Accuracy of urinary dipstick testing for pH manipulation therapy.

PURPOSE: To determine the accuracy of urinary dipstick testing for pH manipulation therapy. MATERIALS AND METHODS: Three commercial brands of dipstick paper were used to measure the pH of 100 fresh urine specimens from patients with urologic diseases. These were all read by an experienced medical technician. The pH of these specimens was also measured with an electrochemical pH meter ("gold standard") performed by another experienced technician. Both were blinded to each other's results. The influence of urinary microscopic findings was also assessed. Student t test and analysis of variance were used to analyze the data. RESULTS: The accuracies of the dipsticks for determining pH were as follows: 54.8% to 92.8% for less than 6, 45% to 97.5% for 6 to 7, 72.2% to 83.3% for greater than 7. One of the dipsticks assessed had the lowest accuracy for all three ranges. There was a statistically significant difference between the performances of the other two as compared with the least accurate one. There were no statistically significant differences between the two more accurate dipsticks. Urinary microscopic findings and other dipstick results did not influence results. CONCLUSION: The targeted pH range for urinary pH manipulation therapy is 6 to 7. These results indicate that dipstick testing may be applicable to monitor patients on pH manipulation therapy and modify treatment when necessary. The accuracy of the device used for this purpose, however, must be determined before use.

Role of laparoscopic stone surgery.

OBJECTIVES: To define the role of laparoscopic stone surgery in current urologic practice. METHODS: All cases of laparoscopic surgery for renal calculus disease performed at a single institution during a 2-year period were reviewed. A total of 449 stone-removing procedures were performed by one of us (D.G.A.) during this interval, of which 5 were laparoscopic (1.1%). Of the five laparoscopic procedures, three were pyelolithotomy/pyeloplasty, one was laparoscopic-assisted percutaneous nephrostolithotomy, and one was caliceal diverticular stone removal. RESULTS: All 5 patients were rendered stone free, and no patient had perioperative complications. CONCLUSIONS: A laparoscopic approach is rarely needed in patients requiring stone removal. However, it can be a safe and effective approach in the management of select patients with complex stone disease.

Management of cystinuria.

Cystinuria is a monogenic disorder in which there is a transepithelial transport defect of di-basic amino acids, including cystine, ornithine, lysine, and arginine (COLA). This results in diminished reabsorption of these amino acids in both the intestine and renal proximal tubule. This article describes the disorder, reviews the mechanisms of normal COLA renal transport, and summarizes issues related to the disorder, such as the role of mutations, associated diseases, clinical manifestations, therapies, the renal impact, and handling of pediatric patients.

Current opinion in urology: new insights into nephrolithiasis.

PURPOSE OF REVIEW: Recent studies in nephrolithiasis have investigated why stones form, improvements in medical therapy, and advances in surgical therapy. We outline recent research in these areas. RECENT FINDINGS: We describe a series of articles characterizing the histopathology of Randall's plaques and the renal papillae in patients with nephrolithiasis, detailing genetic discoveries related to uric acid stones, describing further uses of alpha-antagonists in nephrolithiasis, and reporting improvements in extracorporeal shockwave lithotripsy technique and outcomes. SUMMARY: Characterization of the renal papillae and Randall's plaques in different types of stones may guide the urologist in treating stones and may lead to further research into how and where stones of different compositions form.