Early High-Volume Hemofiltration versus Standard Care for Post-Cardiac Surgery Shock. The HEROICS Study

Selection of timing of continuous renal replacement therapy in patients with acute kidney injury: A meta-analysis of randomized controlled trials

Acute kidney injury (AKI) is associated with high death rates and unfavorable outcomes. Previous studies evaluating the effect of the timing of CRRT therapy on the prognosis of patients with AKI have shown inconsistent results. Consequently, we aimed to assess the impact of continuous renal replacement therapy (CRRT) initiation on the outcomes of patients with AKI. This meta-analysis identified eligible randomized controlled trials (RCTs) via comprehensive searches of PubMed, Embase, and the Cochrane databases from their creation until June 1, 2024. Outcomes, including 28-, 60-, and 90-day mortality and adverse event incidence, were compared between the early and delayed CRRT groups post-randomization. Twelve RCTs (n = 1,244) were included. Meta-analysis indicated that early initiation of CRRT did not significantly affect 28-day mortality (RR 0.91 [0.79, 1.06]; p =  0.23; I2 =  0). Early CRRT initiation correlated with a shorter length of ICU stay [MD -3.24 (-5.14, -1.35); p = 0.0008; I2 = 36%] but did not significantly affect hospital stay duration [MD -7.00 (-14.60, 0.60); p = 0.07; I2 = 38%]. The early initiation of CRRT was associated with a significant reduction in RRT dependency at discharge [RR 0.57 (0.32, 0.99); P = 0.05; I2 = 0%; P = 0.47]. Compared to delayed CRRT, early CRRT was associated with higher incidence rates of hypotension [RR 1.26 (1.06, 1.50); p = 0.008; I2 = 0%], thrombocytopenia [RR 1.53 (1.11, 2.10); p = 0.009; I2 = 0%], and hypophosphatemia [RR 3.35 (2.18, 5.15); p < 0.00001; I2 = 11%]. Our findings suggest that although early CRRT initiation is associated with short intensive care unit stays and reduced RRT dependence, it has no significant effect on mortality and is in fact associated with higher incidence rates of hypotension, thrombocytopenia, and hypophosphatemia. Therefore, early CRRT should be used clinically with caution and consideration of potential adverse effects.

Extracorporeal Blood Purification and Acute Kidney Injury in Cardiac Surgery: The SIRAKI02 Randomized Clinical Trial

Importance

Cardiac surgery-associated acute kidney injury (CSA-AKI) remains a significant problem following cardiopulmonary bypass (CPB). Various strategies are proposed to attenuate CSA-AKI, including extracorporeal blood purification (EBP), but little is known about the effect of EBP through an acrylonitrile-sodium methallylsulfonate/polyethyleneimine membrane during CPB.

Objective

To determine whether the use of an EBP device in a nonemergent cardiac surgery population reduces CSA-AKI after CPB.

Design, Setting, and Participants

This double-blind, randomized clinical trial was conducted in 2 tertiary hospitals in Spain. Patients 18 years or older undergoing nonemergent cardiac surgery who were at high risk for CSA-AKI were enrolled from June 15, 2016, through November 5, 2021, with follow-up data through February 5, 2022. Of 1156 patients assessed, 343 patients were randomized (1:1) to either receive EBP or standard care.

Intervention

Nonselective EBP device connected to the CPB circuit.

Main Outcomes and Measures

The primary outcome was the rate of CSA-AKI in the 7 days after randomization.

Results

Among 343 patients randomized (169 to receive EBP and 174 to receive usual care), the mean (SD) age was 69 (9) years and 119 were females. The rate of CSA-AKI was 28.4% (95% CI, 21.7%-35.8%) in the EBP group vs 39.7% (95% CI, 32.3%-47.3%) in the standard care group (P = .03), with an adjusted difference of 10.4% (95% CI, 2.3%-18.5%) using a log-binomial model (P = .01). No significant differences (P > .05) were observed in most of the predefined clinical secondary end points or post hoc exploratory end points. In a sensitivity analysis, EBP was found to be more effective in terms of CSA-AKI reduction in patients with chronic kidney disease, diabetes, hypertension, low left ventricular ejection fraction (<40%), and lower body mass index (<30). No differences were observed between the groups in adverse events tracking.

Conclusions and Relevance

The use of a nonselective EBP device connected to the CPB circuit in a nonemergent population of patients undergoing cardiac surgery was associated with a significant reduction of CSA-AKI in the first 7 days after surgery.

Trial Registration

ClinicalTrials.gov Identifier: NCT02518087.

Programs and processes for advancing pediatric acute kidney support therapy in hospitalized and critically ill children: a report from the 26th Acute Disease Quality Initiative (ADQI) consensus conference

Pediatric acute kidney support therapy (paKST) programs aim to reliably provide safe, effective, and timely extracorporeal supportive care for acutely and critically ill pediatric patients with acute kidney injury (AKI), fluid and electrolyte derangements, and/or toxin accumulation with a goal of improving both hospital-based and lifelong outcomes. Little is known about optimal ways to configure paKST teams and programs, pediatric-specific aspects of delivering high-quality paKST, strategies for transitioning from acute continuous modes of paKST to facilitate rehabilitation, or providing effective short- and long-term follow-up. As part of the 26th Acute Disease Quality Initiative Conference, the first to focus on a pediatric population, we summarize here the current state of knowledge in paKST programs and technology, identify key knowledge gaps in the field, and propose a framework for current best practices and future research in paKST.

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.

Acute Kidney Injury: Gaps and Opportunities for Knowledge and Growth

Acute kidney injury (AKI) occurs frequently in hospitalized patients, regardless of age or prior medical history. Increasing awareness of the epidemiologic problem of AKI has directly led to increased study of global recognition, diagnostic tools, both reactive and proactive management, and analysis of long-term sequelae. Many gaps remain, however, and in this article we highlight opportunities to add significantly to the increasing bodies of evidence surrounding AKI. Practical considerations related to initiation, prescription, anticoagulation, and monitoring are discussed. In addition, the importance of AKI follow-up evaluation, particularly for those surviving the receipt of renal replacement therapy, is highlighted as a push for global equity in the realm of critical care nephrology is broached. Addressing these gaps presents an opportunity to impact patient care directly and improve patient outcomes.

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.

Timing of initiation of renal replacement therapy for patients with acute kidney injury: A meta-analysis of RCTs

PURPOSE

To assess the effects of delayed versus early renal replacement therapy (RRT) initiation for patients with AKI.

METHODS

Related RCTs of RRT initiated at different times published on PubMed, Web of Science, Embase, and Cochrane Library were searched.

RESULTS

Fifteen RCTs studies with 5395 patients were included. The results showed that the 28-day mortality (RR 1.01; 95% CI 0.94 ~ 1.08; p = 0.80), 60-day mortality (RR 1.00; 95% CI 0.91 ~ 1.11; p = 0.93), 90-day mortality (RR 1.01; 95% CI 0.94 ~ 1.08; p = 0.80), dialysis dependence among survivors (RR 0.67; 95% CI 0.40 ~ 1.13; p = 0.13), length of ICU stay (RR -1.32; 95% CI -3.26 ~ 0.62; p = 0.18) and length of hospital stay among survivors(RR -0.98; 95% CI -2.89 ~ 0.92; p = 0.31) were not significantly different between the two groups. In addition, early initiation of RRT increases the incidence of hypotension (RR 1.42, 95% CI 1.23 ~ 1.63; p < 0.00001) and infectious (RR 1.36; 95% CI 1.03 ~ 1.80; p = 0.03) events.

CONCLUSION

Early initiation of RRT cannot improve the prognosis and benefit patients.

Continuous KRT: A Contemporary Review

AKI is a common complication of critical illness and is associated with substantial morbidity and risk of death. Continuous KRT comprises a spectrum of dialysis modalities preferably used to provide kidney support to patients with AKI who are hemodynamically unstable and critically ill. The various continuous KRT modalities are distinguished by different mechanisms of solute transport and use of dialysate and/or replacement solutions. Considerable variation exists in the application of continuous KRT due to a lack of standardization in how the treatments are prescribed, delivered, and optimized to improve patient outcomes. In this manuscript, we present an overview of the therapy, recent clinical trials, and outcome studies. We review the indications for continuous KRT and the technical aspects of the treatment, including continuous KRT modality, vascular access, dosing of continuous KRT, anticoagulation, volume management, nutrition, and continuous KRT complications. Finally, we highlight the need for close collaboration of a multidisciplinary team and development of quality assurance programs for the provision of high-quality and effective continuous KRT.

Timing of kidney replacement therapy initiation for acute kidney injury

BACKGROUND

Acute kidney injury (AKI) is a common condition among patients in intensive care units (ICUs) and is associated with high numbers of deaths. Kidney replacement therapy (KRT) is a blood purification technique used to treat the most severe forms of AKI. The optimal time to initiate KRT so as to improve clinical outcomes remains uncertain. This is an update of a review first published in 2018. This review complements another Cochrane review by the same authors: Intensity of continuous renal replacement therapy for acute kidney injury.

OBJECTIVES

To assess the effects of different timing (early and standard) of KRT initiation on death and recovery of kidney function in critically ill patients with AKI.

SEARCH METHODS

We searched the Cochrane Kidney and Transplant's Specialised Register to 4 August 2022 through contact with the Information Specialist using search terms relevant to this review. Studies in the Register are identified through searches of CENTRAL, MEDLINE, EMBASE, conference proceedings, the International Clinical Trials Register, ClinicalTrials and LILACS to 1 August 2022.

SELECTION CRITERIA

We included all randomised controlled trials (RCTs). We included all patients with AKI in the ICU regardless of age, comparing early versus standard KRT initiation. For safety and cost outcomes, we planned to include cohort studies and non-RCTs.

DATA COLLECTION AND ANALYSIS

Data were extracted independently by two authors. The random-effects model was used, and results were reported as risk ratios(RR) for dichotomous outcomes and mean difference(MD) for continuous outcomes, with 95% confidence intervals (CI).

MAIN RESULTS

We included 12 studies enrolling 4880 participants. Overall, most domains were assessed as being at low or unclear risk of bias. Compared to standard treatment, early KRT initiation may have little to no difference on the risk of death at day 30 (12 studies, 4826 participants: RR 0.97,95% CI 0.87 to 1.09; I²= 29%; low certainty evidence), and death after 30 days (7 studies, 4534 participants: RR 0.99, 95% CI 0.92 to 1.07; I² = 6%; moderate certainty evidence). Early KRT initiation may make little or no difference to the risk of death or non-recovery of kidney function at 90 days (6 studies, 4011 participants: RR 0.91, 95% CI 0.74 to 1.11; I² = 66%; low certainty evidence); CIs included both benefits and harms. Low certainty evidence showed early KRT initiation may make little or no difference to the number of patients who were free from KRT (10 studies, 4717 participants: RR 1.07, 95% CI 0.94 to1.22; I² = 55%) and recovery of kidney function among survivors who were free from KRT after day 30 (10 studies, 2510 participants: RR 1.02, 95% CI 0.97 to 1.07; I² = 69%) compared to standard treatment. High certainty evidence showed early KRT initiation increased the risk of hypophosphataemia (1 study, 2927 participants: RR 1.80, 95% CI 1.33 to 2.44), hypotension (5 studies, 3864 participants: RR 1.54, 95% CI 1.29 to 1.85; I² = 0%), cardiac-rhythm disorder (6 studies, 4483 participants: RR 1.35, 95% CI 1.04 to 1.75; I² = 16%), and infection (5 studies, 4252 participants: RR 1.33, 95% CI 1.00 to 1.77; I² = 0%); however, it is uncertain whether early KRT initiation increases or reduces the number of patients who experienced any adverse events (5 studies, 3983 participants: RR 1.23, 95% CI 0.90 to 1.68; I² = 91%; very low certainty evidence). Moderate certainty evidence showed early KRT initiation probably reduces the number of days in hospital (7 studies, 4589 participants: MD-2.45 days, 95% CI -4.75 to -0.14; I² = 10%) and length of stay in ICU (5 studies, 4240 participants: MD -1.01 days, 95% CI -1.60 to -0.42; I² = 0%).

AUTHORS' CONCLUSIONS

Based on mainly low to moderate certainty of the evidence, early KRT has no beneficial effect on death and may increase the recovery of kidney function. Earlier KRT probably reduces the length of ICU and hospital stay but increases the risk of adverse events. Further adequate-powered RCTs using robust and validated tools that complement clinical judgement are needed to define the optimal time of KRT in critical patients with AKI in order to improve their outcomes. The surgical AKI population should be considered in future research.

Accelerated-strategy renal replacement therapy for critically ill patients: A systematic review and meta-analysis

BACKGROUND

The aim of this study was to investigate the clinical effect and safety of accelerated-strategy initiation of renal replacement therapy (RRT) in critically ill patients.

METHODS

PubMed, Embase, OVID, EBSCO, and the Cochrane Library databases were searched for relevant articles from inception to December 30, 2020. Only RCTs that compared the clinical efficacy and safety between accelerated-strategy RRT and standard-strategy RRT among critically ill adult patients with acute kidney injury (AKI) were included. The primary outcome was 28-day mortality.

RESULTS

A total of 5279 patients in 12 RCTs were included in this meta-analysis. The 28-day mortality rates of patients treated with accelerated and standard RRT were 37.3% (969/2596) and 37.9% (976/2573), respectively. No significant difference was observed between the groups (OR, 0.92; 95% CI, 0.70-1.12; I2 = 60%). The recovery rates of renal function were 54.5% and 52.5% in the accelerated- and standard-RRT groups, respectively, with no significant difference (OR, 1.03; 95% CI, 0.89-1.19; I2 = 56%). The rate of RRT dependency was similar in the accelerated- and standard-RRT strategies (6.7% vs 5.0%; OR, 1.11; 95% CI, 0.71-1.72; I2 = 20%). The accelerated-RRT group displayed higher risks of hypotension, catheter-related infection, and hypophosphatemia than the standard-RRT group (hypotension: OR, 1.26; 95% CI, 1.10-1.45; I2 = 36%; catheter-related infection: OR, 1.90; 95% CI, 1.17-3.09; I2 = 0%; hypophosphatemia: OR, 2.11; 95% CI, 1.43-3.15; I2 = 67%).

CONCLUSIONS

Accelerated RRT does not reduce the risk of death and does not improve the recovery of kidney function among critically ill patients with AKI. In contrast, an increased risk of adverse events was observed in patients receiving accelerated RRT. However, these findings were based on low quality of evidence. Further large-scale RCTs is warranted.

The impact of early versus late initiation of renal replacement therapy in critically ill patients with acute kidney injury on mortality and clinical outcomes: a meta-analysis

Background

Renal replacement therapy (RRT) is essential in the presence of life-threatening complications associated with acute kidney injury (AKI). In the absence of urgent indications, the optimal timing for RRT initiation is still under debate. This meta-analysis aims to compare the benefits between early and late RRT initiation strategies in critically ill patients with AKI.

Methods

Studies were obtained from three databases [Medical Literature Analysis and Retrieval System Online (MEDLINE), Cochrane Central Register of Controlled Trials (CENTRAL) and Scopus], searched from inception to May 2021. The selected primary outcome was 28-day mortality. Secondary outcomes included overall mortality, recovery of renal function (RRF) and RRT-associated adverse events. A random-effects model was used for summary measures. Heterogeneity was assessed through Cochrane I² test statistics. Potential sources of heterogeneity for the primary outcome were sought using sensitivity analyses. Further subgroup analyses were conducted based on RRT modality and study population.

Results

A total of 13 randomized controlled trials including 5193 participants were analysed. No significant differences were found between early and late RRT initiation regarding 28-day mortality [risk ratio (RR) 1.00; 95% confidence interval (CI) 0.89–1.12, I² = 30%], overall mortality (RR 1.00; 95% CI 0.90–1.12, I² = 42%) and RRF (RR 1.02; 95% CI 0.92–1.13, I² = 53%). However, early RRT initiation was associated with a significantly higher incidence of hypotensive (RR 1.34; 95% CI 1.17–1.53, I² = 6%) and infectious events (RR 1.83; 95% CI 1.11–3.02, I² = 0%).

Conclusions

Early RRT initiation does not improve the 28-day and overall mortality, nor the likelihood of RRF, and increases the risk for RRT-associated adverse events, namely hypotension and infection.

Trends in Adaptive Design Methods in Dialysis Clinical Trials: A Systematic Review

Rationale & Objective

Adaptive design methods are intended to improve the efficiency of clinical trials and are relevant to evaluating interventions in dialysis populations. We sought to determine the use of adaptive designs in dialysis clinical trials and quantify trends in their use over time.

Study Design

We completed a novel full-text systematic review that used a machine learning classifier (RobotSearch) for filtering randomized controlled trials and adhered to the Preferred Reporting Items for Systematic Review and Meta-analysis (PRISMA) guidelines.

Setting & Study Populations

We searched MEDLINE (PubMed) and ClinicalTrials.gov using sensitive dialysis search terms.

Selection Criteria for Studies

We included all randomized clinical trials with patients receiving dialysis or clinical trials with dialysis as a primary or secondary outcome. There was no restriction of disease type or intervention type.

Data Extraction & Analytical Approach

We performed a detailed data extraction of trial characteristics and a completed a narrative synthesis of the data.

Results

57 studies, available as 68 articles and 7 ClinicalTrials.gov summaries, were included after full-text review (initial search, 209,033 PubMed abstracts and 6,002 ClinicalTrials.gov summaries). 31 studies were conducted in a dialysis population and 26 studies included dialysis as a primary or secondary outcome. Although the absolute number of adaptive design methods is increasing over time, the relative use of adaptive design methods in dialysis trials is decreasing over time (6.12% in 2009 to 0.43% in 2019, with a mean of 1.82%). Group sequential designs were the most common type of adaptive design method used. Adaptive design methods affected the conduct of 50.9% of trials, most commonly resulting in stopping early for futility (41.2%) and early stopping for safety (23.5%). Acute kidney injury was studied in 32 trials (56.1%), kidney failure requiring dialysis was studied in 24 trials (42.1%), and chronic kidney disease was studied in 1 trial (1.75%). 27 studies (47.4%) were supported by public funding. 44 studies (77.2%) did not report their adaptive design method in the title or abstract and would not be detected by a standard systematic review.

Limitations

We limited our search to 2 databases (PubMed and ClinicalTrials.gov) due to the scale of studies sourced (209,033 and 6,002 results, respectively).

Conclusions

Adaptive design methods are used in dialysis trials but there has been a decline in their relative use over time.

Disease Severity Determines Timing of Initiating Continuous Renal Replacement Therapies: A Systematic Review and Meta-Analysis

Background: Timing of initiating continuous renal replacement therapies (CRRTs) among the patients with acute kidney injury (AKI) in intensive care units (ICU) has been discussed over decades, but the definition of early and late CRRT initiation is still unclear. Methods: The English language randomized controlled trials (RCTs) and cohort studies were searched through MEDLINE, EMBASE, and Cochrane Library on July 19, 2019, by the two researchers independently. The study characteristics; early and late definitions; outcomes, such as all-cause, in-hospital, 28- or 30-, 60-, 90-day mortality; and renal recovery were extracted from the 18 eligible studies. Pooled relative risk ratios (RRs) and 95% CIs were estimated with the fixed effects model and random effects model as appropriate. This study is registered with PROSPERO (CRD 42020158653). Results: Eighteen studies including 3,914 patients showed benefit in earlier CRRT (n = 1,882) over later CRRT (n = 2,032) in all-cause mortality (RR 0.78, 95% CI 0.66-0.92), in-hospital mortality (RR 0.81, 95% CI 0.67-0.99), and 28- or 30-day mortality (RR 0.81, 95% CI 0.74-0.88), but in 60- and 90-day mortalities, no significant benefit was observed. The subgroup analysis showed significant benefit in the disease-severity-based subgroups on early CRRT initiation in terms of in-hospital mortality and 28- or 30-day mortality rather than the time-based subgroups. Moreover, early CRRT was found to have beneficial effects on renal recovery after CRRT (RR 1.21, 95% CI 1.01-1.45). Conclusions: Overall, compared with late CRRT, early CRRT is beneficial for short-term survival and renal recovery, especially when the timing was defined based on the disease severity. CRRT initiation on Acute Kidney Injury Network (AKIN) stage 1 or Risk, Injury, Failure, Loss of kidney function, and End-stage kidney disease (RIFLE)-Risk or less may lead to a better prognosis.

Vasopressor-Sparing Strategies in Patients with Shock: A Scoping-Review and an Evidence-Based Strategy Proposition

Despite the abundant literature on vasopressor therapy, few studies have focused on vasopressor-sparing strategies in patients with shock. We performed a scoping-review of the published studies evaluating vasopressor-sparing strategies by analyzing the results from randomized controlled trials conducted in patients with shock, with a focus on vasopressor doses and/or duration reduction. We analyzed 143 studies, mainly performed in septic shock. Our analysis demonstrated that several pharmacological and non-pharmacological strategies are associated with a decrease in the duration of vasopressor therapy. These strategies are as follows: implementing a weaning strategy, vasopressin use, systemic glucocorticoid administration, beta-blockers, and normothermia. On the contrary, early goal directed therapies, including fluid therapy, oral vasopressors, vitamin C, and renal replacement therapy, are not associated with an increase in vasopressor-free days. Based on these results, we proposed an evidence-based vasopressor management strategy.

Optimising the timing of renal replacement therapy in acute kidney injury

The optimal timing of renal replacement therapy (RRT) in critically ill patients with acute kidney injury (AKI) has been much debated. Over the past five years several studies have provided new guidance for evidence-based decision-making. High-quality evidence now supports an approach of expectant management in critically ill patients with AKI, where RRT may be deferred up to 72 h unless a life-threatening indication develops. Nevertheless, physicians’ judgment still plays a central role in identifying appropriate patients for expectant management.

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.

CRRT prescription and delivery of dose

Continuous renal replacement therapy (CRRT) is the preferred modality of extracorporeal renal support for critically ill patients with acute kidney injury (AKI). The dose of CRRT is reported as effluent flow in ml/kg body weight per hour (ml/kg/h). Solid evidence supports that the delivered CRRT effluent dose for critically ill patients with AKI should be 20-25 ml/kg/h on average. To account for treatment interruptions and the natural decline in filter efficiency over time, it is recommended to prescribe 25-30 ml/kg/h of effluent dose. However, transient higher doses of CRRT in specific clinical scenarios may be needed to accommodate specific solute control needs of a particular patient at a given time. Consequently, there should be consideration of the potential adverse consequences of non-selective clearance such as undesired antimicrobials and nutrients removal. In this manuscript, we provide a summary of evidence related to CRRT dose, practical aspects for its calculation at the time of prescribing CRRT, and considerations for addressing the expected gap between prescribed and delivered CRRT dose. We also provide a framework for monitoring and implementation of CRRT dose as a quality indicator of CRRT delivery.

Time to Initiation of Renal Replacement Therapy Among Critically Ill Patients With Acute Kidney Injury: A Current Systematic Review and Meta-Analysis

OBJECTIVES

The optimal time to initiate renal replacement therapy in critically ill patients with acute kidney injury is controversial. We investigated the effect of such earlier versus later initiation of renal replacement therapy on the primary outcome of 28-day mortality and other patient-centered secondary outcomes.

DESIGN

We searched MEDLINE (via PubMed), EMBASE, and Cochrane databases to July 17, 2020, and included randomized controlled trials comparing earlier versus later renal replacement therapy.

SETTING

Multiple centers involved in eight trials.

PATIENTS

Total of 4,588 trial participants.

INTERVENTION

Two independents investigators screened and extracted data using a predefined form. We selected randomized controlled trials in critically ill adult patients with acute kidney injury and compared of earlier versus later initiation of renal replacement therapy regardless of modality.

MEASUREMENTS AND MAIN RESULTS

Overall, 28-day mortality was similar between earlier and later renal replacement therapy initiation (38.43% vs 38.06%, respectively; risk ratio, 1.01; [95% CI, 0.94-1.09]; I2 = 0%). Earlier renal replacement therapy, however, shortened hospital length of stay (mean difference, -2.14 d; [95% CI, -4.13 to -0.14]) and ICU length of stay (mean difference, -1.18 d; [95% CI, -1.95 to -0.42]). In contrast, later renal replacement therapy decreased the use of renal replacement therapy (relative risk, 0.69; [95% CI, 0.58-0.82]) and lowered the risk of catheter-related blood stream infection (risk ratio, 0.50, [95% CI, 0.29-0.86). Among survivors, renal replacement therapy dependence at day 28 was similar between earlier and later renal replacement therapy initiation (risk ratio, 0.98; [95% CI, 0.66-1.40]).

CONCLUSIONS

Earlier or later initiation of renal replacement therapy did not affect mortality. However, earlier renal replacement therapy was associated with significantly shorter ICU and hospital length of stay, whereas later renal replacement therapy was associated with decreased use of renal replacement therapy and decreased risk of catheter-related blood stream infection. These findings can be used to guide the management of critically ill patients with acute kidney injury.

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.

Dose of Continuous Renal Replacement Therapy in Critically Ill Patients: A Bona Fide Quality Indicator

Acute kidney injury (AKI) is common in critically ill patients, and renal replacement therapy (RRT) constitutes an important aspect of acute management during critical illness. Continuous RRT (CRRT) is frequently utilized in intensive care unit settings, particularly in patients with severe AKI, fluid overload, and hemodynamic instability. The main goal of CRRT is to timely optimize solute control, acid-base, and volume status. Total effluent dose of CRRT is a deliverable that depends on multiple factors and therefore should be systematically monitored (prescribed vs. delivered) and iteratively adjusted in a sustainable mode. In this manuscript, we review current evidence of CRRT dosing and provide recommendations for its implementation as a quality indicator of CRRT delivery.

Timing of renal replacement therapy initiation for acute kidney injury in critically ill patients: a systematic review of randomized clinical trials with meta-analysis and trial sequential analysis

Background

Acute kidney injury (AKI) is a common serious complication in critically ill patients. AKI occurs in up to 50% patients in intensive care unit (ICU), with poor clinical prognosis. Renal replacement therapy (RRT) has been widely used in critically ill patients with AKI. However, in patients without urgent indications such as acute pulmonary edema, severe acidosis, and severe hyperkalemia, the optimal timing of RRT initiation is still under debate. We conducted this systematic review of randomized clinical trials (RCTs) with meta-analysis and trial sequential analysis (TSA) to compare the effects of early RRT initiation versus delayed RRT initiation.

Methods

We searched databases (PubMed, EMBASE and Cochrane Library) from inception through to July 20, 2020, to identify eligible RCTs. The primary outcome was 28-day mortality. Two authors extracted the data independently. When the I² values < 25%, we used fixed-effect mode. Otherwise, the random effects model was used as appropriate. TSA was performed to control the risk of random errors and assess whether the results in our meta-analysis were conclusive.

Results

Eleven studies involving 5086 patients were identified. Two studies included patients with sepsis, one study included patients with shock after cardiac surgery, and eight others included mixed populations. The criteria for the initiation of RRT, the definition of AKI, and RRT modalities existed great variations among the studies. The median time of RRT initiation across studies ranged from 2 to 7.6 h in the early RRT group and 21 to 57 h in the delayed RRT group. The pooled results showed that early initiation of RRT could not decrease 28-day all-cause mortality compared with delayed RRT (RR 1.01; 95% CI 0.94–1.09; P = 0.77; I² = 0%). TSA result showed that the required information size was 2949. The cumulative Z curve crossed the futility boundary and reached the required information size. In addition, early initiation of RRT could lead to unnecessary RRT exposure in some patients and was associated with a higher incidence of hypotension (RR 1.42; 95% CI 1.23–1.63; P < 0.00001; I² = 8%) and RRT-associated infection events (RR 1.34; 95% CI 1.01–1.78; P = 0.04; I² = 0%).

Conclusions

This meta-analysis suggested that early initiation of RRT was not associated with survival benefit in critically ill patients with AKI. In addition, early initiation of RRT could lead to unnecessary RRT exposure in some patients, resulting in a waste of health resources and a higher incidence of RRT-associated adverse events. Maybe, only critically ill patients with a clear and hard indication, such as severe acidosis, pulmonary edema, and hyperkalemia, could benefit from early initiation of RRT.

Continuous ultrafiltration during extracorporeal circulation and its effect on lactatemia: A randomized controlled trial

Introduction

Hyperlactatemia occurs during or after extracorporeal circulation in the form of lactic acidosis, increasing the risk of postoperative complications and the mortality rate. The aim of this study was to evaluate whether continuous high-volume hemofiltration with volume replacement through a polyethersulfone filter during the extracorporeal circulation procedure decreases postoperative lactatemia and its consequences.

Materials and methods

This was a randomized controlled trial. Patients were randomly divided into two groups of 32: with or without continuous high-volume hemofiltration through a polyethersulfone membrane. Five patients were excluded from each group during the study period. The sociodemographic characteristics, filter effects, and blood lactate levels at different times during the procedure were evaluated. Secondary endpoints were studied, such as the reduction in the intubation time and time spent in ICU.

Results

Lactatemia measurements performed during the preoperative and intraoperative phases were not significantly different between the two groups. However, the blood lactate levels in the postoperative period and at 24 hours in the intensive care unit showed a significant reduction and a possible clinical benefit in the hemofiltered group. Following extracorporeal circulation, the mean lactate level was higher (difference: 0.77 mmol/L; CI 0.95: 0.01–1.53) in the nonhemofiltered group than in the hemofiltered group (p<0.05). This effect was greater at 24 hours (p = 0.019) in the nonhemofiltered group (difference: 1.06 mmol/L; CI 0.95: 0.18–1.93) than in the hemofiltered group. The reduction of lactatemia is associated with a reduction of inflammatory mediators and intubation time, with an improvement in liver function.

Conclusions

The use and control of continuous high-volume hemofiltration through a polyethersulfone membrane during heart-lung surgery could potencially prevent postoperative complications. The reduction of lactatemia implied a reduction in intubation time, a decrease in morbidity and mortality in the intensive care unit and a shorter hospital stay.

Perioperative care in cardiac surgery

As mortality is now low for many cardiac surgical procedures, there has been an increasing focus on patient centered outcomes such as recovery and quality of life. The Enhanced Recovery After Surgery (ERAS) cardiac society recently published the first set of guidelines for cardiac surgery which will be useful as a starting point to help translate this philosophy for the benefit of those undergoing cardiac surgery. At the same time there are many advances in other areas such as mechanical circulation, diagnostics and quality metrics. We intend here to present a balanced and evidenced based review of selected aspects of current practice, encompassing both UK and international perioperative care with a focus on recent advances. For the convenience of the reader we will adopt the conventional perioperative preoperative, intraoperative and postoperative phases of care. The focus of cardiac surgical practice needs to evolve from mortality to recovery. Those specialists who work in cardiac anaesthesia and critical care are well placed to contribute to these changes. Accompanying this work is the development of technologies to improve recognition of and intervention to prevent early organ dysfunction. Measuring, benchmarking and publishing quality outcomes from cardiac surgical centres is likely to improve services and benefit our patients.

Hypophosphatemia in critically ill adults and children - A systematic review

BACKGROUND & AIMS

Phosphate is the main intracellular anion essential for numerous biological processes. Symptoms of hypophosphatemia are non-specific, yet potentially life-threatening. This systematic review process was initiated to gain a global insight into hypophosphatemia, associated morbidity and treatments.

METHODS

A systematic review was conducted (PROSPERO CRD42020163191). Nine clinically relevant questions were generated, seven for adult and two for pediatric critically ill patients, and prevalence of hypophosphatemia was assessed in both groups. We identified trials through systematic searches of Medline, EMBASE, Scopus, Cochrane Central Register of Controlled Trials, CINAHL, and Web of Science. Quality assessment was performed using the Cochrane risk of bias tool for randomized controlled trials and the Newcastle-Ottawa Scale for observational studies.

RESULTS

For all research questions, we identified 2727 titles in total, assessed 399 full texts, and retained 82 full texts for evidence synthesis, with 20 of them identified for several research questions. Only 3 randomized controlled trials were identified with two of them published only in abstract form, as well as 28 prospective and 31 retrospective studies, and 20 case reports. Relevant risk of bias regarding selection and comparability was identified for most of the studies. No meta-analysis could be performed. The prevalence of hypophosphatemia varied substantially in critically ill adults and children, but no study assessed consecutive admissions to intensive care. In both critically ill adults and children, several studies report that hypophosphatemia is associated with worse outcome (prolonged length of stay and the need for respiratory support, and higher mortality). However, there was insufficient evidence regarding the optimal threshold upon which hypophosphatemia becomes critical and requires treatment. We found no studies regarding the optimal frequency of phosphate measurements, and regarding the time window to correct hypophosphatemia. In adults, nutrient restriction on top of phosphate repletion in patients with refeeding syndrome may improve survival, although evidence is weak.

CONCLUSIONS

Evidence on the definition, outcome and treatment of clinically relevant hypophosphatemia in critically ill adults and children is scarce and does not allow answering clinically relevant questions. High quality clinical research is crucial for the development of respective guidelines.

Post-operative renal failure management in mechanical circulatory support patients

Acute kidney injury (AKI) occurs commonly in patients requiring mechanical circulatory support (MCS) after cardiothoracic surgery. The prognostic implications of AKI in this patient group relate closely to the pathophysiology and risk factors associated with the underlying disease; pre-operative, intra-operative, and post-operative variables; hemodynamic factors; and type of support device used. General approaches to AKI management, including prevention strategies, medical management, and hemodynamic support, are also applicable in patients requiring MCS. Approaches to renal replacement therapy vary depend on patient factors, device-specific factors, and local preferences and experience. In this invited narrative review, we discuss the pathophysiology, risk factors, and prognostic implications of AKI in post-operative adult patients following institution of MCS. Management strategies for AKI are presented with a focus on those supported with either extracorporeal membrane oxygenation or a ventricular assist device.

Timing of initiation of renal replacement therapy in acute kidney injury: an updated meta-analysis of randomized controlled trials

Purpose

The results from randomized controlled trials (RCTs) concerning the timing of initiation of renal replacement therapy (RRT) for patients with acute kidney injury (AKI) are still inconsistent.

Materials and methods

We searched for RCTs, as well as relevant references, focusing on the timing of RRT for AKI patients in the Medline, Embase, Cochrane Library, Google Scholar and Chinese databases from their inception to December 2018.

Results

We included 18 RCTs from 1997 to 2018 involving 2856 patients. Pooled analyses of all RCTs showed no significant difference in mortality between early initiation and delayed initiation of RRT (RR 0.98, 95% CI: 0.89 to 1.08, p = .7) (I² = 2%), and similar results were found in critically ill and community-acquired AKI patients, as well as in a subgroup of patients with sepsis and in cardiac surgery recipients. There was also no difference in the incidence of dialysis independence (RR 0.75, 95% CI: 0.47 to 1.2, p = .2) (I² = 0). However, an early RRT strategy was associated with a significantly higher incidence of the need for RRT for AKI patients (RR 1.24, 95% CI: 1.13 to 1.36, p < .01) (I² = 34%).

Conclusions

As no life-threatening complications occurred, there was no evidence to show any benefit of an early RRT strategy for critically ill or community-acquired AKI patients; in contrast, a delayed strategy might avert the need for RRT.

Acute Kidney Injury: From Diagnosis to Prevention and Treatment Strategies

Acute kidney injury (AKI) is characterized by an acute decrease in renal function that can be multifactorial in its origin and is associated with complex pathophysiological mechanisms. In the short term, AKI is associated with an increased length of hospital stay, health care costs, and in-hospital mortality, and its impact extends into the long term, with AKI being associated with increased risks of cardiovascular events, progression to chronic kidney disease (CKD), and long-term mortality. Given the impact of the prognosis of AKI, it is important to recognize at-risk patients and improve preventive, diagnostic, and therapy strategies. The authors provide a comprehensive review on available diagnostic, preventive, and treatment strategies for AKI.

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

Sepsis-associated acute kidney injury (SA-AKI) is a major issue in medical, surgical and intensive care settings and is an independent risk factor for increased mortality, as well as hospital length of stay and cost. SA-AKI encompasses a proper pathophysiology where renal and systemic inflammation play an essential role, surpassing the classic concept of acute tubular necrosis. No specific treatment has been defined yet, and renal replacement therapy (RRT) remains the cornerstone supportive therapy for the most severe cases. The timing to start RRT, however, remains controversial, with early and late strategies providing conflicting results. This article provides a comprehensive review on the available evidence on the timing to start RRT in patients with SA-AKI.

Delayed versus early initiation of renal replacement therapy for severe acute kidney injury: a systematic review and individual patient data meta-analysis of randomised clinical trials

BACKGROUND

The timing of renal replacement therapy (RRT) for severe acute kidney injury is highly debated when no life-threatening complications are present. We assessed whether a strategy of delayed versus early RRT initiation affects 28-day survival in critically ill adults with severe acute kidney injury.

METHODS

In this systematic review and individual patient data meta-analysis, we searched MEDLINE (via PubMed), Embase, and the Cochrane Central Register of Controlled Trials for randomised trials published from April 1, 2008, to Dec 20, 2019, that compared delayed and early RRT initiation strategies in patients with severe acute kidney injury. Trials were eligible for inclusion if they included critically ill patients aged 18 years or older with acute kidney injury (defined as a Kidney Disease: Improving Global Outcomes [KDIGO] acute kidney injury stage 2 or 3, or, where KDIGO was unavailable, a renal Sequential Organ Failure Assessment score of 3 or higher). We contacted the principal investigator of each eligible trial to request individual patient data. From the included trials, any patients without acute kidney injury or who were not randomly allocated were not included in the individual patient data meta-analysis. The primary outcome was all-cause mortality at day 28 after randomisation. This study is registered with PROSPERO (CRD42019125025).

FINDINGS

Among the 1031 studies identified, one study that met the eligibility criteria was excluded because the recruitment period was not recent enough, and ten (including 2143 patients) were included in the analysis. Individual patient data were available for nine studies (2083 patients), from which 1879 patients had severe acute kidney injury and were randomly allocated: 946 (50%) to the delayed RRT group and 933 (50%) to the early RRT group. 390 (42%) of 929 patients allocated to the delayed RRT group and who had available data did not receive RRT. The proportion of patients who died by day 28 did not significantly differ between the delayed RRT group (366 [44%] of 837) and the early RRT group (355 [43%] of 827; risk ratio 1·01 [95% CI 0·91 to 1·13], p=0·80), corresponding to an overall risk difference of 0·01 (95% CI -0·04 to 0·06). There was no heterogeneity across studies (I²=0%; τ²=0), and most studies had a low risk of bias.

INTERPRETATION

The timing of RRT initiation does not affect survival in critically ill patients with severe acute kidney injury in the absence of urgent indications for RRT. Delaying RRT initiation, with close patient monitoring, might lead to a reduced use of RRT, thereby saving health resources.

FUNDING

None.

Diagnostics, Risk Factors, Treatment and Outcomes of Acute Kidney Injury in a New Paradigm

Acute kidney injury (AKI) is a common clinical condition among patients admitted in the hospitals. The condition is associated with both increased short-term and long-term mortality. With the development of a standardized definition for AKI and the acknowledgment of the impact of AKI on patient outcomes, there has been increased recognition of AKI. Two advances from past decades, the usage of computer decision support and the discovery of AKI biomarkers, have the ability to advance the diagnostic method to and further management of AKI. The increasingly widespread use of electronic health records across hospitals has substantially increased the amount of data available to investigators and has shown promise in advancing AKI research. In addition, progress in the finding and validation of different forms of biomarkers of AKI within diversified clinical environments and has provided information and insight on testing, etiology and further prognosis of AKI, leading to future of precision and personalized approach to AKI management. In this this article, we discussed the changing paradigms in AKI: from mechanisms to diagnostics, risk factors, and management of AKI.

Comparison between watchful waiting strategy and early initiation of renal replacement therapy in the critically ill acute kidney injury population: an updated systematic review and meta-analysis

BACKGROUND

The optimal timing of renal replacement therapy (RRT) initiation is debatable. Many articles in this field enrolled trials not based on acute kidney injury. The safety of the watchful waiting strategy has not been fully discussed, and late RRT initiation criteria vary across studies. The effect of early RRT initiation in the AKI population with high plasma neutrophil gelatinase-associated lipocalin (NGAL) has not been examined yet.

METHODS

In accordance with PRISMA guidelines, the PubMed, Embase, and Cochrane databases were systemically searched for randomized controlled trials (RCTs). Trials not conducted in the AKI population were excluded. Data of study characteristics, primary outcome (all-cause mortality), and related secondary outcomes [mechanical ventilation (MV) days, length of hospital stay, RRT days, and length of ICU stay] were extracted. The outcomes were compared between early and late RRT groups by estimating the pooled odds ratio (OR) for binary outcomes and the weighted mean difference for continuous outcomes. Prospective trials were also examined and analyzed using the same method.

RESULTS

Nine RCTs with 1938 patients were included. Early RRT did not provide a survival benefit (pooled OR, 0.88; 95% confidence interval [CI] 0.62-1.27). However, the early RRT group had significantly fewer MV days (pooled mean difference, - 3.98 days; 95% CI - 7.81 to - 0.15 days). Subgroup analysis showed that RCTs enrolling the surgical population (P = .001) and the AKI population with high plasma NGAL (P = .031) had favorable outcomes regarding RRT days in the early initiation group. Moreover, 6 of 9 RCTs were selected for examining the safety of the watchful waiting strategy, and no significant differences were found in primary and secondary outcomes between the early and late RRT groups.

CONCLUSIONS

Overall, early RRT initiation did not provide a survival benefit, but a possible benefit of fewer MV days was detected. Early RRT might also provide the benefit of shorter MV or RRT support in the surgical population and in AKI patients with high plasma NGAL. Depending on the conventional indication for RRT initiation, the watchful waiting strategy is safe on the basis of all primary and secondary outcomes.

Renal replacement therapy during extracorporeal membrane oxygenation

The use of extracorporeal membrane oxygenator (ECMO) has significantly increased in the past 20 years. There is a high incidence of acute kidney injury (AKI) in the group of patients on ECMO, with need for continuous renal replacement therapy (CRRT) in most of them. This article will review the basics of CRRT, its indications, the technical aspects of incorporating CRRT with ECMO circuit, data on clinical aspects, and outcomes.

Timing of Renal Replacement Therapy for Severe Acute Kidney Injury in Critically Ill Patients

Acute kidney injury (AKI) affects many ICU patients and is responsible for increased morbidity and mortality. Although lifesaving in many situations, renal replacement therapy (RRT) may be associated with complications, and the appropriate timing of its initiation is still the subject of intense debate. An early initiation strategy can prevent some metabolic complications, whereas a delayed one may allow for renal function recovery in some patients without need for this costly and potentially dangerous technique. For years, most of the knowledge on this issue stemmed from observational studies or small randomized controlled trials. Recent randomized controlled trials have indicated that a watchful waiting strategy (in the absence of life-threatening conditions such as severe hyperkalemia or pulmonary edema) during severe AKI allowed many patients to escape RRT and did not seem to adversely affect survival compared with a strategy of immediate RRT. In addition, data suggest that a delayed strategy may reduce the rate of complications (such as catheter infection) and favor renal function recovery. Ongoing studies will have to both confirm these conclusions and clarify to what extent the delay in initiating RRT can be prolonged. Pending those results, the bulk of evidence suggests that, in the absence of potential severe complications of AKI, delaying RRT is a valid and safe strategy that may also allow for considerable cost savings.

Hemofiltration in Patients with Severe Acute Pancreatitis (Review)

Questions regarding the application of extracorporeal detoxification to patients with severe acute pancreatitis have been considered. Hemodialysis, the historically first method of extracorporeal detoxification for such patients, has been also described in the review. Appropriateness of using renal replacement therapy methods and among them continued renal replacement therapy has been shown. Hemofiltration and hemodiafiltration technologies are described in detail including different modes of their application and the possibility of using various types of filters. Available data on hemofiltration for patients with severe acute pancreatitis have been analyzed. Great attention is paid to the unsolved aspects of hemofiltration in severe acute pancreatitis such as determining renal and extrarenal indices; time of starting hemofiltration; selection of volume replacement modes and a buffer system; procedure duration; anticoagulation measures, defining criteria to assess the adequacy of hemofiltration, state severity, and organ dysfunction degree. Further multicenter investigations are necessary to be able to assess the efficacy of the hemofiltration procedures on the basis of the thoroughly worked out and pathogenically grounded protocol using adequate control methods taking into consideration endogenic intoxication phases and intensity of the multiple organ failure syndrome.

Effects of early dialysis on the outcomes of critically ill patients with acute kidney injury: a systematic review and meta-analysis of randomized controlled trials

The appropriate timing for initiating renal replacement therapy (RRT) in critically ill patients with acute kidney injury (AKI) remains unknown. This meta-analysis aims to assess the efficacy of early initiation of RRT in critically ill patients with AKI. The Pubmed, Embase and Cochrane databases were searched up to August 13, 2019. Only randomized controlled trials (RCTs) comparing the effects of early and late RRT on AKI patients were included. The primary outcome was 28-day mortality. Eleven RCTs including 1131 and 1111 AKI patients assigned to early and late RRT strategies, respectively, were enrolled in this meta-analysis. The pooled 28-day mortality was 38.1% (431/1131) and 40.7% (453/1111) in the patients assigned to early and late RRT, respectively, with no significant difference between groups (risk ratio (RR), 0.95; 95% CI, 0.78-1.15, I2 = 63%). No significant difference was found between groups in terms of RRT dependence in survivors on day 28 (RR, 0.90; 95% CI, 0.67-1.25, I2 = 0%), and recovery of renal function (RR, 1.03; 95% CI, 0.89-1.19, I2 = 56%). The early RRT group had higher risks of catheter-related infection (RR, 1.7, 95% CI, 1.01-2.97, I2 = 0%) and hypophosphatemia (RR, 2.5, 95% CI, 1.25-4.99, I2 = 77%) than the late RRT group. In conclusion, an early RRT strategy does not improve survival, RRT dependence, or renal function recovery in critically ill patients with AKI in comparison with a late RRT strategy. However, clinicians should be vigilant because early RRT can carry higher risks of catheter-related infection and hypophosphatemia during dialysis than late RRT.

Early versus late initiation of renal replacement therapy for acute kidney injury in critically ill patients: A systematic review and meta-analysis

Background

Acute kidney injury is associated with high mortality, and is the most frequent complication encountered in patients residing in the intensive care unit. Although renal replacement therapy (RRT) is the standard of care for acute kidney injury, the optimal timing for initiation is still unknown.

Methods

We conducted a systemic review and meta-analysis of randomized controlled trials evaluating early versus late initiation of RRT in critically ill patients with acute kidney injury. We searched MEDLINE, Embase, and CENTRAL databases from inception to October 15, 2018. We screened studies and extracted data from published reported independently. The primary outcome was short-term mortality.

Results

A total of 2242 patients were included from 11 trials. No statistically significant effect was found for early versus late initiation of RRT on short-term mortality (risk ratio [RR] 0.99, 95% CI 0.84–1.17, p = 0.93) or long-term mortality (RR 0.98, 95% CI 0.85–1.13, p = 0.76). There were also no statistically significant effects on ICU length of stay, hospital length of stay, recovery of renal function, and renal replacement therapy dependence. Early initiation of RRT decreased the risk of metabolic acidosis (RR 0.65, 95% CI 0.43–0.99, p = 0.04), but increased the risk of hypotension (RR 1.24, 95% CI 1.08–1.43, p = 0.003).

Conclusions

In critically ill patients with acute kidney injury, early compared with late initiation of RRT is not associated with favorable mortality outcomes, although it appears to reduce the risk of metabolic acidosis.

Preemptive renal replacement therapy in post-cardiotomy cardiogenic shock patients: a historically controlled cohort study

BACKGROUND

The aim of the study was to evaluate whether the preemptive renal replacement therapy (RRT) might improve outcomes in post-cardiotomy cardiogenic shock (PCCS) patients.

METHODS

In Period A (September 2014-April 2016), patients with PCCS received RRT, depending on conventional indications or bedside attendings. In Period B (May 2016-November 2017), the preemptive RRT strategy was implemented in all PCCS patients in our intensive care unit. The goal-directed RRT was applied for the RRT patients. The hospital mortality and renal recovery were compared between the two periods.

RESULTS

A total of 155 patients (76 patients in Period A and 79 patients in Period B) were ultimately enrolled in this study. There were no significant differences in demographic characteristics and intraoperative and postoperative parameters between the two groups. The duration between surgery and RRT initiation was significantly shorter in Period B than in Period A [23 (17, 66) vs. 47 (20, 127) h, P<0.01]. The hospital mortality in Period B was significantly lower than that in Period A (38.0% vs. 59.2%, P<0.01). There were fewer patients with no renal recovery in Period B (4.1% vs. 19.4%, P=0.026). Patients in Period B displayed a significantly shorter time to completely renal recovery (12±15 vs. 25±15 d, P<0.05).

CONCLUSIONS

Among PCCS patients, preemptive RRT compared with conventional initiation of RRT reduced mortality in hospital and also led to faster and more frequent recovery of renal function. Our preliminary study supposed that preemptive initiation of RRT might be an effective approach to PCCS with acute kidney injury (AKI).

Perioperative renal protection

PURPOSE OF REVIEW

The present article reviews the recent literature on the main aspects of perioperative acute kidney injury (AKI).

RECENT FINDINGS

AKI occurs in 1 in every 10 surgical patients, with cardiac, orthopedic, and major abdominal surgeries being the procedures associated with the highest risk. Overall, complex operations, bleeding, and hemodynamic instability are the most consistent procedure-related risk factors for AKI. AKI increases hospital stay, mortality, and chronic kidney disease, gradually with severity. Furthermore, delayed renal recovery negatively impacts on patients' outcomes. Cell cycle arrest biomarkers seem promising to identify high-risk patients who may benefit from the bundles recommended by the Kidney Disease: Improving Global Outcomes guidelines. Hemodynamic management using protocol-based administration of fluids and vasopressors helps reducing AKI. Recent studies have highlighted the benefit of personalizing the blood pressure target according to the patient's resting reference, and avoiding both hypovolemia and fluid overload. Preliminary research has reported encouraging renoprotective effects of angiotensin II and nitric oxide, which need to be confirmed. Moreover, urinary oxygenation monitoring appears feasible and a fair predictor of postoperative AKI.

SUMMARY

AKI remains a frequent and severe postoperative complication. A personalizedmulticomponent approach might help reducing the risk of AKI and improving patients' outcomes.

Timing of Renal Support and Outcome of Septic Shock and Acute Respiratory Distress Syndrome. A Post Hoc Analysis of the AKIKI Randomized Clinical Trial

RATIONALE

The optimal strategy for initiation of renal replacement therapy (RRT) in patients with severe acute kidney injury in the context of septic shock and acute respiratory distress syndrome (ARDS) is unknown.

OBJECTIVES

To examine the effect of an early compared with a delayed RRT initiation strategy on 60-day mortality according to baseline sepsis status, ARDS status, and severity.

METHODS

Post hoc analysis of the AKIKI (Artificial Kidney Initiation in Kidney Injury) trial.

MEASUREMENTS AND MAIN RESULTS

Subgroups were defined according to baseline characteristics: sepsis status (Sepsis-3 definition), ARDS status (Berlin definition), Simplified Acute Physiology Score 3 (SAPS 3), and Sepsis-related Organ Failure Assessment (SOFA). Of 619 patients, 348 (56%) had septic shock and 207 (33%) had ARDS. We found no significant influence of the baseline sepsis status (P = 0.28), baseline ARDS status (P = 0.94), and baseline severity scores (P = 0.77 and P = 0.46 for SAPS 3 and SOFA, respectively) on the comparison of 60-day mortality according to RRT initiation strategy. A delayed RRT initiation strategy allowed 45% of patients with septic shock and 46% of patients with ARDS to escape RRT. Urine output was higher in the delayed group. Renal function recovery occurred earlier with the delayed RRT strategy in patients with septic shock or ARDS (P < 0.001 and P = 0.003, respectively). Time to successful extubation in patients with ARDS was not affected by RRT strategy (P = 0.43).

CONCLUSIONS

Early RRT initiation strategy was not associated with any improvement of 60-day mortality in patients with severe acute kidney injury and septic shock or ARDS. Unnecessary and potentially risky procedures might often be avoided in these fragile populations. Clinical trial registered with www.clinicaltrials.gov (NCT 01932190).

Effect of High-Volume Hemofiltration in Critically Ill Patients: A Systematic Review and Meta-Analysis

Background

Studies have been carried out to assess the efficacy of high-volume hemofiltration (HVHF) among critically ill patients. However, it is currently unclear whether HVHF is really valuable in critically ill patients.

Material/Methods

Randomized controlled trials evaluating HVHF for critically ill adult patients were included in this analysis. Three databases were searched up to July 27, 2018. The relative risk (RR), mean difference (MD), and 95% confidence intervals (CI) were determined.

Results

Twenty-one randomized controlled trials were included in this analysis. Overall, HVHF was associated with lower mortality compared with control measures (RR=0.88, 95% CI=0.81 to 0.96, P=0.004) in critically ill patients. Sub-analysis revealed HVHF reduced mortality in sepsis and acute respiratory distress syndrome patients, but no similar effect in other diseases. HVHF decreased levels of plasma tumor necrosis factor and interleukin 6. The heart rate of the HVHF group after treatment was slower than the control group, while we found higher mean arterial pressure in the HVHF group, but oxygenation index was not significantly different between the two groups. HVHF had no remarkable influence on acute physiological and chronic health evaluation score (APACHE II score) compared with the control group.

Conclusions

HVHF might be superior to conventional therapy in critically ill patients.

Early initiation of renal replacement therapy in critically ill patients: a meta-analysis of randomized clinical trials

Background

Acute kidney injury (AKI) is strongly associated with high morbidity and mortality of critically ill patients. In the last years several different biological markers with higher sensitivity and specificity for the occurrence of renal impairment have been developed in order to promptly recognize and treat AKI. Nonetheless, their potential role in improving patients’ outcome remains unclear since the effectiveness of an “earlier” initiation of renal replacement therapy (RRT) is still debated. Since one large, high-quality randomized clinical trial has been recently pubblished, we decided to perform a meta-analysis of all the RCTs ever performed on “earlier” initiation of RRT versus standard RRT in critically ill patients with AKI to evaluate its effect on major outcomes.

Methods

Pertinent studies were independently searched in BioMedCentral, PubMed, Embase, and Cochrane Central Register of clinical trials. The following inclusion criteria were used: random allocation to treatment (“earlier” initiation of RRT versus later/standard initiation); critically ill patients.

Results

Ten trials randomizing 2214 patients, 1073 to earlier initiation of RRT and 1141 to later initiation were included. No difference in mortality (43.3% (465 of 1073) for those receiving early RRT and 40.8% (466 of 1141) for controls, p = 0.97) and survival without dependence on RRT (3.6% (34 of 931) for those receiving early RRT and 4.2% (40 of 939) for controls, p = 0.51) were observed in the overall population. On the contrary, early initiation of RRT was associated with a significant reduction in hospital length of stay. No differences in occurrence of adverse events were observed.

Conclusions

Our study suggests that early initiation of RRT in critically ill patients with AKI does not provide a clinically relevant advantage when compared with standard/late initiation.

Electronic supplementary material

The online version of this article (10.1186/s12871-019-0733-7) contains supplementary material, which is available to authorized users.

Impact of renal replacement therapy on survival in patients with KDIGO stage 3 acute kidney injury: A propensity score matched analysis

AIM

To investigate the impact of renal replacement therapy (RRT) on 90-day mortality in critically ill patients suffering from KDIGO stage 3 acute kidney injury (AKI) with or without life-threatening complications using propensity score matching analysis.

METHODS

We conducted a retrospective analysis of critically ill adult patients with KDIGO Stage 3 AKI with or without RRT during ICU stay between 1/1/2011-31/12/2013. Cox regression analysis and propensity score matching methods were used to determine predictors for 90-day mortality.

RESULTS

Among 661 patients, 50.5% received RRT. The unadjusted 90-day mortality rate was 42.5% and 54.1% in patients who had or had not received RRT, respectively. After adjustment with propensity score based on the probability of receiving RRT, the cox regression analysis showed that RRT was associated with a lower 90-day mortality (p<0.001). Among 322 propensity-matched pairs, RRT was associated with lower ICU (23.6% vs. 39.8%, p=0.002), hospital (33.5% vs. 55.9%, p<0.001) and 90-day mortality (34.2% vs. 58.4%, p<0.001), and a higher 90-day renal recovery rate (57.8% vs. 45.3% full recovery, p=0.026) compared with no RRT. When an alternate propensity model was used, the benefits associated with RRT were very similar, except 90-day renal recovery became insignificant.

CONCLUSION

Our observational study found that in critically ill patients with KDIGO Stage 3 AKI, RRT may be associated with lower 90-day mortality. The benefit of RRT on renal recovery was less prominent. Medical futility and practice variations may complicate study interpretation. To avoid these limitations, large-scale multicenter, non-observational study is recommended.

Continuous blood purification for severe acute pancreatitis: A systematic review and meta-analysis

BACKGROUND

The incidence of acute pancreatitis (AP) is rising around the world, thus further increasing the burden on healthcare services. Approximately 20% of AP will develop severe acute pancreatitis (SAP) with persistent organ failure (>48 h), which is the leading cause of high mortality. To date, there is no specific drug in treating SAP, and the main treatment is still based on supportive care. However, some clinical control studies regarding the superiority of continuous blood purification (CBP) has been published recently. Therefore, we conducted a systematic review and meta-analysis to evaluate the efficacy of CBP in SAP treatment.

METHODS

Four databases (Medline, SinoMed, EMBASE, and Cochrane Library) were searched for eligible studies from 1980 to 2018 containing a total of 4 randomized controlled trials and 8 prospective studies.

RESULTS

After the analysis of data amenable to polling, significant advantages were found in favor of the CBP approach in terms of Acute Physiology and Chronic Health Evaluation II (APACHE II) score (WMD = -3.00,95%CI = -4.65 to -1.35), serum amylase (WMD = -237.14, 95% CI = -292.77 to 181.31), serum creatinine (WMD = -80.54,95%CI = 160.17 to -0.92), length of stay in the ICU (WMD = -7.15,95%CI = -9.88 to -4.43), and mortality (OR = 0.60, 95%CI = 0.38-0.94). No marked differences were found in terms of C-reactive protein (CRP), alamine aminotransferase (ALT) and length of hospital stay (LOS).

CONCLUSION

Compared with conventional treatment, CBP remedy evidently improved clinical outcomes, including reduced incidence organ failure, decreased serum amylase, APACHE II score, length of stay in the ICU and lower mortality rate, leading us to conclude that it is a safer treatment option for SAP. Furthermore, relevant multicenter RCTs are required to prove these findings.

New modes of continuous renal replacement therapy using a refiltering technique to reduce micronutrient loss

INTRODUCTION

Micronutrient depletion is a major drawback of high-dose continuous renal replacement therapy (CRRT). We tested two novel CRRT modes, double-filtration hemofiltration (DHF) and dialysate-recycling hemodiafiltration (DHDF), aimed at reducing micronutrient loss while maintaining a high clearance rate of midsized solutes comparable to that of high-volume hemofiltration (HVHF).

METHODS

Forty patients with renal failure requiring CRRT were randomly assigned to receive predilutional standard-volume hemofiltration (SVHF, effluent rate 35 mL/kg/h), predilutional HVHF (100 mL/kg/h), DHF (35 mL/kg/h), and DHDF (30 mL/kg/h). In the two novel modes of CRRT, part of the high-volume primary effluent fluid produced by a high-flux filter (AV600S) was refiltered by two low-flux filters (15 L) for recycling as replacement fluid in DHF and dialysate in DHDF, while the remainder was discarded as final effluent fluid. Specimens were collected for measurement of trace elements, folic acid, amino acids (AAs), β2-microglobulin, cystatin C, and creatinine and for calculation of solute clearance.

FINDINGS

The clearance of 17 AAs, phosphorus, folic acid, copper, and zinc by DHF and DHDF was much lower than that by HVHF and comparable to that by SVHF. The estimated amount of AA loss by SVHF, HVHF, DHF, and DHDF was 10.3 (7.2-13.4) g/d, 22.1 (17.8-24.0) g/d, 10.6 (8.6-14.0) g/d, and 10.0 (8.6-11.4) g/d, respectively. Clearance of cystatin C and β2-microglobulin by DHF and DHDF was much greater than that by SVHF and equal to that by HVHF.

DISCUSSION

Compared to HVHF, DHF, and DHDF have an equal capacity for removal of large solutes but show substantially reduced micronutrient loss.

Timing of renal replacement therapy initiation for acute kidney injury

BACKGROUND

Acute kidney injury (AKI) is a common condition among patients in intensive care units (ICUs), and is associated with high death. Renal replacement therapy (RRT) is a blood purification technique used to treat the most severe forms of AKI. The optimal time to initiate RRT so as to improve clinical outcomes remains uncertain.This review complements another Cochrane review by the same authors: Intensity of continuous renal replacement therapy for acute kidney injury.

OBJECTIVES

To assess the effects of different timing (early and standard) of RRT initiation on death and recovery of kidney function in critically ill patients with AKI.

SEARCH METHODS

We searched the Cochrane Kidney and Transplant's Specialised Register to 23 August 2018 through contact with the Information Specialist using search terms relevant to this review. Studies in the Register are identified through searches of CENTRAL, MEDLINE, and EMBASE, conference proceedings, the International Clinical Trials Register (ICTRP) Search Portal and ClinicalTrials.gov. We also searched LILACS to 11 September 2017.

SELECTION CRITERIA

We included all randomised controlled trials (RCTs). We included all patients with AKI in ICU regardless of age, comparing early versus standard RRT initiation. For safety and cost outcomes we planned to include cohort studies and non-RCTs.

DATA COLLECTION AND ANALYSIS

Data were extracted independently by two authors. The random-effects model was used and results were reported as risk ratios (RR) for dichotomous outcomes and mean differences (MD) for continuous outcomes, with 95% confidence intervals (CI).

MAIN RESULTS

We included five studies enrolling 1084 participants. Overall, most domains were assessed as being at low or unclear risk of bias. Compared to standard treatment, early initiation may reduce the risk of death at day 30, although the 95% CI does not rule out an increased risk (5 studies, 1084 participants: RR 0.83, 95% CI 0.61 to 1.13; I2 = 52%; low certainty evidence); and probably reduces the death after 30 days post randomisation (4 studies, 1056 participants: RR 0.92, 95% CI 0.76 to 1.10; I2= 29%; moderate certainty evidence); however in both results the CIs included a reduction and an increase of death. Earlier start may reduce the risk of death or non-recovery kidney function (5 studies, 1076 participants: RR 0.83, 95% CI 0.66 to 1.05; I2= 54%; low certainty evidence). Early strategy may increase the number of patients who were free of RRT after RRT discontinuation (5 studies, 1084 participants: RR 1.13, 95% CI 0.91 to 1.40; I2= 58%; low certainty evidence) and probably slightly increases the recovery of kidney function among survivors who discontinued RRT after day 30 (5 studies, 572 participants: RR 1.03, 95% CI 1.00 to 1.06; I2= 0%; moderate certainty evidence) compared to standard; however the lower limit of CI includes the null effect. Early RRT initiation increased the number of patients who experienced adverse events (4 studies, 899 participants: RR 1.10, 95% CI 1.03 to 1.16; I2 = 0%; high certainty evidence). Compared to standard, earlier RRT start may reduce the number of days in ICU (4 studies, 1056 participants: MD -1.78 days, 95% CI -3.70 to 0.13; I2 = 90%; low certainty evidence), but the CI included benefit and harm.

AUTHORS' CONCLUSIONS

Based mainly on low quality of evidence identified, early RRT may reduce the risk of death and may improve the recovery of kidney function in critically patients with AKI, however the 95% CI indicates that early RRT might worsen these outcomes. There was an increased risk of adverse events with early RRT. Further adequate-powered RCTs using appropriate criteria to define the optimal time of RRT are needed to reduce the imprecision of the results.