U.S. patent number 3,854,477 [Application Number 05/348,611] was granted by the patent office on 1974-12-17 for apparatus and method for the application of a continuous somatic nerve block.
Invention is credited to Stuart L. Smith.
United States Patent |
3,854,477 |
Smith |
December 17, 1974 |
APPARATUS AND METHOD FOR THE APPLICATION OF A CONTINUOUS SOMATIC
NERVE BLOCK
Abstract
A method of applying an analgesic for controlling postoperative
pain, where somatic nerves in the patient's body are severed, as
during an operation. A stylette is used to thread a porous infusion
tube through the patient's body wall along a course which traverses
the nerves to be blocked After the infusion tube is properly
located, analgesic delivered into the tube will pass through the
wall of the tube into the patient's body at the nerve locations.
The stylette is a curved rod whose diameter is the same as the
infusion tube. The point at the leading end is rounded. A stub at
the trailing end connects with the infusion tube, all in an
arrangement to permit effective threading and placement of the
tube.
Inventors: |
Smith; Stuart L. (Lakewood,
CO) |
Family
ID: |
23368770 |
Appl.
No.: |
05/348,611 |
Filed: |
April 6, 1973 |
Current U.S.
Class: |
604/512; 604/175;
604/528 |
Current CPC
Class: |
A61M
25/0069 (20130101); A61M 25/09 (20130101) |
Current International
Class: |
A61M
25/00 (20060101); A61m 005/14 (); A61m
025/00 () |
Field of
Search: |
;128/1R,213,33R,348,35R |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Pace; Channing L.
Attorney, Agent or Firm: Van Valkenburgh, Lowe & Law
Claims
I claim:
1. A method for placing the porous section of an infusion tube,
having a porous section and a non-porous section, in the body wall
of a patient, for applying an analgesic to control postoperative
pain where somatic nerves are severed by an incision in the
patient's body wall, which includes the steps of:
a. locating the paths of the nerves severed by the incision and
selecting a course in the patient's body wall which traverses the
severed nerves between the spinal column and the points of
severance, which is spaced from the incision in undamaged tissue
and which is located between layers of fascia and/or muscle
adjacent to the somatic nerves to minimize disruption of body
tissue and the amounts of analgesic needed to reach the nerves;
b. implanting the porous section of the infusion tube in the
patient's body wall at the selected course and alongside the
severed nerves, with the non-porous section of the tube extending
from the patient's body wall at one end of the course; and
c. delivering fluid analgesic into the tube whereby the same will
flow into the porous section within the patient's body wall and
thence to tissue including nerves alongside the porous section of
the tube.
2. In the method set forth in claim 1, wherein:
said course is within the fascia forming the sheath of the rectus
muscle.
3. In the method set forth in claim 1, wherein:
said course is in the cleft between the internal oblique muscles
and the transversus abdominus muscles.
4. In the method set forth in claim 1, wherein the infusion tube is
implanted in the patient's body wall by the steps of:
a. connecting one end of the tube to the stub end of a stylette
having substantially the same diameter as the external diameter of
the tube, a curvature generally correlated with the selected course
through the body wall and a length greater than the course by a
short distance sufficient to facilitate handling the stylette;
b. inserting the point of the stylette into the patient's body wall
at one end of said course, threading the same through the course at
a depth which permits the stylette to lie alongside the severed
nerves and projecting the point of the stylette from the body wall
at the opposite end of the course; and
c. pulling the stylette through the selected course in the
patient's body wall whereby to pull the infusion tube into
place.
5. In the method defined in claim 1, wherein the steps of
implanting the infusion tube in the patient's body wall are
performed during the operation while the incision in the patient's
body wall is open, whereby to facilitate guiding the stylette along
the selected course by reaching into the incision.
6. In the method defined in claim 5, including the step of:
nicking the skin of the patient's body wall at the point where
threading of the stylette commences and nicking the skin at the
patient's body wall at the opposite end of the course where the
point of the stylette projects from the patient's body.
7. In the method defined in claim 1, wherein:
the analgesic is administered by the step of connecting a syringe
carrying the analgesic to the tube.
8. In the method defined in claim 1, wherein:
the analgesic is administered by the step of connecting a bottle
containing the analgesic to the tube.
9. A stylette for threading a small diameter infusion tube through
a selected distance along a curving course of a patient's body wall
such as within the fascia forming the sheath of the rectus muscle
and comprising, in combination with the tube:
a. a slender, smooth, rod-like member having a diameter
substantially the same as the external diameter of the infusion
tube, having a length in excess of the aforesaid selected distance
sufficient to handle the stylette while inserting it into the
patient's body and a curvature which is generally correlated with
the curvature of the patient's body wall along the selected
distance;
b. a dulled point at one end of the stylette; and
c. an abutment at the opposite end of the stylette to abut with an
end of the tube and a means at this opposite abutment end to
securely connect the abutting end of the tube thereto.
10. In the stylette defined in claim 9, where the curvature is
essentially a segment of an elipse with the smaller radius of
curvature being at the point end of the same.
11. In the stylette defined in claim 9, wherein the point is smooth
and rounded to minimize the chance of the point piercing or cutting
a vein or a nerve.
12. In the stylette defined in claim 9, wherein:
the point of the stylette is generally chisel-shaped with all edges
being rounded at a radius from between 1/64 -- 1/32 inch.
Description
The present invention relates to methods and apparatus for
producing localized analgesia and more particularly, to
improvements in the application of analgesics for controlling
postoperative pain.
The postoperative pain resulting from surgery, and especially from
abdominal surgery can become almost unbearable resulting not only
in intense discomfort, but also restricted and shallow breathing
which can lead to atelectasis. To relieve the patient, narcotic
analgesics are commonly administered. However, in doing so, care
must be exercised to avoid desensitizing or immobilizing the
patient's normal body functions and also, care must be exercised to
avoid addiction to the narcotic.
Recognizing these factors, local nerve blocks, similar to blocks
used for surgery, are sometimes administered by injection at
critical points into the patient's body. For example, an
intercostal nerve block for upper abdominal operations has been
heretofore used with indifferent success by multiple injections.
However, this entire approach to the problem has proven to be
unsatisfactory, especially in an operation where an array of nerves
must be desensitized.
The present invention was conceived and developed with the
foregoing considerations in view, and the invention comprises, in
essence, a procedure wherein an infusion tube having a selected
porous reach is threaded into the patient's body to traverse and
lie alongside a selected array of nerves, with the porous reach at
the nerves. The tube is then prepared to receive an analgesic
solution as either an intermittent or a continuous infusion which
will be directed through the tube and to the nerve, or nerves.
The invention is especially suited for chest or abdominal surgical
operations wherein it is desired to block the somatic nerves
severed by the incision to relieve the postoperative pain of the
incision. This is rendered possible because somatic nerves are
associated with each other in such a manner as to enable the
surgeon to usually select an easily defined, direct path through
reaches between the patient's muscle and fascia structures which
will be adjacent to and will traverse the nerve system to be
blocked. The selected path will be first traversed by a stylette
for threading the infusion tube into place without damaging any
tissue. In considering possible somatic nerve block paths, it was
found that in every practical instance, the path would
approximately define a segment of an elliptical curve, a factor
which establishes the design of stylettes for the specific purposes
as hereinafter described in detail.
An excellent example of surgical operations where the invention is
especially effective, is found in the group of abdominal operations
where a vertical incision is made through a rectus muscle and it
becomes desirable to block any portion of the group of the nerves
which enter the sheath of this muscle and which may include the
sixth through the 12th thoracic nerves and the first lumbar nerve.
Accordingly, the description of the invention, as hereinafter set
forth, relates primarily to the blocking of a portion of this group
of nerves. However, it is to be understood that the teachings of
the invention can easily be applied to other nerve groups as the
occasion may arise.
It follows that a primary object of the invention is to provide a
novel and improved method for a continuous or intermittent,
selectively-regulated introduction of an analgesic solution into
specific regions within a patient's body to most effectively
minimize postoperative pain.
Another object of the invention is to provide a novel and improved
method for controlling postoperative pain which will be restricted
to local regions of the patient's body, which requires only a
minimum amount of a comparatively mild analgesic of a type which is
easily and quickly metabolized by the patient and which will
usually eliminate the need for narcotic analgesics.
Another object of the invention is to provide a novel and improved
method for controlling postoperative pain, resulting from an
abdominal operation, which not only minimizes the patient's pain
and discomfort, but also avoids abnormal and restricted breathing,
a serious postoperative hazard.
Another object of the invention is to provide a method for the
application of analgesics for relief of postoperative pain which
incorporates a novel and improved arrangement of components and
procedures permitting the placement of the components thereof
within the patient's body as a procedure associated with the
operation itself and while the patient is still under
anesthesia.
Another object of the invention is to provide a novel, improved and
simplified apparatus for accomplishing the introduction of an
analgesic solution into specific regions of a patient's body which
may function in an automatic manner, requiring a minimum of
attention when in use.
With the foregoing and other objects in view, all of which more
fully hereinafter appear, my invention comprises certain
procedures, sequences and steps, and combinations, constructions
and components, all as hereinafter more fully described, defined in
the appended claims and further exemplified in the accompanying
drawings in which:
FIG. 1 is a front view anatomical diagram of the abdominal muscle
structures with a portion of the right rectus muscle being removed
to illustrate the reach of the sixth through the 12th thoracic
nerves and the first lumbar nerve which will lie, generally,
against the sheath of the rectus muscle, the view also indicating
the line of a vertical incision through the right rectus muscle and
the approximate location of an infusion tube within the sheath of
the rectus muscle to administer an analgesic according to the
principles of the invention.
FIG. 2 is a diagrammatic sectional view of the right side of a
patient's body wall to illustrate, in an approximate manner, the
path of a thoracic nerve, the view being approximately from the
indicated line 2--2 at FIG. 1, but on an enlarged scale.
FIG. 3 is a fragmentary sectional view of the frontal portion of
the abdominal wall as taken from the indicated line 3--3 at FIG. 1,
but on an enlarged scale, the figure showing the terminal reaches
of the somatic nerves.
FIG. 4 is a fragmentary portion of the showing at FIG. 3, but on a
further enlarged scale to better illustrate the manner in which the
rectus muscle is confined within its sheath and also, suitable
locations for an infusion tube adjacent to the somatic nerve. FIG.
5 is a plan view of a stylette which is formed to permit threading
an analgesic infusion tube through the body structure according to
the invention.
FIG. 6 is a perspective fragmentary view of the stylette and a tube
which is to be attached thereto, the view being on a greatly
enlarged scale with the components being disconnected from each
other and with portions of each component being broken away to
conserve space.
FIG. 7 is a perspective view of one type of syringe which may be
used to supply analgesic to the infusion tube.
FIG. 8 is a fragmentary side view of the point of the stylette, on
a greatly enlarged scale, to better illustrate the manner in which
the edges of this point are rounded and illustrating further, in a
diagrammatic manner, a typical nerve which is being contacted by
the point of the stylette.
FIG. 9 is a sketch illustrating a patient undergoing abdominal
surgery and a surgeon applying the stylette in accordance with the
principles of the invention.
FIG. 10 is a sketch showing the patient after surgery, with the
infusion tube applied to the patient and with a bottle connected to
the infusion tube to introduce analgesic in accordance with the
invention.
FIG. 11 is a fragment of the sketch shown at FIG. 10 but
illustrating a pair of infusion tubes applied to the patient to
introduce analgesic to the somatic nerves at both sides of the
patient's body.
FIG. 12 is a view of a patient's back showing, in dotted lines,
another reach, at the patient's rib cage, where analgesia may be
applied to the thoracic nerves as at a location which is suitable
for relieving the postoperative pain of a chest operation.
The advantages of a mild analgesic over narcotics for the relief of
pain are well known. However, a major limitation in the use of
analgesics to control the postoperative pain of major surgery has
been the difficulty in effectively applying the analgesic to block
the nerves injured by the surgery. The present invention discloses
a method where the analgesic may be applied as between layers of
tissue where the nerves to be blocked are located, and preferably
near but not at the surgical incision. This is desirable because
the region of the patient's body which is desensitized by the
analgesic is then kept to a minimum.
An ideal analgesic for the present invention is Xylocaine, commonly
sold as Lidocaine, and Lidocaine is representative of other
effective, local and infiltrative analgesics which function in a
similar manner. To test the effectiveness of the procedures which
constitute the invention, a number of abdominal surgical operations
were performed and the postoperative pain, controlled as
hereinafter described, was controlled by a 1 percent commercially
packaged Lidocaine solution as sold by Astra Pharmaceutical
Products, Inc. of Worcester, Mass.
It was discovered that the total amount of Lidocaine required was
not large. The Lidocaine could be administered either continuously
or intermittently at a rate of approximately 5-10 cc/hr., that is,
50 to 100 mg/hr, and this amount would usually permit the patient
to remain quite comfortable. Considering the nature of the surgery,
this is a surprisingly small dosage when recommended intravenous
doses of Lidocaine, for other purposes, may be as much as 300
mg/hr. Accordingly, this application of analgesia is comparatively
safe to the patient.
The several abdominal surgical operations which tested the method
demonstrated that the total amount of analgesic needed could vary
considerably depending upon the individual patient's needs and
also, upon the type of operation performed. For example, in a
series of operations, the smallest total amount required was 950
mg. and the largest total amount required was 14,600 mg. In
considering these total amounts of analgesic, the time involved in
administering the same is also a factor and the times involved in
applying the amounts noted varied from 2 to 8 days. Tests
demonstrated that the physician could easily effectively regulate
the amount of analgesic any patient would need.
Lidocaine is considered to be an effective analgesic with minimal
side effects and is rapidly metabolized as it is absorbed into the
patient's system. A careful surveillance of the patients tested
failed to demonstrate any instance of bradycardia, hypotension or
central nervous aberrations. Clearly, the introduction of a small
quantity of a mild analgesic to block injured nerves at a point
close to the surgical incision appears to be an ideal way to
provide effective relief of pain and a tranquil postoperative
course of events.
Certain solutions to supplement and to control this application of
Lidocaine are desirable and as such, are generally known. To avoid
fibronous clotting in the apparatus through which the Lidocaine is
applied, it is desirable to add a small amount of aqueous heparin,
for example, 50 units of the same per 50 cc bottle of a 1 percent
lidocaine solution was found to be adequate, a unit being 0.01
mg.
Other analgesics suitable for this purpose include procaine,
commonly known as Novocaine, teracaine and cyclaine. A skilled
surgeon will know the toxicities and the effectiveness of these
analgesics and also will know his patient sufficiently well as to
be able to select a proper analgesic and to use the proper amount
of analgesic for a given operation.
FIGS. 1 - 4 exemplify, in a somewhat diagrammatic manner, the nerve
system and typical nerve branches which are encountered in
abdominal surgery where an incision 20 in the body wall is a
vertical incision through the right rectus muscle R adjacent to,
but offset a short distance from, the median line of the patient's
body. This is a common, preferred type incision for many abdominal
operations. The incision line 20 will cut through several
right-side thoracic nerves and will cut a lumbar nerve if the
incision is to extend to the lower part of the abdomen. As shown at
FIG. 1, this nerve system in the abdominal wall forms a ladder-like
array of individual nerves which include the sixth through the 12th
thoracic nerves indicated at T6 - T12, respectively, and also the
first lumbar nerve L1. Only the right-side nerves are shown, but
the left-side thoracic and lumbar nerves present a similar
pattern.
A typical thoracic nerve T9 is diagrammatically indicated at FIG.
2. The nerve extends from the spinal cord S between vertebrae to
lie against the underside of a rib as it extends about the
individual's body, and thence downwardly and across the abdomen
after emergence from the intercostal space. As indicated, the
typical thoracic nerve T9 has intermediate branches, including one
branch at the back of the rib cage and another branch at the side
of the rib cage, but the main branch of the nerve extends across
the individual's abdominal wall to terminate a short distance
beyond the front median line, with the right-side and left-side
thoracic nerves overlapping each other a short distance in this
median region.
The terminal portions of the 11th right-side and left-side thoracic
nerves, T11 and T11', respectively, are shown in further detail at
FIGS. 3 and 4. These thoracic nerves, extend from their respective
rib spaces, to lie against fascia of the transversus abdominus
muscle 22. Thence, each nerve extends to its respective rectus
muscle R entering the fascia to lie upon the inner side of the
posterior sheath of this muscle. Traversing its rectus muscle, each
opposing nerve, T11 and T11', terminates at the linea alba 23, with
respective branches, 24 and 24', extending outward through the
superficial fascia to the skin and with other branches 25 and 25',
extending inwardly to the peritoneum. It is to be noted that these
branches extend across the median line of the individual's body to
overlie each other and it follows that should the incision 20 be
located close to the median line, the nerve ends of the left
thoracic nerve will also be severed by the right-side incision 20,
as will be hereinafter discussed further.
Should a surgeon contemplate blocking the thoracic nerves for a
surgical operation, he must locate the blockage points according to
the extent of the incision to include a proper array of thoracic
nerves and, if necessary, the lumbar nerve. The concept of such
nerve blocks for surgery is not new, the same being accomplished
with a series of spaced injections of an analgesic alongside the
critical nerves. However, such a procedure has not been used for
postoperative care since repeated groups of injections every few
hours are extremely inconvenient and cannot be tolerated.
The present invention avoids the latter objections and provides a
novel mode of blocking the critical nerves by implanting a porous
tube 30 in the body wall of a patient which will permit either a
continuous or intermittent flow of analgesic into the body wall to
desensitize the several nerves.
Several tube constructions used in surgery primarily as drainage
tubes may be used in the present invention for the introduction of
the analgesia into the body wall. The basic properties and features
of such a tube are that it be neutral to body tissue, that it be
comparatively small in diameter so that it may be threaded into the
body wall without undue discomfort, that it be tough, smooth and
have substantial tensile strength so that it may be easily pulled
from the patient after it has served its purpose and that this tube
be porous in the portion where it is inserted into the patient's
body wall and non-porous at the portion where it extends from the
patient for connection to a dispenser means, such as a syringe for
delivering the analgesic to the patient.
A tube suitable for the purpose at hand is exemplified at FIG. 6.
This tube 30 is formed of a synthetic resin, such as polyvinyl
chloride. Such tubing may be obtained from various surgical supply
houses. For example, tubing sold under the designation Tygon may be
obtained from Zimmer Company of Warsaw, Ind. The tubing is
conventionally used for drainage purposes in a number of various
surgical operations. The tubing is very strong, quite supple and
pliable and it is ideally suited for the purpose at hand. It is
also available in different diameters varying from 1/8-in.-1/4-in.
This tubing is provided with openings 31 in the side walls, as
illustrated at FIG. 6. These openings which permit the tubing to
function as an infusion tube may be of various sizes, shapes and
patterns and it is a simple matter for a surgeon to obtain from the
companies supplying the same, a suitable supply of tubing having
the openings located according to any desired pattern. In the
present invention, the openings will be located in a tube along one
reach which will be embedded into the patient's body when in use.
Another portion at one end of the tube will have no openings so
that it may be extended from the patient's body for connection with
a dispenser means.
This tube must be threaded through a selected course in the body
wall of a patient, as hereinafter further described, and a long
rigid stylette 40, such as indicated at FIGS. 5 and 6, is provided
for this purpose. The stylette will have the same diameter as the
tube, a blunted point 41 at one end to facilitate pushing it
through body tissue and a threaded stub 42 at the other end which
will be tightly fitted into the tube 30 to pull the tube into place
as the stylette is extended through and from the patient's body
wall. The blunted point 41 is preferably shaped with inclined flat
surfaces 43 to produce a wedge-shaped appearance with a leading
edge 44 having a form suggestive of a chisel. However, this edge 44
is rounded in all directions as illustrated to provide a smooth,
blunted polished edge which will not cut nor crush a nerve or blood
vessel it may encounter when being pushed through the patient's
body wall, and as such, the side radius of this edge 44 may be
selected to be in the range of 1/64th inch to 1/32nd inch to be
comparable to the diameter of nerves or blood vessels which may be
encountered in using the stylette to more easily push such nerves
or blood vessels aside and out of the way, whenever they are
encountered, as in the manner suggested at FIG. 8.
The dispensing means for introducing the analgesia into this tube
may be a conventional syringe 50, as illustrated at FIG. 7, which
has its discharge end modified to form a stub 51 to receive a
connective coupling 52 at the end of the tube 30. Also, the
dispensing means may be a conventional infusion pump or a
conventional drop dispenser 55 which may be mounted above a patient
to dispense the analgesic at a continuous slow rate through a tube
56 which connects with the tube 30, as shown at FIG. 11. The
dispenser 55 is of the same type which is commonly used for
introducing fluids into a patient's blood vessels.
From consideration of the patient's body structure and nerve
arrangement at the abdomen, it becomes apparent that the surgeon
must select a suitable path in the patient's body wall for proper
introduction of the stylette. Since the lumbar and thoracic nerves
form a ladder-like array across the patient's abdomen, it was found
that one suitable path for location of the infusion tube was near
the outer edge of the rectus sheath, but within the sheath as
indicated at FIGS. 3 and 4. This location is ideal in many
respects. The path of the tube will traverse the group of nerves to
be desensitized but will parallel the muscle tissue of the rectus
sheath at a location between fascia and muscle tissue where it may
be easily guided along the desired course without the necessity of
being pushed through intervening fascia, excepting, of course, at
the points of insertion into and extension from the body as will be
hereinafter described. An alternate location for the infusion tube
may be alongside the thoracic nerves in the cleft between internal
oblique muscles 21 and the transversus abdominus muscles 22 as
indicated in broken lines at 30a at FIG. 4. Again at this region,
the tube may lie between layers of muscle and fascia with a minimum
of injury to the tissue.
The location of the infusion tube within a patient's body wall will
determine the form and the size of the stylette 40 which must be
threaded through the patient's body wall at the selected location,
as will be described. It was found that the locations above
mentioned, at the edge of the rectus sheath and alongside the
oblique and transverse abdominal muscles, would define curved paths
which may generally be described as being elliptical. Thus, the
stylette will preferably be curved in a similar manner, which may
be described as a segment of an ellipse. Preferably, the stylette
will have maximum curvature near its point and minimum curvature,
more closely approaching a straight portion, at the opposite,
connective end of the stylette. However, since the stylette must be
threaded completely through the selected course in the patient's
body wall, the variation of curvature from one end of the stylette
to the other cannot be great. Other uses of the invention, other
than for an abdominal operation, are also possible and in each
instance considered, it was found that a similar curvature of the
stylette was desirable to that above described, although the size
of the stylette and the degree of curvature needed would vary with
each use and with the size of the patient.
The manner in which the infusion tube is placed into a patient's
body with the aid of a stylette is illustrated at FIG. 9 and the
manner in which the infusion tube 30 is ultimately positioned in
the patient's body is illustrated at FIG. 10. Before a surgical
operation is performed, the surgeon will determine the length and
desired location of the infusion tube to be placed in the patient's
body wall and select a stylette having suitable curvature for such
insertion. The infusion tube, including a reach which is to be
extended from the patient's body is secured to the stub 42 of the
stylette preparatory to the operation. The surgical operation will
proceed in the regular manner and prior to the steps of closing the
incision, the infusion tube will be placed in the abdominal
wall.
Ordinarily, the stylette will be threaded into the patient's
abdominal wall at a point below the incision to parallel the
incision and it will emerge from the abdominal wall at a point
above the upper end of the incision. Since the point of the
stylette is comparatively dull, it cannot penetrate a patient's
skin. Thus, the first necessary step is to make a tiny cut 60 with
a surgical knife where the stylette is to enter. The stylette is
then pushed into position and literally "popped" through the fascia
covering the rectus muscle. It is then threaded alongside the
rectus muscle, extending upwardly, with the surgeon reaching into
the patient's abdomen as indicated at FIG. 9, or in any other
suitable manner to guide the stylette along its selected path. The
slightly varying curvature of the stylette enables the surgeon to
twist and rotate the stylette a small amount to assist in guiding
it to its position. When the point of the stylette reaches the
upper terminus of the insertion, the point is turned outwardly and
again literally "popped" through the fascia to push against the
skin. Since the point of the stylette is easily located as it
flexes the skin outwardly, the surgeon may again nick the skin 61
to permit the point of the stylette to extend from the patient's
body.
The process is completed by pulling the stylette from the patient's
abdominal wall to place the infusion tube at its final selected
position. The end of the reach of the porous infusion tube will
slip into the abdominal wall, as illustrated in FIG. 10. The other,
non-porous end of the tube 30 is connected to a syringe 50 for
intermittent introduction of analgesic or to an extension tube 56
which may be connected to a bottle 55 for continuous introduction
of analgesic, as illustrated at FIG. 10. Subsequent to the steps of
placing the tube, an initial dose of analgesic is given and the
surgery is then completed by closing the incision in a routine
manner.
As the patient recovers, selected amounts of analgesic may be
delivered into the infusion tube depending on needs of the patient
and thereafter a floor nurse on duty may care for the patient by
regulating the rate of analgesic flow depending upon the amount
needed to control the postoperative pain in the patient.
The effectiveness of the present invention was demonstrated through
a series of operations at the Lutheran Hospital and Medical Center
of Wheat Ridge, Col. To provide a basis for comparison, a series of
21 matching abdominal operations were performed by various staff
surgeons and each operation required an average of 15.7 doses of
injectable narcotics, such as morphine, to control postoperative
pain. In contrast, 52 abdominal operations were performed, wherein
infusion tubes were applied as disclosed herein, as a supplement to
the operations and to control postoperative pain. This
supplementary procedure was successful in 51 of the 52 operations
and of these, only 4 patients required an injection of a narcotic
and of the 4 only one required more than one injection.
Moreover, of the 51 successful operations, no complications ensued
as a result of the use of the infusion tube, or tubes, or of the
use of the small quantities of the comparatively mild analgesic.
These results clearly demonstrate the utility of this method for
controlling postoperative pain with mild analgesics.
As heretofore described, the right side and left thoracic nerves
overlap each other at the front midline of a patient and in
surgical operations close to the midline, there exists the
possibility of severing both right side and left side thoracic and
lumbar nerves. If this is apt to occur, the use of analgesia at
only one side of the patient may be ineffective and two infusion
tubes 30 and 30' must be used as in the manner illustrated at FIG.
11. Each infusion tube is placed in the abdominal wall of the
patient as heretofore described and each tube may receive the
analgesic independently if continuous feeding is desired, or
through a "V" 35 connecting the tubes to a common source tube 53,
as shown at FIG. 11.
The invention, in its broader aspect, can include other than
abdominal operations. FIG. 12 shows, diagrammatically, the use of a
tube 30 placed in a patient's back to desensitize the thoracic
nerves. By examination of the pattern of a thoracic nerve, at FIG.
2, it is seen that another location may be located as at 30b. A
stylette of similar form, with a curvature essentially the same as
described, can be used for this purpose. This particular
application is directed toward effectively reducing the
postoperative pain of chest surgery where entry must be made
through the rib cage.
Yet other applications of analgesia may be advantageously applied
to a patient to relieve him of postoperative pain, it being
essential for the surgeon to first locate and map the nerves which
will be injured by the surgery and to determine an advantageous
location where an infusion tube can be placed into the body of the
patient alongside the critical nerves. This generally will be done
at the time of the operation and subsequently the postoperative
procedure will involve only the infusion of selected amounts of
analgesic.
I have now described my invention in considerable detail and it is
obvious that others skilled in the art can devise alternate and
equivalent components for the same and develop alternate and
equivalent sequences and steps. Hence, I desire that my protection
be limited not by the construction, sequences and steps described,
but only by the proper scope of the appended claims.
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