Hydration Status and Kidney Health of Factory Workers Exposed to Heat Stress: A Pilot Feasibility Study.

Dehydration associated with heat stress increases the risk of workplace injury or illness, decreases productivity, and may contribute to the chronic kidney disease epidemic identified in outdoor workers from hot climates. There is limited research on the effects of chronic occupational heat stress among indoor workers. We aimed to test the feasibility of measuring markers of hydration and kidney function in foundry factory workers in Southern Brazil, exposed and not exposed to heat stress. Factory workers exposed to heat stress (wet bulb globe temperature ≥28.9) and not exposed to heat were identified by management and invited to participate. Clinical and biochemical markers of hydration and kidney function were evaluated before and after a single 8.5 h work shift (lunch time not included). Feasibility outcomes included rates of enrolment, % completion of study protocols, and time to complete data collection. This study was deemed feasible with 80% enrolment and 90% completion of the protocol. Among the preselected workers, the enrolment rate was 91%. All subjects completed the physiological measures and blood collection and 95% completed the urine studies. Mean time to complete data collection pre-shift was 19.1 ± 4.2 min and post-shift: 14.3 ± 4.0 min. Workers exposed to heat stress had a greater decline in estimated glomerular filtration rate compared to controls over the work shift (-13 ± 11 vs. -5 ± 7 mL/min; p < 0.01). We demonstrated the feasibility and challenges of conducting future hydration and kidney function research among indoor factory workers. Further study is needed to determine if exposure to indoor heat contributes to a decline in kidney function.

Saliva Urea Nitrogen Continuously Reflects Blood Urea Nitrogen after Acute Kidney Injury Diagnosis and Management: Longitudinal Observational Data from a Collaborative, International, Prospective, Multicenter Study.

BACKGROUND: Acute kidney injury (AKI) is a growing global concern and often reversible. Saliva urea nitrogen (SUN) measured by a dipstick may allow rapid diagnosis. We studied longitudinal agreement between SUN and blood urea nitrogen (BUN) and the diagnostic performance of both. METHODS: Agreement between SUN and BUN and diagnostic performance to diagnose AKI severity in AKI patients in the United States and Brazil were studied. Bland-Altman analysis and linear mixed effects models were employed to test the agreement between SUN and BUN. Receiver operating characteristics statistics were used to test the diagnostic performance to diagnose AKI severity. RESULTS: We found an underestimation of BUN by SUN, decreasing with increasing BUN levels in 37 studied patients, consistent on all observation days. The diagnostic performance of SUN (AUC 0.81, 95% CI 0.63-0.98) was comparable to BUN (AUC 0.85, 95% CI 0.71-0.98). CONCLUSION: SUN reflects BUN especially in severe AKI. It also allows monitoring treatment responses. Video Journal Club 'Cappuccino with Claudio Ronco' at http://www.karger.com/?doi=445041.

Saliva urea nitrogen dipstick - a novel bedside diagnostic tool for acute kidney injury.

BACKGROUND AND AIMS: Measurement of saliva urea nitrogen (SUN) may be valuable in the screening of kidney failure. Here we evaluate the diagnostic performance of SUN dipsticks in patients with acute kidney injury (AKI). MATERIAL AND METHODS: We measured SUN and blood urea nitrogen (BUN) in hospitalized patients diagnosed with AKI based on Acute Kidney Injury Network (AKIN)-criteria. After collection, saliva was transferred to a colorimetric SUN dipstick. We then compared the resultant test-pad color to six standardized color fields indicating SUN of 5 - 14 (#1), 15 - 24 (#2), 25 - 34 (#3), 35 - 54 (#4), 55 - 74 (#5), and ≥ 75 (#6) mg/dL, respectively. We assessed the performance of SUN and BUN to discriminate AKIN 3 from earlier stages by the area under receiver operating characteristic curves (AUC ROC). RESULTS: We enrolled 44 patients (59.5 ± 18 years, 58% female; pre-renal AKI: 67%; renal 24%; post-renal 9%) in AKIN stages 1 (59%), 2 (16%), and 3 (25%). SUN and BUN levels were correlated (Spearman rank Rs = 0.69; p < 0.001, n = 44) with the highest correlation in AKIN 1 (Rs = 0.63, p = 0.001, n = 26). SUN allowed a significant discrimination of AKIN 3 from earlier stages (AUC ROC 0.91; 95% CI 0.80 - 1.0), which was comparable to the diagnostic performance of BUN (AUC ROC 0.90; 95% CI 0.78 - 1.0). CONCLUSIONS: SUN dipsticks allow the discrimination of AKIN 3 from earlier AKI stages. This low-technology approach may aid the screening of severe AKI in areas where laboratory resources are scarce.

Similar outcomes of catheters implanted by nephrologists and surgeons: analysis of the Brazilian peritoneal dialysis multicentric study.

A good catheter implantation technique is important to allow for effective peritoneal access function and long-term technique survival. Studies regarding results obtained by nephrologists in comparison with surgeons have been limited to small single-center experiences. Thus, the objective of this study was to explore the impact of the peritoneal dialysis (PD) catheter insertion operator on early catheter complications and on technique survival in a large national multicentric cohort study (Brazilian Peritoneal Dialysis Multicentric Study, BRAZPD). Adult incident patients recruited in the BRAZPD from December 2004 to October 2007 having undergone first PD catheter implantation were included in the analysis. Mechanical and infectious early complication rates were defined as time to the first event occurring up to 3 months after catheter insertion and adjusted for comorbidities. Valid data of 736 patients (mean age of 59 ± 16 years old, 52% women, 61% white) were analyzed. Mechanical (HR 0.99 [CI 0.56-1.76]; p = 0.98) and infectious (HR 0.63 [CI 0.32-1.23]; p = 0.17) early complication rates were similar between groups. Long-term catheter survival was also similar between groups. Early complications rates and catheter survival were similar between groups defined by operator profile (nephrologist or surgeon), supporting the role of interventional nephrology in the placement of PD catheters.

Kidney Function in Factory Workers Exposed to Heat Stress: A 2-Year Follow-up Study.

OBJECTIVES: The aims of the study are to re-evaluate kidney function in workers exposed and not exposed to heat stress after 2 years and to compare kidney function cross-shift using creatinine and cystatin C. METHODS: Participants were workers from a metallurgical industry. The clinical and biochemical markers of hydration and kidney function were evaluated before and after a single shift in work. RESULTS: We included 14 workers (6 in the heat group and 8 in the control group). The serum creatinine levels did not change during the follow-up period. Cross-shift, creatinine-based eGFR (estimated glomerular filtration rate) decreased, and cystatin C-based eGFR was maintained in the heat and control groups. CONCLUSIONS: Workers exposed to heat stress maintained their kidney function after a 2-year follow-up. Cystatin C is a better kidney function marker than creatinine for cross-shift assessments in this setting.

Female nurses have a higher prevalence of urinary tract symptoms and infection than other occupations in dialysis units.

INTRODUCTION: Urinary tract symptoms and infection have been associated with occupational factors that impact hydration habits particularly in women. We compared self-reported urinary symptoms and infection and hydration habits between nurses and other occupations in dialysis units. METHODS: Cross-sectional study. Participants worked in five nephrology centers in Brazil and answered an online questionnaire comprising questions regarding urinary tract symptoms and infection episodes in the preceding year; data on usual daily beverage intake, urine frequency, and urine color according to a urine color chart were also collected, as well as perceptions of water access and toilet adequacy at work. RESULTS: We included 133 women (age=36.9±9.5 years). The self-reported usual daily beverage intake was 6.6±2.9 cups/day (~1320 mL), daily urine frequency was 5.4±2.1, and urine color chart score: 3.0±1.2. Nurses (N=66/49.6%) reported higher prevalence of burning sensation (50 versus 27%; P<0.001), urinary urgency (42 versus 21%; P<0.001), and infection (42% versus 25%; P=0.04) as well as lower liquid intake (6.0±2.6 versus 7.3±3.0 cups/day; P=0.01) than controls. Forty four percent of nurses reported being able to drink when thirsty "always" and "most of the time" versus 93% of the control group. CONCLUSION: Dialysis female nurses reported lower beverage intake and higher prevalence of symptoms and infection than other occupations in the same environment. Interventions to improve hydration can potentially decrease urinary problems in this population.

Development and implementation of telehealth for peritoneal dialysis and kidney transplant patients monitoring during the COVID-19 pandemic.

The coronavirus (Sars-Cov-2) pandemic raised the need for social distance to reduce its spread. Chronic kidney disease patients on renal replacement therapy are especially susceptible to developing the most severe form of COVID-19, and, at the same time, require regular medical and multidisciplinary periodic follow-up. On an emergency basis, Brazil's professional regulatory bodies authorized telehealth assistance, which made possible to migrate from face-to-face to distance appointments in health services across the country, when necessary. This article's main objective is to describe the process of developing and implementing telehealth for monitoring renal transplant patients and patients on peritoneal dialysis during the COVID-19 pandemic.

Perceptions of hemodialysis patients about dietary and fluid restrictions.

INTRODUCTION: Dietary regimen for hemodialysis (HD) patients is complicate and identifying characteristics and reasons of those most likely to experience difficulty in adhering to dietary restrictions is important. OBJECTIVE: To quantify HD patient's perceptions about dietary and fluid restrictions, acknowledge individual reasons that facilitate or complicate their adherence, and also their relationship with demographic, nutritional and clinical characteristics. METHODS: Multi-center cross-sectional study in five dialysis facilities. HD patients (n = 147; 48% male; age: 51,3 ± 13,6 years) were encouraged to score on a scale of 0 to 10 their perception of the degree of difficulty to adhere the nutritional advice regarding control of sodium, fluid, potassium and phosphorus intake. RESULTS: Sodium score was 4(1-7), fluids 6(3-8), potassium 4(2-6) and phosphate 6(3-8). Percentage of patients who perceived a greater difficulty (score ≥ 6) to control fluids and phosphate intake was higher than for sodium and potassium. Participants with excessive % interdialytic weight gain (%IDWG) had a higher score for fluids; the ones with hypercalemia perceived more difficulty to control potassium intake than others as well as hyperphosphatemic patients compared to normophosphatemic to control phosphorus intake. Participants with a greater difficulty to control sodium intake also perceived a greater difficulty to control fluids, potassium and phosphate intake. CONCLUSION: Participants perceived a greater difficulty to control fluid and phosphate intake rather than sodium and potassium, higher perceptions scores were associated with subgroups and with worse control of clinical parameters. Moreover, patients with a greater difficulty to control some dietary item also found harder to control the other ones.

Female nurses have a higher prevalence of urinary tract symptoms and infection than other occupations in dialysis units / Técnicas de enfermagem têm uma prevalência maior de sintomas e infecções do trato urinário do que outras ocupações em unidades de diálise

Abstract Introduction: Urinary tract symptoms and infection have been associated with occupational factors that impact hydration habits particularly in women. We compared self-reported urinary symptoms and infection and hydration habits between nurses and other occupations in dialysis units. Methods: Cross-sectional study. Participants worked in five nephrology centers in Brazil and answered an online questionnaire comprising questions regarding urinary tract symptoms and infection episodes in the preceding year; data on usual daily beverage intake, urine frequency, and urine color according to a urine color chart were also collected, as well as perceptions of water access and toilet adequacy at work. Results: We included 133 women (age=36.9±9.5 years). The self-reported usual daily beverage intake was 6.6±2.9 cups/day (~1320 mL), daily urine frequency was 5.4±2.1, and urine color chart score: 3.0±1.2. Nurses (N=66/49.6%) reported higher prevalence of burning sensation (50 versus 27%; P<0.001), urinary urgency (42 versus 21%; P<0.001), and infection (42% versus 25%; P=0.04) as well as lower liquid intake (6.0±2.6 versus 7.3±3.0 cups/day; P=0.01) than controls. Forty four percent of nurses reported being able to drink when thirsty "always" and "most of the time" versus 93% of the control group. Conclusion: Dialysis female nurses reported lower beverage intake and higher prevalence of symptoms and infection than other occupations in the same environment. Interventions to improve hydration can potentially decrease urinary problems in this population.

Resumo Introdução: Sintomas e infecções do trato urinário têm sido associados a fatores ocupacionais que afetam hábitos de hidratação, particularmente em mulheres. Comparamos sintomas e infecções urinárias autorrelatados e hábitos de hidratação entre técnicas de enfermagem e outras ocupações em unidades de diálise. Métodos: Estudo transversal. As participantes trabalhavam em cinco centros de nefrologia no Brasil e responderam um questionário online contendo perguntas sobre sintomas do trato urinário e episódios de infecção no ano anterior; também foram coletados dados sobre a ingestão diária habitual de bebidas, frequência e cor da urina de acordo com uma tabela de cores da urina, assim como percepções sobre o acesso à água e adequação das instalações sanitárias no trabalho. Resultados: Incluímos 133 mulheres (idade=36,9±9,5 anos). Em média, as participantes relataram ingestão de bebidas de 6,6±2,9 copos/dia (~1320 mL), frequência urinária de 5,4±2,1 vezes/dia e escore da tabela de cores da urina de 3,0±1,2. Técnicas de enfremagem (N=66/49,6%) relataram maior prevalência de sensação de ardor (50 versus 27%; P<0,001), urgência urinária (42 versus 21%; P<0,001), e infecção (42% versus 25%; P=0,04), bem como menor ingestão de líquidos (6,0±2,6 versus 7,3±3,0 copos/dia; P=0,01) do que controles. Quarenta e quatro por cento das técnicas de enfermagem relataram poder beber quando têm sede "sempre" e "na maioria das vezes" contra 93% do grupo controle. Conclusão: Técnicas de enfermagem de unidades de diálise relataram menor ingestão de bebidas e maior prevalência de sintomas e infecção do que outras ocupações no mesmo ambiente de trabalho. Intervenções para melhorar a hidratação podem diminuir problemas urinários nesta população.

Development and implementation of telehealth for peritoneal dialysis and kidney transplant patients monitoring during the COVID-19 pandemic / Desenvolvimento e implementação do atendimento a distância para acompanhamento de pacientes em diálise peritoneal e tranplantados renais durante a pandemia de covid-19

Abstract The coronavirus (Sars-Cov-2) pandemic raised the need for social distance to reduce its spread. Chronic kidney disease patients on renal replacement therapy are especially susceptible to developing the most severe form of COVID-19, and, at the same time, require regular medical and multidisciplinary periodic follow-up. On an emergency basis, Brazil's professional regulatory bodies authorized telehealth assistance, which made possible to migrate from face-to-face to distance appointments in health services across the country, when necessary. This article's main objective is to describe the process of developing and implementing telehealth for monitoring renal transplant patients and patients on peritoneal dialysis during the COVID-19 pandemic.

Resumo A pandemia do coronavírus (Sars-CoV-2) trouxe a necessidade do isolamento social para a diminuição de sua propagação. Pacientes renais crônicos em terapia renal substitutiva são especialmente suscetíveis a desenvolverem a forma mais grave da covid-19, e, ao mesmo tempo, necessitam de acompanhamento médico e multidisciplinar regular com consultas periódicas. Em caráter emergencial, órgãos regulatórios profissionais brasileiros passaram a autorizar o atendimento da equipe de saúde por meio da teleconsulta, o que tornou possível a migração das consultas presenciais para consultas a distância nos serviços de saúde em todo o país, quando necessário. O principal objetivo deste artigo foi descrever o processo de desenvolvimento e implementação da teleorientação para acompanhamento de pacientes transplantados renais e em diálise peritoneal de um serviço de Joinville, SC, durante a pandemia de covid-19.

[Quantification of the stone clinic effect in patients with nephrolithiasis]. / Quantificação do stone clinic effect em pacientes com nefrolitíase.

BACKGROUND: The "stone clinic effect" refers to the effect of encouraging a high intake of fluid and diet counseling in the clinical evolution of kidney stone disease. OBJECTIVE: Our objective was to determine the extent of this variable in patients with nephrolithiasis. METHODS: Twenty-five patients (11 female and 14 male, 47.64+/-10.55 years old) with recurrent nephrolithiasis were prospectively followed for one year, with 3-month interval medical evaluation. Patients were advised to increase the fluid intake, and to limit the intake of salt and protein. No patient was submitted to pharmacological therapy. Two 24-hour urine samples were collected at baseline (S1) and in the end of follow-up (S2) for the measurement of creatinine, calcium, sodium, uric acid, citrate, oxalate and magnesium. Metabolic and radiological activity was also assessed. Urinary calcium oxalate supersaturation (SS) was calculated by Tiselius index. RESULTS: Eleven (44%) patients had hypocitraturia, 9 (36%) hypercalciuria and 5 (20%) hyperuricosuria. Urinary volume increased (1903+/-811 vs. 2381+/-919 ml/day, p<0.05) and SS decreased significantly (1.13+/-0.8 vs. 0.6+/-0.2, p<0.01). During follow-up, the number of stones decreased when compared to baseline (S1 = 2.04+/-1.51 vs. S2 = 0.72+/- 0.23 stones, p<0.001). There was no evidence of new stone formation or growth in 20 of 25 patients (80%). CONCLUSIONS: The "stone clinic effect" significantly decreased urinary SS for calcium oxalate and the formation of new kidney stones in 80% of patients during first year of follow-up.

Perceptions of hemodialysis patients about dietary and fluid restrictions / Percepções de pacientes em hemodiálise sobre as restrições alimentares

Abstract Introduction: Dietary regimen for hemodialysis (HD) patients is complicate and identifying characteristics and reasons of those most likely to experience difficulty in adhering to dietary restrictions is important. Objective: To quantify HD patient's perceptions about dietary and fluid restrictions, acknowledge individual reasons that facilitate or complicate their adherence, and also their relationship with demographic, nutritional and clinical characteristics. Methods: Multi-center cross-sectional study in five dialysis facilities. HD patients (n = 147; 48% male; age: 51,3 ± 13,6 years) were encouraged to score on a scale of 0 to 10 their perception of the degree of difficulty to adhere the nutritional advice regarding control of sodium, fluid, potassium and phosphorus intake. Results: Sodium score was 4(1-7), fluids 6(3-8), potassium 4(2-6) and phosphate 6(3-8). Percentage of patients who perceived a greater difficulty (score ≥ 6) to control fluids and phosphate intake was higher than for sodium and potassium. Participants with excessive % interdialytic weight gain (%IDWG) had a higher score for fluids; the ones with hypercalemia perceived more difficulty to control potassium intake than others as well as hyperphosphatemic patients compared to normophosphatemic to control phosphorus intake. Participants with a greater difficulty to control sodium intake also perceived a greater difficulty to control fluids, potassium and phosphate intake. Conclusion: Participants perceived a greater difficulty to control fluid and phosphate intake rather than sodium and potassium, higher perceptions scores were associated with subgroups and with worse control of clinical parameters. Moreover, patients with a greater difficulty to control some dietary item also found harder to control the other ones.

Resumo Introdução: as recomendações dietéticas para pacientes em hemodiálise (HD) são complexas e identificar as características e as razões das pessoas com maior dificuldade em aderir às restrições de alimentos e bebidas pode ser fundamental. Objetivos: quantificar as percepções dos pacientes em HD sobre as restrições alimentares e de líquidos, reconhecer as razões individuais que facilitam ou complicam sua adesão, bem como sua relação com as características demográficas, nutricionais e clínicas. Métodos: estudo transversal multicêntrico realizado em cinco unidades de diálise. Os pacientes em HD (n = 147, 48% do sexo masculino, idade: 51,3 ± 13,6 anos) foram encorajados a pontuar em uma escala de 0 a 10 a sua percepção do grau de dificuldade de aderir ao aconselhamento nutricional para o controle de sódio, líquidos, potássio e fósforo. Resultados: o escore de sódio foi 4 (1-7); de líquidos 6 (3-8); de potássio 4 (2-6); e de fosfato 6 (3-8). O precentual de pacientes que percebiam uma maior dificuldade (escore ≥ 6) no controle de líquidos e de fosfato foi maior do que para o sódio e o potássio. Os participantes com elevado ganho de peso interdialitico (%GPID) referiram maior pontuação para líquidos; os com hipercalemia perceberam mais dificuldade para controlar a ingestão de potássio que os demais, bem como os pacientes hiperfosfatêmicos em comparação com os normofosfatêmicos para controlar a ingestão de fósforo. Os participantes com maior dificuldade para controlar a ingestão de sódio também perceberam uma maior dificuldade para controlar o consumo dos demais itens investigados. Conclusão: os participantes perceberam maior dificuldade no controle da ingestão de líquidos e de fontes de fosfato do que de sódio e potássio. Maiores escores de percepção foram associados a alguns subgrupos e a pior controle dos parâmetros clínicos. Além disso, os pacientes com maior dificuldade para controlar algum item dietético também referiram ser mais difícil de controlar os outros itens investigados.

Changes in calcium oxalate crystal morphology as a function of supersaturation.

PURPOSE: To study the changes in calcium oxalate crystal morphology induced by different levels of supersaturation (SS) in human urine. MATERIALS AND METHODS: Twenty-four hours urine samples from 5 normal men were collected. Each specimen was centrifuged and filtered. About 200 mL of each sample was dialyzed overnight. Aliquots of 2 mL of urine was then added to a 24-wells tissue culture plate and checked for crystal absence. Calcium oxalate crystals were precipitated from each sample by adding sodium oxalate and calcium chloride in sufficient quantities to induce spontaneous crystallization. Finally, each plate hole was examined with an inverted polarized microscope (X500 magnification). Initial SS of each sample relative to calcium oxalate was calculated using an iterative computer program. RESULTS: Crystal formation was connected to relative calcium oxalate (CaOx) SS. At SS of 10, small crystals of similar shape were formed, mainly CaOx dihydrate morphology. At SS of 30, there was an enormous increase in the number of crystals, that kept the same size. SS greater than 50 produced larger crystals with different shapes and multiple crystalline aggregates. Urine was able to tolerate, i.e., to avoid crystal formation, until SS ratios of approximately 10. CONCLUSIONS: Relative CaOx SS and the concentration ratio of calcium to oxalate are important determinanting factors of crystal morphology. Non-dialyzable urinary proteins can act as inhibitors and influence the structure of formed crystals. Additional studies from patients with kidney stones are needed in order to establish whether crystal size and habit distribution are different from crystals in normal urine.

Changes in calcium oxalate crystal morphology as a function of supersaturation

PURPOSE: To study the changes in calcium oxalate crystal morphology induced by different levels of supersaturation (SS) in human urine. MATERIALS AND METHODS: Twenty-four hours urine samples from 5 normal men were collected. Each specimen was centrifuged and filtered. About 200 mL of each sample was dialyzed overnight. Aliquots of 2 mL of urine was then added to a 24-wells tissue culture plate and checked for crystal absence. Calcium oxalate crystals were precipitated from each sample by adding sodium oxalate and calcium chloride in sufficient quantities to induce spontaneous crystallization. Finally, each plate hole was examined with an inverted polarized microscope (X500 magnification). Initial SS of each sample relative to calcium oxalate was calculated using an iterative computer program. RESULTS: Crystal formation was connecte to relative calcium oxalate (CaOx) SS. At SS of 10, small crystals of similar shape were formed, mainly CaOx dihydrate morphology. At SS of 30, there was an enormous increase in the number of crystals, that kept the same size. SS greater than 50 produced larger crystals with different shapes and multiple crystalline aggregates. Urine was able to tolerate, i.e., to avoid crystal formation, until SS ratios of approximately 10. CONCLUSIONS: Relative CaOx SS and the concentration ratio of calcium to oxalate are important determinanting factors of crystal morphology. Non-dialyzable urinary proteins can act as inhibitors and influence the structure of formed crystals. Additional studies from patients with kidney stones are needed in order to establish whether crystal size and habit distribution are different from crystals in normal urine.

Quantificação do stone clinic effect em pacientes com nefrolitíase / Quantification of the stone clinic effect in patients with nephrolithiasis

O termo stone clinic effect refere-se ao efeito do aumento da ingestão hídrica e aconselhamento dietético na evolução clínica da doença calculosa renal. OBJETIVO: O nosso objetivo foi quantificar esta variável em pacientes portadores de nefrolitíase. MÉTODOS: Vinte e cinco pacientes (11 mulheres e 14 homens; 47,64±10,55 anos) com nefrolitíase recorrente foram acompanhados com consultas trimestrais por um ano. Orientações sobre aumento da ingestão hídrica, diminuição do consumo de sal e proteína foram rotineiramente fornecidas. Nenhum paciente foi submetido à terapia farmacológica. Foram coletados no início (S1) e no final do seguimento (S2) os seguintes parâmetros: atividade clínica e radiológica da doença litiásica, urina de 24 horas com dosagem de creatinina, cálcio, sódio, ácido úrico, citrato, oxalato e magnésio. A supersaturação (SS) para o oxalato de cálcio foi calculada pelo índice de Tiselius. RESULTADOS: Onze (44 por cento) pacientes apresentaram hipocitratúria, nove (36 por cento) hipercalciúria e cinco (20 por cento) hiperuricosúria. Houve aumento do volume urinário (1903±811 vs 2381±919 ml/dia, p<0,05) e diminuição significativa na SS urinária (1,13±0,8 vs 0,6±0,2, p<0,01). O número de cálculos formados foi menor quando comparado com o mesmo período de seguimento pré-estudo (S1=2,04±1,51 vs S2= 0,72±0,23 cálculos, p<0,001). Não houve formação ou crescimento de cálculos preexistentes em 20 dos 25 pacientes (80 por cento). CONCLUSÕES: O stone clinic effect diminuiu significativamente a SS urinária para o oxalato de cálcio e a ocorrência de novos cálculos em 80 por cento dos pacientes durante o primeiro ano de acompanhamento.