Background of invention
Field of invention
The present invention relates to a device for endotracheal intubation.
Discussion of background information
Anatomy
The trachea is a cartilaginous and membranous tube, about 10 or 11 cm long, continued downwards from the lower part of the larynx. It is not quite cylindrical, being flattened posteriorly; its external diameter from side to side is about 2 cm in the adult male, and 1.5 cm in the adult female. In the child the trachea is smaller, more deeply placed and more movable than in the adult. In the living the lumen is smaller than in the cadaver, its diameter in the adult being about 12 mm. In the first year of life the diameter does not exceed 3 mm, while during childhood the diameters in millimeters correspond approximately with the age in years.
The shape of the trachea’s lumen in transverse section is very variable, especially in later decades. Thus it may be rounded, lunate, or flattened.
The right principal bronchus, wider, shorter and more vertical than the left, is about 2.5 cm long. Its greater width and more vertical course result in a greater frequency of foreign bodies passing into the right than into the left principal bronchus.
The left principal bronchus, narrower, and more transverse than the right, is nearly 5 cm long.
The larynx extends from the root of the tongue to the trachea. It average measurements in the European adult are as follows:
Length : male - 44 mm; female - 36 mm.
Transverse diameter : male - 43 mm; female - 41 mm.
Anteroposterior diameter : male - 36 mm; female - 26 mm.
The cavity of the larynx extends from the laryngeal inlet, by which it communicates with the larynx, to the level of the lower border of the cricoid cartilage, where it is continuous with the cavity of the trachea. It is divided into three parts by an upper and a lower pair of folds of mucous membrane which project from the sides of the cavity into its interior. The upper pair are named the vestibular folds, and the fissure between them is called the rima vestibuli. The lower pair are named the vocal cords, and the fissure between them is called the rima glottidis. The average length of the rima glottidis, in the adult male, is 23 mm; in the adult female, 17 mm. It is the narrowest part of the larynx, but its width and shape vary with the movements of the vocal cords and arytenoid cartilages during respiration and phonation.
Prior art devices
Ring ( U.S. Patent No. 3964488) described a flexible endotracheal tube having a pair of ports at the distal end of the tube as a safety measure to supply ventilation to both the right and the lefty lungs during anesthesia should the tube be accidentally advanced beyond the trachea.
Catalani (U.S. Patent No. 5146916) described an endotracheal tube with provision for delivering a drug externally of the tube through multiple holes at the distal end of the tube.
Ring’s patent as well as Catalini’s has a Murphy tip which is composed of an elongated part and a shortened part of the distal end. The elongated part of the Murphy tip while advancing through the narrowed rima glottidis may injure one of the vocal cords if the vocal cords are not fully relaxed by a muscle relaxant drug injected intravenously, or in an awake intubation or intubation without muscle relaxation.
Summary of the invention
It is one of the objects of the present invention to overcome the limitations and drawbacks of the prior art applicators for laryngeal airway, and to provide a device that considerably simplifies the procedure.
The present invention addresses the shortcomings associated with the prior art devices, and provides a solution which is straight forward.
The present invention is composed of an elongated tube approximately 34 cm long, made of plastic. The internal diameter is approximately 7.5 mm and the external diameter 10.2 mm. The tube has a concave surface on one side of its sides, as well as a convex surface at the opposite side.
The tube is flexible, elongated conduit with an expandable cuff at its distal end, starting approximately 4 cm from the distal end, and ending approximately 8 cm from the distal end.
The proximal end is connected to an adapter which enables it to be connected to an elongated tube of a respiratory machine.
The tip of the distal end is round with an opening of approximately 6 mm diameter at its apex. At the area of 4 cm from the tip to the distal border of the cuff there are two opposite round holes of approximately 6 mm diameter each.
The first pair of lateral holes starting at 1 cm from the tip, while the second pair of lateral holes starting at 2.5 cm from the tip.
The exapandable cuff’s length is of 4 cm, starting at 4 cm from the distal tip and ending at 8 cm from the distal tip.
A small tube of approximately 1 mm is attached at the outer surface of the convex side of the tube and is connected to the expandable cuff for its inflation and deflation. At its proximal end the cuff’s tube is connected to the cuff’s indicator and adapter for a syringe.
At the concave side of the tube, at the proximal end, there is a marking indicating the midline between the two pairs of lateral holes at the distal end.
The present invention includes also other tube diameters, for example, from 4 French gauge to 9 French gauge and more. The other components like the cuff and the holes are also changed accordingly.
The present invention also includes an oro-pharyngeal airway that preserves the tube from closure by the teeth, and a transparent tape that secures the tube and the oro-pharyngeal airway at the lips’ area.
The practice of the present invention is as follows :
After putting the patient asleep by general anesthesia with muscle relaxation a laryngoscopy is done using a laryngoscope. After the vocal cords are seen the Eldor atraumatic endotracheal tube is inserted through the vocal cords and into the larynx and the trachea.
Since the length of the trachea in an adult patient is approximately 10-11 cm and that of the larynx after passing the vocal cords is approximately 2 cm, it means there are approximately 12-13 cm from the vocal cords to the carina. So, if the cuff is inflated immediately after passing the vocal cords, it means there are 4-5 cm left from the endotracheal tube’s tip to the carina. However, if the tube is inserted more deeply into the trachea the cuff has to be inflated 4-5 cm from the vocal cords in order that the tube’s tip will be at the carina. However, if the tube is inserted even further into the right principal bronchus it can be even inserted into the all length of the right principal bronchus (2.5 cm) and still have the opposite proximal lateral hole ventilating the left main bronchus, since it starts at 2.5 cm from the tip.
The present invention is intended to to give a solution to two main issues regarding endotracheal intubation : a. The damage to the vocal cords by the Murphy tip by replacing it with a round tip. B. The possibility to ventilate the left principal bronchus even if the tube is inserted to the all length of the right principal bronchus. The marking at the proximal end of the tube helps to keep the two pairs of lateral holes at the anatomic position of the right and left principal bronchus.
Detailed description of the preferred embodiments
The particulars shown herein are by way of example and for purposes of illustrative discussion of the preferred embodiments of the present invention only and are presented in the cause of providing what is believed to be the most useful and readily understood description of the principles and conceptual aspects of the invention. In this regard, no attempt is made to show structural details of the invention in more detail than is necessary for the fundamental understanding of the invention, the description taken with the drawings making apparent to those skilled in the art how the several forms of the invention may be embodied in practice.
Fig. 1 shows the tip of the present invention (Eldor atraumatic endotracheal tube) : The round distal end 1, with its opening 6; the one side lateral holes 2, and the opposite side lateral holes 3, and the cuff 5.
Fig. 2 shows the present invention (Eldor atraumatic endotracheal tube) : The round distal end 1, with its opening 4; the one side lateral holes 2, and the opposite side lateral holes 3, and the cuff 5, the cuff’s tube 6 with its pilot balloon 7, and a syringe adapter; the markings at each 1 cm of the tube 8, the mark 9 at the proximal end of the tube which indicates the midline between the two opposite pairs of lateral holes ( 2 and 3); the proximal end 10, and the adapter 11 to the respiratory machine tubing.
According to the present invention (but not limited to these lengths) the opening 1 as well as the lateral holes (2 and 3) have a diameter of 6 mm.
The distance between the distal end 1 and the start of the cuff 5 is 4 cm. The length of the cuff 5 is 4 cm.
The distance from the tip 1 to the start of the first opposite pair of the lateral holes is 1 cm. The distance from the tip 1 to the start of the second opposite pair of the lateral holes is 2.5 cm.
The marking 9 at the proximal end 10 indicates the midline between the two opposite pairs of the lateral holes (2 and 3).
There are markings 8 every 1 cm of the tube for the exact knowledge about how much the tube should be inserted into the trachea to avoid misplacement.
The approximate lips-trachea distance should be measured, using the marks at the tube, in each patient before inserting the tube, by holding the tube along the outside mouth-neck surface of the patient.
What is not shown in Fig. 1 and 2 is the oro-pharyngeal airway as well as the transparent tape that secures the tube to the lips, as well as the elongated tubing connecting the Eldor atraumatic endotracheal tube to the respiratory machine, and the respiratory machine itself.
The area of the 5 openings at the distal end of the Eldor atraumatic endotracheal tube is greater in 14% than that of the Murphy tip of the endotracheal tube of the same internal diameter.
This configuration allows a better distribution of airflow as well as backflow through the Eldor atraumatic endotracheal tube than through the usual endotracheal tube with the Murphy tip by at least 14%.
This configuration allows also a more even distribution of airflow to both lungs through its principal bronchus than the usual Murphy tip which has only an opening at the tip and the Murphy eye at the elongated part of the tip.
This configuration allows also a better backflow of carbon dioxide from both lungs through the pairs of the lateral holes than the usual Murphy tip.
It is noted that the foregoing examples have been provided merely for the purpose of explanation and are in no way to be construed as limiting of the present invention. While the invention has been described with reference to a preferred embodiment, it is understood that the words which have been used herein are words of description and illustration, rather than words of limitation. Changes may be made, with the purview of the appended claims, as presently stated and as amended, without departing from the scope and spirit of the invention in its aspects. Although the invention has been described herein with reference to particular means, materials and embodiments, the invention is not intended to be limited to the particulars disclosed herein; rather, the invention extends to all functionally equivalent structures, methods and uses, such as are within the scope of the appended claims.
