Biomedical subjects

Robert S Pickard

Publications and source records attributed to Robert S Pickard.

8 recordsLinked to original sources

PubMed2006

Successful voiding after trial without catheter is not synonymous with recovery of bladder function after colorectal surgery.

PURPOSE: The need for monitoring postoperative urine output and the possibility of lower urinary tract dysfunction following colorectal surgery necessitates temporary urinary drainage. Current practice assumes recovery of lower urinary tract function to coincide with successful micturition after removal of urethral catheter. The aim of this study was to analyze the recovery of bladder function following colorectal surgery. METHODS: Patients undergoing colorectal operations underwent preoperative and postoperative uroflowmetry and residual urine estimation. All patients were catheterized suprapubically at surgery. Uroflowmetry and postvoid residual volumes were recorded postoperatively until recovery of bladder function was complete. RESULTS: Thirty consecutive patients underwent suprapubic catheterization, 25 of whom completed the study. Seventeen (68 percent) patients were able to pass urine within 72 hours of surgery. Recovery of lower urinary tract function was delayed in patients undergoing rectal vs. colonic resections (median, 6 vs. 3 days, P = 0.0015). Postvoid residual volumes greater than 200 ml were noted in three (20 percent) patients following rectal resections beyond the tenth postoperative day, with complete emptying achieved by six weeks. CONCLUSIONS: Apparent successful micturition following rectal resections does not always indicate recovery of bladder function. The use of suprapubic catheters, in addition to being safe and effective, allows assessment of residual volumes postoperatively and smoothes the path to full recovery of lower urinary tract function.

Aged↗

PubMed2006

Outcome of transurethral prostatectomy for the palliative management of lower urinary tract symptoms in men with prostate cancer.

OBJECTIVE: To investigate the efficacy of palliative transurethral prostatectomy (TURP) for lower urinary tract symptoms (LUTS) in men with prostate cancer. PATIENTS AND METHOD: The surgical outcome of TURP performed in 46 men with prostate cancer was studied. A poor outcome was defined as the development of urinary incontinence, repeat surgery and placement of a long-term catheter (LTC) within 1 year of surgery. A cohort of 47 men who underwent TURP for benign prostatic hyperplasia (BPH) was used as a control population. RESULTS: Initial catheter removal failed in a larger number of cancer patients compared to men with BPH (43% and 10%, respectively, P = 0.0001). Using objective endpoints, 37% (17/46) of cancer patients were defined as having a poor outcome because of repeat surgery, placement of a LTC or urinary incontinence following TURP. These events occurred in only 12% (6/47) of the control cohort (P = 0.004). In multiple regression analysis a good outcome was associated with presentation in acute urinary retention (AUR; P = 0.01) while a poor outcome was associated with surgery in the context of hormone refractory disease (P = 0.004). Requirement for a LTC despite surgery (12/46) was also associated with the absence of AUR at presentation (P = 0.01) and hormone refractory disease (P = 0.01). CONCLUSION: A significant number of men with prostate cancer and LUTS may not derive a good palliative benefit from TURP. Patients with hormone refractory disease in particular are more likely to have poorer outcomes.

Aged↗

PubMed2005

A prospective randomized trial comparing transurethral prostatic resection and clean intermittent self-catheterization in men with chronic urinary retention.

OBJECTIVE: To determine whether a preliminary period of clean intermittent self-catheterization (CISC) before transurethral resection of the prostate (TURP) improves bladder contractility and surgical outcome in men with chronic urinary retention (CUR), and whether pressure-flow studies (PFS) before TURP predict the outcome. PATIENTS AND METHODS: The study was a two-centre, pragmatic and randomized trial. Included were 41 men scheduled for TURP with lower urinary tract symptoms (LUTS), an International Prostate Symptom Score (IPSS) of > 7, benign prostatic enlargement and a persistent postvoid residual urine volume (PVR) of > 300 mL. They had conventional PFS using unphysiological filling. The patients then gave consent and were randomized into two treatment groups; the first had TURP after stabilizing renal function by indwelling catheterization if indicated, and the second was taught CISC. Men in both groups were reviewed at 3 and 6 months after surgery or the start of CISC, by the IPSS, urine culture and assay of plasma creatinine, and upper tract imaging and repeat PFS at 6 months. The primary outcome variables were IPSS, maximum urinary flow rate, voiding and end-filling pressures, and mean PVR; secondary variables included treatment failure, complications and other urodynamic measures. RESULTS: Of the 41 patients, 17 (mean age 67 years, range 52-84) were randomized to immediate TURP and 24 (mean age 69 years, range 55-85) to CISC. There was a significant improvement in IPSS and quality of life at 6 months in both groups (P < 0.001). In the CISC group there was a significant improvement in voiding and end-filling pressures, indicating recovery of bladder function (P < 0.001 for each). Of the 41 men, nine (22%) with voiding pressures of < or = 45 cmH2O had no significant improvement in symptoms or urodynamic variables. Detrusor overactivity was found in 17 (41%) patients, of whom six had upper tract dilatation which resolved after treatment. CONCLUSION: The present results emphasize the usefulness of CISC in ensuring the recovery of bladder function in men with CUR. Measuring the voiding pressure before TURP can predict the surgical outcome. Both CISC and immediate TURP are effective for relieving LUTS and result in a better quality of life. A preliminary period of CISC before TURP for men with CUR and low voiding pressure may be valuable. The presence of upper tract dilatation is associated with high end-void and end-fill bladder pressures, and such men have a good outcome from surgery.

Aged↗

PubMed2005

Are conventional pressure-flow measurements dependent upon filled volume?

OBJECTIVE: To determine, in a prospective study, whether detrusor pressure (p(det.Qmax)) and maximum urinary flow rate (Q(max)) measurements obtained after filling to maximum cystometric capacity (MCC) differ from those obtained with filling restricted to average voided volume (V(void)), as standard protocols for pressure flow studies (PFS) mandate bladder filling until the subject has a strong desire to void, which aids standardization but further divorces the test from real-life experience. PATIENTS AND METHODS: After calculating the appropriate sample size, 84 patients attending for PFS with an adequately completed 3-day frequency-volume chart were recruited. Each underwent two consecutive PFS with filling to MCC and average V(void) in a random order, and measurements of p(det.Qmax) and Q(max) were compared. For men, the agreement for a diagnosis of obstruction between the tests was also assessed. RESULTS: Complete data were obtained from 76 (90%) of the patients, with a mean (range) age of 64 (20-94) years. The mean (sd) difference between MCC and average V(void) was 134 (113) mL (P < 0.01). There were no significant differences between estimates of Q(max), at - 0.1 (3) mL/s (P = 0.75), and of p(det.Qmax), at - 1 (13) cmH(2)O (P = 0.91), obtained within each patient. For men there was 91% agreement (32 of 35) in the classification of obstruction. CONCLUSIONS: Restriction of filling to the average V(void) during PFS allows a closer approximation to normal voiding and results in no clinically relevant change to the value of standard pressure-flow measurements or alters individual classification of obstruction.

Adult↗

PubMed2004

Noninvasive assessment of bladder contractility in men.

PURPOSE: Preoperative assessment of detrusor function by pressure flow study (PFS) improves outcome from prostatectomy but is invasive and uncomfortable for the patient. We report on a large scale validation of a novel noninvasive assessment of detrusor contractility. MATERIALS AND METHODS: A flexible cuff placed around the penis was inflated automatically during voiding until flow interruption. Cuff pressure at interruption (pcuff.int) reflects isovolumetric bladder pressure (pves.isv), a measure of detrusor contractility. For comparison 151 symptomatic men performed the cuff test with simultaneous PFS monitoring. Test/retest agreement was assessed in 91 subjects who performed a cuff test without PFS on 2 occasions. RESULTS: For the 117 (77%) subjects with an acceptable cuff pressure flow trace, Bland Altman analysis showed that pcuff.int overestimated pves.isv by a mean (s.d.) of 16.4 (27.5) cm H2O, predominantly due to the cuff being positioned below the bladder. For test/retest analysis 52 (57%) of the men who were able to attend twice provided acceptable cuff data on both occasions with a mean (s.d.) difference in pcuff.int of -3.3 (32.0) cm H2O, improving to 0.0 (20.3) cm H2O in a subgroup of 39 subjects who voided more than 150 ml. On questionnaire assessment 121 (80%) subjects preferred the cuff test to PFS. CONCLUSIONS: The cuff test gives a valid and reproducible estimate of isovolumetric bladder pressure in a manner acceptable to patients, although test failure and variability of agreement require improvement. The test may be of value in the assessment of urinary symptoms and may aid in patient selection for prostatectomy.

Adult↗

PubMed2003

Assessment of prostatic obstruction: A cuff may be enough.

AIMS: To investigate the use of an inflatable perile cuff to obstruct flow progressively during voiding in order to provide a noninvasive measure of bladder pressure. METHODS: In this study, we explain the observed relationship of flow rate with applied cuff pressure by analogy with a simple physical model. The model comprised a fixed-pressure reservoir (simulating the bladder), a collapsible tube around which a fixed pressure could be applied (simulating the prostatic urethra), connected by rigid conduit to a further collapsible tube around which pressure could be applied (simulating the penile urethra and cuff). Flow was progressively obstructed by incremental increase of pressure applied to the "penile urethra," with the experiment being repeated for a range of fixed pressures applied to the "prostatic urethra." RESULTS: The model reproduced the typical pressure/flow curves recorded during voiding by using penile cuff inflation in normal and obstructed men. CONCLUSIONS: Our data led us to hypothesise that the relationship between cuff pressure and flow rate can be used to deduce bladder pressure during voiding, prostatic opening pressure, and urethral diameter at the flow-controlling zone, three indicators of lower urinary tract function. These measurements may add to the accuracy of diagnosis and quality of care for a large number of men with lower urinary tract symptoms.

Constriction↗

PubMed2003

Inter-observer agreement in the estimation of bladder pressure using a penile cuff.

AIMS: Objective data are useful in quantifying a patient's lower urinary tract symptoms (LUTS). We are investigating the use of an inflatable penile cuff to obstruct flow progressively during voiding, and thereby determine the pressure p(cuff,int) at which flow is interrupted. The aim of this study was to determine the agreement between experienced observers in their estimates of p(cuff,int). METHODS: We recorded 486 cuff inflation cycles during 142 voids from 42 subjects recruited from urology out-patient's and prostate assessment clinics. Each inflation cycle was assessed independently by three experienced observers, a total of 1,458 ratings. According to our standard assessment procedure, the observers (i) indicated whether the inflation should be analyzed, (ii) estimated p(cuff,int) for those inflation cycles judged suitable for analysis, and (iii) discarded measurements that were clearly inconsistent with others from the same voiding cycle. RESULTS: Overall, 689 of the 1,458 ratings (45%) were excluded, with just 4% of all ratings discarded for inconsistency. For 385 of the 486 inflation cycles (79%) there was complete agreement that the cycle should or should not be analyzed. Thereafter, for the 262 inflation cycles analyzed by two or three observers, the overall SD error in measurements of p(cuff,int) was 4.6 cm H(2)O. CONCLUSIONS: We conclude that there is good agreement between experienced observers in their interpretation of data from the cuff test. For practical purposes, there is no need for multiple observers in the clinical application of the cuff method.

Adult↗

PubMed2003

Can bladder outflow obstruction be diagnosed from pressure flow analysis of voiding initiated by involuntary detrusor overactivity?

PURPOSE: We investigated whether a diagnosis of bladder outflow obstruction could be established from pressure flow analysis of a void initiated by involuntary detrusor overactivity. MATERIALS AND METHODS: A total of 79 men with lower urinary tract symptoms were identified prospectively. In each subject 2 sequential pressure flow studies were performed during the same session. Pressure flow data were recorded during a voluntary void and voiding initiated by involuntary detrusor overactivity. Pressure flow parameters were compared using the paired t test and differences in classification according to the International Continence Society nomogram were analyzed using the chi-square test. RESULTS: The maximum flow rate showed no significant difference between voluntary voiding and voiding initiated by involuntary detrusor overactivity. Detrusor pressure at maximum flow showed a slight, statistically significant but not clinically significant increase during voiding initiated by involuntary detrusor overactivity. However, the diagnostic classification remained unchanged in 64 of 79 men (80%). In no case was the diagnosis altered from bladder outflow obstruction to nonobstruction or vice versa when comparing the 2 pressure flow studies. There were significant increases in maximum detrusor pressure and detrusor pressure at the initiation of voiding during voiding initiated by involuntary detrusor overactivity. CONCLUSIONS: This study demonstrates that increased detrusor pressure observed during voiding subsequent to detrusor overactivity does not change the diagnostic classification in 80% of men. The results provide evidence that bladder outflow obstruction can be reliably diagnosed based on pressure flow parameters recorded during voiding initiated by involuntary detrusor overactivity.

Adult↗