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Acute kidney injury (AKI) is defined and staged by reduced urine output (UO) and increased serum creatinine (SCr). UO is typically measured manually and documented in the electronic health record, making early and reliable detection of oliguria-based AKI and electronic data extraction challenging. The authors investigated the diagnostic performance of continuous UO, enabled by active drain line clearance–based alerts (Accuryn AKI Alert), compared with AKI stage 2 SCr criteria and their associations with length of stay, need for continuous renal replacement therapy, and 30-day mortality. This study was a prospective and retrospective observational study. Nine tertiary centers participated. Cardiac surgery patients were enrolled. None. A total of 522 patients were analyzed. AKI stages 1, 2, and 3 were diagnosed in 32.18%, 30.46%, and 3.64% of patients based on UO, compared with 33.72%, 4.60%, and 3.26% of patients using SCr, respectively. Continuous UO-based alerts diagnosed stage ≥1 AKI 33.6 (IQR =15.43, 95.68) hours before stage ≥2 identified by SCr criteria. A SCr-based diagnosis of AKI stage ≥2 has been designated a Hospital Harm by the Centers for Medicare & Medicaid Services. Using this criterion as a benchmark, AKI alerts had a discriminative power of 0.78. The AKI Alert for stage 1 was significantly associated with increased intensive care unit and hospital length of stay and continuous renal replacement therapy, and stage ≥2 alerts were associated with mortality. AKI Alert, based on continuous UO and enabled by active drain line clearance, detected AKI stages 1 and 2 before SCr criteria. Early AKI detection allows for early kidney optimization, potentially improving patient outcomes. [ABSTRACT FROM AUTHOR]

The list of standard abbreviations for JDS is available at adsa.org/jds-abbreviations-24. Nonstandard abbreviations are available in the Notes. Urine output and urinary urea-N excretion (UUN e) excretion are critical measures to accurately evaluate N metabolism in lactating dairy cows and environmental concerns related to manure N. The objectives of this study were: (1) to compare estimates of UUN e , urine output, and related variables from 3 pre-established measurement protocols (bladder catheterization, external collection cup, and spot sampling) and from dietary salt supplementation, (2) to study temporal variation in UUN e , urine output, and related variables as affected by measurement protocol, and (3) to evaluate urine specific gravity as a predictor of urine output. Twelve multiparous Holstein cows were used in a split-plot, Latin square design. Cows were randomly assigned to a diet (main plot) containing either 0.7% or 1.6% NaCl (DM basis) and then assigned to a sequence of 3 protocols (subplot) in a balanced 3 × 3 Latin square with 14-d period. For each protocol, measurements were conducted every 4 h for 3 consecutive days. Urine output was determined gravimetrically for bladder catheterization and external collection cup or based on measured cow BW, measured urinary creatinine concentration, and the assumed creatinine excretion of 29 mg/kg BW per day for spot sampling. Urine specific gravity was measured by refractometry. When averaged over a 3-d measurement period and compared with bladder catheterization, spot sampling underestimated urine output (6.8 kg/d; 20%) and UUN e (26 g/d; 13%) but exhibited greater concentration of urinary urea-N (+58 mg/dL; 10%). There were no differences in any measurements determined via bladder catheterization or external cup device protocols, except for urine output that tended to be 3.7 kg/d lower for collection cup compared with bladder catheterization. The 2 gravimetric protocols yielded lower urinary creatinine concentration than spot sampling (64.7 vs. 88.1 mg/dL) and lower creatinine excretion (25.3 mg/kg BW per day) than the value of 29 mg/kg BW per day generally assumed in the spot sampling protocol. Salt supplementation tended to increase urine output (+5.2 kg/d) and decrease urinary urea-N concentration (−93 mg/dL), urinary creatinine concentration (−9.5 mg/dL), milk protein concentration (−0.19 percentage unit) and milk protein yield (−70 g/d). There was greater temporal variation of urine output when measured via the collection cup compared with bladder catheterization in the first 2 d but not the third day of sampling, suggesting that an extended period of adaptation might have improved data quality of the collection cup protocol. The R2 of the linear regression to predict urine output with urine specific gravity was 67%, 73%, and 32% for bladder catheterization, collection cup, and spot sampling, respectively. In this study, spot sampling underestimated both urine output and UUN e , but UUN e determination did not differ between external collection cup and bladder catheterization. However, our data suggested the need to investigate the adaptation protocol, required days of measurements and the conversion of urine mass to urine volume to improve accuracy and precision of urine collection protocols. [Display omitted] [ABSTRACT FROM AUTHOR]

ABSTRACT: Urine output and urinary urea-N excretion (UUNe) excretion are critical measures to accurately evaluate N metabolism in lactating dairy cows and environmental concerns related to manure N. The objectives of this study were: (1) to compare estimates of UUNe, urine output, and related variables from 3 pre-established measurement protocols (bladder catheterization, external collection cup, and spot sampling) and from dietary salt supplementation, (2) to study temporal variation in UUNe, urine output, and related variables as affected by measurement protocol, and (3) to evaluate urine specific gravity as a predictor of urine output. Twelve multiparous Holstein cows were used in a split-plot, Latin square design. Cows were randomly assigned to a diet (main plot) containing either 0.7% or 1.6% NaCl (DM basis) and then assigned to a sequence of 3 protocols (subplot) in a balanced 3 × 3 Latin square with 14-d period. For each protocol, measurements were conducted every 4 h for 3 consecutive days. Urine output was determined gravimetrically for bladder catheterization and external collection cup or based on measured cow BW, measured urinary creatinine concentration, and the assumed creatinine excretion of 29 mg/kg BW per day for spot sampling. Urine specific gravity was measured by refractometry. When averaged over a 3-d measurement period and compared with bladder catheterization, spot sampling underestimated urine output (6.8 kg/d; 20%) and UUNe (26 g/d; 13%) but exhibited greater concentration of urinary urea-N (+58 mg/dL; 10%). There were no differences in any measurements determined via bladder catheterization or external cup device protocols, except for urine output that tended to be 3.7 kg/d lower for collection cup compared with bladder catheterization. The 2 gravimetric protocols yielded lower urinary creatinine concentration than spot sampling (64.7 vs. 88.1 mg/dL) and lower creatinine excretion (25.3 mg/kg BW per day) than the value of 29 mg/kg BW per day generally assumed in the spot sampling protocol. Salt supplementation tended to increase urine output (+5.2 kg/d) and decrease urinary urea-N concentration (−93 mg/dL), urinary creatinine concentration (−9.5 mg/dL), milk protein concentration (−0.19 percentage unit) and milk protein yield (−70 g/d). There was greater temporal variation of urine output when measured via the collection cup compared with bladder catheterization in the first 2 d but not the third day of sampling, suggesting that an extended period of adaptation might have improved data quality of the collection cup protocol. The R2 of the linear regression to predict urine output with urine specific gravity was 67%, 73%, and 32% for bladder catheterization, collection cup, and spot sampling, respectively. In this study, spot sampling underestimated both urine output and UUNe, but UUNe determination did not differ between external collection cup and bladder catheterization. However, our data suggested the need to investigate the adaptation protocol, required days of measurements and the conversion of urine mass to urine volume to improve accuracy and precision of urine collection protocols.

Acute kidney injury (AKI) is one of the most common complications for critically ill patients with cirrhosis, but it has remained unclear whether urine output fluctuations are associated with the risk of AKI in such patients. Thus, we explored the influence of 24-h urine-output trajectory on AKI in patients with cirrhosis through latent category trajectory modeling. This retrospective cohort study examined patients with cirrhosis using the MIMIC-IV database. Changes in the trajectories of urine output within 24 h after admission to the intensive care unit (ICU) were categorized using latent category trajectory modeling. The outcome examined was the occurrence of AKI during ICU hospitalization. The risk of AKI in patients with different trajectory classes was explored using the cumulative incidence function (CIF) and the Fine-Gray model with the sub-distribution hazard ratio (SHR) and the 95% confidence interval (CI) as size effects. The study included 3,562 critically ill patients with cirrhosis, of which 2,467 (69.26%) developed AKI during ICU hospitalization. The 24-h urine-output trajectories were split into five classes (Classes 1–5). The CIF curves demonstrated that patients with continuously low urine output (Class 2), a rapid decline in urine output after initially high levels (Class 3), and urine output that decreased slowly and then stabilized at a lower level (Class 4) were at higher risk for AKI than those with consistently moderate urine output (Class 1). After fully adjusting for various confounders, Classes 2, 3, and 4 were associated with a higher risk of AKI compared with Class 1, and the respective SHRs (95% CIs) were 2.56 (1.87–3.51), 1.86 (1.34–2.59), and 1.83 1.29–2.59). The 24-h urine-output trajectory is significantly associated with the risk of AKI in critically ill patients with cirrhosis. More attention should be paid to the dynamic nature of urine-output changes over time, which may help guide early intervention and improve patients' prognoses. [ABSTRACT FROM AUTHOR]

Abstract Background Although the present diagnosis of acute kidney injury (AKI) involves measurement of acute increases in serum creatinine (SC) and reduced urine output (UO), measurement of UO is underutilized for diagnosis of AKI in clinical practice. The purpose of this investigation was to conduct a systematic literature review of published studies that evaluate both UO and SC in the detection of AKI to better understand incidence, healthcare resource use, and mortality in relation to these diagnostic measures and how these outcomes may vary by population subtype. Methods The systematic literature review was performed following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) checklist. Data were extracted from comparative studies focused on the diagnostic accuracy of UO and SC, relevant clinical outcomes, and resource usage. Quality and validity were assessed using the National Institute for Health and Care Excellence (NICE) single technology appraisal quality checklist for randomized controlled trials and the Newcastle–Ottawa Quality Assessment Scale for observational studies. Results A total of 1729 publications were screened, with 50 studies eligible for inclusion. A majority of studies (76%) used the Kidney Disease: Improving Global Outcomes (KDIGO) criteria to classify AKI and focused on the comparison of UO alone versus SC alone, while few studies analyzed a diagnosis of AKI based on the presence of both UO and SC, or the presence of at least one of UO or SC indicators. Of the included studies, 33% analyzed patients treated for cardiovascular diseases and 30% analyzed patients treated in a general intensive care unit. The use of UO criteria was more often associated with increased incidence of AKI (36%), than was the application of SC criteria (21%), which was consistent across the subgroup analyses performed. Furthermore, the use of UO criteria was associated with an earlier diagnosis of AKI (2.4–46.0 h). Both diagnostic modalities accurately predicted risk of AKI-related mortality. Conclusions Evidence suggests that the inclusion of UO criteria provides substantial diagnostic and prognostic value to the detection of AKI.

• According to the manufacturer, an AKIRisk Score value of ≥0.3 identifies patients at high risk for AKI. • Crystalloid cardioplegia may induce high urine output in the hours after cardiac surgery. • There is a significant inverse relationship between urine output and AKIRisk Score. • AKIRisk Score thresholds may require adjustment for urine output. • Early serum creatinine may be superior to AKIRisk Score in predicting subsequent AKI development. Previous studies in other settings suggested that urine output (UO) might affect NephroCheck predictive value. We investigated the correlation between NephroCheck and UO in cardiac surgery patients. Post hoc analysis of a multicenter study. University hospital. Patients who underwent cardiac surgery using cardiopulmonary bypass (CPB) and crystalloid cardioplegia. All patients underwent NephroCheck testing 4 hours after CPB discontinuation. The primary outcome was the correlation between UO, NephroCheck results, and acute kidney injury (AKI, defined according to Kidney Disease: Improving Global Outcomes). Of 354 patients, 337 were included. Median NephroCheck values were 0.06 (ng/mL)2/1,000) for the overall population and 0.15 (ng/mL)2/1,000) for patients with moderate to severe AKI. NephroCheck showed a significant inverse correlation with UO (ρ = −0.17; p = 0.002) at the time of measurement. The area under the receiver characteristic curve (AUROC) for NephroCheck was 0.60 (95% confidence interval [CI], 0.54–0.65), whereas for serum creatinine was 0.82 (95% CI, 0.78–0.86; p < 0.001). When limiting the analysis to the prediction of moderate to severe AKI, NephroCheck had a AUROC of 0.82 (95% CI, 0.77 to 0.86; p<0.0001), while creatinine an AUROC of 0.83 (95% CI, 0.79–0.87; p = 0.001). NephroCheck measured 4 hours after the discontinuation from the CPB predicts moderate to severe AKI. However, a lower threshold may be necessary in patients undergoing cardiac surgery with CPB. Creatinine measured at the same time of the test remains a reliable marker of subsequent development of renal failure. [Display omitted] [ABSTRACT FROM AUTHOR]

Background: Although the present diagnosis of acute kidney injury (AKI) involves measurement of acute increases in serum creatinine (SC) and reduced urine output (UO), measurement of UO is underutilized for diagnosis of AKI in clinical practice. The purpose of this investigation was to conduct a systematic literature review of published studies that evaluate both UO and SC in the detection of AKI to better understand incidence, healthcare resource use, and mortality in relation to these diagnostic measures and how these outcomes may vary by population subtype. Methods: The systematic literature review was performed following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) checklist. Data were extracted from comparative studies focused on the diagnostic accuracy of UO and SC, relevant clinical outcomes, and resource usage. Quality and validity were assessed using the National Institute for Health and Care Excellence (NICE) single technology appraisal quality checklist for randomized controlled trials and the Newcastle–Ottawa Quality Assessment Scale for observational studies. Results: A total of 1729 publications were screened, with 50 studies eligible for inclusion. A majority of studies (76%) used the Kidney Disease: Improving Global Outcomes (KDIGO) criteria to classify AKI and focused on the comparison of UO alone versus SC alone, while few studies analyzed a diagnosis of AKI based on the presence of both UO and SC, or the presence of at least one of UO or SC indicators. Of the included studies, 33% analyzed patients treated for cardiovascular diseases and 30% analyzed patients treated in a general intensive care unit. The use of UO criteria was more often associated with increased incidence of AKI (36%), than was the application of SC criteria (21%), which was consistent across the subgroup analyses performed. Furthermore, the use of UO criteria was associated with an earlier diagnosis of AKI (2.4–46.0 h). Both diagnostic modalities accurately predicted risk of AKI-related mortality. Conclusions: Evidence suggests that the inclusion of UO criteria provides substantial diagnostic and prognostic value to the detection of AKI. [ABSTRACT FROM AUTHOR]

Background: Acute kidney injury (AKI) is a common comorbidity in critically ill children and is associated with an increased risk of morbidity and mortality in children with nephrotic syndrome. The etiology of AKI in nephrotic syndrome is complex and multifactorial. Aims and Objectives: To determine the proportion, risk factors, and outcomes of patients with AKI in children hospitalized with nephrotic syndrome. Materials and Methods: This cross-sectional study was done on children between 1 month and 14 years of age attending the pediatric department for 1 year from October 2020 to June 15, 2022. Detailed history, physical examination, and investigations were done in children with nephrotic syndrome as per pro forma. Information was collected on demographic variables, vital signs, anthropometry, diagnosis, comorbidities, therapies, presence of hypovolemia, sepsis or shock, use of diuretics or nephrotoxic medications, need for oxygen, mechanical ventilation, vasopressors or renal replacement therapy, length of hospital stay, and outcome at discharge. For those children having AKI, clinical outcomes were measured in terms of duration of hospital stay, recovery of S.creatinine, and urine output. Results: A total of 64 patients with nephrotic syndrome were enrolled in this study. Fifteen patients had AKI (23.4%) among children with nephrotic syndrome. The most common etiology being sepsis accounting for 4 out of 15 (26.7%) of total cases followed by acute respiratory distress syndrome (13.3%), nephrotoxic medications (13.3%), renal parenchymal disease (13.3%), Post-streptococcal glomerulonephritis (13.3% each) and Sickle cell disease with nephritis and acute fulminant hepatitis (6.7%). There was significantly more mortality among subjects with stage 2 (14.3%) and 3 (14.3%) kidney disease. Conclusion: AKI is common in our children with nephrotic syndrome and the main risk factors of AKI include sepsis, gross hematuria, urinary tract infections, peritonitis, and exposure to potentially nephrotoxic medications. There is a need to identify the patients with nephrotic syndrome at risk of AKI and apply strategies to prevent AKI in focused at-risk groups.

Background Acute kidney injury (AKI) is one of the most common complications for critically ill patients with cirrhosis, but it has remained unclear whether urine output fluctuations are associated with the risk of AKI in such patients. Thus, we explored the influence of 24-h urine-output trajectory on AKI in patients with cirrhosis through latent category trajectory modeling.Materials and Methods This retrospective cohort study examined patients with cirrhosis using the MIMIC-IV database. Changes in the trajectories of urine output within 24 h after admission to the intensive care unit (ICU) were categorized using latent category trajectory modeling. The outcome examined was the occurrence of AKI during ICU hospitalization. The risk of AKI in patients with different trajectory classes was explored using the cumulative incidence function (CIF) and the Fine-Gray model with the sub-distribution hazard ratio (SHR) and the 95% confidence interval (CI) as size effects.Results The study included 3,562 critically ill patients with cirrhosis, of which 2,467 (69.26%) developed AKI during ICU hospitalization. The 24-h urine-output trajectories were split into five classes (Classes 1–5). The CIF curves demonstrated that patients with continuously low urine output (Class 2), a rapid decline in urine output after initially high levels (Class 3), and urine output that decreased slowly and then stabilized at a lower level (Class 4) were at higher risk for AKI than those with consistently moderate urine output (Class 1). After fully adjusting for various confounders, Classes 2, 3, and 4 were associated with a higher risk of AKI compared with Class 1, and the respective SHRs (95% CIs) were 2.56 (1.87–3.51), 1.86 (1.34–2.59), and 1.83 1.29–2.59).Conclusions The 24-h urine-output trajectory is significantly associated with the risk of AKI in critically ill patients with cirrhosis. More attention should be paid to the dynamic nature of urine-output changes over time, which may help guide early intervention and improve patients’ prognoses.

Acute kidney injury (AKI) is defined by an increase in plasma creatinine or by the installation of a diuresis <0.5 ml/kg per hour. Rapid decrease in glomerular filtration rate (GFR) over extended periods (several hours) is necessary before an increase in plasma creatinine occurs. The latter is late, and even minor increases in creatinine indicate a significant decrease in glomerular filtration rate. Clinical suspicion along with early recognition and management are successive pathways for optimal AKI care. For this reason, it is important to implement a management plan as soon as possible for any patient developing AKI, to prevent and reduce the risk of kidney damage in the long term, because AKI has significant morbidity and mortality if not treated in time. [ABSTRACT FROM AUTHOR]

Background: Acute kidney injury (AKI) is a common comorbidity in critically ill children and is associated with an increased risk of morbidity and mortality in children with nephrotic syndrome. The etiology of AKI in nephrotic syndrome is complex and multifactorial. Aims and Objectives: To determine the proportion, risk factors, and outcomes of patients with AKI in children hospitalized with nephrotic syndrome. Materials and Methods: This cross-sectional study was done on children between 1 month and 14 years of age attending the pediatric department for 1 year from October 2020 to June 15, 2022. Detailed history, physical examination, and investigations were done in children with nephrotic syndrome as per pro forma. Information was collected on demographic variables, vital signs, anthropometry, diagnosis, comorbidities, therapies, presence of hypovolemia, sepsis or shock, use of diuretics or nephrotoxic medications, need for oxygen, mechanical ventilation, vasopressors or renal replacement therapy, length of hospital stay, and outcome at discharge. For those children having AKI, clinical outcomes were measured in terms of duration of hospital stay, recovery of S.creatinine, and urine output. Results: A total of 64 patients with nephrotic syndrome were enrolled in this study. Fifteen patients had AKI (23.4%) among children with nephrotic syndrome. The most common etiology being sepsis accounting for 4 out of 15 (26.7%) of total cases followed by acute respiratory distress syndrome (13.3%), nephrotoxic medications (13.3%), renal parenchymal disease (13.3%), Post-streptococcal glomerulonephritis (13.3% each) and Sickle cell disease with nephritis and acute fulminant hepatitis (6.7%). There was significantly more mortality among subjects with stage 2 (14.3%) and 3 (14.3%) kidney disease. Conclusion: AKI is common in our children with nephrotic syndrome and the main risk factors of AKI include sepsis, gross hematuria, urinary tract infections, peritonitis, and exposure to potentially nephrotoxic medications. There is a need to identify the patients with nephrotic syndrome at risk of AKI and apply strategies to prevent AKI in focused atrisk groups. [ABSTRACT FROM AUTHOR]

Introduction: Low cardiac output and hypovolemia are candidate macrocirculatory mechanisms explanatory of de novo anuria in intensive care unit (ICU) patients undergoing continuous renal replacement therapy (CRRT). We aimed to determine the hemodynamic parameters and CRRT settings associated with the longitudinal course of UO during CRRT. Methods: This is an ancillary analysis of the PRELOAD CRRT observational, single-center study (NCT03139123). Enrolled adult patients had severe acute kidney injury treated with CRRT for less than 24 h and were monitored with a calibrated continuous cardiac output monitoring device. Hemodynamics (including stroke volume index [SVI] and preload-dependence, identified by continuous cardiac index variation during postural maneuvers), net ultrafiltration (UFNET), and UO were reported 4-hourly, over 7 days. Two study groups were defined at inclusion: non-anuric participants if the cumulative 24 h UO at inclusion was ≥0.05 mL kg−1 h−1, and anuric otherwise. Quantitative data were reported by its median [interquartile range]. Results: Forty-two patients (age 68 [58–76] years) were enrolled. At inclusion, 32 patients (76%) were not anuric. During follow-up, UO decreased significantly in non-anuric patients, with 25/32 (78%) progressing to anuria within 19 [10–50] hours. Mean arterial pressure (MAP) and UFNET did not significantly differ between study groups during follow-up, while SVI and preload-dependence were significantly associated with the interaction of study group and time since inclusion. Higher UFNET flow rates were significantly associated with higher systemic vascular resistances and lower cardiac output during follow-up. Multivariate analyses showed that (1) lower UO was significantly associated with lower SVI, lower MAP, and preload-independence; and (2) higher UFNET was significantly associated with lower UO. Conclusions: In ICU patients treated with CRRT, those without anuria showed a rapid loss of diuresis after CRRT initiation. Hemodynamic indicators of renal perfusion and effective volemia were the principal determinants of UO during follow-up, in relation with the hemodynamic impact of UFNET setting. [ABSTRACT FROM AUTHOR]

Abstract Background Ulinastatin, an anti-inflammatory and antioxidant trypsin inhibitor, has shown potential in mitigating acute kidney injury (AKI) and reducing serum creatinine levels after various surgeries. This retrospective study aimed to evaluate the effects of ulinastatin on AKI in patients undergoing off-pump coronary artery bypass (OPCAB) surgery. Methods We hypothesized that the administration of ulinastatin could prevent AKI in OPCAB. Electrical medical records were reviewed to identify OPCAB patients between January 2015 and June 2020. The utilization of ulinastatin was randomly determined and applied during this period. Acute kidney injury was defined according to the KDIGO guideline, and its incidence was compared between the ulinastatin administration group and the control group. To investigate the effect of ulinastatin on renal function, multivariate logistic regression analysis was used to calculate propensity scores for each group. Results A total 454 OPCAB were performed, and after following inclusion and exclusion process, 100 patients were identified in the ulinastatin group and 303 patients in the control group. Using 1:2 propensity score matching, we analyzed 100 and 200 patients in the ulinastatin and control groups. The incidence of AKI was similar between the groups (2.5% for the control group, 2.0% for the ulinastatin group, p > 0.999). However, the serum creatinine value on the first post-operative day were significantly lower in the ulinastatin group compared to the control group (0.774 ± 0.179 mg/dL vs 0.823 ± 0.216 mg/dL, P = 0.040), while no significant differences were observed for the other time points (P > 0.05). The length of ICU stay day was significantly shorter in the ulinastatin group (2.91 ± 2.81 day vs 5.22 ± 7.45 day, respectively, P

Acute kidney injury (AKI) in children is a critical medical condition characterized by a sudden decline in kidney function. This article provides a comprehensive overview of AKI in pediatric populations, exploring its pathophysiology, the role of various drugs and the long-term implications for kidney health. Key topics include oliguria, anuria, urine output, hypervolemia and the interactions among them, as well as role of diuretic nephrotoxicity and the glomerular filtration rate. Concepts of electrolytes, acid–base balance and renal perfusion assessment are presented. Basic principles of intensive care unit (ICU) management, renal replacement therapy and the association with multiorgan failure are described. Additionally, the article discusses the potential long-term outcomes of AKI, including the risk of chronic kidney disease, hypertension and proteinuria.

Background: Ulinastatin, an anti-inflammatory and antioxidant trypsin inhibitor, has shown potential in mitigating acute kidney injury (AKI) and reducing serum creatinine levels after various surgeries. This retrospective study aimed to evaluate the effects of ulinastatin on AKI in patients undergoing off-pump coronary artery bypass (OPCAB) surgery. Methods: We hypothesized that the administration of ulinastatin could prevent AKI in OPCAB. Electrical medical records were reviewed to identify OPCAB patients between January 2015 and June 2020. The utilization of ulinastatin was randomly determined and applied during this period. Acute kidney injury was defined according to the KDIGO guideline, and its incidence was compared between the ulinastatin administration group and the control group. To investigate the effect of ulinastatin on renal function, multivariate logistic regression analysis was used to calculate propensity scores for each group. Results: A total 454 OPCAB were performed, and after following inclusion and exclusion process, 100 patients were identified in the ulinastatin group and 303 patients in the control group. Using 1:2 propensity score matching, we analyzed 100 and 200 patients in the ulinastatin and control groups. The incidence of AKI was similar between the groups (2.5% for the control group, 2.0% for the ulinastatin group, p > 0.999). However, the serum creatinine value on the first post-operative day were significantly lower in the ulinastatin group compared to the control group (0.774 ± 0.179 mg/dL vs 0.823 ± 0.216 mg/dL, P = 0.040), while no significant differences were observed for the other time points (P > 0.05). The length of ICU stay day was significantly shorter in the ulinastatin group (2.91 ± 2.81 day vs 5.22 ± 7.45 day, respectively, P < 0.001). Conclusions: Ulinastatin did not have a significant effect on the incidence of AKI; it demonstrated the ability to reduce post-operative serum creatine levels at first post-operative day and shorten the length of ICU stay. [ABSTRACT FROM AUTHOR]

Background: Acute kidney injury (AKI) is a frequent complication of children admitted to the paediatric intensive care unit. One key management modality of AKI is the use of diuretics to reduce fluid overload. Aminophylline, a drug that is well known for its use in the treatment of bronchial asthma, is also purported to have diuretic effects on the kidneys. This retrospective cohort study assesses the effect of aminophylline in critically ill children with AKI. Methods: A retrospective chart review of children admitted to the paediatric intensive care unit of the Red Cross War Memorial Children's Hospital (RCWMCH) with AKI who received aminophylline (from 2012 to June 2018) was carried out. Data captured and analyzed included demographics, underlying disease conditions, medications, urine output, fluid balance, and kidney function. Results: Data from thirty-four children were analyzed. Urine output increased from a median of 0.4 mls/kg/hr [IQR: 0.1, 1.1] at six hours prior to aminophylline administration to 0.6 mls/kg/hr [IQR: 0.2, 1.9] at six hours and 1.6 mls/kg/hr [IQR:0.2, 4.2] at twenty-four hours post aminophylline therapy. The median urine output significantly varied across the age groups over the 24-h time period post-aminophylline, with the most response in the neonates. There was no significant change in serum creatinine levels six hours post-aminophylline administration [109(IQR: 77, 227)—125.5(IQR: 82, 200) micromole/l] P-value = 0.135. However, there were significant age-related changes in creatinine levels at six hours post-aminophylline therapy. Conclusions: Aminophylline increases urine output in critically ill children with AKI. [ABSTRACT FROM AUTHOR]

Around 10% of critically ill patients suffer acute kidney injury (AKI) requiring kidney replacement therapy (KRT), with a mortality rate approaching 50%. Although most survivors achieve sufficient renal recovery to be weaned from KRT, there are no recognized guidelines on the optimal period for weaning from KRT. A systematic review was conducted using a peer-reviewed strategy, combining themes of KRT (intermittent hemodialysis, CKRT: continuous veno-venous hemo/dialysis/filtration/diafiltration, sustained low-efficiency dialysis/filtration), factors predictive of successful weaning (defined as a prolonged period without new KRT) and patient outcomes. Our research resulted in studies, all observational, describing clinical and biological parameters predictive of successful weaning from KRT. Urine output prior to KRT cessation is the most studied variable and the most widely used in practice. Other predictive factors, such as urinary urea and creatinine and new urinary and serum renal biomarkers, including cystatin C and neutrophil gelatinase-associated lipocalin (NGAL), were also analyzed in the light of recent studies. This review presents the rationale for early weaning from KRT, the parameters that can guide it, and its practical modalities. Once the patient's clinical condition has stabilized and volume status optimized, a diuresis greater than 500 mL/day should prompt the intensivist to consider weaning. Urinary parameters could be useful in predicting weaning success but have yet to be validated. [ABSTRACT FROM AUTHOR]

Objective: To determine the frequency of acute kidney injury (AKI) in neonates presenting with birth asphyxia. Study Design: Cross-sectional study. Setting: Department of Pediatrics, National Institute of Child Health, Karachi. Period: December 2022 to May 2023. Material & Methods: A total of 159 neonates of both gender, aged between 7-28 days and having birth asphyxia were analyzed. Demographic features were recorded. The blood sample was collected in a sterile manner using 5 ml syringe and sent to the institutional laboratory for serum creatinine and electrolyte analysis. The frequency of AKI was noted. Results: In a total of 159 neonates, 95 (59.1%) were boys, The mean baseline serum urea and creatinine were 33.5±32.1 and 0.83±0.62 mg/dl respectively. AKI was noted in 65 (40.9%) neonates. Girls (p=0.035), relatively lower occipital frontal circumference (p=0.004), normal vaginal delivery (p<0.001), history of seizures (p<0.001), abnormal USG KUB (p<0.001), poor conscious level (p<0.001), higher birth asphyxia grading (p<0.001) and poor urine output (p<0.001) were linked with AKI. Mean baseline serum urea levels and serum creatinine levels were significantly raised among neonates who had AKI. Conclusion: The frequency of acute kidney injury among neonates having perinatal asphyxia was high. AKI was noted to have significant association with female gender, relatively lower occipital frontal circumference, normal vaginal delivery, history of seizures, abnormal ultrasonography findings, poor conscious level, higher birth asphyxia grading, and poor urine output at the time of admission. [ABSTRACT FROM AUTHOR]

Rationale & objectiveAcute kidney injury treated with kidney replacement therapy (AKI-KRT) occurs frequently in critically ill patients with coronavirus disease 2019 (COVID-19). We examined the clinical factors that determine kidney recovery in this population.Study designMulticenter cohort study.Setting & participants4,221 adults not receiving KRT who were admitted to intensive care units at 68 US hospitals with COVID-19 from March 1 to June 22, 2020 (the "ICU cohort"). Among these, 876 developed AKI-KRT after admission to the ICU (the "AKI-KRT subcohort").ExposureThe ICU cohort was analyzed using AKI severity as the exposure. For the AKI-KRT subcohort, exposures included demographics, comorbidities, initial mode of KRT, and markers of illness severity at the time of KRT initiation.OutcomeThe outcome for the ICU cohort was estimated glomerular filtration rate (eGFR) at hospital discharge. A 3-level outcome (death, kidney nonrecovery, and kidney recovery at discharge) was analyzed for the AKI-KRT subcohort.Analytical approachThe ICU cohort was characterized using descriptive analyses. The AKI-KRT subcohort was characterized with both descriptive analyses and multinomial logistic regression to assess factors associated with kidney nonrecovery while accounting for death.ResultsAmong a total of 4,221 patients in the ICU cohort, 2,361 (56%) developed AKI, including 876 (21%) who received KRT. More severe AKI was associated with higher mortality. Among survivors, more severe AKI was associated with an increased rate of kidney nonrecovery and lower kidney function at discharge. Among the 876 patients with AKI-KRT, 588 (67%) died, 95 (11%) had kidney nonrecovery, and 193 (22%) had kidney recovery by the time of discharge. The odds of kidney nonrecovery was greater for lower baseline eGFR, with ORs of 2.09 (95% CI, 1.09-4.04), 4.27 (95% CI, 1.99-9.17), and 8.69 (95% CI, 3.07-24.55) for baseline eGFR 31-60, 16-30, ≤15 mL/min/1.73 m2, respectively, compared with eGFR > 60 mL/min/1.73 m2. Oliguria at the time of KRT initiation was also associated with nonrecovery (ORs of 2.10 [95% CI, 1.14-3.88] and 4.02 [95% CI, 1.72-9.39] for patients with 50-499 and

Urine output is an important indicator of renal function. In hospitals, urine is collected using a catheter connected to a urine collection bag that has volume gradation markings. This type of visual measurement has low levels of accuracy and is labor-intensive. This paper developed an Internet-of-Things enabled system that continuously monitors the urine volume collected via the urine collection system. The device is built utilizing a strain gauge load cell, an integrated circuit that contains an amplifier, analog-to-digital converter, and a WiFi-enabled microcontroller. The data is sent via wireless networking to a data collection and analysis server, which provides accurate analyses of urine output. A mobile application utilizing the Blynk.io system is used to display the data. This device and mobile application were built at a minimal cost of 26 USD. The device has been tested multiple times and reported urine output accurately, with minimal difference between actual versus measured volumes. In the future, further development of this device can provide hospitals and physicians worldwide with easy access to affordable, accurate, and real-time urine measurement, which would translate into better, life-saving medical care.

Background Due to the convenience of serum creatinine (SCr) monitoring and the relative complexity of urine output (UO) monitoring, most studies have predicted acute kidney injury (AKI) only based on SCr criteria. This study aimed to compare the differences between SCr alone and combined UO criteria in predicting AKI. Methods We applied machine learning methods to evaluate the performance of 13 prediction models composed of different feature categories on 16 risk assessment tasks (half used only SCr criteria, half used both SCr and UO criteria). The area under receiver operator characteristic curve (AUROC), the area under precision recall curve (AUPRC) and calibration were used to assess the prediction performance. Results In the first week after ICU admission, the prevalence of any AKI was 29% under SCr criteria alone and increased to 60% when the UO criteria was combined. Adding UO to SCr criteria can significantly identify more AKI patients. The predictive importance of feature types with and without UO was different. Using only laboratory data maintained similar predictive performance to the full feature model under only SCr criteria [e.g. for AKI within the 48-h time window after 1 day of ICU admission, AUROC (95% confidence interval) 0.83 (0.82, 0.84) vs 0.84 (0.83, 0.85)], but it was not sufficient when the UO was added [corresponding AUROC (95% confidence interval) 0.75 (0.74, 0.76) vs 0.84 (0.83, 0.85)]. Conclusions This study found that SCr and UO measures should not be regarded as equivalent criteria for AKI staging, and emphasizes the importance and necessity of UO criteria in AKI risk assessment. [ABSTRACT FROM AUTHOR]

Background: Few works have analyzed factors associated with urine output in ADPKD patients taking tolvaptan (TVP). Methods: We selected 24-h urine samples from ADPKD patients treated with TVP. Urine osmolality/creatinine ratio was used as estimator of urinary osmolar load. Results: We included 127 urine samples from 61 patients. After TVP, urine output doubled with a parallel reduction in urine solute concentration. However, when expressed as urine solute/creatinine ratios, no significant changes were observed. Daily osmolar load and osmolality/creatinine ratio did not change significantly. Before TVP, urine output was positively correlated with body weight and urine osmolality/creatinine ratio and negatively with eGFR, urine morning osmolality, and 24-h urine-calculated osmolality. After TVP, urine output was positively correlated with body weight, eGFR and negatively with age. There was a poor correlation with urine-calculated osmolality. We constructed a predictor model using mixed-effects modeling and we found that urine output was related to lower age, higher body weight, higher eGFR, and greater doses of TVP. When body weight was removed, urine output was also related to male sex and a higher daily osmolar excretion. Equation of prediction was: Urine output (mL/day) = 2771–52.9 × Age (years) + 58.4 × Weight (kg) + 18.7 × eGFR (mL/min) + 870 (if TVP = 90/30 mg) + 517 (if TVP = 60/30 mg). Conclusion: Patients taking TVP will undergo an increase about twice in urine production from baseline. Greater doses of TVP cause a progressive increase in urine production. GFR, age, and body weight are the main predictors of future urine output in patients taking TVP. [ABSTRACT FROM AUTHOR]

Objectives: Urine output is used to evaluate fluid status and is an important marker for acute kidney injury (AKI). Our primary aim was to validate a new automatic urine output monitoring device by comparison to the current practice – the standard urometer. Methods: We conducted a prospective observational study in three ICUs. Urine flow measurements by Serenno Medical Automatic urine output measuring device (Serenno Medical, Yokneam, Israel) were compared to standard urometer readings taken automatically at 5-minutes intervals by a camera, and to hourly urometer readings by the nurses, both over 1 to 7 days. Our primary outcome was the difference between urine flow assessed by the Serenno device and reference camera-derived measurements (Camera). Our secondary outcome was the difference between urine flow assessed by the Serenno device and hourly nursing assessments (Nurse), and detection of oliguria. Results: Thirty-seven patients completed the study, with 1,306 h of recording and a median of 25 measurement hours per patient. Bland and Altman analysis comparing the study device to camera measurements demonstrated good agreement, with a bias of -0.4 ml/h and 95% confidence intervals ranging from − 28 to 27ml/h. Concordance was 92%. The correlation between Camera and hourly nursing assessment of urine output was distinctly worse with a bias of 7.2 ml and limits of agreement extending from − 75 to + 107 ml. Severe oliguria (urine output < 0.3 ml/kg/h) lasting 2 h or more was common and observed in 8 (21%) of patients. Among the severe oliguric events lasting more than 3 consecutive hours, 6 (41%) were not detected or documented by the nursing staff. There were no device-related complications. Conclusion: The Serenno Medical Automatic urine output measuring device required minimal supervision, little ICU nursing staff attention, and is sufficiently accurate and precise. In addition to providing continuous assessments of urine output, it was considerably more accurate than hourly nursing assessments. [ABSTRACT FROM AUTHOR]

Urine output (UO) is an important intraoperative parameter that is not yet electronically monitored. We compared an automatic urinometer (AU) based on a smart scale with a manual urinometer (MU). This prospective study investigated the hourly UO of 35 preoperative patients with an indwelling urinary catheter using AU, MU, and cylinder measurements. Data were analyzed using the Bland-Altman method. A questionnaire related to the use of the AU was completed by medical staff (n=25). Compared to the cylinder measurements, the differences in measurements by the AU and the MU were −6.31 ​± ​15.03 ​mL/h (p =0.018) and 20.26 ​± ​26.81 ​mL/h (p =0.001), respectively. The r values for the comparison of cylinder measurements with AU and MU values were 0.985 (p <0.001) and 0.968 (p <0.001), respectively. Bland-Altman analyses showed that cylinder measurements had better agreement with the AU measurements than with the MU measurements. Also, the medical staff reported that the use of the AU was easier to learn than the use of the MU (p <0.001). Compared to the MU values, AU values were noninferior; they had significantly less bias and temporal deviation. Additionally, the medical staff reported that the use of the AU was easier to learn than the use of the MU. [ABSTRACT FROM AUTHOR]

L'insuffisance rénale aiguë (IRA) est une entité pathologique très complexe. La définition de l'IRA a heureusement évolué ces dernières années en faveur d'une certaine harmonisation. Plusieurs scores ont été proposés (RIFLE, AKIN et KDIGO). Ils se basent tous sur une définition dynamique qui prend en compte les variations de créatinine sérique d'une part, et de débit urinaire d'autre part. Ces scores ne sont cependant pas parfaits et certaines limitations sont à souligner. Il n'en reste pas moins qu'ils ont permis d'harmoniser la définition d'IRA et, par là même, de mieux appréhender cette pathologie compliquée. Acute kidney injury (AKI) is a complex pathological status. The definition of AKI has fortunately evolved in the last years on the way of a sort of standardization. Several AKI scores have been proposed (RIFLE, AKIN, and KDIGO). These scores are all dynamic, as they are based on variations of serum creatinine and urine output. Such scores are however not without any limitations that we will discuss in the current article. All in one, these scores have led to a harmonization of the definition of AKI which allows clinicians to better apprehend this complex disease. [ABSTRACT FROM AUTHOR]

Abstract Background Perioperative acute kidney injury (AKI) caused by ischemia–reperfusion (IR) is a significant contributor to mortality and morbidity after major surgery. Furosemide is commonly used in postoperative patients to promote diuresis and reduce tissue edema. However, the effects of furosemide on renal microcirculation, oxygenation and function are poorly understood during perioperative period following ischemic insult. Herein, we investigated the effects of furosemide in rats subjected IR insult. Methods 24 Wistar albino rats were divided into 4 groups, with 6 in each; Sham-operated Control (C), Control + Furosemide (C + F), ischemia/reperfusion (IR), and IR + F. After induction of anesthesia (BL), supra-aortic occlusion was applied to IR and IR + F groups for 45 min followed by ongoing reperfusion for 15 min (T1) and 2 h (T2). Furosemide infusion was initiated simultaneously in the intervention groups after ischemia. Renal blood flow (RBF), vascular resistance (RVR), oxygen delivery (DO2ren) and consumption (VO2ren), sodium reabsorption (TNa+), oxygen utilization efficiency (VO2/TNa+), cortical (CμO2) and medullary (MμO2) microvascular oxygen pressures, urine output (UO) and creatinine clearance (Ccr) were measured. Biomarkers of inflammation, oxidative and nitrosative stress were measured and kidneys were harvested for histological analysis. Results IR significantly decreased RBF, mainly by increasing RVR, which was exacerbated in the IR + F group at T2 (2198 ± 879 vs 4233 ± 2636 dyne/s/cm5, p = 0.07). CμO2 (61.6 ± 6.8 vs 86 ± 6.6 mmHg) and MμO2 (51.1 ± 4.1 vs 68.7 ± 4.9 mmHg, p

Introduction: Preterm babies are a vulnerable population group who are more susceptible to multiple end-organ damage due to an immature immune system and incomplete organogenesis/organ function. There is scanty data on preterm Acute Kidney Injury (AKI) in India. Aim: To investigate the incidence of acute renal failure and the risk factors predisposing preterm babies to renal failure in an inborn at a tertiary care centre in Southern India. Additionally, we aimed to evaluate the usefulness of a biomarker, Neutrophil Gelatinase Associated Lipocalin (NGAL), as both a marker of renal function and a predictor of AKI in preterm babies. Materials and Methods: A cross-sectional study was conducted in the Neonatal Intensive Care Unit (NICU) at Christian Medical College, Vellore, Tamil Nadu, India, between May 2014 and August 2014. The study included babies born <33 weeks of gestation, while those with abnormal antenatal renal scans, major systemic congenital anomalies, and chromosomal anomalies were excluded. Demographic details and clinical features were noted. Weekly monitoring included urine output, assessment of clinical deterioration, details of interventions, unexpected events, and the use of nephrotoxic drugs. Blood samples for serum creatinine and urine samples for NGAL were collected once a week starting from 72 hours of age. The data was statistically analysed using Statistical Package for the Social Sciences (SPSS) software, version 16.0. Descriptive statistics were reported using mean±SD for continuous variables. Repeated measures Analysis of Variance (ANOVA) and Chi-square test/Fisher's-exact test were used for categorical variables. Risk factor analysis was done using log binomial to estimate the Relative Risks (RR), considering values greater than 1 as significant. Results: During the study period, a total of 4823 live births were recorded. Among them, 80 babies had a gestational age <33 weeks (10.14%). One baby was not recruited as the parents did not provide consent, leaving a total of 79 babies included in the study. Five babies did not complete the study (three died and two were discharged against medical advice). The incidence of AKI in babies <32±6 weeks in this study was 10 out of 79 (12.6%). It was higher in babies <28 weeks, with 4 out of 10 (40%) affected, and all 10 babies (100%) weighed less than 1500 gm at birth. Risk factors for AKI included oliguria, Patent Ductus Arteriosus (PDA), nephrotoxic drugs, low APGAR score, mechanical ventilation, Continuous Positive Airway Pressure (CPAP), and abnormal antenatal scans. Urine NGAL was estimated in 30 babies, and it was found that NGAL levels were high in week 1 or rose by week 2 in those with AKI, while creatinine levels increased in week 2 or 3. NGAL was inversely proportional to gestational age and birth weight. Both NGAL rise and creatinine levels were observed in babies with AKI associated with Non-Steroidal Anti-Inflammatory Drugs (NSAIDS), umbilical lines, and asphyxia. Conclusion: The incidence of AKI was found to be 10%. Although NGAL levels were noted to rise earlier than creatinine levels in those with AKI, a definitive cutoff value for NGAL to define AKI could not be calculated. Due to the small study population, the sensitivity and specificity of NGAL could not be determined. [ABSTRACT FROM AUTHOR]

Urine output is an important indicator of renal function. In hospitals, urine is collected using a catheter connected to a urine collection bag that has volume gradation markings. This type of visual measurement has low levels of accuracy and is labor-intensive. This paper developed an Internet-of-Things enabled system that continuously monitors the urine volume collected via the urine collection system. The device is built utilizing a strain gauge load cell, an integrated circuit that contains an amplifier, analog-to-digital converter, and a WiFi-enabled microcontroller. The data is sent via wireless networking to a data collection and analysis server, which provides accurate analyses of urine output. A mobile application utilizing the Blynk.io system is used to display the data. This device and mobile application were built at a minimal cost of 26 USD. The device has been tested multiple times and reported urine output accurately, with minimal difference between actual versus measured volumes. In the future, further development of this device can provide hospitals and physicians worldwide with easy access to affordable, accurate, and real-time urine measurement, which would translate into better, life-saving medical care. [ABSTRACT FROM AUTHOR]

Introduction:Although residual urine output (UOP) is associated with better survival and quality of life in dialysis patients, frequent measurement by 24-hour urine collection is burdensome. We thus sought to examine the association of patients' self-reported residual UOP, as an alternative proxy of measured residual UOP, with mortality risk in a prospective hemodialysis cohort study. Methods:Among 670 hemodialysis patients from the prospective multicenter Malnutrition, Diet, and Racial Disparities in Kidney Disease study, we examined associations of residual UOP, ascertained by patient self-report, with all-cause mortality. Patients underwent protocolized surveys assessing presence and frequency of UOP (absent, every 1-3 days, >1 time per day) every 6 months from 2011 to 2015. We examined associations of baseline and time-varying UOP with mortality using Cox regression. Results:In analyses of baseline UOP, absence of UOP was associated with higher mortality in expanded case-mix adjusted Cox models (ref: presence of UOP): hazard ratio (HR), 1.78 (95% confidence interval [CI], 1.16-2.72). In analyses examining baseline frequency of UOP, point estimates suggested a graded association between lower frequency of UOP and higher mortality, although estimates for UOP every 1 to 3 days did not reach statistical significance (reference: UOP >1 time per day): HR, 1.29 (95% CI, 0.82-2.05) and HR, 1.97 (95% CI, 1.24-3.12) for UOP every 1 to 3 days and absence of UOP, respectively. Similar findings were observed in analyses of time-varying UOP. Conclusion:In hemodialysis patients, there is a graded association between lower frequency of self-reported UOP and higher mortality. Further studies are needed to determine the clinical impact of more frequent assessment of residual UOP using self-reported methods.

Background: Perioperative acute kidney injury (AKI) caused by ischemia–reperfusion (IR) is a significant contributor to mortality and morbidity after major surgery. Furosemide is commonly used in postoperative patients to promote diuresis and reduce tissue edema. However, the effects of furosemide on renal microcirculation, oxygenation and function are poorly understood during perioperative period following ischemic insult. Herein, we investigated the effects of furosemide in rats subjected IR insult. Methods: 24 Wistar albino rats were divided into 4 groups, with 6 in each; Sham-operated Control (C), Control + Furosemide (C + F), ischemia/reperfusion (IR), and IR + F. After induction of anesthesia (BL), supra-aortic occlusion was applied to IR and IR + F groups for 45 min followed by ongoing reperfusion for 15 min (T1) and 2 h (T2). Furosemide infusion was initiated simultaneously in the intervention groups after ischemia. Renal blood flow (RBF), vascular resistance (RVR), oxygen delivery (DO2ren) and consumption (VO2ren), sodium reabsorption (TNa+), oxygen utilization efficiency (VO2/TNa+), cortical (CμO2) and medullary (MμO2) microvascular oxygen pressures, urine output (UO) and creatinine clearance (Ccr) were measured. Biomarkers of inflammation, oxidative and nitrosative stress were measured and kidneys were harvested for histological analysis. Results: IR significantly decreased RBF, mainly by increasing RVR, which was exacerbated in the IR + F group at T2 (2198 ± 879 vs 4233 ± 2636 dyne/s/cm5, p = 0.07). CμO2 (61.6 ± 6.8 vs 86 ± 6.6 mmHg) and MμO2 (51.1 ± 4.1 vs 68.7 ± 4.9 mmHg, p < 0.05) were both reduced after IR and did not improve by furosemide. Moreover, VO2/TNa+ increased in the IR + F group at T2 with respect to the IR group (IR: 3.3 ± 2 vs IR + F: 8.2 ± 10 p = 0.07) suggesting a possible deterioration of oxygen utilization. Ccr did not change, but plasma creatinine increased significantly in IR + F groups. Histopathology revealed widespread damage both in the cortex and medulla in IR, IR + F and C + F groups. Conclusion: Renal microvascular oxygenation, renal function, renal vascular resistance, oxygen utilization and damage were not improved by furosemide administration after IR insult. Our study suggests that furosemide may cause additional structural and functional impairment to the kidney following ischemic injury and should be used with caution. [ABSTRACT FROM AUTHOR]

The relationship between urine output (UO) and in-hospital mortality in patients with sepsis-associated acute respiratory distress syndrome (ARDS) has not been elucidated. The demographic and clinical characteristics of patients from the intensive care unit with sepsis-associated ARDS in the Medical Information Mart for Intensive Care-IV database were collected, and binomial logistic regression was performed to determine whether UO was an independent risk factor for in-hospital death. Using the Logistic Organ Dysfunction System (LODS) and Sequential Organ Failure Assessment (SOFA) as a reference, receiver operating characteristic (ROC) curves were drawn to analyze the efficacy of UO in predicting in-hospital mortality, and the Kaplan-Meier curve was drawn with the optimal cut-off value of the ROC curve. Decision curve analysis (DCA) was performed to assess the clinical net benefit of UO in predicting in-hospital mortality. UO was an independent risk factor for in-hospital mortality in patients with sepsis-associated ARDS. The area under the ROC (AUC) for UO in predicting in-hospital mortality was 0.712, which was comparable to LODS and SOFA. The patients were grouped by the optimal UO cut-off value (1515 mL/day) identified by the ROC curve. The results showed that the median in-hospital survival time for the low-UO group was 20.565 days, and that of the high-UO group was 84.670 days. The risk of in-hospital death of the low-UO group was 3.0792 times that of the high-UO group. DCA showed that when using UO to predict in-hospital mortality, the clinical net benefit was higher than LODS or SOFA at almost all available threshold probabilities, particularly when the threshold probability was between 0.2 and 0.4. As a result, UO showed moderate efficacy in predicting in-hospital mortality, and when used to predict the in-hospital mortality of patients with sepsis-related ARDS, its clinical net benefit was higher than that of LODS or SOFA. [ABSTRACT FROM AUTHOR]

Introduction : Acute kidney injury (AKI) is a common complication in patients undergoing coronary artery bypass graft (CABG) surgery and is associated with significant morbidity and mortality. We investigated the association of urine output (U/O) during cardiopulmonary bypass (CPB) with postoperative AKI in a cohort of patients undergoing elective CABG. Materials and Methods : This single-center retrospective study used data from patients undergoing elective CABG with CPB (March 2015 to March 2020). Demographic data and perioperative information were extracted from the Patients' records. Urine output during CPB and in the first 3 days after surgery was also recorded. Acute kidney injury was defined according to the Acute Kidney Injury Network (AKIN) classification. Spearman's correlation analysis was used to evaluate the relationship between quantitative variables and multiple logistic regression analysis was applied to determine AKI predictors. Results : A total of 532 patients with a mean age of 56.83 ± 7.99 years were analyzed. In the first 48 h after surgery, the incidence of AKI was 18%, of which, 7 (2.7%) patients developed stage II of AKI. There was no significant correlation between U/O during CPB and change in postoperative blood urea nitrogen (BUN) and creatinine. Oliguria during CPB was not observed in any of the patients. Age and duration of bypass were identified as predictors of AKI. Conclusion : In this study, the incidence of AKI was 18% and there was no significant correlation between U/O during CPB and changes in postoperative BUN and creatinine. Age and duration of bypass were independent risk factors of AKI. [ABSTRACT FROM AUTHOR]

Spot determinations of the urine creatinine concentration are widely used as a substitute for 24-h urine collections. Expressed as the amount excreted per gram of creatinine, urine concentrations in a single-voided sample are often used to estimate 24-h excretion rates of protein, sodium, potassium, calcium, magnesium, urea and uric acid. These estimates are predicated on the assumption that daily creatinine excretion equals 1 g (and that a urine creatinine concentration of 100 mg/dL reflects a 1 L 24-h urine volume). Such estimates are invalid if the serum creatinine concentration is rising or falling. In addition, because creatinine excretion is determined by muscle mass, the assumption that 24-h urine creatinine excretion equals 1 g yields a misleading estimate at the extremes of age and body size. In this review, we evaluate seven equations for the accuracy of their estimates of urine volume based on urine creatinine concentrations in actual and idealized patients. None of the equations works well in patients who are morbidly obese or in patients with markedly decreased muscle mass. In other patients, estimates based on a reformulation of the Cockroft–Gault equation are reasonably accurate. A recent study based on this relationship found a high strength of correlation between estimated and measured urine output with chronic kidney disease (CKD) studied in the African American Study of Kidney Disease (AASK) trial and for the patients studied in the CKD Optimal Management with Binders and NictomidE (COMBINE) trial. However, the equation systematically underestimated urine output in the AASK trial. Hence, an intercept was added to account for the bias in the estimated output. A more rigorous equation derived from an ambulatory Swiss population, which includes body mass index and models the non-linear accelerated decline in creatinine excretion with age, could potentially be more accurate in overweight and elderly patients. In addition to extremes of body weight and muscle mass, decreased dietary intake or reduced hepatic synthesis of creatine, a precursor of creatinine or ingestion of creatine supplements will also result in inaccurate estimates. These limitations must be appreciated to rationally use predictive equations to estimate urine volume. If the baseline urine creatinine concentration is determined in a sample of known volume, subsequent urine creatinine concentrations will reveal actual urine output as well as the change in urine output. Given the constraints of the various estimating equations, a single baseline timed collection may be a more useful strategy for monitoring urine volume than entering anthropomorphic data into a calculator. [ABSTRACT FROM AUTHOR]

Background: Humans have been aware of snakebite toxicity since antiquity. Hemotoxic snakebite patients frequently get acute kidney injury (AKI) and require dialysis. Aim: In this study, the early clinical indicators of AKI in patients with snakebites are evaluated. Methods: In this prospective study, 50 patients with hemotoxic snakebite participated. The patients who experienced AKI after being bitten by a snake were identified according to standard guidelines, and the non-invasive clinical characteristics of these individuals were evaluated. The demographic information, clinical symptoms, blood and urine testing, and lapse time (the time span between the snakebite and the injection of anti-venom serum) were all noted and analyzed. Results: Male-female ratio was 1:08, with participants' average age being 41.2+-16 years. AKI developed in 41 patients, and 12% of them needed dialysis. There was a substantial correlation between the lapse time and the development of AKI, as evidenced by the mean lapse of time, which was 10.3046 and 2.5178 hours for patients with and without AKI, respectively (SE = 3.35-0.542). A whole blood clotting time (WBCT) of >20 minutes and dark-brown urine were also independently linked to AKI. The presence of hypotension, local inflammation, bite site hemorrhage, or the amount of anti-venom serum (AVS) administered did not, however, showed a statistically significant correlation (P > 0.05) with the development of AKI. Conclusion: AKI can be expected when hematuria is present, the WBCT is more than 20-minutes, and there is a long delay of time between the bite and the administration of AVS. [ABSTRACT FROM AUTHOR]

Purpose: Assessing fluid output for infants in the neonatal intensive care unit is essential to understanding fluid and electrolyte balance. Wet diaper weights are used as standard practice to quantify fluid output; yet, diaper changes are intrusive and physiologically distressing. Less frequent diaper changes may have physiologic benefits but could alter diaper weights following extended intervals. Methods: This pilot study examined the impact of initial diaper fluid volume, incubator air temperature and humidity, and diaper brand on wet diaper weight over time. Baseline fluid volume was instilled, and then diapers were placed in a neonatal incubator. Wet diaper weight was assessed longitudinally to determine changes in fluid volume over time. A factorial design with repeated measures (baseline, 3 hours, and 6 hours) was used to explore the effects of diaper brand (brand 1 vs brand 2), baseline fluid volume (3 mL vs 5 mL), and incubator temperature (28°C vs 36°C) and humidity (40% vs 80%) on the trajectory of weight in 80 diapers. Results: Wet diaper weight was significantly reduced over 6 hours (P <.005). However, wet diaper weight increased in 80% humidity, but decreased in the 40% humidity over time (P <.0001). Baseline fluid volume, incubator temperature, and diaper brand did not influence wet diaper weight over time (all P >.05). Implications: Understanding environmental factors that influence the trajectory of wet diaper weight may support clinicians in optimizing the interval for neonatal diaper changes to balance the impact of intrusive care with need to understand fluid volume loss. [ABSTRACT FROM AUTHOR]

Background: Acute kidney injury (AKI) occurs commonly after major surgery and is correlated with increased in-hospital morbidity and mortality. There is no consensus on whether intraoperative oliguria affects postoperative AKI. We conducted a meta-analysis to systematically assess the correlation of intraoperative oliguria with postoperative AKI. Methods: PubMed, Embase, Web of Science, and Cochrane Library databases were searched to identify reports on the relationship between intraoperative oliguria and postoperative AKI. Quality was assessed using the Newcastle-Ottawa Scale. The primary outcomes were the unadjusted and multivariate-adjusted odds ratios (ORs) for intraoperative oliguria to correlate with postoperative AKI. The secondary outcomes included intraoperative urine output in the AKI and non-AKI groups, the demand for postoperative renal replacement therapy (RRT), in-hospital mortality, and length of hospital stay in the oliguria and non-oliguria groups. Results: Nine eligible studies with 18 473 patients were included. The meta-analysis revealed that patients with intraoperative oliguria had a considerably greater risk of postoperative AKI (unadjusted OR: 2.03, 95% CI: 1.60-2.58, I² = 63%, P< 0.00001; multivariate- adjusted OR: 2.00, 95% CI: 1.64-2.44, I² = 40%, P< 0.00001). Further subgroup analysis did not find differences between different oliguria criteria or surgical types. Furthermore, the AKI group's pooled intraoperative urine output was less (mean differences: - 0.16, 95% CI: - 0.26 to - 0.07, P< 0.001). Intraoperative oliguria was associated with increased demand for postoperative RRT (risk ratios: 4.71,95% CI: 2.83-7.84, P< 0.001) and in-hospital mortality (risk ratios: 1.83,95% CI: 1.24-2.69, P = 0.002), but not with prolonged length of hospital stay (mean differences: 0.55, 95% CI: - 0.27 to 1.38, P = 0.19). Conclusions: Intraoperative oliguria was significantly associated with a higher incidence of postoperative AKI, as well as increased in-hospital mortality and demand for postoperative RRT, but not with prolonged hospitalization. [ABSTRACT FROM AUTHOR]

Introduction: Preterm babies are a vulnerable population group who are more susceptible to multiple end-organ damage due to an immature immune system and incomplete organogenesis/ organ function. There is scanty data on preterm Acute Kidney Injury (AKI) in India. Aim: To investigate the incidence of acute renal failure and the risk factors predisposing preterm babies to renal failure in an inborn at a tertiary care centre in Southern India. Additionally, we aimed to evaluate the usefulness of a biomarker, Neutrophil Gelatinase Associated Lipocalin (NGAL), as both a marker of renal function and a predictor of AKI in preterm babies. Materials and Methods: A cross-sectional study was conducted in the Neonatal Intensive Care Unit (NICU) at Christian Medical College, Vellore, Tamil Nadu, India, between May 2014 and August 2014. The study included babies born

Background: The role of urine output (UO) in the first 24 h of admission in the clinical management of cardiogenic shock (CS) patients has not been elucidated. Methods: This study retrospectively analyzed intensive care CS patients in the MIMIC-IV database. Binomial logistic regression analysis was conducted to evaluate whether UO was an independent risk factor for in-hospital mortality in CS patients. The performance of UO in predicting mortality was evaluated by the receiver operating characteristic (ROC) curve and compared with the Oxford Acute Severity of Illness Score (OASIS). The clinical net benefit of UO in predicting mortality was determined using the decision curve analysis (DCA). Survival analysis was performed with Kaplan-Meier curves. Results: After adjusting for confounding factors including diuretic use and acute kidney injury (AKI), UO remained an independent risk factor for in-hospital mortality in CS patients. The areas under the ROC curves (AUCs) of UO for predicting in-hospital mortality were 0.712 (UO, ml/day) and 0.701 (UO, ml/kg/h), which were comparable to OASIS (AUC = 0.695). In terms of clinical net benefit, UO was comparable to OASIS, with different degrees of benefit at different threshold probabilities. Survival analysis showed that the risk of in-hospital death in the low-UO (≤857 ml/day) group was 3.0143 times that of the high-UO (>857 ml/day) group. Conclusions: UO in the first 24 h of admission is an independent risk factor for in-hospital mortality in intensive care CS patients and has moderate predictive value in predicting in-hospital mortality.

Purpose: Urine oxygen partial pressure (PuO2) may be useful for assessing acute kidney injury (AKI) risk. The primary purpose of this study was to quantify the ability of a novel urinary oxygen monitoring system to make real-time PuO2 measurements intraoperatively which depends on adequate urine flow. We hypothesized that PuO2 data could be acquired with enough temporal resolution to provide real-time information in both AKI and non-AKI patients. Methods: PuO2 and urine flow were analyzed in 86 cardiac surgery patients. PuO2 data associated with low (< 0.5 ml/kg/hr) or retrograde urine flow were discarded. Patients were excluded if > 70% of their data were discarded during the respective periods, i.e., during cardiopulmonary bypass (CPB), before CPB (pre-CPB), and after CPB (post-CPB). The length of intervals of discarded data were recorded for each patient. The median length of intervals of discarded data were compared between AKI and non-AKI patients and between surgical periods. Results: There were more valid PuO2 data in CPB and post-CPB periods compared to the pre-CPB period (81% and 90% vs. 31% of patients included, respectively; p < 0.001 and p < 0.001). Most intervals of discarded data were < 3 minutes during CPB (96%) and post-CPB (98%). The median length was < 25 s during all periods and there was no significant difference in the group median length of discarded data intervals for AKI and non-AKI patients. Conclusions: PuO2 measurements were acquired with enough temporal resolution to demonstrate real-time PuO2 monitoring during CPB and the post-CPB period. ClinicalTrials.gov Identifier: NCT03335865, First Posted Date: Nov. 8th, 2017. [ABSTRACT FROM AUTHOR]

Introduction: Acute Kidney injury (AKI) is associated with poor outcomes in critically ill hospitalized children. There are very few studies on incidence of AKI based on urine output criteria of KDIGO (Kidney Disease: Improving Global Outcome) and time lag between the fall in urine output and rise in serum creatinine. This study was therefore aimed at determining the same. Methods: A prospective study was conducted in the Department of Paediatrics of a tertiary care hospital. 171 critically ill children between one to 14 years who were admitted in PICU were enrolled. Hourly urine output and eight hourly serum creatinine levels were measured and incidence of AKI was calculated along with lag time between fall in urine output and rise in serum creatinine. Outcome of children with AKI was also studied. Data analysis was done using SPSS software version 25.0 and Microsoft excel 2007. Results: The mean age + SD of children in the study was 5.5 years ± 3.76 with a range of one to 14 years, with 62.6 % of them being boys. The incidence of AKI in the study population was 14.62%. The mean lag time between fall in urine output and rise in serum creatinine was found to be 13.21 hours. AKI had a significant association with mortality, use of nephrotoxic drugs, inotropes and mechanical ventilation. Conclusions: A significant number of critically ill children develop AKI and its occurrence portends a poor outcome. Utilization of the KDIGO reduced urine output criteria as a marker of AKI allows for early detection and intervention. [ABSTRACT FROM AUTHOR]

Background: The aim of this study was to evaluate the effect of caffeine therapy in preventing severe hyperkalemia in preterm infants. Methods: We performed a single‐center, retrospective study of preterm infants of 25–29 weeks' gestation admitted in our neonatal intensive care unit from January 2019–August 2020. We divided the infants into two groups: the control group (January 2019–November 2019) and the early caffeine group (December 2019–August 2020). Results: We identified 33 infants (early caffeine, 15; control, 18). Baseline potassium levels were 5.3 and 4.8 mEq/L, respectively (p = 0.274). Severe hyperkalemia (K > 6.5 mEq/L) was observed in 0 (0%) and 7 (39%) (p = 0.009), in the early caffeine group and control group. The linear mixed‐effect model confirmed the correlation between caffeine therapy and time from birth for the prediction of potassium levels (p < 0.001). While the potassium levels increased from baseline potassium levels at birth by 0.869 mEq/L at 12 h of birth, 0.884 mEq/L at 18 h of birth, and 0.641 mEq/L at 24 h of birth in the control group, the potassium levels were similar to the baseline levels at 12, 18, and 24 h of life in the early caffeine group. Among the clinical features, only early caffeine therapy was negatively associated with the incidence of hyperkalemia within 72 h of life. Conclusion: Early caffeine therapy within a few hours of life effectively prevents the incidence of severe hyperkalemia within the first 72 h of life in preterm infants of 25–29 weeks' gestation. Prophylactic early caffeine therapy can, therefore, be considered in high‐risk, preterm infants. [ABSTRACT FROM AUTHOR]

Introduction/background: Fluid overload is common in critically ill children and is associated with significant morbidity and mortality. Furosemide is the most widely used diuretic to manage excess fluid. In addition to loop diuretics, thiazide diuretics may be used to enhance urine output. Data and information regarding safe and effective dosing of furosemide and chlorothiazide in the critically ill pediatric population are lacking. The primary objective of this study was to compare urine output 24 hours after initiation of furosemide or chlorothiazide in critically ill children. Methods: This was a multi-center retrospective cohort study conducted at 3 academic medical centers. Children between the ages of 1 day and 17 years that received at least one dose of intravenous or oral diuretics from February 2013 to January 2017 were included. Patients with bronchopulmonary dysplasia or on home diuretics were excluded. Only the first dose of diuretic was included in the study. Patients were divided into two groups: furosemide versus chlorothiazide. Urine output 24 hours prior to the diuretic was compared to urine output 24 hours after initiation of the diuretic. Results: There were 133 patients identified who met the inclusion criteria for the study. There were 88 patients that received at least one dose of furosemide and 45 that received at least one dose of chlorothiazide. Most patients were male (49, 55.7%) with a median age of 2.3 years. The median dose for furosemide was 0.7 mg/kg and for chlorothiazide was 2.4 mg/kg. There were no statistically significant differences between baseline urine output for furosemide (2.9 ml/kg/hr) or chlorothiazide (2.8 ml/kg/hr), p=0.6. Although not statistically different, urine output 24 hours after the diuretic dose increased by 0.84 ml/kg/hr for furosemide and 0.73 ml/kg/hr for chlorothiazide, p=0.45. Conclusion: Furosemide and chlorothiazide resulted in similar urine output changes 24 hours after an intravenous dose. [ABSTRACT FROM AUTHOR]

Background: The furosemide stress test (FST) is a safe and easy assessment of renal tubular function. Other factors, such as mean arterial pressure (MAP), which may influence the success rates of the FST, have not been well defined. Objective: To evaluate the relationship between MAP and success rates of the FST in critically ill patients. Methods: Retrospective, single-center, institutional review board (IRB)-approved cohort study. Critically ill adult patients given at least one dose of intravenous (IV) furosemide (≥1-1.5 mg/kg) were included. Primary outcome was whether a MAP ≥ 75 mm Hg would equate to a higher FST success rate. Secondary outcome was the success rates of patient on one or more vasopressors. Results: Of 225 patients, 88 (39.1%) had a successful FST. In patients with a MAP ≥ 75 mm Hg, 60 out of 104 (57.7%) had a successful FST compared to 28 out of 121 (23.1%) of patients who had a MAP < 75 mm Hg (odds ratio [OR], 4.53, 95% CI, 2.55-8.74, P < 0.001). Patients on vasopressors at the time of the furosemide dose had lower rates of success compared to those not on vasoactive agents (30.4% versus 68.2%, p = 0.026). Limitations of this study include its retrospective design and reliance on documented urine output. Conclusion and Relevance: Patients with a MAP ≥ 75 mm Hg were significantly more likely to have a successful FST compared to those with a MAP < 75 mm Hg. This represents the first report of factors that may influence FST success rates. [ABSTRACT FROM AUTHOR]

Abstract Background Sepsis-associated acute kidney injury (S-AKI) is a common and life-threatening complication in hospitalized and critically ill patients. This condition is an independent cause of death. This study was performed to investigate the correlation between the trajectory of urine output within 24 h and S-AKI. Methods Patients with sepsis were studied retrospectively based on the Medical Information Mart for Intensive Care IV. Latent growth mixture modeling was used to classify the trajectory of urine output changes within 24 h of sepsis diagnosis. The outcome of this study is AKI that occurs 24 h after sepsis. Cox proportional hazard model, Fine–Gray subdistribution proportional hazard model, and doubly robust estimation method were used to explore the risk of AKI in patients with different trajectory classes. Results A total of 9869 sepsis patients were included in this study, and their 24-h urine output trajectories were divided into five classes. The Cox proportional hazard model showed that compared with class 1, the HR (95% CI) values for classes 3, 4, and 5 were 1.460 (1.137–1.875), 1.532 (1.197–1.961), and 2.232 (1.795–2.774), respectively. Competing risk model and doubly robust estimation methods reached similar results. Conclusions The trajectory of urine output within 24 h of sepsis patients has a certain impact on the occurrence of AKI. Therefore, in the early treatment of sepsis, close attention should be paid to changes in the patient's urine output to prevent the occurrence of S-AKI.

Background: Nephrocheck® was approved for acute kidney injury (AKI) risk assessment in critically illness. However, new studies suggest that urinary concentration affects Nephrocheck® and previous studies did not provide data on urinary output (UO) at the time of measurement. Methods: We performed a prospective cohort study of the Nephrocheck® in intensive care unit patients fulfilling standard inclusion criteria. The primary outcome was Stage 2 or 3 AKI defined by both UO and creatinine Kidney Disease Improving Global Outcomes (KDIGO) criteria in the subsequent 12 h. The secondary outcome was the relationship of UO with Nephrocheck® measurement. Results: Among 98 patients, the primary outcome occurred in 53 (54.1%) overall, but in 23 (23.5%) by creatinine criteria alone. The median (interquartile range) Nephrocheck® in patients with subsequent Stage 2 or 3 AKI was greater than in Stage 1 or no‐AKI patients (0.97 [0.48–1.99] vs. 0.46 [0.22–1.17]; p =.005). However, its area under the receiver characteristic curve was 0.66 (95% confidence interval [CI], 0.56–0.77). Moreover, Nephrocheck® was significantly and inversely correlated with UO (ρ = −.46, p <.001) at the time of measurement and, on a multivariable logistic regression, Nephrocheck® was not associated with subsequent Stage 2 or 3 AKI (OR 1.06 [95% CI, 0.74–1.53], p =.73). In contrast, the UO had an OR of 0.98 for each ml/h increase (95% CI, 0.97–1.00, p =.007). Conclusion: Nephrocheck®'s predictive performance was limited and its value was inversely correlated with UO. Nephrocheck® had no independent relationship with outcome once UO at measurement was considered. [ABSTRACT FROM AUTHOR]

The Kidney Disease Improving Global Outcomes (KDIGO) guidelines are currently used in acute kidney injury (AKI) diagnosis and include both serum creatinine (SCR) and urine output (UO) criteria. Currently, many AKI-related studies have inconsistently defined AKI, which possibly affects the comparison of their results. Therefore, we hypothesized that the different criteria in the KDIGO guidelines vary in measuring the incidence of AKI and its association with clinical outcomes. We retrospectively analyzed that data of patients admitted to the intensive care unit after non-cardiac surgery in 2019. Three different criteria used to define AKI were included: UOmean, mean UO < 0.5 mL/kg/h over time; UOcont, hourly UO < 0.5 mL/kg/h over time; or SCR, KDIGO guidelines SCR criteria. A total of 777 patients were included, and the incidence of UOmean-AKI was 33.1%, the incidence of UOcont-AKI was 7.9%, and the incidence of SCR-AKI was 2.0%. There were differences in the length of ICU stay and hospital stay between AKI and non-AKI patients under different criteria. We found differences in the incidence and clinical outcomes of AKI after non-cardiac surgery when using different KDIGO criteria. [ABSTRACT FROM AUTHOR]

Objective: Evaluating the association of water intake and hydration status with nephrolithiasis risk at the population level.Design: It is a cross-sectional study in which daily total plain water intake and total fluid intake were estimated together with blood osmolality, urine creatinine, urine osmolality, urine flow rate (UFR), free water clearance (FWC) and urine/blood osmolality ratio (Uosm:Bosm). The associations of fluid intake and hydration markers with nephrolithiasis were evaluated using multivariable logistic regression.Setting: General US population.Participants: A total of 8195 adults aged 20 years or older from the National Health and Nutritional Examination Survey 2009-2012 cycles.Results: The population medians (interquartile ranges, IQR) for daily total plain water intake and total fluid intake were 807 (336-1481) and 2761 (2107-3577) ml/d, respectively. The adjusted OR (95 % CI) of nephrolithiasis for each IQR increase in total plain water intake and total fluid intake were 0·92 (95 % CI 0·79, 1·06) and 0·84 (95 % CI 0·72, 0·97), respectively. The corresponding OR of nephrolithiasis for UFR, blood osmolality, Uosm:Bosm and urine creatinine were 0·87 (95 % CI 0·76, 0·99), 1·18 (95 % CI 1·06, 1·32), 1·38 (95 % CI 1·17, 1·63) and 1·27 (95 % CI 1·11, 1·45), respectively. A linear protective relationship of fluid intake, UFR and FWC with nephrolithiasis risk was observed. Similarly, positive dose-response associations of nephrolithiasis risk with markers of insufficient hydration were identified. Encouraging a daily water intake of >2500 ml/d and maintaining a urine output of 2 l/d was associated with a lower prevalence of nephrolithiasis.Conclusion: This study verified the beneficial role of general water intake recommendations in nephrolithiasis prevention in the general US population. [ABSTRACT FROM AUTHOR]