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

APASL clinical practice guidelines on the management of acute kidney injury in acute-on-chronic liver failure

Acute-on-chronic liver failure (ACLF) is a syndrome that is characterized by the rapid development of organ failures predisposing these patients to a high risk of short-term early death. The main causes of organ failure in these patients are bacterial infections and systemic inflammation, both of which can be severe. For the majority of these patients, a prompt liver transplant is still the only effective course of treatment. Kidneys are one of the most frequent extrahepatic organs that are affected in patients with ACLF, since acute kidney injury (AKI) is reported in 22.8-34% of patients with ACLF. Approach and management of kidney injury could improve overall outcomes in these patients. Importantly, patients with ACLF more frequently have stage 3 AKI with a low rate of response to the current treatment modalities. The objective of the present position paper is to critically review and analyze the published data on AKI in ACLF, evolve a consensus, and provide recommendations for early diagnosis, pathophysiology, prevention, and management of AKI in patients with ACLF. In the absence of direct evidence, we propose expert opinions for guidance in managing AKI in this very challenging group of patients and focus on areas of future research. This consensus will be of major importance to all hepatologists, liver transplant surgeons, and intensivists across the globe.

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.

Meaning and Management of Perioperative Oliguria

Perioperative oliguria is an alarm signal. The initial assessment includes closer patient monitoring, evaluation of volemic status, risk-benefit of fluid challenge or furosemide stress test, and investigation of possible perioperative complications.

The effects of timing onset and progression of AKI on the clinical outcomes in AKI patients with sepsis: a prospective multicenter cohort study

BACKGROUND

Limited studies are available concerning on the earlier identification of AKI with sepsis. The aim of the study was to identify the risk factors of AKI early which depended on the timing onset and progression of AKI and investigate the effects of timing onset and progression of AKI on clinical outcomes.

METHODS

Patients who developed sepsis during their first 48-h admission to ICU were included. The primary outcome was major adverse kidney events (MAKE) consisted of all-cause mortality, RRT-dependence, or an inability to recover to 1.5 times of the baseline creatinine value up to 30 days. We determined MAKE and in-hospital mortality by multivariable logistic regression and explored the risk factors of early persistent-AKI. C statistics were used to evaluate model fit.

RESULTS

58.7% sepsis patients developed AKI. According to the timing onset and progression of AKI, Early transient-AKI, early persistent-AKI, late transient-AKI, late persistent-AKI were identified. Clinical outcomes were quite different among subgroups. Early persistent-AKI had 3.0-fold (OR 3.04, 95% CI 1.61 - 4.62) risk of MAKE and 2.6-fold (OR 2.60, 95%CI 1.72 - 3.76) risk of in-hospital mortality increased compared with the late transients-AKI. Older age, underweight, obese, faster heart rate, lower MAP, platelet, hematocrit, pH and energy intake during the first 24 h on ICU admission could well predict the early persistent-AKI in patients with sepsis.

CONCLUSION

Four AKI subphenotypes were identified based on the timing onset and progression of AKI. Early persistent-AKI showed higher risk of major adverse kidney events and in-hospital mortality.

TRIAL REGISTRATION

This study was registered in the Chinese Clinical Trials Registry (www.chictr.org/cn) under registration number ChiCTR-ECH-13003934.

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

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

Current management of fluid balance in critically ill patients with acute kidney injury: A scoping review

Objective

The overall objective of this scoping review is to assess the extent of the literature related to the fluid management of critically ill patients with acute kidney injury (AKI).

Introduction

AKI is common in critically ill patients where fluid therapy is a mainstay of treatment. An association between fluid balance (FB) and adverse patient-centred outcomes in critically ill patients with AKI regardless of severity has been demonstrated. The evidence for the prospective intervention of FB and its impact on outcomes is unknown.

Inclusion criteria

All studies investigating FB in patients with AKI admitted to an intensive care unit were included. Literature not related to FB in the critically ill patient with AKI population was excluded.

Methods

We searched MEDLINE, EMBASE, and CINAHL from January 1st, 2012, onwards. We included primary research studies, experimental and observational, recruiting adult participants admitted to an intensive care unit who had an AKI. We extracted data on study and patient characteristics, as well as FB, renal-based outcomes, and patient-centred outcomes. Two reviewers independently screened citations for eligible studies and performed data extraction.

Results

Of the 13,767 studies reviewed, 22 met the inclusion criteria. Two studies examined manipulation of fluid input, 18 studies assessed enhancing fluid removal, and two studies applied a restrictive fluid protocol. Sixteen studies examined patients receiving renal replacement therapy, five studies included non-renal replacement therapy patients, and one study included both. Current evidence is broad with varied approaches to managing fluid input and fluid removal. The studies did not demonstrate a consensus approach for any aspect of the fluid management of critically ill patients. There was a limited application of a restrictive fluid protocol with no conclusions possible.

Conclusions

The current body of evidence for the management of FB in critically ill patients with AKI is limited in nature. The current quality of evidence is unable to guide current clinical practice. The key outcome of this review is to highlight areas for future research.

EARLY INITIATION OF RENAL REPLACEMENT THERAPY IN INTENSIVE CARE UNIT PATIENTS WITH BOTH ACUTE RESPIRATORY DISTRESS SYNDROME AND SEPSIS WITH OR WITHOUT RENAL FAILURE: A RETROSPECTIVE COHORT STUDY BASED ON PROPENSITY SCORE MATCHING

ABSTRACT

Background: It is unknown whether early renal replacement therapy (RRT) initiation strategy in intensive care unit (ICU) patients with both acute respiratory distress syndrome (ARDS) and sepsis with or without renal failure is clinically beneficial. Patients and methods: A total of 818 patients with both ARDS and sepsis admitted to the ICU of Tianjin Medical University General Hospital were included in the analysis. Early RRT was defined as initiating the RRT strategy within 24 h of admission. The relationship between early RRT and clinical outcomes, including primary (30-day mortality) and secondary (90-day mortality, serum creatinine, Pa o2 /Fi o2 , duration of invasive mechanical ventilation, cumulative fluid output, and cumulative fluid balance) outcomes, was compared using propensity score matching (PSM). Results: A total of 277 patients (33.9% of the total population) underwent an early RRT initiation strategy before PSM. After PSM, a cohort of 147 patients with early RRT and 147 patients without early RRT with matched baseline characteristics (including serum creatinine at admission) were constructed. Early RRT was not significantly associated with 30- (hazard ratio [HR], 1.25; 95% confidence interval [CI], 0.85-1.85; P = 0.258) or 90-day mortality (HR, 1.30; 95% CI, 0.91-1.87, P = 0.150). At each time point within 72 h after admission, there was no significant difference in serum creatinine, Pa o2 /Fi o2 and duration of mechanical ventilation between the early and the no early RRT groups. Early RRT significantly increased total output at all time points within 72 h of admission and reached a statistically significant negative fluid balance at 48 h. Conclusions: Early RRT initiation strategies had no statistically significant survival benefit in ICU patients with both ARDS and sepsis, with or without renal failure, nor did they significantly improve serum creatinine and oxygenation or shorten the duration of mechanical ventilation. The use and timing of RRT in such patients should be thoroughly investigated.

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.

Organ Crosstalk in Acute Kidney Injury: Evidence and Mechanisms

Acute kidney injury (AKI) is becoming a public health problem worldwide. AKI is usually considered a complication of lung, heart, liver, gut, and brain disease, but recent findings have supported that injured kidney can also cause dysfunction of other organs, suggesting organ crosstalk existence in AKI. However, the organ crosstalk in AKI and the underlying mechanisms have not been broadly reviewed or fully investigated. In this review, we summarize recent clinical and laboratory findings of organ crosstalk in AKI and highlight the related molecular mechanisms. Moreover, their crosstalk involves inflammatory and immune responses, hemodynamic change, fluid homeostasis, hormone secretion, nerve reflex regulation, uremic toxin, and oxidative stress. Our review provides important clues for the intervention for AKI and investigates important therapeutic potential from a new perspective.

Sepsis-induced AKI: From pathogenesis to therapeutic approaches

Sepsis is a heterogenous and highly complex clinical syndrome, which is caused by infectious or noninfectious factors. Acute kidney injury (AKI) is one of the most common and severe complication of sepsis, and it is associated with high mortality and poor outcomes. Recent evidence has identified that autophagy participates in the pathophysiology of sepsis-associated AKI. Despite the use of antibiotics, the mortality rate is still at an extremely high level in patients with sepsis. Besides traditional treatments, many natural products, including phytochemicals and their derivatives, are proved to exert protective effects through multiple mechanisms, such as regulation of autophagy, inhibition of inflammation, fibrosis, and apoptosis, etc. Accumulating evidence has also shown that many pharmacological inhibitors might have potential therapeutic effects in sepsis-induced AKI. Hence, understanding the pathophysiology of sepsis-induced AKI may help to develop novel therapeutics to attenuate the complications of sepsis and lower the mortality rate. This review updates the recent progress of underlying pathophysiological mechanisms of sepsis-associated AKI, focuses specifically on autophagy, and summarizes the potential therapeutic effects of phytochemicals and pharmacological inhibitors.

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

BACKGROUND OF THE STUDY

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Timely renal replacement therapy linked to better outcome in patients with sepsis-associated acute kidney injury

Background

Recent studies suggest that acute kidney injury (AKI) can be treated with renal replacement therapy (RRT). However, its benefits to patients with sepsis-associated AKI (SA-AKI), which is linked to high mortality and morbidity rates, remain under debate. The aim of this study was to compare the outcomes of different RRT strategies for patients with SA-AKI.

Methods

This retrospective study evaluated patients who were admitted to the hospital with sepsis and developed SA-AKI during hospitalization from 1st January 2014 to 31st January 2019. Mortality, renal recovery, and systemic organ function at 90 days following admission were compared between the RRT group (RG) and non-RRT group (NRG), as well as the early-RRT group (EG) and delayed-RRT group (DG). The groups were defined according to the time from admission to RRT initiation (criterion 1, EG1 and DG1) and Kidney Disease Improving Global Outcomes (KDIGO) classification (criterion 2, EG2 and DG2). Categorical and continuous variables were compared using the chi-squared test or Fisher's exact test and Student's t-test or Wilcoxon test. Kaplan-Meier curves were constructed to determine the unadjusted survival rates for the different subgroups.

Results

A total of 116 patients were included in this study; of those, 38 received RRT and 46 expired within 90 days. Among different strategies of RRT, there were no significant differences found in 90-day mortality (RG vs. NRG: χ²=0.610, P=0.435; EG1 vs. DG1: χ² =0.835, P=0.360; EG2 vs. DG2: χ²=0.022, P=0.899) and renal recovery. However, the values of change in sequential organ failure assessment (ΔSOFA)_max-min of patients in the EG and RG were significantly higher than those recorded in the NRG (ΔSOFA_RG=7.0, ΔSOFA_NRG=3.60, ΔSOFA_EG1=9.00, ΔSOFA_EG2=6.30; P<0.050). Also, the 90-day renal recovery in the EG was better than that noted in the DG with criterion 1 (87.5% vs. 38.5%, respectively, χ²=10.425, P=0.032), suggesting that RRT (especially timely RRT) may be beneficial to the restoration of systemic organ function in patients with SA-AKI.

Conclusion

RRT did not reduce the 90-day mortality among patients with SA-AKI. However, timely RRT may benefit the restoration of systemic organ function, thereby improving the quality of life of patients.

Permissive azotemia during acute kidney injury enables more rapid renal recovery and less renal fibrosis: a hypothesis and clinical development plan

Preclinical models of acute kidney injury (AKI) consistently demonstrate that a uremic milieu enhances renal recovery and decreases kidney fibrosis. Similarly, significant decreases in monocyte/macrophage infiltration, complement levels, and other markers of inflammation in the injured kidney are observed across multiple studies and species. In essence, decreased renal clearance has the surprising and counterintuitive effect of being an effective treatment for AKI. In this Perspective, the author suggests a hypothesis describing why the uremic milieu is kidney protective and proposes a clinical trial of ‘permissive azotemia’ to improve renal recovery and long-term renal outcomes in critically ill patients with severe AKI.

Personalization of renal replacement therapy initiation: a secondary analysis of the AKIKI and IDEAL-ICU trials

Background

Trials comparing early and delayed strategies of renal replacement therapy in patients with severe acute kidney injury may have missed differences in survival as a result of mixing together patients at heterogeneous levels of risks. Our aim was to evaluate the heterogeneity of treatment effect on 60-day mortality from an early vs a delayed strategy across levels of risk for renal replacement therapy initiation under a delayed strategy.

Methods

We used data from the AKIKI, and IDEAL-ICU randomized controlled trials to develop a multivariable logistic regression model for renal replacement therapy initiation within 48 h after allocation to a delayed strategy. We then used an interaction with spline terms in a Cox model to estimate treatment effects across the predicted risks of RRT initiation.

Results

We analyzed data from 1107 patients (619 and 488 in the AKIKI and IDEAL-ICU trial respectively). In the pooled sample, we found evidence for heterogeneous treatment effects (P = 0.023). Patients at an intermediate-high risk of renal replacement therapy initiation within 48 h may have benefited from an early strategy (absolute risk difference, − 14%; 95% confidence interval, − 27% to − 1%). For other patients, we found no evidence of benefit from an early strategy of renal replacement therapy initiation but a trend for harm (absolute risk difference, 8%; 95% confidence interval, − 5% to 21% in patients at intermediate-low risk).

Conclusions

We have identified a clinically sound heterogeneity of treatment effect of an early vs a delayed strategy of renal replacement therapy initiation that may reflect varying degrees of kidney demand-capacity mismatch.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13054-022-03936-y.

[Acute kidney injury in intensive care unit: A review]

Acute kidney injury is a common complication in intensive care unit. Its incidence is variable according to the studies. It is considered to occur in more than 50 % of patients. Acute kidney injury is responsible for an increase in morbidity (length of hospitalization, renal replacement therapy) but also for excess mortality. The commonly accepted definition of acute kidney injury comes from the collaborative workgroup named Kidney Disease: Improving Global Outcomes (KDIGO). It made it possible to standardize practices and raise awareness among practitioners about monitoring plasma creatinine and also diuresis. Acute kidney injury in intensive care unit is a systemic disease including circulatory, endothelial, epithelial and cellular function involvement and an acute kidney injury is not accompanied by ad integrum repair. After prolonged injury, inadequate repair begins with a fibrotic process. Several mechanisms are involved (cell cycle arrest, epithelial-mesenchymal transition, mitochondrial dysfunction) and result in improper repair. A continuum exists between acute kidney disease and chronic kidney disease, characterized by different renal recovery phenotypes. Thus, preventive measures to prevent the occurrence of kidney damage play a major role in management. The nephrologist must be involved at every stage, from the prevention of the first acute kidney injury (upon arrival in intensive care unit) to long-term follow-up and the care of a chronic kidney disease.

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

PURPOSE OF REVIEW

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

RECENT FINDINGS

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

SUMMARY

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

Sentiment Analysis for Necessary Preview of 30-Day Mortality in Sepsis Patients and the Control Strategies

This study was to preview the risk of 30-day mortality in sepsis patients using sentiment analysis. The clinical data of patients and nursing notes were collected from the Medical Information Mart for Intensive Care (MIMIC-III) database. The factors influencing 30-day mortality were analyzed using the Cox regression model. And, the prognostic index (PI) was estimated. The receiver operating characteristic (ROC) curve was used to determine the PI cut-off point and assess the prediction ability of the model. In total, 1844 of 3560 patients were eligible for the study, with a 30-day mortality of 37.58%. Multivariate Cox analysis showed that sentiment polarity scores, sentiment subjectivity scores, simplified acute physiology score (SAPS)-II, age, and intensive care unit (ICU) types were all associated with the risk of 30-day mortality (P < 0.05). In the preview of 30-day mortality, the area under the curve (AUC) of ROC was 0.78 (95%CI: 0.74–0.81,P < 0.001) when the cut-off point of PI was 0.467. The documented notes from nurses were described for the first time. Sentiment scores measured in nursing notes are associated with the risk of 30-day mortality in sepsis patients and may improve the preview of 30-day mortality.

The Effect of Long-Term Duration Renal Replacement Therapy on Outcomes of Critically Ill Patients with Acute Kidney Injury: A Retrospective Cohort Study

Background

Renal replacement therapy (RRT), as a cornerstone of supportive treatment, has long been performed in critically ill patients with acute kidney injury (AKI). However, the majority of studies may have neglected the effect of the duration of RRT  on the outcome of AKI patients. This paper is aiming to explore the effect of the long duration of RRT  on the outcome of critically ill patients with AKI.

Methods

This retrospective study was conducted by using the Multiparameter Intelligent Monitoring in Intensive Care II (MIMIC-II) database. The primary outcome measure of this study was the mortality at 28 days, 60 days, and 90 days in the long-duration RRT group and the non-long-duration RRT group. The secondary outcomes assessed the difference in clinical outcome in these two groups. Lastly, the effect of the duration of RRT on mortality in AKI patients was determined as the third outcome.

Results

We selected 1,020 patients in total who received RRT according to the MIMIC-II database. According to the inclusion and exclusion criteria, we finally selected 506 patients with AKI: 286 AKI patients in the non-long-duration RRT group and 220 in the long-duration RRT group. After 28 days, there was a significant difference in all-cause mortality between the long-duration RRT group and the non-long-duration RRT group (P=0.001). However, the difference disappeared after 60 days and 90 days (P=0.803 and P=0.925, respectively). The length of ICU stay, length of hospital stay, and duration of mechanical ventilation were significantly longer in the long-duration RRT group than those in the non-long-duration RRT group. Considering 28-day mortality, the longer duration of RRT was shown to be a protective factor (HR = 0.995, 95% CI 0.993-0.997, P < 0.0001), while 60-day and 90-day mortality were not correlated with improved protection.

Conclusions

The long duration of RRT can improve the short-term prognosis of AKI patients, but it does not affect the long-term prognosis of these patients. Prognosis is determined by the severity of the illness itself. This suggests that RRT can protect AKI patients through the most critical time; however, the final outcome cannot be altered.

Acute kidney injury in ECMO patients

This article is one of ten reviews selected from the Annual Update in Intensive Care and Emergency Medicine 2021. Other selected articles can be found online at  https://www.biomedcentral.com/collections/annualupdate2021 . Further information about the Annual Update in Intensive Care and Emergency Medicine is available from  https://link.springer.com/bookseries/8901 .

Acute kidney injury

Acute kidney injury (AKI) is defined by a sudden loss of excretory kidney function. AKI is part of a range of conditions summarized as acute kidney diseases and disorders (AKD), in which slow deterioration of kidney function or persistent kidney dysfunction is associated with an irreversible loss of kidney cells and nephrons, which can lead to chronic kidney disease (CKD). New biomarkers to identify injury before function loss await clinical implementation. AKI and AKD are a global concern. In low-income and middle-income countries, infections and hypovolaemic shock are the predominant causes of AKI. In high-income countries, AKI mostly occurs in elderly patients who are in hospital, and is related to sepsis, drugs or invasive procedures. Infection and trauma-related AKI and AKD are frequent in all regions. The large spectrum of AKI implies diverse pathophysiological mechanisms. AKI management in critical care settings is challenging, including appropriate volume control, nephrotoxic drug management, and the timing and type of kidney support. Fluid and electrolyte management are essential. As AKI can be lethal, kidney replacement therapy is frequently required. AKI has a poor prognosis in critically ill patients. Long-term consequences of AKI and AKD include CKD and cardiovascular morbidity. Thus, prevention and early detection of AKI are essential.

Early Goal-Directed Renal Replacement Therapy in Acute Decompensated Heart Failure Patients with Cardiorenal Syndrome

INTRODUCTION

The aim of this study was to clarify the efficacy of early goal-directed renal replacement therapy (GDRRT) for treatment of cardiorenal syndrome (CRS) patients after acute decompensated heart failure (ADHF).

METHODS

In the retrospective, observational study, we enrolled 54 patients in the early GDRRT group and 63 patients in the late GDRRT group. Baseline characteristics, clinical data at initiation renal replacement therapy time, and the clinical outcome were collected and several parameters were compared and analyzed between 2 groups.

RESULTS

The urine volume at GDRRT initiation time in the early group was higher than that in the late GDRRT group (1,060.3 ± 332.1 vs. 300.5 ± 148.3 mL, p < 0.001). Hemodynamic parameters such as mean artery pressure were higher (70.06 ± 32.99 vs. 54.34 ± 40.88 mm Hg, p = 0.012), the heart rate was slower (80.17 ± 15.26 vs. 99.21 ± 25.45 bpm, p = 0.002), and the diameter of inferior vena cava was narrower (22.00 ± 1.91 vs. 25.77 ± 5.5 mm, p = 0.04) in early GDRRT. Primary end point was inhospital all-cause mortality and cardiovascular mortality, which was obviously lower in the early GDRRT group (respectively 24.1 vs. 60.3%, p = 0.002 and 20.3 vs. 50.8%, p = 0.005). The second end point of kidney recovery in the early GDRRT group was much better than that in the latter GDRRT group (p = 0.018). Moreover, urine volume after GDRRT of the early group was more significant than that of the late group (1,432 ± 172 vs. 702 ± 183 mL, p = 0.005).

CONCLUSION

This study clarified the effectiveness of the early GDRRT strategy in ADHF patients suffered from CRS, which reduced inhospital mortality and improved the urine output and clinical kidney recovery outcome.

Improving the quality of care for patients requiring continuous renal replacement therapy

Continuous renal replacement therapy (CRRT) is the preferred extracorporeal kidney support therapy employed to support critically ill patients with acute or chronic kidney dysfunction in intensive care units. Significant heterogeneity in CRRT practice exists in part due to variable logistics, resources, and scarcity of evidence-based CRRT practices. Importantly, homogenization of practice patterns by developing substantial evidence and effective dissemination among providers is essential for optimizing CRRT practices. The emphasis on quality of CRRT delivery has prompted identification of potential quality indicators, development of multifaceted quality improvement initiatives, effective computer science utilization, and a surge of multidisciplinary quality assurance teams that advocate for "best" CRRT practices. This manuscript provides an overview of quality improvement methodologies and reviews candidate quality indicators of CRRT and the impact of quality improvement on enhancing CRRT delivery practices.

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.

Precision renal replacement therapy

PURPOSE OF REVIEW

This article reviews the current evidence supporting the use of precision medicine in the delivery of acute renal replacement therapy (RRT) to critically ill patients, focusing on timing, solute control, anticoagulation and technologic innovation.

RECENT FINDINGS

Precision medicine is most applicable to the timing of RRT in critically ill patients. As recent randomized controlled trials have failed to provide consensus on when to initiate acute RRT, the decision to start acute RRT should be based on individual patient clinical characteristics (e.g. severity of the disease, evolution of clinical parameters) and logistic considerations (e.g. organizational issues, availability of machines and disposables). The delivery of a dynamic dialytic dose is another application of precision medicine, as patients may require different and varying dialysis doses depending on individual patient factors and clinical course. Although regional citrate anticoagulation (RCA) is recommended as first-line anticoagulation for continuous RRT, modifications to RCA protocols and consideration of other anticoagulants should be individualized to the patient's clinical condition. Finally, the evolution of RRT technology has improved precision in dialysis delivery through increased machine accuracy, connectivity to the electronic medical record and automated reduction of downtime.

SUMMARY

RRT has become a complex treatment for critically ill patients, which allows for the prescription to be precisely tailored to the different clinical requirements.

[COVID-19 and acute kidney injury in the intensive care unit]

Acute kidney injury (AKI) is a frequent and severe complication in coronavirus disease 2019 (COVID-19) patients in the intensive care unit. The development of COVID-19 associated AKI is closely linked to the severity of the disease course. The main risk factor for kidney failure requiring kidney replacement therapy is the necessity for invasive ventilation, whereby the onset of renal failure is often closely associated with the timing of intubation. Additionally, the risk factors for a severe course of COVID-19 have been shown to also be risk factors for renal failure. AKI in COVID-19 shows a high mortality and in some patients leads to chronic kidney disease; however, full recovery of kidney function in survivors who need dialysis is not uncommon. With respect to prevention and treatment of renal failure associated with COVID-19, the same recommendations as for AKI from other causes are valid (Kidney Disease: Improving Global Outcomes, KDIGO bundles). Due to the large numbers of patients in the setting of overwhelmed resources, the availability of extracorporeal renal replacement procedures can become critical, especially since hypercoagulation is frequent in COVID‑19. In order to avoid triage situations, in some centers acute peritoneal dialysis was used as an alternative to extracorporeal procedures.

[Acute kidney injury following acute pancreatitis (AP-AKI): Definition, Pathophysiology, Diagnosis and Therapy]

Acute pancreatitis (AP) is the most frequent gastrointestinal cause for hospitalization and one of the leading causes of in-hospital deaths. Severe acute pancreatitis is often associated with multiorgan failure and especially with acute kidney injury (AKI). AKI can develop early or late in the course of the disease and is a strong determinator of outcome. The mortality in the case of dialysis-dependent AKI and acute pancreatitis raises exponentially in the affected patients. AP-induced AKI (AP-AKI) shows many similarities but also distinct differences to other causes of AKI occurring in the intensive care unit setting. The knowledge of the exact pathophysiology can help to adjust, control and improve therapeutic approaches to the disease. Unfortunately, there are only a few studies dealing with AP and AKI.In this review, we discuss recent data about pathogenesis, causes and management of AP-AKI in patients with severe acute pancreatitis and exploit in this regard the diagnostic and prognostic potential of respective newer serum and urine markers.

Continuous Venovenous Hemofiltration is Associated with Improved Survival in Burn Patients with Shock: A Subset Analysis of a Multicenter Observational Study

INTRODUCTION

Acute kidney injury (AKI) is associated with high mortality in burn patients. Previously, we reported that timely initiation of renal replacement therapy (RRT) with an individualized preference toward continuous modes at relatively higher than recommended doses has become standard practice in critically ill burn patients with AKI and is associated with a historically low mortality. The purpose of this cohort analysis was to determine if modality choice impacted survival in burn patients.

METHODS

After Institutional Review Board approval, a subset analysis was performed on de-identified data collected during a multicenter, observational study. All patients (n = 170) were 18 years or older, admitted with severe burn injuries and started on RRT. Comparisons were made utilizing χ2 or Fisher's exact test. Kaplan-Meier plots were utilized to assess survival. Sample size determinations to aid future research were calculated utilizing χ2 test with a Yates Correction Factor.

RESULTS

Demographics and revised Baux were similar between groups. When continuous venovenous hemofiltration (CVVH) was compared to all other modalities, there was no statistically significant difference in survival (56 vs. 43%, p = 0.124). However, survival was significantly improved (54 vs. 37%, p = 0.032) in the subset of patients requiring vasopressors (n = 77). There was no statistically significant survival difference in patients with inhalation injury (38 vs. 29%, p = 0.638) or acute lung injury/acute respiratory distress syndrome (51 vs. 33%, p = 0.11).

DISCUSSION/CONCLUSION

Survival may be improved if CVVH is chosen as the preferred modality in burn patients with shock and requiring RRT. Differences in other subsets were promising, but analysis was underpowered. Further research should determine if modality choice provides survival benefit in any other subset of burn injury.

Kidney injury in COVID-19

Coronavirus disease 2019 (COVID-19) continues to affect millions of people around the globe. As data emerge, it is becoming more evident that extrapulmonary organ involvement, particularly the kidneys, highly influence mortality. The incidence of acute kidney injury has been estimated to be 30% in COVID-19 non-survivors. Current evidence suggests four broad mechanisms of renal injury: Hypovolaemia, acute respiratory distress syndrome related, cytokine storm and direct viral invasion as seen on renal autopsy findings. We look to critically assess the epidemiology, pathophysiology and management of kidney injury in COVID-19.

Mortality and host response aberrations associated with transient and persistent acute kidney injury in critically ill patients with sepsis: a prospective cohort study

Purpose

Sepsis is the most frequent cause of acute kidney injury (AKI). The “Acute Disease Quality Initiative Workgroup” recently proposed new definitions for AKI, classifying it as transient or persistent. We investigated the incidence, mortality, and host response aberrations associated with transient and persistent AKI in sepsis patients.

Methods

A total of 1545 patients admitted with sepsis to 2 intensive care units in the Netherlands were stratified according to the presence (defined by any urine or creatinine RIFLE criterion within the first 48 h) and evolution of AKI (with persistent defined as remaining > 48 h). We determined 30-day mortality by logistic regression adjusting for confounding variables and analyzed 16 plasma biomarkers reflecting pathways involved in sepsis pathogenesis (n = 866) and blood leukocyte transcriptomes (n = 392).

Results

AKI occurred in 37.7% of patients, of which 18.4% was transient and 81.6% persistent. On admission, patients with persistent AKI had higher disease severity scores and more frequently had severe (injury or failure) RIFLE AKI stages than transient AKI patients. Persistent AKI, but not transient AKI, was associated with increased mortality by day 30 and up to 1 year. Persistent AKI was associated with enhanced and sustained inflammatory and procoagulant responses during the first 4 days, and a more severe loss of vascular integrity compared with transient AKI. Baseline blood gene expression showed minimal differences with respect to the presence or evolution of AKI.

Conclusion

Persistent AKI is independently associated with sepsis mortality, as well as with sustained inflammatory and procoagulant responses, and loss of vascular integrity as compared with transient AKI.

Electronic supplementary material

The online version of this article (10.1007/s00134-020-06119-x) contains supplementary material, which is available to authorized users.

Impact of Early Acute Kidney Injury on Management and Outcome in Patients with Acute Respiratory Distress Syndrome: A Secondary Analysis of a Multicenter Observational Study. Crit Care Med. 2019;47:1216-1225. [PMID: 31162201 DOI: 10.1097/ccm.0000000000003832]

OBJECTIVES

To understand the impact of mild-moderate and severe acute kidney injury in patients with acute respiratory distress syndrome.

DESIGN

Secondary analysis of the "Large Observational Study to Understand the Global Impact of Severe Acute Respiratory Failure", an international prospective cohort study of patients with severe respiratory failure.

SETTING

Four-hundred fifty-nine ICUs from 50 countries across five continents.

SUBJECTS

Patients with a glomerular filtration rate greater than 60 mL/min/1.73 m prior to admission who fulfilled criteria of acute respiratory distress syndrome on day 1 and day 2 of acute hypoxemic respiratory failure.

INTERVENTIONS

Patients were categorized based on worst serum creatinine or urine output into: 1) no acute kidney injury (serum creatinine < 132 µmol/L or urine output ≥ 0.5 mL/kg/hr), 2) mild-moderate acute kidney injury (serum creatinine 132-354 µmol/L or minimum urine output between 0.3 and 0.5mL/kg/hr), or 3) severe acute kidney injury (serum creatinine > 354 µmol/L or renal replacement therapy or minimum urine output < 0.3 mL/kg/hr).

MEASUREMENTS AND MAIN RESULTS

The primary outcome was hospital mortality, whereas secondary outcomes included prevalence of acute kidney injury and characterization of acute respiratory distress syndrome risk factors and illness severity patterns, in patients with acute kidney injury versus no acute kidney injury. One-thousand nine-hundred seventy-four patients met inclusion criteria: 1,209 (61%) with no acute kidney injury, 468 (24%) with mild-moderate acute kidney injury, and 297 (15%) with severe acute kidney injury. The impact of acute kidney injury on the ventilatory management of patients with acute respiratory distress syndrome was relatively limited, with no differences in arterial CO2 tension or in tidal or minute ventilation between the groups. Hospital mortality increased from 31% in acute respiratory distress syndrome patients with no acute kidney injury to 50% in mild-moderate acute kidney injury (p ≤ 0.001 vs no acute kidney injury) and 58% in severe acute kidney injury (p ≤ 0.001 vs no acute kidney injury and mild-moderate acute kidney injury). In multivariate analyses, both mild-moderate (odds ratio, 1.61; 95% CI, 1.24-2.09; p < 0.001) and severe (odds ratio, 2.13; 95% CI, 1.55-2.94; p < 0.001) acute kidney injury were independently associated with mortality.

CONCLUSIONS

The development of acute kidney injury, even when mild-moderate in severity, is associated with a substantial increase in mortality in patients with acute respiratory distress syndrome.

Typology of Published Randomized Controlled Trials Investigating Initial Ventilation Strategy in Critically Ill Patients With Acute Respiratory Failure: A Methodologic Review

BACKGROUND

Randomized controlled trials (RCTs) in patients with hypoxemic acute respiratory failure (ARF) often failed to show survival benefits and resulted in varying clinical end points.

RESEARCH QUESTION

This methodologic review was conducted of published RCTs on ARF, with a careful attention to whether the study results were positive or negative.

STUDY DESIGN AND METHODS

MEDLINE, Cochrane Central Register of Controlled Trials, and Web of Science were searched for published RCTs in adult patients with ARF between January 1995 and December 2019. The objective was to investigate sources of heterogeneity and factors associated with a positive RCT (ie, with a significant difference on the primary end point). To determine the importance of the primary end point choice, end points were classified as follows: (1) respiratory event end points (corresponding to modification of the ventilation support); (2) physiologic/clinical end points (corresponding to oxygenation or clinical parameters); and (3) mortality. The Cochrane risk-of-bias tool was used to assess study quality.

RESULTS

Seventy-four RCTs were included (57% were single-center RCTs) comparing mainly oxygenation/ventilation strategies (95%) in patients with various ARF causes (62%); studies were stopped prematurely in 20% of the trials. A standardized management of ARF was observed in 24 (32%) trials. Twenty-two distinct primary end points have been used, the first of which were those based on respiratory events (44 RCTs [49%]), namely intubation in 76% of the cases. Physiologic/clinical end points have been used in 21 trials (29%) and mortality in nine (12%). Overall, 42 (57%) RCTs were positive, 52% in studies with respiratory event end points, 76% in studies with physiologic/clinical end points, and 33% in studies with mortality end points. Adjusted for study quality (Cochrane risk-of-bias tool), factors associated with a positive RCT included clinically based primary end points (OR, 8.40; 95% CI, 1.35-65.79), the use of standardized ARF management (OR, 4.55; 95% CI, 1.02-22.88), and single-center trials (OR, 3.85; 95% CI, 1.25-13.11).

INTERPRETATION

The typology of published RCTs in patients with ARF could be used to frame future trial designs in this field and guide clinicians and researchers toward optimal research transfer to the bedside.

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.

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.

The Artificial Kidney Initiation in Kidney Injury 2 (AKIKI2): study protocol for a randomized controlled trial

BACKGROUND

The Artificial Kidney Initiation in Kidney Injury (AKIKI) trial showed that a delayed renal replacement therapy (RRT) strategy for severe acute kidney injury (AKI) in critically ill patients was safe and associated with major reduction in RRT initiation compared with an early strategy. The five criteria which mandated RRT initiation in the delayed arm were: severe hyperkalemia, severe acidosis, acute pulmonary edema due to fluid overload resulting in severe hypoxemia, serum urea concentration > 40 mmol/l and oliguria/anuria > 72 h. However, duration of anuria/oliguria and level of blood urea are still criteria open to debate. The objective of the study is to compare the delayed strategy used in AKIKI (now termed "standard") with another in which RRT is further delayed for a longer period (termed "delayed strategy").

METHODS/DESIGN

This is a prospective, multicenter, open-label, two-arm randomized trial. The study is composed of two stages (observational and randomization stages). At any time, the occurrence of a potentially severe condition (severe hyperkalemia, severe metabolic or mixed acidosis, acute pulmonary edema due to fluid overload resulting in severe hypoxemia) suggests immediate RRT initiation. Patients receiving (or who have received) intravenously administered catecholamines and/or invasive mechanical ventilation and presenting with AKI stage 3 of the KDIGO classification and with no potentially severe condition are included in the observational stage. Patients presenting a serum urea concentration > 40 mmol/l and/or an oliguria/anuria for more than 72 h are randomly allocated to a standard (RRT is initiated within 12 h) or a delayed RRT strategy (RRT is initiated only if an above-mentioned potentially severe condition occurs or if the serum urea concentration reaches 50 mmol/l). The primary outcome will be the number of RRT-free days at day 28. One interim analysis is planned. It is expected to include 810 patients in the observational stage and to randomize 270 subjects.

DISCUSSION

The AKIKI2 study should improve the knowledge of RRT initiation criteria in critically ill patients. The potential reduction in RRT use allowed by a delayed RRT strategy might be associated with less invasive care and decreased costs. Enrollment is ongoing. Inclusions are expected to be completed by November 2019.

TRIAL REGISTRATION

ClinicalTrials.gov, ID: NCT03396757. Registered on 11 January 2018.

Lung-kidney interactions in critically ill patients: consensus report of the Acute Disease Quality Initiative (ADQI) 21 Workgroup

BACKGROUND

Multi-organ dysfunction in critical illness is common and frequently involves the lungs and kidneys, often requiring organ support such as invasive mechanical ventilation (IMV), renal replacement therapy (RRT) and/or extracorporeal membrane oxygenation (ECMO).

METHODS

A consensus conference on the spectrum of lung-kidney interactions in critical illness was held under the auspices of the Acute Disease Quality Initiative (ADQI) in Innsbruck, Austria, in June 2018. Through review and critical appraisal of the available evidence, the current state of research, and both clinical and research recommendations were described on the following topics: epidemiology, pathophysiology and strategies to mitigate pulmonary dysfunction among patients with acute kidney injury and/or kidney dysfunction among patients with acute respiratory failure/acute respiratory distress syndrome. Furthermore, emphasis was put on patients receiving organ support (RRT, IMV and/or ECMO) and its impact on lung and kidney function.

CONCLUSION

The ADQI 21 conference found significant knowledge gaps about organ crosstalk between lung and kidney and its relevance for critically ill patients. Lung protective ventilation, conservative fluid management and early recognition and treatment of pulmonary infections were the only clinical recommendations with higher quality of evidence. Recommendations for research were formulated, targeting lung-kidney interactions to improve care processes and outcomes in critical illness.

Improved survival rates in patients with H1N1 acute respiratory failure in Korea between 2009 and 2016

There was a pandemic of influenza A (H1N1) in 2009; in Korea, there was also an H1N1 epidemic in 2016. We aim to investigate whether survival had improved in the setting of recent advances in intensive care unit (ICU) management. We conducted a retrospective analysis of acute respiratory failure patients with H1N1 influenza pneumonia in 2016 and 2009 respectively at two tertiary referral hospitals in Korea. A total of 28 patients were treated in 2016, and 34 in 2009. There was no significant difference in SOFA scores on ICU admission day. In-hospital mortality was significantly lower in patients of 2016 compared to those of 2009 (18% vs. 44% P = 0.028). By multivariable analyses, the treatment year 2016 was associated with a greater likelihood of survival. Compared to the patients treated in 2009, those treated in 2016 were one seventh as likely to die after adjusting for other clinical variables (hazard ratio for mortality, 0.15; 95% confidence interval. 0.03–0.63, P = 0.010). Improved survival in patients who underwent extracorporeal membrane oxygenation treatment (in-hospital mortality, 17% vs. 60%, P = 0.242) and decreased tidal volumes during mechanical ventilation (median 5.4 mL/kg vs. median 9.2 mL/kg, P = 0.018) were observed in 2016 compared to 2009. Treatment outcomes for patients with H1N1 acute respiratory failure improved from 2009 to 2016 in two tertiary referral centers in South Korea.

Continuous renal replacement therapy: individualization of the prescription

PURPOSE OF REVIEW

Continuous renal replacement therapy (CRRT) is now the mainstay of renal organ support in the critically ill. As our understanding of CRRT delivery and its impact on patient outcomes improves there is a focus on researching the potential benefits of tailored, patient-specific treatments to meet dynamic needs.

RECENT FINDINGS

The most up-to-date studies investigating aspects of CRRT prescription that can be individualized: CRRT dose, timing, fluid management, membrane selection, anticoagulation and vascular access are reviewed. The use of different doses of CRRT lack conventional high-quality evidence and importantly studies reveal variation in assessment of dose delivery. Research reveals conflicting evidence for clinicians in distinguishing which patients will benefit from 'watchful waiting' vs. early initiation of CRRT. Both dynamic CRRT dosing and precision fluid management using CRRT are difficult to investigate and currently only observational data supports individualization of prescriptions. Similarly, individualization of membrane choice is largely experimental.

SUMMARY

Clinicians have limited evidence to individualize the prescription of CRRT. To develop this, we need to understand the requirements for renal support for individual patients, such as electrolyte imbalance, fluid overload or clearance of systemic inflammatory mediators to allow us to target these abnormalities in appropriately designed randomized trials.

Renal Replacement Therapy in the Critical Care Setting. Crit Care Res Pract. 2019;2019:6948710. [PMID: 31396416 PMCID: PMC6664494 DOI: 10.1155/2019/6948710]

Renal replacement therapy (RRT) is frequently required to manage critically ill patients with acute kidney injury (AKI). There is limited evidence to support the current practice of RRT in intensive care units (ICUs). Recently published randomized control trials (RCTs) have further questioned our understanding of RRT in critical care. The optimal timing and dosing continues to be debatable; however, current evidence suggests delayed strategy with less intensive dosing when utilising RRT. Various modes of RRT are complementary to each other with no definite benefits to mortality or renal function preservation. Choice of anticoagulation remains regional citrate anticoagulation in continuous renal replacement therapy (CRRT) with lower bleeding risk when compared with heparin. RRT can be used to support resistant cardiac failure, but evolving therapies such as haemoperfusion are currently not recommended in sepsis.

Clinical predictors of renal non-recovery in acute respiratory distress syndrome

Background

Acute kidney injury (AKI) is the most common extra-pulmonary organ failure in acute respiratory distress syndrome (ARDS). Renal recovery after AKI is determined by several factors. The objective of this study was to determine the predictors of renal non-recovery in ARDS patients.

Methods

A single center retrospective cohort study of patients with AKI after onset of ARDS. Patients with preexisting chronic kidney disease or intensive care unit stay < 24 h were excluded. AKI staging was defined according to the Kidney Disease Improving Global Outcomes (KDIGO) 2012 guidelines. Renal non-recovery was defined as death, dialysis dependence, serum creatinine ≥1.5 times the baseline, or urine output < 0.5 mL/kg/h more than 6 h.

Results

Of the 244 patients that met study criteria, 60 (24.6%) had stage I AKI, 66 (27%) had stage II AKI, and 118 (48.4%) had stage III AKI. Of those, 148 (60.7%) patients had renal non-recovery. On multivariable analysis, factors associated with renal non-recovery were a higher stage of AKI (odds ratio [OR] stage II 5.71, 95% confidence interval [CI] 2.17–14.98; OR stage III 45.85, 95% CI 16.27–129.2), delay in the onset of AKI (OR 1.12, 95% CI 1.03–1.21), history of malignancy (OR 4.02, 95% CI 1.59–10.15), septic shock (OR 3.2, 95% CI 1.52–6.76), and a higher tidal volume on day 1–3 of ARDS (OR 1.41, 95% CI 1.05–1.90). Subgroup analysis of survival at day 28 of ARDS also found that higher severity of AKI (OR stage II 8.17, 95% CI 0.84–79.91; OR stage III 111.67, 95% CI 12.69–982.91), delayed onset of AKI (OR 1.12, 95% CI 1.02–1.23), and active malignancy (OR 6.55, 95% CI 1.34–32.04) were significant predictors of renal non-recovery.

Conclusions

A higher stage of AKI, delayed onset of AKI, a history of malignancy, septic shock, and a higher tidal volume on day 1–3 of ARDS predicted renal non-recovery in ARDS patients. Among survivors, a higher stage of AKI, delayed onset of AKI, and a history of malignancy were associated with renal non-recovery.

Electronic supplementary material

The online version of this article (10.1186/s12882-019-1439-2) contains supplementary material, which is available to authorized users.

Translational gap in pediatric septic shock management: an ESPNIC perspective

Background

The Surviving Sepsis Campaign and the American College of Critical Care Medicine guidelines have provided recommendations for the management of pediatric septic shock patients. We conducted a survey among the European Society of Pediatric and Neonatal Intensive Care (ESPNIC) members to assess variations to these recommendations.

Methods

A total of 114 pediatric intensive care physicians completed an electronic survey. The survey consisted of four standardized clinical cases exploring seven clinical scenarios.

Results

Among the seven different clinical scenarios, the types of fluids were preferentially non-synthetic colloids (albumin) and crystalloids (isotonic saline) and volume expansion was not limited to 60 ml/kg. Early intubation for mechanical ventilation was used by 70% of the participants. Norepinephrine was stated to be used in 94% of the PICU physicians surveyed, although dopamine or epinephrine is recommended as first-line vasopressors in pediatric septic shock. When norepinephrine was used, the addition of another inotrope was frequent. Specific drugs such as vasopressin or enoximone were used in < 20%. Extracorporeal life support was used or considered by 91% of the physicians audited in certain specific situations, whereas the use of high-flow hemofiltration was considered for 44%.

Conclusions

This pediatric septic shock management survey outlined variability in the current clinician-reported practice of pediatric septic shock management. As most recommendations are not supported by evidence, these findings outline some limitation of existing pediatric guidelines in regard to context and patient’s specificity.

Electronic supplementary material

The online version of this article (10.1186/s13613-019-0545-4) contains supplementary material, which is available to authorized users.

Acute kidney injury from sepsis: current concepts, epidemiology, pathophysiology, prevention and treatment

Sepsis-associated acute kidney injury (S-AKI) is a frequent complication of the critically ill patient and is associated with unacceptable morbidity and mortality. Prevention of S-AKI is difficult because by the time patients seek medical attention, most have already developed acute kidney injury. Thus, early recognition is crucial to provide supportive treatment and limit further insults. Current diagnostic criteria for acute kidney injury has limited early detection; however, novel biomarkers of kidney stress and damage have been recently validated for risk prediction and early diagnosis of acute kidney injury in the setting of sepsis. Recent evidence shows that microvascular dysfunction, inflammation, and metabolic reprogramming are 3 fundamental mechanisms that may play a role in the development of S-AKI. However, more mechanistic studies are needed to better understand the convoluted pathophysiology of S-AKI and to translate these findings into potential treatment strategies and add to the promising pharmacologic approaches being developed and tested in clinical trials.

Actualités sur le sepsis et le choc septique de l’enfant

L’incidence du sepsis de l’enfant augmente en réanimation pédiatrique. La définition du sepsis et du choc septique de l’enfant est amenée à évoluer à l’instar de celle du choc septique de l’adulte pour détecter les patients nécessitant une prise en charge urgente et spécialisée. La prise en charge d’un patient septique repose sur une oxygénothérapie, une expansion volémique au sérum salé isotonique, une antibiothérapie et un transfert dans un service de réanimation ou de surveillance continue pédiatrique. Le taux et la cinétique d’élimination du lactate plasmatique est un bon critère diagnostic et pronostic qui permet de guider la prise en charge. La présence de plusieurs défaillances d’organes ou une défaillance circulatoire aiguë signe le diagnostic de sepsis encore dit sévère, et leur persistance et/ou la non-correction de l’hypotension artérielle malgré un remplissage vasculaire d’au moins 40 ml/kg définit le choc septique chez l’enfant. Dans ce cas, la correction rapide de l’hypotension artérielle persistante repose sur la noradrénaline initiée sur une voie intraveineuse périphérique dans l’attente d’un accès veineux central. L’échographie cardiaque est un examen clé de l’évaluation hémodynamique du patient, pour guider la poursuite de l’expansion volémique ou détecter une cardiomyopathie septique. Des thérapeutiques additionnelles ont été proposées pour prendre en charge certains patients avec des défaillances d’organes particulières. L’immunomonitorage et la modulation sont un ensemble de techniques qui permettent la recherche et le traitement de certaines complications. La Surviving Sepsis Campaign a permis d’améliorer la prise en charge de ces patients par l’implémentation d’algorithmes de détection et de prise en charge du sepsis de l’enfant. Une révision pédiatrique de cette campagne est attendue prochainement.