- Email: [email protected]
Differential Uroflometry
r THE JOURNAL OF UROLOGY
Vol. 79, No. 3, March 1958 Printed in U.S.A.
DIFFERENTIAL UROFLOMETRY JOHN R. SHIELDS, ROBERT A. BAIRD*
AND
DONALD F. McDONALD
From the Division of Urology, Department of Surgery, University of Washington School of Medicine and the King County Hospital System, Seattle, Wash.
r
The problems of the act of micturition are central to the specialty of urology. Obstructive diseases of the lower urinary tract are among the most prevalent problems encountered by the urologist and the correction of such obstructions among the principal surgical aims of our specialty. Of less frequency but similar importance are the problems of bladder dysfunction, of neurogenic or myogenic origin. These two disease categories often present with similar manifestations: slow, ineffective and hesitant urination, with incomplete emptying and the sequelae of stasis, chronic infection, and upper tract damage. In many cases, physical examination and well established testing procedures will serve to indicate the type and degree of the disorder. However, this is not always the case. Furthermore, many patients, particularly in the older age group, may present themselves with both types of disease. An objective measurement is necessary for critical evaluation of voiding. The determination of the residual urine is a well established measurement of this type. Other means of evaluating the ability of the patient to void have been proposed but have been found lacking in accuracy, are inconvenient for office use, or are otherwise impractical. Recently Kaufman has devised a urine flow meter to measure the actual rate of delivery of urine from the urinary meatus in a quantitative and graphic manner, convenient to use and capable of reproducible results. Measuring as it does the actual rate of delivery of urine, in the usual posture of urination, it is a means of evaluating directly the patient's functional impairment. However, in the process of using this device on a series of patients, it was apparent that an impaired rate of delivery might, in a given patient, be due either to obstructive disease or bladder dysfunction, since normal urination requires both a normally functioning bladder and an adequate outlet. To dissociate these two factors, it is necessary to hold one constant and evaluate the other. This was done in the series reported here by measuring the patient's ability to void through a standard bladder outlet, supplied by inserting a catheter of standard size, and recording the effectiveness of bladder force through such a catheter determined by means of the urine flow rate. This represents the patient's potential ability to void in the absence of obstruction. By comparing the patient's ability to void in the normal manner, without a catheter, with his ability to void through a catheter of standard size, the effect of the obstructive factor on the urine flow rate can be determined. In this way, each factor, the bladder outlet and the bladder force, can be investigated. Read at annual meeting of Western Section of American Urological Association, Seattle, Wash., May 27-30, 1957. * Robert S. Fox Foundation Student Research Fellow. 580
581
DIFFERENTIAL UROFLOMETRY
It is recognized that the force applied to the urine is the sum of detrusor contraction, position, and the abdominal musculature. The forcefulness of the stream as it issues from the meatus is this sum less the resistance afforded by the urethra and its constrictive diseases. Leaning may also result in an improved fhw. METHOD
Patients included in this study were seen with complaints primarily of prostatism, retention, chronic pyuria, and neurologic disorders, demonstrated or suspected. The age range was from 17 to 93; most of the patients were elderly men with prostatic obstruction. After voiding, patients were catheterized for residual in the supine position, this value being recorded. Through the catheter, 250 or 300 cc sterile saline was instilled, following which the patient voided in the standing position, through the catheter, into the uroflometer. A similar amount of saline was reinstilled, the catheter removed and the patient again voided into the uroflometer. The discrepancy between the amount instilled and the amount voided without catheter was recorded as the "residual by difference," and, in most cases, correlated very well with the original residual. Following surgery, the entire procedure was repeated with one variation: postoperatively, the patients were usually wearing indwelling catheters; therefore, there was no initial residual to record. Postoperative records were made within the first week following surgery; there appeared to be little or no change in the values subsequently. The operative results reported here are limited to transurethral resections of the prostate. Measurements of urine flow rate were made with the recording uroflometer, which produces a continuous record on which urine output in milliliters is plotted against time in seconds. The slope of the resulting curve represents the rate of voiding in milliliters per second and can be directly read from the tracing. The 60
so
40
30
20
10
0
0
so 100 150: 200 '. 250: 300 350 400
Fm. 1. Rate of delivery of saline under 50 cm. hydrostatic pressure through standard Foley retention catheters, all with 30 ml. bag inflated. Tracing A: 18F, 13 ml. per second; B, 22F, 15 ml. per second; C, 26F, 18 ml. per second.
582
SHIELDS, BAIRD AND McDONALD
values reported here are rates read from the steepest straight line portion of the tracing of reasonable duration and are recorded to the nearest whole milliliter per second. Since the total quantity voided is readily read from the tracing, the residual by difference is readily computed. Catheters used in this series were principally size 20F straight red rubber catheters, and Fol
An example of the most frequently seen disease entity in the group of patients reported is shown in figure 2. Patient E.R., a 67-year-old man with one episode of acute retention due to benign prostatic hypertrophy, had a residual of 75 ml. and could produce only 1 ml. of urine per second (tracing A) unassisted. Through a size 20 straight rubber catheter he delivered 11 ml. per second, with a residual 60
50
40
30
20
\
\
\
\
\
\
\
I
A
\
I
10
0
\
/\
\/
\
1/
/ /
0
,
. >
50
"
!" ;,:,
100 150
~
~
200: ~
250:
.
0 50 100 150
~
200 '. 250: 300 350
'
"f
400
"",
"
Fm. 2. A: Preoperative tracing without catheter. B: Preoperative tracing with 20F straight rubber catheter. C: Postoperative tracing without catheter. D: Postoperative tracing with 20F straight rubber catheter.
lllFFEREN'I'IAl, UHOFLOJ\IETffY
difference of ~mo ml. Postoperatively, he had no residual, a flow rate witlwut catheter of 16 ml, per second (C) and 16 ml. per second with a catheter of lhe sam0 siz,e and type . The residual difference was zero. A c.omparison of B and J) demonstrate8 that there is an in U1e bladder foree as rnea,mred by the flmy through the standard catheter at ty1·1J different tirn,•co. Thi:-: is frequently seen when patients are placed on couLimimF drainage, a~ this man Yl'as, following a period of chronic ohc.;truetirnL The s,1me finding rn·.cur:" following surgical relief of obstruction. Thi~ o
50
0 50
11 ~
100 150' 200 '. a
250:
60
50
40
0
0 50 100 150' 200; 250: 300
.\ Tracing without catheter. B. Tracing with size 20 ,Yitb01,' rnthetm following iwriocl of dr:1.inngl'. D· Tracing 1Yit.h period of drainagP.
350
':'
400
__,;,,
catheter. C. Tr,1clng 20 Fole:-· c,d hetnr 1
584
SHIELDS, BAIRD AND McDONALD
basis for bladder dysfunction could be demonstrated, but on the basis of this poor potential capacity to void, a limited success from prostatic resection was predicted for this patient. Following transurethral resection, his rates are shown by E and F of figure 4, tracings which show that with and without the catheter he delivered 10 ml. of urine per second, i.e., that the urethra was capable of removing the urine as rapidly as the bladder could expel it. The residual by difference was 40 ml. Postoperatively, acute retention developed, satisfactorily treated by 24 hours of catheter drainage. Cystoscopically, no bladder neck obstruction was present. Another and more obvious cause of poor flow rate postoperatively is inadequate resection of the obstruction. Figure 5 demonstrates tracings made of the urine flow rates of R.L., 84-year-old man with benign prostatic hypertrophy and one episode of acute retention. Tracings A and B represent his function preoperatively and C and D the postoperative tracings. While the residual by difference and
0 50 100 150 '. 200 '.
0 50 100
~
E
150 '. 200 '.
40
30
0
0 50 100
E
150 '. 200 '. 250: 300 350 400
. .. ,.
'!'
...,'. ~
Frn. 4. A and B: Tracings without catheter and with catheter, preoperatively. C and D: Tracings without catheter and with catheter, preoperatively, but following period of continuous drainage. E and F: Tracings without catheter and with catheter, postoperatively.
586
DIFFEHENTIAL UROFLffME'J'HY
60
50
\
I
40
\
\
\
I
30
20
\
\
\
10
I
--
0
\ ,,,-fI\
s/ \
,)/\
I
0 50 100 150
V
200 oco
60
50
0 50 100
r-
"'
150:
60
50
40
30
20
10
0
0 50 100 150' 200; 250: 300 350 400
,,
__,
A and B: tracings without and with catheter. C and D: without with catheter following first transurethral resection. E F: tracings without and with catheter following second transurethraI resection
the rate with the catheter (reflecting drainage effect) were improved, the rate without the catheter was essentially unchanged. A second transurethral resection was after which the residual, and residual by difference, were both near zero., hut still the unassisted flow rate was poor. This was determined to be due to a, urethral which, when dilated, allowed a satisfactory flow. The of the unassisted flow rate to the potential rate of flow, as the flow through the catheter, at times, been of assistance in value of surgery to a given patient. a health, demonstrates this point by the tracings shown in ma.nm "'"'"''"Qc,n,·Q the rate without catheter, and B, the rate ,vith Gin whicb catheter following several weeks of drainage. His ,vas size 18 apparently arrested by orchiectorny and stilbestroI \\-ere those of chronic pyuria, secondary to a residual moderate azotemia (blood urea nitrogen 65 mg. per and a minor, but troublesorne incontinence. Cystoscopy revealed mild to moderate
586
SHIELDS, BAIRD AND McDONALD
10
0
0 50
\1
100
k
150 200 250 300 350 400
f
Fm. 6. A: Tracing without catheter. B: Tracing with size 18 Foley catheter foHowing period of continuous drainage. 60
50
40
30
20
10
0
0 50 100
V'.)
150 '. 200: 250: 300 350 400
...
Fw. 7. A: Tracing with size 18 Foley catheter. B: Tracing without catheter·
bladder neck obstruction, and the tracings show that the bladder emptied as rapidly without the catheter (7 rnl. per second) as with it (8 rnl. per second), indicating that the impairment of function was at the level of bladder function and not significantly obstructive. He was placed on permanent drainage, with reduction of his blood urea nitrogen, improvement of his infection, and avoided surgery, which did not promise him much improvement. Figure 7 demonstrates the tracings made by RS., a 17-year-old boy ,vho had Hirschsprung's disease which had been resected, and hydroureters. He was evaluated by means of catheter flow studies to determine if any obstructive or neurologic disorder of the bladder might be contributing to his hydroureters. His initial residual was less than 10 ml. His cystogram and cystoscopic exan1inations of the bladder neck showed no abnormalities. His flow rate with a size 18F Foley catheter was 11 ml. per second, and without the catheter, 20 ml. per second. Thus, in his instance, the catheter represented an obstruction, compared to the bladder neck. This is the situation in normal circumstances.
tl87
DIFFJ,;RK'\"TLI_L l1H.OFLOMETHY
60
50
40
0
0
50
11
100 150 200 250 300 350 400
<:>
t-,
"' FIG.
8. A: Tracing; wiHwnt catheter. B: Tracing; with size 20 Foley catlwtc,r
ln this case, it indicated the absence of either obstructive disease or deficient bladder force. )uiothcr and different use of the urine fio-11· rate tracing is demonstrated in figure 8, which shmvs the tracings of urine flow rnte ,vithout catheter ) and with size 20 catheter (B) in a 25-year-olcl ,rnman -with two of alleg<~d inability to void. Seven hundred and 1000 mL of mine were draiDcrl fron, the urinary bladder 011 these occasions. ·"'"·"'""'nnv showed 110 alrnormalities: spina bifida oeculta was noted, and the cystometrogrnm 1vas flat, the pressure reaching but 15 ml. of water after 700 ml. were instilled. She was felt to be neurotic and was taking equinil, -WO mg, q.i.cl. She had hccn under term arologicaJ. manageme1J1, for cystinuria. Stopping the equinil did not affect the cystometrogrnrn or her feeling of inability to Yoid. Finally, the mine flow rate tracings shown in figure 8 ·were made, which demonstrated (tracing AJ that after a rnther poor beginning, she could void at a rate of 18--20 ml. per better than her rate ,Yith the catheter. With thit< iuformatiou for she was convinced that her voiding ability wac; adequate and, witb c,nconrag('ment and psychotherapy, overcame the feeling of inability w void. She now is doing well and carries HO appreciable residual. CO'\'CLTJSION
The tracings deserilwd above are repre:sentative examples of those whid1have been seen in the course of observations of urine ftmv rates with and witlwul catheters in a series of urological patients. They appear to demonstrate seyeral foatnres: The flow rate through the catheter eliminates the obstructive -i;ariuble oJ' the disease ,tud provide:,; an indication of the potential rate of 1Yhich the would be if the existing obstruction were remon'd. C)n this it is possible to predict with some assurance ,vhich patient,; ,rnnld lwndil from resection of the obstruction and which would achieYe limited improvement. ·while soml, haYe an mmssititecl (without catheter) rate po,,toperatiyely 1Yhich i~
588
SHIELDS, BAIRD AND McDONALD
better than the preoperative rate with the catheter, this is distinctly uncommon in this series. '1:Vhen the postoperative urine flow rate is not as nrnch i1nproved as anticipated, even though the residual may be improved, this is good evidence that the resection may have been inadequate or that some other factor is intervening, e.g., stricture. The postoperative flow rate is a valid and superior method of checking the adequacy of resection with no more instrumentation than for determination of residual urine. In practice, postoperative flow rates can be checked without catheterization if the patient fills the bladder by natural means. Continuous catheter drainage of the urinary bladder can be demonstrated to improve the potential function of the bladder, as indicated by the rate with catheter, in the case of chronic urinary tract obstruction. Such improvement should not be overlooked in predicting the probable benefit to the patient of removal of obstruction. In this series, this graphic method of demonstrating the nature of the obstruction and the relatively poor urine flow without a catheter was of much benefit in explaining to patients with obstructive uropathy the degree of obobstruction and the desirability of correction. SUMMARY
A method is presented to evaluate separately the effects of obstructive uropathy and poor bladder function in cases of incomplete or slow urination, by means of measurements of urine flow rates. Representative examples are presented and discussed. REFERENCES BALLEKGER, E.G., ELDER, 0. F. AND McDONALD, H.P.: Voiding distance decreases as important early symptom of prostatic obstruction. South. Med. J., 25: 863, 1932. DRAKE, W. M., JR.: The uroflometer: An aid to the study of the lower urinary tract. J. Urol., 59: 650, 1948. DRAKE, W. M., JR.: The uroflometer in the study of bladder neck obstructions. J.A.M.A., 156: 1079, 1954. KAUFMAN, J. J.: Unpublished comments on the uroflometer, University of California Medical Center; Scientific Exhibit, 32nd annual meeting of the Western Section of the American Urological Association.
Vol. 79, No. 3, March 1958 Printed in U.S.A.
DIFFERENTIAL UROFLOMETRY JOHN R. SHIELDS, ROBERT A. BAIRD*
AND
DONALD F. McDONALD
From the Division of Urology, Department of Surgery, University of Washington School of Medicine and the King County Hospital System, Seattle, Wash.
r
The problems of the act of micturition are central to the specialty of urology. Obstructive diseases of the lower urinary tract are among the most prevalent problems encountered by the urologist and the correction of such obstructions among the principal surgical aims of our specialty. Of less frequency but similar importance are the problems of bladder dysfunction, of neurogenic or myogenic origin. These two disease categories often present with similar manifestations: slow, ineffective and hesitant urination, with incomplete emptying and the sequelae of stasis, chronic infection, and upper tract damage. In many cases, physical examination and well established testing procedures will serve to indicate the type and degree of the disorder. However, this is not always the case. Furthermore, many patients, particularly in the older age group, may present themselves with both types of disease. An objective measurement is necessary for critical evaluation of voiding. The determination of the residual urine is a well established measurement of this type. Other means of evaluating the ability of the patient to void have been proposed but have been found lacking in accuracy, are inconvenient for office use, or are otherwise impractical. Recently Kaufman has devised a urine flow meter to measure the actual rate of delivery of urine from the urinary meatus in a quantitative and graphic manner, convenient to use and capable of reproducible results. Measuring as it does the actual rate of delivery of urine, in the usual posture of urination, it is a means of evaluating directly the patient's functional impairment. However, in the process of using this device on a series of patients, it was apparent that an impaired rate of delivery might, in a given patient, be due either to obstructive disease or bladder dysfunction, since normal urination requires both a normally functioning bladder and an adequate outlet. To dissociate these two factors, it is necessary to hold one constant and evaluate the other. This was done in the series reported here by measuring the patient's ability to void through a standard bladder outlet, supplied by inserting a catheter of standard size, and recording the effectiveness of bladder force through such a catheter determined by means of the urine flow rate. This represents the patient's potential ability to void in the absence of obstruction. By comparing the patient's ability to void in the normal manner, without a catheter, with his ability to void through a catheter of standard size, the effect of the obstructive factor on the urine flow rate can be determined. In this way, each factor, the bladder outlet and the bladder force, can be investigated. Read at annual meeting of Western Section of American Urological Association, Seattle, Wash., May 27-30, 1957. * Robert S. Fox Foundation Student Research Fellow. 580
581
DIFFERENTIAL UROFLOMETRY
It is recognized that the force applied to the urine is the sum of detrusor contraction, position, and the abdominal musculature. The forcefulness of the stream as it issues from the meatus is this sum less the resistance afforded by the urethra and its constrictive diseases. Leaning may also result in an improved fhw. METHOD
Patients included in this study were seen with complaints primarily of prostatism, retention, chronic pyuria, and neurologic disorders, demonstrated or suspected. The age range was from 17 to 93; most of the patients were elderly men with prostatic obstruction. After voiding, patients were catheterized for residual in the supine position, this value being recorded. Through the catheter, 250 or 300 cc sterile saline was instilled, following which the patient voided in the standing position, through the catheter, into the uroflometer. A similar amount of saline was reinstilled, the catheter removed and the patient again voided into the uroflometer. The discrepancy between the amount instilled and the amount voided without catheter was recorded as the "residual by difference," and, in most cases, correlated very well with the original residual. Following surgery, the entire procedure was repeated with one variation: postoperatively, the patients were usually wearing indwelling catheters; therefore, there was no initial residual to record. Postoperative records were made within the first week following surgery; there appeared to be little or no change in the values subsequently. The operative results reported here are limited to transurethral resections of the prostate. Measurements of urine flow rate were made with the recording uroflometer, which produces a continuous record on which urine output in milliliters is plotted against time in seconds. The slope of the resulting curve represents the rate of voiding in milliliters per second and can be directly read from the tracing. The 60
so
40
30
20
10
0
0
so 100 150: 200 '. 250: 300 350 400
Fm. 1. Rate of delivery of saline under 50 cm. hydrostatic pressure through standard Foley retention catheters, all with 30 ml. bag inflated. Tracing A: 18F, 13 ml. per second; B, 22F, 15 ml. per second; C, 26F, 18 ml. per second.
582
SHIELDS, BAIRD AND McDONALD
values reported here are rates read from the steepest straight line portion of the tracing of reasonable duration and are recorded to the nearest whole milliliter per second. Since the total quantity voided is readily read from the tracing, the residual by difference is readily computed. Catheters used in this series were principally size 20F straight red rubber catheters, and Fol
An example of the most frequently seen disease entity in the group of patients reported is shown in figure 2. Patient E.R., a 67-year-old man with one episode of acute retention due to benign prostatic hypertrophy, had a residual of 75 ml. and could produce only 1 ml. of urine per second (tracing A) unassisted. Through a size 20 straight rubber catheter he delivered 11 ml. per second, with a residual 60
50
40
30
20
\
\
\
\
\
\
\
I
A
\
I
10
0
\
/\
\/
\
1/
/ /
0
,
. >
50
"
!" ;,:,
100 150
~
~
200: ~
250:
.
0 50 100 150
~
200 '. 250: 300 350
'
"f
400
"",
"
Fm. 2. A: Preoperative tracing without catheter. B: Preoperative tracing with 20F straight rubber catheter. C: Postoperative tracing without catheter. D: Postoperative tracing with 20F straight rubber catheter.
lllFFEREN'I'IAl, UHOFLOJ\IETffY
difference of ~mo ml. Postoperatively, he had no residual, a flow rate witlwut catheter of 16 ml, per second (C) and 16 ml. per second with a catheter of lhe sam0 siz,e and type . The residual difference was zero. A c.omparison of B and J) demonstrate8 that there is an in U1e bladder foree as rnea,mred by the flmy through the standard catheter at ty1·1J different tirn,•co. Thi:-: is frequently seen when patients are placed on couLimimF drainage, a~ this man Yl'as, following a period of chronic ohc.;truetirnL The s,1me finding rn·.cur:" following surgical relief of obstruction. Thi~ o
50
0 50
11 ~
100 150' 200 '. a
250:
60
50
40
0
0 50 100 150' 200; 250: 300
.\ Tracing without catheter. B. Tracing with size 20 ,Yitb01,' rnthetm following iwriocl of dr:1.inngl'. D· Tracing 1Yit.h period of drainagP.
350
':'
400
__,;,,
catheter. C. Tr,1clng 20 Fole:-· c,d hetnr 1
584
SHIELDS, BAIRD AND McDONALD
basis for bladder dysfunction could be demonstrated, but on the basis of this poor potential capacity to void, a limited success from prostatic resection was predicted for this patient. Following transurethral resection, his rates are shown by E and F of figure 4, tracings which show that with and without the catheter he delivered 10 ml. of urine per second, i.e., that the urethra was capable of removing the urine as rapidly as the bladder could expel it. The residual by difference was 40 ml. Postoperatively, acute retention developed, satisfactorily treated by 24 hours of catheter drainage. Cystoscopically, no bladder neck obstruction was present. Another and more obvious cause of poor flow rate postoperatively is inadequate resection of the obstruction. Figure 5 demonstrates tracings made of the urine flow rates of R.L., 84-year-old man with benign prostatic hypertrophy and one episode of acute retention. Tracings A and B represent his function preoperatively and C and D the postoperative tracings. While the residual by difference and
0 50 100 150 '. 200 '.
0 50 100
~
E
150 '. 200 '.
40
30
0
0 50 100
E
150 '. 200 '. 250: 300 350 400
. .. ,.
'!'
...,'. ~
Frn. 4. A and B: Tracings without catheter and with catheter, preoperatively. C and D: Tracings without catheter and with catheter, preoperatively, but following period of continuous drainage. E and F: Tracings without catheter and with catheter, postoperatively.
586
DIFFEHENTIAL UROFLffME'J'HY
60
50
\
I
40
\
\
\
I
30
20
\
\
\
10
I
--
0
\ ,,,-fI\
s/ \
,)/\
I
0 50 100 150
V
200 oco
60
50
0 50 100
r-
"'
150:
60
50
40
30
20
10
0
0 50 100 150' 200; 250: 300 350 400
,,
__,
A and B: tracings without and with catheter. C and D: without with catheter following first transurethral resection. E F: tracings without and with catheter following second transurethraI resection
the rate with the catheter (reflecting drainage effect) were improved, the rate without the catheter was essentially unchanged. A second transurethral resection was after which the residual, and residual by difference, were both near zero., hut still the unassisted flow rate was poor. This was determined to be due to a, urethral which, when dilated, allowed a satisfactory flow. The of the unassisted flow rate to the potential rate of flow, as the flow through the catheter, at times, been of assistance in value of surgery to a given patient. a health, demonstrates this point by the tracings shown in ma.nm "'"'"''"Qc,n,·Q the rate without catheter, and B, the rate ,vith Gin whicb catheter following several weeks of drainage. His ,vas size 18 apparently arrested by orchiectorny and stilbestroI \\-ere those of chronic pyuria, secondary to a residual moderate azotemia (blood urea nitrogen 65 mg. per and a minor, but troublesorne incontinence. Cystoscopy revealed mild to moderate
586
SHIELDS, BAIRD AND McDONALD
10
0
0 50
\1
100
k
150 200 250 300 350 400
f
Fm. 6. A: Tracing without catheter. B: Tracing with size 18 Foley catheter foHowing period of continuous drainage. 60
50
40
30
20
10
0
0 50 100
V'.)
150 '. 200: 250: 300 350 400
...
Fw. 7. A: Tracing with size 18 Foley catheter. B: Tracing without catheter·
bladder neck obstruction, and the tracings show that the bladder emptied as rapidly without the catheter (7 rnl. per second) as with it (8 rnl. per second), indicating that the impairment of function was at the level of bladder function and not significantly obstructive. He was placed on permanent drainage, with reduction of his blood urea nitrogen, improvement of his infection, and avoided surgery, which did not promise him much improvement. Figure 7 demonstrates the tracings made by RS., a 17-year-old boy ,vho had Hirschsprung's disease which had been resected, and hydroureters. He was evaluated by means of catheter flow studies to determine if any obstructive or neurologic disorder of the bladder might be contributing to his hydroureters. His initial residual was less than 10 ml. His cystogram and cystoscopic exan1inations of the bladder neck showed no abnormalities. His flow rate with a size 18F Foley catheter was 11 ml. per second, and without the catheter, 20 ml. per second. Thus, in his instance, the catheter represented an obstruction, compared to the bladder neck. This is the situation in normal circumstances.
tl87
DIFFJ,;RK'\"TLI_L l1H.OFLOMETHY
60
50
40
0
0
50
11
100 150 200 250 300 350 400
<:>
t-,
"' FIG.
8. A: Tracing; wiHwnt catheter. B: Tracing; with size 20 Foley catlwtc,r
ln this case, it indicated the absence of either obstructive disease or deficient bladder force. )uiothcr and different use of the urine fio-11· rate tracing is demonstrated in figure 8, which shmvs the tracings of urine flow rnte ,vithout catheter ) and with size 20 catheter (B) in a 25-year-olcl ,rnman -with two of alleg<~d inability to void. Seven hundred and 1000 mL of mine were draiDcrl fron, the urinary bladder 011 these occasions. ·"'"·"'""'nnv showed 110 alrnormalities: spina bifida oeculta was noted, and the cystometrogrnm 1vas flat, the pressure reaching but 15 ml. of water after 700 ml. were instilled. She was felt to be neurotic and was taking equinil, -WO mg, q.i.cl. She had hccn under term arologicaJ. manageme1J1, for cystinuria. Stopping the equinil did not affect the cystometrogrnrn or her feeling of inability to Yoid. Finally, the mine flow rate tracings shown in figure 8 ·were made, which demonstrated (tracing AJ that after a rnther poor beginning, she could void at a rate of 18--20 ml. per better than her rate ,Yith the catheter. With thit< iuformatiou for she was convinced that her voiding ability wac; adequate and, witb c,nconrag('ment and psychotherapy, overcame the feeling of inability w void. She now is doing well and carries HO appreciable residual. CO'\'CLTJSION
The tracings deserilwd above are repre:sentative examples of those whid1have been seen in the course of observations of urine ftmv rates with and witlwul catheters in a series of urological patients. They appear to demonstrate seyeral foatnres: The flow rate through the catheter eliminates the obstructive -i;ariuble oJ' the disease ,tud provide:,; an indication of the potential rate of 1Yhich the would be if the existing obstruction were remon'd. C)n this it is possible to predict with some assurance ,vhich patient,; ,rnnld lwndil from resection of the obstruction and which would achieYe limited improvement. ·while soml, haYe an mmssititecl (without catheter) rate po,,toperatiyely 1Yhich i~
588
SHIELDS, BAIRD AND McDONALD
better than the preoperative rate with the catheter, this is distinctly uncommon in this series. '1:Vhen the postoperative urine flow rate is not as nrnch i1nproved as anticipated, even though the residual may be improved, this is good evidence that the resection may have been inadequate or that some other factor is intervening, e.g., stricture. The postoperative flow rate is a valid and superior method of checking the adequacy of resection with no more instrumentation than for determination of residual urine. In practice, postoperative flow rates can be checked without catheterization if the patient fills the bladder by natural means. Continuous catheter drainage of the urinary bladder can be demonstrated to improve the potential function of the bladder, as indicated by the rate with catheter, in the case of chronic urinary tract obstruction. Such improvement should not be overlooked in predicting the probable benefit to the patient of removal of obstruction. In this series, this graphic method of demonstrating the nature of the obstruction and the relatively poor urine flow without a catheter was of much benefit in explaining to patients with obstructive uropathy the degree of obobstruction and the desirability of correction. SUMMARY
A method is presented to evaluate separately the effects of obstructive uropathy and poor bladder function in cases of incomplete or slow urination, by means of measurements of urine flow rates. Representative examples are presented and discussed. REFERENCES BALLEKGER, E.G., ELDER, 0. F. AND McDONALD, H.P.: Voiding distance decreases as important early symptom of prostatic obstruction. South. Med. J., 25: 863, 1932. DRAKE, W. M., JR.: The uroflometer: An aid to the study of the lower urinary tract. J. Urol., 59: 650, 1948. DRAKE, W. M., JR.: The uroflometer in the study of bladder neck obstructions. J.A.M.A., 156: 1079, 1954. KAUFMAN, J. J.: Unpublished comments on the uroflometer, University of California Medical Center; Scientific Exhibit, 32nd annual meeting of the Western Section of the American Urological Association.