Biomedical subjects

Roger C L Feneley

Publications and source records attributed to Roger C L Feneley.

4 recordsLinked to original sources

PubMed2006

A clinical assessment of the performance of a sensor to detect crystalline biofilm formation on indwelling bladder catheters.

OBJECTIVES: To test the ability of a sensor developed to signal infection by the organisms that generate the crystalline biofilms that encrust catheters, to give an early warning that encrustation was occurring on patients' catheters, as the care of many patients undergoing long-term bladder catheterization is complicated by the encrustation and blockage of their catheters. PATIENTS AND METHODS: Twenty patients were followed prospectively for the lifetime of one of their catheters. Sensors based on cellulose acetate/bromothymol blue were placed in the urine-collection bags, which were changed as usual at weekly intervals. The bacteriology was assessed and pH determined weekly on urine samples. Photographic records were made of the sensors twice weekly. On removal, each catheter was examined for encrustation and blockage. RESULTS: Proteus mirabilis was not isolated from five patients and in these cases the sensor colour remained golden-yellow to brown. The catheters drained for the scheduled period and showed no signs of encrustation. By contrast, the sensors turned dark blue/black in the urine of all 15 patients infected with P. mirabilis. All these patients' catheters were encrusted and in 12 the catheters blocked. The mean interval between the sensor signalling and the catheter blocking was 12 days. CONCLUSION: The cellulose acetate/bromothymol blue sensors placed in the urine collection bags are capable of signalling infection by P. mirabilis. They also signal the early stages of catheter encrustation and allow catheter replacement in ample time to avoid the clinical crises and emergency referrals caused by catheter blockage.

Biofilms↗

PubMed2006

Factors affecting crystal precipitation from urine in individuals with long-term urinary catheters colonized with urease-positive bacterial species.

Weekly urinalysis was conducted for 12 weeks on a group of 21 long-term catheter users with confirmed catheter encrustation and urinary tract colonization with urease-positive bacteria, in order to explore the cause of considerable variation in the severity of encrustation between sufferers. The rapidity of catheter blockage correlated significantly with the pH above which crystals precipitated from urine (the nucleation pH) but not the pH of the voided urine itself. Linear regression showed the nucleation pH to be significantly predicted by a combination of urinary calcium and magnesium concentrations, with calcium being the more influential variable. Reducing the rate of catheter encrustation could be achieved by lowering the urinary concentration of calcium and magnesium, which may only require catheter users to increase their fluid intake.

Calcium↗

PubMed2006

Prospective study of individuals with long-term urinary catheters colonized with Proteus species.

OBJECTIVES: To characterize the variability in the times catheters take to block with encrustation in patients who have Proteus in their urinary flora, and to identify factors responsible for modulating the rate of catheter encrustation and blockage. PATIENTS AND METHODS: Twenty patients were followed prospectively for > or = 12 weeks, with a bacteriological analysis on weekly urine samples. The pH of the voided urine samples and the pH at which crystals formed in them (the nucleation pH) were determined. Catheters were collected and examined for bacterial biofilm and crystal deposition. RESULTS: The time that catheters took to block was 2-98 days. The mean pH of the urine voided by patients designated as slow encrusters (6.9) was not significantly different (P = 0.237) from that of rapid encrusters (7.2). However, patients whose catheters took longer to block had a significantly higher mean nucleation pH (8.1 vs 7.3, P = 0.002) and significantly higher mean safety margin between their nucleation pH and voided pH (1.17 pH units vs 0.13, P = 0.003). CONCLUSION: The variation in the rate of catheter encrustation between individuals infected with Proteus is a function of the difference between the voided pH and the nucleation pH of their urine. The value of nucleation pH of an individual's urine varies widely, suggesting it should be possible to devise strategies to increase this value and thus reduce the rate of encrustation in those with urinary tract colonization by urease-positive bacteria.

Biofilms↗

PubMed2005

Pelvic floor exercises for erectile dysfunction.

OBJECTIVE: To examine the role of pelvic floor exercises as a way of restoring erectile function in men with erectile dysfunction. PATIENTS AND METHODS: In all, 55 men aged > 20 years who had experienced erectile dysfunction for > or = 6 months were recruited for a randomized controlled study with a cross-over arm. The men were treated with either pelvic floor muscle exercises (taught by a physiotherapist) with biofeedback and lifestyle changes (intervention group) or they were advised on lifestyle changes only (control group). Control patients who did not respond after 3 months were treated with the intervention. All men were given home exercises for a further 3 months. Outcomes were measured using the International Index of Erectile Function (IIEF), anal pressure measurements and independent (blinded) assessments. RESULTS: After 3 months, the erectile function of men in the intervention group was significantly better than in the control group (P < 0.001). Control patients who were given the intervention also significantly improved 3 months later (P < 0.001). After 6 months, blind assessment showed that 40% of men had regained normal erectile function, 35.5% improved but 24.5% failed to improve. CONCLUSION: This study suggests that pelvic floor exercises should be considered as a first-line approach for men seeking long-term resolution of their erectile dysfunction.

Adult↗