Serum Creatinine Criteria Research Articles

Predictors of Acute Kidney Injury Resolution and Associated Clinical Outcomes Among Hospitalized Patients with Cirrhosis.

Background: Acute kidney injury (AKI) is one of the common complications of liver cirrhosis. It occurs in nearly 20% of patients with cirrhosis who are hospitalized. Prior literature demonstrated that the AKI occurrence in patients with cirrhosis is independently associated with higher mortality. However, there are data assessing predictors and outcomes of AKI resolution in hospitalized patients with cirrhosis. Therefore, the aim of the current study was to identify clinical predictors of AKI resolution among inpatients with cirrhosis that are easily obtained and to evaluate the clinical outcomes of those patients. Methods: The current study is a retrospective cohort of patients with cirrhosis who were hospitalized and had AKI between 2012 and 2020 at a tertiary referral center. Patients included in this study were identified using the International Classification of Diseases 9 codes and then they were manually verified by two independent chart reviewers. AKI was classified according to the AKI Network (AKIN) serum creatinine (Cr) criteria, with AKIN resolution defined as AKIN stage 1 or lower at the time of discharge, while unresolved AKIN was defined as AKIN stage 2 or 3 at the time of discharge. For univariate analysis, Fisher's exact and the two-sample T-test were utilized. For multivariable analysis, stepwise logistic regression was performed to evaluate variables associated with AKIN resolution. Survival curves were estimated and compared using the Kaplan-Meier method and Log-Rank Test. A p-value cutoff of 0.05 was used for statistical significance. Results: Between 2012 and 2020, there were 140 patients who were included (59% males). The majority of patients had viral hepatitis (54%) as the cirrhosis etiology with 80% of them having hepatitis C virus. Most patients had fluid-responsive AKI (49%), and stage 1 AKIN (69%). In terms of outcomes, the majority of patients (117 patients; 84%) had AKIN resolution at the time of discharge. In the multivariable analysis, after adjusting for clinical meaningful variables, our study shows that higher albumin value at the time of admission (adjusted Odds Ratio "aOR" = 3.28; p = 0.01) and non-metabolic dysfunction-associated steatotic liver disease (non-MASLD) cirrhosis (aOR = 9.43; p < 0.01) were variables associated with higher odds of AKIN resolution at the time of discharge. Conversely, we show that a higher Cr value at the time of admission was associated with lower odds of AKIN resolution at the time of discharge (aOR = 0.31; p < 0.01). When evaluating mortality, patients with unresolved AKIN at the time of discharge had higher rates of in-hospital mortality (p < 0.01) compared to those with resolved AKIN. Survival curve analyses using the Kaplan-Meier method indicated that patients with resolved AKIN experienced higher 90-day survival rates (p < 0.01). Additionally, those with resolved AKIN demonstrated greater transplant-free survival compared to patients with unresolved AKIN at both the 1-year (p = 0.04) and 3-year (p < 0.01) follow-ups. Conclusions: When evaluating clinical predictors of AKIN resolution in admitted patients with cirrhosis, our study showed that a higher admission albumin value and non-MASLD etiology of cirrhosis were associated with higher odds of AKIN resolution at the time of discharge. Conversely, a higher admission Cr value was associated with lower odds of AKIN resolution at the time of discharge. We also demonstrate that AKIN resolution during index admission was associated with improved short- and long-term transplant-free survival (up to 3 years). Our findings warrant external validation in larger cohorts to further evaluate the impact of inpatient AKI resolution on cirrhosis outcomes. Our findings can help clinicians predict AKIN outcomes and encourage more aggressive management of AKI, especially in high-risk patients, which can improve mortality.

Association of Preoperative Neutrophil to Lymphocyte Ratio with Early Postoperative Acute Kidney Injury Following Isolated Off-Pump Coronary Artery Bypass Grafting

Objective: Acute kidney injury (AKI) is a frequent complication after off-pump coronary artery bypass grafting (OPCAB) that complicates recovery, increases treatment cost and mortality. Neutrophil to lymphocyte ratio (NLR) is a systemic inflammatory marker easily derived from complete blood count that has many prognostic potentials. The purpose of this study was to evaluate if there is an association of preoperative NLR with early postoperative AKI following isolated OPCAB. Methods: This cross-sectional study was carried out in the Department of Cardiac Surgery, National Institute of Cardiovascular Diseases (NICVD) on a total of 60 patients aged 31-70 years with no preoperative renal dysfunction undergoing isolated OPCAB between August 2021 and July 2022. Group A included 30 patients with preoperative NLR &lt; 2.65 and Group B included 30 patients with preoperative NLR ≥ ≥≥2.65. Patients were monitored for development of early postoperative AKI according to serum creatinine criteria of Kidney Disease Improving Global Outcomes (KDIGO) 2012 guideline. Results: Two patients from group A and twenty patients from group B developed early postoperative AKI (p &lt; 0.001). Events of AKI were significantly higher in group B patients at all postoperative time points. Multivariate binary logistic regression analysis revealed preoperative NLR ≥ ≥≥2.65 as an independent predictor of early post OPCAB AKI (p = 0.004, OR = 13.746). In receiver operating curve (ROC) analysis area under curve (AUC) was 0.933 (95% CI 0.874-0.992, p &lt; 0.001). It showed 90.91% sensitivity and 73.7% specificity at the pre-set cut off value of NLR at 2.65 where optimal predictability of post-OPCAB AKI occurred with 66.67% positive predictive value, 93.33% negative predictive value and 80% accuracy. Conclusion: Preoperative NLR is significantly associated with early postoperative AKI following isolated OPCAB and therefore it should be incorporated in routine clinical practice for early prediction of AKI and implementing timely preventive strategies. (Bangladesh Heart Journal 2024; 39(2): 151-160

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

Continuous Urine Output-Based Alert Identifies Cardiac Surgery–associated Acute Kidney Injury Earlier Than Serum Creatinine: A Prospective and Retrospective Observational Study

Objective(s)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. We investigated the diagnostic performance of continuous UO, enabled by active drain line clearance, based alerts (Accuryn AKI Alert), compared to AKI stage 2 SCr criteria and their association to length of stay (LOS), need for continuous renal replacement therapy (CRRT), and 30-day mortality. DesignProspective and retrospective observational study. SettingNine tertiary centers. ParticipantsCardiac surgery patients. InterventionsNone. Measurements and Main Results522 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 to 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. 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. AKI Alert stage 1 was significantly associated with increased ICU and hospital LOS and CRRT, and stage ≥2 alert with mortality. ConclusionsAKI Alert based on continuous UO, enabled by active drain line clearance, detected AKI stages 1 and 2 before SCr. Early AKI detection allows for early kidney optimization, potentially improving patient outcomes.

#2317 Did acute kidney injury confer greater mortality in COVID-19 hospitalized patients? A Portuguese hospital experience in the third COVID wave

Abstract Background and Aims The outbreak of coronavirus disease 2019 (COVID-19) pandemic, which originated in December 2019, had a huge impact on healthcare worldwide. Numerous studies have reported alterations in kidney function among hospitalized patients with COVID-19, such as hematuria, proteinuria, and acute kidney injury (AKI). Histopathology exams in autopsies have identified various potential causes for the presence of AKI in these patients, with reports linking AKI to unfavorable outcomes across multiple countries. However, additional data concerning hospitalized COVID patients in Portugal are essential to further understand this aspect. Method Retrospective cohort study enrolling adult patients, who attended the Emergency Department and recorded positive polymerase chain reaction (PCR) results for SARS-CoV-2 from January 1 to January 31, 2021. AKI was diagnosed using the Kidney Disease Improving Global Outcome (KDIGO) classification based on serum creatinine (sCr) criteria and using a background creatinine available in the patient record. We performed an analysis of incidence, lethality, and possible risk factors of AKI in COVID-19 patients. Results The study encompassed a cohort of 239 patients, of whom 62 (25.94%) received a diagnosis of Acute Kidney Injury (AKI) based on KDIGO criteria. Within this subgroup, the average age was 77.65 years (±12.07), with a total of 29 male patients (46.78%). Notably, 30 deaths (48.39%) occurred during the hospital stay in this group. Regarding the AKI classification, 39 patients (62.9%) were classified as KDIGO-AKI stage 1, 14 patients (22.58%) as stage 2, and 9 patients (14.52%) as stage 3. Regarding the timing of the diagnosis of AKI, 54 (87%) occurred in the moment of admission, 7 patients (11.3%) were diagnosed within the first 48 hours and a solitary case (1.6%) was diagnosed after 7 days of hospitalization. In the non-AKI group, the mean age was 69.86 years (±15.95), and approximately 55% were male. Within this group, 49 deaths (27.7%) were recorded during hospitalization. Significantly higher mortality rates were observed in the AKI group, demonstrating a statistically significant difference (p &amp;lt; 0.01) and a relative risk of 1.75 or mortality during hospitalization for AKI patients. Furthermore, the duration of hospitalization was notably prolonged in the AKI group (p &amp;lt; 0.01), with a disparity of approximately three days. Individuals who developed AKI exhibited lower scores on the Barthel-dependence scale, indicative of higher dependence (p &amp;lt; 0.01), and were significantly older (p &amp;lt; 0.01) comparing with the ones that did not develop acute kidney injury. Additionally, it was remarkable that the leukocyte count at admission was more elevated in the AKI group (p = 0.03) compared to non-AKI patients with a difference of approximately 1.62×109/L. Conclusion Respiratory infections, including COVID-19, frequently lead to emergency department admissions and hospitalizations. This study validates an elevated prevalence of acute kidney injury (AKI) both at admission and during the hospital stay in such cases. The presence of AKI is linked to adverse outcomes, including mortality and extended hospital stays, underscoring the critical importance of promptly diagnosing AKI. Larger-scale studies are warranted in this field to enhance our understanding of this entity and therefore improve the outcomes related to this prevalent condition.

Acute kidney injury in children hospitalised for febrile urinary tract infection.

To determine (i) prevalence and the risk factors for acute kidney injury (AKI) in children hospitalised for febrile urinary tract infection (fUTI) and (ii) role of AKI as indicator of an underlying VUR. AKI, in fact, is favoured by a reduced nephron mass, often associated to VUR. This retrospective Italian multicentre study enrolled children aged 18 years or younger (median age = 0.5 years) discharged with a primary diagnosis of fUTI. AKI was defined using Kidney Disease/Improving Global Outcomes serum creatinine criteria. Of 849 children hospitalised for fUTI (44.2% females, median age 0.5 years; IQR = 1.8), 124 (14.6%) developed AKI. AKI prevalence rose to 30% in the presence of underlying congenital anomalies of the kidney and urinary tract (CAKUT). The strongest AKI predictors were presence of CAKUT (OR = 7.5; 95%CI: 3.8-15.2; p = 9.4e-09) and neutrophils levels (OR = 1.13; 95%CI: 1.08-1.2; p = 6.8e-07). At multiple logistic regression analysis, AKI during fUTI episode was a significant indicator of VUR (OR = 3.4; 95%CI: 1.7-6.9; p = 0.001) despite correction for the diagnostic covariates usually used to assess the risk of VUR after the first fUTI episode. Moreover, AKI showed the best positive likelihood ratio, positive predictive value, negative predictive value and specificity for VUR. AKI occurs in 14.6% of children hospitalised for fUTI and is a significant indicator of VUR.

Evaluation of risk stratification for acute kidney injury: a comparative analysis of EKFC, 2009 and 2021 CKD-EPI glomerular filtration estimating equations

BackgroundThe adoption of the 2021 CKD-EPIcr equation for glomerular filtration rate (GFR) estimation provided a race-free eGFR calculation. However, the discriminative performance for AKI risk has been rarely validated. We aimed to evaluate the differences in acute kidney injury (AKI) prediction or reclassification power according to the three eGFR equations.MethodsWe performed a retrospective observational study within a tertiary hospital from 2011 to 2021. Acute kidney injury was defined according to KDIGO serum creatinine criteria. Glomerular filtration rate estimates were calculated by three GFR estimating equations: 2009 and 2021 CKD-EPIcr, and EKFC. In three equations, AKI prediction performance was evaluated with area under receiver operator curves (AUROC) and reclassification power was evaluated with net reclassification improvement analysis.ResultsA total of 187,139 individuals, including 27,447 (14.7%) AKI and 159,692 (85.3%) controls, were enrolled. In the multivariable regression prediction model, the 2009 CKD-EPIcr model (continuous eGFR model 2, 0.7583 [0.755–0.7617]) showed superior performance in AKI prediction to the 2021 CKD-EPIcr (0.7564 [0.7531–0.7597], < 0.001) or EKFC model in AUROC (0.7577 [0.7543–0.761], < 0.001). Moreover, in reclassification of AKI, the 2021 CKD-EPIcr and EKFC models showed a worse classification performance than the 2009 CKD-EPIcr model. (− 7.24 [− 8.21–− 6.21], − 2.38 [− 2.72–− 1.97]).ConclusionRegarding AKI risk stratification, the 2009 CKD-EPIcr equation showed better discriminative performance compared to the 2021 CKD-EPIcr equation in the study population.Graphical abstract

Renal tissue oxygenation and development of AKI in preterm neonates born < 32 weeks' gestational age in the first week of age.

To evaluate the relationship between regional renal saturation of oxygen (RrSO2) changes and serum creatinine (SCr) during the first eight days of age for preterm neonates born < 32 weeks' gestational age. Post-hoc analysis of multicenter prospectively measured neonatal RrSO2 values collected during the first 8 days of age in neonates born at < 32 weeks' gestation. Acute kidney injury (AKI) was defined by the neonatal modified Kidney Disease: Improving Global Outcomes (KDIGO) criteria. Variables were compared between groups of neonates with and with AKI. One hundred nine neonates were included and 561 SCr values were obtained. Eight participants developed AKI by SCr criteria. A 10-percentage point increase in mean %RrSO2 was associated with a 40% decrease in risk of AKI (95%CI: 9.6-61%; p = 0.016). Increases in mean %RrSO2 in neonates born at < 32 weeks' GA were associated with a decreased risk of AKI. These findings support the design of further prospective trials utilizing RrSO2 monitoring to evaluate new therapies or clinical protocols to prevent and treat neonatal AKI.

The effect of dehydration, hyperchloremia and volume of fluid resuscitation on acute kidney injury in children admitted to hospital with diabetic ketoacidosis.

Acute kidney injury (AKI) is a recognized comorbidity in pediatric diabetic ketoacidosis (DKA), although the exact etiology is unclear. The unique physiology of DKA makes dehydration assessments challenging, and these patients potentially receive excessive amounts of intravenous fluids (IVF). We hypothesized that dehydration is over-estimated in pediatric DKA, leading to over-administration of IVF and hyperchloremia that worsens AKI. Retrospective cohort of all DKA inpatients at a tertiary pediatric hospital from 2014 to 2019. A total of 145 children were included; reasons for exclusion were pre-existing kidney disease or incomplete medical records. AKI was determined by change in creatinine during admission, and comparison to a calculated baseline value. Linear regression multivariable analysis was used to identify factors associated with AKI. True dehydration was calculated from patients' change in weight, as previously validated. Fluid over-resuscitation was defined as total fluids given above the true dehydration. A total of 19% of patients met KDIGO serum creatinine criteria for AKI on admission. Only 2% had AKI on hospital discharge. True dehydration and high serumurea levels were associated with high serumcreatinine levels on admission (p = 0.042; p < 0.001, respectively). Fluid over-resuscitation and hyperchloremia were associated with delayed kidney recovery (p < 0.001). Severity of initial AKI was associated with cerebral edema (p = 0.018). Dehydration was associated with initial AKI in children with DKA. Persistent AKI and delay to recovery was associated with hyperchloremia and over-resuscitation with IVF, potentially modifiable clinical variables for earlier AKI recovery and reduction in long-term morbidity. This highlights the need to re-address fluid protocols in pediatric DKA.

Nephrology consultation improves the clinical outcomes of patients with acute kidney injury.

Acute kidney injury (AKI) is prevalent in critically ill patients and is associated with an increased risk of in-hospital mortality. Nephrology consultation may be protective, but this has rarely been evaluated in South Korea. This multicenter retrospective study was based on the electronic medical records (EMRs) of two third-affiliated hospitals. We extracted the records of patients admitted to intensive care units (ICUs) between 2011 and 2020, and retrospectively detected AKI using the modified serum creatinine criteria of the Kidney Disease: Improving Global Outcomes (KDIGO) guidelines. The AKI diagnosis date was defined as the first day of a significant change in serum creatinine level (≥0.3 mg/dL) within 48 hours. Nephrology consultation status was retrieved from the EMRs. In total, 2,461 AKI patients were included; the median age was 65 years (interquartile range [IQR], 56-75 years), 1,459 (59.3%) were male, and 1,065 (43.3%) were of AKI stage 3. During a median of 5 days (IQR, 3-11 days) of ICU admission, nephrology consultations were provided to 512 patients (20.8%). Patients who received such consultations were older, had more comorbidities, and more commonly required dialysis. In a multivariable model, nephrology consultation reduced the risk of in-hospital mortality by 30% (hazard ratio, 0.71; 95% confidence interval, 0.57-0.88). Other factors significant for in-hospital mortality were older age, a higher sequential organ failure assessment (SOFA) score, sepsis, diabetes, hypertension, heart disease, and cancer. For AKI patients in ICUs, nephrology consultation reduced the risk of in-hospital mortality, particularly among those with multiple comorbidities. Therefore, nephrology consultation should not be omitted during ICU care.

Processes of Care After Hospital Discharge for Survivors of Acute Kidney Injury: A Population-Based Cohort Study

Survivors of acute kidney injury (AKI) are at high risk of adverse outcomes. Monitoring of kidney function, screening for proteinuria, use of statins and renin-angiotensin-aldosterone system (RAAS) inhibitors, and nephrology follow-up among survivors have not been fully characterized. We examined these processes of care after discharge in survivors of hospitalized AKI. Population-based retrospective cohort study. Adults in Alberta, Canada, admitted to the hospital between 2009 and 2017, then followed from their discharge date until 2019 for a median follow-up of 2.7 years. Hospital-acquired AKI diagnostically conforming to Kidney Disease: Improving Global Outcomes (KDIGO) serum creatinine criteria for stage 2 or stage 3 disease, or the need for acute dialysis. Outcomes after hospital discharge included the proportion of participants who had evaluation of kidney function, were seen by a specialist or general practitioner, and received postdischarge prescriptions for recommended medications for chronic kidney disease (CKD). Cumulative incidence curves to characterize the proportion of participants who received each process of care outcome within the first 90 days and subsequent 1-year follow-up period after hospital discharge. To avoid risks associated with multiple hypothesis testing, differences were not statistically compared across groups. The cohort (n=23,921) included 50.2% men (n=12,015) with a median age of 68.1 [IQR, 56.9-78.8] years. Within 90 days after discharge, 21.2% and 8.6% of patients with and without pre-existing CKD, respectively, were seen by a nephrologist; 60.1% of AKI survivors had at least 1 serum creatinine measured, but only 25.5% had an assessment for albuminuria within 90 days after discharge; 52.7% of AKI survivors with pre-existing CKD, and 51.6% with de novo CKD were prescribed a RAAS inhibitor within 4-15 months after discharge. Retrospective data were collected as part of routine clinical care. The proportion of patients receiving optimal care after an episode of AKI in Alberta was low and may represent a target for improving long-term outcomes for this population. A study in Alberta, Canada, examined the care received by patients with acute kidney disease (AKI) during hospitalization and after discharge between 2007 and 2019. The results showed that a low proportion of patients with moderate to severe AKI were seen by a kidney specialist during hospitalization or within 90 days after discharge. Fewer than 25% of AKI patients had their kidney function monitored with both blood and urine tests within 90 days of discharge. Additionally, about half of AKI survivors with chronic kidney disease (CKD) were prescribed guideline recommended medications for CKD within 15 months after discharge. There is potential to improve health care delivery to these patients both in hospital and after hospital discharge.

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 deep learning–based dynamic model for predicting acute kidney injury risk severity in postoperative patients

BackgroundAcute kidney injury is a common postoperative complication affecting between 10% and 30% of surgical patients. Acute kidney injury is associated with increased resource usage and chronic kidney disease development, with more severe acute kidney injury suggesting more aggressive deterioration in clinical outcomes and mortality. MethodsWe considered 42,906 surgical patients admitted to University of Florida Health (n = 51,806) between 2014 and 2021. Acute kidney injury stages were determined using the Kidney Disease Improving Global Outcomes serum creatinine criteria. We developed a recurrent neural network–based model to continuously predict acute kidney injury risk and state in the following 24 hours and compared it with logistic regression, random forest, and multi-layer perceptron models. We used medications, laboratory and vital measurements, and derived features from past one-year records as inputs. We analyzed the proposed model with integrated gradients for enhanced explainability. ResultsPostoperative acute kidney injury at any stage developed in 20% (10,664) of the cohort. The recurrent neural network model was more accurate in predicting nearly all categories of next-day acute kidney injury stages (including the no acute kidney injury group). The area under the receiver operating curve and 95% confidence intervals for recurrent neural network and logistic regression models were for no acute kidney injury (0.98 [0.98–0.98] vs 0.93 [0.93–0.93]), stage 1 (0.95 [0.95–0.95] vs. 0.81 [0.80–0.82]), stage 2/3 (0.99 [0.99–0.99] vs 0.96 [0.96–0.97]), and stage 3 with renal replacement therapy (1.0 [1.0–1.0] vs 1.0 [1.0–1.0]. ConclusionThe proposed model demonstrates that temporal processing of patient information can lead to more granular and dynamic modeling of acute kidney injury status and result in more continuous and accurate acute kidney injury prediction. We showcase the integrated gradients framework’s utility as a mechanism for enhancing model explainability, potentially facilitating clinical trust for future implementation.

A case of abdominal distress and kidney dysfunction in a patient with diabetes.

A 65-year-old male with diabetes mellitus and dyslipidemia presented with a fever and dysuria for the past week. He developed hematuria, lower abdominal discomfort, and constipation. During examination, tachycardia (120 beats per min) and relative hypotension (96/57 mmHg) were observed. Laboratory tests revealed acute kidney injury with metabolic acidosis (serum creatinine of 5.47 mg/dL, pH value 7.29 BE: −7.7). Kidney, ureter, and bladder imaging showed bladder distension with gas formation (Figure 1). An abdominal computed tomography scan revealed emphysematous cystitis (Figure 2). The patient was initially treated with foley irrigation and antibiotics, but he developed respiratory distress on the same day and was intubated for urosepsis. Blood and urine cultures showed Klebsiella pneumoniae. He received temporary hemodialysis due to refractory fluid overload and Kidney Disease Improving Global Outcomes (KDIGO) stage III acute kidney injury by serum creatinine criteria during hospitalization. Emphysematous urinary tract infections (UTIs) involve gas formation in the urinary tract and are commonly caused by Escherichia coli or Klebsiella pneumoniae, particularly in individuals with diabetes.1 Emphysematous cystitis is a rare type of UTI characterized by gas formation in the bladder wall. The symptoms include abdominal pain, dysuria, and pneumaturia. The diagnosis is made through imaging, and treatment involves antibiotics.2 In severe cases, hospitalization may be required. Emphysematous cystitis is a rare but serious complication of UTIs, particularly in individuals with diabetes. Early diagnosis and appropriate management, including antibiotics and surgical therapy, if necessary, are essential for improving outcomes.3 Patients or the public were not involved in the design, conduct, reporting, or dissemination plans of our research.

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.

Acute kidney injury biomarker olfactomedin 4 predicts furosemide responsiveness.

Acute kidney injury (AKI) is associated with increased morbidity and mortality in critically ill patients. Olfactomedin 4 (OLFM4), a secreted glycoprotein expressed in neutrophils and stressed epithelial cells, is upregulated in loop of Henle (LOH) cells following AKI. We hypothesized that urine OLFM4 (uOLFM4) will increase in patients with AKI and may predict furosemide responsiveness. Urine from critically ill children was collected prospectively and tested for uOLFM4 concentrations with a Luminex immunoassay. Severe AKI was defined by KDIGO (stage 2/3) serum creatinine criteria. Furosemide responsiveness was defined as > 3mL/kg/h of urine output in the 4h after a 1mg/kg IV furosemide dose administered as part of standard of care. Fifty-seven patients contributed 178 urine samples. Irrespective of sepsis status or AKI cause, uOLFM4 concentrations were higher in patients with AKI (221ng/mL [IQR 93-425] vs. 36ng/mL [IQR 15-115], p = 0.007). uOLFM4 concentrations were higher in patients unresponsive to furosemide (230ng/mL [IQR 102-534] vs. 42ng/mL [IQR 21-161], p = 0.04). Area under the receiver operating curve for association with furosemide responsiveness was 0.75 (95% CI, 0.60-0.90). AKI is associated with increased uOLFM4. Higher uOLFM4 is associated with a lack of response to furosemide. Further testing is warranted to determine whether uOLFM4 could identify patients most likely to benefit from earlier escalation from diuretics to kidney replacement therapy to maintain fluid balance. A higher resolution version of the Graphical abstract is available as Supplementary information.

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.

Intraoperative renal desaturation and postoperative acute kidney injury in older patients undergoing liver resection: A prospective cohort study

Study objectiveTo determine the association between intraoperative renal tissue desaturation as measured using near-infrared spectroscopy and increased likelihood of developing postoperative acute kidney injury (AKI) in older patients undergoing hepatectomy. DesignA multicenter prospective cohort study. SettingThe study was conducted at two tertiary hospitals in China from September 2020 to October 2021. Patients157 older patients (≥ 60 years) undergoing open hepatectomy surgery. Interventions and measurementsRenal tissue oxygen saturation was continuously monitored during operation using near-infrared spectroscopy. The exposure of interest was intraoperative renal desaturation, defined as at least 20% relative decline in renal tissue oxygen saturation from baseline. The primary outcome was postoperative AKI, defined using the Kidney Disease: Improving Global Outcomes criteria according to the serum creatinine criteria. Main resultsRenal desaturation occurred in 70 of 157 patients. Postoperative AKI was observed in 23% (16/70) and 8% (7/87) of patients with versus without renal desaturation. Patients with renal desaturation were at higher risk of AKI than patients without renal desaturation (adjusted odds ratio 3.41, 95% confidence interval: 1.12–10.36, p = 0.031). Predictive performance was 65.2% sensitivity and 33.6% specificity for hypotension alone, 69.6% sensitivity and 59.7% specificity for renal desaturation alone, and 95.7% sensitivity and 26.9% specificity for combined use of hypotension and renal desaturation. ConclusionsIntraoperative renal desaturation occurred in >40% in our sample of older patients undergoing liver resection and was associated with increased risk of AKI. Intraoperative near-infrared spectroscopy monitoring enhances the detection of AKI.

Acute kidney injury in autologous hematopoietic stem cell transplant for patients with lymphoma – KDIGO classification with creatinine and urinary output criteria: a cohort analysis

Eligibility and indication for autologous hematopoietic stem cell transplantation (HSCT) in patients with lymphoma are increasing. Acute kidney injury (AKI) is a known complication of HSCT with studies including a miscellaneous of hematological diagnoses and using different definitions of AKI. We aimed to evaluate incidence, risk factors and prognostic impact of AKI post-HSCT in patients with lymphoma submitted to autologous HSCT using the KDIGO classification with both serum creatinine and urinary output criteria. We performed a single-center retrospective cohort study including patients with lymphoma admitted for autologous HSCT. We used survival analysis with competing risks to evaluate cumulative incidence of AKI, AKI risk factors and AKI impact on disease-free survival. We used Cox regression for impact of AKI on overall survival. We used backward stepwise regression to create multivariable models. A total of 115 patients were included. Cumulative incidence of AKI: 63.7% 100 d post-HSCT. First diagnosis criteria: creatinine in 54.8%, urinary output in 41.1% and both in 4.1%. AKI highest stage: 1 in 57.5%, 2 in 17.8% and 3 in 24.7%. Variables independently associated with higher incidence of AKI were: use of nephrotoxic drugs (HR: 2.87, 95% CI: 1.07–7.65; p = 0.035), mucositis (HR: 1.95, 95% CI: 1.16–3.29; p = 0.012) and shock (HR: 2.63, 95% CI: 1.19–5.85; p = 0.017). Moderate to severe AKI was independently associated with lower overall survival (HR: 2.04, 95% CI: 1.06–3.94; p = 0.033). No association with relapse nor progression to chronic kidney disease (CKD) was found. AKI affects almost two thirds of patients with lymphomas submitted to autologous HSCT. Nephrotoxic drugs, mucositis and shock are important independent AKI risk factors. More than one third of AKI episodes are moderate to severe and these are associated with lower overall survival.