U.S. patent number 3,817,241 [Application Number 05/226,835] was granted by the patent office on 1974-06-18 for disposable central venous catheter and method of use.
This patent grant is currently assigned to Edgar Braun, Henry and Carol Grausz, as trustees for Michael and Bradly Grausz. Invention is credited to Henry Grausz.
United States Patent |
3,817,241 |
Grausz |
June 18, 1974 |
DISPOSABLE CENTRAL VENOUS CATHETER AND METHOD OF USE
Abstract
A catheter composed of a length of flexible tubing composed of
nonreactive material permitting protracted intravenous placement
during periods of intensive care for intravenous feeding and
administration of drugs and for monitoring central venous pressure,
the catheter being provided with an electrical conductor extending
lengthwise of the tubing and providing an electrode at the distal
end positioned for sensing intrathoracic EKG activity unaffected by
material discharged from the distal end and additionally providing
such intrathoracic EKG activity simultaneously with the monitoring
of intravenous pressure.
Inventors: |
Grausz; Henry (Larkspur,
CA) |
Assignee: |
Henry and Carol Grausz, as trustees
for Michael and Bradly Grausz (N/A)
Braun; Edgar (N/A)
|
Family
ID: |
22850616 |
Appl.
No.: |
05/226,835 |
Filed: |
February 16, 1972 |
Current U.S.
Class: |
600/374; 600/395;
600/497 |
Current CPC
Class: |
A61B
5/283 (20210101); A61B 5/02152 (20130101); A61M
2025/004 (20130101) |
Current International
Class: |
A61B
5/0408 (20060101); A61B 5/042 (20060101); A61B
5/0215 (20060101); A61M 25/00 (20060101); A61b
005/04 () |
Field of
Search: |
;128/2.5D,2.5E,2.5F,2.5R,2.6E,2.6R,2.1E,DIG.4,348,349R,35R,404 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Other References
US. Catheter & Instrument Corp., 1957 catalog, page 8.
|
Primary Examiner: Kamm; William E.
Attorney, Agent or Firm: Warren, Rubin, Brucker &
Chickering
Claims
I claim:
1. In medical apparatus including a central venous catheter, an
intravenous feeding supply connected to the proximal end of said
catheter, and an electrocardiograph, the improvement
comprising:
a central venous catheter composed of nonreactive material having a
wall defining a longitudinally extending bore and an opening at the
distal end of said catheter and bore for fluid flow longitudinally
through said bore toward said distal end and for discharge through
said opening;
an electrical conductor carried by and extending lengthwise of said
wall and being electrically insulated from the exterior surface of
said wall and said bore;
an electrode connected to said conductor and mounted at said
exterior surface adjacent to but spaced proximally from said
opening; and
a terminal connected to said conductor adjacent said proximal end
of said catheter and being connected to said
electrocardiograph.
2. An apparatus as defined in claim 1,
said catheter having a length dimensioned for intrathoracic
placement of said distal end.
3. An apparatus as defined in claim 1,
a manometer; and
valve means connecting said manometer and source to said proximal
end of said catheter for selectively providing central venous fluid
administration or central venous pressure determination each while
simultaneously displaying EKG activity.
4. A central venous catheter for use with medical apparatus
including an intravenous feeding supply adapted for connection to
the proximal end of said catheter and an electrocardiograph,
comprising:
catheter means for insertion through a vein and into the thoracic
cavity of a patient but short of the heart and composed of
nonreactive material having a wall defining a longitudinally
extending bore and an opening at the distal end of said catheter
and bore for fluid flow longitudinally of said bore toward said
distal end and for discharge of fluid through said opening, said
catheter having a length for disposing said distal end in the
patients thorax;
an electrical conductor carried by and extending lengthwise of said
wall and being electrically insulated from the exterior surface of
said wall and said bore;
an EKG electrode connected to said conductor and mounted at said
exterior surface adjacent to but spaced proximally from said
opening; and
a terminal connected to said conductor adjacent said proximal end
of said catheter and being adapted for connection to said
electrocardiograph.
5. A catheter as defined in claim 4, said non-reactive material
being polyethylene.
6. A catheter as defined in claim 4, said non-reactive material
being Teflon.
7. A catheter as defined in claim 4, said non-reactive material
being Silastic.
8. A method comprising:
inserting into a patient's vein the distal end of a central venous
catheter having a longitudinally extending bore and an opening at
said distal end for fluid flow longitudinally through said bore
toward said distal end and for discharge through said opening and
an externally mounted electrode adjacent to but spaced proximal to
said opening;
advancing said catheter in the direction of blood flow in said vein
to position said distal end in the patient's thorax short of the
patient's heart and with the patient's blood flowing across said
electrode in advance of said opening;
connecting said electrode to an electrocardiogram; and
administering fluid through said catheter to said blood flow while
displaying EKG activity as sensed in the patient's blood upstream
from the point of fluid addition to said blood flow.
Description
Catheters of the character described are inserted into the superior
vena cava of patients as, for example, in intensive care wards for
the monitoring and treatment of heart patients or in any situation
where central venous pressure needs monitoring and intravenous
feeding of food or drug administration is required. Examples of
clinical situations include treatment of patients with an acute
myocardial infraction or patients with shock and myocardial disease
of any kind. In such cases, it is necessary to determine whether
the heart is failing or an arrhythmia occurs, at any time during
the first several days following the heart attack. Such information
is reflected in the central venous pressure and also by providing
and continuous monitoring of EKG activity. Prevalent causes of
death are arrhythmia and heart failure, both of which may require
the infusion of different medicines.
EKG activity is normally obtained by electrodes placed on the chest
of the patient which presents several disadvantages, notably the
interfering with the making of physical examination of the chest
area and the generally poor definition of EKG activity inherent in
external skin body placement of the electrodes, particularly in the
showing of the critically important P waves. A clear showing of the
P waves has distinct advantages in acute arrhythmia in
distinguishing supraventricular tachycardia from ventricular
tachycardia. The best and most dependable sensing and definition of
P waves is obtained either in the esophagus or in the superior vena
cava. Placement of electrodes in the esophagus is both dangerous
and impractical, and is likely in itself to affect undesirable
cardiac response. It is, accordingly, a feature and object of the
present invention to provide an electrode at the distal end of the
central venous catheter which is so positioned as to accurately and
dependably sense EKG activity with good resolution of P waves while
at the same time not being affected by the infusion of fluid or
medication from the distal end of the catheter or by the monitoring
of central venous pressure. Normally, the catheter will be inserted
into an anticubital vein and threaded up into the superior vena
cava for intrathoracic placement and optimum sensing of EKG
activity. The catheter may, of course, also be inserted through a
femoral vein or subclavian vein and, in each instance, the doctor
is able to monitor EKG rhythms during insertion to obtain accurate
intrathoracic location with the distal end of the catheter
approaching but being kept spaced from the heart. Engagement of the
distal end of the catheter with the heart is easily and immediately
seen in the EKG display.
Another feature of the present invention is that the electrode
placement, in addition to providing superior EKG display with the
entire chest area of the patient free for physical examination,
also provides an improved and constant electrical contact with the
blood adjacent to the heart and thereby avoids completely the
heretofore common occurrence of falsely set off alarms. The
electrode placement makes the location of the distal end of the
catheter always apparent which, in turn, increases the reliability
of central venous pressure records.
A critical and dramatic use of the catheter of the present
invention is in the emergency and urgency occasioned by a cardiac
arrest where restoration of life, if it is to be accomplished, must
be done in a very short time, up to about three minutes. In such a
situation, the attendant needs to establish respiration, that is,
breathe for the patient; monitor the EKG; and obtain access to the
central circulation for administration of drugs. A central venous
catheter is required since the medicine must reach the heart and
not be merely injected into an arm or other part of the body due to
lack of blood circulation. At the same time, a continuous
electrocardiograph recording is required to signal the
administration of the right drugs as conditions change. At present,
the procedure is to hook up an EKG apparatus to the patient with
the time consuming preparation and placement of the required four
electrodes, then inserting a catheter to obtain access to the
circulation, and initiating breathing for the patient. The time
required to hook up the four leads of the EKG apparatus becomes
critical. With the catheter of the present invention, the obtaining
of the EKG display and access to the central circulation of the
patient is effected with one maneuver, viz., the insertion of the
catheter which may be done in a matter of seconds. Changes in size
and direction of the P waves provide an immediate indication of the
desired entrance of the catheter into the thorax.
Instruments have been designed and used for the sensing of EKG
activity within the superior vena cava and within the chambers of
the heart itself. The prior art suggests the use of electrodes on
specially designed catheters for use by cardiologists in performing
heart catheterization where the distal end of the catheter is
manipulated into and through the chambers and connecting valve of
the heart for removal of blood, inserting of dye, measuring EKG
activity, and shocking or pacing the heart. See U.S. Pat. Nos.
3,533,403 and 3,568,660. These catheters are in the nature of
special surgical instruments which are inserted into the body for
the relatively short period of time required to accomplish the
specific objective noted. Such catheter instruments have not been
designed or constructed for the placement and use of the present
catheter, that is, one which may be left in the body over a
protracted period of several days; to provide simultaneous central
venous fluid administration and sensing of intrathoracic EKG
activity; and simultaneous monitoring of central venous pressure
and intrathoracic EKG activity.
The invention possesses other objects and features of advantage,
some of which of the foregoing will be set forth in the following
description of the preferred form of the invention which is
illustrated in the drawing accompanying and forming part of this
specification. It is to be understood, however, that variations in
the showing made by the said drawing and description may be adopted
within the scope of the invention as set forth in the claims.
Referring to said drawing:
FIG. 1 is a pictorial view of the apparatus of the present
invention;
FIG. 2 is a fragmentary, cross-sectional view of a catheter
constructed in accordance with the present invention;
FIG. 3 is a cross-sectional view taken substantially on the plane
of line 3--3 of FIG. 2;
FIG. 4 is a cross-sectional view taken substantially on the plane
of line 4--4 of FIG. 2;
FIG. 5 is a cross-sectional view taken substantially on the plane
of line 5--5 of FIG. 2; and
FIG. 6 is a pictorial representation of the present catheter in its
position of use in the superior vena cava.
The catheter of the present invention is of the disposable central
venous type and is composed of flexible tubing having a length
adapted to extend into the superior vena cava and composed of
nonreactive material permitting the catheter to remain in place for
a protracted period of several days during the course of
observation and treatment; an electrical conductor 12 carried by
the tubing and extending lengthwise thereof and being electrically
insulated from the interior and exterior walls 13 and 14 of the
tubing; an electrode 16 connected to conductor 12 and mounted at
the exterior surface of the tubing adjacent to but spaced from the
distal end 17 thereof; and a terminal 18 for conductor 12 adjacent
the proximal end 19 of the tubing for connection by lead 21 to an
electrocardiograph 22.
The proximal end 19 of the catheter is provided with an adapter 20
which is, in turn, connected by a length of tubing 25 to the
standard three-way manual cock valve 23 which has conduit
connections to the base of a manometer tube 24 and to the feed
conduit 26 of an I.V. bottle 27. Accordingly, valve 23 may be
manually turned between an off position, a second position
connecting the manometer 24 to the catheter for reading of central
venous pressure, and a third position connecting the catheter to
I.V. bottle 27 for infusing fluid through the catheter into the
blood stream. Medicine may be injected into the catheter by means
of a needle inserted directly into the tubing.
In distinction to the prior art, catheter instruments mentioned in
the foregoing which can be tolerated by the body for a very brief
period, the catheter of the present invention is constructed of
nonreactive material. Nonreactive material is defined as one which
the body does not reject or react to. The preferred material is
polyethylene. Two other materials, Teflon and Silastic, may also be
used. It is essential that the present catheter be made of a
substance which the body will tolerate for extended periods of
time, several days, without causing an inflamatory reaction.
Another critical feature of the present catheter is the location of
electrode 16. It is essential that this electrode be located on the
exterior side 14 of the catheter out of contact with the material
discharged from the distal end 17 so as to be electrically
unaffected thereby. For the same reason, electrode 16 needs be
spaced slightly from tip 17 so that a droplet of saline or other
material will flow away from the tip without touching electrode 16
and producing an attendant blip on the electrocardiogram. The
essential feature of the present invention is that a continuous and
accurate EKG display is obtained simultaneously with the infusion
into the blood stream of fluid from the distal end of the catheter.
Thus, an instantaneous observation may be made of drug
administration and EKG activity which is of critical importance in
certain instances, as in the treatment of cardiac arrest.
Similarly, immediate observation of EKG activity is provided with
the introduction of all types of I.V. material. Electrode 16 should
be spaced from tip 17 by a distance of about one-eighth inch.
Conductor 12 is here embedded in the wall of tubing 11 and is
turned to the outside surface 14 adjacent distal end 17 to provide
electrode 16. Alternatively, the outer wall portion may be removed
to expose the conductor. In a similar manner, the opposite end of
conductor 12 is turned out and electrically connected to the base
of terminal 18 secured to the proximal end of the catheter.
Terminal 18 is here formed with a circular socket 31 dimensioned
for receipt of the conventional pin end on EKG conductor 21 and
with a set screw 32 for securing the conductor pin in place. Only a
fine wire size is required for conducting the EKG potential.
Embedding of conductor 12 in the catheter wall provides the
required electrical insulation. The requirement of a minimum wire
size enables the use of the invention with standard size central
venous pressure catheters, e.g., 22 gauge and 18 gauge, and in
usual catheter lengths.
* * * * *