Timing of Renal-Replacement Therapy in Patients with Acute Kidney Injury and Sepsis

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

BACKGROUND

Acute kidney injury (AKI) is a common complication of critical illness and associated with high morbidity and mortality. Optimal timing of continuous kidney replacement therapy (CKRT) in children is unknown. We aimed to measure the association between timing of initiation and mortality.

METHODS

This is a single-center retrospective cohort study of pediatric patients receiving CKRT from 2013 to 2019. The primary exposure, time to CKRT initiation, was measured from onset of stage 3 AKI during hospitalization (defined using Kidney Disease: Improving Global Outcomes creatinine and urine output criteria) and analyzed as both a continuous and categorical variable. The primary outcome was ICU mortality.

RESULTS

Ninety-nine patients met criteria for analysis. Overall mortality was 39% (39/99). Median time from stage 3 AKI onset to CKRT initiation was 1.5 days in survivors and 5.5 days in nonsurvivors (p < 0.001). In multivariable analysis, increased time to CKRT initiation was independently associated with mortality [OR 1.02 per hour (95% CI 1.01-1.04), p < 0.001]. Longer time to CKRT initiation was associated with higher odds of mortality in ascending time intervals. Patients started on CKRT > 2 days compared to < 2 days after stage 3 AKI onset had higher mortality (65% vs. 5%, p < 0.001), longer median ICU length of stay (25 vs. 12 d, p < 0.001), longer median CKRT duration (11 vs. 5 d, p < 0.001), and fewer AKI-free days (0 vs. 14 d, p < 0.001).

CONCLUSIONS

Longer time to initiation of CKRT after development of severe AKI is independently associated with mortality. Consideration of early CKRT in this high-risk population may be a strategy to reduce mortality and improve recovery of kidney function. However, there remains significant heterogeneity in the definition of early versus late initiation and the optimal timing of CKRT remains unknown.

Acute Kidney Injury and Subsequent Cardiovascular Disease: Epidemiology, Pathophysiology, and Treatment

Cardiovascular disease poses a significant threat to individuals with kidney disease, including those affected by acute kidney injury (AKI). In the short term, AKI has several physiological consequences that can impact the cardiovascular system. These include fluid and sodium overload, activation of the renin-angiotensin-aldosterone system and sympathetic nervous system, and inflammation along with metabolic complications of AKI (acidosis, electrolyte imbalance, buildup of uremic toxins). Recent studies highlight the role of AKI in elevating long-term risks of hypertension, thromboembolism, stroke, and major adverse cardiovascular events, though some of this increased risk may be due to the impact of AKI on the course of chronic kidney disease. Current management strategies involve avoiding nephrotoxic agents, optimizing hemodynamics and fluid balance, and considering renin-angiotensin-aldosterone system inhibition or sodium-glucose cotransporter 2 inhibitors. However, future research is imperative to advance preventive and therapeutic strategies for cardiovascular complications in AKI. This review explores the existing knowledge on the cardiovascular consequences of AKI, delving into epidemiology, pathophysiology, and treatment of various cardiovascular complications following AKI.

Positive pathogens in stool could predict the clinical outcomes of sepsis-associated acute kidney injury in critical ill patient

In this study, we sought to evaluate the influence of positive pathogens in stool (PPS) on clinical outcomes in critical ill patients with Sepsis-associated acute kidney injury (S-AKI) from intensive care unit. Our sample consisted of 7338 patients, of whom 752 (10.25%) had PPS. We found that the presence of Clostridium difficile (C. difficile) and protists in stool samples was correlated with survival during hospitalization, as well as 30-day and 90-day survival. Interestingly, there was no significant difference in overall survival and 30-day in-hospital survival between the PPS group and the negative pathogens in stool (NPS) control group. However, the cumulative incidence of 90-day infection-related mortality was significantly higher in the PPS group (53 vs. 48%, P = 0.022), particularly in patients with C. difficile in their stool specimens. After adjusting for propensity scores, the results also have statistical significance. These findings suggest that PPS may affect the 90-days survival outcomes of S-AKI, particularly in patients with C. difficile and protists in their stool samples. Further research is warranted to further explore these associations.

Mortality associated with the neutrophil-lymphocyte ratio in septic acute kidney injury requiring continuous renal replacement therapy

BACKGROUND

Sepsis is an important cause of acute kidney injury in intensive care unit patients, accounting for 15% to 20% of renal replacement therapy prescriptions. The neutrophil-lymphocyte ratio (NLR), a marker of systemic inflammation and immune response, was previously associated with the mortality rate in multiple conditions. Herein, we aimed to examine how the NLR relates to the mortality rate in septic acute kidney injury patients requiring continuous renal replacement therapy (CRRT).

METHODS

The NLRs of 6 and 18 were used for dividing NLRs into three groups and, thus, were set higher than those in previous studies accounting for steroid use in sepsis. Cox proportional hazard models were used to calculate hazard ratios of mortality outcomes before and after matching their propensity scores.

RESULTS

A total of 798 septic acute kidney injury patients requiring CRRT were classified into three NLR groups (low, <6 [n = 277]; medium, ≥6 and <18 [n = 115], and high, ≥18 [n = 406], respectively). The in-hospital mortality rates per group were 83.4%, 74.8%, and 70.4%, respectively (p < 0.001). Per the univariable Cox survival analysis after propensity score matching, a high NLR was related to approximately 24% reduced mortality. The survival benefit of the high NLR group compared with the other two groups remained consistent across all subgroups, showing any p for interactions of >0.05.

CONCLUSION

A high NLR is associated with better clinical outcomes, such as low mortality, in septic acute kidney injury patients undergoing CRRT.

Uromodulin in sepsis and severe pneumonia: a two-sample Mendelian randomization study

The outcome for patients with sepsis-associated acute kidney injury in the intensive care unit (ICU) remains poor. Low serum uromodulin (sUMOD) protein levels have been proposed as a causal mediator of this effect. We investigated the effect of different levels of sUMOD on the risk of sepsis and severe pneumonia and outcomes in these conditions. A two-sample Mendelian randomization (MR) study was performed. Single-nucleotide polymorphisms (SNPs) associated with increased levels of sUMOD were identified and used as instrumental variables for association with outcomes. Data from different cohorts were combined based on disease severity and meta-analyzed. Five SNPs associated with increased sUMOD levels were identified and tested in six datasets from two biobanks. There was no protective effect of increased levels of sUMOD on the risk of sepsis [two cohorts, odds ratio (OR) 0.99 (95% confidence interval 0.95-1.03), P = 0.698, and OR 0.95 (0.91-1.00), P = 0.060, respectively], risk of sepsis requiring ICU admission [OR 1.04 (0.93-1.16), P = 0.467], ICU mortality in sepsis [OR 1.00 (0.74-1.37), P = 0.987], risk of pneumonia requiring ICU admission [OR 1.05 (0.98-1.14), P = 0.181], or ICU mortality in pneumonia [OR 1.17 (0.98-1.39), P = 0.079]. Meta-analysis of hospital-admitted and ICU-admitted patients separately yielded similar results [OR 0.98 (0.95-1.01), P = 0.23, and OR 1.05 (0.99-1.12), P = 0.86, respectively]. Among patients with sepsis and severe pneumonia, there was no protective effect of different levels of sUMOD. Results were consistent regardless of geographic origins and not modified by disease severity. NEW & NOTEWORTHY The presence of acute kidney injury in severe infections increases the likelihood of poor outcome severalfold. A decrease in serum uromodulin (sUMOD), synthetized in the kidney, has been proposed as a mediator of this effect. Using the Mendelian randomization technique, we tested the hypothesis that increased sUMOD is protective in severe infections. Analyses, however, showed no evidence of a protective effect of higher levels of sUMOD in sepsis or severe pneumonia.

Knowledge, attitude, practice, needs, and implementation status of intensive care unit staff toward continuous renal replacement therapy: a survey of 66 hospitals in central and South China

BACKGROUND

Continuous renal replacement therapy (CRRT) is a commonly utilized form of renal replacement therapy (RRT) in the intensive care unit (ICU). A specialized CRRT team (SCT, composed of physicians and nurses) engage playing pivotal roles in administering CRRT, but there is paucity of evidence-based research on joint training and management strategies. This study armed to evaluate the knowledge, attitude, and practice (KAP) of ICU staff toward CRRT, and to identify education pathways, needs, and the current status of CRRT implementation.

METHODS

This study was performed from February 6 to March 20, 2023. A self-made structured questionnaire was used for data collection. Descriptive statistics, T-tests, Analysis of variance (ANOVA), multiple linear regression, and Pearson correlation coefficient tests (α = 0.05) were employed.

RESULTS

A total of 405 ICU staff from 66 hospitals in Central and South China participated in this study, yielding 395 valid questionnaires. The mean knowledge score was 51.46 ± 5.96 (61.8% scored highly). The mean attitude score was 58.71 ± 2.19 (73.9% scored highly). The mean practice score was 18.15 ± 0.98 (85.1% scored highly). Multiple linear regression analysis indicated that gender, age, years of CRRT practice, ICU category, and CRRT specialist panel membership independently affected the knowledge score; Educational level, years of CRRT practice, and CRRT specialist panel membership independently affected the attitude score; Education level and teaching hospital employment independently affected the practice score. The most effective method for ICU staff to undergo training and daily work experience is within the department.

CONCLUSION

ICU staff exhibit good knowledge, a positive attitude and appropriately practiced CRRT. Extended CRRT practice time in CRRT, further training in a general ICU or teaching hospital, joining a CRRT specialist panel, and upgraded education can improve CRRT professional level. Considering the convenience of training programs will enhance ICU staff participation. Training should focus on basic CRRT principles, liquid management, and alarm handling.

Acute Kidney Injury Receiving Dialysis and Dialysis Care after Hospital Discharge

The number of patients with AKI receiving outpatient hemodialysis (AKI-D) is increasing. At present, on the basis of limited data, approximately one third of patients with AKI-D who receive outpatient dialysis after hospital discharge survive and regain sufficient kidney function to discontinue dialysis. Data to inform dialysis management strategies that promote kidney function recovery and processes of care among patients with AKI-D receiving outpatient dialysis are lacking. In this article, we detail current trends in the incidence, risk factors, clinical outcomes, proposed management, and health policy landscape for patients with AKI-D receiving outpatient dialysis and identify areas for further research.

Treatment of Acute Kidney Injury: A Review of Current Approaches and Emerging Innovations

Acute kidney injury (AKI) is a complex and life-threatening condition with multifactorial etiologies, ranging from ischemic injury to nephrotoxic exposures. Management is founded on treating the underlying cause of AKI, but supportive care-via fluid management, vasopressor therapy, kidney replacement therapy (KRT), and more-is also crucial. Blood pressure targets are often higher in AKI, and these can be achieved with fluids and vasopressors, some of which may be more kidney-protective than others. Initiation of KRT is controversial, and studies have not consistently demonstrated any benefit to early start dialysis. There are no targeted pharmacotherapies for AKI itself, but some do exist for complications of AKI; additionally, medications become a key aspect of AKI management because changes in renal function and dialysis support can lead to issues with both toxicities and underdosing. This review will cover existing literature on these and other aspects of AKI treatment. Additionally, this review aims to identify gaps and challenges and to offer recommendations for future research and clinical practice.

Personalizing renal replacement therapy initiation in the intensive care unit: a reinforcement learning-based strategy with external validation on the AKIKI randomized controlled trials

OBJECTIVE

The timely initiation of renal replacement therapy (RRT) for acute kidney injury (AKI) requires sequential decision-making tailored to individuals' evolving characteristics. To learn and validate optimal strategies for RRT initiation, we used reinforcement learning on clinical data from routine care and randomized controlled trials.

MATERIALS AND METHODS

We used the MIMIC-III database for development and AKIKI trials for validation. Participants were adult ICU patients with severe AKI receiving mechanical ventilation or catecholamine infusion. We used a doubly robust estimator to learn when to start RRT after the occurrence of severe AKI for three days in a row. We developed a "crude strategy" maximizing the population-level hospital-free days at day 60 (HFD60) and a "stringent strategy" recommending RRT when there is significant evidence of benefit for an individual. For validation, we evaluated the causal effects of implementing our learned strategies versus following current best practices on HFD60.

RESULTS

We included 3748 patients in the development set and 1068 in the validation set. Through external validation, the crude and stringent strategies yielded an average difference of 13.7 [95% CI -5.3 to 35.7] and 14.9 [95% CI -3.2 to 39.2] HFD60, respectively, compared to current best practices. The stringent strategy led to initiating RRT within 3 days in 14% of patients versus 38% under best practices.

DISCUSSION

Implementing our strategies could improve the average number of days that ICU patients spend alive and outside the hospital while sparing RRT for many.

CONCLUSION

We developed and validated a practical and interpretable dynamic decision support system for RRT initiation in the ICU.

Failing kidneys: renal replacement therapies in the ICU

Acute kidney injury (AKI) is one of the most common organ dysfunctions impacting ICU (intensive care unit) patients. Early diagnosis using the various classification systems and interventions that can be aided by use of biomarkers are key in improving outcomes. Once the patient meets criteria of AKI, many patient specific factors determine the optimal timing for and mode of renal replacement therapy. There are several special considerations in surgical ICU patients with AKI including management of intracranial hypertension in those with cerebral edema, anticoagulation in high-risk bleeding patients, and use of contrast imaging. This article provides a focused review of the essential aspects of diagnosis and management of AKI in the critically ill or injured surgical patient.

Influence of fluid accumulation on major adverse kidney events in critically ill patients - an observational cohort study

BACKGROUND

Fluid accumulation (FA) is known to be associated with acute kidney injury (AKI) during intensive care unit (ICU) stay but data on mid-term renal outcome is scarce. The aim of this study was to investigate the association between FA at ICU day 3 and major adverse kidney events in the first 30 days after ICU admission (MAKE30).

METHODS

Retrospective, single-center cohort study including adult ICU patients with sufficient data to compute FA and MAKE30. We defined FA as a positive cumulative fluid balance greater than 5% of bodyweight. The association between FA and MAKE30, including its sub-components, as well as the serum creatinine trajectories during ICU stay were examined. In addition, we performed a sensitivity analysis for the stage of AKI and the presence of chronic kidney disease (CKD).

RESULTS

Out of 13,326 included patients, 1,100 (8.3%) met the FA definition. FA at ICU day 3 was significantly associated with MAKE30 (adjusted odds ratio [aOR] 1.96; 95% confidence interval [CI] 1.67-2.30; p < 0.001) and all sub-components: need for renal replacement therapy (aOR 3.83; 95%CI 3.02-4.84), persistent renal dysfunction (aOR 1.72; 95%CI 1.40-2.12), and 30-day mortality (aOR 1.70; 95%CI 1.38-2.09), p all < 0.001. The sensitivity analysis showed an association of FA with MAKE30 independent from a pre-existing CKD, but exclusively in patients with AKI stage 3. Furthermore, FA was independently associated with the creatinine trajectory over the whole observation period.

CONCLUSIONS

Fluid accumulation is significantly associated with MAKE30 in critically ill patients. This association is independent from pre-existing CKD and strongest in patients with AKI stage 3.

Acute kidney injury in patients with cirrhosis: Acute Disease Quality Initiative (ADQI) and International Club of Ascites (ICA) joint multidisciplinary consensus meeting

Patients with cirrhosis are prone to developing acute kidney injury (AKI), a complication associated with a markedly increased in-hospital morbidity and mortality, along with a risk of progression to chronic kidney disease. Whereas patients with cirrhosis are at increased risk of developing any phenotype of AKI, hepatorenal syndrome (HRS), a specific form of AKI (HRS-AKI) in patients with advanced cirrhosis and ascites, carries an especially high mortality risk. Early recognition of HRS-AKI is crucial since administration of splanchnic vasoconstrictors may reverse the AKI and serve as a bridge to liver transplantation, the only curative option. In 2023, a joint meeting of the International Club of Ascites (ICA) and the Acute Disease Quality Initiative (ADQI) was convened to develop new diagnostic criteria for HRS-AKI, to provide graded recommendations for the work-up, management and post-discharge follow-up of patients with cirrhosis and AKI, and to highlight priorities for further research.

Uplift modeling to predict individual treatment effects of renal replacement therapy in sepsis-associated acute kidney injury patients

Renal replacement therapy (RRT) is a crucial treatment for sepsis-associated acute kidney injury (S-AKI), but it is uncertain which S-AKI patients should receive immediate RRT. Identifying the characteristics of patients who may benefit the most from RRT is an important task. This retrospective study utilized a public database and enrolled S-AKI patients, who were divided into RRT and non-RRT groups. Uplift modeling was used to estimate the individual treatment effect (ITE) of RRT. The validity of different models was compared using a qini curve. After labeling the patients in the validation cohort, we characterized the patients who would benefit the most from RRT and created a nomogram. A total of 8289 patients were assessed, among whom 591 received RRT, and 7698 did not receive RRT. The RRT group had a higher severity of illness than the non-RRT group, with a Sequential Organ Failure Assessment (SOFA) score of 9 (IQR 6,11) vs. 5 (IQR 3,7). The 28-day mortality rate was higher in the RRT group than the non-RRT group (34.83% vs. 14.61%, p < 0.0001). Propensity score matching (PSM) was used to balance baseline characteristics, 458 RRT patients and an equal number of non-RRT patients were enrolled for further research. After PSM, 28-day mortality of RRT and non-RRT groups were 32.3% vs. 39.3%, P = 0.033. Using uplift modeling, we found that urine output, fluid input, mean blood pressure, body temperature, and lactate were the top 5 factors that had the most influence on RRT effect. The area under the uplift curve (AUUC) of the class transformation model was 0.068, the AUUC of SOFA was 0.018, and the AUUC of Kdigo-stage was 0.050. The class transformation model was more efficient in predicting individual treatment effect. A logistic regression model was developed, and a nomogram was drawn to predict whether an S-AKI patient can benefit from RRT. Six factors were taken into account (urine output, creatinine, lactate, white blood cell count, glucose, respiratory rate). Uplift modeling can better predict the ITE of RRT on S-AKI patients than conventional score systems such as Kdigo and SOFA. We also found that white blood cell count is related to the benefits of RRT, suggesting that changes in inflammation levels may be associated with the effects of RRT on S-AKI patients.

Renal replacement therapy initiation strategies in comatose patients with severe acute kidney injury: a secondary analysis of a multicenter randomized controlled trial

PURPOSE

The effect of renal replacement therapy (RRT) in comatose patients with acute kidney injury (AKI) remains unclear. We compared two RRT initiation strategies on the probability of awakening in comatose patients with severe AKI.

METHODS

We conducted a post hoc analysis of a trial comparing two delayed RRT initiation strategies in patients with severe AKI. Patients were monitored until they had oliguria for more than 72 h and/or blood urea nitrogen higher than 112 mg/dL and then randomized to a delayed strategy (RRT initiated after randomization) or a more-delayed one (RRT initiated if complication occurred or when blood urea nitrogen exceeded 140 mg/dL). We included only comatose patients (Richmond Agitation-Sedation scale [RASS] < - 3), irrespective of sedation, at randomization. A multi-state model was built, defining five mutually exclusive states: death, coma (RASS < - 3), incomplete awakening (RASS [- 3; - 2]), awakening (RASS [- 1; + 1] two consecutive days), and agitation (RASS >  + 1). Primary outcome was the transition from coma to awakening during 28 days after randomization.

RESULTS

A total of 168 comatose patients (90 delayed and 78 more-delayed) underwent randomization. The transition intensity from coma to awakening was lower in the more-delayed group (hazard ratio [HR] = 0.36 [0.17-0.78]; p = 0.010). Time spent awake was 10.11 days [8.11-12.15] and 7.63 days [5.57-9.64] in the delayed and the more-delayed groups, respectively. Two sensitivity analyses were performed based on sedation status and sedation practices across centers, yielding comparable results.

CONCLUSION

In comatose patients with severe AKI, a more-delayed RRT initiation strategy resulted in a lower chance of transitioning from coma to awakening.

Timing of renal replacement therapy in patients with sepsis-associated acute kidney injury: A systematic review and meta-analysis

OBJECTIVE

The objective of this study was to evaluate the clinical efficacy of early and delayed renal replacement therapy (RRT) in patients with sepsis-associated acute kidney injury (AKI).

METHODS

We searched three databases (PubMed, Web of Science, and Cochrane) for randomised controlled trials and cohort studies published up to March 28, 2022, and manually searched for relevant references. We included data from adults older than 18 years of age with sepsis-associated AKI. The Newcastle-Ottawa Scale and the Cochrane Risk of Bias tool were used for quality assessment. The primary outcome was 28-day mortality. Relative risk (RR), mean difference (MD), and 95% confidence interval (CI) were used for meta-analysis.

RESULTS

There were a total of 3648 patients from four randomised controlled trials and eight cohort studies. The pooled results indicated that compared to delayed RRT, early RRT had a lower 28-day mortality (RR: 0.72; 95% CI: 0.59-0.88; P = 0.001; I2 = 76%), and this result was robust according to sensitivity analysis, and no significant difference in 90-day mortality (RR: 0.80; 95% CI: 0.64-1.00; P = 0.05; I2 = 82%),180-day mortality (RR: 1.07; 95% CI: 0.93-1.23; P = 0.36; I2 = 0%), length of intensive care unit stay (MD - 0.94; 95% CI -2.43-0.55; P = 0.22; I2 = 0%), length of hospital stay (MD - 1.02; 95% CI -4.21-2.17; P = 0.53; I2 = 0%), and RRT dependence was found among survivors at 28 days (RR: 1.21; 95% CI: 0.73-2.00; P = 0.47; I2 = 0%). Subgroup analysis of 28-day mortality showed that patients with sepsis-associated AKI who received early RRT at Kidney Disease: Improving Global Outcomes stage 2 or Sequential Organ Failure Assessment score ≤12 had a better chance of survival.

CONCLUSIONS

Early RRT may be beneficial to the 28-day short-term survival rate of patients with sepsis-associated AKI in Kidney Disease: Improving Global Outcomes stage 2 and having Sequential Organ Failure Assessment score less than or equal to 12 but has no significant effect on long-term survival, length of intensive care unit stay, the total length of hospital stay, and 28-day RRT dependence of survivors. These results still need to be confirmed by more large-scale randomised controlled studies.

Endothelium-related biomarkers enhanced prediction of kidney support therapy in critically ill patients with non-oliguric acute kidney injury

Acute kidney injury (AKI) is a common condition in hospitalized patients who often requires kidney support therapy (KST). However, predicting the need for KST in critically ill patients remains challenging. This study aimed to analyze endothelium-related biomarkers as predictors of KST need in critically ill patients with stage 2 AKI. A prospective observational study was conducted on 127 adult ICU patients with stage 2 AKI by serum creatinine only. Endothelium-related biomarkers, including vascular cell adhesion protein-1 (VCAM-1), angiopoietin (AGPT) 1 and 2, and syndecan-1, were measured. Clinical parameters and outcomes were recorded. Logistic regression models, receiver operating characteristic (ROC) curves, continuous net reclassification improvement (NRI) and integrated discrimination improvement (IDI) were used for analysis. Among the patients, 22 (17.2%) required KST within 72 h. AGPT2 and syndecan-1 levels were significantly greater in patients who progressed to the KST. Multivariate analysis revealed that AGPT2 and syndecan-1 were independently associated with the need for KST. The area under the ROC curve (AUC-ROC) for AGPT2 and syndecan-1 performed better than did the constructed clinical model in predicting KST. The combination of AGPT2 and syndecan-1 improved the discrimination capacity of predicting KST beyond that of the clinical model alone. Additionally, this combination improved the classification accuracy of the NRI and IDI. AGPT2 and syndecan-1 demonstrated predictive value for the need for KST in critically ill patients with stage 2 AKI. The combination of AGPT2 and syndecan-1 alone enhanced the predictive capacity of predicting KST beyond clinical variables alone. These findings may contribute to the early identification of patients who will benefit from KST and aid in the management of AKI in critically ill patients.

Global Scientific Trends in Continuous Renal Replacement Therapy from 2000 to 2023: A Bibliometric and Visual Analysis

INTRODUCTION

Continuous renal replacement therapy (CRRT) is one of the most widely used blood purification and organ support methods in the ICU. However, the development process, the current status, hotspots, and future trends of CRRT remain unclear.

METHOD

The WoSCC database was used to analyze CRRT research evolution and theme trends. VOSviewer was used to construct coauthorship, co-occurrence, co-citation, and network visualizations. CiteSpace is used to detect bursts for co-occurrence items. Several important subtopics were reviewed and discussed in more detail.

RESULTS

Global publications increased from 56 in 2000 to 398 in 2023, a 710.71% increase. Blood Purification published the most manuscripts, followed by the International Journal of Artificial Organs. The USA, the San Bortolo Hospital, and Bellomo were the most productive and impactful institution, country, and author, respectively. Based on co-occurrence cluster analysis, five clusters emerged: (1) clinical applications and management of CRRT; (2) sepsis and CRRT; (3) CRRT anticoagulant management; (4) CRRT and antibiotic pharmacokinetics and pharmacodynamics; and (5) comparison of CRRT and intermittent hemodialysis. COVID-19, initiation, ECOMO, cefepime, guidelines, cardiogenic shock, biomarker, and outcome were the latest high-frequency keywords or strongest bursts, indicating the emerging frontiers of CRRT.

CONCLUSIONS

There has been widespread publication and citation of CRRT research in the past 2 decades. We provide an overview of current trends, global collaboration patterns, basic knowledge, research hotspots, and emerging frontiers.

Regional Practice Variation and Outcomes in the Standard Versus Accelerated Initiation of Renal Replacement Therapy in Acute Kidney Injury (STARRT-AKI) Trial: A Post Hoc Secondary Analysis

OBJECTIVES

Among patients with severe acute kidney injury (AKI) admitted to the ICU in high-income countries, regional practice variations for fluid balance (FB) management, timing, and choice of renal replacement therapy (RRT) modality may be significant.

DESIGN

Secondary post hoc analysis of the STandard vs. Accelerated initiation of Renal Replacement Therapy in Acute Kidney Injury (STARRT-AKI) trial (ClinicalTrials.gov number NCT02568722).

SETTING

One hundred-fifty-three ICUs in 13 countries.

PATIENTS

Altogether 2693 critically ill patients with AKI, of whom 994 were North American, 1143 European, and 556 from Australia and New Zealand (ANZ).

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Total mean FB to a maximum of 14 days was +7199 mL in North America, +5641 mL in Europe, and +2211 mL in ANZ (p < 0.001). The median time to RRT initiation among patients allocated to the standard strategy was longest in Europe compared with North America and ANZ (p < 0.001; p < 0.001). Continuous RRT was the initial RRT modality in 60.8% of patients in North America and 56.8% of patients in Europe, compared with 96.4% of patients in ANZ (p < 0.001). After adjustment for predefined baseline characteristics, compared with North American and European patients, those in ANZ were more likely to survive to ICU (p < 0.001) and hospital discharge (p < 0.001) and to 90 days (for ANZ vs. Europe: risk difference [RD], -11.3%; 95% CI, -17.7% to -4.8%; p < 0.001 and for ANZ vs. North America: RD, -10.3%; 95% CI, -17.5% to -3.1%; p = 0.007).

CONCLUSIONS

Among STARRT-AKI trial centers, significant regional practice variation exists regarding FB, timing of initiation of RRT, and initial use of continuous RRT. After adjustment, such practice variation was associated with lower ICU and hospital stay and 90-day mortality among ANZ patients compared with other regions.

Weaning from Kidney Replacement Therapy in the Critically Ill Patient with Acute Kidney Injury

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

The influence of gender on the epidemiology of and outcome from sepsis associated acute kidney injury in ICU: a retrospective propensity-matched cohort study

PURPOSES

The influence of gender on the epidemiology of and outcome from SA-AKI in ICU has not been fully clarified. Our aim is to elucidate these differences.

METHODS

This study included adult patients with sepsis in MIMIC IV (V 2.2), and propensity matching analysis, cox regression and logistic regression were used to analyze gender differences in incidence, mortality and organ support rate.

RESULTS

Of the 24,467 patients included in the cohort, 18,128 were retained after propensity score matching. In the matched cohort, the incidence of SA-AKI in males is higher than that in females (58.6% vs. 56.2%; P = 0.001).males were associated with a higher risk of SA-AKI (OR:1.07(1.01-1.14), P = 0.026;adjusted OR:1.07(1.01-1.14), P < 0.033).In SA-AKI patients, males were associated with a lower risk of ICU mortality(HR:0.803(0.721-0.893), P < 0.001;adjusted HR:0.836(0.746-0.937), P = 0.002) and in-hospital mortality(HR: 0.820(0.748-0.899), P < 0.001;adjusted HR:0.853(0.775-0.938), P = 0.003).there were no statistically significant differences between male and female patients in 1-year all-cause mortality (36.9% vs. 35.8%, P = 0.12), kidney replacement therapy rate (7.8% vs.7.4%, P = 0.547), mechanical ventilation rate 64.8% vs.63.9%, P = 0.369), and usage of vasoactive drugs (55.4% vs. 54.6%, P = 0.418).

CONCLUSIONS

Gender may affect the incidence and outcomes of SA-AKI, further research is needed to fully understand the impact of gender on SA-AKI patients.

Navigating the Labyrinth: Intensive Care Challenges for Patients with Acute-on-Chronic Liver Failure

Acute-on-chronic liver failure (ACLF) refers to the deterioration of liver function in individuals who already have chronic liver disease. In the setting of ACLF, liver damage leads to the failure of other organs and is associated with increased short-term mortality. Optimal medical management of patients with ACLF requires implementing complex treatment strategies, often in an intensive care unit (ICU). Failure of organs other than the liver distinguishes ACLF from other critical illnesses. Although there is growing evidence supporting the current approach to ACLF management, the mortality associated with this condition remains unacceptably high. In this review, we discuss considerations for ICU care of patients with ACLF and highlight areas for further research.

Fluid Resuscitation and Sepsis Management in Patients with Chronic Kidney Disease or End-Stage Renal Disease: Scoping Review

Managing sepsis and fluid resuscitation in patients with chronic kidney disease or end-stage renal disease is challenging for health care providers. Nurses are essential for early identification and treatment of these patients. Nurse education on assessing perfusion and implementing 3-hour bundled care can improve mortality rates in patients with sepsis. In this scoping review, initial screening identified 1176 articles published from 2015 through 2023 in the National Library of Medicine database; 29 articles were included in the literature summary and evidence synthesis. A systematic review meta-analysis was not possible because of data heterogeneity. The review revealed that most patients with chronic kidney disease or end-stage renal disease received more conservative resuscitation than did the general population, most likely because of concerns about volume overload. However, patients with chronic kidney disease or end-stage renal disease could tolerate the standard initial fluid resuscitation bolus of 30 mL/kg for sepsis. Outcomes in patients with chronic kidney disease or end-stage renal disease were similar to outcomes in patients without those conditions, whether they received standard or conservative fluid resuscitation. Patients who received the standard (higher) fluid resuscitation volume did not have increased rates of complications such as longer duration of mechanical ventilation, increased mortality, or prolonged length of stay. Using fluid responsiveness to guide resuscitation was associated with improved outcomes. The standard initial fluid resuscitation bolus of 30 mL/kg may be safe for patients with chronic kidney disease or end-stage renal disease and sepsis. Fluid responsiveness could be a valuable resuscitation criterion, promoting better decision-making by multidisciplinary teams. Further research is required.

[Guideline-conform treatment of sepsis]

The time to administration of broad-spectrum antibiotics and (secondarily) to the initiation of hemodynamic stabilization are the most important factors influencing survival of patients with sepsis and septic shock; however, the basic prerequisite for the initiation of an adequate treatment is that a suspected diagnosis of sepsis is made first. Therefore, the treatment of sepsis, even before it has begun, is an interdisciplinary and interprofessional task. This article provides an overview of the current state of the art in sepsis treatment and points towards new evidence that has the potential to change guideline recommendations in the coming years. In summary, the following points are critical: (1) sepsis must be diagnosed as soon as possible and the implementation of a source control intervention (in case of a controllable source) has to be implemented as soon as (logistically) possible. (2) In general, intravenous broad-spectrum antibiotics should be given within the first hour after diagnosis if sepsis or septic shock is suspected. In organ dysfunction without shock, where sepsis is a possible but unlikely cause, the results of focused advanced diagnostics should be awaited before a decision to give broad-spectrum antibiotics is made. If it is not clear within 3 h whether sepsis is the cause, broad-spectrum antibiotics should be given when in doubt. Administer beta-lactam antibiotics as a prolonged (or if therapeutic drug monitoring is available, continuous) infusion after an initial loading dose. (3) Combination treatment with two agents for one pathogen group should remain the exception (e.g. multidrug-resistant gram-negative pathogens). (4) In the case of doubt, the duration of anti-infective treatment should rather be shorter than longer. Procalcitonin can support the clinical decision to stop (not to start!) antibiotic treatment! (5) For fluid treatment, if hypoperfusion is present, the first (approximately) 2L (30 ml/kg BW) of crystalloid solution is usually safe and indicated. After that, the rule is: less is more! Any further fluid administration should be carefully weighed up with the help of dynamic parameters, the patient's clinical condition and echo(cardio)graphy.

Sepsis-associated acute kidney injury-treatment standard

Sepsis is a host's deleterious response to infection, which could lead to life-threatening organ dysfunction. Sepsis-associated acute kidney injury (SA-AKI) is the most frequent organ dysfunction and is associated with increased morbidity and mortality. Sepsis contributes to ≈50% of all AKI in critically ill adult patients. A growing body of evidence has unveiled key aspects of the clinical risk factors, pathobiology, response to treatment and elements of renal recovery that have advanced our ability to detect, prevent and treat SA-AKI. Despite these advancements, SA-AKI remains a critical clinical condition and a major health burden, and further studies are needed to diminish the short and long-term consequences of SA-AKI. We review the current treatment standards and discuss novel developments in the pathophysiology, diagnosis, outcome prediction and management of SA-AKI.

Unsupervised clustering identifies sub-phenotypes and reveals novel outcome predictors in patients with dialysis-requiring sepsis-associated acute kidney injury

INTRODUCTION

Heterogeneity exists in sepsis-associated acute kidney injury (SA-AKI). This study aimed to perform unsupervised consensus clustering in critically ill patients with dialysis-requiring SA-AKI.

PATIENTS AND METHODS

This prospective observational cohort study included all septic patients, defined by the Sepsis-3 criteria, with dialysis-requiring SA-AKI in surgical intensive care units in Taiwan between 2009 and 2018. We employed unsupervised consensus clustering based on 23 clinical variables upon initializing renal replacement therapy. Multivariate-adjusted Cox regression models and Fine-Gray sub-distribution hazard models were built to test associations between cluster memberships with mortality and being free of dialysis at 90 days after hospital discharge, respectively.

RESULTS

Consensus clustering among 999 enrolled patients identified three sub-phenotypes characterized with distinct clinical manifestations upon renal replacement therapy initiation (n = 352, 396 and 251 in cluster 1, 2 and 3, respectively). They were followed for a median of 48 (interquartile range 9.5-128.5) days. Phenotypic cluster 1, featured by younger age, lower Charlson Comorbidity Index, higher baseline estimated glomerular filtration rate but with higher severity of acute illness was associated with an increased risk of death (adjusted hazard ratio of 3.05 [95% CI, 2.35-3.97]) and less probability to become free of dialysis (adjusted sub-distribution hazard ratio of 0.55 [95% CI, 0.38-0.8]) than cluster 3. By examining distinct features of the sub-phenotypes, we discovered that pre-dialysis hyperlactatemia ≥3.3 mmol/L was an independent outcome predictor. A clinical model developed to determine high-risk sub-phenotype 1 in this cohort (C-static 0.99) can identify a sub-phenotype with high in-hospital mortality risk (adjusted hazard ratio of 1.48 [95% CI, 1.25-1.74]) in another independent multi-centre SA-AKI cohort.

CONCLUSIONS

Our data-driven approach suggests sub-phenotypes with clinical relevance in dialysis-requiring SA-AKI and serves an outcome predictor. This strategy represents further development toward precision medicine in the definition of high-risk sub-phenotype in patients with SA-AKI.Key messagesUnsupervised consensus clustering can identify sub-phenotypes of patients with SA-AKI and provide a risk prediction.Examining the features of patient heterogeneity contributes to the discovery of serum lactate levels ≥ 3.3 mmol/L upon initializing RRT as an independent outcome predictor.This data-driven approach can be useful for prognostication and lead to a better understanding of therapeutic strategies in heterogeneous clinical syndromes.

Real-Time Acute Kidney Injury Risk Stratification-Biomarker Directed Fluid Management Improves Outcomes in Critically Ill Children and Young Adults

Introduction

Critically ill admitted patients are at high risk of acute kidney injury (AKI). The renal angina index (RAI) and urinary biomarker neutrophil gelatinase-associated lipocalin (uNGAL) can aid in AKI risk assessment. We implemented the Trial in AKI using NGAL and Fluid Overload to optimize CRRT Use (TAKING FOCUS 2; TF2) to personalize fluid management and continuous renal replacement therapy (CRRT) initiation based on AKI risk and patient fluid accumulation. We compared outcomes pre-TF2 and post-TF2 initiation.

Methods

Patients admitted from July 2017 were followed-up prospectively with the following: (i) an automated RAI result at 12 hours of admission, (ii) a conditional uNGAL order for RAI ≥8, and (iii) a CRRT initiation goal at 10% to 15% weight-based fluid accumulation.

Results

A total of 286 patients comprised 304 intensive care unit (ICU) RAI+ admissions; 178 patients received CRRT over the observation period (2014-2021). Median time from ICU admission to CRRT initiation was 2 days shorter (P < 0.002), and ≥15% pre-CRRT fluid accumulation rate was lower in the TF2 era (P < 0.02). TF2 ICU length of stay (LOS) after CRRT discontinuation and total ICU LOS were 6 and 11 days shorter for CRRT survivors (both P < 0.02). Survival rates to ICU discharge after CRRT discontinuation were higher in the TF2 era (P = 0.001). These associations persisted in each TF2 year; we estimate a conservative $12,500 health care cost savings per CRRT patient treated after TF2 implementation.

Conclusion

We suggest that automated clinical decision support (CDS) combining risk stratification and AKI biomarker assessment can produce durable reductions in pediatric CRRT patient morbidity.

Perioperative Acute Kidney Injury: Implications, Approach, Prevention

Acute kidney injury remains a common and significant contributor to perioperative morbidity. Acute kidney injury worsens patient outcomes, and anesthesiologists should make significant efforts to prevent, assess, and treat perioperative renal injury. The authors discuss the impact of renal injury on patient outcomes and putative underlying mechanisms, evidence underlying treatments for acute kidney injury, and practices that may prevent the development of perioperative renal injury.

Positive single-center randomized trials and subsequent multicenter randomized trials in critically ill patients: a systematic review

BACKGROUND

It is unclear how often survival benefits observed in single-center randomized controlled trials (sRCTs) involving critically ill patients are confirmed by subsequent multicenter randomized controlled trials (mRCTs). We aimed to perform a systemic literature review of sRCTs with a statistically significant mortality reduction and to evaluate whether subsequent mRCTs confirmed such reduction.

METHODS

We searched PubMed for sRCTs published in the New England Journal of Medicine, JAMA, or Lancet, from inception until December 31, 2016. We selected studies reporting a statistically significant mortality decrease using any intervention (drug, technique, or strategy) in adult critically ill patients. We then searched for subsequent mRCTs addressing the same research question tested by the sRCT. We compared the concordance of results between sRCTs and mRCTs when any mRCT was available. We registered this systematic review in the PROSPERO International Prospective Register of Systematic Reviews (CRD42023455362).

RESULTS

We identified 19 sRCTs reporting a significant mortality reduction in adult critically ill patients. For 16 sRCTs, we identified at least one subsequent mRCT (24 trials in total), while the interventions from three sRCTs have not yet been addressed in a subsequent mRCT. Only one out of 16 sRCTs (6%) was followed by a mRCT replicating a significant mortality reduction; 14 (88%) were followed by mRCTs with no mortality difference. The positive finding of one sRCT (6%) on intensive glycemic control was contradicted by a subsequent mRCT showing a significant mortality increase. Of the 14 sRCTs referenced at least once in international guidelines, six (43%) have since been either removed or suggested against in the most recent versions of relevant guidelines.

CONCLUSION

Mortality reduction shown by sRCTs is typically not replicated by mRCTs. The findings of sRCTs should be considered hypothesis-generating and should not contribute to guidelines.

Acute renal injury after aortic arch reconstruction with cardiopulmonary bypass for children: prediction models by machine learning of a retrospective cohort study

BACKGROUND

Acute renal injury (AKI) after aortic arch reconstruction with cardiopulmonary bypass leads to injury of multiple organs and increases perioperative mortality. The study was performed to explore risk factors for AKI. We aim to develop a prediction model that can be used to accurately predict AKI through machine learning (ML).

METHODS

A retrospective analysis was performed on 134 patients with aortic arch reconstruction with cardiopulmonary bypass who were treated at our hospital from January 2002 to January 2022. Risk factors for AKI were compositive and were evaluated with comprehensive analyses. Six artificial intelligence (AI) models were used for machine learning to build prediction models and to screen out the best model to predict AKI.

RESULTS

Weight, eGFR, cyanosis, PDA, newborn birth and duration of renal ischemia were closely related to AKI. By integrating the results of the training cohort and validation cohort, we finally confirmed that the logistic regression model was the most stable model among all the models, and the logistic regression model showed good discrimination, calibration and clinical practicability. Based on 6 independent factors, the dynamic nomogram can be used as a predictive tool for clinical application.

CONCLUSIONS

DHCA could be considered in aortic arch reconstruction if additional perfusion of lower body were not performed especially when renal ischemia is greater than 30 min. Machine Learning models should be developed for early recognition of AKI.

TRIAL REGISTRATION

ChiCTR, ChiCTR2200060552. Registered 4 june 2022.

Development and validation of a nomogram to predict the risk of renal replacement therapy among acute kidney injury patients in intensive care unit

BACKGROUND

There are no universally accepted indications to initiate renal replacement therapy (RRT) among patients with acute kidney injury (AKI). This study aimed to develop a nomogram to predict the risk of RRT among AKI patients in intensive care unit (ICU).

METHODS

In this retrospective cohort study, we extracted AKI patients from Medical Information Mart for Intensive Care III (MIMIC-III) database. Patients were randomly divided into a training cohort (70%) and a validation cohort (30%). Multivariable logistic regression based on Akaike information criterion was used to establish the nomogram. The discrimination and calibration of the nomogram were evaluated by Harrell's concordance index (C-index) and Hosmer-Lemeshow (HL) test. Decision curve analysis (DCA) was performed to evaluate clinical application.

RESULTS

A total of 7413 critically ill patients with AKI were finally enrolled. 514 (6.9%) patients received RRT after ICU admission. 5194 (70%) patients were in the training cohort and 2219 (30%) patients were in the validation cohort. Nine variables, namely, age, hemoglobin, creatinine, blood urea nitrogen and lactate at AKI detection, comorbidity of congestive heart failure, AKI stage, and vasopressor use were included in the nomogram. The predictive model demonstrated satisfying discrimination and calibration with C-index of 0.938 (95% CI, 0.927-0.949; HL test, P = 0.430) in training set and 0.935 (95% CI, 0.919-0.951; HL test, P = 0.392) in validation set. DCA showed a positive net benefit of our nomogram.

CONCLUSION

The nomogram developed in this study was highly accurate for RRT prediction with potential application value.

The intensity of organ support: Restrictive or aggressive therapy for critically ill patients

The intensity of organ support has received attention in recent years. To make better clinical decisions, we should understand the mechanisms and benefits, and disadvantages of the different intensities of organ support in critically ill patients. Therapeutic strategies such as supplemental oxygen therapy, mechanical ventilation, respiratory stimulant, vasoactive agents, transfusion, albumin infusion, fluid management, renal placement, and nutrition support, if they are implemented in accordance with an aggressive strategy, could result in side effects and/or complications, resulting in iatrogenic harm in critically ill patients. It is found that the intensity of organ support is not a determining factor in prognosis. A normal rather than supernormal physiological target is recommended for support therapy.

Blood Purification in Patients with Sepsis Associated with Acute Kidney Injury: A Narrative Review

Sepsis leads to organ dysfunction. Acute kidney injury, a common type of organ dysfunction, is associated with a high mortality rate in patients with sepsis. Kidney replacement therapy can correct the metabolic, electrolyte, and fluid imbalances caused by acute kidney injury. While this therapy can improve outcomes, evidence of its beneficial effects is lacking. Herein, we review the indications for blood purification therapy, including kidney replacement therapy, and the current knowledge regarding acute kidney injury in terms of renal and non-renal indications. While renal indications have been well-documented, indications for blood purification therapy in sepsis (non-renal indications) remain controversial. Excessive inflammation is an important factor in the development of sepsis; blood purification therapy has been shown to reduce inflammatory mediators and improve hemodynamic instability. Given the pathophysiology of sepsis, blood purification therapy may decrease mortality rates in these patients. Further trials are needed in order to establish the effectiveness of blood purification therapy for sepsis.

The Evolution and Future of Intensive Care Management in the Era of Telecritical Care and Artificial Intelligence

Critical care practice has been embodied in the healthcare system since the institutionalization of intensive care units (ICUs) in the late '50s. Over time, this sector has experienced many changes and improvements in providing immediate and dedicated healthcare as patients requiring intensive care are often frail and critically ill with high mortality and morbidity rates. These changes were aided by innovations in diagnostic, therapeutic, and monitoring technologies, as well as the implementation of evidence-based guidelines and organizational structures within the ICU. In this review, we examine these changes in intensive care management over the past 40 years and their impact on the quality of care available to patients. Moreover, the current state of intensive care management is characterized by a multidisciplinary approach and the use of innovative technologies and research databases. Advancements such as telecritical care and artificial intelligence are being increasingly explored, especially since the COVID-19 pandemic, to reduce the length of hospitalization and ICU mortality. With these advancements in intensive care and ever-changing patient needs, critical care experts, hospital managers, and policymakers must also explore appropriate organizational structures and future enhancements within the ICU.

Incidence, Outcomes, and Predictors of Subphenotypes of Acute Kidney Injury among Acute Respiratory Distress Syndrome Patients: A Prospective Observational Study

Background

Acute kidney injury (AKI) is a heterogeneous syndrome with subphenotypes. Acute kidney injury is one of the most common complications in acute respiratory distress syndrome (ARDS) patients, which influences mortality.

Material and methods

It was a single-center observational study on 266 ARDS patients on invasive mechanical ventilation (IMV) to determine the subphenotypes of AKI associated with ARDS. Subphenotyping was done based on the serum creatinine (SCr) trajectories from day 1 to day 5 of IMV into resolving (subphenotype 1) or non-resolving (subphenotype 2) AKI.

Results

Out of 266 ARDS patients, 222 patients were included for data analysis. 141 patients (63.51%) had AKI. The incidence of subphenotype 2 AKI among the ARDS cohort was 78/222 (35.13%). Subphenotype 2 AKI was significantly more among the non-survivors (87.7% vs 36.2 %, p < 0.001). Subphenotype 2 AKI was an independent predictor of mortality among ARDS patients (p < 0.001, adjusted odds ratio 8.978, 95% CI [2.790-28.89]. AKI subphenotype 1 had higher median day 1 SCr than subphenotype 2 but lower levels by day 3 and day 5 of IMV. The median time of survival was 8 days in AKI subphenotype 2 vs 45 days in AKI with subphenotype 1 [Log-Rank (Mantel-Cox) p < 0.001]. The novel DRONE score (Driving pressure, Oxygenation, and Nutritional Evaluation) ≥ 4 predicted subphenotype 2 AKI.

Conclusion

The incidence of subphenotype 2 (non-resolving) AKI among ARDS patients on IMV was about 35% (vs 20% subphenotype 1 AKI), and it was an independent predictor of mortality. The DRONE score ≥4 can predict the AKI subphenotype 2.

Highlights

The serum creatinine trajectory-based subphenotype of AKI (resolving vs non-resolving) determines survival in ARDS patients. Non-resolving AKI subphenotype 2 is an independent predictor of mortality in ARDS. The novel DRONE score (driving pressure, oxygenation, and nutritional evaluation) ≥ 4 within 48 hours of IMV predicted the AKI subphenotype 2 among ventilated ARDS patients.

How to cite this article

Todur P, Nileshwar A, Chaudhuri S, Srinivas T. Incidence, Outcomes, and Predictors of Subphenotypes of Acute Kidney Injury among Acute Respiratory Distress Syndrome Patients: A Prospective Observational Study. Indian J Crit Care Med 2023;27(10):724-731.

Anesthesia and Critical Care for the Prediction and Prevention for Small-for-size Syndrome: Guidelines from the ILTS-iLDLT-LTSI Consensus Conference

BACKGROUND

During the perioperative period of living donor liver transplantation, anesthesiologists and intensivists may encounter patients in receipt of small grafts that puts them at risk of developing small for size syndrome (SFSS).

METHODS

A scientific committee (106 members from 21 countries) performed an extensive literature review on aspects of SFSS with proposed recommendations. Recommendations underwent a blinded review by an independent expert panel and discussion/voting on the recommendations occurred at a consensus conference organized by the International Liver Transplantation Society, International Living Donor Liver Transplantation Group, and Liver Transplantation Society of India.

RESULTS

It was determined that centers with experience in living donor liver transplantation should utilize potential small for size grafts. Higher risk recipients with sarcopenia, cardiopulmonary, and renal dysfunction should receive small for size grafts with caution. In the intraoperative phase, a restrictive fluid strategy should be considered along with routine use of cardiac output monitoring, as well as use of pharmacologic portal flow modulation when appropriate. Postoperatively, these patients can be considered for enhanced recovery and should receive proactive monitoring for SFSS, nutrition optimization, infection prevention, and consideration for early renal replacement therapy for avoidance of graft congestion.

CONCLUSIONS

Our recommendations provide a framework for the optimal anesthetic and critical care management in the perioperative period for patients with grafts that put them at risk of developing SFSS. There is a significant limitation in the level of evidence for most recommendations. This statement aims to provide guidance for future research in the perioperative management of SFSS.

Critically ill patients with acute kidney injury: clinical determinants and post-mortem histology

Background

Acute kidney injury (AKI) requiring renal replacement therapy (RRT) in the intensive care unit (ICU) portends a poor prognosis. We aimed to better characterize predictors of survival and the mechanism of kidney failure in these patients.

Methods

This was a retrospective observational study using clinical and radiological electronic health records, analysed by univariable and multivariable binary logistic regression. Histopathological examination of post-mortem renal tissue was performed.

Results

Among 157 patients with AKI requiring RRT, higher serum creatinine at RRT initiation associated with increased ICU survival [odds ratio (OR) 0.33, 95% confidence interval (CI) 0.17-0.62, P = .001]; however, muscle mass (a marker of frailty) interacted with creatinine (P = .02) and superseded creatinine as a predictor of survival (OR 0.26, 95% CI 0.08-0.82; P = .02). Achieving lower cumulative fluid balance (mL/kg) predicted ICU survival (OR 1.01, 95% CI 1.00-1.01, P < .001), as supported by sensitivity analyses showing improved ICU survival with the use of furosemide (OR 0.40, 95% CI 0.18-0.87, P = .02) and increasing net ultrafiltration (OR 0.97, 95% CI 0.95-0.99, P = .02). A urine output of >500 mL/24 h strongly predicted successful liberation from RRT (OR 0.125, 95% CI 0.05-0.35, P < .001). Post-mortem reports were available for 32 patients; clinically unrecognized renal findings were described in 6 patients, 1 of whom had interstitial nephritis. Experimental staining of renal tissue from patients with sepsis-associated AKI (S-AKI) showed glomerular loss of synaptopodin (P = .02).

Conclusions

Confounding of creatinine by muscle mass undermines its use as a marker of AKI severity in clinical studies. Volume management and urine output are key determinants of outcome. Loss of synaptopodin implicates glomerular injury in the pathogenesis of S-AKI.

The benefits of early continuous renal replacement therapy in critically ill patients with acute kidney injury at high-altitude areas: a retrospective multi-center cohort study

Severe hypoxia would aggravate the acute kidney injury (AKI) in high-altitude areas and continuous renal replacement therapy (CRRT) has been used to treat critically ill patients with AKI. However, the characteristics and outcomes of CRRT in critically ill patients at AKI in high altitudes and the optimal timing of CRRT initiation remain unclear. 1124 patients were diagnosed with AKI and treated with CRRT in the ICU, comprising a high-altitude group (n = 648) and low-altitude group (n = 476). Compared with the low-altitude group, patients with AKI at high altitude showed longer CRRT (4.8 vs. 3.7, P = 0.036) and more rapid progression of AKI stages (P < 0.01), but without any significant minor or major bleeding episodes (P > 0.05). Referring to the analysis of survival and kidney recovery curves, a higher mortality but a lower possibility of renal recovery was observed in the high-altitude group (P < 0.001). However, in the high-altitude group, the survival rate of early CRRT initiation was significantly higher than that of delayed CRRT initiation (P < 0.001). The findings showed poorer clinical outcomes in patients undergoing CRRT for AKI at high altitudes. CRRT at high altitudes was unlikely to increase the adverse events. Moreover, early CRRT initiation might reduce the mortality and promote renal recovery in high-altitude patients.

A clinical model to predict successful renal replacement therapy (RRT) discontinuation in patients with Acute Kidney Injury (AKI)

INTRODUCTION

Ideal timing of Renal Replacement Therapy (RRT) discontinuation in Acute Kidney Injury (AKI) is still unknown. We aimed to study the role of creatinine-related variables in predicting RRT successful discontinuation and to propose a clinical predictive score.

METHODS

In this single-centre retrospective study, we evaluated all AKI patients in whom RRT was interrupted for at least 48 hours. Patients who were still RRT-independent 7 days after initial RRT cessation were included in the "Success" group and opposed to the "Failure" group. We evaluated baseline characteristics and variables collected at the time of RRT interruption, as well as the Kinetic estimated Glomerular Filtration Rate (KeGFR), the simple variation in serum Creatinine (ΔsCr), and the incremental creatinine ratio on the first three days after RRT interruption. Multivariable analysis was performed to evaluate prediction of success. Internal validation using a simple binomial generalized regression model with Lasso estimation and 5-fold cross validation method was performed.

RESULTS

We included 124 patients, 49 in the "Failure" group and 75 in the "Success" group. All creatinine-related variables predicted success in simple and multiple logistic regression models. The best model generated a clinical score based on the odds ratio obtained for each variable and included urine output, non-renal SOFA score, fluid balance, serum urea, serum potassium, blood pH, and the variation in sCr values after RRT discontinuation. The score presented an area under the ROC of 0.86 (95% CI 0.76‒1.00).

CONCLUSION

Creatinine variation between the first 2 consecutive days after RRT discontinuation might predict success in RRT discontinuation. The developed clinical score based on these variables might be a useful clinical decision tool to guide hemodialysis catheter safe removal.

Acute kidney injury in the critical care setting

Acute kidney injury is a sudden reduction in renal function which impairs the kidneys' ability to maintain fluid, electrolyte and acid-base balance. The syndrome often develops secondary to severe illness and is associated with a significant increase in morbidity and mortality rate in critically ill patients. This article gives an overview of the pathophysiology and aetiology of acute kidney injury, as well as the associated complications and clinical diagnostic signs. The authors also describe some common causes of the syndrome in critically ill patients, specifically sepsis, liver failure and cardiac failure, and discuss patient management in the critical care setting, with a focus on haemodynamic support and continuous renal replacement therapy.

Roles of noncoding RNAs in septic acute kidney injury

Septic acute kidney injury (SAKI) is one of the most common and life-threatening complications of sepsis. Patients with SAKI have increased mortality. However, the underlying pathogenesis is unclear, and the treatment targeting SAKI is unsatisfactory. Thus, identifying optimal biomarkers for SAKI diagnosis and treatment is an urgent requisite. Accumulating evidence indicates that noncoding RNAs (ncRNAs) are involved in the occurrence and progression of SAKI. In the present review, we summarized the studies of ncRNAs in SAKI, including microRNAs (miRNAs), long ncRNAs (lncRNAs), and circular RNAs (circRNAs). The ncRNAs are divided into protective and damage factors according to their role in SAKI, and their expression patterns, functions, and molecular mechanisms were elaborated. Next, we proposed that ncRNAs have the potential to be diagnostic and prognostic biomarkers for SAKI and as new therapeutic targets. This review aimed to provide a comprehensive overview of ncRNAs in SKAI and explored the clinical value of ncRNAs as ideal biomarkers of SAKI.

Extracorporeal blood purification therapies for sepsis-associated acute kidney injury in critically ill patients: expert opinion from the SIAARTI-SIN joint commission

Sepsis-Associated Acute Kidney Injury is a life-threatening condition leading to high morbidity and mortality in critically ill patients admitted to the intensive care unit. Over the past decades, several extracorporeal blood purification therapies have been developed for both sepsis and sepsis-associated acute kidney injury management. Despite the widespread use of extracorporeal blood purification therapies in clinical practice, it is still unclear when to start this kind of treatment and how to define its efficacy. Indeed, several questions on sepsis-associated acute kidney injury and extracorporeal blood purification therapy still remain unresolved, including the indications and timing of renal replacement therapy in patients with septic vs. non-septic acute kidney injury, the optimal dialysis dose for renal replacement therapy modalities in sepsis-associated acute kidney injury patients, and the rationale for using extracorporeal blood purification therapies in septic patients without acute kidney injury. Moreover, the development of novel extracorporeal blood purification therapies, including those based on the use of adsorption devices, raised the attention of the scientific community both on the clearance of specific mediators released by microorganisms and by injured cells and potentially involved in the pathogenic mechanisms of organ dysfunction including sepsis-associated acute kidney injury, and on antibiotic removal. Based on these considerations, the joint commission of the Italian Society of Anesthesiology and Critical Care (SIAARTI) and the Italian Society of Nephrology (SIN) herein addressed some of these issues, proposed some recommendations for clinical practice and developed a common framework for future clinical research in this field.

Differential effect on mortality of the timing of initiation of renal replacement therapy according to the criteria used to diagnose acute kidney injury: an IDEAL-ICU substudy

BACKGROUND

This substudy of the randomized IDEAL-ICU trial assessed whether the timing of renal replacement therapy (RRT) initiation has a differential effect on 90-day mortality, according to the criteria used to diagnose acute kidney injury (AKI), in patients with early-stage septic shock.

METHODS

Three groups were considered according to the criterion defining AKI: creatinine elevation only (group 1), reduced urinary output only (group 2), creatinine elevation plus reduced urinary output (group 3). Primary outcome was 90-day all-cause death. Secondary endpoints were RRT-free days, RRT dependence and renal function at discharge. We assessed the interaction between RRT strategy (early vs. delayed) and group, and the association between RRT strategy and mortality in each group by logistic regression.

RESULTS

Of 488 patients enrolled, 205 (42%) patients were in group 1, 174 (35%) in group 2, and 100 (20%) in group 3. The effect of RRT initiation strategy on 90-day mortality across groups showed significant heterogeneity (adjusted interaction p = 0.021). Mortality was 58% vs. 42% for early vs. late RRT initiation, respectively, in group 1 (p = 0.028); 57% vs. 67%, respectively, in group 2 (p = 0.18); and 58% vs. 55%, respectively, in group 3 (p = 0.79). There was no significant difference in secondary outcomes.

CONCLUSION

The timing of RRT initiation has a differential impact on outcome according to AKI diagnostic criteria. In patients with elevated creatinine only, early RRT initiation was associated with significantly increased mortality. In patients with reduced urine output only, late RRT initiation was associated with a nonsignificant, 10% absolute increase in mortality.

Predicting the Development of Renal Replacement Therapy Indications by Combining the Furosemide Stress Test and Chemokine (C-C Motif) Ligand 14 in a Cohort of Postsurgical Patients

OBJECTIVES

Optimal timing of renal replacement therapy (RRT) initiation in severe acute kidney injury (AKI) remains controversial. Initiation of treatment early in the course of AKI may lead to some patients undergoing unnecessary RRT, whereas delayed treatment is associated with increased mortality. This study aims to investigate whether the combination of the furosemide stress test (FST) and AKI-associated biomarkers can predict the development of indications for RRT.

DESIGN

Single-center, prospective, observational study.

SETTING

University Hospital of Muenster, Germany.

PATIENTS

Critically ill, postoperative patients with moderate AKI (Kidney Disease: Improving Global Outcomes stage 2) and risk factors for further progression (vasopressors and/or mechanical ventilation) receiving an FST.

INTERVENTIONS

Sample collection and measurement of different biomarkers (chemokine [C-C motif] ligand 14 [CCL14], neutrophil gelatinase-associated lipocalin, dipeptidyl peptidase 3).

MEASUREMENT AND MAIN RESULTS

The primary endpoint was the development of greater than or equal to one predefined RRT indications (hyperkalemia [≥ 6 mmol/L], diuretic-resistant hypervolemia, high urea serum levels [≥ 150 mg/dL], severe metabolic acidosis [pH ≤ 7.15], oliguria [urinary output < 200 mL/12 hr], or anuria). Two hundred eight patients were available for the primary analysis with 108 having a negative FST (urine output < 200 mL in 2 hr following FST). Ninety-eight patients (47%) met the primary endpoint, 82% in the FST negative cohort. At the time of inclusion, the combination of a negative FST test and high urinary CCL14 levels had a significantly higher predictive value for the primary endpoint with an area under the receiver operating characteristic curve (AUC) of 0.87 (95% CI, 0.82-0.92) compared with FST or CCL14 alone (AUC, 0.79; 95% CI, 0.74-0.85 and AUC, 0.83; 95% CI, 0.77-0.89; p < 0.001, respectively). Other biomarkers showed lower AUCs.

CONCLUSIONS

The combination of the FST with the renal biomarker CCL14 predicts the development of indications for RRT.

Rationale and Design of NEUTRALIZE-AKI: A Multicenter, Randomized, Controlled, Pivotal Study to Assess the Safety and Efficacy of a Selective Cytopheretic Device in Patients with Acute Kidney Injury Requiring Continuous Kidney Replacement Therapy

INTRODUCTION

NEUTRALIZE-AKI is a pivotal study to evaluate the safety and effectiveness of the selective cytopheretic device (SCD) in adult patients with acute kidney injury (AKI) requiring continuous kidney replacement therapy (CKRT).

METHODS/DESIGN

This is a two-arm, randomized, open-label, controlled multi-center pivotal US study which will enroll 200 adult patients (age 18-80 years) in the intensive care unit with acute kidney injury requiring CKRT and at least one additional organ failure across 30 clinical centers. Eligible patients will be randomized to CKRT plus SCD therapy versus CKRT alone. Therapy will be administered for up to 10 days, with the hypothesis that the CKRT plus SCD group will demonstrate a lower mortality rate or better rate of renal recovery than the CKRT alone group by day 90. The primary outcome is a composite of dialysis dependence or all-cause mortality at day 90.

CONCLUSION

The SCD is a cell-directed extracorporeal therapy that targets and deactivates pro-inflammatory neutrophils and monocytes, with evidence of efficacy across a variety of critically ill patient populations. Knowledge and experience from many of those studies and other AKI trials were incorporated into the design of this pivotal study, with the aim to investigate the role of effector cell immunomodulation in the intervention of AKI.

HMGB1 Is a Prognostic Factor for Mortality in Acute Kidney Injury Requiring Renal Replacement Therapy

INSTRUCTION

High mobility group box 1 (HMGB1) is a pro-inflammatory cytokine that reportedly causes kidney injury and other organ damage in rodent acute kidney injury (AKI) models. However, it remains unclear whether HMGB1 is associated with clinical AKI and related outcomes. This study aimed to evaluate the association with HMGB1 and prognosis of AKI requiring continuous renal replacement therapy (CRRT).

METHODS

AKI patients treated with CRRT in our intensive care unit were enrolled consecutively during 2013-2016. Plasma HMGB1 was measured on initiation. Classic initiation was defined as presenting at least one of the following conventional indications: hyperkalemia (K ≥6.5 mEq/L), severe acidosis (pH <7.15), uremia (UN >100 mg/dL), and diuretics-resistant pulmonary edema. Early initiation was defined as presenting no conventional indications. The primary outcome was defined as 90-day mortality.

RESULTS

A total of 177 AKI patients were enrolled in this study. HMGB1 was significantly associated with the primary outcome (hazard ratio, 1.06; 95% CI, 1.04-1.08). When the patients were divided into two-by-two groups by the timing of CRRT initiation and the HMBG1 cutoff value obtained by receiver operating curve (ROC) analysis, the high HMGB1 group (>10 ng/mL) with classic initiation was significantly associated with the primary outcome compared with the others, even after adjusting for other factors including the nonrenal serial organ failure assessment (SOFA) score.

CONCLUSION

HMGB1 was associated with 90-day mortality in AKI patients requiring CRRT. Notably, the highest mortality was observed in the high HMGB1 group with classic initiation. These findings suggest that CRRT should be considered for AKI patients with high HMGB1, regardless of the conventional indications.

Fluid Therapy for Critically Ill Adults With Sepsis: A Review

Importance

Approximately 20% to 30% of patients admitted to an intensive care unit have sepsis. While fluid therapy typically begins in the emergency department, intravenous fluids in the intensive care unit are an essential component of therapy for sepsis.

Observations

For patients with sepsis, intravenous fluid can increase cardiac output and blood pressure, maintain or increase intravascular fluid volume, and deliver medications. Fluid therapy can be conceptualized as 4 overlapping phases from early illness through resolution of sepsis: resuscitation (rapid fluid administered to restore perfusion); optimization (the risks and benefits of additional fluids to treat shock and ensure organ perfusion are evaluated); stabilization (fluid therapy is used only when there is a signal of fluid responsiveness); and evacuation (excess fluid accumulated during treatment of critical illness is eliminated). Among 3723 patients with sepsis who received 1 to 2 L of fluid, 3 randomized clinical trials (RCTs) reported that goal-directed therapy administering fluid boluses to attain a central venous pressure of 8 to 12 mm Hg, vasopressors to attain a mean arterial blood pressure of 65 to 90 mm Hg, and red blood cell transfusions or inotropes to attain a central venous oxygen saturation of at least 70% did not decrease mortality compared with unstructured clinical care (24.9% vs 25.4%; P = .68). Among 1563 patients with sepsis and hypotension who received 1 L of fluid, an RCT reported that favoring vasopressor treatment did not improve mortality compared with further fluid administration (14.0% vs 14.9%; P = .61). Another RCT reported that among 1554 patients in the intensive care unit with septic shock treated with at least 1 L of fluid compared with more liberal fluid administration, restricting fluid administration in the absence of severe hypoperfusion did not reduce mortality (42.3% vs 42.1%; P = .96). An RCT of 1000 patients with acute respiratory distress during the evacuation phase reported that limiting fluid administration and administering diuretics improved the number of days alive without mechanical ventilation compared with fluid treatment to attain higher intracardiac pressure (14.6 vs 12.1 days; P < .001), and it reported that hydroxyethyl starch significantly increased the incidence of kidney replacement therapy compared with saline (7.0% vs 5.8%; P = .04), Ringer lactate, or Ringer acetate.

Conclusions and Relevance

Fluids are an important component of treating patients who are critically ill with sepsis. Although optimal fluid management in patients with sepsis remains uncertain, clinicians should consider the risks and benefits of fluid administration in each phase of critical illness, avoid use of hydroxyethyl starch, and facilitate fluid removal for patients recovering from acute respiratory distress syndrome.

Volume Management with Kidney Replacement Therapy in the Critically Ill Patient

While the administration of intravenous fluids remains an important treatment, the negative consequences of subsequent fluid overload have raised questions about when and how clinicians should pursue avenues of fluid removal. Decisions regarding fluid removal during critical illness are complex even for patients with preserved kidney function. This article seeks to apply general concepts of fluid management to the care of patients who also require KRT. Because optimal fluid management for any specific patient is likely to change over the course of critical illness, conceptual models using phases of care have been developed. In this review, we will examine the implications of one such model on the use of ultrafiltration during KRT for volume removal in distributive shock. This will also provide a useful lens to re-examine published data of KRT during critical illness. We will highlight recent prospective trials of KRT as well as recent retrospective studies examining ultrafiltration rate and mortality, review the results, and discuss applications and shortcomings of these studies. We also emphasize that current data and techniques suggest that optimal guidelines will not consist of recommendations for or against absolute fluid removal rates but will instead require the development of dynamic protocols involving frequent cycles of reassessment and adjustment of net fluid removal goals. If optimal fluid management is dynamic, then frequent assessment of fluid responsiveness, fluid toxicity, and tolerance of fluid removal will be needed. Innovations in our ability to assess these parameters may improve our management of ultrafiltration in the future.

Assessment of severity scoring systems for predicting mortality in critically ill patients receiving continuous renal replacement therapy

The incidence of acute kidney injury (AKI) is increasing every year and many patients with AKI admitted to the intensive care unit (ICU) require continuous renal replacement therapy (CRRT). This study compared and analyzed severity scoring systems to assess their suitability in predicting mortality in critically ill patients receiving CRRT. Data from 612 patients receiving CRRT in four ICUs of the Korea University Medical Center between January 2016 and November 2018 were retrospectively collected. The mean age of all patients was 67.6 ± 14.8 years, and the proportion of males was 59.6%. The endpoints were in-hospital mortality and 7-day mortality from the day of CRRT initiation to the date of death. The Program to Improve Care in Acute Renal Disease (PICARD), Demirjian's, Acute Physiology and Chronic Health Evaluation (APACHE) II, Simplified Acute Physiology Score (SAPS) 3, Sequential Organ Failure Assessment (SOFA), Multiple Organ Dysfunction Score (MODS), and Liano's scores were used to predict mortality. The in-hospital and 7-day mortality rates in the study population were 72.7% and 45.1%, respectively. The area under the receiver operator characteristic curve (AUROC) revealed the highest discrimination ability for Demirjian's score (0.770), followed by Liano's score (0.728) and APACHE II (0.710). The AUROC curves for the SAPS 3, MODS, and PICARD were 0.671, 0.665, and 0.658, respectively. The AUROC of Demirjian's score was significantly higher than that of the other scores, except for Liano's score. The Hosmer-Lemeshow test on Demirjian's score showed a poor fit in our analysis; however, it was more acceptable than general severity scores. Kidney-specific severity scoring systems showed better performance in predicting mortality in critically ill patients receiving CRRT than general severity scoring systems.

Management of renal replacement therapy among adults in French intensive care units: A bedside practice evaluation

Background

This study aimed to investigate renal replacement therapy (RRT) practices in a representative nationwide sample of French intensive care units (ICUs).

Methods

From July 1 to October 5 2021, 67 French ICUs provided data regarding their ICU and RRT implementation. We used an online questionnaire to record general data about each participating ICU, including the type of hospital, number of beds, staff ratios, and RRT implementation. Each center then prospectively recorded RRT parameters from 5 consecutive acute kidney injury (AKI) patients, namely the indication, type of dialysis catheter used, type of catheter lock used, type of RRT (continuous or intermittent), the RRT parameters initially prescribed (dose, blood flow, and duration), and the anticoagulant agent used for the circuit.

Results

A total of 303 patients from 67 ICUs were analyzed. Main indications for RRT were oligo-anuria (57.4%), metabolic acidosis (52.1%), and increased plasma urea levels (47.9%). The commonest insertion site was the right internal jugular (45.2%). In 71.0% of cases, the dialysis catheter was inserted by a resident. Ultrasound guidance was used in 97.0% and isovolumic connection in 90.1%. Citrate, unfractionated heparin, and saline were used as catheter locks in 46.9%, 24.1%, and 21.1% of cases, respectively.

Conclusions

Practices in French ICUs are largely compliant with current national guidelines and international literature. The findings should be interpreted in light of the limitations inherent to this type of study.