Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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Blood Evacuating System and Method of Use Thereof
TECHNIC.'AL FIELD
The present invention re:Lates generally to an apparatus
and method for collecting fluids and the reinfusion of the
fluids to a patient, and particularly to a blood evacuation
system adapted for' autotransfusion. More specifically, the
present invention is directed to a blood evacuation system
that permits a disposable inner evacuation bag to be
separated from an outer container for reinfusion so that
another evacuation bag may be inserted inside the container
to continue blood evacuation.
BACKGROUND ART
Blood evacuating apparatuses are commonly used in
autotransfusion to evacuate and collect autologous blood
from the collectic>n chamber of a chest drainage unit.
Autotransfusion refers to the reinfusion of a patient's own
blood, known as autologous blood. Autotransfusion is the
preferred method of reinfused since the blood being
transfused is the patient's own blood, therefore eliminating
problems over blood type incompatibility and exposure to
blood carrying diseases such as hepatitis, AIDS, etc.
Moreover, autologous blood is more fresh than stored blood
supplied by a donor and also contains the patient's own
antibodies.
One type of autotransfusion, referred to as "post-
operative" autotransfusion, is the transfusion of the
patient's own shed blood following surgery where drained
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blood is collected and reinfused into the patient. Post-
operative autotransfusion is limited in use since there are
strict guidelines for the kind of blood which can be
reinfused. Currently, the only post-operative blood believed
suitable for autotransfusion is mediastinal blood, i.e. the
blood which comes from the anatomical space or cavity in the
chest.
Presently, chest drainage units are commonly used in
the post-operative care of patients having surgery
involving the chest cavity. Chest drainage units remove
fluids and air from inside the chest cavity using tubing
connected to the patient's chest cavity which drains the
fluid and air into a collection chamber of the chest
drainage unit. The chest drainage unit is attached to a
source of vacuum which applies a suction to the tubing and
draws the trapped fluid and air from the chest cavity and
into the collection chamber. Once collected, the blood may
be evacuated from the collection chamber using an
autotransfusion pump or blood evacuation bag.
The use of a blood evacuation bag in autotransfusion is
well known in the art. For example, U.S. Patent No.
5,380,314 to Herweck et al. discloses a blood collection bag
having an internal spring that resiliently biases the bag
into a fixed shape prior to use while concurrently inducing
a negative pressure therein in order to manually draw blood
from the collection chamber of the chest drainage unit.
However, one disadvantage with the '314 apparatus is that
reinfusion must be accomplished using gravity means, whereby
the bag is suspended in the vicinity of the patient and
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gravity is allowed to drain the collected blood from the bag
for reinfusion to the patient. Unfortunately, the '314
apparatus will not properly drain unless the user first
takes the extra step of bleeding in ambient air into the
blood collection bag prior to reinfusion. This bleeding step
is necessary in order to ford? collected blood inside the
rigid blood collection bag to drain, otherwise the force of
gravity alone will prove insufficient to draw blood from the
bag during reinfusion.
Another example of a blo~~d evacuation system is found
in U.S. Patent No.5,201,703 t~~ Gentelia et al. which
discloses an apparatus for collecting blood from a chest
drainage unit and reinfusion of the blood to the patient.
The '703 patent i~: directed to a self-contained, totally
disposable apparatus comprising an rigid outer container
housing an integrally attached flexible bag for use with a
chest drainage unit. Negative pressure is applied or
maintained inside the interstitial space between the rigid
container and the inner flexible bag for causing blood
stored in the collection chamber to be drawn into the bag.
As drawn blood travels through tubing connecting the '703
apparatus to the chest drainage unit, it begins to fill the
flexible inner back. Once the bag is filled to a desired
level with blood t:he entire apparatus, including the outer
rigid container and the blood-filled inner baq, are
disconnected from the chest drainage unit and suspended from
a suitable suspen~~ion means in the vicinity of a patient for
reinfusion of the collected blood.
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However, a disadvantage with the '703 apparatus is that
the entire apparatus must be employed during reinfusion.
Specifically, both the outer rigid container and the inner
flexible bag are utilized during the reinfusion process
since the '703 apparatus has a unitary design wherein the
inner flexible bag cannot be separated from the outer rigid
container. As a result, another entire apparatus - a
container and evacuation bag - must replace the used
apparatus in order to continue the autotransfusion procedure
on the same patient. Accordingly, the cost to the user is
higher since the entire apparatus must be replaced after
each transfusion.
Another disadvantage to the '703 apparatus is that the
conventional means for attaining higher rates of reinfusion
with the above noted blood evacuation systems are sometimes
not possible. A prior art blood evacuation bag that fixedly
attaches the evacuation bag to the outer rigid container or
is made of a unitary, rigid container design are not adapted
to employ high reinfusion rate techniques. For example, it
is well known in the art that pressure cuffs wrapped around
a flexible blood evacuation bag. can generate higher
reinfusion rates by applying pressure to a bladder of the
pressure cuff surrounding the container. However, if the
evacuation container is of a rigid design a pressure cuff
surrounding the container is unable to exert sufficient
pressure to collapse the inner flexible bag and generate a
higher rate of reinfusion. In view of these disadvantages
regarding cost and performance, it is desirable to have a
blood evacuation system in which only the inner flexible bag
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is used to reinfu~>e blood while the rigid outer container
remains connected to a vacuum source for further collection
T of blood from the chest drainage unit.
Accordingly, a need exists in the art for a blood
evacuation system that permits detachment of the inner
flexible bag from the outer rigid container before
reinfusion so that. another flexible bag may be used inside
the same container in order to collect further blood from
the collection chamber. Moreover, there also exists a need
in the art for a blood evacuation system that provides a
cost effective means of reinfusing blood to a patient using
multiple, detachable evacuation bags to continue blood
evacuation while reinfusion takes place.
DISCLOSURE OF INVENTION
A principle object of the present invention is to
provide a cost-effective means of reinfusing blood to a
patient.
Another object of the present invention is to provide
an efficient method of reinfusing autologous blood to a
patient.
A further object of the present invention is to provide
a blood evacuation system that includes an inner flexible
bag that is separable from its outer container during
reinfusion.
Another further object of the present invention is to
provide a separab7_e evacuation bag that is adapted to
receive a pressure cuff for generating a higher rate of
reinfusion.
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These and other objects of the present invention are
realized in a presently preferred embodiment thereof,
described by way of example and not by way of limitation,
which provides for an apparatus and related method for
evacuating and reinfusing blood to a patient using a blood
evacuation system comprising a separable, flexible inner bag
inside an outer rigid container for reinfusing shed blood
drawn from the collection chamber of a chest drainage unit.
The outer rigid container includes a suction port connected
to a source of vacuum for applying a negative pressure
within the interstitial space between rigid container and
the inner flexible bag disposed therein. The negative
pressure maintained within the interstitial space inside the
container causes blood to be drawn into the bag from the
collection chamber of the chest drainage unit through tubing
which maintains fluid flow communication between the bag and
the collection chamber. Once the bag is filled to a desired
level, the inner flexible bag is removed from the outer
rigid container and suspended within the vicinity of a
patient for reinfusion of the collected blood.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a simplified block diagram showing the blood
evacuation system according to the present invention;
FIG. 2 is a perspective view of the rigid outer
container and transfer tubing according to the present
invention;
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FIG. 3 is a partial cross section view of the rigid
outer container showing the blood evacuation bag according
to the present invention; and
FIG. 4 is a pE=_rspective view of the blood evacuation
bag according to the present invention.
MODE ( S ) FOR CARRYII\fG OUT THE INVENTION
Referring to FIG. 1, a simplified block diagram of an
autotransfusion sy:~tem 11 is illustrated showing the
constituent element=s of system 11. The autotransfusion
system 11 comprise; a patient 10 in fluid flow communication
with a drainage device 12 using transfer tubing 24 to
maintain fluid flow therebetween in direction A. The
autotransfusion system 11 further includes a blood
evacuation system 14 according to the present invention that
is in fluid flow communication with the drainage device 12
using the same type' of transfer tubing 24 used between the
patient 10 and the device 12. Preferably, the transfer
tubing 24 is made of a flexible plastic material, although
any flexible material suitable for transporting fluid, such
as blood, is felt t=o fall within the scope of the present
invention.
Referring to FIGS. 2 and 3, the blood evacuation system
14 according to the present invention is shown. The blood
evacuation system 14 comprises a rigid canister 16 with a
flexible blood evacuation bag 38 disposed therein.
Preferably, the canister 16 has a generally round shape,
although any shaped container suitable for storing fluid is
felt to fall within the scope of the present invention. The
canister 16 includes a lid 18 that is attached to a canister
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body 21 by hinges 34 which permits the lid 18 to swing
freely about the hinges 34 when opening and closing the
canister 16. The canister 16 also includes a labeling area
20 on the outer surface. Preferably, the labeling area 20
includes a surface area for displaying instructions on the
use of the blood evacuation system 14 for the user. The lid
18 of canister 16 has a dome-like shape with a suction port
32 in communication with the interior space 46 inside the
canister 16. The lid 18 further includes a tubing groove 22
along the rim of lid 18 and a spike cover nest 28 formed in
the middle of lid 18 for storing a spike cover (not shown)
therein. The tubing groove 22 provides an opening whereby
the transfer tubing 24 attached to the blood evacuation bag
38 is inserted therethrough and connected to the blood
evacuation bag 38 to establish fluid flow communication with
the collection chamber of drainage device 12. Although the
tubing groove 22 does not maintain a hermetic seal inside
the canister 16, sufficient negative pressure is maintained
inside the interstitial space 50 between the canister 16 and
the blood evacuation bag 28 to generate enough negative
pressure inside the bag 28 for drawing blood into the blood
evacuation bag 38.
The blood evacuation bag 38 disposed inside the
canister 16 has a plurality of ports located at the top
portion of the bag 38. One port, a reinfusion port 42, is
closed and covered with a cap 52 and provides a site for
draining collected blood from the blood evacuation bag 38
after the bag 38 is separated from the canister 16 during
the reinfusion procedure. Another port, a collection port
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40, is provided for attachment to the transfer tubing 24
leading from the drainage device 12 for the evacuation of
blood therefrom.
Referring to FIG. 4, the blood evacuation bag 38 shall
be discussed in greater detail. The blood evacuation bag 38
includes an expandable interi«r space 46 used for the
evacuation of shed blood from the drainage device 12. As
shed blood is collected inside the interior space 46 of the
blood evacuation bag 38, the :pace 46 expands until the bag
38 is filled to the desired lc=vel. A hole 44 located at the
bottom portion of the blood evacuation bag 38 below the
interior space 46 serves as a site for suspending the bag 38
from a suitable suspension me<~ns (not shown) during
reinfusion. A clamp 30 is also provided to prevent fluid
flow through the transfer tub=ing 24 when the user wishes to
stop the flow of blood into the blood evacuation bag 38 and
to also prevent fluid flow from the bag 38 prior to
reinfusion. Preferably, the blood evacuation bag 38
according to the present invention may be manufactured from
any clear, flexible plastic material, although any material
suitable for collecting and reinfusing fluid, like blood, is
felt to fall within the scope of the present invention.
In establishing fluid flow communication between the
blood evacuation bag 38 and tile drainage device 12, a user
engages a spike port (not shown) leading from the collection
chamber of the drainage device 12 with a blood spike 26. The
blood spike 26 is attached to a spike port (not shown)
attached to the distal end of the transfer tubing 24 leading
from the blood evacuation bag 38. Prior to engaging the
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spike port, a dust cover 56 that caps the blood spike 26
during storage and transportation after manufacture is
removed. Once the user engages the blood spike 26 to the
spike port, a source of vacuum is applied to the suction
5 port 32. When vacuum is applied to the inside of canister
16, negative pressure builds inside the interstitial space
50 between the inner surface of canister 16 and the outside
surface of blood evacuation bag 38 inside the canister 16.
With sufficient pressure decrease, blood collected inside
10 the drainage device 12 flows through the transfer tubing 24
and fills the interior space 46 of the blood evacuation bag
38.
Once the blood evacuation bag 38 is filled to a desired
level reinfusion of the blood may take place. The reinfusion
procedure begins by the user applying the clamp 30 to the
transfer tubing 24 and turning off the source of vacuum to
the canister 16, thereby preventing fluid flow therethrough
from the drainage device 12. After the transfer tubing 24 is
clamped, the blood spike 26 is disengaged from the spike
port and properly encapsulated using a spike cover (not
shown) stored inside the nest 2$ of the canister 16 to
protect the contaminated pointed end 31 of the spike 26
after use. After encapsulating the blood spike 26, the lid
18 is opened and the blood evacuation bag 38 is removed from
the canister 16 and suspended in the vicinity of the patient
using suitable suspension means, for example an IV pole.
Once suspended, the user establishes fluid flow
communication between the patient and the blood evacuation
bag 38 by removing the cap 48 from the reinfusion port 42
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and connecting transfer tubing 24 between the patient and
the port 42.
Reinfusion may occur by one of several methods.
Preferably, the blood evacuatuon bag 38 is suspended above
the patient and the shed blood allowed to drain from the bag
38 using the force of gravity alone to draw the blood
through transfer tubing 24 anc~ into patient 10. An
alternative method of reinfus~_on is to apply a pressure cuff
(not shown) around the blood evacuation bag 38 as it is
suspended. As the user applies pressure through a bladder of
the pressure cuff, blood inside the blood evacuation bag 38
is forced out and a higher rage of reinfusion is attained
due to the increased pressure. Preferably, a suspension
means 19 is provided on the outer surface of canister body
21 and includes a :hook integrally formed at the top portion
for suspending the blood evacuation system 14.
Alternatively, a VELCRO support and corresponding VELCRO
loop can be provided at the bottom portion of canister body
21 for suspending the blood evacuation bag 38 from a
suitable suspension means.
While reinfus.ion is occurring, the user may continue
evacuating blood from the drainage device 12 by inserting
another blood evac~sation bag ?.8 into the canister 16 and
reestablishing fluid flow comrtrunication between the bag 38
and the drainage d~=vice 12 as noted above. In this manner,
"batch" autotransfusion takes place by simply replacing the
blood evacuation bag 38 inside the canister 16 every time a
bag 38 is removed for reinfusi.on.
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It should be understood from the foregoing that, while
particular embodiments of the invention have been
illustrated and described, various modifications can be made
thereto without departing from the spirit and scope of the
invention. Therefore, it is not intended that the invention
be limited by the specification; instead, the scope of the
present invention is intended to be limited only by the
appended claims.
