Analysis of Factors' Association with Risk of Postoperative Urosepsis in Patients Undergoing Ureteroscopy for Treatment of Stone Disease.

INTRODUCTION: To investigate which patient, stone, infective, and surgical factors were most likely to increase the risk of postoperative urosepsis within 28 days of ureteroscopy (URS) and laser stone fragmentation for ureteral or renal stones. METHODS: Data were collected prospectively in a single National Health Service institution. A logistic regression model was used to assess the association of factors with postoperative urosepsis. Two matched-pair analyses were used to assess the risk of postoperative urosepsis in patients with (a) an emergency presentation to hospital with urosepsis in the 90 days preceding URS and (b) a positive midstream sample of urine (MSSU) identified, but who were asymptomatic at preoperative assessment, who then received an appropriate course of antibiotics. RESULTS: Four hundred sixty-two consecutive patients were included in the study. Thirty-four patients (7.4%) had an episode of urosepsis within 28 days of their operation. A positive preoperative MSSU was significantly associated with postoperative urosepsis on multivariable analysis, despite appropriate treatment with a preoperative course of antibiotics: odds ratio (OR) 4.88, 95% confidence interval (CI) 2.11, 11.31, p < 0.001. The presence of diabetes mellitus, presence of ischemic heart disease, patient American Society of Anesthesiologists score, same-session bilateral URS, and stone volume were the other variables significantly associated with postoperative infection on univariable analysis, but these ceased to be significantly associated on multivariable analysis. Subgroup analysis found that a positive MSSU in both patients with a preoperative ureteral stent and those without was significantly associated with postoperative urosepsis, however, the OR was much lower for the stented group (OR 3.23 vs OR 16.67). On matched-pair analysis, patients with a positive preoperative MSSU were significantly more likely to have postoperative urosepsis compared to controls (OR 17.46, 95% CI 2.18, 139.80, p = 0.007). There was no significant difference in the OR of postoperative urosepsis in patients who had a preceding urine infection requiring hospital admission in the 90 days preceding URS (OR 0.60, 95% CI 0.19, 1.92, p = 0.39). CONCLUSIONS: Positive preoperative MSSU was significantly associated with postoperative urosepsis by logistic regression and matched-pair analysis. These higher risk patients should be counseled appropriately before surgery, and should be the focus of vigilant postoperative monitoring. The study suggests particular caution in patients with a positive preoperative MSSU without a preoperative ureteral stent.

Maximum urethral closure pressure in women: normative data and evaluation as a diagnostic test.

INTRODUCTION AND HYPOTHESIS: Our goal was to identify correlates of maximum urethral closure pressure (MUCP) and MUCP as a diagnostic test for stress urinary incontinence (SUI). METHODS: This study was a retrospective review of women with non-neurological referrals for urinary incontinence between1995 and 2006. RESULTS: We studied the characteristics of 8,644 women who underwent urodynamics for non-neurological referrals. Mean MUCP was 48 cm H(2)O in urodynamic stress incontinence (USI), 50 cm H(2)O in mixed urinary incontinence (MUI), 65 cm H(2)O in detrusor overactivity incontinence (DOI) and 67 cm H(2)O for continent women . Age and MUCP were negatively correlated in all groups. Multiple regression analysis showed lower levels of MUCP in women with USI who also had previous hysterectomy or anti-incontinence surgery or who were in an older age group. Previous anti-incontinence surgery and older age were risk factors for lower MUCP in women with MUI and DOI. Receiver operator curves did not show MUCP to have utility as a diagnostic test despite age and parity stratification. MUCP < 20 cm H(2)O showed a sensitivity of 5 % and specificity of 98 % in diagnosing USI. CONCLUSIONS: MUCP failed to meet the criteria for a diagnostic test. Women with USI and MUI have lower MUCP than women with DOI and continent women in each decade of life. MUCP decreases with age.

Strategy to control catheter encrustation with citrated drinks: a randomized crossover study.

PURPOSE: Nucleation pH is the pH at which Ca and Mg come out of urine to form crystals. If the safety margin between voiding pH and nucleation pH could be increased, it would increase the possibility of an alternative to controlling the activity of urease producing bacteria as a strategy to control catheter encrustation. MATERIALS AND METHODS: We performed a 6-week randomized crossover study in 24 patients with catheter blockage who were randomly allocated to a specific sequence of 3 consecutive available treatments, including increased fluid intake, lemon juice and potassium citrate. Each patient received all available regimens. At the end of each week 24-hour urine samples were analyzed for voiding and nucleation pH, citrate, Ca and Mg. RESULTS: Mean +/- SD nucleation pH increased from 7.45 +/- 0.60 at baseline to 7.93 +/- 0.50, 7.68 +/- 0.64 and 7.96 +/- 0.37 in the lemon juice, increased fluid intake and potassium citrate groups, respectively (p <0.0001). Mean urinary citrate increased significantly (p <0.0001), in particular due to lemon juice and potassium citrate effects. The association between treatment and Ca was weak (p = 0.12) while that of Mg was negative due to lemon (p <0.001). Average increase in the safety margin (nucleation pH minus voiding pH) beyond baseline was 0.84 (95% CI 0.63-1.04), 0.57 (95% CI 0.37-0.78) and 0.41 (95% CI 0.20-0.61) for lemon juice, increased fluid intake and potassium citrate, respectively. A strong treatment effect on the safety margin was apparent even when controlling for study design (p <0.001). CONCLUSIONS: Increased fluid intake with lemon juice may be a simple, inexpensive, effective strategy to control catheter encrustation.

Using bladder ultrasound to detect urinary retention in patients.

Bladder ultrasound is now considered a safer alternative to catheterisation in the diagnosis of urinary retention. This article outlines how bladder ultrasound works and its practical uses.

The use of ultrasound-estimated bladder weight in diagnosing bladder outlet obstruction and detrusor overactivity in men with lower urinary tract symptoms.

OBJECTIVES: Measurement of bladder weight using ultrasound estimates of bladder wall thickness and bladder volume is an emerging clinical measurement technique that may have a role in the diagnosis of lower urinary tract dysfunction. We have reviewed available literature on this technique to assess current clinical status. METHODS: A systematic literature search was carried out within PubMed and MedLine to identify relevant publications. These were then screened for relevance. Preliminary results from our clinical experiments using the technique are also included. RESULTS: We identified 17 published papers concerning the technique which covered clinical studies relating ultrasound-estimated bladder wall thickness to urodynamic diagnosis in men, women, and children together with change in response to treatment of bladder outlet obstruction. The original manual technique has been challenged by a commercially available automated technique. CONCLUSION: Ultrasound-estimated bladder weight is a promising non-invasive technique for the categorization of storage and voiding disorders in both men and women. Further studies are needed to validate the technique and assess accuracy of diagnosis.

Could the National Institute for Health and Clinical Excellence guidelines on urodynamics in urinary incontinence put some women at risk of a bad outcome from stress incontinence surgery?

OBJECTIVE: To evaluate the potential impact of the UK National Institute for Health and Clinical Excellence (NICE) recommendation that preoperative urodynamics are not necessary for women with 'pure symptoms of stress urinary incontinence' (SUI), by using data from a population of women referred with lower urinary tract symptoms. PATIENTS AND METHODS: In a retrospective study of 6276 women with UI, from an electronic database at a tertiary referral centre, information was collected and entered into a urodynamics computer database at the time of history taking and before conducting the tests. The database was used to identify women aged 18-80 years who had multichannel cystometry for UI over a 17-year period (1 January 1990 to 31 December 2006). To apply the NICE criterion of a 'clearly defined clinical diagnosis of pure SUI', strict selection criteria were used to identify patients with pure SUI. The reliability of the patients' history in predicting 'pure' urodynamic SUI in patients with 'pure' SUI was investigated. The correspondence of the symptomatic diagnosis of pure SUI with the urodynamic findings was assessed, and sensitivity, specificity, positive and negative predictive values were calculated using contingency tables. RESULTS: Only 324 (5.2%) women had pure SUI; moreover, a quarter of those with pure SUI symptoms ultimately had urodynamic diagnoses other than urodynamic SUI, that could affect the outcome of continence surgery. CONCLUSION: These findings indicate that only a small group of women fulfil the NICE criteria of pure SUI. These strict criteria do not ensure that all women with potentially important urodynamic findings are evaluated accordingly. Therefore, we suggest that this NICE recommendation was unwise and, furthermore, was not based on properly acquired expert opinion.

Persistent detrusor overactivity after transurethral resection of the prostate.

Detrusor overactivity is associated with aging and benign prostatic obstruction and often causes the troublesome symptoms of urgency and urgency incontinence (overactive bladder), persistent detrusor overactivity after transurethral resection of the prostate being the cause of more than a third of poor symptomatic outcomes following surgery. Most of the evidence currently suggests that neurons of the urothelium at the bladder neck play a significant role in the genesis of detrusor overactivity. Treatment options including botulinum toxin injections and intravesical vanilloids have been studied in the treatment of persistent detrusor overactivity, but further studies are needed specifically in patients with persistent detrusor overactivity after transurethral resection of the prostate. As urodynamic studies are able to predict a proportion of postoperative failures, more widespread use is advocated by many in the routine assessment of lower urinary tract symptoms thought to be due to benign prostatic obstruction.