BACKGROUND OF THE INVENTION

The present invention relates to a drainage bag for biological fluids, particularly one suitable for storing urine from a catheterized or ostomy patient.

The urine from a catheterized or ostomy patient is stored in a urinary drainage bag (typically 2000cc capacity) connected by a tubing to one end of a catheter which communicates at its other end with a patient's urinary tract. Typically, the bag is hung on the bed. It includes a removable cap at its bottom for emptying urine at periodic intervals, typically every twelve hours, for durations as long as a number of weeks or more. The bacteria builds up in the warm stale urine remaining in the bag.

It has been found that the bacteria swim in the bag and the tube connected to the catheter. Moreover, on drainage, the bacteria-containing urine typically splashes to cause contamination in the room. This is particularly dangerous when a person is on antibiotics because a resistant strain can be carried to other patients through contamination on the floor and on the health care worker. It has been reported that over ninety percent of the patients who are on catheters and on drainagebags contract severe urinary

tract infections and that approximately 50,000 patients per year die of urinary tract infections. At a minimum, such infections are uncomfortable and costly to the patient.

There is a need for a disposable drainage bag unit, particularly one for collecting urine from a catheterized or ostomy patient, which significantly reduces urinary tract infections.

U.S. Patent 4,700,714 discloses a urine collection device for wearing under clothes for collecting a urine specimen. Contained within the collection device is a dry compressed cellulose sponge for precisely controlling the quantity of urine retained by the bag. The unit specifically is made in a small capacity (up to 23cc) and would not be useful as a drainage bag.

U.S. Patent 4,415,388 discloses particulate absorbents of water-insoluble water-swellable polymer which are immobilized in a liquidpolyhydroxy organic compound. The composition is applied to a surface and the liquid film solidifies. The product is disclosed to provide absorbency to bedpans, sanitary products, diapers, incontinent pads and the like.

U.S. Patent 4,534,767 discloses protective sealing compositions in the form of molded rings or sheets which include a gelled mixture of water-absorbing particulate hydrocolloid gum and non-toxic liquid polyhydroxy alcohol.

Super-absorbent polymers in the form of free-flowing powder have been recently developed which can absorb

hundreds of time their own weight in water. In the soil, the powder becomes a gel which absorbs the water and holds nutrients for plant roots. One suchpolymer is sold by Broadleaf Industries, Inc. of San Diego, California under the trademark P4. It is a high molecular weight, cross-linked polyacrylamide. On absorption, the granules, whichmay be of a sugar-like texture, expand into clear, translucentpieces ofgel, typically ranging from 1/4 to 3/8 inch. There is no suggestion in the literature that such product would be useful for medical applications.

SUMMARY OF THE INVENTION

In accordance with the present invention, a drainage device is provided for collecting biological fluid, such as urine, draining from a catheter connected to a patient. Prior to being filled with the biological fluid, the drainage bag contains free-flowing, water- absorbing, water-swellable, water-insoluble, gel- forming polymer particles. Such particles, preferably cross-linkedpolyacrylamides, are capable of absorbing many times their own weight of water to form expanded gel pieces. The quantity of the particles are sufficient to cause them to be expanded in the drainage bag to form a mass of self-supporting gel pieces substantially throughout the drainage bag. Such gel pieces are capable of substantially immobilizing toxic bacteria present in the drainage bag to prevent substantial movement out of the drainage bag and through the tubing. The drainage bag has a volume capacity of at least lOOcc, typically on the order of 1,000 to 2,000cc for urinary drainage. The bag may also be used for wound drainage.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 illustrates a drainagebag in accordance with the invention attachedto a catheterpriorto filling.

Figure 2 illustrates a drainage bagmostly filledwith biological fluid and showing gel piece formation.

Figure 3 is a cross-section of Figure 2 taken at the line 3-3 illustrating the gel pieces according to the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to Figure 1, a drainage device generally illustrated by the number 10 is illustrated for collecting biological fluid draining from a patient. Drainage device 10 includes a flexible, impermeable drainage bag 11 suitably formed of a conventional transparent flexible plastic material in the shape of a typical ostomy drainage bag including connecting rectangular sidewalls sealed at their adjacent edges to substantially flatten when empty and define an interior chamber 11a upon filling. Bag 11 includes eyes 12 in the top and bottom sealed edges for stringing to an adjustable hanging hook which typically sits on the patient's bed. Bag 11 includes a bacteria air vent 13 near its top edge to permit the bag to breathe and promote drainage. For a catheterized patient, the drainage bag typically is connected subcutaneously to the patient's urinary tract by a conventional catheter 14 suitably in the form of a flexible one-foot long rubber tube having openings 14a communicating with the urinary tract. Only a short stub of the catheter projects from the patient's skin. At the other end of catheter 14 is an enlarged cup 15 forming a female opening suitable

for receiving and retaining male end of tubing connected to the drainage bag for forming a detachable seal.

As illustrated, the catheter connection is formed by a fitting 16 terminating in a rigid plastic finger 16a which is tightly seated within cup 15 to form a fluid seal. Fitting 16 is attached to the distal end of flexible plastic tubing 17 which is either permanently or detachably connected to an inlet port

18 of drainage bag 11 which communicates with interior chamber 11a.

As illustrated, port 18 is detachably coupled to tubing 17. This eliminates breaking the sterile connection with the catheter during bag replacement.

Port 18 includes a relatively rigid connector tube

19 which projects at one end into the interior of chamber 11a and at the other end outwardly from drainage bag 11 for receiving the proximal end of tubing 17 in a detachable sealing engagement. Tubing 17 typically is about two feet long and is formed of a flexible plastic and includes a rigid fitting which detachably locks and seals with the interior of connection tube 19 to form a detachable coupling, by a snap-lock, tapered force-fit, screw-fit, or the like. Connection tube 19 includes a one-way valve passing liquid only in the direction of the bag.

In an alternative embodiment, not shown, the proximal end of tubing 17 is permanently affixed to coupling 19 as by an adhesive or heat welding.

In another alternative embodiment, tubing 17 is connected to the outlet of an ostomy connection, rather than to a catheter.

Drainage bag 11 typically has a capacity of 1,000- 2,000cc or more when used as a urinary drainage bag. Similar configurations can be used for receiving fluids from wound drainage, but the volume of the drainage bag in that instancewouldbe less, but still at least about lOOcc.

Polymer particles 20, preferably in powder form, are disposed in bag drainage 11 prior to use. Such particles are free-flowing, water-absorbing, water- swellable, water-insoluble, gel-forming polymer materials. While particles 20 are preferably in a dry sterile form prior to use, they may also be partially dehydrated prior to use. They are capable of absorbing many times their own weight of water to form expanded gel pieces, typically in irregular shapes of 0.1 to 0.3 inch nominal diameter. The quantity of the polymer particles are sufficient to cause them to expand in the drainage bag and form a mass of such self-supporting gel pieces substantially throughout the drainage bag when the bag is filled with biological fluid.

Effective polymers for the present invention are a cross-linked polyacrylamides. As used herein, the term polyacrylamide includes polymers and copolymers of acrylamide. The copolymers include acrylamide- potassium acrylate and acrylamide acrylate. Other polymersmaybeemployedsuchaspotassiumpropenoate- propenamide copolymer andvarious grafted copolymers. It is pre erable that the polymer particles be formed

of a material which is capable of absorbing at least ten times and preferably over 100 to 200 times or more their own weight of water.

A preferred form of polymer for particles 20 is a cross-linked polyacrylamide sold by Broadleaf Industries, Inc. of San Diego, California under the trademark P4. It is a fine flowable powder or granular solid capable of absorbing over 500 times its own weight in water. Moreover, it is inert to bacteria and does not present a viable environment for the growth of such bacteria. This is contrasted with less-preferred cellulose-grafted absorbent polymers or sponges. Using the P4 product, about 5- lOgm, preferably about 7.5gm, provides a suitable final gel piece mass for a standard 2000cc drainage bag.

Other polymers which may be used include cross-linked polyacrylamide copolymers suchas soldunderthe brand name Agrosoke by Grosoke International of Fort Worth, Texas, potassium proteonate-propenamide copolymers such as sold under the name Viterra Plants-gel by Nepera Chemical Co. of Harriman, New York. Starch grafted copolymers can be used, but they are not as desirable as the foregoing polymers since they can biodegrade. It is advantageous for the particles to gel in a time which would permit the substantially complete absorbance of water into gel particles at the time of breaking seal to replace the bag. To assure that the last biological fluid received by the bag is absorbed into the gel pieces, it is preferable for the particles to absorb substantially all of the liquid within one hour, preferably within 20 minutes.

An importantproperty ofthepolymerparticles is that they expand in the presence of the urine to self- supporting granules, substantially preventing continuous liquid paths of bacteria from the mass of gel granules. It has been found that the expanded gel granules are capable of substantially immobilizing bacteria when present in the drainage bag to prevent substantial movement of the toxic bacteria out of the drainage bag and into the biological fluid in the tubing. Such bacteria tend to enter the drainage bag when the seal between the drainage bag and catheter is broken during the course of connecting a new drainagebagafter disposal oftheprior full drainage bag. The seal breakage can occur either at the connection of the tubing to the catheter or thetubing to the drainage bag, depending upon whether the drainage bag is permanently affixed to the tubing as will be described below.

Another advantage of the particles of the present invention is that when they form the mass of self- supporting gel pieces, there is no splashing liquid in the drainage bag at the time of bag replacement. It is well recognized that during replacement, the splash of biological fluid (e.g. urine) is a very dangerous source of contamination, both within the bag and when splashing into the room.

Referring to Figures 2 and 3, the bag of Figure 1 is illustrated mostly filled with biological fluid illustrating gel pieces 20a. The previously flat bag expands into a pillow shape as in a conventional drainage bag, but it is firm, being substantially completely filled with a mass of gel granules 20a.

It is preferable to include a conventional bactericide within the bag.

Use of the drainage device 10 first will be described with respect to the embodiment of Figure 1 in which the tubing 17 is detachably coupled to connector 19. Catheter 14 is implanted into the urinary tract. The bag hangs with tubing 17 in a vertical upright position with the bag below the level of the patient. A valve in the form of a biased clamp 22 on the tubing on the catheter is initially closed. Then, it is opened for drainage of the patient's urine (or other biological fluid) through catheter 14 into bag 11 which contains polymer particles 20. Drainage continues until the bag is filled or the bag is earlier replaced by an empty one. Prior to replacement, clamp 22 is closed and tubing 17 is removed from connector 19. At this time, there is substantially no free-flowing fluid in the drainage bag since substantially all of the biological fluid is retained within the mass of gel particles. Then, the drainage bag is disposed of and another drainage bag is connected to the tubing 17 and the procedure is done again.

In the alternative where tubing 17 is permanently sealed to tubing 17, bag 11 is detached by decoupling the connection between finger 16a and cup 15. In that instance, clamp 22 is clamped at the time of disconnection.