-mask ventilating could be helpful for the occasional or unskilled user. Beginners (and occasional users) typically just push the mask downward on the face, thereby increasing the obstruction to ventilation. Experts grasp the mandible, open the mouth (through pivotal hinge action), thrust the jaw to protract the mandible, and then apply the mask without releasing the jaw thrust. More specifically, the expert typically places their fifth finger behind the angle of the jaw to pull forward; with their fourth finger pulling forward on the soft tissues, their middle finger pushing the mandible upwardly, and their thumb and index fingers pushing the mask backward into firm compliance with the face. All of these finger positions are subtly adjusted for different bite and soft tissue configurations, and so the procedure requires significant skill and dexterity.

It may be desirable to provide a solution enabling confident un-obstruction of the airway during use of a bag-mask resuscitator by trainees and non-specialized practitioners of lesser skill and/or experience level than anesthesiologists or other experienced/specialized practitioners who have worked to develop the forgoing technique.

Regarding elective diagnostic flexible bronchoscopy and gastroscopy, a bite block may be used to protect the very delicate scopes from damage from inadvertent biting by the patient. Such procedures are performed thousands of times per day in Canada and the USA, and typically use such bite blocks to protect the scope, but conventional bite blocks do not optimally position the jaw for scoping.

Turning to placement of an endotracheal tube in a conscious patient, it is desirable to provide an oral airway that: (a) protects the bronchoscope from damage by biting while also opening the airway, (b) causes minimal stimulation of gag, choke, or cough reflexes, and (c) directs the bronchoscope toward the trachea.

Commonly, the trachea is intubated by looking down into the mouth and throat of an anesthetized or comatose patient with a lighted device called a direct laryngoscope. A variety of congenital and acquired deformities of the face, mouth, or throat can make intubation of the trachea with this method difficult or impossible. For airway situations where intubation is known or suspected to be difficult, a technique is used that employs topical anesthesia of the mouth and throat followed by entering the trachea with a flexible bronchoscope while the patient is awake (“awake fibre-optic intubation”). The bronchoscope is armed with an endotracheal tube to slide over it into the trachea when the bronchoscope is in the trachea. Meanwhile, the awake patient can assure his own ventilation by breathing around the bronchoscope. Biting on the bronchoscope can cause breakage of the glass fibers inside making it impossible to see the trachea and requiring expensive repairs.

Special airway devices have been developed to direct the bronchoscope toward the trachea and prevent it from being bitten by the patient, including the Williams Airway Intubator (Williams Airway Intubator Ltd, Calgary, Canada), the Ovassapian Fiber Optic Airway (Medline Industries, Inc. One Medline Place Mundelein, Ill. 60060), and the Berman Intubating Airway (Vital Signs, Totowa, N.J., USA). It is easily appreciated that all of these are essentially modified Guedel airways.

An important problem is commonly encountered in attempting awake fibre-optic intubation. Humans are very sensitive to hard foreign bodies touching the tissues of the pharynx (back of the mouth—gagging and retching); within the larynx (voice box—spasm and choking); and within the trachea (violent coughing). Topical local anesthetic or nerve blocks are commonly used to anesthetize the airway to enable awake intubation. The most sensitive and most difficult reflex to adequately anesthetize and supress in many patients is the gag reflex, which is activated by pressure on the back wall of the airway behind the tongue. All of the aforementioned airway devices, except the simple bite block, can cause gagging when inserted.

Other airway devices and bite blocks useful in placement of an endotracheal tube with a bronchoscope include those shown in U.S. Pat. Nos. 4,425,911, 5,590,643 and 8,146,601 and U.S. Patent Application Publication Number 2012/199140.

Of these references, U.S. Pat. No. 5,590,643 discloses an airway device with top and bottom notches therein respectively engageable by anterior maxillary and mandibular teeth and positioned relative to one another so that placement of the mandibular teeth in one of the bottom notches achieves a thrusted or protracted position of the mandible, which encourages opening of the patient's airway into an unobstructed state. The airway described in U.S. Pat. No. 5,590,643 includes a central longitudinal bore through which an endoscope can be passed, followed by an endotracheal tube fed along the endoscope. A potential drawback of this design is that while the through-bore enables such feeding of the bronchoscope and endotracheal tube through it, the larger endotracheal tube connector at the proximal end of the endotracheal tube cannot fit through this central bore of the airway, and so once the endotracheal tube has been successfully placed, removal of the airway requires that the endotracheal tube connector be removed from the endotracheal tube to allow the airway to be slid off of the endotracheal tube. Endotracheal tube connectors are normally fitted on the endotracheal tube by a tapered force-fit, and there is potential danger that pulling the connector in an attempt to remove it from the endotracheal tube will withdraw the endotracheal tube from the patient's trachea.

In view of the forgoing, there is room for improvement in the design and use of airway devices.

SUMMARY

An embodiment of the disclosure is an airway device comprising:

a body comprising:

a topside and an opposing underside separated in a height direction of said body;

a proximal end and opposing distal end separated in a longitudinal direction of said body;

an upper notch defined in the topside of the body and extending in a lateral direction transverse to the longitudinal and height directions for receipt of anterior maxillary teeth of a patient in said upper notch;

a lower notch defined in the underside of the body and extending in the lateral direction for receipt of anterior mandibular teeth of the patient in said lower notch, said lower notch being positioned relative to the upper notch in the longitudinal direction of the airway so as to position the patient's mandible in a protracted position to encourage an unobstructed state of the patient's airway; and

a longitudinal channel recessed into the underside of the body and spanning longitudinally from the proximal end of the body toward the opposing distal end thereof, the longitudinal channel having a cross-sectional area of sufficient size to accommodate an outer diameter of an endoscope therein to enable introduction of said endoscope orally into the patient while the body is held in a working position engaged between the maxillary and mandibular teeth of the patient at the upper and lower notches of the body.

The endoscope may be a bronchoscope or a gastroscope.

Another embodiment of the disclosure is an airway device comprising:

a body comprising:

a topside and an opposing underside separated in a height direction of said body;

a proximal end and opposing distal end separated in a longitudinal direction of said body;

an upper notch defined in the topside of the body and extending in a lateral direction transverse to the longitudinal and height directions for receipt of anterior maxillary teeth of a patient in said upper notch;

a lower notch defined in the underside of the body and extending in the lateral direction for receipt of anterior mandibular teeth of the patient in said lower notch, said lower notch being positioned relative to the upper notch in a longitudinal direction of the airway so as to position the patient's mandible in a protracted position to encourage an unobstructed open state of the patient's airway; and

a longitudinal channel recessed into either the underside or the topside of the body and spanning longitudinally from the proximal end of the body toward the opposing distal end thereof, the longitudinal channel having a cross-sectional area of sufficient size to accommodate an outer diameter of an endoscope therein to enable introduction of said endoscope orally into the patient while the body is held in a working position engaged between the maxillary and mandibular teeth of the patient at said upper and lower notches of the body;

wherein the longitudinal channel terminates in a curved downturned wall imparting directional guidance of the endoscope downwardly from the longitudinal channel.

Yet another embodiment of the disclosure is an airway device and a bag-mask resuscitator in combination, said airway device comprising a transversely oriented upper notch defined in a topside of the airway for receipt of anterior maxillary teeth of the patient within said upper notch in a working position of the airway device, and at least one transversely oriented lower notch defined in an underside of the airway for receipt of anterior mandibular teeth of the patient within said lower notch in the working position of the airway device, said lower notch being positioned relative to the upper notch in a longitudinal direction of the airway so as to position the patient's mandible in a protracted position to encourage an unobstructed state of the patient's airway in the working position of the airway device, the airway device being arranged such that single-handed urging of the patient's mandible in a hinged manner toward the patient's maxilla by a same hand that is simultaneously used to urge a mask of the bag-mask resuscitator against a facial area of the patient maintains the working position of the airway device between the maxillary and mandibular teeth of the patient so as to thereby maintain the protracted position of the patient's mandible.

A further embodiment of the disclosure is a method of preparing a patient for ventilation by a bag-mask resuscitator, the method comprising:

providing an airway device comprising a transversely oriented upper notch defined in a topside of the airway for receipt of anterior maxillary teeth of the patient within said upper notch, and a transversely oriented lower notch defined in an underside of the airway for receipt of anterior mandibular teeth of the patient within said lower notch, said lower notch being positioned relative to the upper notch in a longitudinal direction of the airway so as to position the patient's mandible in a protracted position to encourage an unobstructed state of the patient's airway;

placing the airway device in a working position in which maxillary teeth of the patient engage said upper notch in the topside of the airway device and mandibular teeth of the patient engage in said lower notch in the underside of the airway device, thereby achieving the protracted position of the patient's mandible and encouraging the unobstructed state in the patient's airway;

simultaneously and one handedly urging hinged closure of the mandible toward the maxilla to maintain the working position of the airway between maxillary and mandibular teeth while urging a mask of the bag-mask resuscitator against a facial area of the patient.

Another embodiment of the disclosure is the use of a bag-mask resuscitator and an airway device in combination, said airway device comprising a transversely oriented upper notch defined in a topside of the airway for receipt of anterior maxillary teeth of the patient within said upper notch in a working position of the airway device, and at least one transversely oriented lower notch defined in an underside of the airway for receipt of anterior mandibular teeth of the patient within said lower notch in the working position of the airway device, said lower notch being positioned relative to the upper notch in a longitudinal direction of the airway so as to position the patient's mandible in a protracted position to encourage an unobstructed state of the patient's airway in the working position of the airway device, the airway device being arranged such that single-handed urging of the patient's mandible in a hinged manner toward the patient's maxilla by a same hand that is simultaneously used to urge a mask of the bag-mask resuscitator against a facial area of the patient maintains the working position of the airway device between the maxillary and mandibular teeth of the patient so as to thereby maintain the protracted position of the patient's mandible.

Another embodiment of the disclosure is a method comprising:

providing an airway device having a topside and an opposing underside separated in a height direction of said body, a proximal end and opposing distal end separated in a longitudinal direction of said body, an upper notch defined in the topside of the body and extending in a lateral direction transverse to the longitudinal and height directions for receipt of anterior maxillary teeth of a patient in said upper notch, a lower notch defined in the underside of the body and extending in the lateral direction for receipt of anterior mandibular teeth of the patient in said lower notch, and a longitudinal channel recessed into either the underside or the topside of the body and spanning longitudinally from the proximal end of the body toward the opposing distal end thereof;

with the airway device received between the anterior maxillary and mandibular teeth of the patient with the mandible of the patient in a protracted position maintained by engagement of the anterior maxillary and mandibular teeth in the upper and lower notches respectively, passing a distal end of an endoscope through the longitudinal channel to a target destination in the patient; and

while maintaining the distal end of the endoscope at the target destination, withdrawing the longitudinal channel of the airway device from an embraced position about the endoscope by freeing the endoscope from the longitudinal channel through an open top or bottom thereof at the topside or underside of the airway device.

In one embodiment, the endoscope is a bronchoscope, the target destination is the patient's trachea, and freeing of the bronchoscope from the airway device enables feeding of an endotracheal tube along said bronchoscope into the patient's trachea independently of the airway device.

Yet another embodiment of the disclosure is a method of using an airway device and an endoscope in combination, said method comprising with the airway device in a previously achieved position received between the anterior maxillary and mandibular teeth of the patient that are respectively engaged in upper and lower notches at a topside and underside of said airway device with the mandible of the patient in a protracted position maintained by engagement said anterior maxillary and mandibular teeth in said upper and lower notches, and with an endoscope in another previously achieved position reaching through the longitudinal channel to a target destination in the patient, withdrawing the longitudinal channel of the airway device from an embraced position about the endoscope by freeing the endoscope from the longitudinal channel through an open top or bottom thereof at the topside or underside of the airway device.

Another embodiment of the disclosure is the use of an airway device and endoscope in combination, wherein:

said airway device comprises a topside and an opposing underside separated in a height direction of said airway device, a proximal end and opposing distal end separated in a longitudinal direction of said airway device, an upper notch defined in the topside of the airway device and extending in a lateral direction transverse to the longitudinal and height directions for receipt of anterior maxillary teeth of a patient in said upper notch, a lower notch defined in the underside of the body and extending in the lateral direction for receipt of anterior mandibular teeth of the patient in said lower notch, and a longitudinal channel recessed into either the underside or the topside of the airway device and spanning longitudinally from the proximal end of the airway device toward the opposing distal end thereof;

said longitudinal channel being arranged to:

accommodate passage of a distal end of the endoscope through the longitudinal channel to a target destination in the patient with the airway device received between the anterior maxillary and mandibular teeth the patient with the mandible of the patient in a protracted position maintained by engagement of the anterior maxillary and mandibular teeth in the upper and lower notches respectively; and

enable withdrawal of the longitudinal channel of the airway device from an embraced position about the endoscope by separation of the endoscope from said longitudinal channel via an open top or bottom thereof at the topside or underside of the airway device so as to free the endoscope from the airway device.

In an embodiment, withdrawing the longitudinal channel of the airway device from the embraced position comprises using a rolling motion of the airway device about a longitudinal axis to withdraw the longitudinal channel from about the endoscope.

In another embodiment, withdrawing the longitudinal channel of the airway device from the embraced position comprises moving the airway device into a lateral position received between posterior maxillary and mandibular teeth on one side of the patient's dental arch, where the device serves as a bite block to protect the endoscope from biting.

