Current state of the art for renal replacement therapy in critically ill patients with acute kidney injury

Assessment of urine CCL2 as a potential diagnostic biomarker for acute kidney injury and septic acute kidney injury in intensive care unit patients

Acute kidney injury (AKI) is a prevalent and serious condition in the intensive care unit (ICU), associated with significant morbidity and mortality. Septic acute kidney injury (SAKI) contributes substantially to AKI cases in the ICU. However, current diagnostic methods have limitations, necessitating the exploration of novel biomarkers. In this study, we investigated the potential of plasma and urine CCL2 levels as diagnostic markers for AKI and SAKI in 216 ICU patients. Our findings revealed significant differences in plasma (p < 0.01) and urine CCL2 (p < 0.0001) levels between AKI and non-AKI patients in the ICU. Notably, urine CCL2 demonstrated promising predictive value for AKI, exhibiting high specificity and sensitivity (AUC = 0.8976; p < 0.0001). Furthermore, we observed higher urine CCL2 levels in SAKI compared to non-septic AKI (p < 0.001) and urine CCL2 could also differentiate SAKI from non-septic AKI (AUC = 0.7597; p < 0.0001). These results suggest that urine CCL2 levels hold promise as early biomarkers for AKI and SAKI, offering valuable insights for timely intervention and improved management of ICU patients.

Clinical Characteristics and the Prognostic Impact of Acute Kidney Injury in Critically Ill Patients with Invasive Pulmonary Aspergillosis in the Intensive Care Unit: A Retrospective, Single-Center Study

Introduction

The incidence and impact of acute kidney injury (AKI) in patients with invasive pulmonary aspergillosis (IPA) admitted to the intensive care unit (ICU) are unknown.

Methods

This retrospective study included 140 patients who were diagnosed with IPA and admitted to the medical ICU of China-Japan Friendship Hospital in Beijing, China. AKI was defined according to the Kidney Disease: Improving Global Outcomes guidelines. Data on demographic characteristics, comorbidities, laboratory tests, treatments, and prognosis at ICU admission were collected.

Results

The rate of AKI was 71.4% (n = 100), and approximately 30% of the patients had preadmission acute kidney dysfunction. Of the 100 patients with AKI, 19, 8, and 73 patients had stage I, II, and III AKI, respectively, and 64 (87.6%) patients required continuous renal replacement therapy. Overall ICU mortality rate was 52.1%. Irreversible AKI was a strong independent risk factor for ICU mortality (odds ratio 13.36, 95% confidence interval 4.52-39.48, p < 0.001), followed by chronic lung disease, use of intermittent positive-pressure ventilation, and long-term corticosteroid treatment within 1 year prior to ICU admission. Higher cardiac troponin I levels at admission and worse volume control during the first 7 days of ICU stay were potential predictive factors of irreversible kidney dysfunction. Patients with irreversible AKI and those who died during the ICU stay had greater volume overload during the first 14 days of ICU stay. Patients who survived received earlier renal replacement therapy support after ICU admission compared to those who died (median, 2 vs. 5 days; p = 0.026).

Conclusion

Compared to the patients with IPA in the absence of AKI, those with AKI presented with more volume overload, worse disease burden, and required stronger respiratory support, while experiencing worse prognosis. Irreversible AKI was a strong predictor of mortality in patients with critical IPA. Better volume control and earlier CRRT initiation should be considered key points in AKI management and prognostic improvement.

Initial renal replacement therapy (RRT) modality associates with 90-day postdischarge RRT dependence in critically ill AKI survivors

PURPOSE

Real-world comparison of RRT modality on RRT dependence at 90 days postdischarge among ICU patients discharged alive after RRT for acute kidney injury (AKI).

METHODS

Using claims-linked to US hospital discharge data (Premier PINC AI Healthcare Database [PHD]), we compared continuous renal replacement therapy (CRRT) vs. intermittent hemodialysis (IHD) for AKI in adult ICU patients discharged alive from January 1, 2018 to June 30, 2021. RRT dependence at 90 days postdischarge was defined as ≥2 RRT treatments in the last 8 days. Between-group differences were balanced using inverse probability treatment weighting (IPTW).

RESULTS

Of 34,804 patients, 3804 patients (from 382 hospitals) had claims coverage for days 83-90 postdischarge. Compared to IHD-treated patients (n = 2740), CRRT-treated patients (n = 1064) were younger; had more admission to large teaching hospitals, surgery, sepsis, shock, mechanical ventilation, but lower prevalence of comorbidities (p < 0.05 for all). Compared to IHD-treated patients, CRRT-treated patients had lower RRT dependence at hospital discharge (26.5% vs. 29.8%, p = 0.04) and lower RRT dependence at 90 days postdischarge (4.9% vs. 7.4% p = 0.006) with weighted adjusted OR (95% CI): 0.68 (0.47-0.97), p = 0.03. Results persisted in sensitivity analyses including patients who died during days 1-90 postdischarge (n = 112) or excluding patients from hospitals with IHD patients only (n = 335), or when excluding patients who switched RRT modalities (n = 451).

CONCLUSIONS

Adjusted for potential confounders, the odds of RRT dependence at 90 days postdischarge among survivors of RRT for AKI was 30% lower for those treated first with CRRT vs. IHD, overall and in several sensitivity analyses.

SUMMARY

Critically ill patients in intensive care units (ICU) may develop acute kidney injury (AKI) that requires renal replacement therapy (RRT) to temporarily replace the injured kidney function of cleaning the blood. Two main types of RRT in the ICU are called continuous renal replacement therapy (CRRT), which is performed almost continuously, i.e., for >18 h per day, and intermittent hemodialysis (IHD), which is a more rapid RRT that is usually completed in a little bit over 6 h, several times per week. The slower CRRT may be gentler on the kidneys and is more likely to be used in the sickest patients, who may not be able to tolerate IHD. We conducted a data-analysis study to evaluate whether long-term effects on kidney function (assessed by ongoing need for RRT, i.e., RRT dependence) differ depending on use of CRRT vs. IHD. In a very large US linked hospital-discharge/claims database we found that among ICU patients discharge alive after RRT for AKI, fewer CRRT-treated patients had RRT dependence at hospital discharge (26.5% vs. 29.8%, p = 0.04) and at 90 days after discharge (4.9% vs. 7.4% p = 0.006). In adjusted models, RRT dependence at 90 days postdischarge was >30% lower for CRRT than IHD-treated patients. These results from a non-randomized study suggest that among survivors of RRT for AKI, CRRT may result in less RRT dependence 90 days after hospital discharge.

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.

Huangqi Jiuni decoction prevents acute kidney injury induced by severe burns by inhibiting activation of the TNF/NF-κB pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Huangqi Jiuni decoction (HQJND) is a prescription for the treatment of severe burns provided based on traditional Chinese and Western medicine, which is created by the First Affiliated Hospital of Anhui Medical University. It consists of 12 herbs and has been used clinically for decades. It has greatly shortened the course of the disease, but the mechanism by which HQJND treats the disease still remains unclear.

AIM OF THE STUDY

Hence, the objective of this investigation was to utilize modern pharmacological tools to demonstrate the efficacy and mechanism of HQJND in the treatment of acute kidney injury (AKI) caused by severe burns.

MATERIALS AND METHODS

In this study, the chemical constituents in HQJND were first examined using liquid chromatography tandem mass spectrometry (LC-MS/MS). Then, by using network pharmacology, we screened the targets of drug and disease action, and predicted the signaling pathways acting in the course of drug treatment of disease. Finally, we attempted to verify the efficacy of the drug and explored its therapeutic mechanism after the establishment of an animal model, herbal gavage treatment, collection of rat kidneys and serum for renal function, quantitative real-time Polymerase Chain Reaction (RT-qPCR), Western Blotting (WB), Hematoxylin and eosin (HE) staining and Immunohistochemistry (IHC).

RESULTS

The 14 important active ingredients in HQJND was analyzed by liquid chromatography tandem mass spectrometry, while network pharmacology screening was performed to identify 353 disease-associated marker genes and 286 drug targets, finally identifying the TNF/NF-κB (tumor necrosis factor/nuclear factor kappa-B) signaling site: the key pathway of burn-induced acute kidney injury when HQJND intervened. The serum renal function and histopathology of rats demonstrated that the use of HQJND significantly improved the renal function in severe burns. RT-qPCR and WB confirmed that the TNF/NF-κB signaling pathway was activated in the Model group of rats, and HQJND could curb the signaling pathway because it moderated the expressions of key proteins in the process.

CONCLUSION

Based on modern pharmacology, we explored an effective herbal preparation to ameliorate the impairment of renal function after severe burns, which is most likely to function through the TNF/NF-κB signaling pathway.

Septic shock and biliary sepsis: 90-day mortality and associated risk factors

BACKGROUND

Biliary sepsis is common in patients with digestive cancer. Recommendations call for antibiotic de-escalation (ADE) as a strategy for antibiotic treatment of sepsis or septic shock. The aim of this study was to identify factors influencing 90-day mortality and to evaluate the impact of ADE.

METHODS

This retrospective study was conducted between November 2008 and December 2019 in a referral cancer center. Adults with biliary sepsis or septic shock admitted to the ICU were included. Variables associated with 90-day mortality were identified using univariate and multivariate Cox proportional hazards models.

RESULTS

122 patients were included. The 90-day mortality was 30.3% (n = 37). After multivariate analysis, the factors independently associated 90-day mortality were metastatic stage (p = 0.004), biliary tract tumour compression (p = 0.001), multi drug resistant (MDR) bacteria carriage on intensive care unit (ICU)admission (p = 0.048), serum lactate on ICU admission (p < 0.001), the use of extra-renal replacement (p = 0.008), factor V < 50% (p = 0.009) and performance status (ECOG-PS) > 2 (p < 0.001). ADE of the pivotal antibiotic (p = 0.041) and recent cancer surgery (p < 0.001) appeared to be associated with survival.

CONCLUSION

The 90-day mortality of biliary sepsis seems to be favourable. The 90-day mortality is associated with organ dysfunctions, but also with ECOG-PS, cancer stage, MDR bacteria colonisation. ADE seems to be safe.

Vancomycin removal and pharmacokinetics during accelerated venovenous hemofiltration

INTRODUCTION

Vancomycin pharmacokinetics are affected by renal replacement therapy and physiologic changes in critically ill patients. Literature regarding vancomycin removal and pharmacokinetics during accelerated venovenous hemofiltration (AVVH), a form of prolonged intermittent renal replacement therapy, is limited.

OBJECTIVE

To describe the removal and pharmacokinetics of vancomycin during AVVH.

METHODS

Eighteen critically ill adults receiving vancomycin and AVVH were included. Vancomycin serum concentrations were obtained within 4 h before and 2-6 h after the AVVH session. Patients' serum concentrations were plotted against time, and individual pharmacokinetic parameters were determined by a one-compartmental analysis. Continuous data are reported as a median (interquartile range [IQR]) and categorical data as a percentage.

RESULTS

The median AVVH effluent rate was 39.3 mL/kg/h (IQR 35.5-48 mL/kg/h) for a duration of 9 h (IQR 8-9.75 h). AVVH decreased vancomycin concentrations by 29.8% (IQR 24.9%-35.9%), at a rate of 3.4% per hour (IQR 3.1%-4.3% per hour) of AVVH. The vancomycin elimination rate constant and half-life were 0.039 h-1 (IQR 0.036-0.053 h-1 ) and 17.6 h (IQR 13.1-18.8 h), respectively. The area under the curve during AVVH was 171.7 mg*h/L (IQR 149.1-190 mg*h/L). The volume of distribution in 10 patients was 1 L/kg (IQR 0.73-1.1 L/kg). After AVVH, vancomycin 1000 mg (IQR 750-1000 mg) was needed to maintain a serum trough concentration ≥15 mg/L.

CONCLUSION

Vancomycin is significantly removed by AVVH, which requires supplemental dosing after completion of the AVVH session to maintain desired serum concentrations. Therapeutic drug monitoring of vancomycin serum concentrations is recommended for patients undergoing AVVH.

Prognostic role of renal replacement therapy among hospitalized patients with heart failure in the Brazilian national public health system

Introduction

Data on patients hospitalized with acute heart failure in Brazil scarce.

Methods

We performed a cross-sectional, retrospective, records-based study using data retrieved from a large public database of heart failure admissions to any hospital from the Brazilian National Public Health System (SUS) (SUS Hospital Information System [SIHSUS] registry) to determine the in-hospital all-cause mortality rate, in-hospital renal replacement therapy rate and its association with outcome.

Results

In total, 910,128 hospitalizations due to heart failure were identified in the SIHSUS registry between April 2017 and August 2021, of which 106,383 (11.7%) resulted in in-hospital death. Renal replacement therapy (required by 8,179 non-survivors [7.7%] and 11,496 survivors [1.4%, p < 0.001]) was associated with a 56% increase in the risk of death in the univariate regression model (HR 1.56, 95% CI 1.52 -1.59), a more than threefold increase of the duration of hospitalization, and a 45% or greater increase of cost per day. All forms of renal replacement therapy remained independently associated with in-hospital mortality in multivariable analysis (intermittent hemodialysis: HR 1.64, 95% CI 1.60 -1.69; continuous hemodialysis: HR 1.52, 95% CI 1.42 -1.63; peritoneal dialysis: HR 1.47, 95% CI 1.20 -1.88).

Discussion

The in-hospital mortality rate of 11.7% observed among patients with acute heart failure admitted to Brazilian public hospitals was alarmingly high, exceeding that of patients admitted to North American and European institutions. This is the first report to quantify the rate of renal replacement therapy in patients hospitalized with acute heart failure in Brazil.

Initial 24-h perfusion index of ICU admission is associated with acute kidney injury in perioperative critically ill patients: A retrospective cohort analysis

Background

The relationship between perfusion index (PI) and organ dysfunction in patients in the intensive care unit (ICU) is not clear. This study aimed to explore the relationship between PI and renal function in the perioperative critical care setting and evaluate the predictive efficiency of PI on patients with acute kidney injury (AKI) in the ICU.

Methods

This retrospective analysis involved 12,979 patients who had undergone an operation and were admitted to the ICU in Peking Union Medical College Hospital from January 2014 to December 2019. The distribution of average PI in the first 24 h after ICU admission and its correlation with AKI was calculated by Cox regression. Receiver operating characteristic (ROC) curves were generated to compare the ability of PI, mean arterial pressure (MAP), creatinine, blood urea nitrogen (BUN), and central venous pressure (CVP) to discriminate AKI in the first 48 h in all perioperative critically ill patients.

Results

Average PI in the first 24 h served as an independent protective factor of AKI (Odds ratio [OR]=0.786, 95% confidence interval [CI]: 0.704-0.873, P <0.0001). With a decrease in PI by one unit, the incidence of AKI increased 1.74 times. Among the variables explored for the prediction of AKI (PI, MAP, creatine, BUN, and CVP), PI yielded the highest area under the ROC curve, with a sensitivity of 64.34% and specificity of 70.14%. A cut-off value of PI ≤2.12 could be used to predict AKI according to the Youden index. Moreover, patients in the low PI group (PI ≤2.12) exhibited a marked creatine elevation at 24-48 h with a slower decrease compared with those in the high PI group (PI >2.12).

Conclusions

As a local blood flow indicator, the initial 24-h average PI for perioperative critically ill patients can predict AKI during their first 120 h in the ICU.

Predictive Models for Kidney Recovery and Death in Patients Continuing Dialysis as Outpatients after Starting in Hospital

BACKGROUND

For patients who initiate dialysis during a hospital admission and continue to require dialysis after discharge, outpatient dialysis management could be improved by better understanding the future likelihood of recovery to dialysis independence and the competing risk of death.

METHODS

We derived and validated linked models to predict the subsequent recovery to dialysis independence and death within 1 year of hospital discharge using a population-based cohort of 7657 patients in Ontario, Canada. Predictive variables included age, comorbidities, length of hospital admission, intensive care status, discharge disposition, and prehospital admission eGFR and random urine albumin-to-creatinine ratio. Models were externally validated in 1503 contemporaneous patients from Alberta, Canada. Both models were created using proportional hazards survival analysis, with the "Recovery Model" using Fine-Gray methods. Probabilities generated from both models were used to develop 16 distinct "Recovery and Death in Outpatients" (ReDO) risk groups.

RESULTS

ReDO risk groups in the derivation group had significantly distinct 1-year probabilities for recovery to dialysis independence (first quartile: 10% [95% confidence interval (CI), 9% to 11%]; fourth quartile: 73% [70% to 77%]) and for death (first quartile: 12% [11% to 13%]; fourth quartile: 46% [43% to 50%]). In the validation group, model discrimination was modest (c-statistics [95% CI] for recovery and for death quartiles were 0.70 [0.67 to 0.73] and 0.66 [0.62 to 0.69], respectively), but calibration was excellent (integrated calibration index [95% CI] was 7% [5% to 9%] and 4% [2% to 6%] for recovery and death, respectively).

CONCLUSIONS

The ReDO models generated accurate expected probabilities of recovery to dialysis independence and death in patients who continued outpatient dialysis after initiating dialysis in hospital. An online tool on the basis of the models is available at https://qxmd.com/calculate/calculator_874 .

Debate: Intermittent Hemodialysis versus Continuous Kidney Replacement Therapy in the Critically Ill Patient: The Argument for CKRT

Continuous kidney replacement therapy (CKRT) is well entrenched as one of the dominant KRT modalities in modern critical care practice. Since its introduction four decades ago, there have been considerable innovations in CKRT machines that have improved precision, safety, and simplicity. CKRT is the preferred KRT modality for critically ill patients with hemodynamic instability. Early physical therapy and rehabilitation can be feasibly and safely provided to patients connected to CKRT, thus obviating concerns about immobility. Although randomized clinical trials have not shown a mortality difference when comparing CKRT and intermittent hemodialysis, CKRT allows precision delivery of solute and fluid removal that can be readily adjusted in the face of dynamic circumstances. Accumulated evidence from observational studies, although susceptible to bias, has shown that CKRT, when compared with intermittent hemodialysis, is associated with better short- and long-term kidney recovery and KRT independence. Critical care medicine encompasses a wide range of sick patients, and no single KRT modality is likely to ideally suit every patient in every context and for every condition. The provision of KRT represents a spectrum of modalities to which patients can flexibly transition in response to their evolving condition. As a vital tool for organ support in the intensive care unit, CKRT enables the personalization of KRT to meet the clinical demands of patients during the most severe phases of their illness.

Debate: Intermittent Hemodialysis versus Continuous Kidney Replacement Therapy in the Critically Ill Patient: The Choice Should Be Evidence Based

Kidney replacement therapy (KRT) plays a major role in the treatment of severe AKI. Intermittent hemodialysis (HD) and continuous KRT (CKRT) are the main modalities in critically ill patients with AKI. CKRT is the preferred modality in many countries because of its alleged superiority on both hemodynamic tolerance and on kidney function recovery. In fact, randomized controlled trials (RCTs) comparing the two modalities have not shown any actual benefit of one technique over the other on mortality, hemodynamics, or kidney function recovery. Those RCTs were conducted more than 15 years ago. Major progress was eventually made leading to much lower mortality rates in recent studies than in previous studies. In addition, those RCTs included a noticeable proportion of patients who could have recovered without ever receiving KRT, as demonstrated by several recent studies. In the absence of evidence of clinical superiority of one KRT modality, the choice must be addressed not only regarding clinical outcome but also resources and logistics. Conclusions of health technology assessments and study reports were heterogeneous and conflicting concerning cost-effectiveness of intermittent HD versus CKRT. All these considerations justify a reevaluation of the issue in new RCTs that take into account recent knowledge on KRT initiation and management. Pending results of such study, the choice should be guided mainly by organizational considerations in each unit and without condemning any modality in the absence of proof.

GDF11 Improves Ischemia-Reperfusion-Induced Acute Kidney Injury via Regulating Macrophage M1/M2 Polarization

INTRODUCTION

Acute kidney injury (AKI) is a clinical emergency caused by the rapid decline of renal function caused by various etiologies. Growth differentiation factor 11 (GDF11) can promote renal tubular regeneration and improve kidney function in AKI, but the specific mechanism remains unclear. Herein, we investigated the effect and mechanisms of GDF11 in ameliorating AKI induced by ischemia-reperfusion (I/R).

METHODS

An animal model of AKI was established by I/R method, and the changes of serum urea nitrogen and creatinine were measured to evaluate the AKI. Enzyme-linked immunosorbent assay (ELISA) was used to measure cytokines, malondialdehyde, superoxide dismutase, nitric oxide synthase, and arginase 1 levels. Flow cytometry was used to count the M1/M2 macrophages. IHC, WB, and q-PCR experiments were used to evaluate the expression of GDF11.

RESULTS

The changes in serum levels of urea nitrogen and creatinine after I/R suggest that an animal model of AKI induced by I/R was successfully established. AKI caused by I/R significantly changed the M1/M2 macrophage polarization balance, with an increase in M2 being significantly higher than M1 as well as increased oxidative stress. Treatment with GDF11 after I/R significantly increased the differentiation of M2 cells and inhibited the differentiation of M1 macrophages, as well as decreased oxidative stress.

CONCLUSION

GDF11 can promote the repair of AKI caused by I/R by regulating the balance of M1/M2 polarization in macrophages and oxidative stress.

Management of Intermittent Hemodialysis in the Critically Ill Patient

Intermittent hemodialysis remains a cornerstone of extracorporeal KRT in the intensive care unit, either as a first-line therapy for AKI or a second-line therapy when patients transition from a continuous or prolonged intermittent therapy. Intermittent hemodialysis is usually provided 3 days per week in this setting on the basis that no clinical benefits have been demonstrated with more frequent hemodialysis. This should not detract from the importance of continually assessing and refining the hemodialysis prescription (including the need for extra treatments) according to dynamic changes in extracellular volume and other parameters, and ensuring that an adequate dose of hemodialysis is being delivered to the patient. Compared with other KRT modalities, the cardinal challenge encountered during intermittent hemodialysis is hemodynamic instability. This phenomenon occurs when reductions in intravascular volume, as a consequence of ultrafiltration and/or osmotic shifts, outpace compensatory plasma refilling from the extravascular space. Myocardial stunning, triggered by intermittent hemodialysis, and independent of ultrafiltration, may also contribute. The hemodynamic effect of intermittent hemodialysis is likely magnified in patients who are critically ill due to an inability to mount sufficient compensatory physiologic responses in the context of multiorgan dysfunction. Of the many interventions that have undergone testing to mitigate hemodynamic instability related to KRT, the best evidence exists for cooling the dialysate and raising the dialysate sodium concentration. Unfortunately, the evidence supporting routine use of these and other interventions is weak owing to poor study quality and limited sample sizes. Intermittent hemodialysis will continue to be an important and commonly used KRT modality for AKI in patients with critical illness, especially in jurisdictions where resources are limited. There is an urgent need to harmonize the definition of hemodynamic instability related to KRT in clinical trials and robustly test strategies to combat it in this vulnerable patient population.

A retrospective analysis: the outcome of renal replacement therapies in critically ill children

OBJECTIVE

A few pediatric studies were present which focused on renal replacement therapy used for critically ill children. This research aimed to determine the ratio of utilization of intermittent hemodialysis, continuous renal replacement therapy, and peritoneal dialysis, and to study the properties and outcomes of critically ill pediatric patients who underwent renal replacement therapy.

METHODS

Critically ill children admitted to the intensive care unit and received renal replacement therapy from February 2020 to May 2022 were included. The children were divided into three groups: hemodialysis, continuous renal replacement therapy, and peritoneal dialysis.

RESULTS

A total of 37 patients (22 boys and 15 girls) who received renal replacement therapy met the criteria for this study. Continuous renal replacement therapy was used in 43%, hemodialysis in 38%, and peritoneal dialysis in 19%. In all, 28 (73%) children survived and 9 (27%) died in intensive care unit. The mean systolic blood pressure was significantly lower among children who received continuous renal replacement therapy (p<0.001). The need for inotropic medications and a higher PRISM III score were found to be the greatest indicators of mortality.

CONCLUSION

The outcome of children receiving renal replacement therapy seems to be related to their needs for vasoactive drugs and the severity of the underlying disease in the continuous renal replacement therapy group relative to the other groups.

Indications for and Timing of Initiation of KRT

KRT is considered for patients with severe AKI and associated complications. The exact indications for initiating KRT have been debated for decades. There is a general consensus that KRT should be considered in patients with AKI and medically refractory complications ("urgent indications"). "Relative indications" are more common but defined with less precision. In this review, we summarize the latest evidence from recent landmark clinical trials, discuss strategies to anticipate the need for KRT in individual patients, and propose an algorithm for decision making. We emphasize that the decision to consider KRT should be made in conjunction with other forms of organ support therapies and important nonkidney factors, including the patient's preferences and overall goals of care. We also suggest future research to differentiate patients who benefit from timely initiation of KRT from those with imminent recovery of kidney function. Until then, efforts are needed to optimize the initiation and delivery of KRT in routine clinical practice, to minimize nonessential variation, and to ensure that patients with persistent AKI or progressive organ failure affected by AKI receive KRT in a timely manner.

Predicting mortality in acute kidney injury patients undergoing continuous renal replacement therapy using a visualization model: A retrospective study

Background: Patients with severe acute kidney injury (AKI) require continuous renal replacement therapy (CRRT) when hemodynamically unstable. We aimed to identify prognostic factors and develop a nomogram that could predict mortality in patients with AKI undergoing CRRT. Methods: Data were extracted from the Dryad Digital Repository. We enrolled 1,002 participants and grouped them randomly into training (n = 670) and verification (n = 332) datasets based on a 2:1 proportion. Based on Cox proportional modeling of the training set, we created a web-based dynamic nomogram to estimate all-cause mortality. Results: The model incorporated phosphate, Charlson comorbidity index, body mass index, mean arterial pressure, levels of creatinine and albumin, and sequential organ failure assessment scores as independent predictive indicators. Model calibration and discrimination were satisfactory. In the training dataset, the area under the curves (AUCs) for estimating the 28-, 56-, and 84-day all-cause mortality were 0.779, 0.780, and 0.787, respectively. The model exhibited excellent calibration and discrimination in the validation dataset, with AUC values of 0.791, 0.778, and 0.806 for estimating 28-, 56-, and 84-day all-cause mortality, respectively. The calibration curves exhibited the consistency of the model between the two cohorts. To visualize the results, we created a web-based calculator. Conclusion: We created a web-based calculator for assessing fatality risk in patients with AKI receiving CRRT, which may help rationalize clinical decision-making and personalized therapy.

Accuracy of clinicians' ability to predict the need for renal replacement therapy: a prospective multicenter study

PURPOSE

Identifying patients who will receive renal replacement therapy (RRT) during intensive care unit (ICU) stay is a major challenge for intensivists. The objective of this study was to evaluate the performance of physicians in predicting the need for RRT at ICU admission and at acute kidney injury (AKI) diagnosis.

METHODS

Prospective, multicenter study including all adult patients hospitalized in 16 ICUs in October 2020. Physician prediction was estimated at ICU admission and at AKI diagnosis, according to a visual Likert scale. Discrimination, risk stratification and benefit of physician estimation were assessed. Mixed logistic regression models of variables associated with risk of receiving RRT, with and without physician estimation, were compared.

RESULTS

Six hundred and forty-nine patients were included, 270 (41.6%) developed AKI and 77 (11.8%) received RRT. At ICU admission and at AKI diagnosis, a model including physician prediction, the experience of the physician, SOFA score, serum creatinine and diuresis to determine need for RRT performed better than a model without physician estimation with an area under the ROC curve of 0.90 [95% CI 0.86-0.94, p < 0.008 (at ICU admission)] and 0.89 [95% CI 0.83-0.93, p = 0.0014 (at AKI diagnosis)]. In multivariate analysis, physician prediction was strongly associated with the need for RRT, independently of creatinine levels, diuresis, SOFA score and the experience of the doctor who made the prediction.

CONCLUSION

As physicians are able to stratify patients at high risk of RRT, physician judgement should be taken into account when designing new randomized studies focusing on RRT initiation during AKI.

Characteristics of and Outcomes After Dialysis-Treated Acute Kidney Injury, 2009-2018: A Taiwanese Multicenter Study

RATIONALE & OBJECTIVE

Dialysis-treated acute kidney injury (AKI) is increasingly common in intensive care units (ICUs) and is associated with poor outcomes. Few studies have explored the temporal trends in severity of acute illness at dialysis initiation, indications for dialysis, and their association with patient outcomes.

STUDY DESIGN

Multicenter retrospective cohort study.

SETTING & PARTICIPANTS

9,535 adult patients admitted to the ICU who received their first dialysis treatment from Chang Gung Memorial Hospital system in Taiwan from 2009 through 2018.

EXPOSURE

Calendar year.

OUTCOMES

ICU mortality and dialysis treatment at discharge among hospital survivors.

ANALYTICAL APPROACH

The temporal trends during the study period were investigated using test statistics suited for continuous or categorical data. The association between the study year and the risk of mortality was analyzed using multivariable Cox regression with adjustment for relevant clinical variables, including the severity of acute illness, defined by Sequential Organ Failure Assessment (SOFA) score.

RESULTS

The mean SOFA score at dialysis initiation decreased slightly from 14.0 in 2009 to 13.6 in 2018. There was no significant trend in the number of indications for dialysis initiation that were fulfilled over time. Observed ICU mortality decreased over time, and the curve appeared to be reverse J-shaped, with a substantial decrease from 56.1% in 2009 to 46.3% in 2015 and a slight increase afterward. The risk of mortality was significantly reduced from 2013 to 2018 compared with 2009 in adjusted models. The decreasing trend in ICU mortality over time remained significant. There was an increase in dialysis treatment at discharge among survivors, mainly in patients with estimated glomerular filtration rate<60mL/min/1.73m², from 36.8% in 2009 to 43.9% in 2018.

LIMITATIONS

Residual confounding from unmeasured factors over time such as severity of comorbidities, detailed medication interventions, and delivered dialysis dose.

CONCLUSIONS

We observed reductions in mortality among ICU patients with dialysis-treated acute kidney injury between 2009 and 2018, even after adjusting for dialysis indication and severity of illness at dialysis initiation. However, dialysis treatment at discharge among survivors has increased over time, mainly in patients with preexisting kidney disease.

Delivering optimal renal replacement therapy to critically ill patients with acute kidney injury

Critical illness is often complicated by acute kidney injury (AKI). In patients with severe AKI, renal replacement therapy (RRT) is deployed to address metabolic dysfunction and volume excess until kidney function recovers. This review is intended to provide a comprehensive update on key aspects of RRT prescription and delivery to critically ill patients. Recently completed trials have enhanced the evidence base regarding several RRT practices, most notably the timing of RRT initiation and anticoagulation for continuous therapies. Better evidence is still needed to clarify several aspects of care including optimal targets for ultrafiltration and effective strategies for RRT weaning and discontinuation.

Neutrophil gelatinase-associated lipocalin as predictor of acute kidney injury requiring renal replacement therapy: A systematic review and meta-analysis

Background

Patients with severe acute kidney injury (AKI) may require renal replacement therapy (RRT), such as hemodialysis and peritoneal dialysis. Neutrophil gelatinase-associated lipocalin (NGAL) is a sensitive indicator for early diagnosis and recognition of AKI; however, its predictive value of AKI-associated need for RRT needs further evaluation.

Methods

Following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines, relevant articles were systematically searched and selected from seven databases. The random effects model was applied to evaluate the predictive performance of NGAL for AKI requiring RRT. The Newcastle–Ottawa Scale (NOS) was used to assess the quality of each included study.

Results

A total of 18 studies including 1,787 patients with AKI and having an average NOS score of 7.67 were included in the meta-analysis. For plasma/serum NGAL, the pooled sensitivity and specificity with corresponding 95% confidence interval (CI) were 0.75 (95% CI: 0.68–0.81) and 0.76 (95% CI: 0.70–0.81), respectively. The pooled positive likelihood ratio (PLR) was 2.9 (95% CI: 2.1–4.1), and the pooled negative likelihood ratio (NLR) was 0.34 (95% CI: 0.25–0.46). Subsequently, the pooled diagnostic odds ratio (DOR) was 9 (95% CI: 5–16) using a random effects model, and the area under the curve (AUC) of summary receiver operating characteristic to summarize predictive accuracy was 0.82 (95% CI: 0.79–0.85). For urine NGAL, the pooled sensitivity, specificity, PLR, NLR, DOR, and AUC values were 0.78 (95% CI: 0.61–0.90), 0.77 (95% CI: 0.65–0.85), 3.4 (95% CI: 2.4–4.8), 0.28 (95% CI: 0.15–0.52), 12 (95% CI: 6–24), and 0.84 (95% CI: 0.80–0.87), respectively.

Conclusion

Plasma/serum and urine NGAL levels performed comparably well in predicting AKI requiring RRT. Our findings suggested that NGAL is an effective predictive biomarker for the AKI-associated need for RRT. Nevertheless, more pieces of high-quality evidence and future trials with larger sample sizes are needed for further improvement of patient outcomes.

Systematic review registration

[https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42022346595], identifier [CRD42022346595].

A Bayesian reanalysis of the Standard versus Accelerated Initiation of Renal-Replacement Therapy in Acute Kidney Injury (STARRT-AKI) trial

Background

Timing of initiation of kidney-replacement therapy (KRT) in critically ill patients remains controversial. The Standard versus Accelerated Initiation of Renal-Replacement Therapy in Acute Kidney Injury (STARRT-AKI) trial compared two strategies of KRT initiation (accelerated versus standard) in critically ill patients with acute kidney injury and found neutral results for 90-day all-cause mortality. Probabilistic exploration of the trial endpoints may enable greater understanding of the trial findings. We aimed to perform a reanalysis using a Bayesian framework.

Methods

We performed a secondary analysis of all 2927 patients randomized in multi-national STARRT-AKI trial, performed at 168 centers in 15 countries. The primary endpoint, 90-day all-cause mortality, was evaluated using hierarchical Bayesian logistic regression. A spectrum of priors includes optimistic, neutral, and pessimistic priors, along with priors informed from earlier clinical trials. Secondary endpoints (KRT-free days and hospital-free days) were assessed using zero–one inflated beta regression.

Results

The posterior probability of benefit comparing an accelerated versus a standard KRT initiation strategy for the primary endpoint suggested no important difference, regardless of the prior used (absolute difference of 0.13% [95% credible interval [CrI] − 3.30%; 3.40%], − 0.39% [95% CrI − 3.46%; 3.00%], and 0.64% [95% CrI − 2.53%; 3.88%] for neutral, optimistic, and pessimistic priors, respectively). There was a very low probability that the effect size was equal or larger than a consensus-defined minimal clinically important difference. Patients allocated to the accelerated strategy had a lower number of KRT-free days (median absolute difference of − 3.55 days [95% CrI − 6.38; − 0.48]), with a probability that the accelerated strategy was associated with more KRT-free days of 0.008. Hospital-free days were similar between strategies, with the accelerated strategy having a median absolute difference of 0.48 more hospital-free days (95% CrI − 1.87; 2.72) compared with the standard strategy and the probability that the accelerated strategy had more hospital-free days was 0.66.

Conclusions

In a Bayesian reanalysis of the STARRT-AKI trial, we found very low probability that an accelerated strategy has clinically important benefits compared with the standard strategy. Patients receiving the accelerated strategy probably have fewer days alive and KRT-free. These findings do not support the adoption of an accelerated strategy of KRT initiation.

Renal replacement therapy for acute kidney injury in burn patients, an international survey and a qualitative review of current controversies

BACKGROUND OF THE STUDY

Acute kidney injury (AKI) is a common complication in critically ill burn patients and is associated with a number of serious adverse outcomes. The clinical decision-making process related to the management of AKI in burn patients is complex and has not been sufficiently standardized. The main aim of this study was to explore the diagnostic approach and clinician's attitudes toward the management of AKI and RRT in burn patients around the world.

METHODS

The questionnaire was widely distributed among the members of International Society for Burn Injury (ISBI), who were invited to complete the survey. Data collection and report was compliant with the the Checklist for Reporting Results of Internet E-Surveys (CHERRIES) Web-survey guidelines. The survey form with multiple-choice questions was divided into 3 parts: a. physician and institutional demographics, b. AKI diagnostic information, c. technical aspects of RRT.

RESULTS

A total of 44 respondents worldwide submitted valuable data in the 2-month period. Of all respondents, 43.2% were from Europe, 30% from North America, 7% from South-East Asia 2.3% from Africa and 18.2% from other regions. 93.1% of participants declare that they use specific definitions to detect AKI, while 11.4% declare the use of renal ultrasonography for AKI diagnosis. CRRT appeared to be the most preferred option by 43.2% of participants, followed by intermittent hemodialysis (25%), and prolonged intermittent RRT (6.8%). The expertise to deliver a modality and the availability of resources were considered important factors when selecting the optimal RRT modality by 20.5% and 29.6% of respondents. The use of specific serum biomarkers for AKI diagnosis are stated by 16% of respondents; 25% of specialists refer to the use of biomarkers of AKI as a criterium for discontinuing the RRT. Femoral vena and right jugular vena were the most frequently used location for RRT temporary catheter placement, 54.6% of respondents declared using ultrasound guidance for catheter placement.

CONCLUSIONS

The majority of burn specialists use specific consensus classifications to detect acute kidney injury. Continuous renal replacement therapy appeared to be the most preferred option, while the expertise to deliver a particular modality and resources availability play a significant role in modality selection. The use of ultrasound and specific biomarkers for AKI evaluation is infrequent in routine clinical practice.

Comparison of hemodynamic instability among continuous, intermittent and hybrid renal replacement therapy in acute kidney injury: A systematic review of randomized clinical trials

PURPOSE

To compare hemodynamic instability during continuous, intermittent and hybrid renal replacement therapy (RRT) in critically ill patients, and its association with renal recovery and mortality.

MATERIALS AND METHODS

The search was conducted in accordance with the PRISMA guidelines which was registered at the PROSPERO Database (CRD42018086504). Randomized clinical trials (RCTs) involving critically ill patients with acute kidney injury (AKI) treated with continuous, intermittent or hybrid RRT were included. The search was performed using PubMed, Embase and Cochrane databases.

RESULTS

Out of 3442 citations retrieved, 12 RCTs were included in the systematic analysis, representing 1419 patients. Most studies (n = 8) did not report differences in hemodynamic parameters across different RTT modalities. The incidence of hypotensive episodes varied from 5 to 60% among the studies. Punctual differences on heart rate and blood pressure were observed among studies. However, studies presented high heterogeneity in terms of outcome definitions and measurement, thus making the conduction of meta-analysis impossible.

CONCLUSIONS

There is very few information available regarding hemodynamic tolerance of renal replacement therapy methods. A better standardization of hemodynamic tolerance and further reports are needed before conclusions can be drawn.

Year in Review 2021: Noteworthy Literature in Cardiothoracic Critical Care

This year marked a number of milestones in critical care. As vaccines for the SARS-CoV-2 virus became widely available and were confirmed to be exceptionally effective against severe illness and hospitalization, we were then faced with new variants and the resource-intense responses necessary to combat them. Despite challenges new and old, we have persevered and continued to provide excellent care to our patients while pushing the boundaries of clinical research. This article is a collection of studies published in 2021 relevant to critical care, with a specific focus on cardiothoracic critical care. To ignore the impact of the COVID-19 pandemic would do a disservice to our colleagues, many of whom have made incredible breakthroughs in novel therapies to the coronavirus, and yet we present additional themes of delirium, acute kidney injury, lung transplant, advances in ECMO as well as biomarkers of sepsis.

Continuous renal replacement therapy versus intermittent hemodialysis as first modality for renal replacement therapy in severe acute kidney injury: a secondary analysis of AKIKI and IDEAL-ICU studies

Background

Intermittent hemodialysis (IHD) and continuous renal replacement therapy (CRRT) are the two main RRT modalities in patients with severe acute kidney injury (AKI). Meta-analyses conducted more than 10 years ago did not show survival difference between these two modalities. As the quality of RRT delivery has improved since then, we aimed to reassess whether the choice of IHD or CRRT as first modality affects survival of patients with severe AKI.

Methods

This is a secondary analysis of two multicenter randomized controlled trials (AKIKI and IDEAL-ICU) that compared an early RRT initiation strategy with a delayed one. We included patients allocated to the early strategy in order to emulate a trial where patients would have been randomized to receive either IHD or CRRT within twelve hours after the documentation of severe AKI. We determined each patient’s modality group as the first RRT modality they received. The primary outcome was 60-day overall survival. We used two propensity score methods to balance the differences in baseline characteristics between groups and the primary analysis relied on inverse probability of treatment weighting.

Results

A total of 543 patients were included. Continuous RRT was the first modality in 269 patients and IHD in 274. Patients receiving CRRT had higher cardiovascular and total-SOFA scores. Inverse probability weighting allowed to adequately balance groups on all predefined confounders. The weighted Kaplan–Meier death rate at day 60 was 54·4% in the CRRT group and 46·5% in the IHD group (weighted HR 1·26, 95% CI 1·01–1·60). In a complementary analysis of less severely ill patients (SOFA score: 3–10), receiving IHD was associated with better day 60 survival compared to CRRT (weighted HR 1.82, 95% CI 1·01–3·28; p < 0.01). We found no evidence of a survival difference between the two RRT modalities in more severe patients.

Conclusion

Compared to IHD, CRRT as first modality seemed to convey no benefit in terms of survival or of kidney recovery and might even have been associated with less favorable outcome in patients with lesser severity of disease. A prospective randomized non-inferiority trial should be implemented to solve the persistent conundrum of the optimal RRT technique.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13054-022-03955-9.

Effects of regional citrate anticoagulation on thrombin generation, fibrinolysis and platelet function in critically ill patients receiving continuous renal replacement therapy for acute kidney injury: a prospective study

BACKGROUND

Regional citrate anticoagulation (RCA) is recommended for continuous renal replacement therapy (CRRT). However, filter life varies and premature filter clotting can occur. The aims of this explorative prospective study were to investigate the effects of RCA on thrombin generation, fibrinolysis and platelet function in critically ill patients receiving CRRT, to compare clotting parameters between systemic and intra-circuit blood samples, and to screen participants for coagulation disorders. We recruited critically ill adult patients admitted to a 30-bedded Intensive care unit in a tertiary care hospital who required CRRT with RCA for acute kidney injury (AKI). Patients with pre-existing thrombotic, bleeding tendencies or a CRRT duration less than 48 h were excluded. We measured coagulation and thrombophilia parameters at baseline. Thrombin generation, D-dimer and platelet function were measured pre-CRRT and at 12, 24, 36, 48 and 72 h after commencing CRRT using blood samples taken from the arterial line and the circuit.

RESULTS

At baseline, all eleven patients (mean age 62.4 years, 82% male) had Factor VIII and von Willebrand Factor concentrations above reference range and significantly increased peak thrombin generation. During CRRT, there were no significant changes in systemic maximum peak thrombin generation, time to peak thrombin generation, fibrinogen, D-dimer and platelet function analysis. We observed no significant difference between paired samples taken from the patient's arterial line and the circuit.

CONCLUSIONS

Critically ill patients with AKI requiring CRRT are hypercoagulable. Citrate used for anticoagulation during CRRT does not affect thrombin generation, D-dimer or platelet function. Systemic clotting parameters reflect intra-circuit results.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02486614. Registered 01 July 2015-Registered after recruitment of first patient. https://clinicaltrials.gov/ct2/show/NCT02486614.

Sustained low efficiency dialysis is non-inferior to continuous renal replacement therapy in critically ill patients with acute kidney injury: A comparative meta-analysis

BACKGROUND

Critically ill adults with acute kidney injury (AKI) experience considerable morbidity and mortality. This systematic review aimed to compare the effectiveness of continuous renal replacement therapy (CCRT) versus sustained low efficiency dialysis (SLED) for individuals with AKI.

METHODS

We carried out a systematic search of existing databases according to standard methods and random effects models were used to generate the overall estimate. Heterogeneity coefficient was also calculated for each outcome measure.

RESULTS

Eleven studies having 1160 patients with AKI were included in the analyses. Meta-analysis results indicated that there was no statistically significant difference between SLED versus continuous renal replacement therapy (CRRT) in our primary outcomes, like mortality rate (rate ratio [RR] 0.67, 95% confidence interval [CI] 0.44-1.00; P = .05), renal recovery (RR 1.08, 95% CI 0.83-1.42; P = .56), and dialysis dependence (RR = 1.03, 95% CI 0.69-1.53; P = .89). Also, no statistically significant difference was observed for between SLED versus CRRT in the secondary outcomes: that is, length of intensive care unit stay (mean difference -0.16, 95% CI -0.56-0.22; P = .41) and fluid removal rate (mean difference -0.24, 95% CI -0.72-0.24; P = .32). The summary mean difference indicated that there was a significant difference in the serum phosphate clearance among patients treated with SLED and CRRT (mean difference -1.17, 95% CI -1.90 to -0.44, P = .002).

CONCLUSIONS

The analysis indicate that there was no major advantage of using continuous renal replacement compared with sustained low efficiency dialysis in hemodynamically unstable AKI patients. Both modalities are equally safe and effective in treating AKI among critically ill patients.

Mortality and associated risk factors in perioperative acute kidney injury treated with continuous renal replacement therapy

Background

Perioperative acute kidney injury (AKI) is associated with multiple postoperative complications leading to prolonged hospital stay and higher costs. AKI requiring continuous renal replacement therapy (CRRT) after surgery has an incidence of 2–6% and mortality approximates 40–60%. Previous studies examining mortality in perioperative AKI patients managed with CRRT have concentrated on cardiac surgery patients and there are very limited data on broad surgical patient populations requiring CRRT. We examined long-term mortality and factors associated with poor outcome in a broad surgical population requiring CRRT for perioperative AKI during a 10-year period.

Methods

Surgical patients admitted to the intensive care unit (ICU) of academic tertiary hospital requiring CRRT between years 2010–2019 were included. CRRT was performed using regional citrate-calcium-anticoagulation. Extracted data included patient demographics, comorbidities, and clinical parameters at ICU admission and at the initiation of CRRT. Creatinine and estimated glomerular filtration rate (eGFR) were measured at 1 year after ICU admission.

Results

A total of 157 patients were included in the study. ICU mortality was 42.7%, 90-day mortality 58.0% and 1-year mortality 62.4%. Blood lactate at ICU admission and CRRT initiation were independently associated with mortality in the multivariate models. Patients with lactate > 4 mmol/l had higher mortality than patients with normal lactate (77% vs. 21%) (p < 0.001). Creatinine (p = 0.004) and eGFR (p < 0.001) remained significantly altered at 1 year of follow-up compared to baseline.

Conclusions

Patients undergoing surgery and requiring perioperative CRRT in the ICU have a high risk of mortality. Mortality appears to be independently associated with lactate levels.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13741-021-00227-y.

Timing of renal-replacement therapy in intensive care unit-related acute kidney injury

PURPOSE OF REVIEW

The optimal timing of renal-replacement therapy (RRT) initiation for the management of acute kidney injury (AKI) in the intensive care unit (ICU) is frequently controversial. An earlier-strategy has biological rationale, even in the absence of urgent indications; however, a delayed-strategy may prevent selected patients from receiving RRT and avoid complications related to RRT.

RECENT FINDINGS

Previous studies assessing the optimal timing of RRT initiation found conflicting results, contributing to variation in clinical practice. The recent multinational trial, standard vs. accelerated initiation of renal replacement therapy in acute kidney injury (STARRT-AKI) found no survival benefit and a higher risk of RRT dependence with an accelerated compared to a standard RRT initiation strategy in critically ill patients with severe AKI. Nearly 40% of patients allocated to the standard-strategy group did not receive RRT. The Artificial Kidney Initiation in Kidney Injury-2 (AKIKI-2) trial further assessed delayed compared to more-delayed strategies for RRT initiation. The more-delayed strategy did not confer an increase in RRT-free days and was associated with a higher risk of death.

SUMMARY

Early preemptive initiation of RRT in critically ill patients with AKI does not confer clear clinical benefits. However, protracted delays in RRT initiation may be harmful.

Discharge Documentation and Follow-Up of Critically Ill Patients With Acute Kidney Injury Treated With Kidney Replacement Therapy: A Retrospective Cohort Study

Leading organisations recommend follow-up of acute kidney injury (AKI) survivors, as these patients are at risk of long-term complications and increased mortality. Information transfer between specialties and from tertiary to primary care is essential to ensure timely and appropriate follow-up. Our aim was to examine the association between completeness of discharge documentation and subsequent follow-up of AKI survivors who received kidney replacement therapy (KRT) in the Intensive Care Unit (ICU). We retrospectively analysed the data of 433 patients who had KRT for AKI during ICU admission in a tertiary care centre in the UK between June 2017 and May 2018 and identified patients who were discharged from hospital alive. Patients with pre-existing end-stage kidney disease and patients who were transferred from hospitals outside the catchment area were excluded. The primary objective was to assess the completeness of discharge documentation from critical care and hospital; secondary objectives were to determine cardiovascular medications reconciliation after AKI, and to investigate kidney care and outcomes at 1 year. The development of AKI and the need for KRT were mentioned in 85 and 82% of critical care discharge letters, respectively. Monitoring of kidney function post-discharge was recommended in 51.6% of critical care and 36.3% of hospital discharge summaries. Among 35 patients who were prescribed renin-angiotensin-aldosterone system inhibitors before hospitalisation, 15 (42.9%) were not re-started before discharge from hospital. At 3 months, creatinine and urine protein were measured in 88.2 and 11.8% of survivors, respectively. The prevalence of chronic kidney disease stage III or worse increased from 27.2% pre-hospitalisation to 54.9% at 1 year (p < 0.001). Our data demonstrate that discharge summaries of patients with AKI who received KRT lacked essential information. Furthermore, even in patients with appropriate documentation, renal follow-up was poor suggesting the need for more education and streamlined care pathways.

Acute pediatric kidney replacement therapies in Europe: demographic results from the EurAKId Registry

BACKGROUND

Acute kidney injury (AKI), particularly that requiring dialysis, is a severe complication in hospitalized children associated with high morbidity and mortality. A prospective European AKI registry (EurAKId registry, NCT02960867) was created to describe the epidemiology and outcomes of pediatric patients treated with acute dialysis.

METHODS

Children were recruited who were between 0 and 18 years of age and were treated both in and outside the Pediatric Intensive Care Unit (PICU) with peritoneal dialysis (PD), hemodialysis (HD) or continuous kidney replacement therapy (CKRT) for AKI or metabolic derangement, fluid overload (FO), sepsis, or respiratory distress. Five age groups and 12 categories of primary diseases were defined.

RESULTS

Data on 340 patients were analyzed, of whom 86% received dialysis for AKI and 14% for reasons other than AKI. Boys accounted for 60% of the patients. Illness severity was greater in children with cardiac and hematologic diseases than those with kidney diseases. Most patients received dialysis in the PICU (84%). The most frequently used dialysis modality was CKRT (64%), followed by PD (14%) and HD (14%). The overall survival rate was 65%. Survival was significantly lower in children with three comorbidities than in children with no comorbidities (41% and 83%, p < 0.001).

CONCLUSIONS

The EurAKId registry is the first prospective registry considering pediatric acute kidney replacement therapies (KRT) in both critical and non-critical care settings, focusing on the three dialysis modalities in Europe. The clinical indications for KRT have expanded; our population was characterized by critically ill patients, primarily boys, who frequently received dialysis in the PICU with CKRT.

Early versus Late Initiation of Renal Replacement Therapy: Have We Reached the Consensus? An Updated Meta-Analysis

OBJECTIVES

The objective of this study is to compare early versus late/standard initiation of renal replacement therapy (RRT) in patients with acute kidney injury (AKI).

DATA SOURCES

MEDLINE/PubMed, Embase, Google Scholar, Cochrane Central Register of Controlled Trials, and the Cochrane renal group till August 15, 2020.

STUDY SELECTION

Randomized controlled trials (RCTs) comparing early versus late initiation of RRT in patients with AKI were included. The primary outcome measures were all-cause mortality and dialysis dependence on day 90. Secondary outcome measures were length of stay, recovery of renal functions, and adverse events.

DATA EXTRACTION

Two authors independently performed study selection and data extraction using data extraction forms.

DATA SYNTHESIS

A total of 14 RCTs with 5,234 participants were included. Three trials had low risk of bias in all the domains. There was no significant difference in the overall mortality (risk ratio (RR): 0.99; 95% confidence interval (CI): 0.89, 1.10; moderate certainty of evidence), day 30 mortality (RR: 1.0; 95% CI: 0.91, 1.09; high certainty of evidence), day 90 mortality (RR: 1.00; 95% CI: 0.88, 1.13; high certainty of evidence), and ICU mortality (RR: 1.00; 95% CI: 0.90, 1.10; moderate certainty of evidence) between the early versus late RRT. Dialysis dependence on day 90 was significantly higher in the patients assigned to early RRT (RR: 1.55; 95% CI: 1.15, 2.09; moderate certainty of evidence). The treatment-emergent adverse events (hypophosphatemia and hypotension) were significantly higher in the patients assigned to early RRT.

CONCLUSION

There is no added benefit of early initiation of RRT in patient with AKI; this may lead to treatment-emergent adverse events. Delaying the initiation of RRT with close monitoring and initiating RRT for emergent indications should be the acceptable criterion in critical care nephrology. Prospero Registration: CRD42016043092.

Acute Kidney Injury Recovery Patterns in Critically Ill Patients: Results of a Retrospective Cohort Study

OBJECTIVES

Acute kidney injury, acute kidney injury severity, and acute kidney injury duration are associated with both short- and long-term outcomes. Despite recent definitions, only few studies assessed pattern of renal recovery and time-dependent competing risks are usually disregarded. Our objective was to describe pattern of acute kidney injury recovery, change of transition probability over time and their risk factors.

DESIGN

Monocenter retrospective cohort study. Acute kidney injury was defined according to Kidney Disease Improving Global Outcomes definition. Renal recovery was defined as normalization of both serum creatinine and urine output criteria. Competing risk analysis, time-inhomogeneous Markov model, and group-based trajectory modeling were performed.

SETTING

Monocenter study.

PATIENTS

Consecutive patients admitted in ICU from July 2018 to December 2018 were included.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Three-hundred fifty patients were included. Acute kidney injury occurred in 166 patients at ICU admission, including 64 patients (38.6%) classified as acute kidney disease according to Acute Disease Quality Initiative definition and 44 patients (26.5%) who could not be classified. Cumulative incidence of recovery was 25 % at day 2 (95% CI, 18-32%) and 35% at day 7 (95% CI, 28-42%). After adjustment, need for mechanical ventilation (subdistribution hazard ratio, 0.42; 95% CI, 0.23-0.74) and severity of the acute kidney injury (stage 3 vs stage 1 subdistribution hazard ratio, 0.11; 95% CI, 0.03-0.35) were associated with lack of recovery. Group-based trajectory modeling identified three clusters of temporal changes in this setting, associated with both acute kidney injury recovery and patients' outcomes.

CONCLUSIONS

In this study, we demonstrate Acute Disease Quality Initiative to allow recovery pattern classification in 75% of critically ill patients. Our study underlines the need to take into account competing risk factors when assessing recovery pattern in critically ill patients.

Prospective model for predicting renal recovery in cardiac surgery patients with acute kidney injury requiring renal replacement therapy

Aim

To develop a model for predicting renal recovery in cardiac surgery patients with acute kidney injury (AKI) requiring renal replacement therapy (RRT).

Methods

Data from a prospective randomized controlled trial, conducted in a tertiary hospital to compare the survival effect of two dosages of hemofiltration for continuous RRT in cardiac surgery patients between 20 March 2012 and 9 August 2015, were used to develop the model. The outcome was renal recovery defined as alive and dialysis‐free 90 days after RRT initiation. Multivariate logistic regression with a stepwise backward selection of variables based on Akaike Information Criterion was applied to develop the model, which was internally validated using bootstrapping. Model discrimination, calibration and clinical value were assessed using the concordance index (C‐Index), calibration plots and decision curve analysis, respectively.

Results

Totally, 211 patients with AKI requiring RRT (66.8% male) with median age of 57 years were included. The incidence of renal recovery was 33.2% (n = 70). The model included six variables: body mass index stratification, baseline estimated glomerular filtration rate, hypertension, sepsis, mean arterial pressure and mechanical ventilation. The C‐Index for this model was 0.807 (95% CI, 0.744–0.870). After correction by the bootstrap, the C‐Index was 0.780 (95% CI, 0.720–0.845). The calibration plots indicated good consistency between actual observations and model prediction of renal recovery. Decision curve analysis demonstrated the model was clinical usefulness.

Conclusion

We developed and validated a model to predict the chance of renal recovery in cardiac surgery patients with AKI requiring RRT.

This validated model based on prospective cohort data to predict the chance of renal recovery in cardiac surgery patients, especially after acute dialysis provides values to alert clinical decision and information for post AKI care.

Renal replacement therapy modality in critically ill patients with acute kidney injury - A network meta-analysis of randomized controlled trials

PURPOSE

This network meta-analysis aims to compare the efficacy and safety of various renal replacement therapy (RRT) modalities in critically ill patients with acute kidney injury (AKI).

MATERIALS AND METHODS

We searched the electronic databases for randomized controlled trials (RCTs) comparing different RRT modalities, including continuous RRT, intermittent RRT, hybrid RRT, and peritoneal dialysis (PD), in critically ill patients with AKI through July 26, 2020. The primary outcomes were renal recovery and short-term mortality. The study protocol was registered with PROSPERO (CRD42020188115).

RESULTS

Twenty-three studies were included. No difference in the renal recovery or short-term mortality was observed among the four RRT modalities (low certainty). The four RRT modalities had similar effects on the incidence of infectious complications (low certainty). PD was associated with less fluid removal volume and lower incidence of hypotension compared with the extracorporeal modalities, yet no difference in the two outcomes was identified among the extracorporeal modalities (very low to moderate certainty).

CONCLUSIONS

No superiority of one particular RRT modality over another in terms of renal recovery and short-term mortality in critically ill patients with AKI. PD exhibited worse fluid removal and better safety in the prevention of hypotension than the extracorporeal modalities.

Starting Kidney Replacement Therapy in Critically III Patients with Acute Kidney Injury

Kidney replacement therapy (KRT) is a core organ support in critical care settings. In patients suitable for escalation in support, who develop acute kidney injury (AKI) complications and urgent indications, there is consensus that KRT should be promptly initiated. In the absence of such urgent indications, the optimal timing has been less certain. Current clinical practice guidelines do not present strong recommendations for when to start KRT for patients with AKI in the absence of life-threatening and urgent indications. This article discusses how best to provide KRT to critically ill patients with severe AKI.

Early Peritoneal Dialysis Ameliorates Blast Lung Injury by Alleviating Pulmonary Edema and Inflammation

BACKGROUND

Blast lung injury is a high-energy trauma with high mortality for explosion victims. A treatment for blast lung injury is still lacking. The aim of this study was to observe the efficacy and mechanism of peritoneal dialysis combined with glucocorticoids (GC) in the treatment of blast lung injury in rats.

METHODS

Rats were randomly divided into five groups: control, sham, GC, peritoneal dialysis (dialysis for short), and dialysis + GC groups. All rats were injured by a biological shock tube-I.

RESULTS

The lung water levels in the dialysis group and dialysis + GC group were significantly lower than that in the control group at 6 and 24 h after blast injury. The oxygenation index, forced vital capacity, maximum midexpiratory flow, and functional residual capacity of rats in the dialysis and dialysis + GC groups were significantly higher than those in the control group. The serum levels of interleukin (IL)-1β, IL-6, tumor necrosis factor- α, monocyte chemoattractant protein-1, C-reactive protein, and IL-10 in the dialysis and dialysis + GC groups were significantly lower than those in the control group. Genome-wide mRNA microarray results showed that the aquaporin 1 level in the lung tissue of the dialysis group was 6.67 times higher than that in the control group.

CONCLUSION

Early peritoneal dialysis can attenuate pulmonary edema and inflammation, and protect acute lung injury after blast injury.

Comparison between regional citrate anticoagulation and heparin for intermittent hemodialysis in ICU patients: a propensity score-matched cohort study

BACKGROUND

Regional citrate anticoagulation (RCA) is the gold standard of anticoagulation for continuous renal replacement therapy but is rarely used for intermittent hemodialysis (IHD) in ICU. Few studies assessed the safety and efficacy of RCA during IHD in ICU; however, no data are available comparing RCA to heparin anticoagulation, which are commonly used for IHD. The aim of this study was to assess the efficacy and safety of RCA compared to heparin anticoagulation during IHD.

METHODS

This retrospective single-center cohort study included consecutive ICU patients treated with either heparin anticoagulation (unfractionated or low-molecular-weight heparin) or RCA for IHD from July to September in 2015 and 2017. RCA was performed with citrate infusion according to blood flow and calcium infusion by diffusive influx from dialysate. Using a propensity score analysis, as the primary endpoint we assessed whether RCA improved efficacy, quantified with Kt/V from the ionic dialysance, compared to heparin anticoagulation. The secondary endpoint was safety. Exploratory analyses were performed on the changes in efficacy and safety between the implementation period (2015) and at long term (2017).

RESULTS

In total, 208 IHD sessions were performed in 56 patients and were compared (124 RCA and 84 heparin coagulation). There was no difference in Kt/V between RCA and heparin (0.95 ± 0.38 vs. 0.89 ± 0.32; p = 0.98). A higher number of circuit clotting (12.9% vs. 2.4%; p = 0.02) and premature interruption resulting from acute high transmembrane pressure (21% vs. 7%; p = 0.02) occurred in the RCA sessions compared to the heparin sessions. In the propensity score-matching analysis, RCA was associated with an increased risk of circuit clotting (absolute differences = 0.10, 95% CI [0.03-0.18]; p = 0.008). There was no difference in efficacy and safety between the two time periods (2015 and 2017).

CONCLUSION

RCA with calcium infusion by diffusive influx from dialysate for IHD was easy to implement with stable long-term efficacy and safety but did not improve efficacy and could be associated with an increased risk of circuit clotting compared to heparin anticoagulation in non-selected ICU patients. Randomized trials to determine the best anticoagulation for IHD in ICU patients should be conducted in a variety of settings.

How To Prescribe And Troubleshoot Continuous Renal Replacement Therapy: A Case-Based Review

Continuous RRT (CRRT) is the preferred dialysis modality for solute management, acid-base stability, and volume control in patients who are critically ill with AKI in the intensive care unit (ICU). CRRT offers multiple advantages over conventional hemodialysis in the critically ill population, such as greater hemodynamic stability, better fluid management, greater solute control, lower bleeding risk, and a more continuous (physiologic) approach of kidney support. Despite its frequent use, several aspects of CRRT delivery are still not fully standardized, or do not have solid evidence-based foundations. In this study, we provide a case-based review and recommendations of common scenarios and interventions encountered during the provision of CRRT to patients who are critically ill. Specific focus is on initial prescription, CRRT dosing, and adjustments related to severe hyponatremia management, concomitant extracorporeal membrane oxygenation support, dialysis catheter placement, use of regional citrate anticoagulation, and antibiotic dosing. This case-driven simulation is made as the clinical status of the patient evolves, and is on the basis of step-wise decisions made during the care of this patient, according to the specific patient's needs and the logistics available at the corresponding institution.

Development, implementation and outcomes of a quality assurance system for the provision of continuous renal replacement therapy in the intensive care unit

Critically ill patients with requirement of continuous renal replacement therapy (CRRT) represent a growing intensive care unit (ICU) population. Optimal CRRT delivery demands continuous communication between stakeholders, iterative adjustment of therapy, and quality assurance systems. This Quality Improvement (QI) study reports the development, implementation and outcomes of a quality assurance system to support the provision of CRRT in the ICU. This study was carried out at the University of Kentucky Medical Center between September 2016 and June 2019. We implemented a quality assurance system using a step-wise approach based on the (a) assembly of a multidisciplinary team, (b) standardization of the CRRT protocol, (c) creation of electronic CRRT flowsheets, (d) selection, monitoring and reporting of quality metrics of CRRT deliverables, and (e) enhancement of education. We examined 34-month data comprising 1185 adult patients on CRRT (~ 7420 patient-days of CRRT) and tracked selected QI outcomes/metrics of CRRT delivery. As a result of the QI interventions, we increased the number of multidisciplinary experts in the CRRT team and ensured a continuum of education to health care professionals. We maximized to 100% the use of continuous veno-venous hemodiafiltration and doubled the percentage of patients using regional citrate anticoagulation. The delivered CRRT effluent dose (~ 30 ml/kg/h) and the delivered/prescribed effluent dose ratio (~ 0.89) remained stable within the study period. The average filter life increased from 26 to 31 h (p = 0.020), reducing the mean utilization of filters per patient from 3.56 to 2.67 (p = 0.054) despite similar CRRT duration and mortality rates. The number of CRRT access alarms per treatment day was reduced by 43%. The improvement in filter utilization translated into ~ 20,000 USD gross savings in filter cost per 100-patient receiving CRRT. We satisfactorily developed and implemented a quality assurance system for the provision of CRRT in the ICU that enabled sustainable tracking of CRRT deliverables and reduced filter resource utilization at our institution.

RRT Selection for AKI Patients With Critical Illness

Acute kidney injury (AKI) is a critical burden on intensive care units in Asia. Renal replacement therapy (RRT) acts as strong supportive care for severe AKI. However, various RRT modalities are used in Asia because of the diversity in ethics, climate, geographic features, and socioeconomic status. Extracorporeal blood purification is used commonly in Asian intensive care units; however, intermittent RRT is preferred in developing countries because of cost and infrastructure issues. Conversely, continuous RRT is preferred in developed countries, indicating the predominance of hospital-acquired AKI patients with complications of hemodynamic instability. Peritoneal dialysis is delivered less frequently, although several studies have suggested promising results for peritoneal dialysis in AKI treatment. Of note, not all RRT modalities are available as a standard procedure in some Asian regions, and it is absolutely necessary to develop a sustainable infrastructure that can deliver optimal care for all AKI patients.

Management of Acute Kidney Injury Following Major Abdominal Surgery: A Contemporary Review

Acute kidney injury (AKI) is a frequent occurrence following major abdominal surgery and is independently associated with both in-hospital and long-term mortality, as well as with a higher risk of progressing to chronic kidney disease (CKD) and cardiovascular events. Postoperative AKI can account for up to 40% of in-hospital AKI cases. Given the differences in patient characteristics and the pathophysiology of postoperative AKI, it is inappropriate to assume that the management after noncardiac and nonvascular surgery are the same as those after cardiac and vascular surgery. This article provides a comprehensive review on the available evidence on the management of postoperative AKI in the setting of major abdominal surgery.

Timing of Initiation of Renal-Replacement Therapy in Acute Kidney Injury

BACKGROUND

Acute kidney injury is common in critically ill patients, many of whom receive renal-replacement therapy. However, the most effective timing for the initiation of such therapy remains uncertain.

METHODS

We conducted a multinational, randomized, controlled trial involving critically ill patients with severe acute kidney injury. Patients were randomly assigned to receive an accelerated strategy of renal-replacement therapy (in which therapy was initiated within 12 hours after the patient had met eligibility criteria) or a standard strategy (in which renal-replacement therapy was discouraged unless conventional indications developed or acute kidney injury persisted for >72 hours). The primary outcome was death from any cause at 90 days.

RESULTS

Of the 3019 patients who had undergone randomization, 2927 (97.0%) were included in the modified intention-to-treat analysis (1465 in the accelerated-strategy group and 1462 in the standard-strategy group). Of these patients, renal-replacement therapy was performed in 1418 (96.8%) in the accelerated-strategy group and in 903 (61.8%) in the standard-strategy group. At 90 days, death had occurred in 643 patients (43.9%) in the accelerated-strategy group and in 639 (43.7%) in the standard-strategy group (relative risk, 1.00; 95% confidence interval [CI], 0.93 to 1.09; P = 0.92). Among survivors at 90 days, continued dependence on renal-replacement therapy was confirmed in 85 of 814 patients (10.4%) in the accelerated-strategy group and in 49 of 815 patients (6.0%) in the standard-strategy group (relative risk, 1.74; 95% CI, 1.24 to 2.43). Adverse events occurred in 346 of 1503 patients (23.0%) in the accelerated-strategy group and in 245 of 1489 patients (16.5%) in the standard-strategy group (P<0.001).

CONCLUSIONS

Among critically ill patients with acute kidney injury, an accelerated renal-replacement strategy was not associated with a lower risk of death at 90 days than a standard strategy. (Funded by the Canadian Institutes of Health Research and others; STARRT-AKI ClinicalTrials.gov number, NCT02568722.).

Acute cardiorenal syndrome in acute heart failure: focus on renal replacement therapy

Almost half of hospitalised patients with acute heart failure develop acute cardiorenal syndrome. Treatment consists of optimisation of fluid status and haemodynamics, targeted therapy for the underlying cardiac disease, optimisation of heart failure treatment and preventive measures such as avoidance of nephrotoxic agents. Renal replacement therapy may be temporarily needed to support kidney function, mostly in case of diuretic resistant fluid overload or severe metabolic derangement. The best timing to initiate renal replacement therapy and the best modality in acute heart failure are still under debate. Several modalities are available such as intermittent and continuous renal replacement therapy as well as hybrid techniques, based on two main principles: haemofiltration and haemodialysis. Although continuous techniques have been associated with less haemodynamic instability and a greater chance of renal recovery, cohort data are conflicting and randomised controlled trials have not shown a difference in recovery or mortality. In the presence of diuretic resistance, isolated ultrafiltration with individualisation of ultrafiltration rates is a valid option for decongestion in acute heart failure patients. Practical tools to optimise the use of renal replacement therapy in acute heart failure-related acute cardiorenal syndrome were discussed.