Short-and long-term reproducibility of cystometry

Summary We investigated 8 male patients, age 28–51 years, mean 35, with symptoms of bladder neck dysfunction by means of repeated water-cystometry. We made four cystometries with different patient positions and filling rates followed by a further two cystometries after an interval of 8 days. We found no difference in bladder volumes at first sensation and maximal capacity between the different investigations, irrespective of patient position and filling rate. It was concluded that data obtained by water cystometry may be regarded as absolute.     

Relationship between bladder morphology and long-term outcome of treatment in patients with high pressure chronic retention of urine

A group of 32 men undergoing bladder outflow surgery for high pressure chronic retention (HPCR) of urine were studied prospectively. At the time of treatment marked morphological changes in the bladder wall were demonstrated histologically, but after a mean follow-up of 42.9 months residual urine had decreased significantly and renal function had improved or stabilised in 28 patients (84%). Four patients deteriorated but in 3 of these another potential cause for loss of renal function was present. The majority of patients have a good long-term prognosis following treatment for HPCR.     

The outcome of prostatectomy on chronic retention of urine

A total of 68 men with bladder outflow obstruction and chronic retention (residual urine greater than 300 ml.) underwent investigation before and after prostatectomy with medium fill cystometry and natural fill long-term bladder pressure monitoring. Postoperatively, upper tract dilatation (present in 28 men preoperatively) resolved in all but 2 men and serum creatinine levels improved significantly. Irritative and obstructive symptom scores improved postoperatively (p less than 0.00006), although 17% of the men still had significant symptoms. Residual urine volumes decreased and flow rates improved (p less than 0.00006) but 32% of the men still had a residual urine of greater than 200 ml. Urodynamic parameters improved during medium fill cystometry and long-term monitoring. The main risk factors for upper tract dilatation are a pressure increase during bladder filling on conventional cystometry and the frequency of phasic detrusor activity during long-term monitoring, and they decreased postoperatively.     

Long-term monitoring of bladder pressure in chronic retention of urine: the relationship between detrusor activity and upper tract dilatation

We investigated 41 men with chronic retention of urine owing to bladder outflow obstruction by long-term monitoring of bladder pressure and conventional cystometry to determine the relationship between detrusor pressure and upper tract dilatation. We confirmed that high pressures during conventional filling cystometry were common in men with upper tract dilatation. However, important differences were demonstrated between long-term monitoring and conventional cystometry. The pressure increase during the natural filling phase of long-term monitoring was significantly smaller than that during conventional cystometry. Detrusor instability was found in 88 per cent of the men during long-term monitoring but in only 51 per cent during conventional cystometry (p less than 0.001). High frequency unstable detrusor contractions during long-term bladder pressure monitoring were associated significantly with upper tract dilatation (p less than 0.0001) and correlated significantly with impairment of glomerular filtration rate (rs equals -0.7339, p less than 0.001).     

Behavioral monitoring and urine toxicology testing in patients receiving long-term opioid therapy

No study has examined the role of urine toxicology in addition to behavioral monitoring in patients receiving opioid therapy for chronic pain. All patients maintained on chronic opioid therapy by the two senior authors at two university pain management centers were monitored for 3 yr with urine toxicology testing and for behaviors suggestive of inappropriate medication use. We retrospectively extracted demographic information, aberrant drug-taking behaviors, and urine toxicology information from the medical record. For 122 patients maintained on chronic opioid therapy, 43% (n = 53) had a "problem" (either positive urine toxicology or one or more aberrant drug-taking behaviors). Of patients with no behavioral issues, 21% (n = 26) had a positive urine screen for either an illicit drug or a nonprescribed controlled medication. Of patients with a negative urine screen, 14% (n = 17) had one or more behavioral issues. Monitoring both urine toxicology and behavioral issues captured more patients with inappropriate drug-taking behavior than either alone. Requiring a report of behavioral issues and urine toxicology screens for patients receiving chronic opioids creates a more comprehensive monitoring system than either alone. IMPLICATIONS: Monitoring both urine toxicology and aberrant behavior in chronic-pain patients treated with opioids identified more problem patients than by monitoring either alone. The authors recommend routine urine testing on all patients prescribed opioids for noncancer pain and as a required element in all opioid analgesic studies.     

Measurement of voiding pressures on ambulatory monitoring: comparison with conventional cystometry

A series of 20 patients underwent conventional medium fill cystometry (CMG) and ambulatory monitoring during natural bladder filling (AM). The measurement of voiding pressures by the 2 techniques was compared. The maximum subtracted detrusor contraction pressure recorded during CMG (50 +/- 30 cm H2O) was significantly less than that recorded during AM (86 +/- 35 cm H2O). Voiding pressures during natural filling are greater than those observed during conventional urodynamic studies: this finding may have important implications in the definition of bladder outflow obstruction.     

Comparison of C0 and C2 cyclosporine monitoring in long-term renal transplant recipients

Recent data show that monitoring cyclosporine A (CsA) concentrations with 2-hour postdose levels (C2) correlates with the incidence of rejection and graft outcome in de novo renal transplant patients. The purpose of the present work was to evaluate the advantage of C2 monitoring after the first year of kidney transplantation. We studied 161 patients, 96 on CsA-prednisone and 65 on triple therapy (Aza or MMF) who had been transplanted for a mean of 103+/-44 months. Mean serum creatinine (SCr) was 1.65+/-0.69 mg/dL, mean C0 was 174+/-44, and C2 was 667+/-194 ng/mL. Patients were classified according to C2 values: >850 (n=29), between 850 and 450 (n=109), and <450 (n=23) ng/mL. Patients with C2 <450 ng/mL displayed higher SCr values (1.97+/-0.99; 1.59+/-0.51; 1.52+/-0.4 mg/dL; P<.001), received lower CsA doses (172+/-54; 207+/-54; 227+/-56 mg/d, P<.01), showed lower C0 levels (155+/-48; 172+/-41; 199+/-45 ng/mL; P< .001), and included more patients on triple therapy (54.5%; 44%; 17.2%; P<.05). We found weak correlations between C0 and C2 (r=0.37), between C2 and CsA dose (r=0.36), and between C0 and SCr (r=-0.37). Among 117 patients followed up for 1 year with several C0 and C2 measurements, the coefficient of variation of C0 was 17% and of C2 was 21%. Graft functional deterioration occurred in 16 patients independent of the differences among the C2 groups, but 7 recipients (43.7%) had C0 <150 ng/mL and C2/C0 >5. We conclude that C2 in monitoring stable patients needs further evaluation.     

Comparison between tinzaparin and standard heparin for chronic hemodialysis in a Canadian center

BACKGROUND: Low-molecular-weight heparins offer several advantages over standard heparins, but their use for maintenance hemodialysis has been limited in North America because of their higher cost. Our objective was to compare tinzaparin to standard heparin during maintenance hemodialysis over an 8-week period, in regard to the visual aspect of the extracorporeal circuit, filter reuse, bleeding and time for compression of vascular access at the end of hemodialysis session, nursing time devoted to anticoagulation administration, level of satisfaction of patients and nurses, and relative cost. METHODS: Thirty-two chronic hemodialysis adult patients with peripheral accesses were randomly divided into two groups in a cross-over design: tinzaparin for 4 weeks followed by standard heparin for 4 weeks, or vice versa. Hemodialysis was performed thrice weekly over 3.5-4 h using large surface reused filters. Standard heparin was administered as an initial bolus of 50-75 units per kilogram followed by an infusion to maintain an activated clotting time (ACTESTER) between 150 and 200 s and discontinued 30-45 min before the end of the session. The initial dose of tinzaparin was 3,500 IU anti-Xa for patients usually receiving 7,500 units or less of standard heparin, or 4,500 IU anti-Xa for patients receiving more than 7,500 units of standard heparin, and it was injected as a bolus in the arterial line at the beginning of hemodialysis. Dosage adjustments were made by increments or decrements of 500 IU. RESULTS: A total of 6 patients did not require any adjustment in their dose of tinzaparin and remained at the initial dose, while the remaining 26 necessitated adjustments of the initial dose of tinzaparin: 20 patients required increments from the initial dose whereas 6 required reductions. For most patients, 27 of them, the standard heparin dose was kept at the same level throughout the study period (since it was their usual regimen and they were in stable medical conditions). According to the monitoring scale, the visual aspects of the tubing of the extracorporeal circuit and of the dialyzers at the end of the session were similar for both tinzaparin and standard heparin. The time of compression of the vascular access at the end of the hemodialysis sessions was not significantly different with tinzaparin than with standard heparin. However, as indicated below, most patients noted less bleeding (or oozing) from their access (during compression and thereafter, in the few hours after hemodialysis) with tinzaparin than with standard heparin. Clotting was observed more frequently in the arterial and venous bubble traps with tinzaparin than with standard heparin. The presence of clot(s) was observed in the arterial and venous bubble traps in, respectively, 18 +/- 12 and 10 +/- 6% of the sessions with tinzaparin, while in, respectively, 3 +/- 4 and 2 +/- 4% of the sessions with standard heparin (p < 0.005). Despite a tendency for a reduced reuse number of the dialyzers, the difference did not reach statistical significance. Among the 30 patients who completed the study, 2 reported excessive bleeding from their vascular access with tinzaparin whereas 8 reported such an excessive bleeding with standard heparin. The level of satisfaction of patients and nurses for tinzaparin was extremely good. The main reasons stated by the patients was reduced bleeding from their access after dialysis. The nurses preferred tinzaparin because of the simplicity and the rapidity of its administration, the lack of monitoring required, and the decreased bleeding/oozing tendency from the vascular access sites. The time spent for anticoagulation during a hemodialysis session was reported as 5 min with standard heparin (if no ACTESTER monitoring), 25-30 min with standard heparin (if ACTESTER monitoring required), and 1 min with tinzaparin. The cost analysis revealed that although tinzaparin is more than six times more expensive than standard heparin, the use of tinzaparin becomes similar to the use of standard heparin (USD 7.33 vs. USD 7.62 Canadian dollars for one hemodialysis session) if ACTESTER monitoring is performed (assuming that 22% of the sessions are routinely monitored and that one ACTESTER device is necessary for 8-10 dialysis stations, as applied in our unit). CONCLUSION: Our experience with tinzaparin was positive: it represents a simple and easy way to offer anticoagulation during maintenance hemodialysis, it seems associated with less postdialysis bleeding, it saves precious nursing time and is widely appreciated by patients and staff.     

Extended voiding cystometry: technique and results of monitoring in patients with suprasacral spinal cord injury

Summary Extended voiding cystometry was performed for 3–10 h at the natural filling rate of 20 patients with complete suprasacral spinal cord injury and detrusor hyperreflexia and vesicosphicter dyssynergia who had normal upper tracts. This technique provided documentation of the frequency, duration, and amplitude of and the change in the intercontraction pressure during multiple physiologic voiding cycles. The percentage of time occupied by contractile activity and that during which intravesical pressures were >40 cmH₂O were also calculated. The detrusor activity in this patient group has not previously been reported. Although our patients demonstrated frequent (2.1 contractions/h) high-amplitude (56.8 cmH₂O), long (4 min/contraction) contractions and spent substantial time (13.8% of the time monitored) in contractile activity that maintained intravesical pressures of >40 cmH₂O (8.4%), they showed no evidence of upper tract disease. The five patients who underwent outlet procedures because of clinically problematic autonomic dysreflexia demonstrated a statistically significant postoperative decrease in contraction amplitude (P<0.01) and in time during which intravesical pressures were >40 cmH₂O (P<0.05). Extended voided cystometry enabled the measurement of detrusor contractility patterns and resting intravesical pressures that resulted from physiologic filling rates over an extended period, therefore providing considerably more information about detrusor activity than do conventional cystometric techniques.     

Radiotelemetered cystometry in pigs: validation and comparison of natural filling versus diuresis cystometry

PURPOSE: Cystometry has previously been performed in awake animals using vesical and abdominal catheters, and artificial bladder filling. Conventional urodynamic recordings may be obtained in this manner, albeit under nonphysiological and potentially stressful conditions. Therefore, we developed a technique to perform continuous, ambulatory cystometric monitoring in pigs. MATERIALS AND METHODS: A dual pressure radiotelemetry device was surgically implanted in 22 large white pigs. Vesical and abdominal pressures were recorded and validated, subtracted detrusor pressures were derived and natural fill and diuresis cystometry was compared. RESULTS: Continuous recordings were obtained for 1 to 24 hours, and the devices remained in the animals for up to 3 months. There were few complications and incrustation of the intravesical catheter tip occurred but it did not appear to affect recorded pressures. The pressure data were validated by comparison with filling pressures during bladder distention and simultaneous conventional cystometry at the end of the experimental period. Comparison of natural filling and diuresis cystometrograms showed that natural bladder filling results in higher maximum detrusor pressure during voiding (38.1 versus 33.9 cm. H2O, p <0.05), higher detrusor pressure after contractions (42.6 versus 32.2 cm. H2O, p <0.05) and more frequent detection of unstable contractions in pigs with detrusor instability secondary to experimental manipulation of the lower urinary tract (77.8% versus 45.0%, p <0.05). CONCLUSIONS: This technique allows continuous cystometric monitoring in less stressed animals under more physiological conditions for relatively long periods and, thus, allows prolonged assessment of bladder function in pigs in response to pathological and pharmacological manipulations. Nonphysiological rates of bladder filling have been shown to result in detrusor inhibition, which emphasizes the importance of ambulatory cystometry when describing bladder function.     

Mechanism of upper tract dilatation in patients with thick walled bladders, chronic retention of urine and associated hydroureteronephrosis

The mechanism of upper tract dilatation in patients with obstructive uropathy associated with thick walled trabeculated bladders and painless retention of urine has been determined in 9 cases by simultaneous measurement of renal pelvic and bladder pressures under baseline conditions and after administration of different stresses to the urinary tract. Under basal conditions no pelvic pressure increase was observed during detrusor contraction or other alteration of lower urinary tract pressure. However, after the flow in the upper tract was increased by oral water load, intravenous furosemide or direct pelvic perfusion, pelvic pressures were markedly elevated and reflected accurately any change in intravesical pressure. Under such conditions, pelvic pressures frequently exceeded 40 cm. water. These observations provide an explanation for the increasing size of the upper tract and a clarification of the mechanism whereby renal function might gradually deteriorate in these patients.     

Steroid-induced urogenital tract changes and urine retention in laboratory rodents

Since previous literature suggested that estrogen-treated male mice are models for human benign prostatic hypertrophy, a series of studies was designed to examine urine retention and urogenital tract changes in rodents given chronic estradiol-17 beta (E) and dihydrotestosterone (DHT) treatments. In Study 1, intact and castrate male mice received E, DHT or E plus DHT for four weeks via subcutaneous Silastic capsules. Bladder urine volume increased in the groups given E and this effect was not altered by castration, DHT or removal of E capsules two weeks before necropsy. Estrogen treatment also increased mortality. In Study 2, intact male, intact female, adrenalectomized (Adx) male and sham Adx male mice received 16 weeks of steroid treatments. Bladder urine volume increased in all E treated groups regardless of sex or Adx. Hydronephrosis, hydroureter and increased mortality were found in the E treated mice of both sexes. Estrogen induced epithelial changes and edema of the prostate, vas deferens and the utriculus prostaticus. In further studies male rats, hamsters and guinea pigs were given several different dosages of E but no evidence of urine retention or increased mortality was found. Taken together these studies suggest that E-induced urine retention is unique to mice. Although urine retention and hydronephrosis found in the mice were similar to those in humans with BPH, the lesion that results in the urine obstruction is not similar.