Fiber Optic Entubator And Method Of Entubation Of The Trachea Through The Nasopharynx

Abstract

An entubator for an endotracheal tube which includes a coherent flexible fiber optic bundle which can be positioned within the central cavity or lumen of the endotracheal tube for viewing the anatomy of a patient as the endotracheal tube advances through the patient during the insertion procedure. The entubator also includes a means for directing the course of travel of the endotracheal tube which enables the operator to navigate the endotracheal tube through anatomical passageways made visible by the fiber optics bundle. The fiber optic bundle and the means for directing the course of travel enable the entubation of an endotracheal tube through the nasopharynx of the patient. Method of entubing an endotracheal tube through the nasopharynx.

Description

BACKGROUND OF THE INVENTION

The field of this invention is a therapeutic instrument for treating patients who require mechanical ventilation.

It is a standard medical procedure to insert an endotracheal tube into patients who are unable to breathe for themselves because of diseased states to provide mechanical ventilation. For example, when a patient has suffered a heart attack, a stroke, severe pneumonia, or an epileptic seizure, mechanical ventilation may be required and thus an endotracheal tube is often inserted into the patient having these diseased states. The insertion of such a tube is also a standard medical procedure which is performed whenever general anaesthetics are administered or whenever routine surgery is required.

The standard method for performing an entubation of an endotracheal tube is to place the patient in a prone position, tilt his head backwards as far as possible, and insert a metal laryngoscope through the patient's mouth. The endotracheal tube is then passed alongside the metal laryngoscope and while the patient's vocal cords are viewed through the laryngoscope, the tube is passed through the vocal cords.

The foregoing procedure is painful and requires either general and/or local anaesthetics. Furthermore, well recognized complications arising from the use of the metal laryngoscope include neck fractures, aspiration of vomit into the lungs, jaw fracture, and the breakage of teeth during insertion of the laryngoscope. In addition to the foregoing disadvantages, the procedure described above is difficult to perform in patients who are obese, who have malformations of the jaw, or who have a disease or fractures of the cervical spine. In fact, it is so difficult to entube an endotracheal tube with a laryngoscope that death has occurred in some patients during the attempt to place the endotracheal tube into the trachea. Such deaths have occurred because of the insufficient flexibility and capability of the laryngoscope to rapidly and quickly place the tube into the trachea.

When the endotracheal tube cannot be placed into the trachea with the use of the metal laryngoscope, it is common medical procedure to perform a tracheostomy. A tracheostomy consists of cutting a hole in the base of the neck and inserting a breathing tube into the trachea through the hole.

The foregoing disadvantages are greatly reduced by utilizing the entubator of the present invention which is capable of inserting the tube into the trachea through the patient's nasopharynx while the patient's head rests in a natural position without using a laryngoscope and without causing significant trauma to the patient. Entubment is faster, safer and easier to perform using the entubator of the present invention than entubment using instruments such as the laryngoscope.

Such an entubation is possible with the entubator of the present invention because the entubator includes a means, in the form of a flexible coherent fiber optic bundle within the endotracheal tube itself, for viewing the anatomy of the patient as the endotracheal tube advances into the nasopharynx and a means for directing and controlling the course of travel of the endotracheal tube to avoid obstructions which are made visible through the fiber optics bundle and thus enable the operator to navigate the tube through the natural passageway formed by the nasopharynx.

The medical literature is replete with references disclosing medical devices which include coherent flexible fiber optic bundles, or fiberscopes as they are often called.

Representative of such devices is the well known fiber optic bronchoscope which is a diagnostic instrument and which comprises a rubber tube containing light guides in the form of flexible fiber optic bundles and a tip which is remotely controllable to increase the field of view once the instrument is inserted into a patient. Although this instrument includes a flexible fiber optic bundle, that bundle's function begins once the tube is inserted. In this regard, the manufacturers of these instruments recommend that the instrument be inserted through a straight metal tube bronchoscope or through an endotracheal tube which has been inserted into a patient with a metal laryngoscope. Thus, the flexible fiber optic bundle is not intended to facilitate the insertion of the instrument.

Although the fiberscope portion of the fiber optic bronchoscope was not designed nor intended to function as a means for facilitating insertion of the instrument, applicant has devised a procedure for performing bronchoscopies where the fiberscope portion of the fiber optic bronchoscope does in fact function as a means for facilitating the insertion of the instrument. Since this procedure has many similarities to the present inventive method of entubing endotracheal tubes, it is amplified below in connection with the entubment procedure of the present invention.

Although the literature contains many publications disclosing medical instruments which include fiberscopes, very few instruments are disclosed or are shown in which the fiberscope system of the instrument actually is utilized as an aid to facilitate insertion of the instrument itself.

A patent which discloses an instrument where a fiber optic system is utilized to facilitate insertion of the instrument is U.S. Pat. No. 3,572,325 to Bazell et al. entitled "Flexible Endoscope Having Fluid Conduits and Controls." The device disclosed in the Bazell et al. patent is an adaptation of a sigmoidoscope which is flexible and which includes a fiber optic system and a control assembly to navigate the distal tip of the instrument into a patient's colon. It should be noted, however, the the instrument disclosed in the Bazell et al. patent is an adaptation of a previously existing instrument, a sigmoidoscope, and unlike the instrument of the present invention is designed and intended to enter into a patient's body through the same anatomical passageway as the sigmoidoscope of which it is an adaptation would enter. Furthermore, the advantages of providing a flexible sigmoidoscope had been long recognized, particularly since the colon into which the instrument is inserted has a natural configuration which renders straight rigid instruments undesirable.

In the device disclosed in the Bazell et al. patent, the fiber optic system and control assembly facilitate the insertion of this flexible instrument. As stated above, however, providing flexibility features on this type of instrument were known to be desirable.

It should, of course, also be noted that although there is some similarity between the device of the present invention and the Bazell et al device in that the Bazell et al device, as well as the device of the present invention, includes a fiber optic system for viewing the passageway during the insertion of the instrument and control means for navigating the instrument in response to the view of the passageway made visible by the fiber optic system, the device of Bazell et al could never serve as a means for entubing an endotracheal tube through any opening in the body let alone through the nasopharynx. In this regard, it is the entubment of the endotracheal tube through the nasopharynx and into the trachea toward which the present invention is directed.

Also representative of prior art medical instruments which include fiberscopes as a part of the instrument are the devices disclosed in U.S. Pat. No. 3,434,775 to N. R. Gosselin entitled "Flexible Fiber Optic Borescope" and the device disclosed in U.S. Pat. No. 3,494,354 to Ryosuke Yokota et al. entitled "Flexible Endoscope for Use in Cancer Diagnosis." These patents, however, are not believed to be pertinent to the present invention.

SUMMARY

Many of the disadvantages of the prior art entubators for endotracheal tubes are overcome by the method and device of the present invention which involves an entubator for an endotracheal tube which enables insertion of an endotracheal tube into the trachea through the patient's nasopharynx.

Accordingly, it is an object of the present invention to provide a new and improved entubator for placing an endotracheal tube into the trachea.

A further object of the invention is to provide an entubator with which an endotracheal tube can be inserted into the trachea without the use of a laryngoscope.

A further object of the present invention is to provide an entubator for an endotracheal tube which can entube an endotracheal tube into the trachea through the patient's nasopharynx.

Another object of the present invention is to provide an entubator for an endotracheal tube which enables the entubation of the endotracheal tube while the patient's head rests in a natural position.

Another object of the present invention is to provide an entubator for an endotracheal tube which enables the entubation of the endotracheal tube without tilting the patient's head backwards.

Another object of the present invention is to provide an entubator for an endotracheal tube which can entube an endotracheal tube into patients who have fractures of the cervical spine without performing a tracheostomy.

A further object of the present invention is to provide a new and improved device for the examination and evacuation of the trachea.

Still another object of the present invention is to provide a new method for entubing an endotracheal tube into the trachea.

A further object of the present invention is to provide a method for entubing an endotracheal tube without the use of a laryngoscope.

Another object of the present invention is to provide a method for entubing an endotracheal tube while the patient's head rests in a natural position.

Another object of the present invention is to provide a method for entubing an endotracheal tube without tilting the patient's head backwards.

Another object of the present invention is to provide a method for entubing endotracheal tubes in patients who have fractures of the cervical spine without performing a tracheostomy.

Still another object of the present invention is to provide a method for entubing an endotracheal tube into a patient's trachea through the patient's nasopharynx.

A further object of the present invention is to provide a new and improved method for the examination and evacuation of the trachea.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is a side elevational view partially in section of an entubator in accordance with the present invention positioned within an endotracheal tube;

FIG. 2 is a transverse sectional view, on an enlarged scale, taken along line 2--2 of FIG. 1;

FIG. 3 is a longitudinal sectional view taken along line 3--3 of FIG. 2;

FIG. 4 is a perspective view showing entubment of an endotracheal tube with the entubator of FIG. 1 in a patient through the patient's nasopharynx; and

FIG. 5 is a side elevational view of an embodiment of an entubator in accordance with the present invention positioned within an endotracheal tube.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

As stated above, the insertion of tubes into patients through the patient's mouth has resulted in a number of significant problems.

After considering these problems, applicant concluded that one way to provide greater safety and less discomfort for the patient during entubment would be to utilize a flexible entubator with a built in viewing system. However, even with such a flexible entubator, complications still occur when the flexible instrument is inserted into the patient through the patient's mouth.

In particular, when any instrument, whether flexible or not, is placed on the back of a patient's mouth, a strong gagging sensation results. Furthermore, it is difficult to anaesthesize against this gagging sensation. This complication creates problems because a patient's normal response to this gagging sensation is a motion of the tongue which displaces the instrument. It, of course, can be easily appreciated that such displacement of the instrument is undesirable.

Another complication resulting from passage of an instrument through the mouth is that a patient has a tendency to bite the instrument. This tendency has a deleterious effect on fiberscopes in that biting disturbs the transmission of an image through the fiberscope and can damage the fibers in the fiberscope. Thus, a fiberscope which is inserted into a patient's mouth is normally shielded against possible damage from biting. Such shields, however, can reduce the advantage gained by the flexibility properties of the fiberscope since such shields are not normally as flexible as the fiberscope.

After considering these problems, applicant conceived of by-passing the mouth completely by inserting a flexible instrument into the trachea through the nasopharynx. To test this procedure, applicant passed a fiber optic bronchoscope into the trachea through the nasopharynx and has repeatedly utilized this technique involving transnasal passage of this instrument for the diagnosis of pulmonary disease.

Broadly, this technique is accomplished by spraying local anaesthetics directly into the nose and throat, lubricating the distal end of the bronchoscope with an anaesthetic jelly and thereafter passing the flexible fiber optic bronchoscope through the nasopharynx into the trachea while the passageway of the nasopharynx is viewed through the bronchoscope itself.

In the preferred procedure for transnasal passage of the instrument, the patient's nose and throat are sprayed with one-quarter per cent tetracaine solution. The distal end of the instrument is coated lightly with anaesthetic jelly. The instrument is passed through the nasopharynx under direct visualation. The instrument is placed over the vocal cords and they are sprayed with local anaesthetic, after which the instrument is passed on into the trachea. Examination of all segments of the bronchial tree is carried out with the patient seated with his head in a resting position.

Patient acceptance of this procedure has been excellent and there have been no significant complications. The flexible bronchoscope is of utmost utility in the performance of diagnostic bronchoscopy on patients with cervical osteoarthritis; cervical fractures, aortic aneurysm, bleeding and clotting disorders, hypoxia, and other situations where standard bronchoscopy with the rigid bronchoscope might be contraindicated.

Since a skilled physician is familiar with the anatomy of the transnasal passageway of the nasopharynx, an instrument can be guided, manipulated, or navigated through the passageway if the passageway is viewed during the insertion of the instrument. Of course, this factor presents no problem in the case of fiber optic bronchoscopes since a fiber optic viewing system is contained in this instrument.

Applicant has presented this procedure in papers delivered before several national medical meetings. The first paper on the transnasal passage of a fiber optic bronchoscope through the nasopharynx was delivered by applicant at The Thirtieth Veterans Administration-Armed Forces Pulmonary Disease Research Conference in Cincinnati, Ohio, on Jan. 26, 1971. A report on the paper delivered at that conference appears on page 865 of the publication "American Review of Respiratory Disease," Vol. 103, No. 6, June 1971, the teachings of which are herein incorporated by reference.

On Oct. 26, 1971, at the Third Fall Scientific Assembly of the American College of Chest Physicians, applicant delivered a similar paper directed to the transnasal passage of a fiber optic bronchoscope. An abstract of the paper delivered at that assembly entitled "The Utility of the Flexible Fiberoptic Bronchoscope" appears in the publication "Chest," Vol. 60, No. 3, Sept. 1971, pages 303-304, the teachings of which are also herein incorporated by reference.

Having found that transnasal passage of a fiber optic bronchoscope clearly reduced many of the problems attendant with oral passage of this instrument, applicant concluded that many of the problems attendant with oral passage of an endotracheal tube would also be greatly reduced by transnasal passage of the endotracheal tube itself.

To demonstrate the foregoing, applicant constructed a test model entubator for entubing an endotracheal tube through the nasopharynx and entubed a number of endotracheal tubes in various patients with this test model entubator by passing the endotracheal tubes through the patient's nasopharynx into the trachea.

The test model entubator used in these entubments and an endotracheal tube are shown in FIGS. 1-4 of the drawing. In FIGS. 1-4, an endotracheal tube is generally designated by reference numeral 10. Endotracheal tube 10 is a standard commercially available endotracheal tube formed of a flexible hard rubber, is tubular, arcuate in shape and has a hollow metal connector 12 fitted into the inner wall of tube 10 at its proximal end 14. Once the tube is positioned in the trachea, the metal connector 12 provides the means for connecting the air line of a mechanical ventilator (not shown) to tube 10 to deliver air through the endotracheal tube to the patient.

For most applications, endotracheal tube 10 is fitted with a rubber cuff (not shown). The rubber cuff, which is inflatable, is slipped over distal end 16 of tube 10 prior to entubment. The purpose of the inflatable rubber cuff is to prevent leakage of air around the outside of the endotracheal tube once the endotracheal tube is placed in the trachea. Such leakage is prevented by inflating the cuff after the tube including the cuff is inserted into the trachea. However, since the features of such a cuff are well known in this art and since its use has no connection with the present invention, the cuff is not shown in the drawing, although in the entubments described below, the endotracheal tubes were fitted with such a cuff.

The test model entubator used in various tests in which tube 10 was entubed into patients by passing the tube through their nasopharynx and into their trachea comprised a viewing means for viewing the anatomy of the nasopharynx as the tube passed therethrough and a means for directing the course of travel of the endotracheal tube to avoid obstructions made visible by the viewing means. In the test models constructed for these tests, the viewing means utilized was a commercially available fiber optic bronchoscope generally designated in FIGS. 1-4 by reference numeral 18. The fiber optic bronchoscope used in these tests was an Olympus Model BF fiberscope. This instrument has a transmission cable 19 with a working length of 55.7 cm, an outside diameter of 5 mm and a remotely controllable tip which moves through a range of 130.degree. upward and 30.degree. downward. The mechanism for moving the tip of cable 19 which is a tension wire is not shown in the drawing since the details of this mechanism are well known in this art. Furthermore, that mechanism is not capable of causing any useful movement of endotracheal tube 10 because that mechanism is only designed to move cable 19 which has little resistance or resiliency. In this regard, endotracheal tube 10 offers too much resistance to enable this mechanism to move tube 10 through the distances required to accomplish the objects of this invention.

Fiber optic bronchoscope 18 also contains a lens (not shown) positioned over the distal end of image transmitting bundle 32. This lens enables an 83.degree. forward field of view with a depth of focus of from 5 to 45 mm.

Transmission cable 19 of bronchoscope 18 also contains a 1 mm suction channel 21. Channel 21 is open at distal end 26 and the other end is connected to a connector or nipple 23 formed in handle 40 of the bronchoscope. During the entubment procedure, a local anaesthetic is injected into the patient from a syringe which is attached to connector 23.

Because of the small diameter of transmission cable 19, it is easily positioned within cavity or lumen 20 which is formed by inner wall portion 22 of tubular wall 24 and the inner wall portion of metal connector 12. As is shown in FIG. 1, cable 19 is positioned so that it extends into and through the entire length of the lumen of tube 10, from its proximal end 14 to its distal end 16. Since the diameter of that portion of cavity or lumen 20 formed by inner wall portion 22 is approximately 9 mm, a reasonably good fit results when cable 19 with an outside diameter of 5 mm is positioned within tube 10. In the test models, cable 19 was positioned within tube 10 so that the distal end 26 of cable 19 extended just beyond the distal end 16 of tube 10, as is shown in FIG. 1. Thus, the viewing means of the entubator of the present invention is positioned within the lumen of the endotracheal tube.

In the test models, the means for directing the course of travel of tube 10 comprised a thin nylon line 28. Prior to insertion of cable 19 into endotracheal tube 10, line 28 was passed into cavity 20 so as to run through the inside of the entire length of tube 10. The two ends of line 28 were then knotted outside of the tube as is shown at 29 to form a loop, part of which extended through the lumen of tube 10. Line 28 was knotted in a manner so as to allow sufficient slack to permit endotracheal tube 10 to remain in its natural arcuate configuration when no pressure was exerted along line 28. It should be noted that the size of line 28 is greatly exaggerated in the drawing. A suitable line is 6 lb. test nylon monofilament line with a diameter which is less than 0.5 mm.

Since endotracheal tube 10 is arcuate in shape, a downward force applied at about point 31 in the direction of arrow 33, causes a downward displacement of the distal end 16 of the arc formed by the endotracheal tube. With tube 10 positioned as is shown in solid lines in FIG. 1, such displacement of tube 10 is in the plane of the drawing and is along the route indicated in FIG. 1 by arrow 35 from the natural position of tube 10 shown in solid lines to the position shown in dotted lines. To apply such force during entubment, the operator places his finger at location 31 through the loop formed by line 28 and applies a gentle force in the direction of arrow 33, thus displacing the position of endotracheal tube 10. As suggested above, line 28 enables displacement in one plane. However, in the tests, such displacement of endotracheal tube 10 proved to be satisfactory to enable entubment through the patient's nasopharynx since displacements in directions other than the one shown in the drawing are possible by turning the endotracheal tube during entubment to cause the distal end 16 of tube 10 to point in the general direction toward which displacement is desired. Thus, by a combination of turning endotracheal tube 10 and applying a force along line 28 in the direction of arrow 33, it was possible to navigate the endotracheal tube through the passageway formed by the nasopharynx.

Further details of fiber optic bronchoscope 18 are shown in FIGS. 2-4 and include an image transmitting bundle 32, light source bundle 34 and a flexible suction channel 21, all of which are enclosed by a flexible plastic tubular covering 36. Although in FIGS. 2 and 3 bundles 32 and 34 appear as if they are solid rods, it should be understood that bundles 32 and 34 are each comprised of a plurality of minute light guiding fibers. Such fibers have diameters that may be just one-tenth the diameter of a human hair. Both bundles 32 and 34 are flexible. The fibers which comprise the flexible image bearing bundle 32 are arranged to be coherent so that an image cast upon the face of the bundle at distal end 26 is reproduced upon the face at the opposite end of the bundle. Since the light source bundle 34 does not transmit an image, flexible bundle 34 need not be coherent. It should be understood, however, that light source bundle 34, if coherent, would function to conduct light but the cost of manufacturing and assembling coherent bundles exceeds the cost of manufacturing non-coherent bundles. Since the only function of bundle 34 is to conduct light, this bundle is not normally coherent. The fibers which comprise both bundles 32 and 34 are formed of a transparent material such as glass and operate on the principle of total internal reflection. This principle is so well known that it requires only a brief description. A transparent elongated smooth-surfaced body of higher refractive index than its surroundings can transmit light applied to one end so that it emerges with little loss at the other end, due to total internal reflection from its surfaces, of light rays divergent from the longitudinal axis of the body. To produce total internal reflection within each fiber, each fiber is formed of a central glass core surrounded by a thin sheath or cladding of glass having a lower refractive index than the core. Although glass fibers are preferred, light guiding fibers may be formed of transparent plastics. However, the construction of bundles of light guiding fibers from either glass or plastic is well within the skill of those in this art.

The transmission cable 19 comprised by covering 36, bundles 32 and 34 and channel 21 extended to and into handle 40 of bronchoscope 18. The image transmitting bundle 32 passes through handle 40 to an eye piece 42. Light source bundle 34 passes through the side of handle 40 and is enclosed by a protective plastic covering 41. The assembly comprised by covering 41 and bundle 34 is connected to a fiber optic illuminator (not shown). Light from the illuminator is conducted through the fibers in bundle 34 to the distal end 26 of cable 19 to enable the scene to be viewed through bundle 32 to be illuminated.

The first entubment of an endotracheal tube utilizing the foregoing entubator is shown in FIG. 4 and was performed on a patient who had suffered respiratory failure and required mechanical ventilation.

With the patient seated in bed, his head was placed in a comfortable position and his nose was then sprayed with a local anaesthetic while he remained seated in an upright position in his bed. A suitable local anaesthetic which can be used for this step is a 1 per cent xylocaine solution.

A nylon line was then looped through the lumen of an endotracheal tube and knotted in the manner which is described above and which is shown in FIG. 1. The distal end of the endotracheal tube was lubricated with an anaesthetic jelly and thereafter about one-half of an inch of the distal tip of the tube was inserted into the patient's nose. A suitable anaesthetic jelly which can be used to lubricate the tube is xylocaine jelly. With the tip of the endotracheal tube inserted slightly into the patient's nose a fiber optic bronchoscope was then inserted through the lumen of the endotracheal tube so that the distal end of the bronchoscope extended just beyond the distal end of the endotracheal tube as is shown in FIG. 1 so that the passage of the endotracheal tube through the nasopharynx could be observed.

In this entubment procedure, the endotracheal tube with the looped nylon line were placed into the patient's nose prior to the insertion of the fiber optic bronchoscope. Alternatively, the bronchoscope and nylon line can be assembled within the endotracheal tube as is shown in FIG. 1 prior to the insertion of the endotracheal tube into the patient's nose. Whether this technique is utilized or whether the foregoing technique is utilized is merely an operator's preference. The important point, however, is an endotracheal tube cannot be safely inserted very far into a patient's nasopharynx without the operator being able to see the natural passageway of the nasopharynx.

With the entubator assembled, the endotracheal tube was then manually navigated through the nasopharynx while the passage of the tube was viewed through the fiber optic bronchoscope. As the natural anatomical passageway formed by the nasopharynx was observed through the fiber optic bronchoscope, that passageway was navigated by flexing the distal end of the endotracheal tube by pulling the looped nylon line, by turning the endotracheal tube so that the end of the tube pointed in the general direction of the passageway, or by a combination of turning and flexing the distal end of the tube. After the distal tip of the tube was pointed in the desired direction, the operator gently pushed the tube into the passageway. If any obstructions in the nasopharynx were viewed, such obstructions were cleared in the same manner.

When the patient's vocal cords were visualized, a local anaesthetic solution was passed through the channel of the bronchoscope onto the vocal cords.

To anaesthetize the vocal cords, a 1 percent xylocaine solution is put into a syringe. The syringe is then connected to the nipple or connector on the bronchoscope. The xylocaine solution is then delivered from the syringe and after passing through the channel is sprayed on the vocal cords.

After allowing sufficient time (about 3 minutes) for the anaesthetic to take effect, the endotracheal tube was pushed through the vocal cords while the vocal cords were viewed through the bronchoscope. After passing the tube through the vocal cords the tube was positioned in the trachea.

Once the endotracheal tube was positioned in the trachea, the fiber optic bronchoscope and the nylon line were removed. The endotracheal tube was then connected to a mechanical ventilator to provide the ventilation required by the patient.

Endotracheal tubes were positioned in 10 patients by passing the endotracheal tube through the nasopharynx in accordance with the present invention. The patients in whom tubes had been inserted in this manner tolerated the procedure very well. The patients' response was considered good and there were no complications noted from this procedure. As compared to the prior art method of oral entubment with a laryngoscope, by following the present invention there was an increase in the speed of passage of the tube. Such increased speed of passage decreased the amount of pain normally incurred by a patient when endotracheal tubes are entubed with a laryngoscope.

At this point it should be noted that endotracheal tubes have in the past been passed through the nasopharynx. Such passage has been accomplished by using one or two known techniques. The first technique is to blindly stuff the endotracheal tube through the nasopharynx into the trachea. This technique is not considered to be satisfactory since the passage of the tube through the nasopharynx cannot be observed and is normally performed only in emergency situations. The other prior art technique for passing an endotracheal tube through the nasopharynx is to use a laryngoscope which is placed in the patient's mouth to illuminate the vocal cords. This technique has many deficiencies when compared to the method of the present invention. In particular, all the disadvantages arising from oral passage of the endotracheal tube with the use of a laryngoscope are still present when a laryngoscope is employed. Merely by way of example, the patient's head must be tilted back in order to insert the laryngoscope. In addition, this procedure is not acceptable because the passage of the nasopharynx cannot be viewed.

It should be noted that the entubator described above was constructed to demonstrate that endotracheal tubes could be safely entubed into the trachea through a patient's nasopharynx. In this regard, the entubator described above was capable of successfully entubing endotracheal tubes in a number of patients by passing the endotracheal tube into the patient's nasopharynx. It is here emphasized, however, that the entubator described above is merely a demonstration model constructed from components that were readily available to enable the foregoing tests. That model, however, was sufficient to indicate the essential components necessary for carrying out the objects of this invention. Those components include a viewing means for enabling the observation of the natural passageway formed by the nasopharynx, a means for navigating the endotracheal tube through that passageway and a conduit or channel for delivering an anaesthetic into the patient as required during entubment. All of these components are preferably assembled to form an entubator which can be positioned within the lumen of the endotracheal tube.

A more sophisticated embodiment of the invention which contains the foregoing essential elements is shown in FIG. 5 of the drawing. In FIG. 5 the entubator is generally designated by reference numeral 50 and is shown positioned within the lumen of an endotracheal tube 10. The endotracheal tube 10 shown in FIG. 5 is identical to the endotracheal tube shown in FIG. 1. The viewing means for entubator 50, like the viewing means of the bronchoscope shown in FIGS. 1-4, is comprised of a coherent flexible fiber optic image transmitting bundle and a flexible light source illuminating bundle, both of which are enclosed in a plastic covering 52. The image transmitting bundle extends throughout the length of covering 52 to the distal end 54 of the entubator whereupon it is capped by an appropriate lens for viewing the anatomy of the nasopharynx. The proximal end of the image transmitting bundle extends through handle 56 and is optically connected to an eye piece 58 to enable the operator to view images focused by the lens on the distal end of the image transmitting bundle. The light source bundle also passes throughout the inside of the protective cover 52 to the distal end of the entubator. The light source bundle then passes through handle 56 of entubator 50 at 60 where it is protected by a plastic covering 62. The light source bundle within covering 62 is then connected to a fiber optic illuminator (not shown), thus enabling the illumination of the image to be viewed by the image transmitting bundle. Also extending through the entire length of covering 52 is a conduit or channel 64. Channel 64 is open at the distal end 54 of the entubator and passes through handle 56 of the entubator and is connected to a connector 66 to which in turn is connected a suction line 68. For delivering local anaesthetic to the patient from the distal end of the entubator, suction line 68 is removed and a syringe is connected to connector 66. Delivery of the anaesthetic with this embodiment is identical to the delivery discussed above in connection with the embodiment shown in FIGS. 1-4. Running along the inside wall of covering 52 is a tension wire 70. Tension wire 70 is anchored to the covering 52 at the distal end of the entubator and runs along the inside wall of covering 52 into handle 56 whereupon it passes through the handle and is connected to a ring or trigger 72. Tension wire 70 may be constructed in the same manner as the tension wire used to remotely control the tip of cable 19 of bronchoscope 18 with the exception that tension wire 70 must be capable of exerting a force sufficient not only to remove the distal end 54 of the entubator but also be sufficient to move the endotracheal tubes through the distance required to accomplish the objects of this invention. It should, of course, be immediately appreciated that in an alternate embodiment of the invention a tension wire or any other means for moving the endotracheal tube may be built right into an endotracheal tube itself.

A transverse sectional view of entubator 50 is not shown in the drawing but it should be appreciated that such a view would be similar to the transverse sectional view of bronchoscope 18 shown in FIG. 2 of the drawing.

With the type of entubator shown in FIG. 5, the working length of the fiber optic bundles need not be as long as the working length of the bundles in cable 19 of bronchoscope 18. Preferably, the length of the entubator should only be long enough so that when inserted in an endotracheal tube, handle 56 of the entubator is in close proximity to the proximal end 74 of metal connector 12 with distal end 54 extending just beyond distal end 16 of tube 10. The diameter of the assembly enclosed by covering 52 must be small enough so that the assembly can be positioned within the lumen of the endotracheal tube as is shown in FIG. 5. However, the fit must be loose enough to enable easy removal of the entubator from the tube after insertion of the tube into the patient without significantly disturbing the position of the tube in the patient's trachea.

The invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

Claims

I claim:

1. An entubator for entubing an endotracheal tube in a patient's trachea through the patient's nasopharynx comprising a viewing means for enabling the operator to view the passageway of the nasopharynx as the endotracheal tube advances therethrough, said viewing means being capable of being positioned within the lumen of the endotracheal tube and transmitting to the operator a view of the passageway formed by the nasopharynx when the endotracheal tube with said viewing means so positioned is in the nasopharynx and a directing means for directing a force applied at a point remote from the distal end of the endotracheal tube to remove the distal end of the endotracheal tube sufficiently to enable the operator to point the distal end of the endotracheal tube into the nasopharynx as the endotracheal tube advances therethrough, both said viewing means and said directing means being capable of being combined with an endotracheal tube and bending sufficiently to conform to the passageway formed by the nasopharynx so that the operator can navigate the endotracheal tube through the nasopharynx by moving the distal end of the endotracheal tube so that it points into the nasopharynx as the passageway of the nasopharynx is viewed by the operator during entubment.

2. The entubator as set forth in claim 1 wherein said viewing means is a flexible coherent fiber optic bundle.

3. The entubator as set forth in claim 2 also comprising a channel which is capable of being positioned within the lumen of the endotracheal tube along with said bundle for delivering a local anaesthetic to the patient during the entubment procedure.

4. The entubator as set forth in claim 3 wherein said bundle and said channel is enclosed in a flexible covering and wherein said directing means is a tension wire anchored to said covering, said tension wire being capable of moving the entubator with sufficient force to cause the distal end of the endotracheal tube to point into the nasopharynx as the endotracheal tube advances therethrough when said entubator is positioned in said endotracheal tube and when a force is applied and directed along said tension wire.

5. The entubator as set forth in claim 2 wherein said directing means is attached to the endotracheal tube.

6. The entubator as set forth in claim 2 wherein said directing means is contained in the entubator.

7. An endotracheal tube which can be entubed in a patient's trachea through the patient's nasopharynx, said tube containing a flexible coherent fiber optic bundle positioned within the lumen of the endotracheal tube for transmitting to the operator a view of the passageway formed by the nasopharynx as the endotracheal tube advances therethrough, a directing means for directing a force applied at a point remote from the distal end of the endotracheal tube to move the distal end of the endotracheal tube sufficiently to enable the operator to point the distal end of the endotracheal tube into the nasopharynx as the endotracheal tube advances therethrough, both said fiber optic bundle and said directing means being capable of bending sufficiently to conform to the passageway formed by the nasopharynx and a channel positioned within the lumen of the endotracheal tube for delivering a local anaesthetic to the patient during the entubment procedure.

8. In a method of entubing an end tracheal tube into a patient's trachea through the patient's nasopharynx in which a flexible coherent fiber optic bundle is used to view the passageway formed by the nasopharynx during the entubment procedure wherein the improvement comprises

utilizing a mechanical means to direct a force applied at a point remote from the distal end of the endotracheal tube to move the distal end of the endotracheal tube, and

navigating the endotracheal tube through the nasopharynx by moving the distal end of the endotracheal tube by applying a force with said mechanical means so that the distal end of the endotracheal tube points in the general direction of the passageway formed by the nasopharynx as the endotracheal tube advances through said passageway toward the patient's trachea.

9. The method as set forth in claim 8 including the steps of lubricating the distal end of the endotracheal tube with an anaesthetic jelly, anaesthetizing the patient's nose and throat and anaesthetizing the patient's vocal cords with a local anaesthetic after the endotracheal tube has been navigated through the nasopharynx.

10. The method as set forth in claim 9 including the step of passing the endotracheal tube through the patient's vocal cords while the vocal cords are viewed through the fiber optic bundle and after the local anaesthetic has taken effect.