I searched Medline to identify recent articles (1990-2003) related to the evaluation and management of kidney stones. Key words used included kidney stones, urinary calculi, urolithiasis, urinary tract stones, and nephrolithiasis.

Sources and search criteria I searched Medline to identify recent articles (1992- 2001) related to the management of chronic renal disease and its complications. Key words used included chronic kidney disease, chronic renal failure, kidney disease, end stage renal disease, anaemia, erythropoietin, ischaemic heart disease, cardiac disease, lipid disorders, hyperparathyroidism, calcium, phosphate, nutrition, diabetes, and hypertension in relation to kidney disease. I also referred to the recent clinical practice guidelines published by the National Kidney Foundation.2

Background: Small randomized trials demonstrated that a lower compared with higher dialysate temperature reduced the average drop in intradialytic blood pressure. Some observational studies demonstrated that a lower compared with higher dialysate temperature was associated with a lower risk of all-cause mortality and cardiovascular mortality. There is now the need for a large randomized trial that compares the effect of a low vs high dialysate temperature on major cardiovascular outcomes. Objective: The purpose of this study is to test the effect of outpatient hemodialysis centers randomized to (1) a personalized temperature-reduced dialysate protocol or (2) a standard-temperature dialysate protocol for 4 years on cardiovascular-related death and hospitalizations. Design: The design of the study is a pragmatic, registry-based, open-label, cluster randomized controlled trial. Setting: Hemodialysis centers in Ontario, Canada, were randomized on February 1, 2017, for a trial start date of April 3, 2017, and end date of March 31, 2021. Participants: In total, 84 hemodialysis centers will care for approximately 15 500 patients and provide over 4 million dialysis sessions over a 4-year follow-up. Intervention: Hemodialysis centers were randomized (1:1) to provide (1) a personalized temperature-reduced dialysate protocol or (2) a standard-temperature dialysate protocol of 36.5°C. For the personalized protocol, nurses set the dialysate temperature between 0.5°C and 0.9°C below the patient’s predialysis body temperature for each dialysis session, to a minimum dialysate temperature of 35.5°C. Primary outcome: A composite of cardiovascular-related death or major cardiovascular-related hospitalization (a hospital admission with myocardial infarction, congestive heart failure, or ischemic stroke) captured in Ontario health care administrative databases. Planned primary analysis: The primary analysis will follow an intent-to-treat approach. The hazard ratio of time-to-first event will be estimated from a Cox model. Within-center correlation will be considered using a robust sandwich estimator. Observation time will be censored on the trial end date or when patients die from a noncardiovascular event. Trial Registration: www.clinicaltrials.gov ; identifier: NCT02628366.

Objective: Hypokalemia and renal potassium (K) wasting are hallmarks of the group of disorders called Bartter’s syndrome. The presence of hypomagnesemia and a low rate of excretion of calcium are currently used to characterize a subgroup of these patients as having Gitelman’s syndrome (GS) in which the molecular lesion is a defect in the thiazide-sensitive NaCl cotransporter in the distal convoluted tubule. This study was undertaken to examine whether bicarbonaturia or hypomagnesemia exacerbates the kaliuresis in patients with GS. Methods: Six patients with most of the diagnostic features of GS were examined. To examine the role of bicarbonaturia, the transtubular K concentration gradient (TTKG) was assessed before and after an oral load of NH₄Cl which caused the urine pH to be <6. To evaluate the role of hypomagnesemia, the TTKG was examined after an infusion of enough magnesium (Mg) to achieve normal levels of Mg in plasma for close to 24 h. Results: The TTKG remained very high even when the pH of the urine was <6.0. An infusion of Mg caused the TTKG to approach expected values for hypokalemia in 4 of 6 patients. The infusion of Mg was extended in 1 patient who had a sustained high TTKG for 24 h; the TTKG remained elevated for 96 h despite normal plasma Mg levels. Conclusions: Bicarbonaturia does not play a critical role in maintaining the very high TTKG in these patients. The K wasting in 4 of 6 of these patients could largely be attributed to hypomagnesemia and/or Mg depletion. The plasma aldosterone level tended to be higher in patients who did not respond to the infusion of Mg. Therefore, these patients may not represent a homogeneous group with regard to the pathophysiology of their renal K wasting.