The Impact of Water and Other Fluids on Pediatric Nephrolithiasis.

Pediatric nephrolithiasis cases have been on the rise in the past several years, resulting in increased healthcare costs and other burdens on the juveniles with this ailment. Recent research has shown that present trends in pediatric nephrolithiasis have changed as a result of fluid intake, including water consumption, nutrition, obesity prevalence, lifestyle, and imaging procedures. A specific cause, meanwhile, is still elusive. Trends in pediatric nephrolithiasis need to be thoroughly researched. Furthermore, variables specific to pediatric nephrolithiasis that could cause greater difficulties in an affected child elevate the level of worry with cumulative prevalence. Doctors should rigorously assess patients who present with kidney stones when they have dynamics such as varied clinical presentation, high recurrence of kidney stones linked to metabolic and urinary tract problems, and the potential existence of rare genetic kidney stone illnesses. This review aims to identify adaptive risk factors and anomalies that call for specialized treatment and prescription. More specifically, the major goals of medical and surgical treatments are to eliminate kidney stone risk and stop relapse while concurrently lowering interventional barriers. A dedicated nephrolithiasis clinic run by a pediatric nephrologist, nutritionist, urologist, and clinical nurse may sometimes be beneficial for patients in serious danger. Such a clinic offers significant chances to learn more about pediatric nephrolithiasis, which has been linked to water consumption and hence fosters urgently required study in this area.

Are individual analyses of multiple short urine collections throughout the 24 hours superior to a standard 24-hour urine collection in precipitation risk assessment of healthy subjects?

PURPOSE: The commonly used 24-hour collection technique has been the mainstay of diagnosis for supersaturation but has some certain limitations. Hence, superiority of multiple short urine collections as a new alternative in precipitation risk assessment was assessed compared to the standard 24-hour urine collection among healthy subjects. MATERIALS AND METHODS: Individual urine samples of 26 healthy subjects were acquired every 2 to 3 hours throughout the 24 hours. Urine samples were obtained and the time and volume of each sample were recorded. Urinary constituents involved in precipitation including, sodium-potassium, chloride, calcium, phosphate, citrate, magnesium, urea, creatinine and pH were measured. A simulated 24-hour collection was recalculated by the totalling of all shorter urine collections volume and urinary constituents excretions throughout the day. RESULTS: Urine pH, urine creatinine and precipitation rate had a significantly lower values in 24-hours urine collection compared to one individual value of multiple urine collections by -0.769 (P < .0001), -7.305 (P < .0001), and - 12.838 (P < .0001), respectively. However, calcium (2.697, P < .0001), citrate (3.54, P < .0001), total phosphate (19.961, P < .0001) and total creatinine (9.579, P < .0001) had statistically significantly higher values in the 24-hours urine collection compared to individual value of multiple urine collections. CONCLUSION: Based on the results, individual analysis of multiple shorter urine collections throughout the day improves the ability of identifying supersaturation points, precipitation risk zones and may potentially improve risk assessment compared to the 24-hour urine collection method.

Alkalinizing Agents: A Review of Prescription, Over-the-Counter, and Medical Food Supplements.

Introduction: Kidney stones affect 1 in every 11 people in the United States each year. There is a significant high recurrence rate without a stone prevention protocol. Alkali citrate is beneficial in decreasing stone recurrence, but because of the cost and gastrointestinal side effects there is a low adherence rate. This study aims to serve as a review of some of the most commonly used alkalizing over-the-counter supplements that are advertised to prevent and treat kidney stones. Methods: Data were gathered by a comprehensive online literature search and company inquiries for kidney stone prevention supplements. An additional informal poll of the authors selected supplements that are most commonly taken by their patients. A total of eight supplements were evaluated for cost, alkali equivalent provided, dosing, and regulatory information. Results: Eight of the most commonly used supplements were reviewed with a focus on alkalizing agents. Information reviewed revealed dosing recommendations resulting in decreased citrate alkali equivalents per day compared with prescription-strength potassium citrate. Cost, peer-reviewed study results, and regulatory data were reviewed, tabulated, and analyzed. Cost per alkali equivalent was substantially decreased for each supplement compared with the prescribed drug. All supplements were found to be readily available online. Conclusion: Over-the-counter alkalizing agents are available to patients and may be an appropriate alternative to cost-prohibitive potassium citrate when treating urolithiasis patients. Additional testing will be necessary in the future to determine the efficacy of these supplements in the treatment and prevention of urinary stone disease.

Assessing Cost-Effectiveness of New Technologies in Stone Management.

Diagnosis, treatment, and follow-up are all influential in determining the overall cost to the health care system for kidney stones. New innovations in the field of nephrolithiasis have been abundant, including disposable ureteroscopes, ultrasound-guided approaches to percutaneous nephrolithotomy, and advanced laser lithotripters. Identifying cost-effective treatment strategies encourages practitioners to be thoughtful about providing value-based high-quality care and remains on important principle in the treatment of urinary stone disease.

Ecological Momentary Assessment of Factors Associated with Water Intake among Adolescents with Kidney Stone Disease.

PURPOSE: Maintaining high water intake decreases kidney stone recurrence but is difficult to do. Strategies to reduce stone recurrence among adolescents are lacking. We conducted an ecological momentary assessment study to identify factors associated with water intake in adolescents with nephrolithiasis. MATERIALS AND METHODS: The study population consisted of 15 female and 10 male patients 12 to 18 years old with at least 1 prior kidney stone. For 7 days participants used "smart" bottles to self-monitor water intake and received questionnaires randomly 4 times daily, which were completed in real time on mobile devices. The questionnaires ascertained awareness of water intake volume, awareness of water intake goals, perceived need to drink, access to water, alternative beverage consumption and attitudes toward bathrooms. Linear mixed effects models were fit to estimate the association between momentary responses and daily water intake. RESULTS: During 175 person-days 595 assessments (85%) were completed. Median daily water intake was 1,304 ml (IQR 848-1,832) and 20% of participants met their intake goal for 4 days or more. Unawareness of water intake volume was associated with drinking 690 ml less water per day (p = 0.04). A strong self-perceived need to drink more was associated with drinking 1,954 ml less water each day compared to no self-perceived need to drink more (p <0.01). Unawareness of intake goals was weakly associated with drinking 1,129 ml less water each day (p = 0.1). Access to water, alternative beverage consumption and bathroom aversion were not associated with water intake. CONCLUSIONS: Unawareness of water volume consumed and low responsiveness to perceived need to drink more were associated with low water intake. Interventions that help adolescents recognize when and identify how to increase water intake may be effective in decreasing stone recurrence.

Dietary and Lifestyle Risk Factors Associated with Incident Kidney Stones in Men and Women.

PURPOSE: Several dietary and lifestyle factors are associated with a higher risk of kidney stones. We estimated the population attributable fraction and the number needed to prevent for modifiable risk factors, including body mass index, fluid intake, DASH (Dietary Approaches to Stop Hypertension) style diet, dietary calcium intake and sugar sweetened beverage intake. MATERIALS AND METHODS: We used data on the HPFS (Health Professionals Follow-Up Study) cohort and the NHS (Nurses' Health Study) I and II cohorts. Information was obtained from validated questionnaires. Poisson regression models adjusted for potential confounders were used to estimate the association of each risk factor with the development of incident kidney stones and calculate the population attributable fraction and the number needed to prevent. RESULTS: The study included 192,126 participants who contributed a total of 3,259,313 person-years of followup, during which an incident kidney stone developed in 6,449 participants. All modifiable risk factors were independently associated with incident stones in each cohort. The population attributable fraction ranged from 4.4% for a higher intake of sugar sweetened beverages to 26.0% for a lower fluid intake. The population attributable fraction for all 5 risk factors combined was 57.0% in HPFS, 55.2% in NHS I and 55.1% in NHS II. The number needed to prevent during 10 years ranged from 67 for lower fluid intake to 556 for lower dietary calcium intake. CONCLUSIONS: Five modifiable risk factors accounted for more than 50% of incident kidney stones in 3 large prospective cohorts. Assuming a causal relation, our estimates suggest that preventive measures aimed at reducing those factors could substantially decrease the burden of kidney stones in the general population.

Current practice patterns of urologists providing nutrition recommendations to patients with kidney stones.

OBJECTIVE: To assess urologists' practice patterns and beliefs about dietary therapy for stone prevention. Dietary therapy is offered to stone formers (SFs) by a subset of urologists. While some may involve a registered dietitian (RD) to provide medical nutrition therapy (MNT), most do not as MNT is Medicare-covered only for diabetes and chronic kidney disease. MATERIALS AND METHODS: An investigator-created survey was distributed to assess Endourological Society members' opinions, confidence, and practices regarding nutrition therapy. RESULTS: Respondents (n=217) practice largely in academic, hospital/clinic, and private settings. Most (82%) felt dietary therapy should be provided regardless of the number of stone events. Most (90%) said the urologist should provide dietary recommendations and more than half (52%) do so for ≥75% of patients (10% provide it for <25%). Time spent with SFs for nutrition varied from ≤4 to ≥10 minutes (31% and 23%) with 64% feeling this to be insufficient time. Of urologists providing counseling, 58% assess their patients' diets. Self-confidence in determining dietary contributors to risk factors and in quantifying intake of foods/nutrients varied (range 45%-82%). Most (76%) said they would like another provider to give recommendations; 23% partner with an RD to do so. CONCLUSIONS: Urologists are interested in dietary stone prevention, despite the fact that the majority have inadequate time to provide it. We identified areas of educational need, specifically, quantifying patients' intake of certain foods/nutrients and identifying whether stone risk factors are diet related. Urologists' skill gaps are precisely the strengths of RDs, and thus, a partnership between RDs and urologists could be beneficial.

How much is a kidney worth? Cost-effectiveness of routine imaging after ureteroscopy to prevent silent obstruction.

PURPOSE: The 2012 American Urological Association (AUA) Clinical Effectiveness Protocols for Imaging in the Management of Ureteral Calculous Disease recommends routine postoperative imaging after ureteroscopy. We evaluated the cost-effectiveness of routine postoperative imaging after ureteroscopy. MATERIALS AND METHODS: We searched the literature to determine the risk of complications after routine ureteroscopy for stones, including the incidence of postoperative pain, stricture and silent obstruction. Sequelae of renal loss due to undiagnosed silent obstruction may include chronic kidney disease, end stage renal disease and cardiovascular disease. Imaging and procedure costs were obtained from Medicare reimbursement rates and the literature. The costs and prevalence of lifetime complications associated with silent loss of 1 kidney were obtained from the renal donor transplant literature. A decision tree was constructed to calculate the cost of a strategy of routinely imaging all patients after ureteroscopy vs selective imaging based on postoperative pain. We performed 1-way and 2-way sensitivity analyses. RESULTS: The average cost per patient of a strategy of routine imaging after ureteroscopy in all patients was $5,326 vs $5,196 for a strategy of selective imaging based on postoperative pain. Assuming a 2% rate of silent obstruction, the cost per kidney saved would be $6,262. CONCLUSIONS: While routine postoperative imaging carries a $130 per patient incrementally higher cost over that of a strategy of selective imaging in patients with postoperative pain, preventing renal loss and its attendant morbidity justifies the additional modest cost.

Research priorities for urological care following spinal cord injury: recommendations of an expert panel.

OBJECTIVE: A multidisciplinary panel of experts from Canada and the United States was convened by the Ontario Neurotrauma Foundation (ONF) to establish research priorities in the area of urological care following spinal cord injury (SCI). DESIGN: The panel reviewed a synthesis of published literature in five areas of urology, identified emerging opportunities in the private and public sector, and used a modified Delphi approach to reach consensus on priorities for funding. RESULTS: The panel recommendations included: clinical trials of the safety and efficacy of M3 receptor specific anti-muscarinic agents for bladder hyperactivity in SCI patients; development and testing of protocols for sacral nerve electrostimulation without sacral afferent neurectomy for management of micturition - including selective stimulation of sacral nerve fibers, high frequency blocking of the pudendal nerve to minimize the risk of urethral sphincter co-contraction and genital nerve stimulation for bladder inhibition and incontinence management; clinical trials of the efficacy and safety of intra-urethral valve catheters; trials of the efficacy of probiotics for bacterial interference i.e. to reduce colonization by uropathogens and manage the dual problems of infection and pathogen resistance to anti-microbials: innovations in the prevention or treatment of stone disease (ureteral, bladder and kidney). CONCLUSIONS: The recommendations form the strategic priorities of the ONF SCI grants program for Ontario-based investigators and their partnerships with out-of-province collaborators and organizations.

[Economic aspects of evidence-based metaphylaxis]. / Okonomische Aspekte der evidenzbasierten Harnsteinmetaphylaxe.

The calculation model which we developed for the cost of stone therapy and metaphylaxis in Germany some years ago with a social health insurance company is based on estimates of stone incidence, types and recurrence rates, actual costs for stone removal, and metaphylaxis (based on data from a district of the social health care system). There are 200,000 stone recurrences per year in Germany. Costs for treatment of these stones amount to $687,000,000. Stone metaphylaxis reduces the recurrence rate by some 40%. The annual cost for stone removal could be lowered by $275,300,000. Metabolic evaluation/metaphylaxis amount to $70,100,000 per year, resulting in a net saving of $205,200,000. In 1997, there were 96 days off work per stone patient resulting in 5,800,000 days off work in Germany per year. Metaphylaxis is not only medically effective in stone formers but also can lower health care cost significantly. Although health care conditions may vary from country to country, in principle this calculation model is applicable also to other countries.

Is prevention of stone recurrence financially worthwhile?

This review shows that the cost of relying solely on minimally-invasive urological procedures for removing stones when patients return with recurrent stones is considerable and is significantly greater that that incurred by screening already proven recurrent stone-formers to identify the risk factors that are causing their stones and then instituting prophylactic measures to prevent stone recurrence. In the UK, at 1998 prices (when the original survey was carried out) for every stone episode prevented, there is a potential saving of almost 2,000 pound to the local Health Authority concerned. In spite of this, many Health Authorities have taken the liberty to discontinue comprehensive stone screening within the past 20 years under the mistaken supposition that minimally-invasive techniques for removing stones have "solved the stone problem". At UCLH in London where such a comprehensive scheme has been in place for the past 8 years, savings of up to 250,000 pound per year can be made by identifying the particular lifestyle as well as the epidemiological, metabolic and nutritional risk factors involved in a given patient and then instituting appropriate measures to prevent further stones.

Drug-induced renal calculi: epidemiology, prevention and management.

Drug-induced calculi represent 1-2% of all renal calculi. The drugs reported to produce calculi formation may be divided into two groups. The first one includes poorly soluble drugs with high urine excretion that favours crystallisation in the urine. Among poorly soluble molecules, triamterene was the leading cause of drug-containing urinary calculi in the 1970s, and it is still currently responsible for a significant number of calculi. In the last decade, drugs used for the treatment of HIV-infected patients, namely indinavir and sulfadiazine, have become the most frequent cause of drug-containing urinary calculi. Besides these drugs, about twenty other molecules may induce nephrolithiasis in patients receiving long-term treatment or high doses. Calculi analysis by physical methods, including infrared spectroscopy or x-ray diffraction, is needed to demonstrate the presence of the drug or its metabolites within the calculi. The second group includes drugs that provoke urinary calculi as a consequence of their metabolic effects. Here, diagnosis relies on careful clinical inquiry because physical methods are ineffective to differentiate between urinary calculi induced by the metabolic effects of a drug and common metabolic calculi. The incidence of such calculi, especially those resulting from calcium/vitamin D supplementation, is probably underestimated. Although drug-induced urinary calculi most often complicate high-dose, long-duration drug treatments, there also exist specific patient risk factors in relation to urine pH, urine output and other parameters, which provide a basis for preventive or curative treatment of calculi. Better awareness of the possible occurrence of lithogenic complications, preventive measures based on drug solubility characteristics and close surveillance of patients on long-term treatment with drugs with lithogenic potential, especially those with a history of urolithiasis, should reduce the incidence of drug-induced nephrolithiasis.

Avaliaçäo de pacientes com litíase renal em regiäo de clima quente / Assessment of kidney stone patients in hot regions

O objetivo deste estudo é desenvolver um serviço de litíase renal e detectar as alteraçöes metabólicas associadas a essa doença em pacientes da cidade de Catanduva, Säo Paulo. Foram estudados 65 pacientes (40 mulheres e 25 homens), entre 1996 e 1999, com idade variando entre 18 e 67 anos. O protocolo utilizado consistiu de avaliaçäo clínica e exames complementares (bioquímica de imagem e dos principais elementos litogênicos plasmáticos e urinários). Para a análise dos resultados, foi utilizado o teste "t" de Student para amostras independentes e consideradas insignificantes quando p é menor que 0,05. Pelo menos, uma alteraçäo metabólica foi encontrada em 98,5 porcento dos casos avaliados.A reduçäo do volume urinário (77 porcento) foi a alteraçäo metabólica mais frequente, seguida pela hipocitratúria (62 porcento), hiperexcreçäo de ácido úrico (32 porcento), hipercalciúria (27 porcento), outras alteraçöes (8 porcento),e sem alteraçäo detectada (1,5 porcento). A detecçäo de, pelo menos, uma alteraçäo metabólica encontrada na grande maioria dos pacientes avaliados comprova a eficácia do protocolo aplicado nesse trabalho. O estudo sugere que a elevada prevalência de alteraçöes metabólicas associadas à litíase renal justifica a investigaçäo sistemática dos pacientes litiásicos. O estabelecimento de centros regionais com serviço de litíase renal deverá näo só favorecer aos pacientes dessas regiöes, bem como contribuir, no sentido epidemiológico, para um maior conhecimento dessa doença no Brasil.(au)

The cost of preventable conditions in adults with spina bifida.

Adults with spina bifida are at risk of developing secondary health conditions that are causally related to the primary condition and are to some degree preventable. By investigating preventable secondary conditions in adults with spina bifida, we can determine the burden of care that might be reduced if preventive strategies were developed. We audited hospitalizations of adults with spina bifida to gain insight into serious secondary conditions in this population. We reviewed all admissions of adults with spina bifida to a large American tertiary care center (Johns Hopkins Hospital; Baltimore, Maryland) over 11 years. We determined the discharge diagnoses for each admission and the hospital costs associated with admission. We defined preventable secondary conditions in this adult population and calculated the percentage of total admissions and of total costs for these secondary conditions. The patient population consisted of spina bifida patients 18 years and over admitted from January 1982 to December 1992, including 59 females and 39 males. 77 of our patients were identified as white, 20 as black, and 1 as "other". Patient age ranged from 18 to 61 years with an average age of 25.8 years. There were 353 admissions and admissions per patient ranged from 1 to 25 over the 11-year period. The average number of admissions per patient was 3.6 and the average length of stay for all admissions was 11.2 days. Of the 353 total admissions, 166 (47.0%) were due to potentially preventable secondary conditions such as serious urologic infections, renal calculi, pressure ulcers, and osteomyelitis. For admissions due to these secondary conditions, the average length of stay was 12.5 days. The total hospital costs, excluding professional fees, were $175,885, $247,355, and $437,262 for 1990, 1991, and 1992 respectively. Permanent loss of function resulting from secondary conditions, not investigated in this study, can also be a source of long-term financial and psychological cost to the patient. This study found a high number of patients with multiple admissions and that many admissions qualified as potentially preventable. More information is needed if we are to understand the factors associated with secondary health conditions in adults with spina bifida. We need to investigate the roles played by physician and patient knowledge, attitudes, and behaviors in contributing to patient outcome.

The financial effects of kidney stone prevention.

Prevention of nephrolithiasis (NL) is now medically feasible and widely recommended. However, diagnosis and treatment of remediable causes of stones requires testing and drugs that impose a cost; this cost is balanced by the presumed reductions in stone related events and medical encounters. In order to assess the balance between these, we have analyzed results from 1092 patients with NL unselected except for having clinical follow-up during treatment. From this population, we have derived the changes in rates of new stones, hospitalizations, cystoscopies, and surgical procedures. From these changes, and assignment of a range of possible dollar costs, we estimate that medical stone prevention will result in an average saving of $2,158 +/- $500 (SEM)/patient/year, which is the difference between an expenditure of $1,068/patient on yearly drugs and testing, and a reduction of $3,226 per patient in medical costs. Medical prevention of NL seems justified on a cost saving basis quite apart from its benefits to patients in terms of reduced morbidity and risk from procedures, obstruction, and infection.

Tratamiento de la nefrolitiasis y la ureterolitiasis / Nephrolithiasis and ureteroliasis treatment

El desarrollo tecnológico esta revolucionando el tratamiento de la litiasis urinaria mediante la introducción de métodos no quirúrgicos e incluso no invasores que garantizan elevadas tasas de curación con minimas complicaciones y enorme reducción de la incapacidad posterior al tratamiento. Una vez eliminados los cálculos, el tratamiento médico puede ayudar a prevenir las recidivas con base en un adecuado estudio de los factores de riesgo y su modificación mediante diversas modalidades terapéuticas que permitan corregir las alteraciones fisicoquímicas responsables de la formación de cálculos urinarios.

Outpatient metabolic evaluation of patients with recurrent kidney stones.

We have designed an outpatient, comprehensive metabolic evaluation program for patients with recurrent kidney stone disease. This protocol can be expected to detect and identify specific biochemical abnormalities contributing to kidney stone formation in about 95% of these patients. Individualized therapy can then be started based on the particular metabolic defect discovered in each patient. This diagnostic and treatment program will stop new kidney stone formation in these high-risk patients virtually completely. For each stone-related hospitalization eliminated, the average savings are at least $2,700. The total potential savings in our small community alone are over $460,000! Our metabolic stone evaluation protocol is the only one with which we are familiar that was designed and implemented exclusively at the community hospital level. It is readily adaptable to other medical facilities.