WO1998019589A1

WO1998019589A1 - Laryngoscope with a flexible blade

Info

Publication number: WO1998019589A1
Application number: PCT/GR1997/000038
Authority: WO
Inventors: Spyros Mentzelopoulos; Constantinos Balas
Original assignee: Spyros Mentzelopoulos; Constantinos Balas
Priority date: 1996-11-07
Filing date: 1997-11-05
Publication date: 1998-05-14
Also published as: EP0944346B1; DE69707499D1; DE69707499T2; US6251069B1; ATE206896T1; GR1002809B; EP0944346A1

Abstract

This invention relates to a laryngoscope with a flexible blade (2) which carries two inflatable balloons (4) at the distal quarter of its concave surface. The distal two thirds of the blade are connected to its proximal part through a joint, which when operated, can cause a change of the initial contour of the blade in more than two different directions. Each balloon is connected to the handle (1) through one lumen (5a, 5b) of each thin double lumen tube (5). The two double lumen tubes extend longitudinally along the right and left edges of the blade's concave surface. A third single lumen tube (5c) is located inbetween the two former tubes. The tips of the three tubes extend 1-2 millimeters distally to the tip (17) of the blade. Operable means for the joint and the balloons are provided at the handle of the laryngoscope.

Description

LARYNGOSCOPE WITH A FLEXIBLE BLADE

This invention generally relates to examining or viewing devices and techniques used in the management of the upper airway.

a) BRIEF DESCRIPTION OF THE PRIOR ART:

Endotraeheal intubation is a medical procedure, that secures a patient's airway through placement of a tube in the patient's trachea in order to facilitate either spontaneous or controlled gas exchange.

Endotraeheal intubation is routinely carried out in operating rooms after induction of anesthesia or in emergencies, and is usually achieved without great difficulty under direct vision provided by a laryngoscope.

The laryngoscope is a medical instrument used to expose the patient's vocal cords which narrow the uppermost end the trachea i.e. the larynx.

Direct laryngoscopy is usually performed with a laryngoscope having rigid straight blade (known as a Miller type blade), or a rigid curved blade (known as a

Macintosh type blade). The most commonly used technique consists of the following steps: (i) Flexion of the patient's neck and extension of his (or hers) head in order to achieve alignment of the oral, pharyngeal and laryngeal axes.

(ϋ) Opening of the patient's mouth and introduction of the rigid blade into the right side of the oropharynx with care to avoid the teeth.

(Hi) Displacement of the tongue to the left and up into the foor of the pharynx by the blade's flange.

(iv) Insertion of the tip of the blade into the valleculla.

(v) Elevation of the handle up and away from the patient In a plane perpendicular to his (or hers) mandible and exposure of the vocal cords. (vi) Insertion of the endotraeheal tube through the exposed vocal cords. -^**

However it is sometimes impossible to visualize the larynx by using the "traditional" direct laryngoscopy even in a patient with no (or very subtile) physical signs of difficult upper airway management. 5 Conditions associated with a difficult endotraeheal intubation include obesity, trauma (laryngeal fracture, mandibular or maxillary fracture, inhalation burn, cervical spine injury, temporomandibular joint dislocation), inadequate neck extension (rheumatoid arthritis, ankylosing spondylitis, halo traction), anatomic variations (micrognathia, prognathism, large tongue, arched palate, short neck.

'0 prominent upper incisors), presence of a foreign body in the upper airway. congenital anomalies (Pierre-Robin's syndrome, Treacher Collin's syndrome, laryngeal atresia, Goldenhar's syndrome, craniofacial dysostosis), infections (submandibular abscess, peritonsilar abscess, epiglottitis) and tumors (cystic hygroma, hemangioma, hematoma).

'5 Patients with a potentially difficult intubation are frequently intubated awake and through the nose blindly or via fiberoptic endoscopy in order to maintain the protective reflexes against aspiration until the upper airway is secured. The fiberoptic bronchoscope is a tubular instrument which utilizes flexible fiberoptic bundles to transmit light and visual images during examination of the 0 upper and lower airways. It also contains one longitudinal channel extending from the rearward end to the tip through which oxygen can be insufflated and suction can be applied, and a lever at the proximal end to manoeuvre its tip. There are several instruments and alternative techniques used in order to facillitate the management of the difficult airway. 5 Some of the instruments that can be used for laryngoscopy and endotraeheal intubation are disclosed by the following patents: Phillips, U S Pat No 3 856 001 discloses a rigid laryngoscope blade wTth a straight and a curved portion containing a longitudinal channel which forms an endotraeheal tube passage A light source is secured on one side of the blade (at the forward end of the straight portion) and aimed inwardly and downwardly The light source is connected via electrical wires to a power source located in the handle Bullard, U S Pat No 4 086 919 discloses a rigid fiberoptic laryngoscope having a curved blade with a proximal connection member for connection to a laryngoscope handle and an eyepiece extending outwardly from the blade s proximal end Fiberoptic bundles extend along the longitudinal axis of the blade up to the blade's distal end An endotraeheal tube can be passed alongside the fiberoptic bundle into the larynx and trachea Lowell, U S Pat No 4 306 547 discloses a rigid fiberoptic laryngoscope with a forwardly extended blade and a tube supporting channel Fiberoptic bundles extend longitudinally along the top wall and terminate at the distal end of the channel These bundles are proximally connected to a light source and a viewing assembly Fletcher, U S Pat No 4 329 983 discloses a guide instrument for endotraeheal tubes which consists of a flexible bar that is inserted into the endotraeheal tube and a flexible line extending along the bar which can be manipulated to flex the bar in a "bowed fashion" against the endotraeheal tube so that the tube can be urged forwardly toward the trachea and away from the esophagus This device can be used along with direct laryngoscopy in order to intubate an anteriorly located larynx Roberts, U S Patent No 4 384 570 discloses a rigid laryngoscope comprising an elongated blade shaped to fit into the oral pharynx of a patient and a handle consisting of a rigid section attached to one end of the blade, a movable section attached to the handle's rigid section and adapted to pivot about~an axis-being both substantially perpendicular to the length of the rigid handle section and extending in substantially the same direction as the length of the blade and means for locking the movable handle section during laryngoscopy. The use of this laryngoscope may decrease the risk of upper airway trauma when compared with the traditional laryngoscopic technique

6. Baumann, U.S.Pat. No 4.573.451 discloses a rigid laryngoscope blade with a bendable tip which can be actuated by operable means preferably located at the proximal end of the blade. This blade can be suitable to patients in which the traditional laryngoscopic procedures do not adequately expose the patient's larynx.

7. Frankel, U.S. Pat. No 4.793.327 discloses a blind intubation instrument, which has an airway opening device, which is inserted into the patient's mouth and adjusted to a fixed position to hold the mouth open while an automated intubation guide is inserted for guiding an endotraeheal tube into the trachea.

The guide is fed into the mouth through an opening of the airway opening device, through which an endotraeheal tube is fed into the mouth as well. The guide also has an adaptor or track which allows blind manipulation of the distral part of the endotraeheal tube in order to achieve its insertion into the trachea, after which the guide is withdrawn and the airway opening device removed from the mouth.

8. Wu, U.S. Pat. No 4.982.729 discloses a rigid fiberoptic laryngoscope having an integral handle and a curved blade with fiberoptic bundles extending longitudinally along the blade and terminating at its tip A releasably attachable (to the blade) bivalve element forms a passage for threading an endotraeheal tube through the distal part of the blade. 9. Choi, U.S. Pat. No 5.003.962 diocioses an improved double^' angle blade or spatula which has three segments lengthwise. The proximal end of the blade is coupled so that it extends outward "L-fashion" from the end of the handle. The blade is then bent inwardly through a first and second bend toward the principal

5 axis of the handle forming two acute angles of 20 and 30 degrees at the first and second bend respectively. The first bend is formed on the blade at about halfway between its proximal end and its tip and the second bend is formed at the distal third of the distal half of the blade. The principal object of this modified blade is to improve the difficult airway management.

'0 10. Mac Allister, U.S. Pat. No 5.016.614 discloses an endotraeheal intubation instrument with a handle and a mechanism for retaining an endotraeheal tube on an elongated obturator element extending from the handle and releasing the endotraeheal tube therefrom. The obturator device includes an endoscope which permits visualization.

^'5 11. Parker, U.S. Pat. No 5.038.766 discloses a disposable one-piece, contoured guide element with a channel which is releasably mounted at the end of a curved blade and handle. The device is used for blindly guiding and aiming orolaryngeal and oroesophageal tubular members.

12. Augustine, U.S. Pat. No 5.203.320 discloses a rigid contoured fiberoptic 0 tracheal intubation guide having a through bore for holding an endotraeheal tube. Correct positioning of the device is detected by external palpatation of the neck of the patient and tracheal intubation is confirmed with fiberoptic visualization.

13. Flam and Gilbert, U.S.Pat. No 5.431.152 discloses an oral fiberoptic intubating 5 apparatus and method. This instrument has an elongate curvilinear blade member releasably attachable to a handle and a central channel sized to removably receive and slidably engage an endotraeheal tube therein, an elongate tubular housing removably connected at its forward end to^* the rearward end of the endotraeheal tube which removably receives a fiberoptic scope having an eyepiece at a rearward end and a fiberoptic bundle extending forwardly within the endotraeheal tube, and an adjustable positioning element through which the forwardly extending fiberoptic bundle passes for adjustably positioning and maintaining the tip end of the fiberoptic bundle relative to the forward end of the endotraeheal tube The apparatus is placed in the mouth the larynx is identified and the endotraeheal tube housing and fiberoptic scope are advanced as a unit into the trachea as the blade is removed Then the fiberoptic scope and housing are withdrawn leaving the endotraeheal tube in the desired part of the trachea Some important objects of the fiberoptic intubating apparatus and method are the improvement of the difficult airway management, the minimization of the risk of airway trauma during the procedure of endotraeheal intubation, the minimization of head and neck manipulation during laryngoscopy and intubation the elimination of the need for stylets, forceps or other rigid instruments the ability of continuous manipulation of the endotraeheal tube in an unchanged fixed position within the field of view and subsequent confirmation of placement of the tube in the desired part of the trachea, the achievement of a continuously illuminated field of view throughout the process of endotraeheal intubation the achievement of continuous protection of the field of view from obstruction by soft tissues, secretions or blood throughout the whole process of endotraeheal intubation and the achievement of oxygen insufflation, suction application, and minimization of the risk of lethal aspiration during laryngoscopy and intubation 14 Additional equipment and devices used for the management of a difficult airway includes (but is not limited to) endotraeheal tube guides e g semirigid stylets with or without a hollow core for jet ventilation, light wands, forceps designed to manipulate the distal portion of the tube etc , devices suitable for emergency nonsurgical intubation e g the transtracheal jet ventilator, a hollow jet ventilation stylet, the laryngeal mask airway, the esophageal tracheal combitube etc , cπcothyrotomy equipment and the exhaled C02 detector The andvantages and disadvantages of the laryngeal mask airway when compared to the traditional technique of endotraeheal intubation with the use of the standard Macintosh type or Miller type blades may be of particular interest Advantages Disadvantages

1 Less invasive 1 Risk of gastrointestinal aspiration Less anesthetic depth required 2 Prone or jacknrfe positions

3 Useful in difficult intubations 3 Unsafe in morbidly obese Less tooth and laryngeal trauma 4 Limits maximum positive pressure

5 Less laryngospasm and bronchospasm ventilation

6 Muscle relaxation not required 5 Less secure airway

7 Neck motility not required 6 Greater risk of gas leak and pollution

8 Less elevation of intraocular pressure 7 Causes gastric distention

9 Less risk of esophageal or endobroncial intubation

10 It is an effective alternative technique of ventilating a patient with a difficult airway in an emergency situation

The esophageal tracheal combitube provides a better seal and better airway protection against gastric aspiration than the laryngeal mask However it is available only in one disposable adult size (age > 15 years, height > 155 cm) and is quite expensive Its side perforations prevent its use as a guide for flexible fiberoptic bronchoscopy or intubation with a standard endotraeheal tube Its use is contraindicated in patients with an intact gag reflex, esoptiageal pathology, or a history of caustic substance ingestion

5 From the great variety of alternative airway management techniques and methods reference should be made to the following techniques (i) The blind nasotracheal intubation This technique has less prominent pathophysiologic effects (rigid laryngoscopy is avoided), but carries a higher risk of unintentional esophageal intubation and requires additional skill and experience as well (ιι)The "awake intubation" The pathophysiologic consequences of this technique can be more prominent because the patient's upper airway reflexes are totally or partially preserved The administration of drugs such as lidocaine may attanuate the physiologic responses to airway instrumentation (in) Thracheal intubation with the aid of a fiberoptic bronchoscope (iv) Retrograde intubation techniques

16 Lastly the composition of algorithms such as the A S A difficult ariway algorithm" provides useful guidelines for the selective or combined use of the various airway management techniques

COMMENTS ON THE PRIOR ART

a) General comments

Despite the great variety of airway management devices, techniques and methods there are still significant unsolved problems including the possibility of airway trauma, the control of the airway of patients with Cormack-Lehane grade IV laryngoscopic findings i e when it is impossible to visualize any anatomic structure of the larynx during "traditional" laryngoscopy with the Despite the great variety of airway management devices, techniques' and methods there are still significant unsolved problems including the possibility of airway trauma, the control of the airway of patients with Cormack-Lehane grade IV laryngoscopic findings i e when it is impossible to visualize any anatomic structure of the larynx during "traditional" laryngoscopy with the standard Macintosh type curved blade the pathophysiologic effects of airway instrumentation and sometimes the complexity of the technique of endotraeheal intubation which may require additional skill experience and time Particular comments (i) Blind techniques increase the risk of esophageal intubation and of airway trauma through the use of stylets or obturators and provide no visual evidence that the endotraeheal tube has entered the trachea (II) Direct laryngoscopy frequently requires head and neck positioning that may be either contraindicated or injurious to a patient with neck or head trauma There is also a risk of inability to visualize any part of the larynx (Cormack-

Lehane grade IV) and furthermore a risk of inability to intubate the trachea even if the larynx is identified Also there is usually no means for oxygen insufflation or continuous suction application throughout the procedure of endotraeheal intubation Lastly the use of any rigid blade (including the blade of the "levering laryngoscope" of Mccoy-Mirakhur) carries the risk of traumatizing the teeth, and any soft tissue (e g tongue, epiglottis) on which mechanical stress is exerted by the blade (in) With rigid fiberoptic laryngoscopy the following disadvantages are still present (a) It may be difficult to intubate the trachea without rigid stylets or other guides which may damage the soft tissues of the upper airway (b) There is a risk of obstruction of the light source or field of view lry the tube itself, blood, secretions or soft tissues.

(c) It may be impossible to confirm final tube position in the trachea.

(iv) With independent endoscope techniques such as the use of malleable 5 fiberoptic stylets and flexible fiberoptic bronchoscopy it is impossible to retract tissues away from the pathway of the instrument and the endotraeheal tube over it; the field of view is not continuously protected from blood, secretions or soft tissues and there is a risk of stylet produced injury. Furthermore it is difficult or impossible to use these types of instruments with '0 just one hand.

(v) Lastly the use of the oral fiberoptic intubating apparatus and method (Flam and Gilbert U.S. Pat. No. 5.431.152) provides an alternative airway management technique applicable in both awake and unconscious patients. This technique probably facilitates difficult intubation, decreases the risk of '5 upper airway trauma, avoids manipulation of head and neck throughout the process of intubation, allows confirmation of placement of the tube in the desired part of the trachea, provides a continuously illuminated and protected field of view throughout the process of endotraeheal intubation, and allows oxygen insufflation and suction application throughout the process of 0 endotraeheal intubation.

The use of the oral fiberoptic intubating apparatus and method in airway management is related with the following problems:

(i) The need of direct manipulation of the smooth laryngeal surface of the epiglottis which comprises increased risk of both epiglottic trauma and of accentuation of 5 the physiological responses to airway inslurmentation. (ιι)The use of the fiberoptic scope requires additional skill and experience^* and furthermore the visualisation of the laryn < can only be indirect (i e through the eyepiece of the fiberoptic scope) (HI) Oxygen insufflation and suction application cannot be provided simultaneously (iv) Direct manipulation of the laryngeal surface of the epiglottis can be quite irritating in awake patients This invention relates to a new laryngoscope which is distinguished over the prior art in general by a flexible curved blade carrying two inflattable balloons two thin double lumen tubes and one thin single lumen tube operable means for insufflation of air into the ballons through the two thin double lumen tubes and for the change of the blade's contour as well at e preferably provided at the handle of the laryngoscope The distal two thirds of the blade are connected to the proximal one third through a joint The angle between the axes of the proximal one third and distal two thirds of the blade can be varied at least between 200 - 100 degrees through operation of the joint

Furthermore the distal two thirds of the blade can move in many alternative directions (and not only in the direction of the handle) by operating the joint As a corollary the use of the joint can significantly improve the field of visualisation The flexible blade is placed in the mouth its tip is advanced either up to the valleculla or under the laryngeal surface of the epiglottis and can be used for soft tissue displacement and exposure of the glottic opening alone or in combination with one (usually the right) or both balloons The balloons (most frequently the right alone) can be used either alone or in combination with the flexible blade to expose the glottic opening The one lumen of anyone of the two thin double lumen tubes is used for the insufflation of air into the respective balloon, and the other lumen can be used either for oxygen insufflation or for suction application As a corollary suction application and oxygen insufflation can be simultaneous throughout the procedure of laryngoscopy and intubation

The thin single lumen tube which lies betw een the two thin double lumen tubes has the following characteristics (i) Its rearward (proximal end) is located cm the proximal quarter of the blade s concave surface and its tip extends only 1-2 mm distally to the tip of the blade

(n) It is made of suitable material in order o be compliant enough so that a thin bundle of optic fibers can be passeα through it This additional ability of

'flexible" fiberoptic laryngoscopy eliminates the need of head and neck manipulation throughout the process of endotraeheal intubation

REFERENCES

1 E Askitopoulou Basic principles of Anes thesiology Irakhon Crete 1990

2 G E Morgan - M S Mikhail Clinical Anes hesiology - 2nd edition 1996 3 J B West Respiratory physiology - the essentials - 5th edition QP 121 N48 1995

4 T E Oh Intensive care manual - 4th edit on

5 John Bullock, Joseph Boyle Michael B Wang NMS physiology - 3rd edition

6 Gary H Flam Susan W Gilbert document of U S patent No 5 431 152 7 Jay J Choi document of U S patent No 5 003 962

8 Jack Bauman document of U S patent No 4 573 451

9 James T Roberts document of U S patsnt No 4 384 570

BRIEF DESCRIPTION OF THE INVENTION It is therefore an object of the present invention to provide a new laryngoscope with a flexible blade, two inflattable balloons two thin double lumen tubes and one thin single lumen tube, which can be used to facilitate rapid, successful and non lethal oral endotraeheal intubation of both unconscious and awake patients. It is another object of this invention to provide a new laryngoscope and new laryngoscopic techniques which reduce the risk of upper airway trauma throughout the process of endotraeheal intubation.

Another object of this invention is to provide a new alternative "flexible" fiberoptic laryngoscopic technique which allows minimal mouth opening and minimal manipulation of the head and neck throughout the process of endotraeheal intubation. Another object of this invention is to provide new techniques of exposure of the glottic opening through balloon inflation in order to: (i) facilitate difficult airway management

(ii) decrease the risk of traumatizing the epiglottis, especially in patients with difficult intubation. (iii) attenuate the physiological responses to airway instrumentation.

Another object of this invention is to provide a new laryngoscope with a flexible blade which can be used alone or in combination with one or two inflattable balloons to expose the glottic opening without any movement of the handle and without any head and neck manipulation. Another object of the invention is to provide a new laryngoscope which allows simultaneous oxygen insufflation and suction application throughout the process of endotraeheal intubation.

Other objects of the invention will become apparent from time to time throughout the specification and claims as hereinafter related. The above noted objects and other objects of the invention are accomplished by a laryngoscope with a flexible blade which has a joint incorporated at the distal end of its proximal one third. This joint when operated allows increase or decrease of the angulation of the blade's distal two thirds in relation to its proximal one-third

The change in the angulation of the blade s distal two thirds can take place in many alternative directions and not only in the direction of the handle

The flexible blade also carries two thin double lumen tubes and one thin single lumen tube The two thin double lumen tubes are placed on the right and left edge of the blade and extend longitudinally from the proximal to the distal end of the blade The one lumen of each double lumen tube is used to inflate a respective balloon which is incorporated at the distal quarter of each thin double lumen tube

The proximal part of the connected to the balloon one lumen of each thin double lumen tube extends into the handle and terminates at a mechanism of air insufflation control which is incorporated at the proximal part of the handle so that the corresponding to it control knob of air insufflation is located close to the index finger of an operator who grasps the handle in order to perform laryngoscopy The other lumen of each thin double lumen tube has a 'ree proximal part and end which exends proximally to the proximal end of the blade and can be placed in a short tubular housing located at the distal part of the handle 2-3 centimeters above the part of the handle to which the proximal part of the blade is removably attached The thin single lumen tube is placed on the blade s concave surface inbetween the two thin double lumen tubes and extends longitudinally from the tip of the blade up to its proximal quarter This compliant and transparent tube can house a thin fiberoptic bundle which can be inserted through its proximal end and advanced through its distal end under the laryngeal surface of the epiglottis, to facilitate both identification of the glottic opening and manoeuveπng of the tip of an endotraeheal tube in order to achieve suc cesful insertion of the tube into the trachea The use of the fiberoptic bundle offers independent additional indirect visualization of the area of interest i e the glottic opening and of the relative position of the endotraeheal tube's tip during the most critical part of the process of endotraeheal intubation i.e. during the insertion attempt of the tip 15T the endotraeheal tube in the glottic opening. As a corollary more accurate and less traumatic manoeuvering of the tip of the endotraeheal tube is achieved especially patients with difficult airways. Lastly the fiberoptic bundle can be used to confirm correct tube placement in the trachea.

The tips of the two thin double lumen tubes and of the thin single lumen tube extend only 1-2 millimeters distally to the flex ible blade's tip.

DESCRIPTION OF THE DRAWINGS

FIG. 1. is a profile of the new laryngoscope showing the handle (1), blade (2). light source (3), location of a deflated balloon (4), a thin double lumen tube (5). the connection points (6) between the proximal ends of each lumen of the thin double lumen tube and their respective tubular extensions (7) in the handle and in the tubular housing of the handle (8), the mechanism of insufflation of air (9) into a balloon and the approximate location of its respective control knob (10). the rearward end (11) of the extension of the second lumen of a thin double lumen tube (where either oxygen insufflation or suction application can take place), the location of the joint (12) and its respective control lever (13). The first inset (14) shows the principle of the mechanism of air insufflation into a balloon and the second inset (15) shows the tubular housing (8) of the handle and the connection points between the proximal ends of the two tubes of a thin double lumen tube and the distal ends of their respective tubular extensions at the handle. The third inset (16) shows a frontal aspect of the proximal part of the handle with the two control knobs for air insufflation into the flexible blade's balloons. 17 = tip of the flexible blade. 18 = thin single lumen tubular extension for oxygen insufflation or suction application. FIG 2 Is a profile of the new laryngoscope showing the location of the joint (1) and some details of its preferable respective control mechanism For simplicity and more effective description the thin single lumen tube, the thin double lumen tubes, balloons, mechanisms of air insufflation and respective control knobs are

5 omitted 1 = Joint, 2 = Control lever 3 = Plate incorporated in the distal two thirds of the blade, 4 = first inset showing a rearward view of the proximal part of the handle where the joint's control lever is located, 5 = second inset showing a frontal section of the handle and a preferable mechanism of the plate's (and consequently of the blade s distal two thirds) rotation 5a = plate 5b = Frontal

"0 section of the joint's control lever 5c 5d = springs contained in the handle 5c 5d = springs incorporated in the flexible blade the third inset 6 shows a preferable version of the joint, which consists of one sphere (6a), one proximal (6b) and one distal (6c) contact surface The fourth inset 7 shows the distal end of the handle in which the proximal end of the blade is removably attached and

'5 shdably engaged 7a= contact area for the conduction of electricity to the blade s light source 7c = section of the extension of the spring responsible for the increase in the blade s distal two thirds angulation 7e = section of the extension of the spring responsible for the decrease in the blade's distal two thirds angulation 0 7b 7d = sections of the extensions of the 2 springs responsible for the rotation of the blade's distal two thnds

The fifth inset 8 shows the proximal part of the blade, which is removably attached and shdably engaged in the distal part of the handle 8a = contact area for the conduction of electricity to the blade's light source, 8c = section of the 5 extension of the spring responsible for the increase in the blade's distal two thirds angulation, 8e = section of the extension of the spring responsible for the decrease in the blade's distal two thirds angulation 8b, 8d sections of the extensions of the two springs responsible for the rotation of the blade's distal two thirds

The sixth inset 9 shows one of several alternative mechanisms for firm attachment between the springs' extensions 9a = spring extension from the handle, 9b=small metallic cube with a small central tube in which the distal part of 9a can be shdably engaged, 9c = spring extension from the blade with a proximal end incorporated in 9b

FIG 3 Shows the results of the operation of the joint 1 = joint, 2 = increased angulation of the flexible blade, 3 = intermediate angulation of the flexible blade 4 = decreased angulation of the flexible blade The inset 5 shows a view from above when the distal two thirds of the blade are rotated by operating the joint 5a= joint,

5b, 5c = springs responsible for rotation, bd = leftward rotation 5e = πghtward rotation

The two thin double lumen tubes, the inflattable balloons and the one thin single lumen tube are omitted for simplicity of description The area of the joint is covered by smooth elastic material so that there are no sharp metallic protrusions

FIG 4 Shows the right thin double lumen tube (1) and the inflated right balloon (2) The more compliant pilot balloon (4) has been compressed by the corresponding control knob (3) The first inset (5) shows, a view from above 5a = right thin double lumen tube, 5b = left thin double lumen tube, 5c = thin single lumen tube 5ca = proximal end of thin single lumen tube, 5cd = distal end of thin single lumen tube, 5d = thin fiberoptic bundle The second inset (6) shows a view from above with both balloons inflated 6a = right balloon, 6b = left balloon, 6c, 6d = proximal free ends of the extensions [see FIG 1-18] of the second lumens [inset 7-7b] of the two thin double lumen tubes The third inset 7 shows a closer view of a thin double lumen tube: 7a = firsHυmen for air insufflation into the deflated balloon ( c). 7b = second lumen for continuous oxygen insufflation or suction application. ^vd = connection point. 7e = proximal free end (available for connection) of the second lumen (7b).

DESCRIPTION OF MORE THAN ONE METHODS OF OPERATION OF

THE NEW LARYNGOSCOPE

If there is no contraindication the patient's neck can be flexed and his (or hers) head can be extended in order to achieve alignment of the oral, pharyngeal and laryngeal axes just prior to laryngoscopy.

After opening the patient's mouth the flexible blade (FIG. 1-2) is inserted into the right side of the oropharynx, the tongue is displaced to the left and up into the floor of the pharynx by the flexible blade s flange and the flexible blade's tip

(FIG.1-17) is inserted into the vallecula. Now the doctor performing laryngoscopy has the following alternative laryngoscopic and intubating manoeuvres at his disposal: a) He can gradually inflate the right balloon (FIG 4-2) by applying gradually increasing pressure on the corresponding control knob (FIG. 1-10) with his left or right index finger until adequate exposure of the glottis for intubation is achieved.

The right balloon (FIG.4-2) when gradually inflated causes a smooth upward displacement of the soft tissues of the valleculla with minimal mechanical stress and a subsequent elevation of the epiglottis and frequently adequate

(for endotraeheal tube insertion) exposure of the glottic opening. b) If right balloon inflation (FIG.4-2) does not achieve the desired exposure of the glottic opening the operator can increase the angulation of the flexible blade

(FIG.3-2) by activating the joint (FIG. 2-6) through the use of the corresponding control lever (FIG.2-2) in order to cause further ^'efevationτrf the epiglottis and greater exposure of the glottis.

If the patient's larynx (and consequently the glottis) is displaced either to the left or to the right by a disease process or trauma the operator can (either before or after the increase in the angulation of the flexible blade (FIG.3-2)) rotate the distal two thirds of the blade (FIG.3-5) towards the direction of the laryngeal displacement by moving the control lever (FIG.2-2) horizontally and in the opposite direction of the laryngeal displacement with his thumb. The horizontal movement of the control lever (FIG.2-2, FIG.2-4) will activate the joint's rotation mechanism (FIG.2-5). c) If the combined balloon inflation (FIG.4-2) and joint activation (FIG. 3-2), (FIG.3-5) cannot cause sufficient exposure of the glottis the operator can still raise the handle up and away from the oatient in a plane perpendicular to the patient's mandible in order to achieve adequate glottic visualization for endotraeheal tube insertion. d) If the combination of the previous manoeuvres (a, b. c) does not provide sufficient exposure of the glottis, the ooerator (or an assistant) can insert a thin fiberoptic bundle (FIG.4-5d) through the proximal end (FIG.4-5ca) of the transparent thin single lumen tube (FIG.4-5c) and advance it through its distal end (FIG.4-5 cb), and under the laryngeal surface of the already elevated by previous right balloon inflation (FIG.4-2) epiglottis. The larynx will be identified through the eyepiece of the fiberoptic bundle and additionaly the relevant position of the flexible blade's tip to the glottic opening will be known so that any further manoeuvre (such as further change in the blade's angulation or further right balloon inflation or slight right balloon deflation or left balloon inflation (FIG.4-6b) will be more efficient in achieving adequate direct exposure of the glottis and subsequent tube insertion. If the glottis can be identified only indirectly [i.e. through the eyepiece of the thin fiberoptic bundle (FIG.4-5d)] the endotraeheal tube can be inserted into the mouth or through a nostril and advanced towards the tip of the fiberoptic bundle. The tube's tip will be succesfjlly and rapidly manoeuvred into the glottic opening as soon as it becomes^, visible through the eyepiece of the fiberoptic bundle so that its relevant position to the glottic opening will be known.

Alternatively if manipulation of head and neck are contraindicated the operator can apply the following technique: a') Decrease of the flexible blade's angulation [FIG.3-4] through operation of the joint [FIG.3-1]. b') Insertion of a thin fiberoptic bundle [FIG.4-5d] into the thin single lumen tube [FIG.4-5c] through its proximal end [FIG.4-5ca]. The tip of the thin fiberoptic bundle is advanced just proximally to the tip [FIG.4-5cb] of the thin and transparent single lumen tube [FIG.4-5c], c') The flexible blade is then inserted into the right side of the patient^'s mouth and its tip is advanced under the la-yngeal surface of the epiglottis under indirect vision through the eyepiece of the already incorporated (step b) fiberoptic bundle. d') The epiglottis is then displaced smoothly and without any risk of trauma through inflation of the right balloon [FIG.4-2]. If additional direct vision of the glottic opening is achieved the operator inserts an endotraeheal tube into the patient's trachea. e') After inflation of the balloon [FIG.4-2] the operator can increase [FIG.3-3], [FIG.3-2] the initially decreased [FIG.3-4] angulation of the flexible blade by reactivating the joint [FIG.3-1]. If adequate direct vision of the glottis is achieved, the operator intubates the patient's trachea. f) The field of direct visualization can still be extended (after^' steps a^'7^*b^' , c^' , d', e' have already been followed) by raising the handle [FIG.1-1] of the laryngoscope up and away from the patient in a plane perpendicular to his (or hers) mandible. 5 g') If the glottic opening cannot be directly identified after steps a', b', c d' e', f the operator can advance the thin fiberoptic bundle [FIG 4-5d] through the distal end [FIG 4-5cb] of the single lumen tube [FIG.4-5c], identify the glottis, insert the endotraeheal tube into the oropharynx (through the patients's mouth or t irough one of the patient's nostrils), ^"0 direct the tube's tip towards the tip of the thin fiberoptic bundle and insert the tube's tip through the glottic opening under indirect vision through the thin fiberoptic bundle's eyepiece The thin fiberoptic bundle can then be advanced along with the endotraeheal tube into the trachea to confirm correct tube placement.

'5 Additionaly the operator has the option of continuous and simultaneous suction application and oxygen insufflation through he free proximal end [FIG 1-11], [FIG 4-6c, 4-6d] of each second lumen [FIG 4-7t] of each of the two thin double lumen tubes [FIG.4-5a, 4-5b], throughout the process of laryngoscopy and intubation Additionaly the operator has the option of rc tating [FIG 3-5] the distal two thirds of 0 the flexible blade [FIG.1-2] through activation of the corresponding mechanism [FIG.2-5], [FIG.3-5b, 3-5c] by moving the lever [FIG.2-2] horizontally [FIG.2-4] with his thumb, in order to achieve better e> posure of a due to trauma, or disease process displaced glottis. BRIEF REFERENCE TO THE ADVANTAGES OF THE NEW ~~

LARYNGOSCOPE OVER THE ^αRIOR ART IN GENERAL

This new laryngoscope with a flexible blade, two inflattable balloons, two thin double lumen tubes and one thin single lumen tube offers the following important advantages

1 Facilitation of the difficult airway management

The combined use of the joint [FIG 3-1] and of the balloons [FIG 4-6a 4-6b] (the right balloon [FIG 4-2, 4-6a] is mo st frequently used alone) offers new techniques of extending the field of visualization and of exposing the glottis Consequently it will be easier to intubate patients with conditions associated with a narrow field of visualization (e g prominent upper incisors, inadequate mouth opening), or with inability of alignment of the oral pharyngeal and laryngeal axes (e g anterior larynx, ankylosing spondy tis) Furthermore in conditions associated with contraindication of head and neck manipulation (e g cervical spine injury) he visualization of the glottis can be achieved through the eyepiece of the thin fiberoptic bundle [FIG 4-5d] after the flexible blade with decreased angulation [FIG 3-4] has been placed under the laryngeal surface of the epiglottis and the inflated right balloon [FIG 4-2] has smoothly and sufficiently displaced the epiglottis in order to create a relatively wide passage for the tip of the thin fiberoptic bundle [FIG 4-5d] This latter technique greatly facilhtates airway management in traumatized patients whose otherwise frequently easy intubation c an become difficult because of the contraindication of head and neck manipulation

2 Continuous and simultaneous oxygen insufflation and suction application through the proximal ends of the two "second lumens" [FIG 4-6d, 4-6c], [FIG 4-

7b] of the two thin double lumen tubes [FIG 4-5a 4-5b] This technique decreases the risk of fatal hypoxemia during laryngoscopy and intubation and allows simultaneous removal of blood and secretions from the field of visualization As a corollary the procedure of endotraeheal intubation becomes both safer and faster Less risk of airway trauma the flex ble blade [FIG 1-2, FIG 3] provides alternative ways of extension of the field of visualization such as increased angulation [FIG 3-2] and rotation [FIG 3- 5] of its distal two thirds leverage on the upper teeth is easily avoided and the mechanical stress on the soft tissues is minimized because the change in the blade s contour through the operation of its joint [FIG 3] provides maximal exte nsion of the field of visualization with the least possible mechanical deformation of the upper airway s soft tissues which must be displaced in order to achieve glottic exposure by approximating their initial cuvarture (i e their cuvarture just prior to laryngoscopy) The displacement of the susceptible to trauma tissues of the valleculla (and the sudsequent elevation of the epiglottis) is achieved through the inflation of the balloons [FIG4-2 4-6a, 4-6b] (most frequently only the right balloon [FIG 4-6a] is inflated), which have a very smooth surface that virtually eliminates the risk of lacerations

Additionally when the flexible blade s angulation is decreased [FIG 3-4] and its tip is placed under the more suscebtible to trauma than the tissues of the valleculla laryngeal surface of the epiglot is (under indirect visualization through the eyepiece of the fiberoptic bundle [FIG 4-5d]) the direct displacement of the epiglottis through ballloon inflation [FIG 4 2, 4-6a, 4-6b] virtually guarantees its mechanical integrity Less prominent physiologic responses to airway instruentation The irritant receptors which he between airway epithelial cells and respond to noxious stimuli (including mechanical stre ss) seem to play an important role in the generation of the physiologic resporses to airway instrumentation These receptors show rapid adaptation to mechanical stimulation i e the deformation of the nerve terminal they contain is not maintained during continuous stimulus application Furthermore usually only rapidly applied (or sufficiently forcefull) stimuli such as pressure exertion by a metallic blade can generate an action potential in the contained nerve terminal and the intensity of the resulting physiologic responses (elevation of arterial, intracranial and intraocular pressure and increased heart rate) o airway instumentation is direcly proportional to the number of irritant rec 3ptors which are effectively deformed when pressed by a rigid mettalic blade The gradual and smooth soft tissue displacement by balloon inflation [FIG 4-2] decreases the individual probability of e fective deformation of each irritant receptor contained in the area of displac ed soft tissues As a corollary the effective stimulation of a smaller number }f irritant receptors will result in less intense physiologic responses This advantage can be of particular value in patients with coronary artery disease wh D cannot tolerate acute increases in myocardial oxygen consumption due to acute elevations of systolic arterial pressure and sudden increases in heart rate and in patients with head trauma who cannot tolerate further acute elevations of an already elevated intracranial pressure

Claims

' ~^"

What we claim now is:

1. A laryngoscope for tracheal intubation wh ch comprises in combination: a flexible elongated blade [FIG.1-2] compi ising in combination: (i) a joint [FIG.2-6] which allows both gradual increase [FIG.3-2] and gradual decrease [FIG.3-4] in the angulation of the distal two thirds of said blade in combination with either leftward [FIG.3-5d] or rightward [FIG.3-5e] rotation of said blade, so that the contour o' said blade can be changed in many directions, and not only in the direc tion of the handle, according to the operator's clinical decision.

(ii) a system of four springs [FIG.2-12, 2- 13, 2-5c\ 2-5d'] and a spatulated plate

[FIG.2-3, FIG.2-5a] serving in combination with the joint [FIG 2-6] as part of the mechanism responsible for the changes in said flexible blade's contour.

(iii) two thin double lumen tubes [FIG.1 -5], [FIG.4-7], [FIG.4-5a. 4-5b] each carrying an inflattable balloon at its di tal quarter [FIG.4-7c] ,

(iv) one thin single lumen tube [FIG.4-5c] placed on the concave surface of said blade inbetween the said two thin double lumen tubes. [FIG. 4-5a. FIG.4-

5b). a handle [FIG. 1-1] comprising in combination: (i) two control knobs [FIG.1-10, FIG.1-16] two pilot balloons [FIG.1-14d] and two thin single lumen tubes [FIG.1-7] as means of independent inflation [FIG.4-

2], [FIG.4-6a, 4-6b] of each said infla table balloon [FIG.4-7c].

(ii) a control lever [FIG.2-2], [FIG.1-13] and a system of four springs [FIG.2-10,

2-11, 2-5c, 2-5d] as operable means for the changes in the said flexible blade's contour. (in) two tubular housings [FIG 1-8] each of which is attached at one of the two lateral exterior sufraces of the distal one fifth of said handle, and each of which contains one thin single lumen ube [FIG 1-15] The laryngoscope of claim 1 in which sa d joint [FIG 2-6] is incorporated at the distal part of said flexible blade's proxima one third [FIG 1-12, FIG 3-1] The laryngoscope of claims 1 and 2 in v hich said the joint [FIG 2-6] does not cause any sharp protrusions to the conto JΓ of said flexible blade The laryngoscope of claim 1 in which each of said four springs which are incorporated in said flexible blade has a p roximal end [FIG 2-8a, 2-8b 2-8c 2- 8d] extending approximately 2mm proximally [FIG 2-9c] to the proximal end of said flexible blade and is incorporated into a small receptor mechanism [FIG 2- 9b] The laryngoscope of claim 1 in which said spatulated plate [FIG 2-3, FIG 2-5a] is incorporated in the distal two thirds o said flexible blade and has a shape similar to the shape of the distal two hirds of said flexible blade and one concave and one convex surface with length and width slightly smaller than the length and width of the respective conca\ e and convex surfaces of said flexible blade The laryngoscope of claims 1 4 and 5 in which said spatulated plate [FIG 2-3 FIG 2-5a] of said flexible blade has a prc ximal end located at the proximal end of the distal two thirds of said flexible blac e The laryngoscope of claims 1, 4, 5 and (• in which the two of said four springs [FIG 5c 5d'] of said flexible blade serve to the leftward and πghtward rotation [FIG 3-5d, FIG 3-5e] of the distal two thirds of said flexible blade and their distal ends are firmly attached to the proximal end of said spatulated plate [FIG 2-5a,

2-3]

8. The laryngoscope of claims 1, 4, 5 and 6 in which the one [FIG.2-12] oT said four springs of said flexible blade serves to increase the angulation [FIG.3-2] of the distal two thirds of said flexible blade and is firmly attached to the concave surface of said spatulated plate [FIG.i -3] extending up to the tip of said spatulated plate [FIG.2-3a].

9. The laryngoscope of claims 1, 4. 5 and 6 in which the one [FIG.2-13] of said four springs of said flexible blade serves to decrease the angulation of the distal two thirds of said flexible blade, and is firmly attached to the convex surface of said spatulated plate [FIG.2-3] extending up to the tip of said spatulated plate [FIG.2-3a].

10. The laryngoscope of claims 1 and 4 in which each of the distal ends [FIG. 2-7a, 2-7b, 2-7c, 2-7d] of said four springs of said handle extends approximately 2-3 mm distally to the distal surface [FIG.2-71 of said handle and is always shdably engaged into the corresponding said re ceptor mechanism [FIG.2-9b] of the corresponding said spring of said flexible blade, when the proximal end of said flexible blade [FIG.2-8] is shdably engaced in the distal end [FIG.2-7] of said handle.

11. The laryngoscope of claims 1, 7 and 10 ir which two of said four springs of said handle [FIG.2-5c, 2-5d] serve as part of the mechanism for leftward and rightward rotation [FIG.3-5d, FIG.3-5e] c f the distal two thirds of said flexible blade and their distal ends [FIG.2-7b, 2-7d] can be removably attached and slidably engaged into the proximal rec sptor mechanisms [FIG.2-9b] of the proximal ends [FIG.8b, 8d] of the corresponding said two springs [2-5c\ 2-5d'] of said flexible blade. 12. The laryngoscope of claims 1, 7 and 10 in which one [FIG.2-11] of four said springs of said handle serves as part c f the mechanism responsible for the increase in the angulation [FIG.3-2] of >aid flexible blade, and its distal end [FIG.2-7c] can be removably attached and shdably engaged into the proximal receptor mechanism [FIG.2-9b] of the corresponding said one spring [FIG.2-12] of said flexible blade.

13. The laryngoscope of claims 1, 7 and 10 in which one [FIG.2-10] of four said 5 springs of said handle serves as part of the mechanism for the decrease in the angulation [FIG.3-4] of said flexible blade , and its distal end [FIG.2-7e] can be removably attached and shdably engaged into the proximal receptor mechanism [FIG.2-9b] of the corresponding said one spring [FIG.2-13] of said flexible blade.

14. The laryngoscope of claims 1, 7, 8, 9, 1( , 11, 12 and 13 in which a lever [FIG.2- '0 2] movable in all directions [FIG.2-4] p'eferably by the operator's thumb is provided at the rearward surface of the proximal part of said handle along with means for stretching each of four said springs of said handle installed firmly within the hollow core of the proximal par of said handle.

15. The laryngoscope of claim 1 in which two said thin double lumen tubes [FIG.1- '5 5], [FIG.4-7] of said flexible blade ext end longitudinally along the concav^Ω surface of said flexible blade, each havinc) a distal end extending 1-2 mm distally to the tip [FIG.1-17] of said flexible blade.

16. The laryngoscope of claims 1 and 15 in which each said thin double lumen tube [FIG.4-7] has one lumen (called first lumen) [FIG.4-7a] serving for either oxygen 0 insufflation or suction application throughout the process of laryngoscopy and endotraeheal intubation.

17. The laryngoscope of claims 1, 15 and 16 in which each said thin double lumen tube [FIG.1-5], [FIG.4-7] of said flexible blade has two proximal free ends [FIG.4-7d, FIG.4-7e] each corresponding to one of its lumens [FIG.4-7a, FIG.4- 5 7b], and each one being available for connection with the distal end of a corresponding to it thin single lumen tube [FIG.1-7], [FIG.1-18] of said handle. The laryngoscope of claims 1, 15, 16 and 17 in which said handle contains two thin single lumen tubes [FIG 1-17] eac h extending longitudinally along the internal sufrace of each of the two late al aspects of said handle, and each having a proximal end incorporated into a pilot balloon [FIG 1-9] and a distal end [FIG 1-15b], [FIG 4-7d] available for comection with the proximal end of the corresponding to it first lumen [FIG 4-7d] of the unilateral thin double lumen tube The laryngoscope of claims 1, 15, 16 and 17 in which each said pilot balloon [FIG 1-9] is located in the proximal one th ird of said handle and is at least three times more compliant than the corresponding inflattable balloon [FIG 1-4]

[FIG 4-2] of said blade The laryngoscope of claims 1, 15, 16 . d 17 in which each said thin single lumen tube [FIG 1-15] contained in each said tubular housing [FIG 1-8] of said handle has a distal end [FIG 1-15c] available for connection with the proximal end [FIG 4-7c] of the second lumen [4 7b] of the corresponding thin double lumen tube of said handle and a distal fre e end [FIG 1-11], [FIG 4-6c FIG 4-6d] available for either oxygen insufflation or suction application The laryngoscope of claim 1 in which sεid thin single lumen tube [FIG 4-5c] of said flexible blade extends longitudinally along the medial part of the concave surface of said blade and has a distal end [FIG 4-5cd] extending 1-2 mm distally to the tip of said flexible blade, and a poximal end [FIG 4-5ca] located on the proximal quarter of said flexible blade The laryngoscope of claims 1 and 21 in which said thin single lumen tube [FIG 4-5c] of said flaxible blade has a high specific compliance which allows both easy insertion and advance of a th n fiberoptic bundle [FIG 4-5d] through its proximal end [FIG 4-5ca] and lumen respectively

23. The laryngoscope of claims 1, 21 and 22 in which said thin single lumefTtube [FIG.4-5c] of said flexible blade is made c f transparent material.

24. The laryngoscope of claims 1, 2, 3, 6, 7, 8, 9, 15 and 21 in which said thin double lumen tubes [FIG. 4-5a, 4-5b] anc said thin single lumen tube [FIG.4-5c] do not cause any limitation to the extend of clinically desired changes [FIG.3-2,

3-3, 3-4, 3-5] in said flexible blade's contour.

25. The laryngoscope of claims 1, 2, 3, 6 7, 8, 9, 15, 21 and 24 in which the corresponding to the area of said joint [F G.2-6] external structures of said thin double lumen tubes [FIG.4-5a, 4-5b] and of said thin single lumen tube [FIG.4- 5c] suitably reinforced, so that no obstruction to any lumen of any said tube of said flexible blade can be caused by any clinically desired change [FIG.3-2, 3-3, 3-4, 3-5] in said flexible blade's contour.