Creatinine-based definitions: from baseline creatinine to serum creatinine adjustment in intensive care

Development and external validation of a nomogram for the early prediction of acute kidney injury in septic patients: a multicenter retrospective clinical study

Background and purpose: Acute kidney injury (AKI) is a common serious complication in sepsis patients with a high mortality rate. This study aimed to develop and validate a predictive model for sepsis associated acute kidney injury (SA-AKI). Methods: In our study, we retrospectively constructed a development cohort comprising 733 septic patients admitted to eight Grade-A tertiary hospitals in Shanghai from January 2021 to October 2022. Additionally, we established an external validation cohort consisting of 336 septic patients admitted to our hospital from January 2017 to December 2019. Risk predictors were selected by LASSO regression, and a corresponding nomogram was constructed. We evaluated the model's discrimination, precision and clinical benefit through receiver operating characteristic (ROC) curves, calibration plots, decision curve analysis (DCA) and clinical impact curves (CIC) in both internal and external validation. Results: AKI incidence was 53.2% in the development cohort and 48.2% in the external validation cohort. The model included five independent indicators: chronic kidney disease stages 1 to 3, blood urea nitrogen, procalcitonin, D-dimer and creatine kinase isoenzyme. The AUC of the model in the development and validation cohorts was 0.914 (95% CI, 0.894-0.934) and 0.923 (95% CI, 0.895-0.952), respectively. The calibration plot, DCA, and CIC demonstrated the model's favorable clinical applicability. Conclusion: We developed and validated a robust nomogram model, which might identify patients at risk of SA-AKI and promising for clinical applications.

Biomarkers of acute kidney injury: From discovery to the future of clinical practice

Purpose of this review Acute kidney injury (AKI) is a complex syndrome whose development is associated with an increased morbidity and mortality. Recent studies show that this syndrome is a common complication in critically ill and surgical patients the trajectory of which may differ. As AKI can be induced by different triggers, it is complex and therefore challenging to manage patients with AKI. This review strives to provide a brief historical perspective on AKI, elucidate recent developments in diagnosing and managing AKI, and show the current usage of novel biomarkers in both clinical routine and research. In addition, we provide a perspective on potential future developments and their impact of AKI understanding and management. Recent findings/developments Recent studies show the merits of stress and damage biomarkers, highlighting limitations of the current KDIGO definition that only uses the functional biomarkers serum creatinine and urine output. The use of novel biomarkers led to the introduction of the concept of "subclinical AKI". This new classification may allow a more distinct management of affected or at risk patients. Ongoing studies, such as BigpAK-2 and PrevProgAKI, investigate the implementation of biomarker-guided interventions in clinical practice and may demonstrate an improvement in patients' outcome. Summary The ongoing scientific efforts surrounding AKI have deepened our understanding of the syndrome prompting an expansion of existing concepts. A future integration of stress and damage biomarkers in AKI management, may lead to an individualized therapy in this area.

How a positive fluid balance develops in acute kidney injury: A binational, observational study

PURPOSE

A positive fluid balance (FB) is associated with harm in intensive care unit (ICU) patients with acute kidney injury (AKI). We aimed to understand how a positive balance develops in such patients.

METHODS

Multinational, retrospective cohort study of critically ill patients with AKI not requiring renal replacement therapy.

RESULTS

AKI occurred at a median of two days after admission in 7894 (17.3%) patients. Cumulative FB became progressively positive, peaking on day three despite only 848 (10.7%) patients receiving fluid resuscitation in the ICU. In those three days, persistent crystalloid use (median:60.0 mL/h; IQR 28.9-89.2), nutritional intake (median:18.2 mL/h; IQR 0.0-45.9) and limited urine output (UO) (median:70.8 mL/h; IQR 49.0-96.7) contributed to a positive FB. Although UO increased each day, it failed to match input, with only 797 (10.1%) patients receiving diuretics in ICU. After adjustment, a positive FB four days after AKI diagnosis was associated with an increased risk of hospital mortality (OR 1.12;95% confidence intervals 1.05-1.19;p-value <0.001).

CONCLUSION

Among ICU patients with AKI, cumulative FB increased after diagnosis and was associated with an increased risk of mortality. Continued crystalloid administration, increased nutritional intake, limited UO, and minimal use of diuretics all contributed to positive FB.

KEY POINTS

Question How does a positive fluid balance develop in critically ill patients with acute kidney injury? Findings Cumulative FB increased after AKI diagnosis and was secondary to persistent crystalloid fluid administration, increasing nutritional fluid intake, and insufficient urine output. Despite the absence of resuscitation fluid and an increasing cumulative FB, there was persistently low diuretics use, ongoing crystalloid use, and a progressive escalation of nutritional fluid therapy. Meaning Current management results in fluid accumulation after diagnosis of AKI, as a result of ongoing crystalloid administration, increasing nutritional fluid, limited urine output and minimal diuretic use.

Attributable mortality of acute kidney injury among critically ill patients with sepsis: a multicenter, retrospective cohort study

BACKGROUND

Sepsis and acute kidney injury (AKI) are common severe diseases in the intensive care unit (ICU). This study aimed to estimate the attributable mortality of AKI among critically ill patients with sepsis and to assess whether AKI was an independent risk factor for 30-day mortality.

METHODS

The information we used was derived from a multicenter prospective cohort study conducted in 18 Chinese ICUs, focusing on septic patients post ICU admission. The patients were categorized into two groups: those who developed AKI (AKI group) within seven days following a sepsis diagnosis and those who did not develop AKI (non-AKI group). Using propensity score matching (PSM), patients were matched 1:1 as AKI and non-AKI groups. We then calculated the mortality rate attributable to AKI in septic patients. Furthermore, a survival analysis was conducted comparing the matched AKI and non-AKI septic patients. The primary outcome of interest was the 30-day mortality rate following the diagnosis of sepsis.

RESULTS

Out of the 2175 eligible septic patients, 61.7% developed AKI. After the application of PSM, a total of 784 septic patients who developed AKI were matched in a 1:1 ratio with 784 septic patients who did not develop AKI. The overall 30-day attributable mortality of AKI was 6.6% (95% CI 2.3 ∼ 10.9%, p = 0.002). A subgroup analysis revealed that the 30-day attributable mortality rates for stage 1, stage 2, and stage 3 AKI were 0.6% (95% CI -5.9 ∼ 7.2%, p = 0.846), 4.7% (95% CI -3.1 ∼ 12.4%, p = 0.221) and 16.8% (95% CI 8.1 ∼ 25.2%, p < 0.001), respectively. Particularly noteworthy was that stage 3 AKI emerged as an independent risk factor for 30-day mortality, possessing an adjusted hazard ratio of 1.80 (95% CI 1.31 ∼ 2.47, p < 0.001).

CONCLUSIONS

The overall 30-day attributable mortality of AKI among critically ill patients with sepsis was 6.6%. Stage 3 AKI had the most significant contribution to 30-day mortality, while stage 1 and stage 2 AKI did not increase excess mortality.

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

BACKGROUND

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.

METHODS

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.

RESULTS

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).

CONCLUSIONS

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.

Association between renal surface nodularity and increased adverse vascular event risk in patients with arterial hypertension

OBJECTIVE

To explore the association of renal surface nodularity (RSN) with the increased adverse vascular event (AVE) risk in patients with arterial hypertension.

METHODS

This cross-sectional study included patients with arterial hypertension aged 18-60 years who underwent contrasted computed tomography (CT) of kidney from January 2012 to December 2020. The subjects were classified into AVE or not (non-AVE) matched with age (≤5 years) and sex. Their CT images were analyzed using both qualitative (semiRSN) and quantitative RSN (qRSN) methods, respectively. Their clinical characteristics included age, sex, systolic blood pressure (SBP), diastolic blood pressure, hypertension course, diabetes history, hyperlipidemia, and estimated glomerular filtration rate (eGFR).

RESULTS

Compared with non-AVE group (n = 91), AVE (n = 91) was at lower age, higher SBP, and fewer rate of diabetes and hyperlipidemia history (all P < .01). Rate of positive semiRSN was higher in AVE than non-AVE (49.45% vs 14.29%, P < .001). qRSN was larger in AVE than non-AVE [1.03 (0.85, 1.33) vs 0.86 (0.75,1.03), P < .001]. The increased AVE was associated with semiRSN (odds ratio = 7.04, P < .001) and qRSN (odds ratio = 5.09, P = .003), respectively. For distinguishing AVE from non-AVE, the area under receiver operating characteristic was bigger in the models combining the clinical characteristics with either semiRSN or qRSN than that of semiRSN or qRSN alone (P ≤.01).

CONCLUSION

Among the patients with arterial hypertension aged 18-60 years, CT imaging-based RSN was associated with increased AVE risk.

Early acute kidney injury and transition to renal replacement therapy in critically ill patients with SARS-CoV-2 requiring veno-venous extracorporeal membrane oxygenation

BACKGROUND

Critically ill patients with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) requiring veno-venous extracorporeal membrane oxygenation (vv-ECMO) are at risk for acute kidney injury (AKI). Currently, the incidence of AKI and progression to kidney replacement therapy (RRT) in critically ill patients with vv-ECMO for severe COVID-19 and implications on outcome are still unclear.

METHODS

Retrospective analysis at the University Medical Center Hamburg-Eppendorf (Germany) between March 1st, 2020 and July 31st, 2021. Demographics, clinical parameters, AKI, type of organ support, length of ICU stay, mortality and severity scores were assessed.

RESULTS

Ninety-one critically ill patients with SARS-CoV-2 requiring ECMO were included. The median age of the study population was 57 (IQR 49-64) years and 67% (n = 61) were male. The median SAPS II and SOFA Score on admission were 40 (34-46) and 12 (10-14) points, respectively. We observed that 45% (n = 41) developed early-AKI, 38% (n = 35) late-AKI and 16% (n = 15) no AKI during the ICU stay. Overall, 70% (n = 64) of patients required RRT during the ICU stay, 93% with early-AKI and 74% with late-AKI. Risk factors for early-AKI were younger age (OR 0.94, 95% CI 0.90-0.99, p = 0.02) and SAPS II (OR 1.12, 95% CI 1.06-1.19, p < 0.001). Patients with and without RRT were comparable regarding baseline characteristics. SAPS II (41 vs. 37 points, p < 0.05) and SOFA score (13 vs. 12 points, p < 0.05) on admission were significantly higher in patients receiving RRT. The median duration of ICU (36 vs. 28 days, p = 0.27) stay was longer in patients with RRT. An ICU mortality rate in patients with RRT in 69% (n = 44) and in patients without RRT of 56% (n = 27) was observed (p = 0.23).

CONCLUSION

Critically ill patients with severe SARS-CoV-2 related ARDS requiring vv-ECMO are at high risk of early acute kidney injury. Early-AKI is associated with age and severity of illness, and presents with high need for RRT. Mortality in patients with RRT was comparable to patients without RRT.

Impact of dexmedetomidine on mortality in critically ill patients with acute kidney injury: a retrospective propensity score matching analysis

OBJECTIVES

This study sought to estimate the effect of dexmedetomidine (DEX) administration on mortality in critically ill patients with acute kidney injury (AKI).

DESIGN

A retrospective cohort study.

SETTING

The study sourced its data from the Multiparameter Intelligent Monitoring in Intensive Care Database IV (MIMIC-IV), a comprehensive database of intensive care unit patients.

PARTICIPANTS

A total of 15 754 critically ill patients with AKI were enrolled from the MIMIC-IV database.

PRIMARY AND SECONDARY OUTCOME

Primary outcome was in-hospital mortality and secondary outcome was 180-day mortality.

RESULTS

15 754 critically ill AKI patients were included in our analysis. We found that DEX use decreased in-hospital mortality risk by 38% (HR 0.62, 95% CI 0.55 to 0.70) and 180-day mortality risk by 23% (HR 0.77, 95% CI 0.69 to 0.85). After adjusting for confounding factors, DEX can reduce all three stages of AKI in in-hospital mortality.

CONCLUSIONS

Our retrospective cohort study suggests that DEX significantly correlates with decreased risk-adjusted in-hospital and 180-day mortality in critically ill AKI patients. Nonetheless, future randomised controlled trials are warranted to validate our findings.

Update on persistent acute kidney injury in critical illnesses

Acute kidney injury (AKI) affects about half of patients admitted to the intensive care unit (ICU), and worsens their short- and long-term outcomes. Apparently self-limiting AKI episodes initiate a progression toward chronic kidney disease (CKD) through cellular and molecular mechanisms that are yet to be explained. In particular, persistent AKI, defined in 2016 by the Acute Dialysis Quality Initiative as an AKI which lasts more than 48 h from its onset, has been correlated with higher morbidity and mortality, and with a higher progression to acute kidney disease (AKD) and CKD than transient AKI (i.e. AKI with a reversal within 48 h). This classification has been also used in the setting of solid organ transplantation, demonstrating similar outcomes. Due to its incidence and poor prognosis and because prompt interventions seem to change its course, persistent AKI should be recognized early and followed-up also after its recovery. However, while AKI and CKD are well-described syndromes, persistent AKI and AKD are relatively new entities. The purpose of this review is to highlight the key phases of persistent AKI in ICU patients in terms of both clinical and mechanistic features in order to offer to clinicians and researchers an updated basis from which to start improving patients' care and direct future research.

Endotoxin removal therapy with Polymyxin B immobilized fiber column: a single center experience from EUPHAS2 registry

Although the precise clinical indication for initiation of PMX-HA is widely debated in the literature, a proper patient selection and timing of treatment delivery might play a critical role in the clinical course of a specific subphenotype of septic shock (endotoxic shock). In light of this view, since 2019, we have introduced in our clinical practice a diagnostic-therapeutic flowchart to select patients that can benefit the most from the treatment proposed. In addition, we reported in this study our experience of PMX-HA in a cohort of critically ill patients admitted to our intensive care unit (ICU). We analyzed a single centre, retrospective, observational web-based database (extracted from the EUPHAS2 registry) of critically ill patients admitted to the ICU between January 2016 and May 2021 who were affected by endotoxic shock. Patients were divided according to the diagnostic-therapeutic flowchart in two groups: Pre-Flowchart (Pre-F) and Post-Flowchart (Post-F). From January 2016 to May 2021, 61 patients were treated with PMX-HA out of 531 patients diagnosed with septic shock and of these, fifty patients (82%) developed AKI during their ICU stay. The most common source of infection was secondary peritonitis (36%), followed by community-acquired pneumonia (29%). Fifty-five (90%) out of 61 patients received a second PMX-HA treatment, with a statistically significant difference between the two groups (78% of the Pre-F vs. 100% of the Post-F group, p = 0.005). In both groups, between T0 and T120, the Endotoxin Activity Assay (EAA) decreased, while the SOFA score, mean arterial pressure (MAP), and Vasoactive Inotropic Score (VIS) improved with no statistically significant difference. Furthermore, when performing a propensity score matching analysis to compare mortality between the two groups, statistically significant lower ICU and 90-day mortalities were observed in the Post-F group [p = 0.016]. Although in this experienced centre data registry, PMX-HA was associated with organ function recovery, hemodynamic improvement, and current EAA level reduction in critically ill patients with endotoxic shock. Following propensity score-matched analysis, ICU mortality and 90-day mortalities were lower in the diagnostic-therapeutic flowchart group when considering two temporal groups based on strict patient selection criteria and timing to achieve PMX. Further Randomised Control Trials focused on centre selection, adequate training and a flowchart of action when assessing extracorporeal blood purification use should be performed.

Long-term kidney outcomes after leptospirosis: a prospective multicentre cohort study in Thailand

BACKGROUND

Leptospirosis is one of the most important public-health zoonotic diseases in the tropics that can cause severe organ dysfunction and death. Currently there are insufficient data on long-term renal dysfunction in patients after leptospirosis infection.

METHODS

A prospective multicentre cohort study was conducted at 15 hospitals in the Sisaket province of Thailand. Confirmed leptospirosis patients admitted from 1 December 2015 to 30 November 2018 were followed between 1 February 2020 and 31 October 2020 (median 4.1 years after hospital discharge). The primary outcome was a composite of major kidney adverse events (MAKEs) including all-cause mortality, dialysis and new-onset chronic kidney disease (CKD).

RESULTS

Of the 217 confirmed leptospirosis cases enrolled, 32.7% were classified as having severe leptospirosis. Fifteen cases (6.9%) were deceased at the time of hospital admission. After a median follow-up time of 4.18 years, 30 patients had died and 33 patients developed CKD. Patients with severe leptospirosis had a significantly higher risk of MAKEs {adjusted hazard ratio 2.45 [95% confidence interval (CI) 1.44-4.18]}. Patients with intensive care unit admission, pulmonary haemorrhage and acute kidney injury also had a higher risk of MAKEs and all-cause mortality. Participants with severe leptospirosis in the follow-up cohort showed a higher risk of developing CKD compared with non-severe leptospirosis [adjusted odds ratio 3.22 (95% CI 1.04-9.96)], especially renal magnesium and phosphate wasting.

CONCLUSION

Leptospirosis patients, especially severe leptospirosis, are associated with long-term kidney sequelae. Our finding reflects the importance of long-term follow-up and the urgent need for specific interventions.

Association between Premorbid Renin-Angiotensin-Aldosterone System Blockade and the Risk of Acute Kidney Injury in Critically Ill Patients

Background

Angiotensin-converting enzyme inhibitors (ACEis) and angiotensin receptor blockers (ARBs) are commonly used for hypertension and cardiovascular diseases. However, whether their use increases the risk of acute kidney injury (AKI) and should be discontinued during acute illness remains controversial.

Methods

This retrospective study enrolled 952 dialysis-free patients who were admitted to intensive care units (ICUs) between 2015 and 2017, including 476 premorbid long-term (> 1 month) ACEi/ARB users. Propensity score matching was performed to adjust for age, gender, comorbidities, and disease severity. The primary endpoint was the occurrence of AKI during hospitalization, and the secondary endpoint was mortality or dialysis within 1 year.

Results

Compared with non-users, the ACEi/ARB users were not associated with an increased AKI risk during hospitalization [66.8% vs. 70.4%; hazard ratio (HR): 1.13, 95% confidence interval (CI): 0.97-1.32, p = 0.126]. However, the ACEi/ARB users with sepsis (HR: 1.29, 95% CI: 1.04-1.60, p = 0.021) or hypotension (HR: 1.21, 95% CI: 1.02-1.14, p = 0.034) were found to have an increased AKI risk in subgroup analysis. Nevertheless, compared with the non-users, the ACEi/ARB users were associated with a lower incidence of mortality or dialysis within 1 year (log-rank p = 0.011).

Conclusions

Premorbid ACEi/ARB usage did not increase the incidence of AKI, and was associated with a lower 1-year mortality and dialysis rate in patients admitted to ICUs. Regarding the results of subgroup analysis, renin-angiotensin-aldosterone system blockade may still be safe and beneficial in the absence of sepsis or circulation failure. Further large-scale studies are needed to confirm our findings.

A Critical Reassessment of the Kidney Risk Caused by Tetrastarch Products in the Perioperative and Intensive Care Environments

Purpose: To reassess the results of former meta-analyses focusing on the relationship between novel HES preparations (130/0.4 and 130/0.42) and acute kidney injury. Previous meta-analyses are based on studies referring to partially or fully unpublished data or data from abstracts only. Methods: The studies included in the former meta-analyses were scrutinized by the authors independently. We completed a critical analysis of the literature, including the strengths, weaknesses and modifiers of the studies when assessing products, formulations and outcomes. Results: Both the published large studies and meta-analyses show significant bias in the context of the deleterious effect of 6% 130/0.4-0.42 HES. Without (1) detailed hemodynamic data, (2) the exclusion of other nephrotoxic events and (3) a properly performed evaluation of the dose-effect relationship, the AKI-inducing property of 6% HES 130/0.4 or 0.42 should not be considered as evidence. The administration of HES is safe and effective if the recommended dose is respected. Conclusions: Our review suggests that there is questionable evidence for the deteriorating renal effect of these products. Further well-designed, randomized and controlled trials are needed. Additionally, conclusions formulated for resource-rich environments should not be extended to more resource-scarce environments without proper qualifiers provided.

Association of renal surface nodularity with arterial hypertension compared to normotensive patients

BACKGROUND

Renal surface nodularity (RSN) is a subclinical biomarker of renal injury and may be associated with arterial hypertension.

PURPOSE

To explore the association of RSN with arterial hypertension compared to normotensive patients.

MATERIAL AND METHODS

A total of 205 inpatients with or without high blood pressure (HBP vs. control group) who underwent abdominal computed tomography (CT) scans were included. Their clinical characteristics included age, sex, HBP course, HBP grade, history of diabetes mellitus (DM), and renal function (estimated glomerular filtration rate [eGFR]). The HBP group included HBP/+DM and HBP/-DM based on the presence or absence of DM. The CT-based RSN grade was scored from 0 to 2 by two radiologists, respectively, where RSN grade 0 indicated smooth renal surface, grade 1 was mild RSN, and grade 2 was marked RSN.

RESULTS

The inter-rater agreement on RSN was good (Kappa = 0.76). The age-specific rate of RSN grade 1-2 was bigger in the HBP group than in the control group (42.86% [40%-49.22%] vs. 2.18% [0.00%-22.5%]; P = 0.005). RSN grade was associated with HBP course (P < 0.02). The rates of RSN grade 1-2 and of RSN grade 2 were bigger in the HBP/+DM group than those in the HBP/-DM group (48.84% vs. 37.84%, and 18.61% vs. 1.35%, respectively; all P = 0.001). Neither HBP course nor HBP grade correlated with rate of RSN grade (P > 0.05). The eGFR was similar among the RSN grades in HBP or between the HBP and control groups (P > 0.05).

CONCLUSION

RSN was associated with HBP compared to normotensive patients.

Kinetics of the Cell Cycle Arrest Biomarkers (TIMP2 and IGFBP7) for the Diagnosis of Acute Kidney Injury in Critically Ill COVID-19 Patients

BACKGROUND

Acute kidney injury (AKI) is highly prevalent in critical COVID-19 patients. The diagnosis and staging of AKI are based on serum creatinine (sCr) and urinary output criteria, with limitations in the functional markers. New cell-cycle arrest biomarkers [TIMP2]*[IGFBP7] have been proposed for early detection of AKI, but their role in critically ill COVID-19 patients is poorly understood.

METHODS

We conducted an observational study to assess the performance of [TIMP2]*[IGFBP7] for the detection of AKI in critical COVID-19 patients admitted to our intensive care unit (ICU). We sampled urinary [TIMP2]*[IGFBP7] levels at ICU admission, 12 h, 24 h, and 48 h, and compared the results to the development of AKI, as well as baseline and laboratory data.

RESULTS

Forty-one patients were enrolled. The median age was 66 years [57-72] and most were males (85%). Thirteen patients (31.7%) developed no/mild stage AKI, 19 patients (46.3%) moderate AKI, and nine patients (22.0%) severe AKI. The ICU mortality was 29.3%. sCr levels in the Emergency Department or at ICU admission were not significantly different according to AKI stage. [TIMP-2]*[IGFBP-7] urinary levels were elevated in severe AKI at 12 h after ICU admission, but not at ICU admission or 24 h or 48 h after ICU admission.

CONCLUSION

Urinary biomarkers [TIMP-2]*[IGFBP-7] were generally increased in this population with a high prevalence of AKI, and were higher in patients with severe AKI measured at 12 h from ICU admission. Further studies are needed to evaluate the best timing of these biomarkers in this population.

Association between dexmedetomidine administration and outcomes in critically ill patients with sepsis-associated acute kidney injury

STUDY OBJECTIVE

To investigate the association between dexmedetomidine administration and outcomes in critically ill patients with sepsis-associated acute kidney injury (SA-AKI).

DESIGN

A single-center, retrospective, cohort study.

SETTING

Intensive care unit (ICU).

PATIENTS

A total of 2192 critically ill patients with SA-AKI were included in the analysis, which identified from the Medical Information Mart for Intensive Care (MIMIC-IV) database between 2008 and 2019.

INTERVENTIONS

Intravenous infusion of dexmedetomidine.

MEASUREMENTS

The primary outcome was recovery of renal function. In-hospital mortality, vasopressor requirements, length of ICU and hospital stay were considered secondary outcomes. The Cox proportional hazards, logistic regression, and linear regression models were used to assess the association between dexmedetomidine and outcomes. Propensity score matching (PSM) analysis was used to match patients receiving dexmedetomidine to those without treatment.

MAIN RESULTS

After PSM, 719 matched patient pairs were derived from patients who received dexmedetomidine and those who did not. The administration of dexmedetomidine was associated with a higher rate of renal recovery [61.8% vs. 55.8%, hazard ratio (HR) 1.35; P = 0.01], reduced in-hospital mortality [28.3% vs. 41.3%, HR 0.56; P < 0.001], and prolonged intensive care unit (ICU) stay [15.8d vs 12.6d, HR 2.34; P < 0.001] and hospital stay [23.7d vs 19.7d, HR 4.47; P < 0.001]. No significant difference was found in vasopressor requirements in patients with SA-AKI. Nevertheless, results illustrated that dose receiving between 0.30 and 1.00 μg/kg/h and duration using under 48 h of dexmedetomidine was associated with improvements in renal function recovery in SA-AKI patients.

CONCLUSION

Dexmedetomidine administration was associated with improvements in renal function recovery and in-hospital survival in critically ill patients with SA-AKI. The results need to be verified in further randomized controlled trials.

Incidence of Acute Kidney Injury in Polytrauma Patients and Predictive Performance of TIMP2 × IGFBP7 Biomarkers for Early Identification of Acute Kidney Injury

Background: Acute kidney injury (AKI) is a common cause of organ failure in trauma patients who survive their initial injuries. It is independently associated with increased morbidity and mortality and prolongs the length of hospital stays. The objectives of this study were to describe the incidence of early AKI and influence of risk factors in polytrauma patients and evaluate the predictive potential of TIMP2 × IGFBP7 biomarkers in this patient cohort. Methods: We conducted a retrospective cohort study of severely injured adult patients who were consecutively admitted to a multidisciplinary ICU from May 2017 to May 2019. Detailed patient data was retrieved from ICU medical records. Fluid balance, urinary output, and sCr values up to 72 h were collected. Urine samples for measuring TIMP2 × IGFBP7 concentrations were obtained and analyzed from ICU admission to 72 h. Results: Among the 153 patients eligible for analysis, 45 were included in the AKI, and 108 in the no AKI cohorts. The incidence of AKI within 72 h, based on KDIGO criteria, was 28.8%. There were no differences in ISS, type and mechanism of injury, heart rate, and systolic BP at admission between groups. Patients with early AKI were older (68 vs. 49 years, p < 0.001), obese (BMI 26.2 vs. 24.7, p < 0.048), and more likely to have previous cardiac disease (27% vs. 5.6%, p < 0.001). TIMP2 × IGFBP7 values on ICU admission were associated with subsequent AKI in patients without evidence of AKI at the time of ICU admission. They were also higher in the AKI cohort and significantly correlated with renal replacement therapy (RRT) and episodes of hypotension. Multivariable analysis confirmed age, previous cardiac disease, and NephroCheck as the variables mostly associated with AKI, with AUC 0.792. Conclusions: TIMP2 × IGFBP7 may help identify trauma patients with tubular damage that may evolve into a clinically manifested syndrome. Prospective studies of TIMP2 × IGFBP7, as a trigger for early AKI bundle care, are warranted.

Prediction model of acute kidney injury after different types of acute aortic dissection based on machine learning

Objective

A clinical prediction model for postoperative combined Acute kidney injury (AKI) in patients with Type A acute aortic dissection (TAAAD) and Type B acute aortic dissection (TBAAD) was constructed by using Machine Learning (ML).

Methods

Baseline data was collected from Acute aortic division (AAD) patients admitted to First Affiliated Hospital of Xinjiang Medical University between January 1, 2019 and December 31, 2021. (1) We identified baseline Serum creatinine (SCR) estimation methods and used them as a basis for diagnosis of AKI. (2) Divide their total datasets randomly into Training set (70%) and Test set (30%), Bootstrap modeling and validation of features using multiple ML methods in the training set, and select models corresponding to the largest Area Under Curve (AUC) for follow-up studies. (3) Screening of the best ML model variables through the model visualization tools Shapley Addictive Explanations (SHAP) and Recursive feature reduction (REF). (4) Finally, the pre-screened prediction models were evaluated using test set data from three aspects: discrimination, Calibration, and clinical benefit.

Results

The final incidence of AKI was 69.4% (120/173) in 173 patients with TAAAD and 28.6% (81/283) in 283 patients with TBAAD. For TAAAD-AKI, the Random Forest (RF) model showed the best prediction performance in the training set (AUC = 0.760, 95% CI:0.630–0.881); while for TBAAD-AKI, the Light Gradient Boosting Machine (LightGBM) model worked best (AUC = 0.734, 95% CI:0.623–0.847). Screening of the characteristic variables revealed that the common predictors among the two final prediction models for postoperative AKI due to AAD were baseline SCR, Blood urea nitrogen (BUN) and Uric acid (UA) at admission, Mechanical ventilation time (MVT). The specific predictors in the TAAAD-AKI model are: White blood cell (WBC), Platelet (PLT) and D dimer at admission, Plasma The specific predictors in the TBAAD-AKI model were N-terminal pro B-type natriuretic peptide (BNP), Serum kalium, Activated partial thromboplastin time (APTT) and Systolic blood pressure (SBP) at admission, Combined renal arteriography in surgery. Finally, we used in terms of Discrimination, the ROC value of the RF model for TAAAD was 0.81 and the ROC value of the LightGBM model for TBAAD was 0.74, both with good accuracy. In terms of calibration, the calibration curve of TAAAD-AKI's RF fits the ideal curve the best and has the lowest and smallest Brier score (0.16). Similarly, the calibration curve of TBAAD-AKI's LightGBM model fits the ideal curve the best and has the smallest Brier score (0.15). In terms of Clinical benefit, the best ML models for both types of AAD have good Net benefit as shown by Decision Curve Analysis (DCA).

Conclusion

We successfully constructed and validated clinical prediction models for the occurrence of AKI after surgery in TAAAD and TBAAD patients using different ML algorithms. The main predictors of the two types of AAD-AKI are somewhat different, and the strategies for early prevention and control of AKI are also different and need more external data for validation.

Macrophage migration inhibitory factor in acute kidneyinjury

Acute kidney injury (AKI) is a complex clinical syndrome with multiple etiologies and pathogenesis, which lacks early biomarkers and targeted therapy. Recently, macrophage migration inhibitory factor (MIF) family protein have received increasing attention owing to its pleiotropic protein molecule character in acute kidney injury, where it performed a dual role in the pathological process. macrophage migration inhibitory factor and macrophage migration inhibitory factor-2 are released into the peripheral circulation when Acute kidney injury occurs and interact with various cellular pathways. On the one hand, macrophage migration inhibitory factor exerts a protective effect in anti-oxidation and macrophage migration inhibitory factor-2 promotes cell proliferation and ameliorates renal fibrosis. On the other hand, macrophage migration inhibitory factor aggravates renal injury as an upstream inflammation factor. Herein, we provide an overview on the biological role and possible mechanisms of macrophage migration inhibitory factor and macrophage migration inhibitory factor-2 in the process of Acute kidney injury and the clinical application prospects of macrophage migration inhibitory factor family proteins as a potential therapeutic target.

Application of Machine Learning for Clinical Subphenotype Identification in Sepsis

INTRODUCTION

Sepsis is a heterogeneous clinical syndrome. Identification of sepsis subphenotypes could lead to allowing more precise therapy. However, there is a lack of models to identify the subphenotypes in such patients. Thus, we aimed to identify possible subphenotypes and compare the clinical outcomes for subphenotypes in a large sepsis cohort.

METHODS

This machine learning-based, cluster analysis was performed using the Medical Information Mart in Intensive Care (MIMIC)-IV database. We enrolled all adult (> 18 years old) patients diagnosed with sepsis in the first 24 h after intensive care unit (ICU) admission. K-means cluster analysis was performed to identify the number of classes. Multivariable logistic regression models were used to estimate the association between sepsis subphenotypes and in-hospital mortality.

RESULTS

A total of 8817 participants with sepsis were enrolled. The median age was 66.8 (IQR, 55.9-77.1) years, and 38.1% (3361/8817) were female. Two subphenotypes resulted in optimal separation including 11 routinely available clinical variables obtained during the first 24 h after ICU admission. Participants in subphenotype B showed higher levels of lactate, glucose and creatinine, white blood cell count, sodium and heart rate and lower body temperature, platelet count, systolic blood pressure, hemoglobin and PaO₂/FiO₂ ratio. In addition, the in-hospital mortality in patients with subphenotype B was significantly higher than that in subphenotype A (29.4% vs. 8.5%, P < 0.001). The difference was still significant after adjustment for potential covariates (adjusted OR 2.214; 95% CI 1.780-2.754, P < 0.001).

CONCLUSIONS

Two sepsis subphenotypes with different clinical outcomes could be rapidly identified using the K-means clustering analysis based on routinely available clinical data. This finding may help clinicians to identify the subphenotype rapidly at the bedside.

Development and Validation of a Prognostic Nomogram to Predict 30-Day Mortality Risk in Patients with Sepsis-Induced Cardiorenal Syndrome

INTRODUCTION

Sepsis-induced cardiorenal syndrome (sepsis-induced CRS) is a devastating medical condition that is frequently associated with a high fatality rate. In this study, we aimed to develop an individualized nomogram that may help clinicians assess 30-day mortality risk in patients diagnosed with sepsis-induced CRS.

METHODS

A total of 340 patients with sepsis-induced CRS admitted from January 2015 to May 2019 in Shanghai Tongji Hospital were used as a training cohort to develop a nomogram prognostic model. The model was constructed using multivariable logistic analyses and was then externally validated by an independent cohort of 103 patients diagnosed with sepsis-induced CRS from June 2019 to December 2020. The prognostic ability of the nomogram was assessed through discrimination, calibration, and accuracy.

RESULTS

Five prognostic factors were determined and included in the nomogram: age, Sequential (sepsis-related) Organ Failure Assessment (SOFA) score, vasopressors, baseline serum creatinine, and the rate of change in myoglobin. Our prognostic nomogram showed well-fitted calibration curves and yielded strong discrimination power with the area under the curve of 0.879 and 0.912 in model development and validation, respectively. In addition, the nomogram prognostic model exhibited an evidently higher predictive accuracy than the SOFA score.

CONCLUSIONS

We developed a prognostic nomogram model for patients with sepsis-induced CRS and externally validated the model in another independent cohort. The nomogram exhibited greater strength in predicting 30-day mortality risk than the SOFA score, which may help clinicians estimate short-term prognosis and modulate therapeutic strategies.

Late-Onset Acute Kidney Injury is a Poor Prognostic Sign for Severe Burn Patients

Background

Acute kidney injury (AKI) is a morbid complication and the main cause of multiple organ failure and death in severely burned patients. The objective of this study was to explore epidemiology, risk factors, and outcomes of AKI for severely burned patients.

Methods

This retrospective study was performed with prospectively collected data of severely burned patients from the Institute of Burn Research in Southwest Hospital during 2011–2017. AKI was diagnosed according to Kidney Disease Improving Global Outcomes (KDIGO) criteria (2012), and it was divided into early and late AKIs depending on its onset time (within the first 3 days or &gt;3 days post burn). The baseline characteristics, clinical data, and outcomes of the three groups (early AKI, late AKI and non-AKI) were compared using logistic regression analysis. Mortality predictors of patients with AKI were assessed.

Results

A total of 637 adult patients were included in analysis. The incidence of AKI was 36.9% (early AKI 29.4%, late AKI 10.0%). Multiple logistic regression analysis revealed that age, gender, total burn surface area (TBSA), full-thickness burns of TBSA, chronic comorbidities (hypertension or/and diabetes), hypovolemic shock of early burn, and tracheotomy were independent risk factors for both early and late AKIs. However, sepsis was only an independent risk factor for late AKI. Decompression escharotomy was a protective factor for both AKIs. The mortality of patients with AKI was 32.3% (early AKI 25.7%, late AKI 56.3%), and that of patients without AKI was 2.5%. AKI was independently associated with obviously increased mortality of severely burned patients [early AKI, OR = 12.98 (6.08–27.72); late AKI, OR = 34.02 (15.69–73.75)]. Compared with patients with early AKI, patients with late AKI had higher 28-day mortality (34.9% vs. 19.4%, p = 0.007), 90-day mortality (57.1% vs. 27.4%, p &lt; 0.0001).

Conclusions

AKI remains prevalent and is associated with high mortality in severely burned patients. Late-onset acute kidney injury had greater severity and worse prognosis.

Nomogram and Machine Learning Models Predict 1-Year Mortality Risk in Patients With Sepsis-Induced Cardiorenal Syndrome

Objective

Early prediction of long-term outcomes in patients with sepsis-induced cardiorenal syndrome (CRS) remains a great challenge in clinical practice. Herein, we aimed to construct a nomogram and machine learning model for predicting the 1-year mortality risk in patients with sepsis-induced CRS.

Methods

This retrospective study enrolled 340 patients diagnosed with sepsis-induced CRS in Shanghai Tongji Hospital between January 2015 and May 2019, as a discovery cohort. Two predictive models, the nomogram and machine learning model, were used to predict 1-year mortality. The prognostic variables used to develop the nomogram were identified based on a forward stepwise binary logistic regression, and the predictive ability of the nomogram was evaluated by the areas under the receiver operating characteristic curve (AUC) and the calibration curve. Meanwhile, machine learning (ML) techniques, such as support vector machine, random forest (RF), and gradient boosted decision tree, were assessed mainly by accuracy and AUC. Feature ranking analysis was performed using the ML algorithm. Both nomogram and ML models were externally validated by an independent cohort of 103 patients diagnosed with sepsis-induced CRS between June 2019 and December 2020.

Results

Age, sequential sepsis-related organ failure score (SOFA), serum myoglobin (MYO), vasopressor use, and mechanical ventilation were identified as independent risk factors for 1-year mortality in the nomogram predictive model. In the discovery cohort, the nomogram yielded higher AUC for predicting mortality than did the SOFA score (0.855 [95% CI: 0.815–0.895] vs. 0.756 [95% CI: 0.705–0.808]). For ML, the model developed by RF showed the highest accuracy (0.765) and AUC (0.854). In feature ranking analysis, factors such as age, MYO, SOFA score, vasopressor use, and baseline serum creatinine were identified as important features affecting 1-year prognosis. Moreover, the nomogram and RF model both performed well in external validation, with an AUC of 0.877 and 0.863, respectively.

Conclusion

Our nomogram and ML models showed that age, SOFA score, serum MYO levels, and the use of vasopressors during hospitalization were the main factors influencing the risk of long-term mortality. Our models may serve as useful tools for assessing long-term prognosis in patients with sepsis-induced CRS.

Could outcomes of intracranial aneurysms be better predict using serum creatinine and glomerular filtration rate?

Purpose:

To analyze the role of serum creatinine levels as a biomarker of intracranial aneurysm outcomes.

Methods:

This is a prospective analysis of outcomes of patients with intracranial aneurysm. One hundred forty-seven patients with serum creatinine at admission and 6 months follow up were included. Linear and logistic regressions were used to analyze the data. Modified Rankin scale (mRS) was used to assess outcome.

Results:

Creatinine level was not directly related to aneurysm outcome nor aneurysm rupture (p > 0.05). However, patients with a glomerular filtration rate (GFR) lower than 72.50 mL·min^–1 had an odds ratio (OR) of 3.049 (p = 0.006) for worse outcome. Similarly, aneurysm rupture had an OR of 2.957 (p = 0.014) for worse outcomes. Stepwise selection model selected 4 variables for outcomes prediction: serum creatinine, sex, hypertension and treatment. Hypertensive patients had, on average, an increase in 0.588 in mRS (p = 0.022), while treatment with microsurgery had a decrease in 0.555 (p = 0.038).

Conclusions:

Patients with higher GFR had better outcomes after 6 months. Patients with higher GFR had better outcomes after 6 months. Creatinine presented an indirect role in GFR values and should be included in models for outcome prediction.

COVID-19-induced acute kidney injury in critically ill patients: epidemiology, risk factors, and outcome

Background

The kidney represents a potential target for severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). Clinical data about acute kidney injury (AKI) during SARS-CoV-2 infection are lacking. We aimed to investigate the proportion, risk factors, and prognosis of AKI in critical patients affected with SARS-CoV-2.

Methods

A case/control study was conducted in two intensive care units of a tertiary teaching hospital.

Results

Among 109 patients, 75 were male (69%) with median age at 64 years and 48 (44%) developed AKI within 4 days (interquartile range [IQR], 1–9). Of them, 11 (23%), 9 (19%), and 28 (58%) were classified as stage 1, 2, and 3, respectively. AKI patients were older and presented more sepsis, acute respiratory distress syndrome, and rhabdomyolysis; higher initial urea and creatinine; more marked inflammatory syndrome and hematological disorders; and required more mechanical ventilation and vasopressors. An elevated D-dimers level (odds ratio [OR], 12.83; 95% confidence interval [CI], 1.9–85) was an independent factor of AKI. Sepsis was near to significance (OR, 5.22; 95% CI, 0.94–28; P=0.058). AKI was independently related to mortality (OR, 6.8; 95% CI, 1.49–105) and significantly reduced the survival (14.7 days; IQR, 12-17 vs. 19.9 days; IQR, 17-22.7; P=0.011) in AKI and no AKI group respectively. Hypoxemia with the ratio of the arterial partial pressure of oxygen and the inspiratory concentration of oxygen <70, and vasopressors were identified as mortality factors.

Conclusions

AKI occurred in almost half the studied patients and significantly worsened their prognosis. A high D-dimers level and sepsis contributed significantly to its development.

Impacts of substituting soybean meal with cold extraction sesame meal on growth accomplishment and health in growing Awassi lambs

Blood metabolites and growing performing were evaluated in lambs (15.7 ± 0.33 kg; initial body weight) fed diets containing either soybean meal or cold extraction sesame meal (SM). The design of the study was a complete randomized design. Twenty-two lambs were divided into two diets, 0% SM (CON) or 12.5% SM (SM12.5) of dietary dry matter (DM), raised for 84 days (7 and 77 days for adaptation and data collection, respectively) and fed ad libitum diets (crude protein (CP) content 15.6% DM). Parameters that were measured included nutrient intake, average daily gain (ADG), digestibility, N balance, and blood parameters. Excluding ether extract (EE) and metabolizable energy intake which were greater (P ≤ 0.05) in the SM12.5 group versus the CON group, no differences in other nutrient intakes were detected (P ≥ 0.05) between the two diets. Lambs fed the SM12.5 diet had more digestibility for DM, CP, neutral detergent fiber, and EE. Nitrogen in feces was lower (P ≤ 0.05) in the SM12.5 group versus the CON group. However, retained N (g/day) increased (P ≤ 0.05) in the SM12.5 group versus the CON group. Final body weight and ADG improved (P ≤ 0.05) in the SM12.5 diet. Cost per kilogram of gain diminished (P ≤ 0.05) in the SM12.5 than the CON diet. Blood glucose increased while creatinine decreased (P ≤ 0.05) in lambs that consumed SM12.5. Results obtained herein proved that replacing soybean meal with sesame meal improved growth performance while reducing the cost of gain in addition to not affecting health negatively.

Role of Urinary Kidney Stress Biomarkers for Early Recognition of Subclinical Acute Kidney Injury in Critically Ill COVID-19 Patients

A high proportion of critically ill patients with COVID-19 develop acute kidney injury (AKI) and die. The early recognition of subclinical AKI could contribute to AKI prevention. Therefore, this study was aimed at exploring the role of the urinary biomarkers NGAL and [TIMP-2] × [IGFBP7] for the early detection of AKI in this population. This prospective, longitudinal cohort study included critically ill COVID-19 patients without AKI at study entry. Urine samples were collected on admission to critical care areas for determination of NGAL and [TIMP-2] × [IGFBP7] concentrations. The demographic information, comorbidities, clinical, and laboratory data were recorded. The study outcomes were the development of AKI and mortality during hospitalization. Of the 51 individuals that were studied, 25 developed AKI during hospitalization (49%). Of those, 12 had persistent AKI (23.5%). The risk factors for AKI were male gender (HR = 7.57, 95% CI: 1.28–44.8; p = 0.026) and [TIMP-2] × [IGFBP7] ≥ 0.2 (ng/mL)2/1000 (HR = 7.23, 95% CI: 0.99–52.4; p = 0.050). Mortality during hospitalization was significantly higher in the group with AKI than in the group without AKI (p = 0.004). Persistent AKI was a risk factor for mortality (HR = 7.42, 95% CI: 1.04–53.04; p = 0.046). AKI was frequent in critically ill COVID-19 patients. The combination of [TIMP-2] × [IGFBP7] together with clinical information, were useful for the identification of subclinical AKI in critically ill COVID-19 patients. The role of additional biomarkers and their possible combinations for detection of AKI in ritically ill COVID-19 patients remains to be explored in large clinical trials.

Real-world Health Data and Precision for the Diagnosis of Acute Kidney Injury, Acute-on-Chronic Kidney Disease, and Chronic Kidney Disease: Observational Study

Background

The criteria for the diagnosis of kidney disease outlined in the Kidney Disease: Improving Global Outcomes guidelines are based on a patient’s current, historical, and baseline data. The diagnosis of acute kidney injury, chronic kidney disease, and acute-on-chronic kidney disease requires previous measurements of creatinine, back-calculation, and the interpretation of several laboratory values over a certain period. Diagnoses may be hindered by unclear definitions of the individual creatinine baseline and rough ranges of normal values that are set without adjusting for age, ethnicity, comorbidities, and treatment. The classification of correct diagnoses and sufficient staging improves coding, data quality, reimbursement, the choice of therapeutic approach, and a patient’s outcome.

Objective

In this study, we aim to apply a data-driven approach to assign diagnoses of acute, chronic, and acute-on-chronic kidney diseases with the help of a complex rule engine.

Methods

Real-time and retrospective data from the hospital’s clinical data warehouse of inpatient and outpatient cases treated between 2014 and 2019 were used. Delta serum creatinine, baseline values, and admission and discharge data were analyzed. A Kidney Disease: Improving Global Outcomes–based SQL algorithm applied specific diagnosis-based International Classification of Diseases (ICD) codes to inpatient stays. Text mining on discharge documentation was also conducted to measure the effects on diagnosis.

Results

We show that this approach yielded an increased number of diagnoses (4491 cases in 2014 vs 11,124 cases of ICD-coded kidney disease and injury in 2019) and higher precision in documentation and coding. The percentage of unspecific ICD N19-coded diagnoses of N19 codes generated dropped from 19.71% (1544/7833) in 2016 to 4.38% (416/9501) in 2019. The percentage of specific ICD N18-coded diagnoses of N19 codes generated increased from 50.1% (3924/7833) in 2016 to 62.04% (5894/9501) in 2019.

Conclusions

Our data-driven method supports the process and reliability of diagnosis and staging and improves the quality of documentation and data. Measuring patient outcomes will be the next step in this project.

Ambiguous definitions for baseline serum creatinine affect acute kidney diagnosis at the emergency department

Background

Acute kidney injury (AKI) incidence is increasing, however AKI is often missed at the emergency department (ED). AKI diagnosis depends on changes in kidney function by comparing a serum creatinine (SCr) measurement to a baseline value. However, it remains unclear to what extent different baseline values may affect AKI diagnosis at ED.

Methods

Routine care data from ED visits between 2012 and 2019 were extracted from the Utrecht Patient Oriented Database. We evaluated baseline definitions with criteria from the RIFLE, AKIN and KDIGO guidelines. We evaluated four baseline SCr definitions (lowest, most recent, mean, median), as well as five different time windows (up to 365 days prior to ED visit) to select a baseline and compared this to the first measured SCr at ED. As an outcome, we assessed AKI prevalence at ED.

Results

We included 47,373 ED visits with both SCr-ED and SCr-BL available. Of these, 46,100 visits had a SCr-BL from the − 365/− 7 days time window. Apart from the lowest value, AKI prevalence remained similar for the other definitions when varying the time window. The lowest value with the − 365/− 7 time window resulted in the highest prevalence (21.4%). Importantly, applying the guidelines with all criteria resulted in major differences in prevalence ranging from 5.9 to 24.0%.

Conclusions

AKI prevalence varies with the use of different baseline definitions in ED patients. Clinicians, as well as researchers and developers of automatic diagnostic tools should take these considerations into account when aiming to diagnose AKI in clinical and research settings.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12882-021-02581-x.

Neutrophil-to-lymphocyte ratio is a marker for acute kidney injury progression and mortality in critically ill populations: a population-based, multi-institutional study

Backgrounds

Neutrophil-to-lymphocyte ratio (NLR), a surrogate marker of systemic response to physiological stress, is used for prognosis prediction in many diseases. However, the usefulness of this marker for predicting acute kidney injury (AKI) progression is unclear.

Methods

This retrospective study was based on the Chang Gung Research Database. Patients admitted to the intensive care unit with a diagnosis of stage 1 or 2 AKI were identified. The primary outcome was a composite of progression to stage 3 AKI, requirement of renal replacement therapy, or 14-day in-hospital mortality. The association between NLR and the primary outcome was examined using a logistic regression model and multivariable analysis. The nonlinearity and cutoff points of this relationship were determined using a restricted cubic spline model.

Results

A total of 10,441 patients were enrolled. NLR level at the time of stage 1–2 AKI diagnosis was a marker of adverse outcomes. After adjustment for confounders, NLR was independently associated with the composite outcome of AKI progression, renal replacement therapy, or mortality. The restricted cubic spline model revealed a J-shaped curve, with the lowest odds ratio for an NLR between 7 and 38. Subgroup analysis revealed linear and J-shaped relationships between NLR and the primary outcome in patients admitted to the intensive care unit for medical reasons and for cardiovascular surgery, respectively.

Conclusions

NLR is an independent marker of AKI progression and in-hospital mortality. Because it is readily available in daily practice, it might be used for risk stratification in the AKI population.

Graphic abstract

Supplementary Information

The online version contains supplementary material available at 10.1007/s40620-021-01162-3.

A Prediction Model for Assessing Prognosis in Critically Ill Patients with Sepsis-associated Acute Kidney Injury

BACKGROUND

Sepsis-associated acute kidney injury (SA-AKI) is a common problem in critically ill patients and is associated with high morbidity and mortality. Early prediction of the survival of hospitalized patients with SA-AKI is necessary, but a reliable and valid prediction model is still lacking.

METHODS

We conducted a retrospective cohort analysis based on a training cohort of 2,066 patients enrolled from the Multiparameter Intelligent Monitoring in Intensive Care Database III (MIMIC III) and a validation cohort of 102 patients treated at Nanfang Hospital of Southern Medical University. Least absolute shrinkage and selection operator (LASSO) regression and multivariate Cox regression analysis were used to identify predictors for survival. Areas under the ROC curves (AUC), the concordance index (C-index), and calibration curves were used to evaluate the efficiency of the prediction model (SAKI) in both cohorts.

RESULTS

The overall mortality of SA-AKI was approximately 18%. Age, admission type, liver disease, metastatic cancer, lactate, BUN/SCr, admission creatinine, positive culture, and AKI stage were independently associated with survival and combined in the SAKI model. The C-index in the training and validation cohorts was 0.73 and 0.72. The AUC in the training cohort was 0.77, 0.72, and 0.70 for the 7-day, 14-day, and 28-day probability of in-hospital survival, respectively, while in the external validation cohort, it was 0.83, 0.73, and 0.67. SAPSII and SOFA scores showed poorer performance. Calibration curves demonstrated a good consistency.

CONCLUSIONS

Our SAKI model has predictive value for in-hospital mortality of SA-AKI in critically ill patients and outperforms generic scores.

Elevated serum galectin-1 concentrations are associated with increased risks of mortality and acute kidney injury in critically ill patients

BACKGROUND

Galectin-1 (Gal-1), a member of the β-galactoside binding protein family, is associated with inflammation and chronic kidney disease. However, the effect of Gal-1 on mortality and acute kidney injury (AKI) in critically-ill patients remain unclear.

METHODS

From May 2018 to March 2020, 350 patients admitted to the medical intensive care unit (ICU) of Taipei Veterans General Hospital, a tertiary medical center, were enrolled in this study. Forty-one patients receiving long-term renal replacement therapy were excluded. Serum Gal-1 levels were determined within 24 h of ICU admission. The patients were divided into tertiles according to their serum Gal-1 levels (low, serum Gal-1 < 39 ng/ml; median, 39-70 ng/ml; high, ≥71 ng/ml). All patients were followed for 90 days or until death.

RESULTS

Mortality in the ICU and at 90 days was greater among patients with elevated serum Gal-1 levels. In analyses adjusted for the body mass index, malignancy, sepsis, Sequential Organ Failure Assessment (SOFA) score, and serum lactate level, the serum Gal-1 level remained an independent predictor of 90-day mortality [median vs. low: adjusted hazard ratio (aHR) 2.11, 95% confidence interval (CI) 1.24-3.60, p = 0.006; high vs. low: aHR 3.21, 95% CI 1.90-5.42, p < 0.001]. Higher serum Gal-1 levels were also associated with a higher incidence of AKI within 48 h after ICU admission, independent of the SOFA score and renal function (median vs. low: aHR 2.77, 95% CI 1.21-6.34, p = 0.016; high vs. low: aHR 2.88, 95% CI 1.20-6.88, p = 0.017). The results were consistent among different subgroups with high and low Gal-1 levels.

CONCLUSION

Serum Gal-1 elevation at the time of ICU admission were associated with an increased risk of mortality at 90 days, and an increased incidence of AKI within 48 h after ICU admission.

Dynamic monitoring of kidney injury status over 3 days in the intensive care unit as a sepsis phenotype associated with hospital mortality and hyperinflammation

Background

Sepsis-associated acute kidney injury (AKI) often worsens with the deterioration of a patient's condition. Therefore, we hypothesized that monitoring AKI dynamically from day 1 to day 3 was potential to predict hospital mortality. Specifically, we explored whether monitoring AKI dynamically in the intensive care unit (ICU) could be a sepsis phenotype predictive of mortality. A new classification was established based on the change in the AKI stage from admission day 1 and day 3. We compared the hospital mortality, cytokines, and immune response pattern between each group.

Methods

We retrospectively enrolled 523 patients with sepsis, and we calculated the AKI stages on day 1 and day 3 admission to ICUs.

Among these 523 people, 388 of them were assigned to normal, improved, and deteriorated groups according to the changes in the AKI stages. 263 of which did not develop AKI on day 1 and day 3 (normal group). The AKI stage improved in 68 patients (improved group) and worsened in 57 (deteriorated group). We compared the mortality rates between the groups, and identified the relationship between the dynamic AKI status, immune response patterns, and cytokine levels.

Results

The hospital mortality rate in the deteriorated group was higher than that in the non-deteriorated group (combination of normal and improved group) (p = 0.004). Additionally, according to the Kaplan–Meier analysis, the non-deteriorated group had a distinct hospital survival curve (p = 0.004). Furthermore, both the overexpression of tumor necrosis factor-α and decreased monocyte expression of human leukocyte antigen-DR were present in the deteriorated group.

Conclusions

The deteriorated group was associated with a higher hospital mortality rate, potentially resulting from an abnormal inflammatory response. Worsening AKI in the first 3 days of ICU admission may be a sepsis phenotype predictive of hospital mortality.

Admission creatinine is associated with poor outcomes in burn patients

INTRODUCTION

Renal failure is the most common organ failure in severely burned patients. However, defining acute kidney injury and renal failure is very challenging. This study was designed to determine the relationship between a biomarker commonly measured on admission, serum creatinine, and outcomes in burn patients.

METHODS

We conducted a retrospective cohort study of adult patients (≥ 18 years) with a burn ≥ 5% total body surface area (TBSA) and a serum creatinine level measured within the first 72 h after injury. Patients were admitted over an 11-year period and divided into two groups based on creatinine levels measured within the first 72 h after injury. Patients were categorized in the high creatinine group if they had a measured creatinine ≥107 μmol/L (≥1.21 mg/dL); this value was chosen as the threshold for creatinine based on our institution's reference range. Clinical outcomes included morbidities, hospital length of stay, and mortality. Multivariable logistic regression was used to model the association between high admission creatinine and each outcome, adjusting for patient and injury characteristics.

RESULTS

We studied 923 patients, mean age 47 ± 18 years and median 13% (IQR 8-24) TBSA burned. There were 718 patients categorized with low admission creatinine and 205 patients with high admission creatinine. After adjustment for patient and injury characteristics, high admission creatinine was associated with a significantly higher rate of sepsis (OR 3.44; 95% CI 2.11-5.59), pneumonia (OR 4.56; 95% CI 1.8-11.53), and mortality (OR 3.59; 95% CI 1.91-6.75).

CONCLUSIONS

Elevated creatinine on admission is associated with an increased risk of morbidity and mortality. We suggest that admission creatinine can be used as a "red flag" to identify patients at a higher risk for poor outcomes.

Malaria-Associated Acute Kidney Injury in African Children: Prevalence, Pathophysiology, Impact, and Management Challenges

Acute kidney injury (AKI) is emerging as a complication of increasing clinical importance associated with substantial morbidity and mortality in African children with severe malaria. Using the Kidney Disease: Improving Global Outcomes (KDIGO) criteria to define AKI, an estimated 24–59% of African children with severe malaria have AKI with most AKI community-acquired. AKI is a risk factor for mortality in pediatric severe malaria with a stepwise increase in mortality across AKI stages. AKI is also a risk factor for post-discharge mortality and is associated with increased long-term risk of neurocognitive impairment and behavioral problems in survivors. Following injury, the kidney undergoes a process of recovery and repair. AKI is an established risk factor for chronic kidney disease and hypertension in survivors and is associated with an increased risk of chronic kidney disease in severe malaria survivors. The magnitude of the risk and contribution of malaria-associated AKI to chronic kidney disease in malaria-endemic areas remains undetermined. Pathways associated with AKI pathogenesis in the context of pediatric severe malaria are not well understood, but there is emerging evidence that immune activation, endothelial dysfunction, and hemolysis-mediated oxidative stress all directly contribute to kidney injury. In this review, we outline the KDIGO bundle of care and highlight how this could be applied in the context of severe malaria to improve kidney perfusion, reduce AKI progression, and improve survival. With increased recognition that AKI in severe malaria is associated with substantial post-discharge morbidity and long-term risk of chronic kidney disease, there is a need to increase AKI recognition through enhanced access to creatinine-based and next-generation biomarker diagnostics. Long-term studies to assess severe malaria-associated AKI’s impact on long-term health in malaria-endemic areas are urgently needed.

Relationship between acute kidney injury and mortality in poisoning - a systematic review and metanalysis

RATIONALE

Three consensus classifications of acute kidney injury have been published. These are RIFLE (Risk, Injury, Failure, Loss of kidney function, and End-stage kidney disease published by the Acute Dialysis Quality Initiative workgroup), AKIN (published by the Acute Kidney Injury Network) and KDIGO (published by the Kidney Disease Improving Global Outcome workgroup). Acute kidney injury has been reported consistently as associated with worsened outcomes. However, toxicant-related acute kidney injury has been excluded from the studies used to validate the classifications of acute kidney injury.

OBJECTIVE

To study whether poisoned patients who develop acute kidney injury, as defined by consensus definitions/classifications, have higher mortality compared to those who did not.

METHODS

Databases were searched from 2004 to 2019 using the following keywords (KDIGO OR "Kidney Disease: Improving Global Outcomes" OR "Kidney Disease Improving Global Outcomes" OR AKIN OR "AKI network" OR "Acute kidney Injury Network" OR ADQI OR RIFLE OR "Acute dialysis quality initiative") AND (intoxication OR poisoning OR overdose OR ingestion) AND (AKI OR kidney OR renal OR ARF). If data were available, we used a random-effects meta-analysis model and Fisher's exact test to compare mortality in patients according to kidney function definitions (acute kidney injury vs not) and stages (stages vs no acute kidney injury), respectively. If data were available, we assessed the correlation between mortality and renal function (no acute kidney injury, risk/stage 1, injury/stage 2 and failure/stage 3) using the Spearman correlation. If available, we collected the results of statistical analyses in studies that have used acute kidney injury to predict mortality.

RESULTS

Study selection. Thirty-three relevant studies were found, 22/33 retrospective studies (67%) and 11/33 prospective studies (33%). Paraquat was the most frequent toxicant involved (13/33, 39%). We found a disparity between studies regarding the timeframe during which mortality was assessed, the temporality of the renal function considered to predict mortality (initial/worst) and the criteria used to define/grade acute kidney injury across studies. Univariate association between acute kidney injury definitions/stages and mortality. Consensus definitions/staging of acute kidney injury were associated with higher mortality, using univariate analyses, in twenty-eight (RIFLE = 7; AKIN = 12; KDIGO = 9) studies included but not in five (AKIN = 4, KDIGO = 1). When available data were pooled, RIFLE (5 studies), AKIN (16 studies) and KDIGO definitions (8 studies) of acute kidney injury were associated with a higher mortality (Log unadjusted Odds ratios [95%-confidence interval], 2.60 [2.23; 2.97], 2.02 [1.48; 2,52] and 3.22 [2,65; 3.78], respectively). However, we found high heterogeneity (I²=54,7%) and publication bias among studies using AKIN. In ten studies with available data, the correlation between renal function (no acute kidney injury, risk/stage 1, injury/stage 2, failure/stage 3) and mortality was significant in 5 studies (RIFLE = 2; AKIN = 3), but not in five studies (RIFLE = 1; AKIN = 3; KDIGO = 1).Multivariate association between acute kidney injury definitions/stages and mortality. The definitions of acute kidney injury were associated with higher mortality in two studies (RIFLE = 2), but not in four studies (AKIN = 1 and KDIGO = 3. The stages of acute kidney injury (including one or more stages) were associated with higher mortality in four (RIFLE = 1, AKIN = 1 and KDIGO = 2).

CONCLUSIONS

All three consensus definitions/classifications were associated independently with increased mortality in poisoning but with disparity between studies reporting acute kidney injury.

Perioperative use of serum creatinine and postoperative acute kidney injury: a single-centre, observational retrospective study to explore physicians' perception and practice

BACKGROUND

Postoperative acute kidney injury (PO-AKI) is a leading cause of short- and long-term morbidity and mortality, as well as progression to chronic kidney disease (CKD). The aim of this study was to explore the physicians' attitude toward the use of perioperative serum creatinine (sCr) for the identification of patients at risk for PO-AKI and long-term CKD. We also evaluated the incidence and risk factors associated with PO-AKI and renal function deterioration in patients undergoing major surgery for malignant disease.

METHODS

Adult oncological patients who underwent major abdominal surgery from November 2016 to February 2017 were considered for this single-centre, observational retrospective study. Routinely available sCr values were used to define AKI in the first three postoperative days. Long-term kidney dysfunction (LT-KDys) was defined as a reduction in the estimated glomerular filtration rate by more than 10 ml/min/m² at 12 months postoperatively. A questionnaire was administered to 125 physicians caring for the enrolled patients to collect information on local attitudes regarding the use of sCr perioperatively and its relationship with PO-AKI.

RESULTS

A total of 423 patients were observed. sCr was not available in 59 patients (13.9%); the remaining 364 (86.1%) had at least one sCr value measured to allow for detection of postoperative kidney impairment. Among these, PO-AKI was diagnosed in 8.2% of cases. Of the 334 patients who had a sCr result available at 12-month follow-up, 56 (16.8%) developed LT-KDys. Data on long-term kidney function were not available for 21% of patients. Interestingly, 33 of 423 patients (7.8%) did not have a sCr result available in the immediate postoperative period or long term. All the physicians who participated in the survey (83 out of 125) recognised that postoperative assessment of sCr is required after major oncological abdominal surgery, particularly in those patients at high risk for PO-AKI and LT-KDys.

CONCLUSION

PO-AKI after major surgery for malignant disease is common, but clinical practice of measuring sCr is variable. As a result, the exact incidence of PO-AKI and long-term renal prognosis are unclear, including in high-risk patients.

TRIAL REGISTRATION

ClinicalTrials.gov , NCT04341974 .

Prevalence and impact on outcome of sodium and potassium disorders in patients with community-acquired pneumonia: A retrospective analysis

INTRODUCTION

Disorders of sodium and potassium are common and predictors of adverse outcome. Prevalence and impact on outcome of hypokalemia, hyperkalemia, hyponatremia and hypernatremia were investigated in emergency patients with community-acquired pneumonia (CAP).

METHODS

Patients ≥18 years presenting to our emergency department between January 1st 2017 and December 31st 2018 with on-admission electrolyte measurements were included. Chart reviews were performed to identify patients with CAP.

RESULTS

19.948 cases had measurements of sodium and potassium of which 469 had CAP (2.4%). Prevalence of hypo- and hypernatremia was significantly increased in patients with compared to those without CAP (hyponatremia: 28.8% vs. 10.5% respectively, p<0.0001; hypernatremia: 1.9% vs. 0.6% respectively, p=0.002). The prevalence of hypo- and hyperkalemia was significantly higher in patients with than without CAP (hypokalemia 15.6% vs. 11.4% respectively, p=0.004; hyperkalemia: 4.5% vs. 2.0% respectively, p=0.001). Hyponatremia was significantly associated with longer hospital stay in patients with CAP (regression coefficient 0.194, standard error 0.079, p=0.015). None of the investigated electrolyte disorders were predictive of 30-day re-admission and 180-day pneumonia recurrence rates. Use of loop diuretics was an independent predictor for 30-day re-admission (OR 2.351 (1.099-5.03). p=0.028). Pneumonia Severity Index (PSI) risk class was an independent predictor of 180-day pneumonia recurrence (OR 1.494 (1.022-2.184), p=0.038).

CONCLUSION

Dysnatremias and dyskalemias are common findings complicating CAP in emergency patients. Prevalence of hyponatremia was highest followed by hypokalemia. Hyponatremia was an independent predictor of prolonged length of hospital stay. Loop diuretic use was associated with 30-day readmission and PSI risk class with 180-day pneumonia recurrence.

[Acute kidney injury in patients hospitalized with COVID-19 in Wuhan, China: a single-center retrospective observational study]

OBJECTIVE

To assess the predictors and outcomes of acute kidney injury (AKI) among patients with coronavirus disease 2019 (COVID-19).

OBJECTIVE

This retrospective observational study was conducted among patients with a confirmed diagnosis of COVID-19 admitted to Hankou Hospital between January, 5 and March 8, 2020. We evaluated the association of AKI with the demographic and biochemical parameters and clinical outcomes of the patients using univariate regression analysis.

OBJECTIVE

Atotal of 287 COVID-19 patients, including 55 with AKI and 232 without AKI, were included in the analysis. Compared with the patients without AKI, the patients with AKI were older, predominantly male, and were more likely to have hypoxia and pre-existing hypertension and cerebrovascular diseases. The patients with AKI also had higher levels of white blood cells, D-dimer, aspartate aminotransferase, total bilirubin, creatine kinase, lactate dehydrogenase, procalcitonin, C-reactive protein, a higher prevalence of hyperkalemia, lower lymphocyte counts, and higher chest computed tomographic scores. The incidence of stage 1 AKI was 14.3% and that of stage 2 or 3 AKI was 4.9%. The patients with AKI had much higher mortality rate than those without AKI.

OBJECTIVE

AKI is an important complication of COVID-19. An older age, a male gender, multiple pre- existing comorbidities, lymphopenia, increased infection indicators, elevated D-dimer, and impaired heart and liver functions are all potential risk factors ofAKI. COVID- 19 patients with AKI that progresses into stages 2 or 3 AKI have a high mortality rate. Prevention of AKI and monitoring kidney function is critical in the care of COVID-19 patients.

Acute kidney injury in patients with severe COVID-19 in Mexico

Introduction

Some patients with COVID-19 pneumonia present systemic disease involving multiple systems. There is limited information about the clinical characteristics and events leading to acute kidney injury (AKI). We described the factors associated with the development of AKI and explored the relation of AKI and mortality in Mexican population with severe COVID-19.

Methods

We retrospectively reviewed the medical records of individuals with severe pneumonia caused by SARS-CoV-2 hospitalized at the largest third-level reference institution for COVID-19 care in Mexico between March and April 2020. Demographic information, comorbidities, clinical and laboratory data, dates of invasive mechanical ventilation (IMV) and hospitalization, mechanical-ventilator settings and use of vasoactive drugs were recorded.

Results

Of 99 patients studied, 58 developed AKI (58.6%). The risk factors for AKI were older age (OR = 1.07, 95% CI = 1.01–1.13, p = 0.024); obesity (OR = 6.58, 95% CI = 1.8–24.05, p = 0.040); and the need for IMV (OR = 6.18, CI = 1.29–29.58, p = 0.023). The risk factors for mortality were obesity (OR = 5.57, 95% CI = 1.48–20.93, p = 0.011); requirement of vasoactive drugs on admission (OR = 5.35, 95% CI = 1.16–24.61, p = 0.031); and AKI (OR = 8.61, 95% CI = 2.24–33.1, p = 0.002). In-hospital mortality was significantly higher in patients with AKI stage 3 (79.3%) and AKI stage 2 (68.7%) compared with those with AKI stage 1 (25%; p = 0.004). Fifty-three patients underwent the furosemide stress test (FST) to predict progression to AKI stage 3. Of those, 12 progressed to AKI stage 3 (22%). The ROC curve for the FST had an AUC of 0.681 (p = 0.009); a sensitivity of 81.6% and a specificity of 54.5%.

Conclusions

AKI was common in our cohort of patients with severe pneumonia caused by SARS-CoV-2 infection. The risk factors for AKI were older age, obesity and the need for of IMV on admission. The risk factors for mortality were obesity, requirement of vasoactive drugs on admission and AKI. Mortality was more frequent in patients with AKI stages 2–3. The FST had an acceptable predictive capacity to identify patients progressing to AKI stage 3.

Modification of Pediatric Sequential Organ Failure Assessment Score Using Acute Kidney Injury Diagnostic Criteria

OBJECTIVES

To develop a modified pediatric Sequential Organ Failure Assessment score using the acute kidney injury diagnostic criteria and evaluate its performance in predicting mortality.

DESIGN

A single-center retrospective study.

SETTING

Fourteen-bed PICU in a tertiary care academic children's hospital.

PATIENTS

Critically ill children admitted to the PICU between January 2017 and September 2019 with at least more than two serum creatinine measurements-one for baseline and the other within the first 48 hours of PICU admission.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

A total of 755 patients were included. Overall, 265 patients were diagnosed with acute kidney injury using the current acute kidney injury diagnostic criteria. The overall PICU mortality was 5.8%. Patients with acute kidney injury required more vasoactive-inotropic drugs and showed higher illness severity scores, including the Pediatric Risk of Mortality III, Pediatric Logistic Organ Dysfunction 2, pediatric Sequential Organ Failure Assessment, and modified pediatric Sequential Organ Failure Assessment scores, as well as higher PICU mortality than patients without acute kidney injury (p < 0.001). As acute kidney injury stages increase, PICU mortality also increased (p < 0.001). Based on multivariable logistic regression analysis adjusted for age and sex, the modified pediatric Sequential Organ Failure Assessment score was an independent prognostic factor of PICU mortality. The modified pediatric Sequential Organ Failure Assessment score showed better performance in predicting PICU mortality (area under the receiver operating characteristic curve, 0.821; 95% CI, 0.759-0.882) than other severity scores (area under the receiver operating characteristic curve [95% CI] of Pediatric Risk of Mortality III, Pediatric Logistic Organ Dysfunction 2, and pediatric Sequential Organ Failure Assessment scores: 0.788 [0.723-0.853], 0.735 [0.663-0.807], and 0.785 [0.718-0.853], respectively).

CONCLUSIONS

Acute kidney injury is prevalent and associated with poor clinical outcomes in critically ill children. The modified pediatric Sequential Organ Failure Assessment score, based on the acute kidney injury diagnostic criteria, showed improved performance in predicting PICU mortality. The modified pediatric Sequential Organ Failure Assessment score could be a promising prognostic factor for critically ill children.

Dyskalemias in patients with acute kidney injury presenting to the emergency department are common and independent predictors of adverse outcome

BACKGROUND

No data concerning the prevalence and risk factors of dyskalemia in acute kidney injury (AKI) exist. We investigated (a) prevalence rates, (b) risk factors and (c) outcome of hypo- and hyperkalemia in emergency patients.

METHODS

In this cross-sectional analysis, all patients admitted to the emergency department of a large public hospital in Switzerland between January 1st 2017 and December 31st 2018 with measurements of creatinine and potassium were included. Baseline characteristics, medication and laboratory data were extracted. Chart reviews were performed to identify patients with a diagnosis of chronic kidney disease (CKD) and to extract their baseline creatinine. For all other patients, the ADQI backformula was used in order to calculate baseline creatinine. AKI was graduated using creatinine criteria of the acute kidney injury network. Binary logistic regression analysis was used to identify risk factors for appearance of hyperkalemia and outcome.

RESULTS

AKI was found in 8% of patients. Hyperkalemia was present in 13% and hypokalemia in 11% of patients with AKI. AKI stage, potassium-sparing diuretics, ACE inhibitors and underlying CKD were the strongest risk factors for hyperkalemia. Hyperkalemia as well as profound hypokalemia were independently associated with prolonged length of stay and in-hospital mortality. The study is limited by its dependency on chart review data in order to identify patients with chronic kidney disease and by limitations of the ADQI backformula to calculate baseline creatinine.

CONCLUSIONS

Dyskalemias are common in emergency patients with AKI and are independent risk factors for adverse outcomes. Potassium-sparing diuretics, ACE-inhibitors, AKIN stage and CKD are predictors of hyperkalemia in AKI.

Combination of biomarker with clinical risk factors for prediction of severe acute kidney injury in critically ill patients

Background

Acute kidney injury (AKI) occurs commonly in the intensive care unit (ICU). Insulin-like growth factor-binding protein 7 (IGFBP7) and tissue inhibitor of metalloproteinase-2 (TIMP-2), known as [TIMP-2] x [IGFBP7] (NephroCheck), have been identified as novel biomarkers for the prediction of AKI risk. However, the effective use of disease biomarkers is indispensable from an appropriate clinical context. We conducted a retrospective cohort study to find risk factors and assess the performance of the combination of NephroCheck with risk factors, so as to provide feasible information for AKI prediction.

Methods

All patients who were admitted in the ICU (from June 2016 to July 2017) participated in the study. The primary outcome was the detection of severe AKI within the first 7 days after patients being admitted to the ICU. The predictors were separated into three categories: chronic risk factors, acute risk factors and biochemical indicators.

Results

The study included 577 patients. 96 patients developed to severe AKI (16.6%) within 7 days. In addition to NephroCheck (+) (OR = 2.139, 95% CI (1.260–3.630), P = 0.005), age > 65 years (OR = 1.961, 95% CI (1.153–3.336), P = 0.013), CKD (OR = 2.573, 95% CI (1.319–5.018), P = 0.006) and PCT (+)(OR = 3.223, 95% CI (1.643–6.321), P = 0.001) were also the independent predictors of severe AKI within 7 days. Compared to NephroCheck (+) only (AUC = 0.66, 95% CI:0.60–0.72), the combination of NephroCheck (+) and risk factors (age > 65 years, CKD and PCT positive) (AUC = 0.75, 95% CI:0.70–0.81) led to a significant increase in the area under ROC curve for severe AKI prediction within 7 days.

Conclusions

Although NephroCheck is an effective screening tool for recognizing high-risk patients, we found that combination with biomarker and risk factors (age > 65 years, CKD, procalcitonin positive) for risk assessment of AKI has the greatest significance to patients with uncertain disease trajectories.

Prognostic value of dynamic plasma endostatin for the prediction of mortality in acute kidney injury: A prospective cohort study

Objective

The aim of the current study was to evaluate the value of plasma endostatin for predicting 30-day mortality of patients with acute kidney injury (AKI).

Methods

Patients who underwent non-cardiac major surgery and developed AKI in the first 48 hours after admission to the intensive care unit were consecutively included. Concentrations of plasma neutrophil gelatinase-associated lipocalin (NGAL), cystatin C (Cys C), and endostatin were measured at three time points: 0, 24, and 48 hours after the AKI diagnosis. Clinical patient characteristics were recorded after AKI was diagnosed.

Results

A total of 256 new-onset AKI patients were enrolled. Of these, 48 (18.7%) patients died within 30 days. The difference in plasma endostatin values between 0 and 24 hours (ΔEndostatin-24h) yielded the best area under the curve (AUC) of 0.747 for predicting 30-day mortality in AKI patients; NGAL and Cys C achieved AUC of 0.672 and 0.647, respectively. The predictive AUC increased to 0.833 when ΔEndostatin-24h was combined with sequential organ failure assessment score and AKI classification.

Conclusion

Dynamic plasma endostatin is useful for predicting 30-day mortality in AKI patients. The predictive power of dynamic plasma endostatin can be significantly improved when it is combined with clinical patient data.

Tubular injury and cell-cycle arrest biomarkers to predict acute kidney injury in noncritically ill children receiving aminoglycosides

Aim: NGAL, IL-18, KIM-1 as well as urinary TIMP2 and IGFBP7 and their mathematical product (TIMP2*IGFBP7) were evaluated for detecting pediatric aminoglycoside acute kidney injury (AG-AKI). Methods: In a prospective study, noncritically ill children received aminoglycosides (AG) ≥3 days. The area under the curve (AUC) for biomarkers to detect AKI was calculated by a) days before AKI onset; b) treatment days. Results: There were 113 AG episodes (68% febrile neutropenia). The AKI group had a higher proportion with febrile neutropenia. The AKI group had significantly lower NGAL 3 days before AKI, as patients with febrile neutropenia had a lower NGAL during AG treatment (p < 0.05). NGAL, IL-18 and TIMP2*IGFBP7 had AUC ≥0.73 at 3, 2 and 2 days before AKI onset. Conclusion: NGAL, IL-18 and TIMP2*IGFBP7 were modest early biomarkers of AG-AKI. Febrile neutropenia was associated with lower NGAL.

Point-of-care creatinine measurements to predict acute kidney injury

BACKGROUND

Plasma creatinine (Cr) is a marker of kidney function and typically measured once daily. We hypothesized that Cr measured by point-of-care technology early after ICU admission would be a good predictor of acute kidney injury (AKI) the next day in critically ill patients.

METHODS

We conducted a retrospective database audit in a single tertiary ICU database. We included patients with normal first admission Cr (Cr_F ) and identified a Cr value (Cr_P ) obtained within 6-12 hours from ICU admission. We used their difference converted into percentage (delta-Cr-%) to predict subsequent AKI (based on Cr and/or need for renal replacement therapy) the next day. We assessed predictive value by calculating area under the receiver characteristic curve (AUC), logistic regression models for AKI with and without delta-Cr-%, and the category-free net reclassifying index (cfNRI).

RESULTS

We studied 780 patients. Overall, 70 (9.0%) fulfilled the Cr AKI definition by Cr_P measurement. On day 2, 148 patients (19.0%) were diagnosed with AKI. AUC (95% CI) for delta-Cr-% to predict AKI on day 2 was 0.82 (95% CI 0.78-0.86), and 0.74 (95% CI 0.69-0.80) when patients with AKI based on the Cr_P were excluded. Using a cut-off of 17% increment, the positive likelihood ratio (95% CI) for delta-Cr-% to predict AKI was 3.5 (2.9-4.2). The cfNRI was 90.0 (74.9-106.1).

CONCLUSIONS

Among patients admitted with normal Cr, early changes in Cr help predict AKI the following day.