Transthoracic Cannula-type Device For Cardiopulmonary Resuscitation

Abstract

A medical instrument, taking the general form of a flexible catheter or cannula, combines a passage for intracardiac drugs with an electrode or electrodes for applying an electrical stimulus to the heart. Designed primarily for use in emergency cardiopulmonary resuscitation procedures instituted in cases of cardiac arrest, the instrument incorporates an expansible stop collar at its tip that stabilizes its position following its penetration of the chest and heart walls, and in particular prevents accidental withdrawal or escape thereof. The stably positioned instrument affords the opportunity for external cardiac heart massage without danger of heart damage resulting from motion of the instrument that would normally occur if an instrument of this type is not removed during said external cardiac massage of the heart muscle.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention pertains to medical instruments of the cannula or catheter type designed for transthoracic insertion into the heart muscle through a previously inserted needle, and adapted following insertion to serve as a channel for the administration of intracardiac drugs, as a means for applying an electrical stimulus to the heart, and as a means for obtaining venous blood samples for analysis.

2. Description of the Prior Art

Applicants are aware of the following patents believed pertinent to consideration of the invention:

Schipley 2,976,865 Schein et al. al. 3,078,850 Kilpatrick 3,087,486 Beebe et al 3,098,813 Chesebrough et al 3,313,293 Chardack 3,348,548 Khalil 3,359,974 Quinn 3,416,534 Ackermann 3,485,247

The prior art as represented by these patents contains at least broad teaching for the concept of applying electrical stimuli and drugs through a single instrument designed for transthoracic insertion into the heart muscle. However, the patents fail to solve a problem which becomes of particular concern in emergency resuscitative situations. The problem results from the necessity of external cardiac massage of the heart for the purpose of restarting it, while the cannula remains in inserted position.

In recent years, there has been developed in hospitals an emergency procedure designed to resuscitate a patient whose heart has failed. Sometimes called a "Code 99," this procedure involves a coded call put out over the intercommunication system, and responding immediately to this call is a highly trained team of physicians, nurses, and technicians. Wherever the members of the team may be in the hospital, they converge immediately upon the room occupied by the patient, and in a race against time, initiate cardiopulmonary resuscitation of the patient, with each member of the team carrying out his or her duties, in a combined effort that involves considerable training, drill and the use of highly sophisticated medical instruments.

One or more of the resuscitative procedures may prove successful in restarting the stopped heart of the patient or in producing normal beating of a heart that, for example, may be fibrillating or may otherwise show imminent danger of full cardiac arrest. External cardiac massage is always used, and often is sufficient to resuscitate the patient. Or, the injection of adrenalin directly into the heart may aid in the resuscitation effort. Or, the application of electrical stimuli by such apparatus as a so-called "pacemaker" may be helpful.

It is, of course, extremely critical that any or all of these resuscitative methods be applied with an absolute minimum of delay. Time is absolutely critical, and even the loss of a few seconds can result in failure to resuscitate the patient or, in some instances, serious brain damage, should the restoration of the heartbeat not be obtained within a given, very short period of time.

The difficulty which we have noted arises from the fact that heart massage cannot effectively be carried out while there remains in the chest a rigidly constituted, transthoracically inserted cannula or cardiac electrode.

This is by reason of the fact that the pressures exerted during heart massage produce motions of the heart in respect to a cannula or electrode, tending to drive instruments of this type too deeply into the heart. Or, such motions may cause the opening resulting from penetration of the heart wall by such instruments to be enlarged extensively, or the instrument may be caused to escape or come out of the right ventricle. In such an event, fluids flowing through the cannula might flow into the pericardium, the mediastinum, or the lung. Then again, the heart wall may become torn by the instrument during the application of heart massage or the instrument may be caused to alternately withdraw from and re-penetrate the heart wall, repeatedly during the heart massage.

Accordingly, instruments of this type are withdrawn before heart massage is initiated, and if reinsertion is indicated, external cardiac heart massage must be temporarily discontinued. One danger here is that the transthoracic insertion, accomplished under emergency conditions, may cause the instrument to strike a coronary artery or the like, with fatal results. Obviously, reinsertion of the instrument doubles the possibility of such an occurrence.

SUMMARY OF THE INVENTION

The present invention seeks to provide, in a single instrument, a solution to the problems described above. To this end, we provide a medical instrument which briefly may be said to consist of an elongated, flexible tube adapted to provide a conduit for the administration of intracardiac drugs or the like, or the withdrawal of blood samples, and provided at its tip with an annular, radially expandable collar. In close proximity to the collar, are axially spaced, sleeve-like electrodes. An inflating tube for the collar, and lead wires for the electrode are confined within and are angularly spaced about the wall of the flexible tubular member through which the intracardiac fluids pass into the heart. The electrodes are so spaced relative to one another, and to the stop collar, as to assure that both electrodes will impinge upon the tissues of the wall of the heart muscle when the stop collar is expanded. The stop collar, further is so located as to limit the tubular member against withdrawal in an axial direction, as well as against lateral displacement.

The instrument includes, at its outer end, a fitting adapted for effecting the rapid connection thereof to a source of intracardiac fluids to be applied. Further, in a preferred embodiment there is provided an auxiliary tube, connected in communication with the tubular member described above, said auxiliary tube being adapted to provide a conduit for intracardiac fluids or withdrawal of blood samples. In this way, the administration of a multiplicity of intracardiac fluids is included within the capability of the instrument. The main tubular member, but not the auxiliary tube, is provided with a check valve, so arranged as to prevent backflow of the administered drugs. The auxiliary tube, together with its check valve, is located in advance of the check valve of the main tube, that is, between the main tube check valve and the inserted tip of the device.

The instrument constituting the present invention is particularly designed for transthoracic insertion into the right ventricular cavity by a procedure wherein there is first inserted a spinal needle, which initially may be in communication with a syringe usable to remove a blood sample, The removal of the syringe permits insertion of the instrument constituting the present invention directly through the needle into the right ventricle, after which the needle is removed and the collar is inflated. Intracardiac drugs and/or other fluid medications may then be administered, and temporary cardiac pacing can be instituted if the situation so dictates. Further, as indicated above, the application of heart massage becomes permissible while the instrument remains inserted.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is a longitudinal sectional view on an enlarged scale, portions being broken away, of a medical instrument according to the present invention;

FIG. 2 is a transverse sectional view on line 2--2 of FIG. 1;

FIG. 3 is a pictorial view illustrating the usage of the invention, the invention being shown on a scale considerably smaller than that of FIGS. 1 and 2; and

FIGS. 4-9 are views illustrating successively following steps in the use of the invention, the dotted lines representing fragmentarily the skin and heart of the patient.

DESCRIPTION OF THE PREFERRED EMBODIMENT

The reference numeral 10 designates generally a medical instrument constructed according to the present invention. In a preferred embodiment, the instrument comprises an elongated, flexible, tubular member 12 which may be considered a main tube, formed of a plastic material desirably of constant inner and outer diameter from end to end thereof. The tubular member 12 is open at its tip 13, and at its opposite or outer end is sealably connected to a fitting 14 adapted to permit connection of the tubular member to a source of fluid drugs, medicaments, or other fluids to be directed into the heart "H" of the patient to be resuscitated, through channel 15 provided by the tubular member.

Within channel 15, at the outer inlet end 16 of the tubular member, there is mounted a check valve 17. This has been illustrated by a conventional symbol in the drawing, since the check valve can be any of various known types already in use, and does not constitute per se a part of the present invention.

At the tip end 13 of the tubular member 12, there is provided an expandable collar 18, constituting a stop or abutment disposed upon tip 13 for the purpose of stabilizing the position of the instrument following transthoracic insertion thereof into the right ventricular cavity of the heart.

The collar 18 in the illustrated example is an annular, hollow, flexibly walled element the inside diameter of which is permanently bonded or secured to the outer surface of the tip 13.

Communicating with the hollow interior 19 of the stop collar 18 is a conduit 20 for expansion fluid to be directed to the hollow interior 19 of the stop collar when the collar is to be expanded following insertion into the heart. Conduit 20 extends from the collar 18 within the wall of tubular member 12, to a location along the length of the tubular member that would be disposed well outwardly from the chest wall of the patient. At this point, the conduit 20 is connected in communication with a flexible supply line 21 into which a fluid may be injected for expanding the stop collar 18.

The fluid could be air, pumped or otherwise directed into the supply line 21, so as to inflate the stop collar 18. Or, the pressure fluid could be a liquid similarly forced into the collar for radially expanding the same. When the device is to be withdrawn, the inflating medium is withdrawn from the collar through line 21 to deflate the collar.

In close proximity to stop collar 18 and to each other are sleeve-like electrodes 22, 24 formed of a suitable electrically conductive material, extending about the tubular member 12 and secured against axial displacement in respect to the tubular member and each other in any suitable manner. Electrodes 22 are impinged upon by electrical lead wires 26, 28 respectively which, as shown in FIG. 2, are embedded within the wall of the tubular member 12 and are angularly spaced within said wall from each other and from the conduit 20.

Lead wires 26, 28, extend longitudinally of and within the wall of the tubular member, to a location intermediate the ends of the tubular member, at which location they extend outwardly from said member. At their outer extremities, the lead wires are secured to plugs or jacks 30, 32 respectively constituting positive and negative connecting means attachable to corresponding posts of a source of electrical current.

In the preferred, illustrated embodiment, we also provide an auxiliary tube 34, which is secured to the tubular member 12 at a location between the check valve 17 and the tip 13, preferably a location near the fitting 14. An orifice 38 provides communication between the auxiliary tube and channel 15. The auxiliary tube 34 has a closure 37 which is permanently bonded to the wall of the auxiliary tube, and which is formed of a self-sealing rubber or equivalent material. A needle, now shown, may thus be inserted through the closure to provide a conduit for additional drugs, or to take blood samples. When the needle is withdrawn, the closure instantly seals itself.

OPERATION

In use, and assuming the existence of an emergency in which cardiac arrest has already occurred or is imminent, a syringe 40, having plunger 42 is fitted with needle 44. The syringe and needle are conventional devices, the needle being of the type typically employed as a spinal needle. The needle is inserted through skin "S" into the heart "H" as shown in FIG. 4. The insertion would be into the right ventricular cavity, the needle passing directly through the skin and endocardium, the preferred location of application being the left sternal margin, fourth interspace. During the insertion of the needle, a slight suction is maintained within the needle and syringe barrel, after which, following full insertion, plunger 42 is withdrawn to a greater extent as shown in FIG. 5. This draws a quantity of blood into the barrel of the syringe, as a blood sample and the syringe is now detached from the needle as shown in FIG. 6, leaving a small globule of blood at the outer end of the needle having the properties of a temporary sealant against the admission of ambient air or other contaminants.

Referring now to FIG. 7, the instrument 10 is now inserted, with the stop collar deflated, through the needle 44 as shown in FIG. 7.

When the tubular member 12 has been positioned through the needle 44 to an extent disposing the tip 13 at the inner, beveled extremity of the needle, the needle may be slightly withdrawn, as shown in FIG. 8, to an extend exposing the stop collar. The stop collar is positioned against the inner surface of the endocardium, as shown in FIG. 8, at this stage of the operation, and is now expanded as shown in FIG. 8 so as to provide a collar or abutment limiting the tubular member 12 against axial displacement.

As shown in FIG. 9, the next step is to withdraw the needle 44 completely. The needle, as shown in FIG. 9 and also in FIG. 3, is simply slid backwardly along the tubular member 12, to a non-interfering position. Thereafter, intracardiac drugs and/or other fluid medications may be administered by passage through the tubular member 12. In FIG. 3, for example, the fitting 14 is connected to a flask 46 through which fluids may be supplied. The flask 46 has an outlet tube provided with the usual regulator 48. If desired, other fluids can be simultaneously administered, through a needle or syringe applied through the closure or self-sealing valve 37 of auxiliary or branch tube 34.

The plugs or jacks 30, 32 are connected to corresponding posts of a cardiac pulse generator 50, of conventional design.

It will be understood, of course, that although a detailed, complete discussion of the various steps has been set forth above, these steps may be varied under certain conditions. Further, in practice the several steps shown in FIGS. 4-9 can be carried out by a trained, skilled team in seconds, since all the necessary apparatus will be maintained in a ready condition, awaiting a "Code 99" emergency.

In normal practice, before the insertion of the device, it would be the usual procedure to apply external cardiac massage. A second normal procedure would be to institute assisted ventilation, that is, mechanical or human techniques are employed to "breathe" for the patient. If, then, there is still no response to these initial resuscitative measures, implantation of the instrument 10 is effected in the manner described above, permitting intracardiac injection of adrenalin or other fluid stimuli. Concurrently or immediately following the injection of such fluids, electrical stimuli may be employed, through the provision of the electrodes 22, 24. It may be observed, in this regard, that these electrodes are so spaced from each other and from the stop collar 18 as to be in impinging relation to the wall of the myocardium, when the stop collar is in proper position against the heart wall. Conventionally, rhythmic electrical pulses are supplied, and at the same time, heart massage may be continued if desired. The invention is so designed as to stabilize the positioning of the medical instrument within the heart muscle, in such fashion as to assure to the maximum extent against heart damage should it be desired to apply massage procedures while the device is implanted. There is always a danger when the needle 44 is inserted, of striking a critical artery or vessel, and therefore, it is highly desirable that there be only one insertion. By combining the cannula with the electrode, this reduces the number of devices to be inserted. More importantly, however, the stabilizing means incorporated in the device eliminates the necessity of removing it should it be desired to return to or continue heart massage. Should the device be removed and then re-implanted, not only is valuable time lost, but also, the danger of striking a critical blood vessel is obviously multiplied by repeated implantation of the device.

It may also be desired to so form the wall of the tubular members 12 or 34, or both of them at selected locations along the length thereof, as to permit the insertion of needles directly through the material of the wall, as for example, in extracting fluids. The material of the wall can be selected so as to provide a self-sealing action when these needles are removed.

In some instances, the provision of self-sealing, tapping locations on the tubular member 12 may eliminate the need for branch tubes or the like, since any number of tubes can be connected to the main tube 12 if this expedient is incorporated in the construction.

Claims

We claim:

1. A transthoracic, cannula-type medical instrument for use in cardiopulmonary resuscitation procedures comprising;

a. a flexible tubular member having normally closed valve means therein and being provided with a tip adapted to be positioned within the right ventricle of the heart muscle through the chest wall of a patient and providing a channel having an opening for the flow of liquid to the heart or for the removal of blood aliquots therefrom:

b. stop means carried by said tubular member and located adjacent said tip, said stop means being radially expandable outwardly with respect to the axis of said tip into a position to engage the inner surface of the endocardium and limit subsequent axial movement of said tubular member;

c. means for applying an electrical stimulus to the heart muscle, including electrodes exposed on the outer surface of said tubular member;

d. said stop means and electrodes being so positioned with respect to each other that when said stop means are moved outward into contact with the inner surface of the endocardium, at least one of said electrodes will be held in contact with the heart muscle.

2. A medical instrument as in claim 1 wherein said means for applying an electrical stimulus further includes a path for an electrical current extending from the electrode within the wall of the tubular member and connectable remotely from the tip to a source of electrical current.

3. A medical instrument as in claim 1 wherein said electrode is in the form of a sleeve of electrically conductive material encircling said tubular member.

4. A medical instrument as in claim 3, further including an electrical lead embedded within and extending longitudinally of the wall of said tubular member, said lead at one end being electrically connected with said sleeve and at its other end being electrically connectable to a source of electrical current.

5. A medical instrument as in claim 1, further including a check valve within the tubular member to prevent backflow of said fluids.

6. A medical instrument as in claim 1, wherein said valve means includes a check valve in said member to prevent the backflow of fluids from the heart muscle, and a branch tube providing an auxiliary channel for liquids and connected with said member in communication therewith between said tip and check valve.

7. A medical instrument as in claim 1 wherein said stop means includes a hollow expansible element mounted upon said tip and further includes a conduit for an expansion fluid that extends within the wall of the tubular member in communication with the expansible element and with a source of expansion fluid under pressure, said means for applying an electrical stimulus including a pair of leads connected between the respective electrodes and a source of electrical current, said leads extending within the wall of the tubular member in angularly spaced relation to said conduit and to each other.

8. A medical instrument as in claim 7 wherein the expansible element is in the form of an annular collar encircling the tip of the tubular member and said electrodes are in the form of cylindrical sleeves that extend about the tubular member and are spaced longitudinally thereof from each other and from said collar.