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Urine Collection Problems in the Space Program
Vol. 104, Dec. Printed in U.S.A.
THE JOURNAL OF UROLOGY
Copyright© 1970 by The Williams & Wilkins Co.
URINE COLLECTION PROBLEMS IN THE SPACE PROGRAM JIM L. WALKUP, RUSSELL SCOTT, JR. AND CHARLES A. HOMSY From the Roy and Lillie Cullen Department of Urologic Research, Division of Urology, Baylor College of Medicine, Houston, Texas
The National Aeronautics and Space Administration has expressed an increasing interest in problems of urine collection in space. These problems, of course, are of great interest to urologists. Although further refinements are still in progress, we will outline developments to date. The system currently in use is a cylindrical latex external catheter for drainage which is connected to a collection reservoir within the space suit. This reservoir may be periodically emptied via an external disposal system. Primary potential problems include urine leakage around poor-fitting external collecting devices, bacterial growth and precipitate formation within the stored urine with consequent obstruction of filtering devices and skin irritation from leaked urine. Our research efforts were concerned with developments in 3 specific areas: 1) improved external penile urine collecting device, 2) bacteriostasis and control of precipitation in the stored urine and 3) undergarment for absorption of leaked urine. DEVELOPMENT
OF AN IMPROVED COLLECTING DEVICE
EXTERNAL
Anatomical form-fitting external catheters were fabricated to reduce leakage and improve comfort. These devices were easily produced from polyester resin penile replicas. An impression slurry is prepared by rapidly mixing 80 cc water with 2 standard flat measures of dental impression powder.* The impression slurry is poured into a small paper cup, providing a filled depth of approximately 2 inches for a total cup height of about 5 inches. The urethral meatus is covered with a small tab of adhesive. The subject assumes a position Accepted for publication December 23, 1969. Read at annual meeting of South Central Section, American Urological Association, Colorado Springs, Colorado, October 5-9, 1969. Supported by the National Aeronautics and Space Administration, Contract No. NAS 9-6206, Manned Spacecraft Center, Houston, Texas. * Lange Dental Manufacturing Company, Chicago, Illinois. 898
30 degrees from the vertical and inserts his penis into the slurry~at this stage the slurry presents no resistance to insertion. Approximately 3 minutes after insertion (a total of 4 to 5 minutes after the slurry was prepared) the slurry will set to a firm gel and the penis is removed without discomfort. A plaster of Paris replica of the penis is made using the solidified slurry as a mold (fig. 1, A). The plaster of Paris replicas are then used to develop equivalent molds prepared from silicone rubbert by suspending the plaster of Paris penile replicas within a tapered polyethylene beaker containing the catalyzed rubber (fig. 1, B). The manufacturer's instructions for catalyst addition and de-aeration of the rubber must be followed closely. Curing of the rubber mold is accomplished at room temperature for 48 hours. Temperatures up to 250F may be used for reduced cure times. The silicone rubber molds are then used for casting a polyester resin penile replica. These replicas are produced from hetron 197 polyester resint (fig. 2, A). Two gm. methylethylketone peroxide catalyst was used per 200 gm. of resin.§ The polyester resin cures at room temperature in approximately 12 hours. The surface of the cured replica may be smoothed by gently rubbing with a solvent such as benezene or chloroform. The anatomical, form-fitting devices are then produced from the polyester resin replicas by "dip coating" with a rubber latex solution (fig. 2, B). A blend of 30 per cent nitrile rubber and 70 per cent natural rubber provides better resistance to oxidizing effects of urine than natural rubber alone. A family of forms scaled down in size from a master form may be prepared by producing several beeswax replicas from the master silicone rubber molds (fig. 3). Each beeswax replica may be readily reduced in size by removing sue-
t RTV-634 silicone rubber, General Electric Company, Silicone Products Department, Waterford, New York. t Hooker Chemical Corporation, North Tonawanda, New York. § Lupersol-DDM, Lucidol Division, Wallace and Ternan Corporation, Buffalo, New York.
URINE COLLECTION PROBLENIS IN SPACE PROGRAM
899
circumstance, the best fitting catheter could be selected by trial. The development of a variety of form-fitting external catheters has obvious advantages over the standard cylindrical device of only one size. Indeed, a custom-fitted device may be produced at modest cost for any particular patient and will be of real use to the urologists for use in incontinent patients. BACTERIOSTASIS A:'-ID PRECIPITATION CONTROL
Fm. 1. A, plaster of Paris penile replica made from mold of dental impression plaster. B, silicone rubber molds are prepared by suspending plaster of Paris penile replica in polyethylene beaker filled with catalyzed rubber.
Fm. 2. A, polyester resin penile replica made from silicone rubber molds. B, latex anatomical condom with tubular end for connection to collecting reservoir.
cessive layers of wax with a hot spatula. The scaled forms are then used to produce corresponding silicone rubber molds for production of polyester resin replicas. The resulting set of polyester forms permits the production of a variety of sizes of external catheters of anatomical form. This method of condom fabrication provides for production of either an individually fitted condom or a range of sizes scaled down from a given anatomical configuration. In the latter
The concern of NASA with uncontrolled bacterial growth within the external collection system centers primarily on the potential health hazards to its user and on odor formation. Obstruction of various filtering mechanisms by urine tates also has been indicated as a potential problem. The authors were concerned with finding a simple agent to be added to a system for control of bacterial growth and of precipitate formation. Such an agent might be injected in small quantities to the system after each voiding and might in addition be used in larger quantities to flush the system at intervals. It became apparent that such an agent would have to be non-toxic, potent enough for use in small quantities and biochemically inert. Our initial studies were done using sterile, voided stagnant urine to determine the natural sequence of bacterial growth, precipitate formation and pH changes. Bacterial contamination readily occurs with Proteus and Escherichia coli as the usual predominating organisms. bacterial multiplication occurs, reaching a maximum colony count of approximately 1012 colonies per cc urine at approximately 10 days. Consequent with the bacterial growth, rapid elevation of the urine pH occurs, reaching pH 8.0 as as 48 hours. Alkalinity, once achieved, remains unchanged. Concomitant with bacterial contamination and progressive alkalinization, amounts of precipitates are formed,
Fm. 3. Beeswax penile replica which can be easily made in silicone rubber molds and reduced to produce a variety of sizes.
900
WALKUP, SCOTT AND HOMSY
1. Change in normal urine stored at room temperature
TABLE
Urine 100.0 cc Saline 0.4 cc
Day
pH
Culture
Initial 7
6.0-6.4 8.0
10
8.0
14
8.0
No growth E.coli 3 X 10' Proteus 5 X 1010 E. coli 3 X 1012 Proteus 2.1 X 1012 No growth
23
8. 0
2. Observations made on stored urine when antibacterial solutions are used (2 cc solution per 500 cc urine)
TABLE
Day
pH
Initial 7 10 14
6.0-6.4 6.0-6.4 6. 0-6.4 6.0-6.4 6.0-6.4
23
Culture No No No No No
growth growth growth growth growth
Appearance
Clear Clear Clear Clear Clear, microscopic exam., no sediment
primarily of mold overgrowth, dead bacteria and insoluble calcium and ammonium phosphates (table 1). Accumulation of these precipitates produced marked turbidity quite early. Although a strictly closed stagnant situation is not encountered in the urine collection and drainage system, it is readily appreciated that the aforementioned observations are applicable, as urine is expected to remain in the connection tubing and collection bags which allows ample opportunity for bacterial overgrowth and for formation of precipitates. Our search for a suitable additive agent revealed that a neomycin solution of 400 mg. per 500 cc urine adequately controlled bacterial growth. Greater concentrations did not significantly improve this effect. However, despite adequate bacterial control, progressive alkalinization and precipitation occurred as before. Possible causes of these phenomena are production of significant urease by the surviving bacteria or its accumulation before adequate bacterial control is achieved. Neomycin does not appear to inhibit mycelial growth, which further contributes to a continuing precipitate formation with the use of this agent alone. Attempts have been made to find a suitable agent which might be added to control alkalinity and mold overgrowth. It was found that sodium metabisulfite in small con-
Appearance
Cloudy with precipitate
Foul smell, turbid with precipitate Turbid (4+), microscopic exam. Dead bacteria
centrations adequately maintained urine pH at 6.5 or less when bacterial growth was also sufficiently controlled. Hexadecyltrimethyl ammonium bromide was found to be a potent agent in low concentrations for control of fungal growth. Our studies indicated that control of all parameters for bacterial and mycelial growth, precipitate formation and alkalinity was best achieved by a combination of all 3 agents. Use of 2.0 cc of a solution containing these agents in the following concentrations appeared adequate for control of approximately 500 cc of urine (table 2): 1) hexadecyltrimethyl ammonium bromide, 4 per cent, 0.5 cc; 2) neomycin sulphate, 20 per cent, 0.5 cc and 3) sodium metabisulfite, 40 per cent, 1.0 cc. This solution could be safely used for hospitalized or home-care patients when odor from urine collection bottles is a problem or when urine needs to be collected and stored for biochemical testing or analysis.
Dacron fabric
SUIT Ai SIDE"'
16..BODY If SIDE
---wood pulp and _._,..... Hyd rocol loid
Fm. 4. Urine protection undergarment for rapid absorption and conduction of urine to hydrocolloid.
URINE COLLECTION PROBLE:\IS IN SPACE PROGRAM
URINE PROTECTION UNDERGARMENT
There is need for a garment which may be worn next to the skin to absorb leaked urine in an effort to prevent collection of leaked urine in the genital area with the consequent problem of skin irritation and odor. Developmental work indicates that the most suitable substance may be a fibrous matrix (sawdust) containing granules of hydrocolloid.* This matrix can be surfaced with a nylon fabric on the skin side designed to conduct moisture to the matrix rapidly and in addition feel dry even when wet (fig. 4). The outer or suit side can be covered with a waterproof plastic film to hold moisture in the undergarment and prevent moisture from penetrating into the space suit. Such a garment could be shaped to fit the area of expected leakage with an appropriate hole necessary to accommodate the collection device. It could be designed to absorb up to 300 ml. leaked urine and the fiber of the inner layer could be so constructed that it would absorb and * Personal communication, Johnson & Johnson Laboratory, New Brunswick, New Jersey.
901
conduct the urine away from an area of leakage in a matter of seconds. Further development of this product will prove useful for garments and bedclothing for incontinent patients or patients with urinary fistula. SUMMARY
The National Aeronautics and Space Administration has expressed interest in potential problems of urinary collection in space. Potential problems attendant to the system include urine leakage around poorly fitting external catheters with possible discomfort or skin irritation and bacterial growth in the urine reservoir. A method is described for production of formfitting anatomical external collecting devices made from individual penile replicas. Methods to control bacterial growth, precipitate formation and leaked urine are discussed. Further development with application of these concepts may be beneficial to patients in need of prolonged external catheter drainage because of urinary incontinence or urinary fistulas.
THE JOURNAL OF UROLOGY
Copyright© 1970 by The Williams & Wilkins Co.
URINE COLLECTION PROBLEMS IN THE SPACE PROGRAM JIM L. WALKUP, RUSSELL SCOTT, JR. AND CHARLES A. HOMSY From the Roy and Lillie Cullen Department of Urologic Research, Division of Urology, Baylor College of Medicine, Houston, Texas
The National Aeronautics and Space Administration has expressed an increasing interest in problems of urine collection in space. These problems, of course, are of great interest to urologists. Although further refinements are still in progress, we will outline developments to date. The system currently in use is a cylindrical latex external catheter for drainage which is connected to a collection reservoir within the space suit. This reservoir may be periodically emptied via an external disposal system. Primary potential problems include urine leakage around poor-fitting external collecting devices, bacterial growth and precipitate formation within the stored urine with consequent obstruction of filtering devices and skin irritation from leaked urine. Our research efforts were concerned with developments in 3 specific areas: 1) improved external penile urine collecting device, 2) bacteriostasis and control of precipitation in the stored urine and 3) undergarment for absorption of leaked urine. DEVELOPMENT
OF AN IMPROVED COLLECTING DEVICE
EXTERNAL
Anatomical form-fitting external catheters were fabricated to reduce leakage and improve comfort. These devices were easily produced from polyester resin penile replicas. An impression slurry is prepared by rapidly mixing 80 cc water with 2 standard flat measures of dental impression powder.* The impression slurry is poured into a small paper cup, providing a filled depth of approximately 2 inches for a total cup height of about 5 inches. The urethral meatus is covered with a small tab of adhesive. The subject assumes a position Accepted for publication December 23, 1969. Read at annual meeting of South Central Section, American Urological Association, Colorado Springs, Colorado, October 5-9, 1969. Supported by the National Aeronautics and Space Administration, Contract No. NAS 9-6206, Manned Spacecraft Center, Houston, Texas. * Lange Dental Manufacturing Company, Chicago, Illinois. 898
30 degrees from the vertical and inserts his penis into the slurry~at this stage the slurry presents no resistance to insertion. Approximately 3 minutes after insertion (a total of 4 to 5 minutes after the slurry was prepared) the slurry will set to a firm gel and the penis is removed without discomfort. A plaster of Paris replica of the penis is made using the solidified slurry as a mold (fig. 1, A). The plaster of Paris replicas are then used to develop equivalent molds prepared from silicone rubbert by suspending the plaster of Paris penile replicas within a tapered polyethylene beaker containing the catalyzed rubber (fig. 1, B). The manufacturer's instructions for catalyst addition and de-aeration of the rubber must be followed closely. Curing of the rubber mold is accomplished at room temperature for 48 hours. Temperatures up to 250F may be used for reduced cure times. The silicone rubber molds are then used for casting a polyester resin penile replica. These replicas are produced from hetron 197 polyester resint (fig. 2, A). Two gm. methylethylketone peroxide catalyst was used per 200 gm. of resin.§ The polyester resin cures at room temperature in approximately 12 hours. The surface of the cured replica may be smoothed by gently rubbing with a solvent such as benezene or chloroform. The anatomical, form-fitting devices are then produced from the polyester resin replicas by "dip coating" with a rubber latex solution (fig. 2, B). A blend of 30 per cent nitrile rubber and 70 per cent natural rubber provides better resistance to oxidizing effects of urine than natural rubber alone. A family of forms scaled down in size from a master form may be prepared by producing several beeswax replicas from the master silicone rubber molds (fig. 3). Each beeswax replica may be readily reduced in size by removing sue-
t RTV-634 silicone rubber, General Electric Company, Silicone Products Department, Waterford, New York. t Hooker Chemical Corporation, North Tonawanda, New York. § Lupersol-DDM, Lucidol Division, Wallace and Ternan Corporation, Buffalo, New York.
URINE COLLECTION PROBLENIS IN SPACE PROGRAM
899
circumstance, the best fitting catheter could be selected by trial. The development of a variety of form-fitting external catheters has obvious advantages over the standard cylindrical device of only one size. Indeed, a custom-fitted device may be produced at modest cost for any particular patient and will be of real use to the urologists for use in incontinent patients. BACTERIOSTASIS A:'-ID PRECIPITATION CONTROL
Fm. 1. A, plaster of Paris penile replica made from mold of dental impression plaster. B, silicone rubber molds are prepared by suspending plaster of Paris penile replica in polyethylene beaker filled with catalyzed rubber.
Fm. 2. A, polyester resin penile replica made from silicone rubber molds. B, latex anatomical condom with tubular end for connection to collecting reservoir.
cessive layers of wax with a hot spatula. The scaled forms are then used to produce corresponding silicone rubber molds for production of polyester resin replicas. The resulting set of polyester forms permits the production of a variety of sizes of external catheters of anatomical form. This method of condom fabrication provides for production of either an individually fitted condom or a range of sizes scaled down from a given anatomical configuration. In the latter
The concern of NASA with uncontrolled bacterial growth within the external collection system centers primarily on the potential health hazards to its user and on odor formation. Obstruction of various filtering mechanisms by urine tates also has been indicated as a potential problem. The authors were concerned with finding a simple agent to be added to a system for control of bacterial growth and of precipitate formation. Such an agent might be injected in small quantities to the system after each voiding and might in addition be used in larger quantities to flush the system at intervals. It became apparent that such an agent would have to be non-toxic, potent enough for use in small quantities and biochemically inert. Our initial studies were done using sterile, voided stagnant urine to determine the natural sequence of bacterial growth, precipitate formation and pH changes. Bacterial contamination readily occurs with Proteus and Escherichia coli as the usual predominating organisms. bacterial multiplication occurs, reaching a maximum colony count of approximately 1012 colonies per cc urine at approximately 10 days. Consequent with the bacterial growth, rapid elevation of the urine pH occurs, reaching pH 8.0 as as 48 hours. Alkalinity, once achieved, remains unchanged. Concomitant with bacterial contamination and progressive alkalinization, amounts of precipitates are formed,
Fm. 3. Beeswax penile replica which can be easily made in silicone rubber molds and reduced to produce a variety of sizes.
900
WALKUP, SCOTT AND HOMSY
1. Change in normal urine stored at room temperature
TABLE
Urine 100.0 cc Saline 0.4 cc
Day
pH
Culture
Initial 7
6.0-6.4 8.0
10
8.0
14
8.0
No growth E.coli 3 X 10' Proteus 5 X 1010 E. coli 3 X 1012 Proteus 2.1 X 1012 No growth
23
8. 0
2. Observations made on stored urine when antibacterial solutions are used (2 cc solution per 500 cc urine)
TABLE
Day
pH
Initial 7 10 14
6.0-6.4 6.0-6.4 6. 0-6.4 6.0-6.4 6.0-6.4
23
Culture No No No No No
growth growth growth growth growth
Appearance
Clear Clear Clear Clear Clear, microscopic exam., no sediment
primarily of mold overgrowth, dead bacteria and insoluble calcium and ammonium phosphates (table 1). Accumulation of these precipitates produced marked turbidity quite early. Although a strictly closed stagnant situation is not encountered in the urine collection and drainage system, it is readily appreciated that the aforementioned observations are applicable, as urine is expected to remain in the connection tubing and collection bags which allows ample opportunity for bacterial overgrowth and for formation of precipitates. Our search for a suitable additive agent revealed that a neomycin solution of 400 mg. per 500 cc urine adequately controlled bacterial growth. Greater concentrations did not significantly improve this effect. However, despite adequate bacterial control, progressive alkalinization and precipitation occurred as before. Possible causes of these phenomena are production of significant urease by the surviving bacteria or its accumulation before adequate bacterial control is achieved. Neomycin does not appear to inhibit mycelial growth, which further contributes to a continuing precipitate formation with the use of this agent alone. Attempts have been made to find a suitable agent which might be added to control alkalinity and mold overgrowth. It was found that sodium metabisulfite in small con-
Appearance
Cloudy with precipitate
Foul smell, turbid with precipitate Turbid (4+), microscopic exam. Dead bacteria
centrations adequately maintained urine pH at 6.5 or less when bacterial growth was also sufficiently controlled. Hexadecyltrimethyl ammonium bromide was found to be a potent agent in low concentrations for control of fungal growth. Our studies indicated that control of all parameters for bacterial and mycelial growth, precipitate formation and alkalinity was best achieved by a combination of all 3 agents. Use of 2.0 cc of a solution containing these agents in the following concentrations appeared adequate for control of approximately 500 cc of urine (table 2): 1) hexadecyltrimethyl ammonium bromide, 4 per cent, 0.5 cc; 2) neomycin sulphate, 20 per cent, 0.5 cc and 3) sodium metabisulfite, 40 per cent, 1.0 cc. This solution could be safely used for hospitalized or home-care patients when odor from urine collection bottles is a problem or when urine needs to be collected and stored for biochemical testing or analysis.
Dacron fabric
SUIT Ai SIDE"'
16..BODY If SIDE
---wood pulp and _._,..... Hyd rocol loid
Fm. 4. Urine protection undergarment for rapid absorption and conduction of urine to hydrocolloid.
URINE COLLECTION PROBLE:\IS IN SPACE PROGRAM
URINE PROTECTION UNDERGARMENT
There is need for a garment which may be worn next to the skin to absorb leaked urine in an effort to prevent collection of leaked urine in the genital area with the consequent problem of skin irritation and odor. Developmental work indicates that the most suitable substance may be a fibrous matrix (sawdust) containing granules of hydrocolloid.* This matrix can be surfaced with a nylon fabric on the skin side designed to conduct moisture to the matrix rapidly and in addition feel dry even when wet (fig. 4). The outer or suit side can be covered with a waterproof plastic film to hold moisture in the undergarment and prevent moisture from penetrating into the space suit. Such a garment could be shaped to fit the area of expected leakage with an appropriate hole necessary to accommodate the collection device. It could be designed to absorb up to 300 ml. leaked urine and the fiber of the inner layer could be so constructed that it would absorb and * Personal communication, Johnson & Johnson Laboratory, New Brunswick, New Jersey.
901
conduct the urine away from an area of leakage in a matter of seconds. Further development of this product will prove useful for garments and bedclothing for incontinent patients or patients with urinary fistula. SUMMARY
The National Aeronautics and Space Administration has expressed interest in potential problems of urinary collection in space. Potential problems attendant to the system include urine leakage around poorly fitting external catheters with possible discomfort or skin irritation and bacterial growth in the urine reservoir. A method is described for production of formfitting anatomical external collecting devices made from individual penile replicas. Methods to control bacterial growth, precipitate formation and leaked urine are discussed. Further development with application of these concepts may be beneficial to patients in need of prolonged external catheter drainage because of urinary incontinence or urinary fistulas.