Urine Output Criteria Research Articles

Urine Output and Acute Kidney Injury in Neonates/Younger Children: A Prospective Study of Cardiac Surgery Patients with Indwelling Urinary Catheters.

Pediatric acute kidney injury (AKI) is associated with significant morbidity and mortality, yet a precise definition, especially concerning urine output (UO) thresholds, remains unproven. We evaluate UO thresholds for AKI in neonates and children aged 1-24 months with indwelling urinary catheters undergoing cardiac surgery. A six-year prospective cohort study (2018-2023) after cardiac surgery was conducted at a reference center in Brazil. All patients had indwelling urinary catheters up to 48 hours after surgery and at least two serum creatinine (sCr) measurements, including one before surgery. The main objective of this study was to determine the optimal UO thresholds for AKI definition and staging in neonates and younger children compared with the currently used criteria-neonatal and adult Kidney Disease Improving Global Outcomes (KDIGO) definitions. The outcome was a composite of severe AKI (stage 3 AKI diagnosed by the sCr criterion only), kidney replacement therapy, or hospital mortality. The study included 1,024 patients: 253 in the neonatal group and 772 in the younger children group. In both groups, the lowest UO at 24 hours as a continuous variable had good discriminatory capacity for the composite outcome (AUC-ROC 0.75 [95% CI 0.70-0.81] and 0.74 [95% CI 0.68-0.79]). In neonates, the best thresholds were 3.0, 2.0 and 1.0 mL/kg/hour, and in younger children, the thresholds were 1.8, 1.0 and 0.5 mL/kg/hour. These values were used for modified AKI staging for each age group. In neonates, this modified criterion was associated with the best discriminatory capacity (AUC-ROC 0.74 [0.67-0.80] vs. 0.68 [0.61-0.75], P<0.05) and net reclassification improvement (NRI) in comparison with the neonatal KDIGO criteria. In younger children, the modified criteria had good discriminatory capacity but were comparable to the adult KDIGO criteria, and the NRI was near zero. Using indwelling catheters for UO measurements, our study reinforced that the current KDIGO criteria may require adjustments to better serve the neonate population. Additionally, using the UO criteria, we validated the adult KDIGO criteria in children aged 1-24 months.

To Evaluate the Role of Comorbidities in the Development of Acute Kidney Injury in Intensive Care Patients at a Tertiary Care Hospital in Bangladesh

Background: Indeed, AKI is a common complication in ICU patients, and it is associated with an increase in morbidity and mortality as well as healthcare costs. Recognizing AKI risk factors in LMIC settings is important for intervention approaches. Objectives: The objectives of this study are as follows: To determine the incidence of AKI based on RIFLE criteria among the critically ill patients in a tertiary care hospital in Bangladesh and to analyze the impact of the presence of comorbidities on the development of AKI in these patients. Methods: This prospective observational study was carried out at the ICU of Community Based Medical College in Bangladesh from January to December 2023. The target subjects were adult patients who were admitted to the ICU for a period of 24 to 48 hours. Patients with AKI were categorized using RIFLE criteria based on serum creatinine and urine output. For the univariate and multivariate logistic regression, demographic data, comorbidities, and clinical characteristics were collected. Results: In the present study of 22 patients with a mean age of 42.16 years and 63.6% of male patients, 86.4 percent of the patients had AKI according to both serum creatinine and urine output criteria. Sepsis/septic shock ([OR] 2. 2, [CI] 0. 8–5. 8) and cardiac etiology ([OR] 2. 7, [CI] 1. 0–7.1) were significant predictors of AKI. The study revealed that respiratory disease [OR. = 3.56, 95% confidence interval (CI): 0.33–38.78] and hematologic malignancy [OR. = 4.20, 95% CI: 0.40–43.82] were the comorbid conditions most closely associated with AKI. Conclusions: This research shows a very high prevalence rate of AKI among the clients in critical conditions in Bangladesh. Sepsis, cardiac dysfunction, respiratory disease, and hematologic malignancies emerged as significant factors. The results are therefore informative for programs aimed at improving AKI awareness, early detection activities, and prevention efforts in low-resource settings.

Perioperative risk factors for acute kidney injury in major abdominal surgeries: a retrospective observatioal study

Aims: Acute kidney injury (AKI), particularly as a postoperative complication related to surgery, has been independently associated with morbidity and mortality. AKI also develops at a significant rate after major abdominal surgery. In this study, it was aimed to identify the risk factors contributing to the development of AKI following major abdominal surgery. Methods: The study was retrospectively planned. Patients who underwent major abdominal surgery were included in the study. Patients’ demographic data, preoperative laboratory data, intraoperative data, and postoperative data were recorded from patient files. The diagnosis and severity of postoperative acute kidney injury (PO-AKI) were assessed using serum creatinine and/or urine output criteria in accordance with the Kidney Disease: Improving Global Outcomes (KDIGO) guidelines. The patients were divided into two groups: AKI and non-AKI. Results: A total of 64 patients with complete data were included in the study. Among these patients, 6 developed AKI (9.3%). The mean age in the AKI group was found to be statistically significantly higher (p: 0.043). The Frailty index was significantly higher in the AKI group (p: 0.020). Additionally, it was observed that the use of aspirin and angiotensin-converting enzyme inhibitor (ACEI) / angiotensin receptor blocker (ARB) was statistically significantly higher in the AKI group (p: 0.022, p: 0.044, respectively). When patients were evaluated in terms of intraoperative parameters, the amount of colloid used, the amount of ES used, and vasopressor usage were found to be statistically significantly higher in the AKI group (p

CCL14 Predicts Oliguria and Dialysis Requirement in Patients with Moderate to Severe Acute Kidney Injury

Introduction: AKI is a frequent complication of critical illness and portends poor outcome. CCL14 is a validated predictor of persistent severe AKI in critically ill patients. We examined the association of CCL14 with urine output within 48 h. Methods: In pooled data from 2 studies of critically ill patients with KDIGO stage 2–3 AKI, CCL14 was measured by NEPHROCLEAR™ CCL14 Test on the Astute 140® Meter (low, intermediate, and high categories [1.3 and 13 ng/mL]). Average hourly urine output over 48 h, stage 3 AKI per urine output criterion on day 2, and composite of dialysis or death within 7 days were examined using multivariable mixed and logistic regression models. Results: Of the 497 subjects with median age of 65 (56–74) years, 49% (242/497) were on diuretics. CCL14 concentration was low in 219 (44%), intermediate in 217 (44%), and high in 61 (12%) patients. In mixed regression analysis, hourly urine output over time was different within each CCL14 risk category based on diuretic use due to significant three-way interaction (p < 0.001). In logistic regression analysis, CCL14 risk category was independently associated with low urine output on day 2 per KDIGO stage 3 (adjusted for diuretic use and baseline clinical variables), and composite of dialysis or death within 7 days (adjusted for urine output within 48 h of CCL14 measurement). Conclusions: CCL14 measured in patients with moderate to severe AKI is associated with urine output trajectory within 48 h, oliguria on day 2, and dialysis within 7 days.

Quantifying the Impact of Alternative Definitions of Sepsis-Associated Acute Kidney Injury on its Incidence and Outcomes: A Systematic Review and Meta-Analysis.

To derive a pooled estimate of the incidence and outcomes of sepsis-associated acute kidney injury (SA-AKI) in ICU patients and to explore the impact of differing definitions of SA-AKI on these estimates. Medline, Medline Epub, EMBASE, and Cochrane CENTRAL between 1990 and 2023. Randomized clinical trials and prospective cohort studies of adults admitted to the ICU with either sepsis and/or SA-AKI. Data were extracted in duplicate. Risk of bias was assessed using adapted standard tools. Data were pooled using a random-effects model. Heterogeneity was assessed by using a single covariate logistic regression model. The primary outcome was the proportion of participants in ICU with sepsis who developed AKI. A total of 189 studies met inclusion criteria. One hundred fifty-four reported an incidence of SA-AKI, including 150,978 participants. The pooled proportion of patients who developed SA-AKI across all definitions was 0.40 (95% CI, 0.37-0.42) and 0.52 (95% CI, 0.48-0.56) when only the Risk Injury Failure Loss End-Stage, Acute Kidney Injury Network, and Improving Global Outcomes definitions were used to define SA-AKI. There was significant variation in the incidence of SA-AKI depending on the definition of AKI used and whether AKI defined by urine output criteria was included; the incidence was lowest when receipt of renal replacement therapy was used to define AKI (0.26; 95% CI, 0.24-0.28), and highest when the Acute Kidney Injury Network score was used (0.57; 95% CI, 0.45-0.69; p < 0.01). Sixty-seven studies including 29,455 participants reported at least one SA-AKI outcome. At final follow-up, the proportion of patients with SA-AKI who had died was 0.48 (95% CI, 0.43-0.53), and the proportion of surviving patients who remained on dialysis was 0.10 (95% CI, 0.04-0.17). SA-AKI is common in ICU patients with sepsis and carries a high risk of death and persisting kidney impairment. The incidence and outcomes of SA-AKI vary significantly depending on the definition of AKI used.

Association of continuous kidney replacement therapy timing and mortality in critically ill children.

Acute kidney injury (AKI) is a common complication of critical illness and associated with high morbidity and mortality. Optimal timing of continuous kidney replacement therapy (CKRT) in children is unknown. We aimed to measure the association between timing of initiation and mortality. This is a single-center retrospective cohort study of pediatric patients receiving CKRT from 2013 to 2019. The primary exposure, time to CKRT initiation, was measured from onset of stage 3 AKI during hospitalization (defined using Kidney Disease: Improving Global Outcomes creatinine and urine output criteria) and analyzed as both a continuous and categorical variable. The primary outcome was ICU mortality. Ninety-nine patients met criteria for analysis. Overall mortality was 39% (39/99). Median time from stage 3 AKI onset to CKRT initiation was 1.5days in survivors and 5.5days in nonsurvivors (p < 0.001). In multivariable analysis, increased time to CKRT initiation was independently associated with mortality [OR 1.02 per hour (95% CI 1.01-1.04), p < 0.001]. Longer time to CKRT initiation was associated with higher odds of mortality in ascending time intervals. Patients started on CKRT > 2days compared to < 2days after stage 3 AKI onset had higher mortality (65% vs. 5%, p < 0.001), longer median ICU length of stay (25 vs. 12 d, p < 0.001), longer median CKRT duration (11 vs. 5 d, p < 0.001), and fewer AKI-free days (0 vs. 14 d, p < 0.001). Longer time to initiation of CKRT after development of severe AKI is independently associated with mortality. Consideration of early CKRT in this high-risk population may be a strategy to reduce mortality and improve recovery of kidney function. However, there remains significant heterogeneity in the definition of early versus late initiation and the optimal timing of CKRT remains unknown.

Acute Kidney Injury in Neonates Admitted to a Low-Resource Neonatal Intensive Care Unit in Lusaka, Zambia.

Neonatal acute kidney injury (nAKI) has been reported to be common among neonates admitted to the Neonatal Intensive Care Unit (NICU) and is associated with increased mortality and prolonged duration of hospital stay. However, data on this entity from sub-Saharan Africa are scanty. This study aimed to assess the burden, risk factors, and short-term outcomes of nAKI in neonates admitted to a low-resource NICU in Zambia. The design of the study is a prospective cohort study. The setting of this study was the NICU at the Women and Newborn Hospital of the University Teaching Hospitals (WNBH-UTHs). In total, 322 neonates who were admitted to the NICU between November 2021 and December 2022. A serum creatinine was determined on all patients at admission (within 24 hours), at 72 hours and day 7. The modified neonatal Kidney Disease: Improving Global Outcome (KDIGO) Criteria were used to define nAKI. Data were extracted using a predesigned form and analyzed using SPSS. A P-value less than .05 was considered statistically significant. The prevalence of nAKI was 13.7% (44/322). On multivariable regression analysis, antepartum hemorrhage (adjusted odds ratio [AOR] 5.58; 95% confidence interval [CI]: [1.62-19.13], P = .007), vomiting in the neonate (AOR 5.76; 95% CI: [1.10-30.32], P = .04), history of use of unit second-line antibiotics, meropenem (AOR 4.37; 95% CI: [1.97-9.69], P < .001), and ciprofloxacin (AOR 4.53; 95% CI: [1.22-16.84], P = .02) were associated with increased risk of nAKI. Acute kidney injury (AKI) was significantly associated with longer length of hospital stay and higher mortality (P < .05). The study did not use the urine output criteria to define nAKI and this may have led to an underestimation of nAKI prevalence. Additionally, kidney, ureter, and bladder ultrasound was not performed on any of the study participants. AKI is common in neonates admitted to the NICU at WNBH-UTHs, and it is associated with a higher risk of mortality and prolonged length of hospital stay. Further studies among the various NICU sub-populations are needed to better characterize risks and outcomes.

Adjusting Acute Kidney Injury Kidney Disease: Improving Global Outcomes Urine Output Criterion for Predicted Body Weight Improves Prediction of Hospital Mortality.

Based on the Kidney Disease: Improving Global Outcomes (KDIGO) definitions, urine output, serum creatinine, and need for kidney replacement therapy are used for staging acute kidney injury (AKI). Currently, AKI staging correlates strongly with mortality and can be used as a predictive tool. However, factors associated with the development of AKI may affect its predictive ability. We tested whether adjustment for predicted (versus actual) body weight improved the ability of AKI staging to predict hospital mortality. A total of 3279 patients who had undergone cardiac surgery in a university hospital were retrospectively analyzed. AKI was staged according to KDIGO criteria (standard staging) and after adjustment for hourly urine output adjusted by predicted body weight for each patient and each day of their hospital stay. The incidence of AKI (all stages) was 43% (predicted body weight adjusted) and 50% (standard staging), respectively (P < .001). In sensitivity-specificity analyses for predicting hospital mortality, the area under the curve was significantly higher after adjustment for predicted body weight than with standard staging (P = .002). Compared to standard staging, adjustment of urine output for predicted body weight increases the specificity and improves prediction of hospital mortality in patients undergoing cardiac surgery.

Incremental versus conventional haemodialysis in end-stage kidney disease: a systematic review and meta-analysis.

Appropriate dialysis prescription in the transitional setting from chronic kidney disease to end-stage kidney disease is still challenging. Conventional thrice-weekly haemodialysis (HD) might be associated with rapid loss of residual kidney function (RKF) and high mortality. The benefits and risks of incremental HD compared with conventional HD were explored in this systematic review and meta-analysis. We searched MEDLINE, Scopus and Cochrane Central Register of Controlled Trials up to April 2023 for studies that compared the impacts of incremental (once- or twice-weekly HD) and conventional thrice-weekly HD on cardiovascular events, RKF, vascular access complications, quality of life, hospitalization and mortality. A total of 36 articles (138939 participants) were included in this meta-analysis. The mortality rate and cardiovascular events were similar between incremental and conventional HD {odds ratio [OR] 0.87 [95% confidence interval (CI)] 0.72-1.04 and OR 0.67 [95% CI 0.43-1.05], respectively}. However, hospitalization and loss of RKF were significantly lower in patients treated with incremental HD [OR 0.44 (95% CI 0.27-0.72) and OR 0.31 (95% CI 0.25-0.39), respectively]. In a sensitivity analysis that included studies restricted to those with RKF or urine output criteria, incremental HD had significantly lower cardiovascular events [OR 0.22 (95% CI 0.08-0.63)] and mortality [OR 0.54 (95% CI 0.37-0.79)]. Vascular access complications, hyperkalaemia and volume overload were not statistically different between groups. Incremental HD has been shown to be safe and may provide superior benefits in clinical outcomes, particularly in appropriately selected patients. Large-scale randomized controlled trials are required to confirm these potential advantages.

Acute and long-term renal effects after iodine contrast media–enhanced computerised tomography in the critically ill—a retrospective bi-centre cohort study

ObjectivesTo determine if current clinical use of iodine contrast media (ICM) for computerised tomography (CT) increases the risk of acute kidney injury (AKI) and long-term decline in renal function in patients treated in intensive care.MethodsA retrospective bi-centre cohort study was performed with critically ill subjects undergoing either ICM-enhanced or unenhanced CT. AKI was defined and staged based on the Kidney Disease Improve Global Outcome AKI criteria, using both creatinine and urine output criteria. Follow-up plasma creatinine was recorded three to six months after CT to assess any long-term effects of ICM on renal function.ResultsIn total, 611 patients were included in the final analysis, median age was 65.0 years (48.0–73.0, quartile 1–quartile 3 (IQR)) and 62.5% were male. Renal replacement therapy was used post-CT in 12.9% and 180-day mortality was 31.2%. Plasma creatinine level on day of CT was 100.0 µmol/L (66.0–166.5, IQR) for non-ICM group and 77.0 µmol/L (59.0–109.0, IQR) for the ICM group. The adjusted odds ratio for developing AKI if the patient received ICM was 1.03 (95% confidence interval 0.64–1.66, p = 0.90). No significant association between ICM and increase in plasma creatinine at long-term follow-up was found, with an adjusted effect size of 2.92 (95% confidence interval − 6.52–12.36, p = 0.543).ConclusionsThe results of this study do not indicate an increased risk of AKI or long-term decline in renal function when ICM is used for enhanced CT in patients treated at intensive care units.Clinical relevance statementPatients treated in intensive care units had no increased risk of acute kidney injury or persistent decline in renal function after contrast-enhanced CT. This information underlines the need for a proper risk-reward assessment before denying patients a contrast-enhanced CT.Key Points• Iodine contrast media is considered a risk factor for the development of acute kidney injury.• Patients receiving iodine contrast media did not have an increased incidence of acute kidney injury or persistent decline in renal function.• A more clearly defined risk of iodine contrast media helps guide clinical decisions whether to perform contrast-enhanced CTs or not.

Incidence of Acute Kidney Injury in 1 - 14 years old Critically ill Children in a Tertiary care Center

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.&#x0D; 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.&#x0D; 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.&#x0D; 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

SP4.4 A Prospective Diagnostic study investigating Urinary Biomarkers of AKI in Major Abdominal Surgery (The AKI-BioMAS Study)

Abstract Aims To characterize biomarker performance in predicting Acute Kidney Injury (AKI) in Major Abdominal Surgery using both the Kidney Disease: Improving Global Outcomes (KDIGO) serum creatinine (AKISCr) and urine output (AKIUO) criteria. Post-operative AKI is associated with increased morbidity and mortality. Research assessing AKI biomarkers has focussed on cardiac, vascular and transplant surgery cohorts. Few studies have addressed Major Abdominal Surgery. Methods This prospective observational diagnostic study was conducted on 488 major abdominal surgery patients. Urine was collected four hours post-surgery. Biomarkers measured were NGAL, KIM-1, DKK-3 and IGFBP-7*TIMP-2. Diagnostic performance was assessed utilizing Receiver Operating Characteristic (ROC) curve analysis. Results 242 participants developed AKIUO (49.5%) and 43 AKISCr (8.8%). The area under the receiver operating characteristic curve (AUC) values for stage 1 AKISCr using NGAL was 0.741 (95%CI 0.699-0.770, p&amp;lt;0.001) and 0.871 (95%CI 0.838-.899, p&amp;lt;0.001) for stage 2. AUC values for IGFBP-7*TIMP-2 for stage 1 were 0.655 (95% CI 0.611-0.697, p0.003) and stage 2 0.803 (95%CI 0.764-0.837 p0.002). The AUC for KIM-1 was statistically significant for stage 1 (0.68, 95%CI 0.637-0.722) but not for stage 2. No AUC values for DKK-3 were statistically significant. Biomarkers performed poorly for stage 1 and 2 AKIUO with AUC values of &amp;lt;0.65. Conclusions AKI rates following Major Abdominal Surgery are dependent on criteria used. Given the numerous confounders affecting urine output post-operatively it may be that current AKIUO criteria in patients undergoing Major Abdominal Surgery may be inappropriate. This is reflected in poor diagnostic performance of biomarkers in this context. Biomarkers performed better when assessing AKISCr, with NGAL returning the highest AUC values.

A novel acute kidney injury scoring system for renal and clinical outcomes in pediatric heart transplant patients.

The development of acute kidney injury (AKI) has been associated with worse outcomes in children after heart transplantation. Our study compares the application of a cumulative six-point Kidney Diseases Improving Global Outcomes (KDIGO) AKI scoring system, utilizing both creatinine and urine output criteria that we term as the AKI-6 criteria, to traditional AKI staging as a predictor for clinical and renal outcomes in the pediatric heart transplant recipients. We conducted a retrospective single-center chart review on 155 pediatric patients who underwent heart transplantation from May 2014 to December 2021. The primary independent variable was the presence of severe AKI. Severe AKI by KDIGO was defined as Stage ≥2, whereas severe AKI by AKI-6 was defined as cumulative scores ≥4 or Stage 3 AKI based on either KDIGO criterion alone. Primary outcomes included actuarial survival and renal dysfunction by 1-year post-transplant, defined as an estimated glomerular filtration rate <60 mL/min/1.73 m2 . In total, 140 (90%) patients developed AKI; 98 (63%) patients developed severe AKI by KDIGO, and 60 (39%) by AKI-6. Severe AKI by AKI-6 was associated with worse actuarial survival following heart transplantation compared with KDIGO (p = 0.01). Of the 143 patients with 1-year creatinine data, 6 (11%) patients out of 54 with severe AKI by AKI-6 had evidence of renal dysfunction (p = 0.01), compared with 6 (7%) patients out of 88 by KDIGO (p = 0.3). AKI-6 scoring provides greater prognostic utility for actuarial survival and renal dysfunction by 1-year post-heart transplantation in pediatric patients than traditional KDIGO staging.

Neurodevelopment After Neonatal Acute Kidney Injury in Very Preterm-Birth Children

This study aimed to assess head circumference (HC) growth and neurodevelopmental outcomes in very preterm-birth children after neonatal acute kidney injury (AKI). This longitudinal follow-up cohort included 732 very preterm neonates of gestational age<31 weeks admitted to a tertiary center between 2008 and 2020. AKI was categorized as nonoliguric and oliguric AKI based on the urine output criteria during admission. We compared the differences in death, z scores of HC (zHC) at term-equivalent age (TEA) and at corrected ages of 6, 12, and 24 months, and the neurodevelopmental outcomes at corrected age of 24 months after neonatal nonoliguric and oliguric AKI. Among the 154 neonates who developed AKI, 72 had oliguric AKI and 82 had nonoliguric AKI. At TEA, oliguric AKI, but not nonoliguric AKI, was independently associated with lower zHC than non-AKI (mean differences,-0.49; 95% confidence interval [CI],-0.92 to-0.06). Although the 3 groups were comparable in zHC at corrected ages of 6, 12, and 24 months, the oliguric AKI group, but not the nonoliguric AKI group, had a higher rate of microcephaly by corrected age of 24 months. In addition, the oliguric AKI group, but not the nonoliguric AKI group, was more likely to die (61% vs. 9%) and have neurodevelopmental impairment (41% vs. 14%) compare with the non-AKI group. After adjustment, oliguric (adjusted odds ratio [aOR], 8.97; 95% CI, 2.19-36.76), but not nonoliguric, AKI was associated with neurodevelopmental impairment. Neonatal oliguric AKI is associated with neurodevelopmental impairment in very preterm-birth children. Long-term head-size and neurodevelopmental follow-up after neonatal AKI is warranted.

Prediction differences and implications of acute kidney injury with and without urine output criteria in adult critically ill patients.

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. 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. 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)]. 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.

Survival outcomes in older patients with different stages of acute kidney injury defined by the addition of urine output criteria.

Survival outcomes in older patients with different stages of acute kidney injury defined by the addition of urine output criteria.

Diagnosing acute kidney injury ahead of time in critically ill septic patients using kinetic estimated glomerular filtration rate

IntroductionAccurate and actionable diagnosis of Acute Kidney Injury (AKI) ahead of time is important to prevent or mitigate renal insufficiency. The purpose of this study was to evaluate the performance of Kinetic estimated Glomerular Filtration Rate (KeGFR) in timely predicting AKI in critically ill septic patients. MethodsWe conducted a retrospective analysis on septic ICU patients who developed AKI in AmsterdamUMCdb, the first freely available European ICU database. The reference standard for AKI was the Kidney Disease: Improving Global Outcomes (KDIGO) classification based on serum creatinine and urine output (UO). Prediction of AKI was based on stages defined by KeGFR and UO. Classifications were compared by length of ICU stay (LOS), need for renal replacement therapy and 28-day mortality. Predictive performance and time between prediction and diagnosis were calculated. ResultsOf 2492 patients in the cohort, 1560 (62.0%) were diagnosed with AKI by KDIGO and 1706 (68.5%) by KeGFR criteria. Disease stages had agreement of kappa = 0.77, with KeGFR sensitivity 93.2%, specificity 73.0% and accuracy 85.7%. Median time to recognition of AKI Stage 1 was 13.2 h faster for KeGFR, and 7.5 h and 5.0 h for Stages 2 and 3. Outcomes revealed a slight difference in LOS and 28-day mortality for Stage 1. ConclusionsPredictive performance of KeGFR combined with UO criteria for diagnosing AKI is excellent. Compared to KDIGO, deterioration of renal function was identified earlier, most prominently for lower stages of AKI. This may shift the actionable window for preventing and mitigating renal insufficiency.

Association of early postoperative serum magnesium with acute kidney injury after cardiac surgery

Introduction Dysmagnesemia has been demonstrated to be involved in the pathophysiology of kidney diseases and is common in cardiac surgical patients. It remains unknown whether changes of serum magnesium after cardiac surgery affect AKI. We aimed to investigate the association of early postoperative magnesium with cardiac surgery-associated AKI in adults. Methods We conducted a multicenter retrospective cohort study involving patients who underwent cardiac surgery in the eICU Collaborative Research Database between 2014 and 2015. AKI within 7 days after surgery was defined using both serum creatinine and urine output criteria of Kidney Disease Improving Global Outcomes definition. Postoperative AKI was analyzed using multivariable logistic regression with early postoperative serum magnesium measured within the first 24 h after surgery as a continuous variable and categorically by quartiles. Results Postoperative AKI was identified in 3498 of 6124 (57.1%) patients receiving cardiac surgery. The median (25th–75th percentiles) early postoperative serum magnesium level of the study population was 2.3 (2.0–2.7) mg/dL. Higher serum magnesium level was associated with a higher risk of developing postoperative AKI (adjusted odds ratio (OR), 1.46 per 1 mg/dL increase; 95% confidence interval (CI), 1.31–1.62; p<.001). The multivariable-adjusted ORs (95% CIs) of postoperative AKI across increasing quartiles of serum magnesium were 1.00 (referent), 1.11 (0.95–1.29), 1.30 (1.12–1.52), and 1.72 (1.47–2.02) (p for trend <.001). Conclusions These data demonstrate a significantly higher incidence of AKI in patients with higher early postoperative serum magnesium who underwent cardiac surgery.

Mortality and Cumulative Kidney Score are Associated with Transient and Persistent Acute Kidney Injury in Septic Patients: A Retrospective Study Based on MIMIC-IV.

Acute kidney injury (AKI) is frequently caused by sepsis. Recently, the Acute Disease Quality Initiative (ADQI) workgroup further classified AKI as transient or persistent. Oliguria and increased serum creatinine represent two different kinds of renal impairment. The aim of the study was to assess mortality and cumulative AKI score associated with transient and persistent AKI in septic patients. Septic patients were stratified according to the presence and AKI development (considered persistent when remaining >48 h) were included. An adjusted logistic regression model was used to determine hospital mortality. In addition, we calculated an AKI score by combining both Kidney Disease: Improving Global Outcomes (KDIGO) criteria of urine output and creatinine AKI stages. The relationship between the cumulative AKI score and persistent AKI was further examined using the logistic regression model and receiver operating characteristic (ROC) curve analysis. 12928 septic patients were enrolled in the study. AKI occurred in 73.7% of septic patients, in 39.5% was transient and in 60.5% was persistent. Patients with persistent AKI had higher severity scores and more severe renal dysfunction upon admission. Persistent AKI, but not transient AKI, was associated with increased intensive care units (ICUs) and hospital mortality. Then we found that the cumulative AKI score was associated with an increased risk of persistent AKI. This association was consistent across three original KDIGO severity stages and subgroup analyses. It was found that persistent AKI was independently associated with mortality in septic patients. Furthermore, serum creatinine and urine output criteria had cumulative effects on KDIGO AKI staging and provided more information about the relationship between AKI and outcomes.

The effect of early diuretics administration on acute kidney injury progression after cardiac surgery: a post-hoc analysis of a multicenter retrospective cohort study (BROTHER study)

Positive fluid balance is associated with acute kidney injury (AKI) following cardiac surgery in a dose-dependent manner. Although diuresis is a common intervention for fluid overload, the optimal timing of diuretic administration for preventing AKI after cardiac surgery remains unclear. We aimed to investigate whether early administration of diuretics after cardiac surgery is associated with subsequent AKI progression. This was a post-hoc analysis of a multicenter retrospective cohort study that included adult patients admitted to 14 intensive care units (ICUs) after elective cardiac surgery between January and December 2018. The exposure variable was the administration of intravenous diuretics during the initial 24 hours after ICU admission. The primary outcome was AKI progression, defined as one or more AKI stages using Kidney Disease: Improving Global Outcomes creatinine and urine output criteria between 24 and 72 hours compared with the worst stage during the first 24 hours. We used multivariable logistic regression analyses to assess the association between early administration of diuretics and AKI progression. Among the 718 patients analyzed, 335 (47%) received intravenous diuretics within the first 24 hours, and AKI progression occurred in 115 patients (16%). In the multivariable analyses, early diuresis was not associated with AKI progression (odds ratio, 1.12; 95% confidence interval, 0.74–1.69), confirmed by sensitivity analyses. Early administration of intravenous diuretics was not associated with a lower risk of AKI progression after cardiac surgery.