Earlier versus later initiation of renal replacement therapy among critically ill patients with acute kidney injury: a systematic review and meta-analysis of randomized controlled trials

Impact of Precision in Staging Acute Kidney Injury and Chronic Kidney Disease on Treatment Outcomes: An Observational Study

(1) Background: "Kidney Disease: Improving Global Outcomes" (KDIGO) provides guidelines for identifying the stages of acute kidney injury (AKI) and chronic kidney disease (CKD). A data-driven rule-based engine was developed to determine KDIGO staging compared to KD-related keywords in discharge letters. (2) Methods: To assess potential differences in outcomes, we compare the patient subgroups with exact KDIGO staging to imprecise or missing staging for all-cause mortality, in-hospital mortality, selection bias and costs by applying Kaplan-Meier analysis and the Cox proportional hazards regression model. We analysed 63,105 in-patient cases from 2016 to 2023 at a tertiary hospital with AKI, CKD and acute-on-chronic KD. (3) Results: Imprecise and missing CKD staging were associated with an 85% higher risk of all-cause and in-hospital mortality (CI: 1.7 to 2.0 and 1.66 to 2.03, respectively) compared to exact staging for any given disease status; imprecise or missing AKI staging increased in-hospital mortality risk by 56% and 57% (CI: 1.43 to 1.70 and 1.37 to 1.81, respectively) in patients with AKI. (4) Conclusions: Exact staging is associated with better outcomes in KD management. Our study provides valuable insight into potential quality and outcome improvements and lower costs, considering elderly patients, women and patients with acute-on-chronic KD as the most vulnerable.

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.

Elevated strong ion gap: A predictor of the initiation of continuous renal replacement therapy in acute kidney injury

BACKGROUND

There is no optimal timing for continuous renal replacement therapy (CRRT) in acute kidney injury (AKI). AKI is a reason for the increased unmeasured anions, which refers to the increased organic acids in the blood, and they can be detected by calculating strong ion gap (SIG). SIG level at the moment of the AKI diagnosis may be a predictor for the initiation of CRRT.

METHODS

Patients who were diagnosed with AKI in the first week of the intensive care unit (ICU) period were included in this prospective observational study. At the moment of the AKI diagnosis, blood gas samples were recorded, and SIG was calculated.

RESULTS

The median level of SIG at the moment of the AKI diagnosis of CRRT (+) patients was significantly higher than CRRT (-) patients (7.4 and 3.2 mmol L-1, respectively). In the multivariate Cox regression analysis, the likelihood of the initiation of CRRT was increased 1.16-fold (1.01-1.33) and 4.0-fold (1.9-8.7) by only 1 mmol L-1 increases in SIG and SIG ≥6 mmol L-1 at the moment of AKI diagnosis, respectively (p = 0.035 and p < 0.001).

CONCLUSIONS

Increased SIG at the moment of the AKI diagnosis in patients with AKI may be a predictive marker to initiate CRRT.

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.

Effect of continuous hemofiltration on severe acute pancreatitis with different intra-abdominal pressure: A cohort study

BACKGROUND

The clinical efficacy and timing of continuous veno-venous hemofiltration (CVVH) in the treatment of severe acute pancreatitis (SAP) remain uncertain. In this prospective cohort study, patients with SAP were classified according to intra-abdominal pressure (IAP).

METHODS

Seventy-four patients with SAP admitted to the intensive care unit were randomly divided into group A (IAP ≥20 mm Hg) and group B (with IAP ≤20 mm Hg). Then, according to whether CVVH was administered or not, groups A and B were divided into 4 subgroups: group A1 and B1 (non-CVVH treatment), group A2 and B2 (CVVH treatment). Changes in clinical and laboratory indicators were recorded before and on the seventh day after treatment, and clinical outcomes were analyzed.

RESULTS

Before treatment, there was no significant difference in general conditions between subgroups A1 and A2, and between subgroups B1 and B2. After CVVH treatment, the indicators recorded in group A2 were significantly improved compared to those in group A1 (P < .05). In group A2, the 28 day operation rate was lower (P < .05), as mechanical ventilation, gastric decompression, and intensive care unit treatment time were shorter (P < .05). However, there was no statistically significant difference in any of the above indicators between subgroups B (P > .05). Groups A2 and B2 had more days of negative fluid balance within 1 week of admission than groups A1 and B1 (P < .05).

CONCLUSIONS

For SAP, patients with IAP ≥20 mm Hg can benefit from treatment with CVVH, but for patients with IAP ≤20 mm Hg, the efficacy is not clear, and monitoring IAP may be an indicator to decide whether or when to initiate CVVH. Negative fluid balance caused by CVVH treatment may be one of the reasons for the benefit of this group of patients.

When and why to start continuous renal replacement therapy in critically ill patients with acute kidney injury

Acute kidney injury (AKI) is a common condition in critically ill patients, and may contribute to significant medical, social, and economic consequences, including death. Although there have been advances in medical technology, including continuous renal replacement therapy (CRRT), the mortality rate of AKI is high, and there is no fundamental treatment that can reverse disease progression. The decision to implement CRRT is often subjective and based primarily on the clinician’s judgment without consistent and concrete guidelines or protocols regarding when to initiate and discontinue CRRT and how to manage complications. Recently, several randomized controlled trials addressing the initiation of renal replacement therapy in critically ill patients with AKI have been completed, but clinical application of the findings is limited by the heterogeneity of the objectives and research designs. In this review, the advantages and disadvantages of CRRT initiation, clinical guideline recommendations, and the results of currently published clinical trials and meta-analyses are summarized to guide patient care and identify future research priorities.

A Scoring Model with Simple Clinical Parameters to Predict Successful Discontinuation of Continuous Renal Replacement Therapy

BACKGROUND

Continuous renal replacement therapy (CRRT) is the standard treatment for severe acute kidney injury in critically ill patients. However, a practical consensus for discontinuing CRRT is lacking. We aimed to develop a prediction model with simple clinical parameters for successful discontinuation of CRRT.

METHODS

Adult patients who received CRRT at Samsung Medical Center from 2007 to 2017 were included. Patients with preexisting ESRD and patients who progressed to ESRD within 1 year or died within 7 days after CRRT were excluded. Successful discontinuation of CRRT was defined as no requirement for renal replacement therapy for 7 days after discontinuing CRRT. Patients were assigned to either a success group or failure group according to whether discontinuation of CRRT was successful or not.

RESULTS

A total of 1,158 patients were included in the final analyses. The success group showed greater urine output on the day before CRRT discontinuation (D-1) and the discontinuation day (D0). Multivariable analysis identified that urine output ≥300 mL on D-1, and mean arterial pressure 50∼78 mm Hg, serum potassium <4.1 mmol/L, and BUN <35 mg/dL (12.5 mmol/L) on D0 were predictive factors for successful discontinuation of CRRT. A scoring system using the 4 variables above (area under the receiver operating curve: 0.731) was developed.

CONCLUSIONS

Scoring system composed of urine output ≥300 mL/day on D-1, and adequate blood pressure, serum potassium <4.1 mmol/L, and BUN <35 mg/dL (12.5 mmol/L) on D0 was developed to predict successful discontinuation of CRRT.

Renal replacement therapy in critically ill patients with acute kidney injury: 2020 nephrologist's perspective

Renal replacement therapies (RRT) as support for acute kidney injury in critically ill patients have become a routine and essential practice in their management, resulting in the widespread use of various techniques among these patients, such as intermittent hemodialysis (IHD), extended hemodialysis and continuous RRT (CRRT). In this review we aim to summarize current evidence of indication, choice of modality, timing of initiation, dosing and technical aspects of RRT. We carried out a narrative review based on guidelines, consensus documents by main working groups and the latest relevant clinical trials on RRT in the critically ill. We did not find enough evidence of any RRT modality having superior benefits in terms of patient survival, length of intensive care unit/hospital stay or renal outcomes among critically ill patients, in spite of optimization of clinical indication, modality, timing of initiation and intensity of initial therapy. This is still a controverted matter, since only early start of high-flux CRRT has been proven beneficial over IHD among hemodynamically unstable postoperative patients. Our objective is to portrait current RRT practices in multidisciplinary management of critically ill patients by intensive care and nephrology professionals. Implication of a nephrologist in the assessment of hemodynamic status, coexisting medical conditions, renal outcome expectations and management of resources could potentially have benefits at the time of RRT selection and troubleshooting.

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.

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.

Accelerated versus standard initiation of renal replacement therapy for critically ill patients with acute kidney injury: a systematic review and meta-analysis of RCT studies

BACKGROUND

Acute kidney injury (AKI) is a common yet possibly fatal complication among critically ill patients in intensive care units (ICU). Although renal replacement therapy (RRT) is an important supportive management for severe AKI patients, the optimal timing of RRT initiation for these patients is still unclear.

METHODS

In this systematic review, we searched all relevant randomized controlled trials (RCTs) that directly compared accelerated with standard initiation of RRT from PUBMED, MEDLINE, EMBASE, and Cnki.net published prior to July, 20, 2020. We extracted study characteristics and outcomes of being free of dialysis, dialysis dependence and mortality. We rated the certainty of evidence according to Cochrane methods and the GRADE approach.

RESULTS

We identified 56 published relevant studies from 1071 screened abstracts. Ten RCTs with 4753 critically ill AKI patients in intensive care unit (ICU) were included in this meta-analysis. In our study, accelerated and standard RRT group were not associated with all-cause mortality (log odds-ratio [OR]: - 0.04, 95% confidence intervals [CI] - 0.16 to 0.07, p = 0.46) and free of dialysis (log OR: - 0.03, 95% CI - 0.14 to 0.09, p = 0.65). In the subgroup analyses, accelerated RRT group was significantly associated with lower risk of all-cause mortality in the surgical ICU and for those who received continuous renal replacement therapy (CRRT). In addition, patients in these two subgroups had higher chances of being eventually dialysis-free. However, accelerated initiation of RRT augmented the risk of dialysis dependence in the subgroups of patients treated with non-CRRT modality and whose Sequential Organ Failure Assessment (SOFA) score were more than 11.

CONCLUSIONS

In this meta-analysis, critically ill patients with severe AKI would benefit from accelerated RRT initiation regarding all-cause mortality and being eventually free of dialysis only if they were surgical ICU patients or if they underwent CRRT treatment. However, the risk of dialysis dependence was increased in the accelerated RRT group when those patients used non-CRRT modality or had high SOFA scores. All the literatures reviewed in this study were highly heterogeneous and potentially subject to biases. Trial registration CRD42020201466, Sep 07, 2020. https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=201466 .

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.

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.

Prescription of CRRT: a pathway to optimize therapy

Severe acute kidney injury (AKI), especially when caused or accompanied by sepsis, is associated with prolonged hospitalization, progression to chronic kidney disease (CKD), financial burden, and high mortality rate. Continuous renal replacement therapy (CRRT) is a predominant form of renal replacement therapy (RRT) in the intensive care unit (ICU) due to its accurate volume control, steady acid-base and electrolyte correction, and achievement of hemodynamic stability. This manuscript reviews the different aspects of CRRT prescription in critically ill patients with severe AKI, sepsis, and multiorgan failure in ICU. These include the choice of CRRT versus Intermittent and extended hemodialysis (HD), life of the filter/dialyzer including assessment of filtration fraction, anticoagulation including regional citrate anticoagulation (RCA), prescribed versus delivered CRRT dose, vascular access management, timing of initiation and termination of CRRT, and prescription in AKI/sepsis including adsorptive methods of removing endotoxins and cytokines.

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.

Continuous renal replacement therapy in elderly with acute kidney injury

The objective of this article is to raise awareness among physicians of the increasing incidence of acute kidney injury in the elderly population and the utility of continuous renal replacement therapy (CRRT) in its management. While CRRT is frequently applied in younger patients, its use in elderly patients is less frequent, for various reasons, including resistance to such an aggressive intervention from the family and the healthcare team. However, predictors of prognosis have been identified and some studies have concluded that advanced age is not associated with poor outcomes. Decisions regarding management are more complex when dealing with the elderly but like very other patient, the approach should be patient- centered.

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).

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.

Clinical Features and Indications Associated with Mortality in Continuous Renal Replacement Therapy for Pediatric Patients

OBJECTIVES

To identify prognostic factors and indications in patients receiving continuous renal replacement therapy (CRRT) in the pediatric intensive care unit (PICU), and to demonstrate their effect on mortality.

METHODS

A total of 63 patients admitted between 2011 and 2014 were included in the study. The demographic information, pediatric risk of mortality (PRISM) scores, vasoactive-inotropic score, indication for CRRT, time of starting CRRT, presence of fluid overload, durations of CRRT, and pediatric intensive care unit (PICU) stay were compared between survivors and non-survivors.

RESULTS

The overall rate of survival was 69,8%. The most common indication for CRRT was fluid overload (31.7%) followed by acute attacks of metabolic diseases (15.9%), and resistant metabolic acidosis (15.9%). The median duration of CRRT was 58 (IQR 24-96) h. The most common CRRT modality was continuous venovenous hemodiafiltration. The CRRT modality was not different between survivors and nonsurvivors. Sepsis, as the diagnosis for admission to intensive care unit was significantly related to decreased survival when compared to acute kidney injury and acute attacks of metabolic diseases. Patients with fluid overload had significantly increased rate of death, CRRT duration, use of mechanical ventilation, and PICU stay.

CONCLUSIONS

The CRRT, can be effectively used for removal of fluid overload, treatment of acute attacks of metabolic diseases, and other indications in critically ill pediatric patients. It has a positive effect on mortality in high-risk PICU patients. This treatment modality can be used more frequently in pediatric intensive care unit with improved patient outcomes, and should be focused on starting therapy in early stages of fluid overload.

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.

Impact of Early versus Late Initiation of Renal Replacement Therapy in Patients with Cardiac Surgery-Associated Acute Kidney Injury: Meta-Analysis with Trial Sequential Analysis of Randomized Controlled Trials

Background

Previous studies have examined the effect of the initiation time of renal replacement therapy (RRT) in patients with cardiac surgery-associated acute kidney injury (CSA-AKI), but the findings remain controversial. The aim of this meta-analysis was to systematically and quantitatively compare the impact of early versus late initiation of RRT on the outcome of patients with CSA-AKI.

Methods

Four databases (PubMed, the Cochrane Library, ISI Web of Knowledge, and Embase) were systematically searched from inception to June 2018 for randomized clinical trials (RCTs). Two investigators independently performed the literature search, study selection, data extraction, and quality evaluation. Meta-analysis and trial sequential analysis (TSA) were used to examine the impact of RRT initiation time on all-cause mortality (primary outcome). The Grading of Recommendations Assessment Development and Evaluation (GRADE) was used to evaluate the level of evidence.

Results

We identified 4 RCTs with 355 patients that were eligible for inclusion. Pooled analyses indicated no difference in mortality for patients receiving early and late initiation of RRT (relative risk [RR] = 0.61, 95% confidence interval [CI] = 0.33 to 1.12). However, the results were not confirmed by TSA. Similarly, early RRT did not reduce the length of stay (LOS) in the intensive care unit (ICU) (mean difference [MD] = -1.04; 95% CI = -3.34 to 1.27) or the LOS in the hospital (MD = -1.57; 95% CI = -4.62 to 1.48). Analysis using GRADE indicated the certainty of the body of evidence was very low for a benefit from early initiation of RRT.

Conclusion

Early initiation of RRT had no beneficial impacts on outcomes in patients with CSA-AKI. Future larger and more adequately powered prospective RCTs are needed to verify the benefit of reduced mortality associated with early initiation of RRT.

Trial Registration

This trial is registered with PROSPERO registration number CRD42018084465, registered on 11 February 2018.

Timing of Renal Replacement Therapy in Acute Kidney Injury: Shedding New Light on an Old Controversy

Critically ill patients with severe acute kidney injury (AKI-D) require renal replacement therapy (RRT) increasingly. However, the optimal timing of initiation of RRT for non-life-threatening indications of AKI remains unknown. There is a debate as to whether different philosophies of RRT initiation (early vs. delayed) confer a survival benefit. Lowering the threshold for RRT initiation, however, inevitably leads to more critically ill patients receiving unnecessary RRT. The relevant proportion of nonprogressing early stage AKI patients with spontaneous kidney recovery is a matter of severe concern because RRT has potentially lethal complications and is expensive. Moreover, these patients should be excluded from randomized trials. The furosemide stress test in critically ill patients with early stages of AKI serves as a novel tubular function test to identify those patients with severe and progressive AKI-D. Future trials to validate findings of a promising pilot study are warranted.

Factors that influenced undergoing renal replacement therapy and survival in children with acute kidney injury

AIM

Acute kidney injury (AKI) is an important clinical condition that is associated with increased mortality and morbidity. This study was performed to identify the factors that influence AKI stage, undergoing renal replacement therapy (RRT) and mortality.

METHODS

This study was retrospectively conducted on 219 children with AKI who had been referred to the paediatric nephrology division of Dr Sami Ulus Teaching Hospital during their inpatient treatment from 2008 to 2012. AKI was defined using pRIFLE criteria.

RESULTS

From the 219 enrolled patients, 131 were identified as having AKI at the time of hospital admission. Infant age group was the largest group. RRT was performed in 68 patients. Median RRT initiation time was 1.5 day (0-2) and the mortality increased significantly when RRT initiation time was >1 day. The likelihood of undergoing RRT was higher for patients who were younger, who were managed in PICU and who had intrinsic type of AKI. pRIFLE stage and AKI place did not influence the likelihood of undergoing RRT. Overall mortality was 26.9%. In log-rank tests, factors influencing survival were younger age, being treated in PICU, developing AKI during inpatient treatment, having a comorbid condition and undergoing RRT. pRIFLE stage did not influence survival. In the logistic regression model, factors associated with mortality included younger age, undergoing RRT and having AKI during inpatient treatment. Having underlying disease and being managed in PICU did not influence the likelihood of death.

CONCLUSION

Acute kidney injury is an important condition in all hospitalized patients. More studies and interventions are needed on this topic to identify, treat and prevent AKI.

Noteworthy Literature published in 2017 for Cardiac Critical Care

In 2017, many high-impact articles appeared in the literature. This is the third edition of an annual review of articles related to postoperative cardiac critical care that may affect the cardiac anesthesiologist. This year explores vasopressor and inotropic support, timing of renal replacement therapy, management of postoperative respiratory insufficiency, and targeted temperature therapy.

An isolated elevation in blood urea level is not 'uraemia' and not an indication for renal replacement therapy in the ICU

The decision to initiate renal replacement therapy (RRT) and the optimal timing for commencement is a difficult decision faced by clinicians when treating acute kidney injury (AKI) in the intensive care setting. Without clinically significant ureamic symptoms or emergent indications (electrolyte abnormalities, volume overload) the timing of RRT initiation remains contentious and inconsistent across health providers. Current trends of initiating RRT in the ICU are often based on isolated blood urea levels without clear guidelines demonstrating an upper limit for treatment. Although the appropriate upper limit remains unclear, it is reasonable to conclude that a blood urea level less than 40 mmol/L is not in itself an indication for RRT, especially in the absence of supporting evidence of kidney impairment (anuria, elevated serum creatinine), presenting a welcome reminder to treat the patient and not a number.

Optimal timing of renal replacement therapy initiation in acute kidney injury: the elephant felt by the blindmen?

Renal replacement therapy (RRT) is a key component in the management of severe acute kidney injury (AKI) in critically ill patients. Many cohort studies, meta-analyses, and two recent large randomized prospective trials which evaluated the relationship between the timing of RRT initiation and patient outcome remain inconclusive due to substantial differences in study design, patient population, AKI definition, and RRT indication. A cause-specific diagnosis of AKI based on current staging criteria plus a sensitive biomarker (panel) that allows creating a homogeneous study population is definitely needed to assess the impact of early versus late initiation of RRT on patient outcome.