US3013554A - Airway - Google Patents

Description

Dec. 19, 1961 Filed Aug. 8, 1958 P. SAFAR ETAL AIRWAY 2 Sheets-Sheet 1 WK a ATTORNEY Dec. 19, 1961 P. SAFAR ETAL AIRWAY 2 Sheets-Sheet 2 Filed Aug. 8, 1958 niteol The present invention relates to resuscitation and more particularly to a device for blowing air into a patients lungs.

Although mouth-to-mouth resuscitation whereby air is blOWn into a patients lungs has been known for many years, recent work has clearly established that mouth-tomouth methods are substantially more eificient than any of the manual methods which depend upon physical compression of the chest wall. Among these are the backpressure arm-lift and chest-pressure arm-lift methods that have in recent years been taught as Standard firstaid treatment for patients requiring artificial respiration.

The average tidal volumes moved by the back-pressure arm-lift method as generally taught and applied in the field is only about 126 ml. of air. With mouth-tomouth methods, the tidal volumes moved is between 1000 ml. and 2000 ml. Out of victims studied, when using the conventional back-pressure arm-lift method, in 11 of the victims the tidal volumes of air moved was smaller than the estimated dead air space. With the mouth-to-mouth method, however, in all 15 victims studied the tidal volumes of air moved was between 1008 ml. and 2000 ml.

Despite this substantial improvement in artificial respiration by mouth-to-mouth resuscitation over that achieved by the back-pressure arm-lift method of artificial respiration or the other manual methods of artificial respiration, the average person has a natural instinctive aversion to placing his mouth over that of the patient. The idea of placing ones mouth on the mouth of an apparently dead victim, particularly where the mouth may be covered with foam, mucus or blood, as is often the ease in asphyxia victims, as well as the fear of possible transmittal of disease is revolting to the average person and is diiiicult to overcome. Since artificial respiration should be started immediately when the non-breathing victim. is found, a skilled physican is generally not present and the artificial respiration must be done by a layman. It is therefore highly desirable that the laymen, such as lifeguards, firemen, Boy Scouts and others, be provided with an instrument which makes mouth-tomouth resuscitation more acceptable and easier to perform.

In artificial respiration, it is vitally important that the head of the patent be in the proper position. The patients neck should be extended into a snifi'ing position, head back, and the mandible should be held upward. This aids in keeping the pharynx open. Studies have shown that the two principal causes of failure of the manual methods are (l) obstruction of the pharynx in the relaxed, unconscious patient from flexion or torsion of the neck and (2) too low a pressure gradiant to move air into patients with reduced lung-chest distensibility (e.g. obesity), or with partial air passageway obstruction.

it is an object of the present invention to make a simple, pocket size, compact device for respiratory resuscitation. It is a further object to make such a device, hereinafter referred to as an airway, which can be easily used by laymen with a minimum of training. It is also an object to make an airway of such design that it places the user in a position in which he can watch the patients chest and can hold the patients head and jaw in the proper position while artificial respiration is being applied. Other objects and advantages of this invention tates Patent will become apparent from the following description taken in connection with the accompanying drawings wherein are set forth by way of example certain embodiments of the invention.

The airway comprises a tube having one end adapted to enter a patients mouth and hold the tongue forward while the other end extends from the patients mouth into a position such that the user can readily blow through the tube while facing the chest of the patient and holding the patients nostrils closed, neck extended, and lower jaw upward. The portion of the tube passing into the patients mouth is curved and extends to the base of the patients tongue. A flange is provided at the proper distance from the end to limit the extent to which the tube is inserted. Also provided is a mask which fits over the patients mouth which may, if desired, be an integral part of the flange. The tube is preferably flattened on the inner side of the curve so as to lie flat on the patients tongue, helping to hold the tongue forward so that it will not block the air passageway. The airway is made with a double curve, giving it a somewhat S-shaped appearance. By having the end on which the rescuer blows curved back in the opposite direction to that of the curved endthat lies in the patients mouth, the rescuer is in position to watch the patients chest at all times, to hold the patients nostrils closed and to hold the patients head.

and mandible in the proper position.

The invention is further described by reference to the drawings in which a particular embodiment is illustrated. In the drawings:

FIG. 1 is a perspective view of an airway made in accordance with the present invention;

HO. 2 is a detailed view of the mouth mask and per tion of the airway tube to which it is attached.

FIG. 3 is a side view of the airway with a portion broken away;

FIG. 4 is a front view of the airway with a portion broken away;

FIG. 5 shows the insertion of the airway into the,

mouth of a patient;

FIG. 6 shows the airway in use; and

FIG. 7 is a top-plan view taken along line 7-7 of FIG. 6.

Referring to the drawings, the airway illustrated comprises a tube ll. having a somewhat flattened or elliptical cross section. The tube has two oppositely curved ends 12 and 13 separated by a straight section 14. The inner side of the curved ends 13 and 14 is relatively flat so as to lie along the tongue of a patient. The intermediate straight portion 14 of the tube is provided with a flange i5 and a raised ridge to, which serve to hold in place a mouth mask 17. Since the mouth mask is recessed as at 24 to receive the flange t5, the mouth mask can be conside'red as an extension of the flange 15, which would be the case if the whole were molded as a single piece.

The larger curved end 12, which is essentially the are of a circle having a radius of about 1 /2 inches, is adapted to be inserted into the mouth of an adult patient. The distance between the flange 15 and the end of the tube is such that the end of the tube, when inserted, is at the base of the patients tongue. The distance between the flange 15 and the tip of end 12. is therefore approximately the average linear distancebetween the outside of the lips of an average adult and the base of his tongue. In the airway illustrated, the distance between the tip 18 of the tube'and the flange 15 is 4 inches, which is'a safe length for use with the average adult patient.

The airway illustrated is primarily for use with adults. The end 13 is therefore the end into which the rescuer will usually be blowing. The end 13, however, must also be designed to be inserted into the mouths of children fortheir resuscitation. By curving this end backwards only a slight amount as shown and making this end substantially shorter, the end serves this dual purpose in a very eliicient manner.

The smaller end 13 of the tube has a slight curvature which is approximately that of an arc of a circle having a radius of about 1% inches. The end 19 of the tube is spaced about 2% inches from the flange 15. This length is found to be suitable for use with children ranging in age from about 3 to puberty. The flange 15, which coincides with the base of oral mask 17 on the straight portion of the tube, serves to limit the distance the tube is inserted into a patients mouth when the airway is in use. it is therefore important that the distance between the end of the tube and the flange is not too great. Since the mouth mask 17 is in essence a continuation of the flange 15 once the mouth mask has been attached to the tube, this is the same as saying that the distance between the base of the mouth mask and the tip of the tube should not be too great.

The air passage through the tube should be sufliciently large to offer little or no resistance to the blowing of the rescuer. It has been found that with a flattened tube of the type illustrated a ready flow of air can be obtained with an air passage having a width of about 18 to 20 mm. and a height of about 6 to 7 mm.

Besides the dimensions already given for the particular airway illustrated, the over-all length is about 6 /3 inches and the length of the straight intermediate section about 1% inches. The flange is, as illustrated, positioned about midway of the straight section 14.

It will be noted in the airway illustrated in the drawings that the walls of the tube are substantially thicker in the straight section 14 on either side of the flange 15. This serves to make the tube more rigid in this intermediate section and serves to prevent the patient from closing the tube by biting on the tube when in use. This strengthening may also be provided, if desired, by a metal insert rather than by thickening the Walls of the tube. It the tube is made of metal, such for example as stainless steel, this reinforcing is not necessary. However, metal tubes or tubes made of other materials having substantially the same rigidity as metal are generally not preferred except where they will he used by anesthetists or other similarly skilled persons because of possible injury to the patient during insertion.

The adult or larger end 12 is provided near its tip 18 with an opening 20 and 21 on each side and a third opening 22 on the back Wall. These openings prevent stoppage of the tube during use by providing extra openings which are available when the terminal opening may be blocked, thus making it substantially easier for the rescuer to blow air into the patients lungs or to allow for unobstructed spontaneous breathing. Because of the greater ease with which air can be blown into a childs lungs by a rescuer, it is not necessary to provide similar openings at the end 13 of the tube. Also, end 13 is the end blown into in rescuing an adult patient, where in some instances the rescuer has to blow quite hard. Openings at this end would make blowing into the tube in such instances substantially more difficult.

The oral mask 17 is formed of a flexible gas impermeable material and is curved so as to fit around a patients mouth and seal off any air that might otherwise escape when blowing into the patients lungs. The mask is elliptical in shape and besides being cupped so as to slope downwardly toward the edges from the center, it has a generally arcuate shape, curving down toward the ends. The mask, as shown, has a central opening 23 through which the tube 11 passes. Around the opening 23 is a recessed portion 24 into which the flange 15 is adapted to fit. The width of the mask around the edge of the opening 23 is such that the edge of the opening 23 fits snugly between the flange 15 and the ridge 16 provided on the tube 11 so that when the mask is inserted on the tube it will snap into place and remain there until [5. removed, the face mask 17 when attached being essentially an extension of flange 15. A mask found to be particularly suitable is one in which the major axis of its elliptical periphery is about 3% inches and its minor axis about 1% inches. The mask, however, is not limited to these specific dimensions. The mask may be made of any relatively impervious, flexible material, such as polyethylene, rubber, tetrafluoroethylene resins, etc. Where the material is sufliciently flexible, the mask can be inverted. that is, have its curvature changed to the opposite direction. For example, when the airway is used with a child, the oral mask can be cupped toward the end 13 by simply grasping the edges and pushing in on the center. This is particularly desirable where the mask is firmly secured to the airway and cannot be removed.

Although the mask has been shown as a separately molded item that is placed on the tube 11, it may be an integral part of the flange 15, i.e., the flange itself may be extended out to form the oral mask. It is generally preferred to form the mask of a material such that it can be inverted as above described and make the ridge '16 sufficiently tight that once the mask has been placed on the tube 11 it will remain there. However, if desired, the ridge may be sufliciently small to permit removal and reversal of the mask or removal of the mask when the airway is not in use so that it will more readily fit into the pocket or some other relatively small space.

The tube may be made of any material that is sufliciently rigid to permit insertion into a patient's mouth and is not brittle or toxic. As previously stated, it is generally preferred not to make the tube of a completely rigid material unless it is to be only used by an expert. However, there are numerous plastics and elastomers that have suiiicient rigidity and at the same time are sufficiently flexible. As an example of the Wide range of materials that may be employed, airways made of stainless stecl, hard rubber and polyethylene have all been used repeatedly and successfully in giving artificial respiration.

In the airway device shown in the drawings, both ends are so designed that either end may be inserted into the mouth of a patient. The larger end 12 is designed for insertion into the mouth of an adult patient while the smaller end 13 is designed for insertion into the mouth of a child patient (age 3 to puberty). The end not inserted into the patients mouth is directed back toward the top of the patients head so as to place the rescuer in the most ideal position for carrying out the artificial respiration. In this way, a single instrument may be used either with adults or children, making it unnecessary to carry a separate resuscitator for each.

The airway is of such design that only two airways are needed to cover the complete range from baby to adult, one airway being adapted to use with a child (age 3 to puberty) or an adult and the other airway being adapted to use with a child (age 1 to puberty) or a baby. For an adult, the distance from the end of the tube to the flange I5 is preferably -105 mm. for a child (age 3 to puberty) 65-75 mm. and for a baby 4050 mm. With airways adapted to be used only with babies and children, the curved mouth mask 17 may be omitted since the mouth can be adequately sealed by the thumbs or a flat flexible flange. This is possible because of the substantially smaller mouth size in relation to the tube diameter and also because inflations are less forceful. An airway designed primarily for infants would have openings near the tip of the infant end similar to those described in the drawings, while the other end would be free of such openings since it would in most cases be the end through which the doctor wouid blow.

The position of the patients head is important for obtaining the best results. In using the mouth-to-rnouth airway of the present invention, the rescuer places the patient supine, forces the patients mouth open with one hand and removes foreign material from the pharynx with the other hand. He then inserts the airway over the tongue, as illustrated in FIG. 5, being careful not to push the tongue back but to hold it forward. After insertion, the base of the mouth mask 17 of the airway must be at the level of the patients lips. Where the airway is adapted for adults and children, as in the airway illustrated, the long end 12 is inserted into the patients month if the patient is an adult. If the patient is a child, the short end 13 is inserted. The rescuer then blows on this protruding end, as illustrated in FIG. 6. For pediatricians and obstetricians, a single airway adapted for children and infants is particularly helpful. In using the airway, its short end would be inserted into an infants month while its long end would be used for children.

Once the airway is inserted, the procedure is as follows: From the patients vertex, looking downward at his chest, the rescuer extends the patients head and raises the jaw. With the thenar eminences of both hands he occludes the nose and prevents leakage through the corners of the mouth with the thumbs, as pictured in FIGS. 6 and 7, by pressing the mask 17 down over the mouth. The rescuer may improvise the prevention of air leakage as he likes, as long as the patients head remains in extension. For instance, the tips of the rescuers thumb may pinch the patients nose, while the second and third fingers press the mask over the lips and the fourth and fifth fingers pull on the horizontal rami of the mandible to hold the head extended. Also, one hand may be used to pinch the patients nose, while the palm of the other hand pushes the chin upward and the fingers press the oral mask or flange over the lips. The blowing into the artificial airway must be more forceful if there is air ieakage. The force of blowing necessary to adequately ventilate the patients alveoli can be determined by observation of the patients chest at all times. If the patients chest does not move in spite of proper snifling position, the rescuer shall withdraw the airway/slightly, or insert it deeper as the airway may not quite fit each patients pharynx.

For use in children, the airway may be turned around and the longer part used as a mouthpiece for the rescuer. The irflations must be gentle in children.

After a deep breath, the rescuer blows immediately into the mouthpiece-forcefully into adults, gently into children, and only with puffs from his cheeks into newborn infants. While blowing he must watch the patients chest constantly. When he sees the patients chest rise, he removes his mouth from the mouthpiece and permits the patient to exhale passively by the elastic recoil of the lungs and the chest wall. In emergency resuscitation, the immediate ventilation of the lungs is most important in order to prevent cardiac arrest and irreversible damage to the central nervous system. The first 10 to 20 breaths, therefore, must be deep and at a rapid rate. Later a rate between 12 to 20 per minute is satisfactory.

If the patients upper airway is poorly supported, for instance by flexion of the head, the higher inflation pressures necessary to overcome the partial obstruction may force air into the stomach. If the stomach becomes d-istended, gentle manual pressure over the patients epigastrium between breaths can expel the air.

Shallow spontaneous respirations can be assisted satisfactorily by the mouth-to-airway method: immediately following the patients initiation of each inspiration, the rescuer blows forcefully and briefly into the mouthpiece.

Extension of the head and forward displacement of the mandible are essential for patency of the natural air passageway in the unconscious patient (without a tube). It is relatively diflicult, without substantial training, to obtain proper forward dislocation of the mandible. In most instances, the use of a mouth- -month airway of the type described makes forward dislocation of the mandible unnecessary. These airways are therefore partici 6 ularly helpful where the rescuer is a layman with a minimum of training.

There are three primary areas where obstruction of the air passageway leading to the lungs of a patient may occur. These are the lips, the teeth and the pharynx. Obstruction of the pharynx by the relaxed tongue is common in the unconscious patient whose neck is flexed or whose mandible is sagging. With the patients head thrown back and chin up, the lips, teeth and pharynx are maintained open when an airway is inserted. The airway is thus extremely useful also in those cases where the patient may not need artificial respiration but may nevertheless strangle unless his air passageway is maintained open. This can be done by tilting the patients headback and inserting an airway of the type described. If it should become necessary to assist the patient in his breathing, an intern, nurse Or other attendant can then blow through the extending end of the airway as already described.

In view of the foregoing disclosures, variations or modifications will be apparent, and it is intended to include within the invention all such variations and modifications except as do not come within the scope of the claims. 7

Having thus described our invention, we claim:

1. An airway to be used by a rescuer for blowing air into a patients lungs while the patient is lying prone on his back comprising a tubular member having a substantially straight intermediate section, a flange adapted to remain outside of said patients mouth surrounding said intermediate section, a first extension from said intermediate section said first extension having a substantial curvature as compared to said intermediate section and terminating a distance of preferably about 65 to millimeters from said flange whereby when said first extension is inserted into the mouth of a patient and said flange engages his lips said first extension will extend inwardly and downwardly toward the base of the patients tongue to hold said tongue in a depressed position, and a second extension from said intermediate section, said second extension having a substantial curvature as compared to said intermediate section, the direction of curvature of said second extension being in a direction opposite to that of said first extension and the end of said second extension terminating at a distance from the base of said flange that is less than the distance from the base of said flange to the end of said first extension whereby a rescuer with his lower lip engaging the concave curved surface of said curved second extension for blowing air into the end of said second extension and through said airway into said patient is positioned at the head of said patient from where he can readily maintain the patients jaw and the airway in proper position while watching the patients chest to note the effect of said blowing, and whereby the functions of said ends may readily be interchanged when the airway is to be used with dimensions.

2. An airway of claim 1 wherein said relatively straight intermediate portion of said airway is reinforced.

3. An airway of claim 2.wherein said reinforcing is done by thickening the sides of said tubular member.

4. An airway of claim 1 in which the end portion of said first curved extension contains additional openings near the tip thereof.

5. An airway of claim 4 in which said openings comprise an opening on each side of said first curved extension and an opening extending through the convex curved surface thereof.

6. An airway to be used by a rescuer for blowing air into a patients lungs while the patient is lying prone on his back comprising a flexible tubular member having a relatively straight intermediate section, an ellipticallyshaped flexible flange surrounding said intermediate section adapted to fit outside of and over the mouth of a persons of much smaller physical patient to completely cover the same, a first extension from said intermediate section, said first extension having a substantial curvature as compared to said intermediate section and terminating at distance of preferably about 65 to 105 millimeters from the base of said flange where by when said first extension is inserted into the mouth of a patient and said flange engages his lips said first extension will extend downward toward the base of the patients tongue to hold said tongue in a depressed position, and a second extension from said intermediate section, said second extension having a substantial curvature as compared to said intermediate section, the direction of curvature of said second extension being in a direction opposite to that of said first extension and the end of said second extension terminating at a considerably less distance from said flange than the end of said first extension whereby a rescuer with his lower lip engaging the concave curved surface of said curved second extension for blowing air into the end of said second extension and through said airway into said patient is positioned at the head of said patient from where he can readily maintain the patients jaw and the airway in proper position while watching the patients chest to note the effect of said blowing, and whereby the functions of said ends may readily be interchanged when the airway is to be used with persons of much smaller physical dimensions.

7. An airway to be used by a rescuer for blowing air into a patients lungs while the patient is lying prone on his back comprising a flexible, tubular member having a relatively straight intermediate section, a flexible reversible mouth mask having an elliptically-shaped cross section and being cupped with its sides sloping downwardly towards its edges from its center, the sides along its major elliptical axis extending down further than its sides along its minor elliptical axis to give the peripheral rim of said mask a bowed shape in the direction of the major elliptical axis, a first extension from said intermediate section curved to a substantial angle from the axis of said intermediate section and terminating at distance of preferably about 65 to 105 millimeters from the base of said mask when secured to said intermediate section whereby when said first extension is inserted into the mouth of a patient and said flange engages his lips said first extension will extend downward toward the base of the patients tongue to hold said tongue in a depressed position, and a second extension from said intermediate section curved to a substantial angle in the opposite direction from said axis and terminating at a considerably less distance from said flange than the end of said first extension whereby a rescuer with his lower lip engaging the concave curved surface of said curved second extension for blowing air into the end of said second extension and through said airway into said patient is positioned at the head of said patient from where he can readily maintain the patients jaw and the airway in proper position while watching the patients chest to note the efiect of said blowing, and whereby the functions of said ends may readily be interchanged when the airway is to be used with persons of much smaller physical dimensions.

8. An airway of claim 7 in which said mouth mask is removable and has an opening through the center thereof through which said intermediate section is adapted to pass, said mouth mask being secured to said intermedi ate section by means of a pair of spaced ridges extending around said intermediate section, said ridges having an outer diameter larger than the diameter of said opening for maintaining said mask on said intermediate section when the edge of the mask at said opening is placed between said ridges and at least one of said ridges being sufficiently low to permit the edge of said mask at said opening to be passed over said lower ridge when placing said mask on said intermediate section, the space between said ridges being substantially the same as the thickness of said mask at its edge surrounding said opening to provide a seal between said cupped mask and said intermediate section of said tube when said mask is placed on said in termediate section whereby leakage of air between said mask and said intermediate section is prevented during use of said airway.

9. An airway of claim 7 in which said mask is made of a flexible material sufficiently rigid to maintain a cupped form when the center is pushed in so as to invert the same.

10. An airway to be used by a rescuer for blowing air into a patients lungs while the patient is lying prone on his back comprising a flattened, flexible, tubular member having a relatively straight, reinforced intermediate section, a pair of spaced ridges extending around said intermediate section about midway thereof, an ellipticallyshaped, cupped mouth mask rcmovably positioned on said intermediate section between said spaced ridges, the outer edge of said mask curving downwardly along its major axis toward its ends and said mask having a centrally disposed opening through which said tube is inserted when said cupped flange is placed thereon, said ridges having an outer diameter larger than the diameter of said opening for maintaining said mask on said intermediate section when the edge of the mask at said opening is placed between said ridges, and at least one of said ridges being sufiiciently low to permit the edge of said mask at said opening to be passed over said lower ridge when placing said mask on said intermediate section, the space between said ridges being substantially the same as the thickness of the mask at its edge surrounding said opening to provide a substantially air-tight seal between said mask and said intermediate section of said tube when said flange is placed on said intermediate section whereby leakage of air between said flange and said intermediate section is prevented during use of said airway, a first extension from said intermediate section curved in the flattened plane of said tube to a substantial angle from the axis of said intermediate section and terminating a distance of preferably about 65 to millimeters from said ridges whereby when said first extension is inserted into the mouth of a patient and said mask engages his lips said first extension will extend downwardly toward the base of the patients tongue to hold said tongue in a depressed position, and a second extension from said intermediate section curved to a substantial angle in the opposite direction from said axis and terminating at a considerably less distance from said ridges than the end of said first extension whereby a rescuer with his lower lip engaging the concave curved surface of said curved second extension for blowing air into the end of said second extension and through said airway into said patient is positioned at the head of said patient from where he can readily maintain the patients jaw and the airway in proper position while watching the patients chest to note the effect of said blowing, and whereby the functions of said ends may readily be interchanged when the airway is to be used with persons of much smaller physical dimensions.

11. An airway to be used by a rescuer for blowing air into a patients lungs through his month while the patient is lying prone on his back comprising a tubular member having a relatively straight intermediate section, a flange adapted to remain outside of said patients mouth, surrounding said intermediate section, a first extension from said intermediate section curved so as to lie in an arc to which said straight section would form a cord if continued and terminating a distance of preferably about 65 to 105 millimeters from said flange whereby when said first extension is inserted into the mouth of a patient and said flange engages his lips said first extension will extend inwardly and downwardly toward the base of the patients tongue to hold said tongue in a forward and depressed position, and a second extension from said intermediate section curved so as to lie in an arc to which said straight section would form a cord if continued and in a direction opposite to the direction of curvature of said first extension, the said second extension terminating at a distance from said flange that is less than the distance from the base of said flange to the end of said first extension whereby a rescuer with his lower lip engaging the concave curved surface of said curved second extension for blowing air into the end of said second extension and through said airway into said patient is positioned at the head of said patient from where he can readily maintain the patients jaw and the airway in proper position while watching the patients chest to note the effect of said blowing, and whereby the functions of said ends may readily be interchanged when the airway is to be used with persons of much smaller physical dimens1ons.

References Cited in the file of this patent UNITED STATES PATENTS 1,270,565 Teter June 25, 1918 OTHER REFERENCES Washington Post, Sept. 28, 1958, article by Nate 10 Haseltine and picture, copy in 128-29.

Anesthesiology, Volume 18, No. 6 November-December, 1957. Mouth-to-Mouth Airway.

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