In men with recurrent calcium oxalate stones and hypercalciuria, restricted intake of animal protein and salt, combined with a normal calcium intake, provides greater protection than the traditional low-calcium diet.

A significant percentage of hypertensive subjects has a greater risk of renal stone formation, especially when hypertension is associated with excessive body weight. Higher oxaluria and calciuria as well as supersaturation of calcium oxalate and uric acid appear to be the most important factors. Excessive weight and consumption of salt and animal proteins may also play an important role.

The total elimination of fruits and vegetables in normal subjects brings about adverse changes in the urinary stone risk profile that are only partially counterbalanced by a reduction in oxalate. In contrast, the addition of these foods to the diet of hypocitraturic stone formers not used to eating them not only significantly increases citrate excretion without affecting oxalate excretion, but also decreases calcium oxalate and uric acid relative saturation.

Background: A high fluid intake is the oldest existing treatment for kidney stones, and, up until a few decades ago, it was the only preventive measure at the physician’s disposal for stone recurrences. Methods: Using the data available in literature and partly unpublished personal research, we examine the role of urine volume as a stone risk factor, its impact on calcium crystallization mechanisms and its real importance as a means of prevention. Results: To sum up, the most important findings are: (1) a low urine volume must be considered as a real risk factor, both as regards the onset of renal calculi and stone relapses; (2) an increase in urine volume induced by a high water intake produces favourable effects on the crystallization of calcium oxalate and does not reduce the activity of natural inhibitors; (3) a sufficiently high intake of water and probably other fluids such as coffee, tea, beer and wine has a preventive effect on nephrolithiasis and its recurrence, and (4) the role of fruit juice is still to be defined. Conclusions: A high intake of fluids, especially water, is still the most powerful and certainly the most economical means of prevention of nephrolithiasis, and it is often not used to advantage by stone formers.

BackgroundOver 20% of hospital bed use is inappropriate, implying a waste of resources and the increase of patient iatrogenic risk.MethodsThis is a cluster, pragmatic, randomised controlled trial, carried out in a large University Hospital of Northern Italy, aiming to evaluate the effect of a strategy to reduce unnecessary hospital days. The primary outcome was the percentage of patient-days compatible with discharge. Among secondary objectives, to describe the strategy’s effect in the long-term, as well as on hospital readmissions, considered to be a marker of the quality of hospital care. The 12 medical wards with the longest length of stay participated. Effectiveness was measured at the individual level on 3498 eligible patients during monthly index days. Patients admitted or discharged on index days, or with stay >90 days, were excluded. All ward staff was blinded to the index days, while staff in the control arm and data analysts were blinded to the trial’s objectives and interventions. The strategy comprised the distribution to physicians of the list of their patients whose hospital stay was compatible with discharge according to a validated Delay Tool, and of physician length of stay profiles, followed by audits managed autonomously by the physicians of the ward.ResultsDuring the 12 months of data collection, over 50% of patient-days were judged to be compatible with discharge. Delays were mainly due to problems with activities under medical staff control. Multivariate analysis considering clustering showed that the strategy reduced patient-days compatible with discharge by 16% in the intervention vs control group, (OR=0.841; 95% CI, 0.735 to 0.963; P=0.012). Follow-up at 1 year did not yield a statistically significant difference between the percentages of patient-days judged to be compatible with discharge between the two arms (OR=0.818; 95% CI, 0.476 to 1.405; P=0.47). There was no significant difference in 30-day readmission and mortality rates for all eligible patients (N=3498) between the two arms.ConclusionsResults indicate that a strategy, involving physician direct accountability, can reduce unnecessary hospital days. Relatively simple interventions, like the one assessed in this study, should be implemented in all hospitals with excessive lengths of stay, since unnecessary prolongation may be harmful to patients.Trial registrationClinicalTrials.gov, identifier NCT01422811.