Outcomes of sustained low efficiency dialysis versus continuous renal replacement therapy in critically ill adults with acute kidney injury: a cohort study

Experience of Sustained Low-Efficiency Dialysis (SLED) in an Intensive Care Unit of a Quaternary Care Hospital

BACKGROUND

In critically ill patients, sustained low-efficiency dialysis (SLED) has become a viable option for treating acute kidney injury (AKI) instead of continuous renal replacement therapy (CRRT). This study aimed to evaluate clinical outcomes in critically ill patients receiving SLED.

MATERIAL AND METHODS

In our ICU, we performed a retrospective cohort study on hemodynamically unstable patients requiring dialysis in the form of SLED. Demographics, clinical, and biochemical variables were analyzed.

RESULTS

A total of 58 patients were enrolled in the study. The mean age was 48.58 ± 15 with a male-to-female ratio of 3:1. Higher APACHE II score, high international normalized ratio, thrombocytopenia, and septic shock were found to be poor prognostic markers, with an overall observed mortality of 56.9%.

CONCLUSION

SLED can be considered as an alternative to CCRT for selected hemodynamically unstable patients requiring renal replacement therapy.

Is SLED Efficient in Sepsis Associated Acute Kidney Injury: Hope but Hold!!

How to cite this article: Chhallani AA. Is SLED Efficient in Sepsis Associated Acute Kidney Injury: Hope but Hold!! Indian J Crit Care Med 2024;28(1):5-7.

Archetypal sustained low-efficiency daily diafiltration (SLEDD-f) for critically ill patients requiring kidney replacement therapy: towards an adequate therapy

Sustained low-efficiency dialysis is a hybrid form of kidney replacement therapy that has gained increasing popularity as an alternative to continuous forms of kidney replacement therapy in intensive care unit settings. During the COVID-19 pandemic, the shortage of continuous kidney replacement therapy equipment led to increasing usage of sustained low-efficiency dialysis as an alternative treatment for acute kidney injury. Sustained low-efficiency dialysis is an efficient method for treating hemodynamically unstable patients and is quite widely available, making it especially useful in resource-limited settings. In this review, we aim to discuss the various attributes of sustained low-efficiency dialysis and how it is comparable to continuous kidney replacement therapy in efficacy, in terms of solute kinetics and urea clearance, and the various formulae used to compare intermittent and continuous forms of kidney replacement therapy, along with hemodynamic stability. During the COVID-19 pandemic, there was increased clotting of continuous kidney replacement therapy circuits, which led to increased use of sustained low-efficiency dialysis alone or together with extra corporeal membrane oxygenation circuits. Although sustained low-efficiency dialysis can be delivered with continuous kidney replacement therapy machines, most centers use standard hemodialysis machines or batch dialysis systems. Even though antibiotic dosing differs between continuous kidney replacement therapy and sustained low-efficiency dialysis, reports of patient survival and renal recovery are similar for continuous kidney replacement therapy and sustained low-efficiency dialysis. Health care studies indicate that sustained low-efficiency dialysis has emerged as a cost-effective alternative to continuous kidney replacement therapy. Although there is considerable data to support sustained low-efficiency dialysis treatments for critically ill adult patients with acute kidney injury, there are fewer pediatric data, even so, currently available studies support the use of sustained low-efficiency dialysis for pediatric patients, particularly in resource-limited settings.

Prolonged Intermittent Kidney Replacement Therapy

Kidney replacement therapy (KRT) is a vital, supportive treatment for patients with critical illness and severe AKI. The optimal timing, dose, and modality of KRT have been studied extensively, but gaps in knowledge remain. With respect to modalities, continuous KRT and intermittent hemodialysis are well-established options, but prolonged intermittent KRT is becoming more prevalent worldwide, particularly in emerging countries. Compared with continuous KRT, prolonged intermittent KRT offers similar hemodynamic stability and overall cost savings, and its intermittent nature allows patients time off therapy for mobilization and procedures. When compared with intermittent hemodialysis, prolonged intermittent KRT offers more hemodynamic stability, particularly in patients who remain highly vulnerable to hypotension from aggressive ultrafiltration over a shorter duration of treatment. The prescription of prolonged intermittent KRT can be tailored to patients' progression in their recovery from critical illness, and the frequency, flow rates, and duration of treatment can be modified to avert hemodynamic instability during de-escalation of care. Dosing of prolonged intermittent KRT can be extrapolated from urea kinetics used to calculate clearance for continuous KRT and intermittent hemodialysis. Practice variations across institutions with respect to terminology, prescription, and dosing of prolonged intermittent KRT create significant challenges, especially in creating specific drug dosing recommendations during prolonged intermittent KRT. During the coronavirus disease 2019 pandemic, prolonged intermittent KRT was rapidly implemented to meet the KRT demands during patient surges in some of the medical centers overwhelmed by sheer volume of patients with AKI. Ideally, implementation of prolonged intermittent KRT at any institution should be conducted in a timely manner, with judicious planning and collaboration among nephrology, critical care, dialysis and intensive care nursing, and pharmacy leadership. Future analyses and clinical trials with respect to prescription and delivery of prolonged intermittent KRT and clinical outcomes will help to guide standardization of practice.

Sustained Low Efficiency Dialysis in Critically Ill Children With Acute Kidney Injury: Single-Center Observational Cohort in a Resource-Limited Setting

OBJECTIVES

To evaluate use of sustained low efficiency dialysis (SLED) in critically ill children with acute kidney injury in a resource-limited setting.

DESIGN

Observational database cohort study (December 2016 to January 2020).

SETTING

PICU of a tertiary hospital in India.

PATIENTS

Critically ill children undergoing SLED were included in the study.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Demographic and clinical data, prescription variables, hemodynamic status, complications, kidney, and patient outcomes of all children undergoing SLED in the PICU were analyzed. A total of 33 children received 103 sessions of SLED. The median (interquartile range, IQR) age and weight of children who received SLED were 9 years (4.5-12.8 yr) and 26 kg (15.2-34 kg), respectively. The most common diagnosis was sepsis with septic shock in 17 patients, and the mean (± sd ) Pediatric Risk of Mortality III score at admission was 11.8 (±6.4). The median (IQR) number and mean (± sd ) duration of inotropes per session were 3 hours (2-4 hr) and 96 (±82) hours, respectively. Of 103 sessions, the most common indication for SLED was oligoanuria with fluid overload and the need for creating space for fluid and nutritional support in 45 sessions (44%). The mean (± sd ) duration of SLED was 6.4 (±1.3) hours with 72 of 103 sessions requiring priming. The mean (± sd ) ultrafiltration rate per session achieved was 4.6 (±3) mL/kg/hr. There was significant decrease in urea and creatinine by end of SLED compared with the start, with mean change in urea and serum creatinine being 32.36 mg/dL (95% CI, 18.53-46.18 mg/dL) ( p < 0.001) and 0.70 mg/dL (95% CI, 0.35-1.06 mg/dL) ( p < 0.001), respectively. Complications were observed in 44 of 103 sessions, most common being intradialytic hypotension (21/103) and bleeding at the catheter site (21/103). Despite complications in one third of the sessions, only nine sessions were prematurely stopped, and 23 of 33 patients receiving SLED survived.

CONCLUSION

In critically ill children, our experience with SLED is that it is feasible and provides a viable form of kidney replacement therapy in a resource-limited setting.

Anticoagulation in patients with acute kidney injury undergoing kidney replacement therapy

Kidney replacement therapy (KRT) is used to provide supportive therapy for critically ill patients with severe acute kidney injury and various other non-renal indications. Modalities of KRT include continuous KRT (CKRT), intermittent hemodialysis (HD), and sustained low efficiency daily dialysis (SLED). However, circuit clotting is a major complication that has been investigated extensively. Extracorporeal circuit clotting can cause reduction in solute clearances and can cause blood loss, leading to an upsurge in treatment costs and a rise in workload intensity. In this educational review, we discuss the pathophysiology of the clotting cascade within an extracorporeal circuit and the use of various types of anticoagulant methods in various pediatric KRT modalities.

Intraoperative dialysis with the use of a mobile dialysis system during liver transplantation

PURPOSE

Over the last few years, transplant centers have started to use various intraoperative renal replacement therapy (ioRRT) modalities during liver transplantation (LT) in patients with pre-existing renal impairment. Here, we present a study on the safety and clinical outcomes of intraoperative hemodialysis (ioHD) performed using a mobile dialysis system during LT.

PATIENTS AND METHODS

We retrospectively analyzed 102 adult patients undergoing LT with ioHD; pre-existing renal failure and/or intraoperative metabolic derangement were ioHD treatment indications.

RESULTS

Our study cohort consisted of three groups: LT with preoperative serum creatinine (sCr) ​< ​2 ​mg/dL (Group 1:n ​= ​22), LT with preoperative sCr ≥2 ​mg/dL (Group 2:n ​= ​73), and simultaneous liver-kidney transplantation (Group 3:n ​= ​7). Among the procedures, 30% were re-transplantations. The mean calculated Model for End-stage Liver Disease score in Group 2 was 39.2, and 67% of patients were hospitalized in the intensive care unit. Patients in Group 1 were less acutely ill but developed severe intraoperative derangements and, therefore, underwent urgent ioHD intraoperatively. However, it was delayed when compared to Group 2. All groups achieved post-reperfusion potassium levels <4 ​mmol/L and a decrease in central venous pressure. No serious procedural complications occurred. Post-reperfusion syndrome occurred in 12.7% of patients. Elevated mortality was likely due to the high illness severity in the cohort.

CONCLUSIONS

Performing ioHD with a mobile dialysis system during LT was safe and effective, while being easier to perform than continuous techniques. Its effect on intra- and postoperative outcomes should be addressed in a study with a control group.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Practice Patterns for the Acceptance of Medically Complex Living Kidney Donors with Hematuria, Sickle Cell Trait, Smoking, Illegal Drug Use, or Urological Issues: A Multinational Survey

Background  To review the practice patterns for the acceptance of medically complex living kidney donors (MCLKD) among the transplant providers of the international transplant community. Methods  We distributed a survey globally, through major international transplantation societies, among nephrologists and transplant surgeons (TS). The survey contained questions regarding potential donors with microscopic hematuria, sickle cell trait, renal cysts, kidney stones, smoking, or illegal drug use. Results  There were 239 respondents from 29 countries, including nephrologists (42%) and TS (58%). Although most respondents would investigate microscopic hematuria, one-third of them indicated they would decline these potential donors without investigation. Interestingly, most respondents accepted heavy smokers, intermittent illegal drug users (with advice to quit), and those with incidentally identified kidney stones, remote history of renal colic or simple renal cysts. We found multiple areas of consensus in practice with some interesting differences between nephrologists and TS. Conclusions  This survey highlights the practice patterns of the acceptance of MCLKDs among the international community. In the absence of clear guidelines, this survey provides additional information to counsel kidney donors with microscopic hematuria, sickle cell trait, renal cysts, kidney stones, heavy smoking, or illegal drug use.

Impact of Cumulative Fluid Balance During Continuous Renal Replacement Therapy on Mortality in Patients With Septic Acute Kidney Injury: A Retrospective Cohort Study

Background: The clinicians often use continuous renal replacement therapy (CRRT) for the fluid management of patients with septic acute kidney injury (AKI). However, there is limited knowledge of the effects of changes in fluid balance (FB) on CRRT and its association with outcomes in patients with septic AKI.

Objective: This study aimed to determine the association of cumulative FB (CFB) during treatment with 28-day all-cause mortality in the patients with septic AKI who require CRRT.

Methods: This retrospective observational study examined patients who received CRRT due to septic AKI in a mixed intensive care unit (ICU) of a tertiary teaching hospital between January 2015 and December 2018. The patients were divided into three groups—negative FB, even FB, and positive FB—based on the CFB during CRRT. The primary outcome was 28-day all-cause mortality.

Results: We examined 227 eligible patients and the mean age was 62.4 ± 18.3 years. The even FB group had a significantly lower 28-day mortality (43.0%, p = 0.007) than the positive FB group (72.7%) and the negative FB group (54.8%). The unadjusted and adjusted Cox regression models indicated that the positive FB group had an increased risk for 28-day all-cause mortality relative to the even FB group. A restricted cubic splines model indicated a J-shaped association between the CFB and 28-day all-cause mortality in the unadjusted model.

Conclusion: Among the critically ill patients with septic AKI who require CRRT, those with positive FB had a higher mortality rate than those with even FB.

Which method of renal replacement therapy is best for patients with acute kidney injury in intensive care?

There are several methods of renal replacement therapy but none has a definitive survival benefit in patients with acute kidney injury. This article discusses the advantages and disadvantages of continuous and intermittent renal replacement for patients with acute kidney injury.

Intra-dialytic hypotension following the transition from continuous to intermittent renal replacement therapy

Background

Transition from continuous renal replacement therapy (CRRT) to intermittent renal replacement therapy (IRRT) can be associated with intra-dialytic hypotension (IDH) although data to inform the definition of IDH, its incidence and clinical implications, are lacking. We aimed to describe the incidence and factors associated with IDH during the first IRRT session following transition from CRRT and its association with hospital mortality. This was a retrospective single-center cohort study in patients with acute kidney injury for whom at least one CRRT-to-IRRT transition occurred while in intensive care. We assessed associations between multiple candidate definitions of IDH and hospital mortality. We then evaluated the factors associated with IDH.

Results

We evaluated 231 CRRT-to-IRRT transitions in 213 critically ill patients with AKI. Hospital mortality was 43.7% (n = 93). We defined IDH during the first IRRT session as 1) discontinuation of IRRT for hemodynamic instability; 2) any initiation or increase in vasopressor/inotropic agents or 3) a nadir systolic blood pressure of < 90 mmHg. IDH during the first IRRT session occurred in 50.2% of CRRT-to-IRRT transitions and was independently associated with hospital mortality (adjusted odds ratio [OR]: 2.71; CI 1.51–4.84, p < 0.001). Clinical variables at the time of CRRT discontinuation associated with IDH included vasopressor use, higher cumulative fluid balance, and lower urine output.

Conclusions

IDH events during CRRT-to-IRRT transition occurred in nearly half of patients and were independently associated with hospital mortality. We identified several characteristics that anticipate the development of IDH following the initiation of IRRT.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13613-021-00885-7.

The Effect of Renal Replacement Therapy and Antibiotic Dose on Antibiotic Concentrations in Critically Ill Patients: Data From the Multinational Sampling Antibiotics in Renal Replacement Therapy Study

BACKGROUND

The optimal dosing of antibiotics in critically ill patients receiving renal replacement therapy (RRT) remains unclear. In this study, we describe the variability in RRT techniques and antibiotic dosing in critically ill patients receiving RRT and relate observed trough antibiotic concentrations to optimal targets.

METHODS

We performed a prospective, observational, multinational, pharmacokinetic study in 29 intensive care units from 14 countries. We collected demographic, clinical, and RRT data. We measured trough antibiotic concentrations of meropenem, piperacillin-tazobactam, and vancomycin and related them to high- and low-target trough concentrations.

RESULTS

We studied 381 patients and obtained 508 trough antibiotic concentrations. There was wide variability (4-8-fold) in antibiotic dosing regimens, RRT prescription, and estimated endogenous renal function. The overall median estimated total renal clearance (eTRCL) was 50 mL/minute (interquartile range [IQR], 35-65) and higher eTRCL was associated with lower trough concentrations for all antibiotics (P < .05). The median (IQR) trough concentration for meropenem was 12.1 mg/L (7.9-18.8), piperacillin was 78.6 mg/L (49.5-127.3), tazobactam was 9.5 mg/L (6.3-14.2), and vancomycin was 14.3 mg/L (11.6-21.8). Trough concentrations failed to meet optimal higher limits in 26%, 36%, and 72% and optimal lower limits in 4%, 4%, and 55% of patients for meropenem, piperacillin, and vancomycin, respectively.

CONCLUSIONS

In critically ill patients treated with RRT, antibiotic dosing regimens, RRT prescription, and eTRCL varied markedly and resulted in highly variable antibiotic concentrations that failed to meet therapeutic targets in many patients.

The impact of continuous renal replacement therapy on antibiotic pharmacokinetics in critically ill patients

Introduction: Mortality due to severe infections in critically ill patients undergoing continuous renal replacement therapy (CRRT) remains high. Nevertheless, rapid administration of adequate antibiotic therapy can improve survival. Delivering optimized antibiotic therapy can be a challenge, as standard drug regimens often result in insufficient or excessive serum concentrations due to significant changes in the volume of distribution and/or drug clearance in these patients. Insufficient drug concentrations can be responsible for therapeutic failure and death, while excessive concentrations can cause toxic adverse events.Areas covered: We performed a narrative review of the impact of CRRT on the pharmacokinetics of the most frequently used antibiotics in critically ill patients. We have provided explanations for the changes in the PKs of antibiotics observed and suggestions to optimize dosage regimens in these patients.Expert opinion: Despite considerable efforts to identify optimal antibiotic dosage regimens for critically ill patients receiving CRRT, adequate target achievement remains too low for hydrophilic antibiotics in many patients. Whenever possible, individualized therapy based on results from therapeutic drug monitoring must be given to avoid undertreatment or toxicity.

Short-and long-term outcomes of sustained low efficiency dialysis vs continuous renal replacement therapy in critically ill patients with acute kidney injury

BACKGROUND

Sustained low efficiency dialysis (SLED) has emerged as an alternative to continuous renal replacement therapy (CRRT) for the treatment of acute kidney injury (AKI) in critically ill patients. However, there is limited information on the short- and long-term outcomes of SLED compared to CRRT.

METHODS

We conducted a retrospective cohort study of patients with AKI who commenced either SLED or CRRT in ICUs at a tertiary care hospital in Toronto, Canada. The primary outcome was 90-day all-cause mortality. Secondary outcomes included mortality at one year, and dialysis dependence at 90 days and one year. All outcomes were ascertained by linkage to provincial datasets.

RESULTS

We identified 284 patients, of whom 95 and 189 commenced SLED and CRRT, respectively. Compared to SLED recipients, more CRRT recipients were mechanically ventilated (96% vs 86%, p = 0.002) and receiving vasopressors (94% vs 84%, p = 0.01) at the time of RRT initiation. At 90 days following RRT initiation, 52 (55%) and 126 (67%) SLED and CRRT recipients, respectively, died (adjusted risk ratio (RR) 0.91, 95% CI 0.75-1.11). There was no inter-modality difference in time to death through 90 days (adjusted hazard ratio 0.90, 95% CI 0.64-1.27). Among patients surviving to Day 90, a higher proportion of SLED recipients remained RRT dependent (10 (23%) vs 6 (10%) CRRT recipients, adjusted RR 2.82, 95% CI 1.02-7.81). At one year, there was no difference in mortality or dialysis dependence.

CONCLUSIONS

Among critically ill patients with acute kidney injury, mortality at 90 days and one year was not different among patients initiating SLED as compared to CRRT.

Deployment of a New CRRT/PIRRT Device during the COVID-19 Pandemic Emergency: Organizational Challenges and Implementation Results

INTRODUCTION

The coronavirus disease 2019 (COVID-19) pandemic led to increased demand nationwide for dialysis equipment, including supplies and machines. To meet the demand in our institution, our surge plan included rapid mobilization of a novel continuous renal replacement treatment (CRRT) machine named SAMI. The SAMI is a push-pull filtration enhanced dialysis machine that can conjugate extremely high single-pass solute removal efficiency with very precise fluid balance control.

MATERIAL AND METHODS

Machine assembly was conducted on-site by local biomedical engineers with remote assistance by the vendor. One 3-h virtual training session of 3 dialysis nurses was conducted before SAMI deployment. The SAMI was deployed in prolonged intermittent replacement therapy (PIRRT) mode to maximize patients covered per machine per day. Live on-demand vendor support was provided to troubleshoot any issues for the first few cases. After 4 weeks of the SAMI implementation, data on treatments with the SAMI were collected, and a questionnaire was provided to the nurse trainees to assess device usability.

RESULTS

On-site installation of the SAMI was accomplished with remote assistance. Delivery of remote training was successfully achieved. 23 PIRRT treatments were conducted in 10 patients. 7/10 of patients had CO-VID-19. The median PIRRT dose was 50 mL/kg/h (IQR [interquartile range] 44 - 62 mL/kg/h), and duration of the treatment was 8 h (IQR 6.3 - 8 h). Solute control was adequate. The user response was favorable to the set of usability questions involving user interface, on-screen instructions, machine setup, troubleshooting, and the ease of moving the machine.

CONCLUSION

Assembly of the SAMI and training of nurses remotely are possible when access to vendor employees is restricted during states of emergency. The successful deployment of the SAMI in our institution during the pandemic with only 3-h virtual training supports that operating the SAMI is simple and safe.

Acute Renal Replacement Therapy in Intensive Care Units versus Outside Intensive Care Units: Are They Different?

Introduction

Acute renal replacement therapy (RRT) is indicated when metabolic and fluid demands exceed total kidney capacity, and demand for kidney function is determined by non-renal comorbidities, severity of acute disease and solute and fluid burden; therefore, the criteria for commencing RRT and dialysis in intensive care units (ICUs) may be different to those outside ICUs.

Objective

We investigated whether criteria for commencing acute RRT and dialysis outside ICU were different to those in ICU and whether these differences affected patient mortality in either setting.

Methods

We performed a retrospective observational study evaluating acute kidney injury (AKI), Kidney Disease Improving Global Outcome 3 (KDIGO3) in adult patients undergoing RRT “in and outside” ICU from 2012 to 2018, in a Brazilian teaching hospital.

Results

We evaluated 913 adults with AKI KDIGO3 undergoing RRT; 629 (68.9%) outside ICU and 284 (31.1%) in ICU. Infections were the main cause of hospitalisation (34.4%). Septic and ischaemic AKI were the main aetiologies of AKI (50.8% and 32.9%, respectively), metabolic and fluid demand to capacity imbalance were the main indications for dialysis (69.7%), and intermittent haemodialysis (IHD) was the primary dialysis method (59.2%). The general mortality rate after 30 days was 59%. There were no differences in gender, age and main diagnosis between groups. Both groups were different in acute tubular necrosis index specific scores (ATN-ISS), AKI aetiology, elderly population, indications for dialysis, dialysis methods and mortality rates. In ICU, patients older than 65 years old, with septic AKI were more prevalent (49.1 versus 41.4%, and 55.1 versus 37.5%, respectively), while ischaemic and nephrotoxic AKI were less frequent (24.3 versus 37 and 10.2 versus 16.3%, respectively), and ATN-ISS was higher (0.74 ± 0.31 versus 0.58 ± 0.16). Similarly, metabolic and fluid demand to capacity imbalance as an indication for acute RRT, prolonged intermittent haemodialysis (PIRRT) and continuous renal replacement therapy (CRRT) were more frequent, while peritoneal dialysis (PD) was less frequent (74.6 versus 69.7%, 31.6 versus 22.4%, and 5.3 versus 17.8%, respectively), and mortality was higher (69 versus 54.7%, respectively). Logistic regression revealed that age, septic AKI and being “in” ICU were factors associated with death.

Conclusion

The criteria for commencing RRT and dialysis in ICU were different to those outside ICU; however, they did not impact on patient outcomes.

Changing the terminology from kidney replacement therapy to kidney support therapy

Kidney replacement therapy (KRT) is a common supportive treatment for renal dysfunction, especially acute kidney injury. However, critically ill or immunosuppressed patients with renal dysfunction often have dysfunction in other organs as well. To improve patient outcomes, clinicians began to initiate kidney replacement therapy in situations where nonrenal conditions may lead to acute kidney injury, such as septic shock, hematopoietic stem cell transplantation, veno-occlusive renal disease, cardiopulmonary bypass, chemotherapy, tumor lysis syndrome, hyperammonemia, and various others. In this review, we discuss the use of various modes of kidney replacement therapy in treating renal and nonrenal complications to illustrate why kidney support therapy is a more appropriate terminology than kidney replacement therapy.

Contemporary Management of Severe Acute Kidney Injury and Refractory Cardiorenal Syndrome: JACC Council Perspectives

Acute kidney injury (AKI) and cardiorenal syndrome (CRS) are increasingly prevalent in hospitalized patients with cardiovascular disease and remain associated with poor short- and long-term outcomes. There are no specific therapies to reduce mortality related to either AKI or CRS, apart from supportive care and volume status management. Acute renal replacement therapies (RRTs), including ultrafiltration, intermittent hemodialysis, and continuous RRT are used to manage complications of medically refractory AKI and CRS and may restore normal electrolyte, acid-base, and fluid balance before renal recovery. Patients who require acute RRT have a significant risk of mortality and long-term dialysis dependence, emphasizing the importance of appropriate patient selection. Despite the growing use of RRT in the cardiac intensive care unit, there are few resources for the cardiovascular specialist that integrate the epidemiology, diagnostic workup, and medical management of AKI and CRS with an overview of indications, multidisciplinary team management, and transition off of RRT.

Characteristics and Clinical Outcomes of Prolonged Continuous Renal Replacement Therapy in Critically Ill Pediatric Patients

OBJECTIVES

Paralleling improved outcomes in critically ill patients, survival for pediatric acute kidney injury has improved. Continuous renal replacement therapy is the preferred modality to optimize fluid and electrolyte management as well as nutritional support for children developing acute kidney injury in the PICU. However, some patients remain too fragile for transition to intermittent renal replacement therapies and require continuous renal replacement therapy for a prolonged period. Characteristics of this cohort and factors impacting outcomes are not well known. We aimed to describe the characteristics of pediatric patients requiring prolonged continuous renal replacement therapy and evaluate the factors impacting hospital survival.

DESIGN

Retrospective chart review.

SETTING

Tertiary PICU.

PATIENTS

Children requiring prolonged continuous renal replacement therapy. Prolonged continuous renal replacement therapy was defined as continuous renal replacement therapy dependence greater than or equal to 28 days. Primary outcome was hospital mortality.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

From 2013 to 2016, 344 patients received continuous renal replacement therapy, 36 (10%) received continuous renal replacement therapy for greater than or equal to 28 days. Seventeen patients (47%) were female. Overall mortality was 44% (16/36); 69% (11/16) of nonsurvivors died of sepsis. Pediatric Logistic Organ Dysfunction score was significantly higher in nonsurvivors. Mortality rate was significantly higher in patients who were neutropenic at continuous renal replacement therapy start. Neutropenia (defined as absolute neutrophil count < 1,500/mm) at continuous renal replacement therapy start was the only independent predictor of mortality. One in four survivors did not recover renal function and remained dialysis dependent.

CONCLUSIONS

Prolonged continuous renal replacement therapy patients are at high risk of nonrecovery of renal function and require close monitoring. The majority of nonsurvivors in the study group died from sepsis. Neutropenia at continuous renal replacement therapy initiation was associated with increased risk of mortality. Progression of underlying disease process could explain the higher death rate in patients with neutropenia; however, inadequate treatment of infectious complications could be another explanation to explore further in future studies.

Effect of renal replacement therapy modalities on renal recovery and mortality for acute kidney injury: A PRISMA-compliant systematic review and meta-analysis

Previous investigations showed inconsistent results for comparison in renal recovery, in-hospital, and in-intensive care unit (ICU) mortalities between acute kidney injury (AKI) patients treated with continuous renal replacement therapy (CRRT) and some kinds of intermittent renal replacement therapies (IRRTs). We systematically searched for articles published in the databases (PubMed, Web of Science, EMBASE, Medline, and Google Scholar) until June 2019. We made all statistical analysis using STATA 12.0 software. In the present meta-analysis, relative risks with 95% confidence intervals were calculated for binary outcomes (renal recovery status or mortality). The present study indicated no significant differences in renal recovery, in-hospital mortality, and in-ICU mortality between AKI patients given CRRT and those given sustained low-efficiency dialysis (SLED). Additionally, the study showed no significant difference in in-hospital mortality between AKI patients given CRRT and those given intermittent hemodialysis (IHD), whereas elevated in-ICU mortality was detected in AKI patients given CRRT, compared to those given IHD. The three modalities (CRRT, IHD, and SLED) have their own advantages and disadvantages. More rigorous trials design with large cohort should be made to explore the differences in renal recovery, in-hospital, and in-ICU mortalities between different kinds of RRTs.

Sustained low-efficiency diafiltration is superior to hemodialysis in promoting renal function recovery in elderly wasp sting victims with stage III acute kidney injury: a retrospective study

Objective: To study the efficacy and safety of sustained low-efficiency diafiltration (SLEDf) versus hemodialysis (HD) for patients with wasp stings who developed stage III acute kidney injury (AKI).

Methods: We retrospectively analyzed the clinical data of consecutive patients who developed AKI following wasp stings. All eligible patients received renal replacement therapy in combination with hemoperfusion. Thereafter, blood purification therapy and HD were performed with a volumetrically controlled machine and 1.7 m² surface, Fresenius Polysulfone HD filter and SLEDf was undertaken with a volumetrically controlled machine and 1.3 m² surface, Fresenius Polysulfone HD filter.

Results: Forty patients developed stage III AKI following wasp stings, including 14 patients that received SLEDf and 26 patients underwent HD. Thirteen patients were aged less than 60 years and underwent HD (group I), 27 patients were aged at least 60 years, including 13 patients undergoing HD (group II) and 14 patients receiving SLEDf (group III). Groups I and II completed 150 and 162 sessions of HD, respectively, and group III completed 156 sessions of sustained low-efficiency blood purification therapy, including 50 sessions of SLEDf. The time to return to normal serum creatinine levels was 38.8 ± 2.7 days for group I, 47.2 ± 5.3 days for group II, and 39.2 ± 3.3 days for group III. A statistically significant difference was observed in time to normal serum creatinine levels among the three groups.

Conclusion: Elderly wasp victims have more severe illness than younger wasp victims and SLEDf is safe and superior to HD in recovery of renal function of elderly wasp victims.

Renal replacement therapy for acute kidney injury in intensive care

Acute kidney injury is a common occurrence on the intensive care unit and is associated with incremental risk of death and chronic kidney disease. Renal replacement therapy has become an essential tool in the intensive care management of patients with severe acute kidney injury and its use is rising. A basic understanding of renal replacement therapy is essential for all doctors treating acutely unwell patients. This article provides a brief overview of the principles and important considerations for the provision of renal replacement therapy for critically ill patients with acute kidney injury.

Renal Replacement Therapy in Acute Kidney Injury: Which Mode and When?

Renal replacement therapy (RRT) for acute kidney injury (AKI) patients in an intensive care unit (ICU) presents unique problems of providing biochemical and fluid removal in patients with unstable circulations, inotropes, and increased capillary permeability. Although no individual modality has been shown to confer a mortality benefit, it is assumed that continuous therapies like peritoneal dialysis (PD) and venovenous hemofiltration or hemodiafiltration may be better tolerated by the patient with hemodynamic instability, raised intracranial pressure (ICP), and liver failure. An individual patient may require more than one treatment in the course of his/her illness. The therapies offered may reflect available resources, local expertise, and cost constraints.

Predicting mortality among critically ill patients with acute kidney injury treated with renal replacement therapy: Development and validation of new prediction models

PURPOSE

Severe acute kidney injury (AKI) is associated with a significant risk of mortality and persistent renal replacement therapy (RRT) dependence. The objective of this study was to develop prediction models for mortality at 90-day and 1-year following RRT initiation in critically ill patients with AKI.

METHODS

All patients who commenced RRT in the intensive care unit for AKI at a tertiary care hospital between 2007 and 2014 constituted the development cohort. We evaluated the external validity of our mortality models using data from the multicentre OPTIMAL-AKI study.

RESULTS

The development cohort consisted of 594 patients, of whom 320(54%) died and 40 (15% of surviving patients) remained RRT-dependent at 90-day Eleven variables were included in the model to predict 90-day mortality (AUC:0.79, 95%CI:0.76-0.82). The performance of the 90-day mortality model declined upon validation in the OPTIMAL-AKI cohort (AUC:0.61, 95%CI:0.54-0.69) and showed modest calibration. Similar results were obtained for mortality model at 1-year.

CONCLUSIONS

Routinely collected variables at the time of RRT initiation have limited ability to predict mortality in critically ill patients with AKI who commence RRT.

Evaluation on treatment of sustained low-efficiency hemodialysis against patients with multiple organ dysfunction syndrome following wasp stings

Background

To evaluate the treatment of sustained low-efficiency hemodialysis (SLED) against patients with multiple organ dysfunction syndrome (MODS) following wasp stings.

Methods

Clinical data of 35 patients with MODS following wasp stings were retrospectively analysed. These patients were divided into three groups according to the treatment strategy used: 1) hemodialysis (HD) group, 2) continuous veno-venous hemofiltration (CVVH)/HD group, and 3) SLED/HD group. The clinical parameters, treatment outcome, and safety findings were compared among the three groups.

Results

The recovery rate (76.92% vs 77.78% vs 91.67%, p = 0.621) and mortality rate (15.38% vs 11.11% vs 8.33%, p = 0.999) were similar among the three groups. When compared to the HD group, patients treated with CVVH/HD or SLED/HD required a shorter period of time to enter into polyuria stage [(24.7 ± 4.3) days vs (20.2 ± 4.7) days vs (18.2 ± 3.0) days, F = 9.11, p = 0.0007], and required a shorter time for serum creatinine to return to normal [(45.7 ± 13.4) days vs (33.1 ± 9.4) days vs (31.9 ± 9.8), F = 5.83, p = 0.0069]; while such parameters had no significant differences between SLED/HD group and CVVH/HD group. The adverse events of hypotension and arrhythmia were found in the HD group, while no adverse events were reported in the SLED/HD and CVVH/HD groups. There was no significant difference in the cost of blood purification treatment between the SLED/HD group and HD group.

Conclusion

The use of SLED, CVVH and HD provided a comparable recovery and survival rates in patients with MODS secondary to wasp stings. Compared to HD, the use of SLED is recommended as a treatment strategy because of the efficacy on recover of renal function, satisfactory safety outcome, as well as the reasonable treatment cost.

Mortality and Recovery of Renal Function in Acute Kidney Injury Patients Treated with Prolonged Intermittent Hemodialysis Sessions Lasting 10 versus 6 Hours: Results of a Randomized Clinical Trial

PURPOSE

This trial aimed to compare mortality and recovery of renal function in acute kidney injury (AKI) patients treated with different durations of prolonged hemodialysis (PHD) sessions (6 h versus 10 h).

METHODOLOGY

We included patients with sepsis-associated AKI, >18 years, who are in use of a norepinephrine (lower than 0.7 ucg/kg/min).

RESULTS

One hundred and ninety-four patients were treated with 531 sessions of PHD (G1=104 and G2=90 patients). The two groups were similar in age and SOFA. There was no significant difference in hypotension, hypokalemia, and anticoagulation during PHD sessions. The two groups showed differences in filter clotting, hypophosphatemia, and treatment discontinuation (12.3 versus 23.1%, p=0.002; 15.5 versus 25.8%, p=0.005; and 7.9 versus 15.6%, p=0.008, respectively). There was no difference in fluid balance (FB) before and after PHD sessions. Death and complete recovery of renal function were similar (81.3 versus 82.2%, p=0.87 and 21 versus 31.2%, p=0.7, respectively). At logistic regression, the positive FB before and after dialysis was identified as risk factor for death, while volume overload after three PHD sessions and predialysis creatinine were negatively associated with recovery of renal function in 28 days.

CONCLUSION

There was no difference in the mortality and recovery of renal function of AKI patients submitted to different durations of PHD and sessions lasting 10 h presented higher filter clotting, hypophosphatemia, and treatment discontinuation. ISRCTN Registry number is ISRCTN33774458.

Prolonged intermittent renal replacement therapy in children

Wide ranges of age and weight in pediatric patients makes renal replacement therapy (RRT) in acute kidney injury (AKI) challenging, particularly in the pediatric intensive care unit (PICU), wherein children are often hemodynamically unstable. Standard hemodialysis (HD) is difficult in this group of children and continuous veno-venous hemofiltration/dialysis (CVVH/D) has been the accepted modality in the developed world. Unfortunately, due to cost constraints, CVVH/D is often not available and peritoneal dialysis (PD) remains the common mode of RRT in resource-poor facilities. Acute PD has its drawbacks, and intermittent HD (IHD) done slowly over a prolonged period has been explored as an alternative. Various modes of slow sustained IHD have been described in the literature with the recently introduced term prolonged intermittent RRT (PIRRT) serving as an umbrella terminology for all of these modes. PIRRT has been widely accepted in adults with studies showing it to be as effective as CVVH/D but with an added advantage of being more cost-effective. Pediatric data, though scanty, has been promising. In this current review, we elaborate on the practical aspects of undertaking PIRRT in children as well as summarize its current status.

Biomarkers of renal recovery after acute kidney injury

Novel biomarkers can be suitable for early acute kidney injury diagnosis and the prediction of the need for dialysis. It remains unclear whether such biomarkers may also play a role in the prediction of recovery after established acute kidney injury or in aiding the decision of when to stop renal support therapy. PubMed, Web of Science and Google Scholar were searched for studies that reported on the epidemiology of renal recovery after acute kidney injury, the risk factors of recovery versus non-recovery after acute kidney injury, and potential biomarkers of acute kidney injury recovery. The reference lists of these articles and relevant review articles were also reviewed. Final references were selected for inclusion in the review based on their relevance. New biomarkers exhibited a potential role in the early diagnosis of acute kidney injury recovery. Urine HGF, IGFBP-7, TIMP-2 and NGAL may improve our ability to predict the odds and timing of recovery and eventually renal support withdrawal. Acute kidney injury recovery requires more study, and its definition needs to be standardized to allow for better and more powerful research on biomarkers because some of them show potential for the prediction of acute kidney injury recovery.

Interventions to prevent hemodynamic instability during renal replacement therapy in critically ill patients: a systematic review

Background

Hemodynamic instability related to renal replacement therapy (HIRRT) may increase the risk of death and limit renal recovery. Studies in end-stage renal disease populations on maintenance hemodialysis suggest that some renal replacement therapy (RRT)-related interventions (e.g., cool dialysate) may reduce the occurrence of HIRRT, but less is known about interventions to prevent HIRRT in critically ill patients receiving RRT for acute kidney injury (AKI). We sought to evaluate the effectiveness of RRT-related interventions for reducing HIRRT in such patients across RRT modalities.

Methods

A systematic review of publications was undertaken using MEDLINE, MEDLINE in Process, EMBASE, and Cochrane’s Central Registry for Randomized Controlled Trials (RCTs). Studies that assessed any intervention’s effect on HIRRT (the primary outcome) in critically ill patients with AKI were included. HIRRT was variably defined according to each study’s definition. Two reviewers independently screened abstracts, identified articles for inclusion, extracted data, and evaluated study quality using validated assessment tools.

Results

Five RCTs and four observational studies were included (n = 9; 623 patients in total). Studies were small, and the quality was mostly low. Interventions included dialysate sodium modeling (n = 3), ultrafiltration profiling (n = 2), blood volume (n = 2) and temperature control (n = 3), duration of RRT (n = 1), and slow blood flow rate at initiation (n = 1). Some studies applied more than one strategy simultaneously (n = 5). Interventions shown to reduce HIRRT from three studies (two RCTs and one observational study) included higher dialysate sodium concentration, lower dialysate temperature, variable ultrafiltration rates, or a combination of strategies. Interventions not found to have an effect included blood volume and temperature control, extended duration of intermittent RRT, and slower blood flow rates during continuous RRT initiation. How HIRRT was defined and its frequency of occurrence varied widely across studies, including those involving the same RRT modality. Pooled analysis was not possible due to study heterogeneity.

Conclusions

Small clinical studies suggest that higher dialysate sodium, lower temperature, individualized ultrafiltration rates, or a combination of these strategies may reduce the risk of HIRRT. Overall, for all RRT modalities, there is a paucity of high-quality data regarding interventions to reduce the occurrence of HIRRT in critically ill patients.

Electronic supplementary material

The online version of this article (10.1186/s13054-018-1965-5) contains supplementary material, which is available to authorized users.

Risk Factor Analysis for AKI Including Laboratory Indicators: a Nationwide Multicenter Study of Hospitalized Patients

BACKGROUND/AIMS

Risk factor studies for acute kidney injury (AKI) in China are lacking, especially those regarding non-traditional risk factors, such as laboratory indicators.

METHODS

All adult patients admitted to 38 tertiary and 22 secondary hospitals in China in any one month between July and December 2014 were surveyed. AKI patients were screened according to the Kidney Disease: Improving Global Outcomes' definition of AKI. Logistic regression was used to analyze the risk factors for AKI, and Cox regression was used to analyze the risk of in-hospital mortality for AKI patients; additionally, a propensity score analysis was used to reconfirm the risk factors among laboratory indicators for mortality.

RESULTS

The morbidity of AKI was 0.97%. Independent risk factors for AKI were advancing age, male gender, hypertension, and chronic kidney disease. All-cause mortality was 16.5%. The predictors of mortality in AKI patients were advancing age, tumor, higher uric acid level and increases in Acute Physiologic Assessment and Chronic Health Evaluation II and Sequential Organ Failure Assessment scores. The hazard ratio (HR) for mortality with uric acid levels > 9.1 mg/dl compared with ≤ 5.2 mg/dl was 1.78 (95% CI: 1.23 to 2.58) for the AKI patients as a group, and was 1.73 (95% CI: 1.24 to 2.42) for a propensity score-matched set.

CONCLUSION

In addition to traditional risk factors, uric acid level is an independent predictor of all-cause mortality after AKI.

A Study of Continuous Renal Replacement Therapy and Acute Peritoneal Dialysis in Hemodynamic Unstable Patients

Objective:

The objective of the following study was to assess the outcome of continuous renal replacement therapy (CRRT) and acute peritoneal dialysis (PD) in dialysis-requiring renal failure in patients with hemodynamic instability.

Materials and Methods:

A retrospective analysis of all the patients who received CRRT and acute PD over a period of 1 year at our institute, a tertiary care center, was done for diagnosis, type of renal replacement therapy (RRT), and survival outcome. The indications for administering either of the therapy were usual indications of doing hemodialysis with the presence of hemodynamic instability (systolic blood pressure <90 mm of Hg even with inotropes).

Results:

Forty patients, 22 in CRRT and 18 in acute PD group were studied. All these patients required inotropes to maintain desired blood pressure. Twenty-five (62.5%) patients had acute kidney injury (AKI), and 15 (37.5%) had chronic kidney disease (CKD) superimposed over other primary diagnosis. A total of 8 (20%) patients (4 in CRRT, 4 in acute PD) survived at the time of discharge from hospital. The mean age of survivors was approximately a decade less than nonsurvivors (P = 0.15). Overall, there were no survivors in CKD group and all the patients who survived at the time of discharge from hospital had underlying AKI (P = 0.016).

Conclusion:

This study showing comparable survival outcome in acute PD and CRRT gives evidence that either of the modalities can be adopted in hemodynamically unstable patients requiring RRT depending on the resources available.

Trends in One-Year Outcomes of Dialysis-Requiring Acute Kidney Injury in Denmark 2005-2012: A Population-Based Nationwide Study

BACKGROUND

Dialysis-requiring acute kidney injury (AKI) is associated with substantial mortality and risk of end-stage renal disease (ESRD). Despite considerable growth in incidence of severe AKI, information pertaining to trends in outcomes remains limited. We evaluated time trends in one year risks of ESRD and death in patients with dialysis-requiring AKI over an eight year period in Denmark.

METHODS

In a retrospective nationwide study based on national registers, all adults requiring acute renal replacement therapy between 2005 and 2012 were identified. Patients with preceding ESRD were excluded. Through individual-level cross-referencing of administrative registries, information pertaining to comorbidity, preceding surgical interventions, and concurrent other organ failure and sepsis was ascertained. Comparisons of period-specific one year odds ratios for ESRD and death were calculated in a multiple logistic regression model.

RESULTS

A total of 13,819 patients with dialysis-requiring AKI were included in the study. Within one year, 1,017 (7.4%) patients were registered with ESRD, and 7,908 (57.2%) patients died. The one-year rate of ESRD decreased from 9.0% between 2005 and 2006 to 6.1% between 2011 and 2012. Simultaneously, the one-year mortality rate decreased from 58.2% between 2005 and 2006 to 57.5% between 2011 and 2012. Consequently, the adjusted odds ratios for the period 2011-2012 (with the period 2005-2006 as reference) were 0.75 (0.60-0.95, p = 0.015) and 0.87 (95% CI 0.78-0.97, p = 0.010) for ESRD and death, respectively.

CONCLUSIONS

In a nationwide retrospective study on time trends in one year outcomes following dialysis-requiring AKI, risk of all-cause mortality and ESRD decreased over a period of 8 years.

Prolonged Intermittent Renal Replacement Therapy

Prolonged intermittent renal replacement therapy (PIRRT) is becoming an increasingly popular alternative to continuous renal replacement therapy in critically ill patients with acute kidney injury. There are significant practice variations in the provision of PIRRT across institutions, with respect to prescription, technology, and delivery of therapy. Clinical trials have generally demonstrated that PIRRT is non-inferior to continuous renal replacement therapy regarding patient outcomes. PIRRT offers cost-effective renal replacement therapy along with other advantages such as early patient mobilization and decreased nursing time. However, due to lack of standardization of the procedure, PIRRT still poses significant challenges, especially pertaining to appropriate drug dosing. Future guidelines and clinical trials should work toward developing consensus definitions for PIRRT and ensure optimal delivery of therapy.