Endotracheal Tubes

Abstract

Disposable endotrached tubes are provided, such tubes having an adapter portion integral with a body portion through a juncture, with a lumen of substantial constant diameter extending throughout the body portion and juncture, the lumen opening into the adapter through a region of generally nonturbulent flow. In one embodiment, the juncture portion is corrugated to provide a flexible connection at any desired angle between adapter and body portion.

Parent Case Text

This application is a continuation of application Ser. No. 624,455 filed Mar. 20, 1967, now abandoned.

Description

This invention relates to tubes adapted for insertion into the trachea of a patient, for the purpose of administering anesthetics or facilitating breathing of the patient, for example, during surgery. More specifically, the invention relates to such tubes which are constructed so that they are disposable after use, eliminating sanitation problems which exist with the prior art tubes of this nature, and which provide greater safety and adaptability than do the prior art tubes.

The trachea is the tube which connects the larynx and the bronchi in the human body. The inside of the trachea and bronchi contain secretory glands, and their mucousal layer is lined with ciliated cells which continuously carry mucous and inspired material from the lungs through the larynx, where it may be coughed up. The presence of broncho-pulmonary secretions can produce serious problems when the patient is under anesthetics.

Tubes for insertion into the trachea, commonly referred to as endotracheal tubes (or sometimes intratracheal tubes) are commonly used by the anesthesiologist in the application to the patient of an inhalation anesthetic. Such tubes are further useful in facilitating breathing of the patient while he is under anesthesia by keeping the airway open.

Prior art endotracheal tubes have been constructed generally of rubber body portions and metal fittings such as adapters and connectors. Some such tubes have been constructed of plastic instead of rubber body portions. But in either case, the tubes are relatively expensive and consequently must be reused many times by the hospital to justify the expense of the tubes. There are many problems inherent in this procedure, the foremost among which are the lack of proper sterilization of reused tubes and the wearing out of the tubes after continued use with the result that a defective tube might be inadvertently used on some occasions. A primary consideration to all hospital functions, and especially surgical procedures, is cleanliness, and indeed, sterilization. When an endotracheal tube is used on the patient, it is of course exposed throughout its length to the mucous from the trachea, mucous which carries dangerous organisms in many patients, often including infectious diseases such as tuberculosis.

When an endotracheal tube has been used, it is the customary procedure to then clean it thoroughly. But many hospitals today are badly understaffed, and it is inevitable that sometimes tubes will be reused before they have been adequately cleaned, indeed sometimes before they have been cleaned at all. It is emphasized that the cleaning and sterilization process for such rubber and plastic tubes is very difficult, and it is further difficult to ascertain exactly when sufficient cleaning has been accomplished. Although reported instances of communication of infectious disease in this manner may be relatively rare, it is very serious when it does happen. And with the increasing use of endotracheal tubes, whereby there are many thousands of such tubes used in just the United States each day, a great many patients are exposed to infections and are indeed contaminated in this manner.

Many other problems are inherent in the prior art endotracheal tubes. One such problem is that with the rubber tubes and some of the plastic tubes of the prior art, bending of the tube has at times caused constriction of the lumen or passageway to completely terminate flow through the tube. When this occurs, there is of course the possibility that the oxygen supply to the patient will be interrupted causing the patient to die of asphyxia. This difficulty is often due to weakness of the tube from continued use, and is eliminated by use of the present invention.

A further problem concerns the frictional resistance offered by the tube in the trachea. Because many of the prior art tubes are difficult to readily move through the trachea because of the friction of the side of the tube against the interior wall of the trachea, water soluble jelly is customarily used on the exterior of the tubes to insure lubricity. But the water soluble jelly itself is not only a potential source of contaminants but may also on occasion collect inside the lumen, thus partially or completely occluding up the tube. Partial occlusion is extremely dangerous in that it may cause gradual asphyxia, often resulting in irreparable cell damage to the patient before the occlusion is noticed by the attendant.

Yet a further problem with the prior art devices is that in these devices an area of turbulence generally exists at the point where the body of the tube is joined to the separate connector or adapter. It will be recognized that turbulence of flow is most undesirable in these contexts of use wherein it is essential that the patient receive the correct dosages of anesthetic in the correct proportion of oxygen, for example, and that he receive it in a continuous and uniform manner. This area of turbulence is eliminated by use of the present invention.

Another problem with prior art endotracheal tubes which are constructed with separate joining fittings, is that on some occasions hospital personnel have insufficiently joined the fitting to the tube, resulting in separation of the tube from the fitting during use, thus shutting off the patient's supply of oxygen, etc. Here again, this occurrence is relatively rare, but it is a serious thing when it does happen, and this hazard is eliminated by use to the present invention.

Still another difficulty with the prior art tubes has been with the inflatable cuffs which are commonly used on such tubes to seal the annulus between endotracheal tube and trachea upon inflation. These cuffs are made of rather thin rubber or plastic (much like a balloon), and this material tends to wear out rather quickly. The result is that the cuffs are often damaged--sometimes unknowingly--and this damage results in an inadequate seal when the tube is used again. This deficiency is also eliminated by use of the present invention.

Among the other more important disadvantages existing in the prior art, are that prior art tubes are generally nonadaptable to varying uses and constructions, and are relatively expensive to manufacture. These disadvantages, which strike at the heart of practical application of any product, are eliminated by use of the instant invention.

In order that the present invention may be understood in detail, several specific embodiments thereof are illustrated in the accompanying drawings, wherein:

FIG. 1 is a pictorial view of one embodiment of an endotracheal tube constructed in accordance with this invention;

FIG. 2 is a pictorial view of an endotracheal tube constructed in accordance with another embodiment of this invention;

FIG. 3 is a pictorial view of an endotracheal tube constructed in accordance with yet another embodiment of this invention;

FIG. 4 is a pictorial view of an endotracheal tube constructed in accordance with still another embodiment of this invention;

FIG. 5 is a pictorial view of the adapter end of endotracheal tubes constructed in accordance with embodiments of this invention, and specifically illustrates the adapter end of the FIG. 6 embodiment;

FIG. 6 is a longitudinal cross-sectional view of an endotracheal tube constructed in accordance with one embodiment of the invention; and,

FIG. 7 is a pictorial view of an endotracheal tube of this invention in a disposable package, comprising a novel disposable article of commerce in accordance with this invention.

Referring now to the drawings in greater detail, there is seen in FIG. 1 a unitary endotracheal tube 10 constructed in accordance with one embodiment of the invention. This unitary tube 10 is constructed of a medically approved synthetic polymeric material such as nontoxic polyvinyl chloride or polypropylene. The tube 10 comprises a relatively long body portion 11 which is preferably gently curved so as to conform to the patient's anatomy, in a manner such as illustrated in FIG. 1, and a neck 12 terminating in an adapter 13 or other suitable fitting which is located on the side of neck 12 opposite the body portion 11. The curve of the tube is such that it fits firmly in the trachea without forcing any part of the trachea out of position. The adapter, connector, or other fitting is such that it will conveniently fit onto a piece of auxiliary equipment, for example the outlet or nozzle of a source of oxygen or anesthetic. It is desirably tapered gently from a first diameter adjacent neck 12 to a slightly smaller diameter adjacent the opening 15.

A passageway or lumen 17 extends through the tube, opening at the adapter in an opening 15 and at the opposite end in a beveled opening 16 which is of a size significantly larger that the diameter of lumen 17. Lumen 17 is free of constriction, and the diameter of the lumen is constant throughout body portion 11. The bevel at opening 16 in this instance is about 45.degree., and this bevel angle has been found to be very important to proper operation of the tube in many instances, in order that the proper fit at the lower end of the trachea is assured. A bevel of about 30.degree. has been found desirable for certain nasal tubes.

An inflatable cuff 18 is positioned around the tube near the lower end thereof. The purpose of this cuff is to assure, upon inflation thereof, a seal between trachea and outer wall of the tube 10, so that unwanted fluid may not be passed up the annulus between trachea and tube wall, and that all flow must be through the lumen 17 of the endotracheal tube. The cuff 18 is constructed, in accordance with this invention, of a thin layer of plastic material which circumscribes the tube 10. When the cuff 18 is in its deflated position, it assumes the same diameter, approximately, as the remainder of the tube 10. In this manner, the tube 10 has no enlarged portion for presenting difficulty as the tube is introduced into the trachea. When the cuff 18 is inflated, on the other hand, it presents a balloonlike surface which is greatly larger in diameter than the mean diameter of the tube 10.

Inflation of the cuff 18 is accomplished by means of an inflating passageway 19 which may be conveniently connected to any suitable source of air or other fluid for inflation of the cuff. An indicating bulb 20 is conveniently placed at an intermediate position along the inflating passageway 19.

It is noted that in the FIG. 1 embodiment, the neck 12 makes an angle of about 90.degree. with the body 11 of the tube, at the juncture 14. This is a particular type of tube which has been found to be of special utility in many circumstances wherein endotracheal tubes are employed.

FIG. 2 illustrates an endotracheal tube 30 in accordance with another embodiment of the invention. The tube 30 comprises generally a body portion 31, which is joined at juncture 34 to a neck 32 which is, in turn, connected to a suitable fitting such as the adapter 33. Lumen or passageway 37 extends through the tube 30, communicating to the exterior of the tube through opening 35 in the adapter and beveled opening 36 in the end of the body 31 of the tube. Here again, the desired angle of bevel is found to be about 45.degree..

The tube 30 also includes an inflatable cuff 38, which is inflated by means of an inflating passageway 39 in which is located an indicating bulb 40. The inflating passageway may be disposed a certain distance within the wall of the tube 30, or alternatively it may protrude on the exterior of the wall of the tube. Of course, if it protrudes, it is understood that this will present an enlargement of the tube diameter which may in some instances present difficulty in passing the tube into the trachea.

In the FIG. 2 embodiment, the neck 32 is joined to the body portion 31 of the tube at an angle of about 45.degree., this arrangement having been found to give good results in many contexts of use for endotracheal tubes. Otherwise, it is noted that the FIG. 2 embodiment is similar to the embodiment of FIG. 1.

It is further noted at this point that the reverse angle may be provided for either the FIG. 1 or FIG. 2 embodiment. That is, for some uses, the reverse 90.degree., or reverse 45.degree., angle of junction of the neck and body may be desirable.

The FIG. 3 embodiment is one which illustrates a tube 50 constructed with an overall curve similar to that of the FIGS. 1 and 2 embodiments, and also constructed of a synthetic polymeric material as are the tubes of FIGS. 1 and 2. The neck 52 joining with adapter 53 on the side of the neck opposite the body portion, is connected to the body portion 51 by means of a corrugated juncture 54. This juncture 54 is constructed of the same material as is the remainder of the tube 50, and being corrugated the upper portion of the tube is freely bent away from the body of the tube in any direction without constricting the lumen 57 which passes through the tube. That is, the neck 52 may join the body 51 at any desired angle. This construction has been found particularly useful in those operations in which the patient must assume an abnormal position, such as brain surgery.

The lumen 57 of tube 50 opens at one end through the opening 55 in the adapter and at the other end of the tube through the opening 56 in the body of the tube. As in the FIGS. 1 and 2 embodiments, a cuff 58 is included around the lower part of the body of the tube, this cuff being inflatable by means of an inflating passageway 59 in which may be located an indicator bulb 60.

An endotracheal tube suitable for use in an infant is illustrated in FIG. 4. This tube 70 comprises a body portion 71 which has a cross-sectional area generally smaller than the cross-sectional area of the tubes illustrated in the foregoing embodiments. For example, whereas the tubes in the FIGS. 1--3 embodiments may generally be constructed with a lumen diameter of between 2 1/2 (without cuff) or 3 1/2 (with cuff) mm. to 10mm., the lumen diameter in the FIG. 4 embodiment will generally be on the order of 2--5 mm.

The ball-shaped adapter 73 is convenient for use with certain medical equipment and is suitable for connection into a T- or Y- connector. The adapter 73 is joined to body 71 through a neck 72 and juncture 74, which in this embodiment has a curvature of 90.degree.. Lumen 77 runs through the tube, exiting at the end opposite adapter 73 through the beveled opening 76.

In FIG. 5 a particularly advantageous feature of the invention is illustrated. In prior art tubes where separate adapters must necessarily be joined to endotracheal tube bodies, there has existed a turbulence of flow at the point where the two meet. This turbulence is caused by the irregularity in lumen diameter between the tube (small diameter) and the adapter (large diameter). Such turbulence is undesirable and, moreover, can be quite critical.

The present invention as illustrated in the FIG. 5 embodiment eliminates this turbulence problem by providing for a smooth and gradual transformation from the smaller diameter tube body into the larger diameter adapter. This is clear from reference to FIG. 5, wherein it is seen that the inner wall 94 of the endotracheal tube curves on a gradual curve through the region 95 of adapter 83, between the opening 85 and the neck 82.

In FIG. 6 is seen a cross section of a tube constructed in accordance with any of the embodiments of FIGS. 1--3. Here is seen the tube 80 comprising generally body portion 81, neck 82 and adapter 83. Lumen 87 passes through the tube opening through the adapter at opening 85 and through the opposite end of the tube at beveled opening 86. A cuff of expansible material 88 is adapted to be inflated through an inflating passageway 89 in which is included an indicating bulb 90. In this embodiment it can readily be seen that the passageway from the tube 89 enters the tube wall 93 on one side of the cuff, continues in the interior of the wall 93, and terminates at the opposite end of the cuff 88. In this manner, it is seen how introduction of a fluid such as air under pressure will inflate the cuff 88 without inflating the surrounding areas of the tube 80. In this embodiment it is also seen how the thickness of wall 93 varies throughout the length of the tube, the wall thickness being greater in the body portion of the tube. The nonuniform thickness of the wall 93 in the region 95, which decreases turbulence of flow, is also noted. The lumen 87, however, is seen to be of uniform diameter throughout the length of the tube. It is apparent from FIG. 6 that the entire tube is conveniently fashioned as by extrusion from a common material and in a single piece.

FIG. 7 illustrates still another advantageous embodiment of the present invention. Here is seen a tube 100 constructed in accordance with any of the foregoing embodiments, in a disposable package 101 which may conveniently be of generally rectangular configuration as shown with a transparent top 102 of clear plastic material or the like. In this manner the surgeon or nurse may clearly see what type and style of tube is in the container, and each tube may be separately packaged in its own disposable container. The economy of this procedure is such that the tubes themselves may be disposed after use in one patient.

From the foregoing embodiments it is seen that endotracheal tubes have been provided which are unitary in construction, are feasible for disposing after one use, are much safer than the prior art tubes, and promote nonturbulent flow therethrough. These advantages are significant and of great benefit to medical science.

While the invention has been explained in terms of a number of particularly advantageous embodiments, it will be apparent to those skilled in the art that numerous changes and modifications may be made in the structure of the various embodiments without departing from the scope of the invention, which is defined by the following claims.

Claims

What I claim is:

1. A unitary disposable endotracheal tube for insertion through the mouth or nose of a patient into the trachea during a surgical operation or the like, comprising:

a gently curved body portion having a substantially constant outside diameter of a size such that said portion is adapted to fit in the trachea of the patient;

an adapter portion at the end of said tube opposite said body portion, said adapter being suitable for attaching said tube to surgical equipment, and said adapter having a maximum inside diameter approximately equal to said outer diameter of said body portion;

a juncture portion joining said body portion with said adapter portion, said juncture portion being of a length greater than said adapter portion but less than said body portion, and said juncture portion gently curving in such a manner that the end of said juncture portion adjacent said body portion is axially aligned therewith while the end of said juncture portion adjacent said adapter is axially aligned with said adapter;

a lumen of generally uniform diameter extending throughout said juncture and body portions of said tube, opening through a gently curved region of nonturbulent flow into said adapter at one end, and through a beveled opening in said body portion at the end of said tube opposite said adapter,

the diameter of said lumen throughout said juncture and said body portion being not greatly smaller than said maximum diameter of said adapter;

said body portion, said juncture and said adapter being constructed as an integral unit of a suitable synthetic polymeric material.

2. A unitary disposable endotracheal tube for insertion through the mouth or nose of a patient into the trachea during a surgical operation of the like, comprising:

a gently curved body portion having a substantially constant outside diameter of a size such that said portion is adapted to fit in the trachea of the patient; an adapter portion at the end of said tube opposite said body portion, said adapter being suitable for attaching said tube to surgical equipment, and said adapter having a maximum inside diameter approximately equal to said diameter of said body portion;

a juncture portion joining said body portion with said adapter portion, said juncture portion being of a length greater than said adapter portion but less than said body portion;

said juncture portion being corrugated to provide a flexible connection at any desired angle between said adapter and said body portion, the outside diameter of said corrugated portion being not significantly greater than the outside diameter of either said body portion or said adapter,

a lumen of generally uniform diameter extending throughout said juncture and body portions of said tube, opening through a gently curved region of nonturbulent flow into said adapter at one end, and through a beveled opening in said body portion at the end of said tube opposite said adapter,

the diameter of said lumen throughout said juncture and said body portion being not greatly smaller than said maximum diameter of said adapter;

said body portion, said juncture and said adapter being constructed as an integral unit of a suitable synthetic polymeric material.