Preventing the forgotten ureteral stent: implementation of a web-based stent registry with automatic recall application.

OBJECTIVES: To describe and analyze a unique computerized system that tracks ureteral stents and automatically sends a notice by e-mail to clinical staff if a stent becomes overdue for removal. METHODS: We have developed an electronic stent register (ESR) and stent extraction reminder facility (SERF) located within our hospital computer network. After stent insertion, a stent "episode" is created in the ESR with a mandatory maximal stent life (MSL). The SERF interrogates the ESR on a daily basis and identifies stents that have breached its MSL, generating daily e-mail notices to personnel until the stent is removed and the ESR updated. The episode data capture initially employing manual entry was changed to barcode technology acquisition. We analyzed the success of patient recall and conducted a prospective, blinded review to determine the success of the data acquisition. RESULTS: A total of 293 episodes were created within 2.4 years. Of the 241 (86%) episodes that were closed, 123 (51%) went beyond the MSL. The mean delay from designated MSL to stent removal was 20.89 days (SD 19.71). In the 7 months before barcode data acquisition, 43 of 71 stents were entered into the ESR (data capture rate 61%). In the 7 months after barcode data acquisition, 52 of 60 stents were entered (data capture rate 87%; P = 0.0009). CONCLUSIONS: The results of our study have shown the ESR and SERF to be robust and valuable tools for the treatment of patients with ureteral stents. Barcode acquisition significantly improved the stent insertion capture rate. This system ensures improved patient safety with an element of protection from potential litigation.

Size matters: a survey of how urinary-tract stones are measured in the UK.

BACKGROUND AND PURPOSE: Stone size forms the basis of management pathways in patients with urolithiasis. We carried out a questionnaire-based audit to find out how stone size is routinely measured by radiologists in the UK. MATERIALS AND METHODS: A series of 831 anonymous questionnaires concerning how stone size is assessed using four imaging modalities--plain abdominal radiograph (KUB film), intravenous urogram (IVU), ultrasound, and CT--were sent to 277 radiology departments. Following the survey, a substudy at our institution compared urologists (N = 10) and radiologists (N = 5) in estimating the size of a large (26-mm) and small (11- mm) calculus on KUB films. RESULTS: Of the questionnaires, 425 were returned, and 421 were analyzed. Of these, 85% were from consultants, 14% from trainees/middle grades, and 1% "unspecified." In total, 92% of the respondents were radiologists (10% uroradiologists) and 8% urologists. Estimation of stone size ("guestimation") from KUB films and IVUs was used by 40% and 36% of radiologists, respectively, whereas graded rulers were used by 57% and 59%, respectively. For ultrasound scans and CT, electronic measurement was the favored method (81% and 73%), but guestimation was still used by 10% and 15%, respectively. When assessing the KUB films and IVU, 59% and 61% of urologists, respectively, also used guestimation. The substudy revealed a significant difference among radiologists in the accuracy of size estimation for the 11-mm stone (mean estimated size 9.6 mm; P = 0.02, one-sample t-test). CONCLUSION: A large proportion of radiologists use guestimation for assessing stone size on KUB films and IVU. Even when electronic measuring aids were available for CT and ultrasonography, guestimates remained prevalent. Our substudy showed that radiologists significantly underestimated the smaller stone.

Calcium urolithiasis, blood pressure and salt intake.

OBJECTIVES: To determine whether stone-formers have higher BP than controls drawn from the general population and matched for age, sex and ethnic origin and to compare the relationship between sodium and calcium excretion in the two groups. PATIENTS AND METHODS: Thirty-six patients [mean (+/-standard deviation, SD) = 49.0 +/- 11.7 years; range 27-70 years] with kidney or ureteric stones and 108 controls (mean age of 49.6 +/- 6.8 years; range 39-61 years), matched for gender, ethnic origin and age group were studied. Patients and controls underwent physical measurements, a venous blood sample and they were asked to collect a 24-h urine sample for sodium, potassium, calcium and creatinine. RESULTS: Stone-formers were significantly heavier and had higher BP than age-, sex- and ethnic-matched population controls. Whilst the difference in systolic BP was independent of the difference in body mass index [16.8 mmHg (7.2-26.4 mmHg), p = 0.001), the difference in diastolic BP was attenuated after adjustment for body mass [1.8 (-3.4 to 7.1), p = 0.49]. Stone-formers passed less urine than controls [-438 ml/day (95% CI -852 to -25), p = 0.038]. They had higher urinary calcium than controls [+3.7 mmol/day (2.8-4.6 mmol/day), p < 0.001], even when expressed as ratio to creatinine [+0.20 (0.11-0.29), p < 0.001]. Sodium excretion was positively associated with urinary calcium in both stone-formers and in controls. The slopes were comparable (0.92 vs 0.98 mmol Ca/100 mmol Na) so that for any level of sodium excretion (or salt intake), stone-formers had a higher calcium excretion than controls. CONCLUSIONS: In stone-formers, the BP is higher than in controls. Stone-formers excrete more calcium than controls do. In stone-formers and controls, the relationship between urinary sodium and calcium is similar. Since this relationship results from an effect of sodium on calcium, a reduction in salt intake may be a useful method of reducing urinary calcium excretion in stone-formers. However, the "relative" hypercalciuria seen in stone-formers is independent of salt intake and may well reflect an underlying genetic predisposition.