Prolonged Intermittent Renal Replacement Therapy

The pharmacokinetics of ganciclovir during prolonged intermittent kidney replacement therapy in a cardiac transplant recipient

Ganciclovir, a guanine analogue, is used intravenously (IV) first-line for the prophylaxis and treatment of cytomegalovirus (CMV) infection in solid organ transplant recipients. The pharmacokinetics (PK) of ganciclovir are highly variable, with myelosuppression occurring at high concentrations. Ganciclovir is primarily renally excreted as the parent compound, and clearance is significantly reduced in renal impairment. Acute kidney injury (AKI) is a common post-operative complication of cardiac transplantation, reducing the clearance of ganciclovir. In the intensive care unit (ICU), AKI is often managed by kidney replacement therapy (KRT). One form of KRT, prolonged intermittent kidney replacement therapy (PIKRT) is increasingly used for cost and flexibility advantages. Ganciclovir dosing recommendations are available for varying degrees of renal impairment and KRT, except for PIKRT. In this case of cardiac transplantation, complicated by anuric AKI, a ganciclovir dose of 2.0-2.5 mg/kg of adjusted body weight given after each PIKRT session was demonstrated to achieve PK targets.

Removal of common antimicrobial agents by sustained low-efficiency dialysis

Adequate dosing of antimicrobials is paramount for treating infections in critically ill patients undergoing kidney replacement therapy; however, little is known about antimicrobial removal by sustained low-efficiency dialysis (SLED). The objective was to quantify the removal of cefepime, daptomycin, meropenem, piperacillin-tazobactam, and vancomycin in patients undergoing SLED. Adult patients ≥18 years with acute kidney injury (AKI) or end-stage kidney disease receiving one of the select antimicrobials and requiring SLED were included. Blood and dialysate flow rates were maintained at 250 and 100 mL/min, respectively. Simultaneous arterial and venous blood samples for the analysis of antibiotic concentrations were collected hourly for 8 hours during SLED (on-SLED). Arterial samples were collected every 2 hours for up to 6 hours while not receiving SLED (off-SLED) for the calculation of SLED clearance, half-life (t1/2) on-SLED and off-SLED, and the fraction of removal by SLED (fD). Twenty-one patients completed the study: 52% male, mean age (±SD) 53 ± 13 years, and mean weight of 98 ± 30 kg. Eighty-six percent had AKI, and 4 patients were receiving cefepime, 3 daptomycin, 10 meropenem, 6 piperacillin-tazobactam, and 13 vancomycin. The average SLED time was 7.3 ± 1.1 hours, and the mean ultrafiltration rate was 95 ± 52 mL/hour (range 10-211). The t1/2 on-SLED was substantially lower than the off-SLED t1/2 for all antimicrobials, and the SLED fD varied between 44% and 77%. An 8-hour SLED session led to significant elimination of most antimicrobials evaluated. If SLED is performed, modification of the dosing regimen is warranted to avoid subtherapeutic concentrations.

Vancomycin removal and pharmacokinetics during accelerated venovenous hemofiltration

INTRODUCTION

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

OBJECTIVE

To describe the removal and pharmacokinetics of vancomycin during AVVH.

METHODS

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

RESULTS

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

CONCLUSION

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

Nomenclature of Extracorporeal Blood Purification Therapies for Acute Indications: The Nomenclature Standardization Conference

The development of new extracorporeal blood purification (EBP) techniques has led to increased application in clinical practice but also inconsistencies in nomenclature and misunderstanding. In November 2022, an international consensus conference was held to establish consensus on the terminology of EBP therapies. It was agreed to define EBP therapies as techniques that use an extracorporeal circuit to remove and/or modulate circulating substances to achieve physiological homeostasis, including support of the function of specific organs and/or detoxification. Specific acute EBP techniques include renal replacement therapy, isolated ultrafiltration, hemoadsorption, and plasma therapies, all of which can be applied in isolation and combination. This paper summarizes the proposed nomenclature of EBP therapies and serves as a framework for clinical practice and future research.

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.

Switching from continuous veno-venous hemodiafiltration to intermittent sustained low-efficiency daily hemodiafiltration (SLED-f) in pediatric acute kidney injury: A prospective cohort study

INTRODUCTION

Continuous kidney replacement therapy (CKRT) is the preferred modality in critically ill children with acute kidney injury. Upon improvement, intermittent hemodialysis is usually initiated as a step-down therapy, which can be associated with several adverse events. Hybrid therapies such as Sustained low-efficiency daily dialysis with pre-filter replacement (SLED-f) combines the slow sustained features of a continuous treatment, ensuring hemodynamic stability, with similar solute clearance along with the cost effectiveness of conventional intermittent hemodialysis. We examined the feasibility of using SLED-f as a transition step-down therapy after CKRT in critically ill pediatric patients with acute kidney injury.

METHODS

A prospective cohort study was conducted in children admitted to our tertiary care pediatric intensive care units with multi-organ dysfunction syndrome including acute kidney injury who received CKRT for management. Those patients receiving fewer than two inotropes to maintain perfusion and failed a diuretic challenge were switched to SLED-f.

RESULTS

Eleven patients underwent 105 SLED-f sessions (mean of 9.55 +/- 4.90 sessions per patient), as a part of step-down therapy from continuous hemodiafiltration. All (100%) our patients had sepsis associated acute kidney injury with multiorgan dysfunction and required ventilation. During SLED-f, urea reduction ratio was 64.1 +/- 5.3%, Kt/V was 1.13 +/- 0.1, and beta-2 microglobulin reduction was 42.5 +/-4%. Incidence of hypotension and requirement of escalation of inotropes during SLED-f was 18.18%. Filter clotting occurred twice in one patient.

CONCLUSION

SLED-f is a safe and effective modality for use as a transition therapy between CKRT and intermittent hemodialysis in children in the PICU.

Long-term arteriovenous fistula prognosis for maintenance hemodialysis patients who accepted PIRRT by using arteriovenous fistula

BACKGROUND

Maintenance hemodialysis (MHD) patients are often admitted to the hospital for severe morbidities. Prolonged intermittent renal replacement therapy (PIRRT) is required during the hospital staying. There are controversial opinions on the use of arteriovenous fistula (AVF) as vascular access for PIRRT in MHD patients.

METHODS

Patients with AVF who accepted PIRRT in our center between January 2014 and June 2021 were retrospectively screened. AVF dysfunction and patient mortality were assessed as endpoints. Univariate and multivariate regression models were employed to identify the risk factors of AVF dysfunction.

RESULTS

About 162 patients were included in our present study. Twenty-six experienced AVF dysfunction, of whom 53.8%, 19.2%, and 27.0% had percutaneous transluminal balloon angioplasty, surgical revision, and AVF reconstruction, respectively. The accumulated AVF dysfunction rates were 11.8%, 16.2%, and 21.0% in 1, 2, and 3 years, respectively. Multivariate analysis revealed that smoking (HR 2.750, 95% CI 1.181-6.402, p = 0.019), higher platelet (PLT, HR 1.009, 95% CI 1.000-1.017, p = 0.047), higher prothrombin activity (PTA, HR 1.039, 95% CI 1.012-1.066, p = 0.004), and lower diastolic blood pressure (DBP, HR 0.963, 95% CI 0.932-0.996, p = 0.026) were independent risk factors for AVF dysfunction. During the follow-up period, 37 patients died.

CONCLUSIONS

Overall, the use of AVF for PIRRT might not dramatically increase the incidence of AVF dysfunction. And, Smoking, lower DBP, higher PLT, and higher PTA were associated with increased AVF dysfunction.

A therapeutic regimen of ceftazidime-avibactam for a critical patient receiving prolonged intermittent renal replacement therapy

The present report firstly described a critically ill patient receiving a dosing regimen of ceftazidime-avibactam (CAZ-AVI) (1.875g q24h) to eliminate multidrug-resistant Klebsiella pneumoniae and a scheduled time for prolonged intermittent renal replacement therapy (PIRRT) every 48h (6h-session beginning 12h after the previous dosage on hemodialysis day). This dosing regimen for CAZ-AVI and a scheduled time for PIRRT allowed pharmacodynamic parameters of ceftazidime and avibactam to have little difference on hemodialysis and non-hemodialysis days so that we can maintain a relatively stable drug concentration. Our report highlighted not only the importance of dosing regimens in patients with PIRRT but also the significance of hemodialysis time points during the dosing interval. The innovative therapeutic plan proved to be suitable for patients infected with Klebsiella pneumoniae when on PIRRT according to the trough plasma concentrations of ceftazidime and avibactam which were maintained above the minimum inhibitory concentration during the dosing interval.

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.

Acute Kidney Injury and Renal Replacement Therapy: A Review and Update for the Perioperative Physician

Post-operative acute kidney injury is a devastating complication with significant morbidity and mortality associated with it. The perioperative anesthesiologist is in a unique position to potentially mitigate the risk of postoperative AKI, however, understanding the pathophysiology, risk factors and preventative strategies is paramount. There are also certain clinical scenarios, where renal replacement therapy may be indicated intraoperatively including severe electrolyte abnormalities, metabolic acidosis and massive volume overload. A multidisciplinary approach including the nephrologist, critical care physician, surgeon and anesthesiologist is necessary to determine the optimal management of these critically ill patients.

Overview of the Medical Management of the Critically Ill Patient

The medical management of the critically ill patient focuses predominantly on treatment of the underlying condition (e g, sepsis or respiratory failure). However, in the past decade, the importance of initiating early prophylactic treatment for complications arising from care in the intensive care unit setting has become increasingly apparent. As survival from critical illness has improved, there is an increased prevalence of postintensive care syndrome-defined as a decline in physical, cognitive, or psychologic function among survivors of critical illness. The Intensive Care Unit Liberation Bundle, a major initiative of the Society of Critical Care Medicine, is centered on facilitating the return to normal function as early as possible, with the intent of minimizing iatrogenic harm during necessary critical care. These concepts are universally applicable to patients seen by nephrologists in the intensive care unit and may have particular relevance for patients with kidney failure either on dialysis or after kidney transplant. In this article, we will briefly summarize some known organ-based consequences associated with critical illness, review the components of the ABCDEF bundle (the conceptual framework for Intensive Care Unit Liberation), highlight the role nephrologists can play in implementing and complying with the ABCDEF bundle, and briefly discuss areas for additional research.

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.

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

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

Daily Hemodialysis Helps Critical Nephritic Lupus Patient: A Case Report

Background: Nephritic lupus is the most common and serious complication of systemic lupus erythematosus (SLE) and is associated with a worse prognosis. Hemodialysis is effective in alleviating symptoms and renal involvement in a nephritic lupus patient. Method: A 33-year-old female was diagnosed with SLE in September 2017. She was also diagnosed with diffuse membranous proliferative glomerulonephritis, as confirmed with a kidney biopsy. She complained of gradual onset limb weakness and peripheral edema 3 months before admission. She was treated with 6 cycles of cyclophosphamide and continued with methylprednisolone 16 mg once daily, hydroxychloroquine 200 mg once daily, and myfortic 360 mg twice daily. A day before ICU admission, her creatinine level was increased to 4.6 mg/dl with an estimated GFR of 12 ml/min and her symptoms then worsened into seizures and lung edema. Daily hemodialysis with heparin-free SLEDD was performed. About 2L was extracted for the first 6 hours with Qb 150 ml and Qd 300 ml and was continued until the day after. For the next 4 days, 3L was extracted per day with Qb 200ml and Qd 500 ml. The patients’ hemodynamic status was within normal limits during dialysis period. The condition improved and the patient was transferred to the ward. Discussions: Hemodialysis is a way to solve kidney problems in in nephritic lupus and SLE patients in general. It should not only be employed for mainly kidney problems but could be beneficial in autoimmune patients with conditions such as nephritic lupus. Slowly extracted dialysis type would be a good and inexpensive option to resolve nephritic lupus in compromising lupus patients. Filtration is ensured and solute removal is achieved relatively equivalent to CRRT. Conclusion: Daily hemodialysis could increase renal salvation by providing less creatinine serum and removing accumulated fluids. The SLEDD type could be used for critical nephritic lupus patients with reduced hemodynamic perturbations, minimal anticoagulant, and lower cost.

Refractoriness of Hyperkalemia and Hyperphosphatemia in Dialysis-Dependent AKI Associated with COVID-19

Background

Persistent hyperkalemia (hyperK) and hyperphosphatemia (hyperP) despite renal replacement therapy (RRT) was anecdotally reported in COVID-19 and acute kidney injury (AKI) requiring RRT (CoV-AKI-RRT). However, observation bias could have accounted for the reports. Thus, we systematically examined the rate and severity of hyperK and hyperP in patients with CoV-AKI-RRT in comparison with the pre-COVID-19 era.

Methods

We identified patients with CoV-AKI-RRT treated with sustained low-efficiency dialysis (SLED) for ≥2 days in March-April 2020. As pre-COVID-19 control, we included patients with AKI treated with SLED in December 2019. We examined the rates of hyperK (serum potassium [sK] ≥5.5 mEq/L), severe hyperK (sK ≥6.5 mEq/L), hyperP (serum phosphate [sP] ≥4.5 mg/dl), and moderate or severe hyperP (sP ≥7-10 and >10 mg/dl, respectively) as %SLED-days with an event.

Results

Along the duration of SLED, the incidence of hyperK was greater in CoV-AKI-RRT (n=64; mean 19%±2% versus 14%±3% SLED-days, P=0.002) compared with control (n=60). The proportion of patients with one or more event of severe hyperK was greater in CoV-AKI (33% versus 7%, P<0.001). The incidence of hyperP was similar between groups (mean 56%±4% versus 53%±5% SLED-days, P=0.49). However, the proportion of patients with one or more event of moderate and severe hyperP was greater in CoV-AKI-RRT (86% versus 60%, P=0.001, and 50% versus 18%, P<0.001, respectively). Among those with CoV-AKI-RRT, sK and sP correlated with lactate dehydrogenase (LDH; r=0.31, P=0.04, and r=0.31, P=0.04, respectively), whereas hyperP also correlated with shorter SLED runs (hours/run; r=-0.27, P=0.05).

Conclusions

Refractory hyperK and hyperP were more frequent in CoV-AKI-RRT compared with the pre-COVID-19 era. Because of the correlation of sK and sP with higher LDH and sP with shorter SLED runs, intracellular ion release from cell injury due to cytokine storm and RRT interruptions may account for the findings.

Renal replacement therapy for critically ill patients with COVID-19-associated acute kidney injury: A review of current knowledge

The outbreak of coronavirus disease 2019 (COVID-19) has rapidly evolved into a global pandemic. A significant proportion of COVID-19 patients develops severe symptoms, which may include acute respiratory distress syndrome and acute kidney injury as manifestations of multi-organ failure. Acute kidney injury (AKI) necessitating renal replacement therapy (RRT) is increasingly prevalent among critically ill patients with COVID-19. However, few studies have focused on AKI treated with RRT. Many questions are awaiting answers as regards AKI in the setting of COVID-19; whether patients with COVID-19 commonly develop AKI, what are the underlying pathophysiologic mechanisms? What is the best evidence regarding treatment approaches? Identification of the potential indications and the preferred modalities of RRT in this context, is based mainly on clinical experience. Here, we review the current approaches of RRT, required for management of critically ill patients with COVID-19 complicated by severe AKI as well as the precautions that should be adopted by health care providers in dealing with these cases. Electronic search was conducted in MEDLINE, PubMed, ISI Web of Science, and Scopus scientific databases. We searched the terms relevant to this review to identify the relevant studies. We also searched the conference proceedings and ClinicalTrials.gov database.

Choosing a CRRT machine and modality

Expanded use and steady improvements in continuous renal replacement techniques (CRRT) have enhanced the safety of the application of kidney replacement therapy (KRT) to hemodynamically unstable intensive care unit (ICU) patients. The longer duration of therapy and the personalized prescription provided by continuous therapies are associated with greater hemodynamic stability and a modestly higher likelihood of kidney recovery than standard intermittent hemodialysis (IHD). Studies designed to evaluate the effect on mortality over intermittent therapies lack evidence of benefit. A lack of standardization and considerable variation in how CRRT is performed leads to wide variation in how the technique is prescribed, delivered, and optimized. Technology has progressed in critical care nephrology, and more progress is coming. New CRRT machines are equipped with a friendly user interface that allows easy performance and monitoring, permitting outcome measurements and improved patient quality control. This review discusses the key concepts necessary to guide nephrologists to prescribe and deliver KRT to critically ill ICU patients.

Fosfomycin single- and multiple-dose pharmacokinetics in patients undergoing prolonged intermittent renal replacement therapy

BACKGROUND

Fosfomycin is used increasingly in the treatment of MDR bacteria. It is eliminated by renal excretion, but data regarding dosing recommendations for patients undergoing modern means of renal replacement therapies are scarce.

OBJECTIVES

Evaluation of the pharmacokinetics (PK) of fosfomycin in patients undergoing prolonged intermittent renal replacement therapy (PIRRT) to guide dosing recommendations.

METHODS

Fosfomycin was given in 11 (7 female) patients with severe infections undergoing PIRRT. Plasma levels were measured at several timepoints on the first day of fosfomycin therapy, as well as 5-6 days into therapy, before and after the dialyser, to calculate its clearance. Fosfomycin was measured in the collected spent dialysate.

RESULTS

The median (IQR) plasma dialyser clearance for fosfomycin was 183.4 (156.9-214.9) mL/min, eliminating a total amount of 8834 (4556-10 440) mg of fosfomycin, i.e. 73.9% (45.3%-93.5%) of the initial dose. During PIRRT, the fosfomycin half-life was 2.5 (2.2-3.4) h. Data from multiple-dose PK showed an increase in fosfomycin Cmax from 266.8 (166.3-438.1) to 926.1 (446.8-1168.0) mg/L and AUC0-14 from 2540.5 (1815.2-3644.3) to 6714 (4060.6-10612.6) mg·h/L. Dialysis intensity during the study was 1.5 L/h. T>MIC was 100% in all patients.

CONCLUSIONS

Patients undergoing PIRRT experience significant fosfomycin elimination, requiring a dose of 5 g/8 h to reach adequate plasma levels. However, drug accumulation may occur, depending on dialysis frequency and intensity.

Short-term prognosis and influencing factors of patients with acute kidney injury treated with prolonged intermittent renal replacement therapy

BACKGROUND

Studies assessing prognosis after prolonged intermittent renal replacement therapy (PIRRT) for acute kidney injury (AKI) are scarce.

AIM

To assess the impact of PIRRT on AKI and factors associated with short-term prognosis.

METHODS

In this retrospective nested case-control study, AKI patients administered PIRRT in Shanghai General Hospital from 01/2012 to 10/2018 were assigned to the 30-day survivor and death groups. Surviving patients were further divided into the kidney recovery and non-recovery groups at 30 and 90 days post-discharge, respectively. Propensity score matching was performed.

RESULTS

Totally 576 patients were included in the non-matched study population, mortality and kidney recovery rates were 51.7% and 33.4%, respectively. After propensity score matching, there were 250 patients in each of the death and survival groups. Low PIRRT frequency (OR = 2.165, 95% CI = 1.178-3.978), infection (OR = 0.447, 95% CI = 0.251-0.795), number of damaged vital organs (OR = 0.478, 95% CI = 0.346-0.661), sodium (OR = 0.958, 95% CI = 0.928-0.988), total protein (OR = 1.047, 95% CI = 1.022-1.072), pre-dialysis thrombin time (TT; OR = 0.959, 95% CI = 0.936-0.983), pre-discharge glomerular filtration rate (GFR; OR = 1.024, 95% CI = 1.017-1.031) and admission ward [reference: renal ward; intensive care unit (OR = 0.042, 95% CI = 0.008-0.211); surgery (OR = 0.092, 95% CI = 0.018-0.465); medical (OR = 0.049, 95% C% CI = 0.009-0.259); other (OR = 0.097, 95% CI = 0.016-0.572)] independently predicted 30-day mortality. Peripherally inserted central catheter (OR = 13.970, 95% CI = 1.439-135.589), urea nitrogen (OR = 0.961, 95% CI = 0.933-0.990) and pre-discharge GFR (OR = 1.102, 95% CI = 1.067-1.137) independently predicted 30-day kidney recovery. Pre-dialysis Scr (OR = 0.997, 95% CI = 0.995-0.999), urea nitrogen (OR = 0.948, 95% CI = 0.912-0.986) and pre-discharge GFR (OR = 1.137 95% CI = 1.088-1.189) independently predicted 90-day kidney recovery.

CONCLUSIONS

PIRRT improves survival and kidney function recovery in AKI patients. In patients with previous GFR ≥ 30 mL/(min-1.73 m² ) and no prior maintenance dialysis, PIRRT at 3-5 sessions/week might be appropriate.

Continuous renal replacement therapy and the COVID pandemic

Severe COVID‐19 illness and the consequent cytokine storm and vasodilatory shock commonly lead to ischemic acute kidney injury (AKI). The need for renal replacement therapies (RRTs) in those with the most severe forms of AKI is considerable and risks overwhelming health‐care systems at the peak of a surge. We detail the challenges and considerations involved in the preparation of a disaster response plan in situations such as the COVID‐19 pandemic, which dramatically increase demand for nephrology services. Taking careful inventory of all aspects of an RRT program (personnel, consumables, and machines) before a surge in RRT arises and developing disaster contingency protocol anticoagulation and for shared RRT models when absolutely necessary are paramount to a successful response to such a disaster.

Acute kidney injury in COVID 19 - an update on pathophysiology and management modalities

Acute kidney injury (AKI), characterised by fluid imbalance and overload, is prevalent in severe disease phenotypes of coronavirus disease 2019 (COVID-19). The elderly immunocompromised patients with pre-existing comorbidities being more risk-prone to severe COVID-19, the importance of early diagnosis and intervention in AKI is imperative. Histopathological examination of COVID-19 patients with AKI reveals viral invasion of the renal parenchyma and evidence of AKI. The definitive treatment for AKI includes renal replacement therapy and renal transplant. Immunosuppressant regimens and its interactions with COVID-19 have to be further explored to devise effective treatment strategies in COVID-19 transplant patients. Other supportive strategies for AKI patients include hemodynamic monitoring and maintenance of fluid balance. Antiviral drugs should be meticulously monitored in the management of these high-risk patients. We have focussed on the development of renal injury provoked by the SARS-CoV-2, the varying clinical characteristics, and employment of different management strategies, including renal replacement therapy, alongside the emerging cytokine lowering approaches.

Association between Prolonged Intermittent Renal Replacement Therapy and All-Cause Mortality in COVID-19 Patients Undergoing Invasive Mechanical Ventilation: A Retrospective Cohort Study

Background

The mortality rate of critically ill patients with coronavirus disease 2019 (COVID-19) was high. We aimed to assess the association between prolonged intermittent renal replacement therapy (PIRRT) and mortality in patients with COVID-19 undergoing invasive mechanical ventilation.

Methods

This retrospective cohort study included all COVID-19 patients receiving invasive mechanical ventilation between February 12 and March 2, 2020. All patients were followed until death or March 28, and all survivors were followed for at least 30 days.

Results

For 36 hospitalized COVID-19 patients receiving invasive mechanical ventilation, the mean age was 69.4 (±10.8) years, and 30 patients (83.3%) were men. Twenty-two (61.1%) patients received PIRRT (PIRRT group), and 14 cases (38.9%) were managed with conventional strategy (non-PIRRT group). There were no differences in age, sex, comorbidities, complications, treatments, and most of the laboratory findings. During the median follow-up period of 9.5 (interquartile range 4.3–33.5) days, 13 of 22 (59.1%) patients in the PIRRT group and 11 of 14 (78.6%) patients in the non-PIRRT group died. Kaplan-Meier analysis demonstrated prolonged survival in patients in the PIRRT group compared with that in the non-PIRRT group (p = 0.042). The association between PIRRT and a reduced risk of mortality remained significant in 3 different models, with adjusted hazard ratios varying from 0.332 to 0.398. Increased IL–2 receptor, TNF-α, procalcitonin, prothrombin time, and NT-proBNP levels were significantly associated with an increased risk of mortality in patients with PIRRT.

Conclusion

PIRRT may be beneficial for the treatment of COVID-19 patients with invasive mechanical ventilation. Further prospective multicenter studies with larger sample sizes are required.

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.

Bivalirudin dosing during prolonged intermittent renal replacement therapy: a case report

As patients transition between dialysis modalities, and from the intra- to the inter-dialytic period, medications with a narrow therapeutic index that are cleared in dialysis may require dose adjustments and close monitoring. Three cases of patients receiving bivalirudin while converting from continuous to prolonged intermittent renal replacement therapy are reported. Details provided include flow rates and ultrafiltrate volume. In these cases, it appears pre-emptive dose adjustments may be unwarranted, and clinicians should be aware of potential rebound after cessation of dialysis.

Management of Acute Kidney Injury in Coronavirus Disease 2019

Acute kidney injury is a common complication in hospitalized patients with coronavirus disease 2019. Similar to acute kidney injury associated with other conditions such as sepsis and cardiac surgery, morbidity and mortality are much higher in patients with coronavirus disease 2019 who develop acute kidney injury, especially in the intensive care unit. Management of coronavirus disease 2019-associated acute kidney injury with kidney replacement therapy should follow existing recommendations regarding modality, dose, and timing of initiation. However, patients with coronavirus disease 2019 are very hypercoagulable, and close vigilance to anticoagulation strategies is necessary to prevent circuit clotting. During situations of acute surge, where demand for kidney replacement therapy outweighs supplies, conservative measures have to be implemented to safely delay kidney replacement therapy. A collaborative effort and careful planning is needed to conserve dialysis supplies, to ensure that treatment can be safely delivered to every patient who will benefit for kidney replacement therapy.

Acute Kidney Injury in COVID-19 Pneumonia: A Single-Center Experience in Bahrain

Background Kidney disease accompanying coronavirus disease 2019 (COVID-19) is not well understood, and information about the presentation of acute kidney injury (AKI), its risk factors, and outcomes is scarce, particularly in Bahrain and the Gulf region. In this study, we aimed to determine the rate of AKI among patients hospitalized with COVID-19 pneumonia at a tertiary hospital in Bahrain and to describe the various aspects of AKI in these patients, including its relationship with respiratory failure and in-hospital mortality. Methods This retrospective observational cohort study of patients admitted with COVID-19 pneumonia from April 1 to May 31, 2020, excluded those aged less than 18 years, those with end-stage renal disease, and those with renal transplants. Clinical and laboratory patient data were collected. The Kidney Disease: Improving Global Outcomes (KDIGO) criteria were used to define AKI. Results The mean age across the 73 included patients was approximately 54 years; about 60% were men, and nearly 58% were Bahraini nationals. Of the patients, 39.7% (29) developed AKI during hospitalization, out of which 11.0% reached stage 1, 15.1% reached stage 2, and 13.7% reached stage 3. Of all patients, seven (9.6%) required hemodialysis. Chronic kidney disease conferred an increased risk for AKI (P = 0.003) as did critical COVID-19 status (P < 0.001) and the necessity for mechanical ventilation or intensive care admission (P < 0.001 for both). Additionally, AKI was significantly associated with a lower PaO2/FiO2 (partial pressure of arterial oxygen/percentage of inspired oxygen) ratio (P < 0.001) and a greater number of medications for COVID-19 pneumonia (P = 0.003). Finally, in-hospital death tolls were remarkably higher in patients with AKI (P < 0.001). No association was found between AKI and each of the following therapies: angiotensin-converting enzyme inhibitors or angiotensin receptor blockers, tocilizumab, and convalescent plasma. Conclusions The rate of AKI in patients hospitalized with COVID-19 pneumonia at our institution is relatively high and is strongly associated with disease severity, respiratory failure, and in-hospital mortality. Awareness of kidney disease in COVID-19 patients is crucial and of vital importance.

COVID-19 and the Kidneys: An Update

The new coronavirus disease 2019 (COVID-19) has become a world health emergency. The disease predominantly effects individuals between 30 and 79 years of age with 81% of cases being classified as mild. Despite the majority of the general population displaying symptoms similar to the common cold, COVID-19 has also induced alveolar damage resulting in progressive respiratory failure with fatalities noted in 6.4% of cases. Direct viral injury, uncontrolled inflammation, activation of coagulation, and complement cascades are thought to participate in disease pathogenesis. Patients with COVID-19 have displayed kidney damage through acute kidney injury, mild proteinuria, hematuria, or slight elevation in creatinine possibly as consequence of kidney tropism of the virus and multiorgan failure. The impact of COVID-19 on patients with pre-existing kidney impairment, including those with chronic kidney disease, kidney transplant recipients, and individuals on hemodialysis (HD) has not yet been clearly established. No specific treatments for COVID-19 have been found yet. Research has revealed several agents that may have potential efficacy against COVID-19, and many of these molecules have demonstrated preliminary efficacy against COVID-19 and are currently being tested in clinical trials.

COVID-19 and Renal Failure: Challenges in the Delivery of Renal Replacement Therapy

Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), first officially reported in December 2019 in Wuhan City, Hubei province, China, and has since lead to a pandemic. Most cases result in minor symptoms such as cough, fever, sore throat, myalgia, fatigue, nausea, diarrhea, loss of smell, and abdominal pain. As of April 8, 2020, more than 1,485,000 cases of COVID-19 have been reported in more than 200 countries and territories, resulting in over 90,000 deaths. Outcomes are worse in elderly patients, particularly males, and those with comorbidities, but can affect any age group. The incidence of acute kidney injury in patients with COVID-19 infection is about 3-15%; and in patients with severe infection requiring care in the intensive care unit, the rates of acute kidney injury increased significantly from 15% to 50%. Acute kidney injury is an independent risk factor for mortality in COVID-19 patients. The nephrologists, as well as intensivists, are facing immense daily challenges while providing care for these patients in the inpatient setting as well as end-stage renal disease patients on chronic dialysis in both inpatient and outpatient settings. In the current review article, we discussed the epidemiology and etiology of acute kidney injury, management of acute kidney injury including renal replacement therapy options (both hemodialysis and peritoneal dialysis) for inpatient floor, as well as intensive care unit settings. We also discussed the challenges faced by the outpatient dialysis units with COVID-19 infection. We discussed measures required to limit the spread of infection, as well as summarized the guidance as per the Centers for Disease Control and Prevention (CDC), American Society of Nephrology (ASN), American Society of Diagnostic and Interventional Nephrology (ASDIN) and the Vascular Access Society of the Americas (VASA).

Principles of Drug Dosing in Sustained Low Efficiency Dialysis (SLED) and Review of Antimicrobial Dosing Literature

The use of sustained low-efficiency dialysis (SLED) as a renal replacement modality has increased in critically ill patients with both acute kidney injury (AKI) and hemodynamic instability. Unfortunately, there is a paucity of data regarding the appropriate dosing of medications for patients undergoing SLED. Dose adjustment in SLED often requires interpretation of pharmacodynamics and pharmacokinetic factors and extrapolation based on dosing recommendations from other modes of renal replacement therapy (RRT). This review summarizes published trials of antimicrobial dose adjustment in SLED and discusses pharmacokinetic considerations specific to medication dosing in SLED. Preliminary recommendation is provided on selection of appropriate dosing for medications where published literature is unavailable.

Pediatric Continuous Renal Replacement Therapy (PCRRT) expert committee recommendation on prescribing prolonged intermittent renal replacement therapy (PIRRT) in critically ill children

INTRODUCTION

Recently, prolonged intermittent renal replacement therapies (PIRRT) have emerged as cost-effective alternatives to conventional CRRT and their use in the pediatric population has started to become more prominent. However, there is a lack of consensus guidelines on the use of PIRRT in pediatric patients in an intensive care setting.

METHODS

A literature search was performed on PubMed/Medline, Embase, and Google Scholar in conjunction with medical librarians from both India and the Cleveland Clinic hospital system to find relevant articles. The Pediatric Continuous Renal Replacement Therapy workgroup analyzed all articles for relevancy, proposed recommendations, and graded each recommendation for their strength of evidence.

RESULTS

Of the 60 studies eligible for review, the workgroup considered data from 37 studies to formulate guidelines for the use of PIRRT in children. The guidelines focused on the definition, indications, machines, and prescription of PIRRT.

CONCLUSION

Although the literature on the use of PIRRT in children is limited, the current studies give credence to their benefits and these expert recommendations are a valuable first step in the continued study of PIRRT in the pediatric population.

Renal Replacement Therapy in the ICU

OBJECTIVES

The incidence of acute kidney injury in critically ill patients is increasing steeply. Acute kidney injury in this setting is associated with high morbidity and mortality. There is no doubt that renal replacement therapy for the most severe forms of acute kidney injury can be life saving, but there are a number of uncertainties about the optimal application of renal replacement therapy for patients with acute kidney injury. The objective of this synthetic review is to present current evidence supporting best practices in renal replacement therapy for critically ill patients with acute kidney injury.

DATA SOURCES

We reviewed literature regarding timing of initiation of renal replacement therapy, optimal vascular access for renal replacement therapy in acute kidney injury, modality selection and dose or intensity of renal replacement therapy, and anticoagulation during renal replacement therapy, using the following databases: MEDLINE and PubMed. We also reviewed bibliographic citations of retrieved articles.

STUDY SELECTION

We reviewed only English language articles.

CONCLUSIONS

Current evidence sheds light on many areas of controversy regarding renal replacement therapy in acute kidney injury, providing a foundation for best practices. Nonetheless, important questions remain to be answered by ongoing and future investigation.

Drug Dosing Considerations in Critically Ill Patients Receiving Continuous Renal Replacement Therapy

Acute kidney injury is very common in critically ill patients requiring renal replacement therapy. Despite the advancement in medicine, the mortality rate from septic shock can be as high as 60%. This manuscript describes drug-dosing considerations and challenges for clinicians. For instance, drugs’ pharmacokinetic changes (e.g., decreased protein binding and increased volume of distribution) and drug property changes in critical illness affecting solute or drug clearance during renal replacement therapy. Moreover, different types of renal replacement therapy (intermittent hemodialysis, prolonged intermittent renal replacement therapy or sustained low-efficiency dialysis, and continuous renal replacement therapy) are discussed to describe how to optimize the drug administration strategies. With updated literature, pharmacodynamic targets and empirical dosing recommendations for commonly used antibiotics in critically ill patients receiving continuous renal replacement therapy are outlined. It is vital to utilize local epidemiology and resistance patterns to select appropriate antibiotics to optimize clinical outcomes. Therapeutic drug monitoring should be used, when possible. This review should be used as a guide to develop a patient-specific antibiotic therapy plan.

Waiting List and Kidney Transplant Vascular Risk: An Ongoing Unmet Concern

BACKGROUND

Chronic kidney disease (CKD) is an important independent risk factor for adverse cardiovascular events in patients waitlisted for kidney transplantation (KT). Although KT reduces cardiovascular risk, these patients still have a higher all-cause and cardiovascular mortality than the general population. This concerning situation is due to a high burden of traditional and nontraditional risk factors as well as uremia-related factors and transplant-specific factors, leading to 2 differentiated processes under the framework of CKD, atherosclerosis and arteriosclerosis. These can be initiated by insults to the vascular endothelial endothelium, leading to vascular calcification (VC) of the tunica media or the tunica intima, which may coexist. Several pathogenic mechanisms such as inflammation-related endothelial dysfunction, mineral metabolism disorders, activation of the renin-angiotensin system, reduction of nitric oxide, lipid disorders, and the fibroblast growth factor 23-klotho axis are involved in the pathogenesis of atherosclerosis and arteriosclerosis, including VC.

SUMMARY

This review focuses on the current understanding of atherosclerosis and arteriosclerosis, both in patients on the waiting list as well as in kidney transplant recipients, emphasizing the cardiovascular risk factors in both populations and the inflammation-related pathogenic mechanisms. Key Message: The importance of cardiovascular risk factors and the pathogenic mechanisms related to inflammation in patients waitlisted for KT and kidney transplant recipients.

A Pilot Study Evaluating the Effect of Cooler Dialysate Temperature on Hemodynamic Stability During Prolonged Intermittent Renal Replacement Therapy in Acute Kidney Injury

OBJECTIVES

Acute kidney injury requiring renal replacement therapy is associated with high morbidity and mortality. Complications of renal replacement therapy include hemodynamic instability with ensuing shortened treatments, inadequate ultrafiltration, and delay in renal recovery. Studies have shown that lowering dialysate temperature in patients with end-stage renal disease is associated with a decrease in the frequency of intradialytic hypotension. However, data regarding mitigation of hypotension by lowering dialysate temperature in patients with acute kidney injury are scarce. We conducted a prospective, randomized, cross-over pilot study to evaluate the effect of lower dialysate temperature on hemodynamic status of critically ill patients with acute kidney injury during prolonged intermittent renal replacement therapy.

DESIGN

Single-center prospective, randomized, cross-over study.

SETTING

ICUs and a step down unit in a tertiary referral center.

PATIENTS

Acute kidney injury patients undergoing prolonged intermittent renal replacement therapy.

INTERVENTIONS

Participants were randomized to start prolonged intermittent renal replacement therapy with dialysate temperature of 35°C or dialysate temperature of 37°C.

MEASUREMENTS AND MAIN RESULTS

The primary endpoint was the number of hypotensive events, as defined by any of the following: decrease in systolic blood pressure greater than or equal to 20 mm Hg, decrease in mean arterial pressure greater than or equal to 10 mm Hg, decrease in ultrafiltration, or increase in vasopressor requirements. The number of events was analyzed by Poisson regression and other outcomes with repeated-measures analysis of variance. Twenty-one patients underwent a total of 78 prolonged intermittent renal replacement therapy sessions, 39 in each arm. The number of hypotensive events was twice as high during treatments with dialysate temperature of 37°C, compared with treatments with the cooler dialysate (1.49 ± 1.12 vs 0.72 ± 0.69; incidence rate ratio, 2.06; p ≤ 0.0001). Treatment sessions with cooler dialysate were more likely to reach prescribed ultrafiltration targets.

CONCLUSIONS

Patients with acute kidney injury undergoing prolonged intermittent renal replacement therapy with cooler dialysate experienced significantly less hypotension during treatment. Prevention of hemodynamic instability during renal replacement therapy helped to achieve ultrafiltration goals and may help to prevent volume overload in critically ill patients.

Pharmacokinetics of flucloxacillin during prolonged intermittent renal replacement therapy in a 76-year-old man

Prolonged intermittent renal replacement therapy (PIRRT) use has been increasing in critically ill patients with kidney dysfunction. PIRRT can affect the pharmacokinetics of many drugs, although no data is available to guide flucloxacillin dosing in this clinical scenario. Herein, we describe the pharmacokinetics of flucloxacillin, given at 1 g every 4 h during PIRRT, in a 76-year-old, critically ill patient with a methicillin-susceptible Staphylococcus aureus (MSSA) prosthetic joint infection complicated by bacteraemia. Blood samples were taken over 2 days including during a 9-h PIRRT session. A two-compartment model was developed to describe differences in clearance of flucloxacillin during PIRRT and off-PIRRT (9.45 vs. 6.89 L/h). A flucloxacillin dose of 1 g every 4 h during PIRRT therapy appeared to attain adequate exposures for MSSA sepsis in this patient, however higher doses may be required for infection sites with poor drug penetration.

Single-best Choice Between Intermittent Versus Continuous Renal Replacement Therapy: A Review

Critically ill patients often develop multiorgan dysfunction syndrome. Acute kidney injury (AKI) is part of it. Renal replacement therapy (RRT) remains the primary choice of treatment in severely ill patients who develop AKI. Recent data have shown increased use of RRT in AKI patients. Therefore, the right choice of RRT plays an important role in the renal recovery of such patients. The question of which mode of RRT to apply has been the topic of study in the last two decades. Whether RRT should be conducted in intermittent mode, as intermittent hemodialysis (IHD), or in continuous mode, as continuous renal replacement therapy (CRRT), is still being investigated. CRRT has a hypothetical advantage when compared to IHD, as it involves a process in which there is gradual removal of fluids, better control of urea, better maintenance of the acid/base balance, and hemodynamic stability. However, IHD is more practical, cost-effective, does not require anticoagulation, decreases the bleeding risk, and removes the solute efficiently and rapidly in acute life-threatening conditions. Other modalities of RRT like sustained low-efficiency daily dialysis (SLEDD) and prolonged intermittent renal replacement therapy (PIRRT) have shown to encompass the benefits of both CRRT in terms of hemodynamic stability and IHD in terms of cost-efficiency. Although SLEDD is progressively being used as an alternative to CRRT and IHD, very few studies have shown to support it. In this article, we try to summarize the advantages and disadvantages of the different techniques used in RRT. With SLEDD gaining more popularity among the different modalities of RRT, we want to assess the possibility of its routine implementation as the single-best choice for RRT.

Antibiotic Dosing for Critically Ill Adult Patients Receiving Intermittent Hemodialysis, Prolonged Intermittent Renal Replacement Therapy, and Continuous Renal Replacement Therapy: An Update

Objective: To summarize current antibiotic dosing recommendations in critically ill patients receiving intermittent hemodialysis (IHD), prolonged intermittent renal replacement therapy (PIRRT), and continuous renal replacement therapy (CRRT), including considerations for individualizing therapy. Data Sources: A literature search of PubMed from January 2008 to May 2019 was performed to identify English-language literature in which dosing recommendations were proposed for antibiotics commonly used in critically ill patients receiving IHD, PIRRT, or CRRT. Study Selection and Data Extraction: All pertinent reviews, selected studies, and references were evaluated to ensure appropriateness for inclusion. Data Synthesis: Updated empirical dosing considerations are proposed for antibiotics in critically ill patients receiving IHD, PIRRT, and CRRT with recommendations for individualizing therapy. Relevance to Patient Care and Clinical Practice: This review defines principles for assessing renal function, identifies RRT system properties affecting drug clearance and drug properties affecting clearance during RRT, outlines pharmacokinetic and pharmacodynamic dosing considerations, reviews pertinent updates in the literature, develops updated empirical dosing recommendations, and highlights important factors for individualizing therapy in critically ill patients. Conclusions: Appropriate antimicrobial selection and dosing are vital to improve clinical outcomes. Dosing recommendations should be applied cautiously with efforts to consider local epidemiology and resistance patterns, antibiotic dosing and infusion strategies, renal replacement modalities, patient-specific considerations, severity of illness, residual renal function, comorbidities, and patient response to therapy. Recommendations provided herein are intended to serve as a guide in developing and revising therapy plans individualized to meet a patient's needs.

Acute kidney injury management using intermittent low efficiency haemodiafiltration in a critical care unit: 39 dogs (2012-2015)

BACKGROUND

Veterinary studies describing acute kidney injury (AKI) management using renal replacement therapy (RRT) are limited and have primarily focused on intermittent haemodialysis in North American populations. European data are lacking, although differences in populations, pathogen and toxin exposure and RRT modalities may exist between Europe and North America. The present study reviewed RRT-managed cases from the intensive care unit (ICU) of VetAgro Sup, Lyon, France, for the period 2012-2015. The aims were to describe a 4-h RRT protocol of intermittent low efficiency haemodiafiltration, population characteristics and outcomes in canine AKI cases requiring RRT and to identify prognostic variables. We defined DeltaCreat/h as the difference between the serum creatinine level after RRT treatment N and that before treatment N + 1 divided by the time between treatments (in hours).

RESULTS

Thirty-nine dogs were included, and 67% were males. The median (range) age, weight, hospitalization length and number of RRT treatments were 4.4 (0.25-15) years, 26.6 (6.7-69) kg, 8 (1-23) days and 3 (1-8) treatments, respectively. The main AKI causes were leptospirosis (74.4%) and nephrotoxins (15.4%). Age (4.0 vs 5.4 years; P = 0.04), admission urine output (0.5 mL/kg/h vs 0 mL/kg/h; P = 0.02) and hospitalization length (10 vs 4 days; P < 0.001) differed between survivors and non-survivors. Hospitalization length [odds ratio (OR) = 0.4], number of treatments (OR = 5.1), serum potassium level on day 2 (OR = 1.9), DeltaCreat/h between the first and second treatments (OR = 1.2), and UOP during hospitalization (OR = 0.2) were correlated with outcome. The main causes of death were euthanasia (44%) and haemorrhagic diatheses (33%). The overall survival rate was 54%, with 55% of survivors discharged with a median creatinine < 240 µmol/L.

CONCLUSIONS

This is the first description in the veterinary literature of a 4-h protocol of intermittent low efficiency haemodiafiltration to provide RRT in a veterinary critical care unit. While this protocol appears promising, the clinical application of this protocol requires further investigation. Among parameters associated with survival, UOP and DeltaCreat/h between the first and second RRT treatments may be prognostic indicators. The applicability of these parameters to other populations is unknown, and further international, multicentre prospective studies are warranted to confirm these preliminary observations.

Timing of renal replacement therapy initiation for acute kidney injury

BACKGROUND

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

OBJECTIVES

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

SEARCH METHODS

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

SELECTION CRITERIA

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

DATA COLLECTION AND ANALYSIS

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

MAIN RESULTS

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

AUTHORS' CONCLUSIONS

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

Antibiotic Dosing in Sustained Low-Efficiency Dialysis in Critically Ill Patients

Purpose of review

Sustained low-efficiency dialysis (SLED) is increasingly used as a renal replacement modality in critically ill patients with acute kidney injury (AKI) and hemodynamic instability. There is, therefore, a greater need for the understanding of the antibiotic dosage and pharmacokinetics in these patients, to provide them with optimal therapy.

Sources of information

PubMed/Medline, Embase, and Google Scholar.

Methods

PubMed/Medline, Embase, and Google Scholar databases were searched using a combination of key words: dialysis, end stage renal disease, renal failure, sustained low efficiency dialysis, extended daily dialysis, prolonged intermittent renal replacement therapy (PIRRT), and antibiotic dosing. Studies that investigated antibiotic dosing and pharmacokinetics during SLED/extended daily dialysis/PIRRT were selected for this review.

Key findings

Eleven studies met inclusion criteria and selected for data extraction. The data with regard to dialysis specifications, type of antibiotic including dosages, drug clearances, and dosage recommendations are summarized in Table 1. It is a challenge to find therapeutic doses for antibiotics during SLED therapy because, in general, only aminoglycosides and vancomycin can be assayed in clinical laboratories.

Limitations

Although current studies on antibiotic dosing in SLED are limited due to diverse and undersized patient populations, antibiotic dosage adjustments for patients receiving SLED discussed here will serve as a valuable guide. Future large-scale research should focus on establishing guidelines for antibiotic dosage in SLED.

Implications

Pharmacokinetic principles should be taken into consideration for the appropriate dosing of drugs during SLED, yet it is vital to monitor response to drug to make sure therapeutic goals are achieved. Antibiotic dosing and timing relative to the initiation of SLED may be important to maximize either the time above the minimum inhibitory concentration (MIC) (time-dependent) or the peak to MIC ratio (concentration-dependent), balancing efficacy and toxicity concerns. Critical care physicians should liaise with nephrologists to make decisions regarding appropriate antibiotic dosing in patients undergoing SLED.

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.