The lower limit of intensity to control uremia during continuous renal replacement therapy

Intensive care unit continuous kidney replacement therapy: time to change dosage recommendations?

Continuous kidney replacement therapy (CKRT) is the predominant form of acute kidney support used for hemodynamically unstable adult ICU patients with severe AKI (KDIGO stage 3). The success of CKRT depends on the achieved doses. Practice patterns worldwide are highly variable. A contemporary understanding of treatment adequacy is essential. The KDIGO AKI clinical guidelines recommend delivering effluent volumes of 20-25 ml/kg/hour for CKRT in the ICU setting, with the caveat that higher prescribed doses (25-30 ml(kg/h) may be necessary to achieve adequate delivered CKRT doses. The reference landmark trials provide definitive evidence that increases of delivered CKRT doses beyond the recommended dose are not beneficial for unselected ICU patients with severe AKI. However, the minimum delivered CKRT intensity at which underdosing becomes harmful remains unknown. The answer to this question has clinical relevance (dosing of critically ill patients with obesity or Covid-19 disease, minimizing adverse effects of CKRT) and a relevant impact on the costs of CKRT. The delivered dose of CKRT for Japanese ICU patients with severe AKI has been generally smaller (median 15 ml/h/kg) than the recommended delivered KDIGO dose. The most recently published retrospective cohort study by Okamoto et al. demonstrated that low delivered CKRT doses were associated with a higher mortality among critically ill patients with severe AKI. These data challenge the nation-wide accepted hypothesis that a lower limit of delivered CKRT (< 20 ml/ kg/h) may adequately control uremia/volume overload. Thus, there is an unmet clinical need for prospective randomized trials defining the minimal effective dose of CKRT. Given the dynamic nature of the precipitating critical illness and the natural course of most episodes of AKI, CKRT dose targets are likely to vary. Doses should be tailored to the needs of the individual patient within the limits of the KDIGO guideline recommendations. The Japanese experience with low-dose CKRT is not practice changing.

The Effects of Early-Phase, Low- or Standard-Intensity Continuous Renal Replacement Therapy on Acid-Base Control and Clinical Outcomes: An Observational Study

INTRODUCTION

The Kidney Disease Improving Global Outcomes (KDIGO) clinical practice guideline recommends administering an effluent volume of 20-25 mL/kg/h during continuous renal replacement therapy (CRRT) for acute kidney injury. Recent evidence on CRRT initiation showed that less intervention might be beneficial for renal recovery. This study aimed to explore the association between early-phase low CRRT intensity and acid-base balance corrections and clinical outcomes.

METHODS

This was a single-centre, retrospective, observational study at a tertiary intensive care unit (ICU) in Japan. All adult patients requiring CRRT in the ICU were included. Eligible patients were classified into the Low group (dialysate flow rate [QD] 10.0-19.9 mL/kg/h) and the Standard group (QD ≥20 mL/kg/h) by the intensity of CRRT at the beginning. The primary outcomes were acid-base parameters 6 h after CRRT initiation. We used an inverse probability of treatment weighting analysis to estimate the association between the intensity group and the outcomes.

RESULTS

Overall, 194 patients were classified into the Low group (n = 144) and the Standard group (n = 50). The Standard group presented with more severe acid-base disturbances, including lower pH and base excess (BE) at baseline. At 6 h after CRRT initiation, pH, BE, and strong ion difference values were comparable, even after adjusting for baseline severity. Despite the efficient correction, no evident differences were observed in clinical outcomes between the two groups.

CONCLUSIONS

The initial standard intensity appeared to be efficient in correcting acid-base imbalance at the early phase of CRRT; however, further studies are needed to assess the impact on clinical outcomes.

Meta-analysis of haematocrit and activated partial thromboplastin time as risk factors for unplanned interruptions in patients undergoing continuous renal replacement therapy

OBJECTIVE

Although continuous renal replacement therapy (CRRT) is common, unplanned interruptions often limit its usefulness. Unplanned interruption refers to the forced interruption of blood purification treatment, the failure to complete blood purification treatment goals or the failure to meet blood purification schedule times. This study aimed to evaluate the effect of haematocrit and activated partial thromboplastin time (APTT) on the incidence of unplanned interruptions in critical patients with CRRT.

METHODS

A systematic review and a meta-analysis were performed by searching the databases of China National Knowledge Infrastructure, Wanfang, VIP, China Biomedical Literature, Cochrane Library, PubMed, Web of Science and Embase from their inception to 31st March 2022 for all studies with a comparator or independent variable relating to the unplanned interruption of CRRT.

RESULTS

Nine studies involving 1165 participants were included. Haematocrit and APTT were independent risk factors for the unplanned interruption of CRRT. The higher the haematocrit level, the greater the risk of unplanned CRRT interruptions (relative risk ratio [RR] = 1.04, 95% confidence interval [CI]: 1.02, 1.07, Z = 4.27, p < 0.001). The prolongation of APPT reduced the risk of unplanned CRRT interruptions (RR = 0.94, 95% CI: 0.92, 0.96, Z = 6.10, p < 0.001).

CONCLUSION

Haematocrit and APTT are the influencing factors on the incidence of unplanned interruptions in critical patients undergoing CRRT.

Combination of Multiple Hemodialysis Modes: Better Treatment Options for Patients Under Maintenance Hemodialysis

Purpose

Chronic renal failure has become a major public health concern and treatment strategies are urgently needed. We aimed to investigate whether combination of hemodialysis modes was superior to regular hemodialysis for patients under maintenance hemodialysis.

Patients and Methods

A total of 144 patients with end-stage renal failure (ESRF) were enrolled in this single-center retrospective study. Patients received regular hemodialysis (HD) were included in HD group (n=52), patients received regular HD plus hemodiafiltration (HDF) in HD/HDF group (n=47), patients received the combination of regular HD, HDF and hemoperfusion (HP) in HD/HDF/HP group (n=45). After 1-month and 24-months treatment, therapeutic effects were assessed in terms of nutritional status, control of complications, dialysis adequacy, mean arterial pressure (MAP), infection rate and living quality.

Results

When patients received 1-month treatment, there were no statistically significant differences among three groups. After 24-months treatment, patients in HD/HDF and HD/HDF/HP group presented with better dialysis adequacy, lower MAP and infection rate, higher serum albumin, hemoglobin and calcium levels, lower serum phosphorus and intact parathyroid hormone levels, lower incidence of malnutrition and the Hamilton Depression Scale score, higher the Barthel Index score than HD group (P<0.05). The levels of calcium, phosphorus and intact parathyroid hormone in HD/HDF/HP group were lower than those in HD/HDF group (P<0.05).

Conclusion

Our finding highly indicated that combination of hemodialysis modes was superior to regular HD for patients with ESRF in nutritional status, control of complications, dialysis adequacy, and living quality.

Ensuring Sustainability of Continuous Kidney Replacement Therapy in the Face of Extraordinary Demand: Lessons From the COVID-19 Pandemic

With the exponential surge in patients with coronavirus disease 2019 (COVID-19) worldwide, the resources needed to provide continuous kidney replacement therapy (CKRT) for patients with acute kidney injury or kidney failure may be threatened. This article summarizes subsisting strategies that can be implemented immediately. Pre-emptive weekly multicenter projections of CKRT demand based on evolving COVID-19 epidemiology and routine workload should be made. Corresponding consumables should be quantified and acquired, with diversification of sources from multiple vendors. Supply procurement should be stepped up accordingly so that a several-week stock is amassed, with administrative oversight to prevent disproportionate hoarding by institutions. Consumption of CKRT resources can be made more efficient by optimizing circuit anticoagulation to preserve filters, extending use of each vascular access, lowering blood flows to reduce citrate consumption, moderating the CKRT intensity to conserve fluids, or running accelerated KRT at higher clearance to treat more patients per machine. If logistically feasible, earlier transition to intermittent hemodialysis with online-generated dialysate, or urgent peritoneal dialysis in selected patients, may help reduce CKRT dependency. These measures, coupled to multicenter collaboration and a corresponding increase in trained medical and nursing staffing levels, may avoid downstream rationing of care and save lives during the peak of the pandemic.

RRT Selection for AKI Patients With Critical Illness

Acute kidney injury (AKI) is a critical burden on intensive care units in Asia. Renal replacement therapy (RRT) acts as strong supportive care for severe AKI. However, various RRT modalities are used in Asia because of the diversity in ethics, climate, geographic features, and socioeconomic status. Extracorporeal blood purification is used commonly in Asian intensive care units; however, intermittent RRT is preferred in developing countries because of cost and infrastructure issues. Conversely, continuous RRT is preferred in developed countries, indicating the predominance of hospital-acquired AKI patients with complications of hemodynamic instability. Peritoneal dialysis is delivered less frequently, although several studies have suggested promising results for peritoneal dialysis in AKI treatment. Of note, not all RRT modalities are available as a standard procedure in some Asian regions, and it is absolutely necessary to develop a sustainable infrastructure that can deliver optimal care for all AKI patients.

Effect of blood purification on serum miR-126 and VEGF levels in the process of atherosclerosis in uremic patients under maintenance hemodialysis

This study aims to study the influence of different blood purification approaches on the expression of miR-126 and VEGF serum levels in the development of atherosclerosis in uremic patients under maintenance hemodialysis (MHD). A total of 207 MHD patients with uremia were divided into HD (hemodialysis, n = 60), HDF (hemodiafiltration, n = 72), and HD + HP (hemodialysis + hemoperfusion, n = 75) groups based on different purification approaches. Eighty individuals who underwent physical examinations during the same period constituted the healthy controls. The serum levels of miR-126 and VEGF were examined by qRT-PCR and ELISA both before and after treatment, and the intima media thickness (IMT) value and plaque area were evaluated by color Doppler ultrasound. The serum miR-126 level was down-regulated in MHD patients compared with healthy controls, and this was negatively linked to VEGF. The post-treatment expression level of serum miR-126 in the HDF and HD + HP groups was remarkably increased, but VEGF was decreased in MHD patients, and especially significantly in the HDF group. In addition, IMT and plaque area were obviously improved in the HD group after treatment. Pearson correlation analysis showed a negative correlation of miR-126 with IMT and plaque area, but a positive association between VEGF and IMT and plaque area. miR-126 and VEGF are expected to become a valuable biomarker for monitoring the progression of atherosclerosis in uremic patients undergoing MHD.

Intensive Versus Minimal Standard Dosage for Peritoneal Dialysis in Acute Kidney Injury: A Randomized Pilot Study

BACKGROUND

Dosage for peritoneal dialysis (PD) in acute kidney injury (AKI) is controversial. This study aims to find benefits and risks of intensive versus minimal standard dosage of PD in AKI.

METHODS

In a tertiary-hospital, 93 AKI patients who required PD between May 2015 and January 2016 were enrolled in a randomized, open-label controlled study. Patients were randomized to intensive group (> 30 L) and minimal standard group (< 20 L) of PD volume per day for the first 2 consecutive days. The primary outcome was in-hospital mortality. The secondary outcomes were peritonitis rate, dialysis dependence, and PD leakage.

RESULTS

Seventy-five patients were analyzed (intensive PD n = 39; minimal standard PD n = 36). Mean age was 60 years. Most patients were in critical care (72% unstable hemodynamic, mean APACHE II score 26.2). Kt/V delivery per session was 0.61 and 0.38 in intensive and minimal standard PD dosage for the first 2 consecutive sessions. According to intention-to-treat analysis, the in-hospital mortality rate of intensive PD dosage was not significantly different from the minimal standard PD dosage (79% vs 63%, relative risk [RR] 1.11, 95% confidence interval [CI] 0.80 to 1.51, p = 0.13). The dialysis dependence rate and PD leakage were not significantly different between the 2 groups. The rate of PD peritonitis was slightly higher in the intensive PD dosage group (15.3% vs 8.3%, p = 0.34).

CONCLUSION

Among AKI patients who required PD, there was no significant difference in in-hospital mortality between intensive and minimal standard PD dosage.

Evaluation of CRRT effects on pyemic secondary AKI by serum cartilage glycoprotein 39 and Annexin A1

The aim of the present study was to examine the effects of continuous renal replacement therapy (CRRT) on pyemic secondary acute kidney injury (AKI) by serum cartilage glycoprotein 39 (YKL-40) and Annexin A1. From October, 2013 to October, 2015, 45 pyemic secondary AKI cases and 40 pyemic non-secondary AKI cases were selected for the present study. There were also 35 cases of physical examination volunteers. The serum YKL-40 and Annexin A1 levels were compared. CRRT was applied to pyemic secondary AKI patients and based on the obtained results the patients were divided into the success and failure groups. YKL-40, Annexin A1, hs-CRP, creatinine and urea nitrogen levels after 1, 6, 12, 24, 48 and 72 h of AKI were measured. The YKL-40 and Annexin A1 levels in the pyemic secondary AKI group were significantly higher than those in other two groups and differences were statistically significant (P<0.05). There was no statistically significant difference regarding time period for applying CRRT in the success and failure groups (P>0.05). The peak level of YKL-40 and Annexin A1 in the success group decreased more rapidly compared to the failure group and the difference was statistically significant (P<0.05). When the differences in creatinine and urea nitrogen levels at different time points were compared between the success and failure groups, no statistical significance was observed (P>0.05). However, the success group showed a significantly lower level compared to the failure group at 72 h. Comparisons for other time periods showed no statistical significance (P>0.05). Thus, the serum cartilage glycoprotein 39 and Annexin A1 level were able to predict the clinical effects of CRRT on pyemic secondary AKI.