Prescription of CRRT: a pathway to optimize therapy

CRRT influences PICCO measurements in febrile critically ill patients

The aim of this study was to investigate whether continuous renal replacement therapy (CRRT) influences the global end-diastolic volume index (GEDVI), cardiac index (CI), and extravascular lung water index (EVLWI) measured by Pulse Index Continuous Cardiac Output (PICCO) in febrile patients. Fifteen fever patients were included in this study. CI, GEDVI, EVLWI, heart rate (HR), and mean arterial pressure (MAP) were measured at five time-points: before CRRT (T0), immediately after CRRT started (T1), 15 min after CRRT started (T2), immediately after CRRT stopped (T3), and 15 min after CRRT stopped (T4). Results have shown that CI and GEDVI were decreased significantly in T1 (CI: 4.09 ± 0.72 vs 2.81 ± 0.58 L/min m², P = 0.000 and GEDVI: 727.86 ± 63.47 vs 531.07 ± 66.63 mL/m², P = 0.000). However, CI and GEDVI were significantly increased in T3 (CI: 4.09 ± 0.72 vs 7.23 ± 1.32 L/min m², P = 0.000 and GEDVI 727.86 ± 63.47 vs 1339.17 ± 121.52 mL/m², P = 0.000). There were no significant differences in T2 and T4. Among the five-time points, no measurement errors were observed with regards to HR, MAP, and EVLWI. Therefore, the data herein contained suggests that PICCO measurements should begin 15 min after the start or stop of CRRT.

Comparison of the Treatment Efficacy of Continuous Renal Replacement Therapy and Intermittent Hemodialysis in Patients With Acute Kidney İnjury Admitted to the Intensive Care Unit

Introduction and aim

Acute kidney injury (AKI) is part of the multiple organ dysfunction syndrome in critically ill patients and is a common condition in intensive care units (ICUs). Renal replacement therapy (RRT) is the cornerstone of treatment for AKI in critically ill patients. This patient population has a high mortality rate despite RRT. There are two methods of RRT for patients in ICUs: intermittent hemodialysis (IHD) and continuous renal replacement therapy (CRRT). Both CRRT and IHD similarly provide adequate metabolic control. We aimed to compare these two RRT modalities in terms of ICU stay, mortality, and laboratory recovery in these patients with high mortality.

Materials and methods

A total of 120 patients with AKI who needed RRT in the ICU were included in the study (CRRT, n:40; IHD, n:80). Acute Physiology and Chronic Health Evaluation (APACHE) II, Sepsis-related Organ Failure Assessment (SOFA), and Simplified Acute Physiology Score (SAPS)-II scores at the time of admission to the ICU were calculated. Mean arterial pressure, urea, creatinine, sodium, potassium, calcium, pH, lactate, and bicarbonate levels were measured before and after dialysis. Patients were classified as living and deceased. Factors affecting the length of stay in the intensive care unit and 30-day mortality were evaluated. The variability in laboratory parameters between groups before and after dialysis was examined. The groups were compared with these parameters.

Results

Sixty-one point seven percent (61.7%, n:74) of the patients were female. The mean age was 62.90±13.64 years. At the time of admission to the ICU, the patients' SAPS II score was 45.05±12.76, APACHE II score was 22.05±6.32, and SOFA score was 8.26±2.48. 66.7% (n:80) of the patients included in the study died, and the length of stay of these patients in the ICU was 12.85±10.23 days. When the groups were compared, SAPS II, APACHE II scores, and SOFA scores were significantly higher in the CRRT group than in the IHD group (p:0.038, p:0.015, p:0.027, respectively). Although the length of stay in the ICU was shorter in the CRRT group, it was not statistically significant (p:0.075). There was no statistically significant difference between the groups in terms of mortality (p: 0.891). SAPS-II, APACHE II, and SOFA score affected 30-day mortality while age, gender, and RRT modalities were not associated with mortality. The improvement in laboratory parameters between the pre and post-RRT groups was statistically more significant in the IHD group (p<0.001). It was determined that there was a statistically greater decrease in mean arterial pressure in the IHD group (p<0.001).

Conclusions

It was determined that there was no difference between the CRRT and IHD modalities applied in patients with AKI admitted to the ICU in terms of mortality and length of stay in the ICU. It was observed that both modalities improved on laboratory parameters, but the improvement was greater in the IHD group. However, it was determined that there was a statistically greater decrease in mean arterial pressure in the IHD group.

Current Practice of Fluid Maintenance and Replacement Therapy in Mechanically Ventilated Critically Ill Children: A European Survey

Appropriate fluid management in mechanically ventilated critically ill children remains an important challenge and topic of active discussion in pediatric intensive care medicine. An increasing number of studies show an association between a positive fluid balance or fluid overload and adverse outcomes. However, to date, no international consensus regarding fluid management or removal strategies exists. The aim of this study was to obtain more insight into the current clinical practice of fluid therapy in mechanically ventilated critically ill children. On behalf of the section of cardiovascular dynamics of the European Society of Pediatric and Neonatal Intensive Care (ESPNIC) we conducted an anonymous survey among pediatric intensive care unit (PICU) specialists in Europe regarding fluid overload and management. A total of 107 study participants responded to the survey. The vast majority of respondents considers fluid overload to be a common phenomenon in mechanically ventilated children and believes this complication is associated with adverse outcomes, such as mortality and duration of respiratory support. Yet, only 75% of the respondents administers a lower volume of fluids (reduction of 20% of normal intake) to mechanically ventilated critically ill children on admission. During PICU stay, a cumulative fluid balance of more than 5% is considered to be an indication to reduce fluid intake and start diuretic treatment in most respondents. Next to fluid balance calculation, the occurrence of peripheral and/or pulmonary edema (as assessed including by chest radiograph and lung ultrasound) was considered an important clinical sign of fluid overload entailing further therapeutic action. In conclusion, fluid overload in mechanically ventilated critically ill children is considered an important problem among PICU specialists, but there is great heterogeneity in the current clinical practice to avoid this complication. We identify a great need for further prospective and randomized investigation of the effects of (restrictive) fluid strategies in the PICU.

Comparison of CVVH and CVVHDF on filter lifespan and solute removal - a randomized controlled trial

INTRODUCTION

This study aimed to investigate whether Continuous Veno-Venous Hemodiafiltration (CVVHDF) has a different filter lifespan and molecular solutes clearance when compared to Continuous Veno-Venous Hemofiltration (CVVH).

METHODS

Sixty patients were enrolled in this study and randomly assigned to the CVVHDF (n=30) or CVVH (n=30) groups. Demographics, laboratory tests, urea, creatinine, IL-6, β2-microglobulin, and myoglobulin clearance were recorded.

RESULTS

Patients in the CVVH group had a shorter median time of filter lifespan compared with those in the CVVHDF group (20 vs 37.5 hours, p = 0.002). Urea and creatinine clearance were not significantly different between groups over time (p >0.05). IL-6, β2-microglobulin, and myoglobulin clearance were higher in the CVVH group. The transmembrane pressure (TMP) was significantly higher in the CVVH group.

CONCLUSION

The use of CVVHDF may lead to a longer filter lifespan and lower clearance of medium and large molecules without affecting the small molecular solute clearance.

Regional Hypertonic Citrate Anticoagulation in Membrane Therapeutic Plasma Exchange: A Case Series

Rationale:

Protocols for regional citrate anticoagulation with the hypertonic 4% trisodium citrate solution have been recently described as an anticoagulation strategy during membrane therapeutic plasma exchange (mTPE). The effect of citrate in the patient’s systemic hemostasis is negligible, thus regional citrate anticoagulation application is advantageous in circumstances in which heparin-based protocols are deemed unsafe for patients with a high risk of bleeding. The downsides of using hypertonic citrate solutions are mainly hypocalcemia and hypernatremia that ultimately can cause adverse clinical events.

Presenting concerns of the patient:

(1) A 57-year-old Caucasian female with a history of active vaginal bleeding secondary to endometrial hyperplasia. She had a history of antiphospholipid syndrome, and systemic lupus erythematosus with marked refractory autoimmune thrombocytopenia. Her platelet count was persistently below 4,000/mm³ even after different immunosuppressive regimens and daily platelet transfusions. (1) A 70-year-old Caucasian female was hospitalized presenting acute kidney injury stage 3 due to rapidly progressive antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis, however without the need for renal replacement therapy. At admission, serum creatinine (sCr) was 3.56 mg/dL (normal range: 0.53-1.00 mg/dL). Her baseline sCr was 0.8 mg/dL obtained 6 months earlier. Chest tomography revealed bilateral masses compatible with granulomatous lesions and no signs of alveolar bleeding. Since severe cases of ANCA vasculitis involving the lungs may evolve with alveolar hemorrhage, heparin was avoided.

Diagnoses:

(1) Systemic lupus erythematosus-associated autoimmune thrombocytopenia and (2) ANCA-associated vasculitis with kidney and lung involvement.

Interventions:

Herein, we describe a case series of 12 consecutive mTPE treatments in 2 different patients using regional 4% trisodium citrate anticoagulation.

Outcomes:

All the sessions were uneventful, presented only minor electrolyte imbalances, and were effectively completed without early interruptions due to clotting of the plasmafilter.

Teaching points:

In our 2 cases, extracorporeal regional citrate anticoagulation was successful in optimizing plasmafilter patency without bleeding events in 2 high-risk patients using established protocols for the citrate and calcium infusions.

Sodium-based osmotherapy for hyponatremia in acute decompensated heart failure

Acute decompensated heart failure (ADHF) accounts for more than 1 million hospital admissions annually and is associated with high morbidity and mortality. Decongestion with removal of increased total body sodium and total body water are goals of treatment. Acute kidney injury (AKI) or chronic kidney disease (CKD) is present in two-thirds of patients with ADHF. The pathophysiology of ADHF and AKI is bidirectional and synergistic. AKI and CKD complicate the management of ADHF by decreasing diuretic efficiency and excretion of sodium and water. Among patients hospitalized with ADHF, hyponatremia is the most common electrolyte abnormality and is classically encountered with volume overload. ADHF represents an additional therapeutic challenge particularly when oligoanuria is present. Predilution continuous venovenous hemofiltration with sodium-based osmotherapy can safely increase plasma sodium concentration without deleteriously increasing total body sodium. We present a detailed methodology that addresses the issue of hypervolemic hyponatremia in patients with ADHF and AKI.

Development and Validation of a Simple-to-Use Nomogram for Predicting In-Hospital Mortality in Patients With Acute Heart Failure Undergoing Continuous Renal Replacement Therapy

Background: Patients with acute heart failure (AHF) who require continuous renal replacement therapy (CRRT) have a high risk of in-hospital mortality. It is clinically important to screen high-risk patients using a model or scoring system. This study aimed to develop and validate a simple-to-use nomogram consisting of independent prognostic variables for the prediction of in-hospital mortality in patients with AHF undergoing CRRT. Methods: We collected clinical data for 121 patients with a diagnosis of AHF who underwent CRRT in an AHF unit between September 2011 and August 2020 and from 105 patients in the medical information mart for intensive care III (MIMIC-III) database. The nomogram model was created using a visual processing logistic regression model and verified using the standard method. Results: Patient age, days after admission, lactic acid level, blood glucose concentration, and diastolic blood pressure were the significant prognostic factors in the logistic regression analyses and were included in our model (named D-GLAD) as predictors. The resulting model containing the above-mentioned five factors had good discrimination ability in both the training group (C-index, 0.829) and the validation group (C-index, 0.740). The calibration and clinical effectiveness showed the nomogram to be accurate for the prediction of in-hospital mortality in both the training and validation cohort when compared with other models. The in-hospital mortality rates in the low-risk, moderate-risk, and high-risk groups were 14.46, 40.74, and 71.91%, respectively. Conclusion: The nomogram allowed the optimal prediction of in-hospital mortality in adults with AHF undergoing CRRT. Using this simple-to-use model, the in-hospital mortality risk can be determined for an individual patient and could be useful for the early identification of high-risk patients. An online version of the D-GLAD model can be accessed at https://ahfcrrt-d-glad.shinyapps.io/DynNomapp/. Clinical Trial Registration: www.ClinicalTrials.gov, identifier: NCT0751838.

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.

A Quality Improvement Initiative to Reduce the Frequency of Delays in Initiation and Restarts of Continuous Renal Replacement Therapy

BACKGROUND

Continuous renal replacement therapy (CRRT) is a lifesaving intervention for critically ill patients. Delays in initiation, or an inability to resume CRRT following a temporary suspension in therapy (CRRT restart), can result in suboptimal CRRT delivery.

LOCAL PROBLEM

Intensive care units across the health care system were experiencing significant delays in CRRT initiation and restarts.

APPROACH

A multimodal quality improvement initiative was implemented across 7 adult intensive care units, which allowed unit-based staff nurses to initiate and restart CRRT, a task that had previously been delegated to non-unit-based dialysis nurses.

OUTCOMES

A 75% reduction in CRRT initiation delays and a 90% reduction in CRRT restart delays were observed in the 12 months following the initiative. There were no adverse events or increased disposable CRRT circuit usage following the initiative.

CONCLUSIONS

Implementation of CRRT initiation and restarts by unit-based nurses were achievable and resulted in substantial improvements in timeliness of CRRT delivery.

Effect of Blood Flow Rate on the Accuracy of Central Venous Pressure Measurement during Continuous Renal Replacement Therapy

BACKGROUND

The objective of this study was to study the influence of extracorporeal blood flow rate (BFR) on the accuracy of central venous pressure (CVP) measurement during continuous renal replacement therapy (CRRT).

METHODS

Eligible patients were randomly divided into 3 groups based on the location of catheters used for their CRRT and CVP measurement. CVP levels measured at increased extracorporeal BFR (from 0 to 300 mL/min) in the normal and reverse positions of inlet and outlet lines connected to the CV catheter (CVC) in the course of the CRRT session were collected.

RESULTS

CVP levels measured at different extracorporeal BFRs did not significantly differ between and among the 3 groups. Inversion of inlet and outlet lines connected to the catheters did not affect the accuracy of CVP measurement. BFR had a negative correlation with inflow/access pressure but a positive correlation with outflow/return pressure. Neither inflow pressure nor outflow pressure was correlated with CVP.

CONCLUSIONS

Extracorporeal BFR has no influence on the accuracy of CVP measurement during CRRT with the net machine balance adjusted to zero regardless of the location of the catheter and the connection method between catheters and CRRT lines. Thus, CRRT does not need to be discontinued to obtain an accurate CVP measurement.

Risk Factors and Prognosis of New-Onset Chronic Kidney Disease Following Orthotopic Liver Transplantation: A Retrospective Case-Control Study

BACKGROUND We have undertaken this investigation to explore the perioperative risk factors of new-onset chronic kidney disease (NOCKD) after orthotopic liver transplantation (OLT), and to provide an early prediction model for the screening of NOCKD high-risk populations. MATERIAL AND METHODS A retrospective case-control study was performed in adult recipients who received OLT in our center between January 2018 and January 2020. Perioperative data were collected using the center's electronic medical record system. Logistics regression analysis was used to determine risk factors for NOCKD within 1 year following OLT. Kaplan-Meier and log-rank tests were used to evaluate the 1-year survival of recipients with NOCKD or without NOCKD. RESULTS A total of 174 patients were included in this study, and 29 patients developed NOCKD after OLT. Logistic multivariate regression analysis showed that preoperative diabetes, high model for end-stage liver disease (MELD) score, postoperative acute kidney injury (AKI), and postoperative renal replacement therapy (RRT) were independent risk factors for NOCKD 1 year after OLT. The 1-year survival rate of NOCKD recipients waas significantly lower than that of patients who did not receive NOCKD. CONCLUSIONS Diabetes mellitus, MELD score, postoperative AKI, and requirement for postoperative RRT are independent risk factors for NOCKD after OLT, which may have great potential for personalized decision making and predicting the 1-year postoperative mortality of the recipient.

Serum Albumin Before CRRT Was Associated With the 28- and 90-Day Mortality of Critically Ill Patients With Acute Kidney Injury and Treated With Continuous Renal Replacement Therapy

Introduction: Although low serum albumin (ALB) may worsen acute kidney injury (AKI), additional study is needed to establish the connection between ALB and the prognosis of critically ill patients with AKI and treated with continuous renal replacement therapy (CRRT). Methods:A secondary analysis of a bi-center, retrospective, and observational study, such as critically ill patients with AKI and treated with CRRT from January 2009 to September 2016. The univariate analysis, multi-factor regression analysis, sensitivity analysis, and curve-fitting analysis were applied to explore the association of ALB with the 28 and 90 days mortality of critically ill patients with AKI and treated with CRRT, and the removal efficiency of serum phosphorus. Results: From January 2009 to September 2016, 1,132 cases with AKI and treated with CRRT met the inclusion criteria and enrolled in this study. We found that the higher ALB before CRRT, the lower the 28- and 90-day mortality of patients with AKI and treated with CRRT, the higher removal efficiency of serum phosphorus, the adjusted hazard ratio (HR) value for 28-day mortality in the four models were separately 0.92 (0.90, 0.95), 0.91 (0.89, 0.94), 0.92 (0.89, 0.95), and 0.92 (0.89, 0.95); the adjusted HR value for 90 day mortality in the four models were 0.91 (0.89, 0.94), 0.92 (0.89, 0.95), 0.92 (0.89, 0.95), and 0.92 (0.89, 0.96); the adjusted OR value for the removal efficiency of serum phosphorus in the four models were separately -0.04 (-0.07, -0.01), -0.05 (-0.08, -0.01), -0.04 (-0.08, -0.01), and -0.04 (-0.08, -0.01). The sensitivity analysis and curve-fitting analysis also showed that ALB before CRRT was correlated with the 28 and 90 days mortality of critically ill patients with AKI and treated with CRRT and the removal efficiency of serum phosphorus. Conclusion: The higher the serum ALB before CRRT, the lower the mortality of critically ill patients with AKI and treated with CRRT, and the higher the clearance efficiency of serum phosphorus.

Impact of different hemodiafiltration solutions on ionemia in long-term CRRT

Critical patients with Acute Kidney Injury (AKI) requiring renal replacement therapy are in most cases eligible only for continuous modalities where the electrolyte balance control is a critical issue. The standard solutions used for hemodiafiltration, containing potassium at 2 mmol/L and no phosphorus, determines during the extended renal replacement therapy hypokalemia and hypophosphatemia. Therefore, solutions containing potassium and phosphate in physiological concentrations were formulated to avoid electrolyte imbalances and reduce ion alterations in prolonged treatments, these solutions are not routinely used in the standard clinical practice. To avoid electrolyte imbalances, we have first introduced in our practice two different solutions and then we have retrospectively analyzed the electrolyte balance upon these two solutions in order to identity the impact of these solutions on potassium and phosphate according to our clinical practice. We retrospectively analyzed 96 patients treated with Continuous Renal Replacement Therapy (CRRT) in the intensive care units (ICU) at Padua's University Hospital to evaluate the role on electrolyte balance of Phoxilium^® and Prismasol 2^® that differ in their composition and the need for electrolytes infusions. In the Phoxilium group the frequency of hypokalemia, hypophosphatemia, and the need of potassium and phosphate replacement were significantly reduced resulting in a reduction in complications, workload, and clinical risk associated with infusions of electrolytes. Our data demonstrated that the use of these two different hemodiafiltration solutions can reduce the occurrence of hypokalemia and hypophosphatemia during CRRT performing personalized treatments without the use of potassium and phosphate infusions.

Urinary actin, as a potential marker of sepsis-related acute kidney injury: A pilot study

Introduction

A major complication of sepsis is the development of acute kidney injury (AKI). Recently, it was shown that intracellular actin released from damaged tissues appears in the urine of patients with multiple organ dysfunction syndrome. Our aims were to measure urinary actin (u-actin) concentrations of septic and control patients and to test if u-actin levels could predict AKI and mortality.

Methods

Blood and urine samples were collected from septic and sepsis-related AKI patients at three time points (T1-3): T1: within 24 hours after admission; T2: second day morning; T3: third day morning of follow-up. Patients with malignancies needing palliative care, end-stage renal disease or kidney transplantation were excluded. Serum and u-actin levels were determined by quantitative Western blot. Patients were categorized by the Sepsis-3 and KDIGO AKI classifications.

Results

In our study, 17 septic, 43 sepsis-induced AKI and 24 control patients were enrolled. U-actin levels were higher in septic patients compared with controls during follow-up (p<0.001). At T1, the septic and sepsis-related AKI groups also showed differences (p<0.001), yet this increase was not statistically significant at T2 and T3. We also detected significantly elevated u-actin concentrations in AKI-2 and AKI-3 septic patients compared with AKI-1 septic patients (p<0.05) at T1 and T3, along with a significant increase in AKI-2 septic patients compared with AKI-1 septic patients at T2 (p<0.01). This tendency remained the same when referring u-actin to urine creatinine. Parameters of first-day septic patient samples could discriminate AKI from non-AKI state (AUC ROC, p<0.001): u-actin: 0.876; se-creatinine: 0.875. Derived cut-off value for u-actin was 2.63 μg/L (sensitivity: 86.0%, specificity: 82.4%).

Conclusion

U-actin may be a complementary diagnostic biomarker to se-creatinine in sepsis-related AKI while higher u-actin levels also seem to reflect the severity of AKI. Further investigations may elucidate the importance of u-actin release in sepsis-related AKI.

Acute kidney injury

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

Acute kidney injury and continuous renal replacement therapy: A nursing perspective for my shift today in the intensive care unit

Handover, clinical discussion, and care for patients in the Intensive Care Unit (ICU) require visual cues to a verbal "story" in an attempt to quickly understand the patient status. Continuous renal replacement therapy (CRRT) is often associated with sepsis or a toxic cause and "kidney attack" not apparent to the patient; "silent" with no pain, discomfort, or vital sign changes initially. Language, terminology, and definitions for this acute kidney injury (AKI) are a graded classification with guidelines. CRRT and dialysis techniques use the physiological principles of diffusion and or convection for solute removal providing a replacement for the basic kidney functions to sustain life until function returns. When to stop CRRT is based on clinical assessment of the patient overall status and urine production re-starting. The medical treatment is focused on the key interventions of resuscitation, remove the cause, support with CRRT or dialysis and monitor for recovery of function. CRRT requires a multidisciplinary team and quality process, local policies, education, and competency pathways to promote best outcomes and efficacy.

Extracorporeal membrane oxygenation combined with continuous renal replacement therapy for the treatment of severe burns: current status and challenges

Severe burns often cause various systemic complications and multiple organ dysfunction syndrome, which is the main cause of death. The lungs and kidneys are vulnerable organs in patients with multiple organ dysfunction syndrome after burns. Extracorporeal membrane oxygenation (ECMO) and continuous renal replacement therapy (CRRT) have been gradually applied in clinical practice and are beneficial for severe burn patients with refractory respiratory failure or renal dysfunction. However, the literature on ECMO combined with CRRT for the treatment of severe burns is limited. Here, we focus on the current status of ECMO combined with CRRT for the treatment of severe burns and the associated challenges, including the timing of treatment, nutrition support, heparinization and wound management, catheter-related infection and drug dosing in CRRT. With the advancement of medical technology, ECMO combined with CRRT will be further optimized to improve the outcomes of patients with severe burns.

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.

A systematic review of cost-effectiveness analyses of continuous versus intermittent renal replacement therapy in acute kidney injury

INTRODUCTION

Though cost-effectiveness analyses (CEAs) have evaluated continuous renal replacement therapy (RRTs) and intermittent RRTs in acute kidney injury (AKI) patients; it is yet to establish which RRT technique is most cost-effective. We systematically reviewed the current evidence from CEAs of CRRT versus IRRT in patients with AKI.

AREAS COVERED

PubMed, EMBASE, and Cochrane databases searched for CEAs comparing two RRTs. Overall, seven CEAs, two from Brazil and one from US, Canada, Colombia, Belgium, and Argentina were included. Five CEAs used Markov model, three reported following CHEERS, none accounted indirect costs. Time horizon varied from 1-year-lifetime. Marginal QALY gain with CRRT compared to IRRT was reported across CEAs. Older CEAs found CRRT to be costlier and not cost-effective than IRRT (ICER 2019 US$: 152,671$/QALY); latest CEAs (industry-sponsored) reported CRRT to be cost-saving versus IRRT (-117,614$/QALY). Risk of mortality, dialysis dependence, and incidence of renal recovery were the key drivers of cost-effectiveness.

EXPERT OPINION

CEAs of RRTs for AKI show conflicting findings with secular trends. Latest CEAs suggested CRRT to be cost-effective versus IRRT with dialysis dependence rate as major driver of cost-effectiveness. Future CEAs, preferably non-industry sponsored, may account for indirect costs to improve the generalizability of CEAs.

Low bicarbonate replacement fluid normalizes metabolic alkalosis during continuous veno-venous hemofiltration with regional citrate anticoagulation

Background

Metabolic alkalosis is a frequently occurring problem during continuous veno-venous hemofiltration (CVVH) with regional citrate anticoagulation (RCA). This study aimed to evaluate the effectiveness of switching from high to low bicarbonate (HCO₃⁻) replacement fluid in alkalotic critically ill patients with acute kidney injury treated by CVVH and RCA.

Methods

A retrospective-comparative study design was applied. Patients who underwent CVVH with RCA in the ICU between 09/2016 and 11/2017 were evaluated. Data were available from the clinical routine. A switch of the replacement fluid Phoxilium^® (30 mmol/l HCO₃⁻) to Biphozyl^® (22 mmol/l HCO₃⁻) was performed as blood HCO₃⁻ concentration persisted ≥ 26 mmol/l despite adjustments of citrate dose and blood flow. Data were collected from 72 h before the switch of the replacement solutions until 72 h afterwards.

Results

Of 153 patients treated with CVVH during that period, 45 patients were switched from Phoxilium^® to Biphozyl^®. Forty-two patients (42 circuits) were available for statistical analysis. After switching the replacement fluid from Phoxilium^® to Biphozyl^® the serum HCO₃⁻ concentration decreased significantly from 27.7 mmol/l (IQR 26.9–28.9) to 25.8 mmol/l (IQR 24.6–27.7) within 24 h (p < 0.001). Base excess (BE) decreased significantly from 4.0 mmol/l (IQR 3.1–5.1) to 1.8 mmol/l (IQR 0.2–3.4) within 24 h (p < 0.001). HCO₃⁻ and BE concentration remained stable from 24 h till the end of observation at 72 h after the replacement fluid change (p = 0.225). pH and PaCO₂ did not change significantly after the switch of the replacement fluid until 72 h.

Conclusions

This retrospective analysis suggests that for patients developing refractory metabolic alkalosis during CVVH with RCA the use of Biphozyl^® reduces external HCO₃⁻ load and sustainably corrects intracorporeal HCO₃⁻ and BE concentrations. Future studies have to prove whether correcting metabolic alkalosis during CVVH with RCA in critically ill patients is of relevance in terms of clinical outcome.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13613-021-00850-4.

Anticoagulation strategies in continuous renal replacement therapy

The most common anticoagulant options for continuous renal replacement therapy (CRRT) include unfractionated heparin (UFH), regional citrate anticoagulation (RCA), and no anticoagulation. Less common anticoagulation options include UFH with protamine reversal, low-molecular weight heparin (LMWH), thrombin antagonists, and platelet inhibiting agents. The choice of anticoagulant for CRRT should be determined by patient characteristics, local expertise, and ease of monitoring. The Kidney Disease Improving Global Outcomes (KDIGO) acute kidney injury guidelines recommend using RCA rather than UFH in patients who do not have contraindications to citrate and are with or without increased risk of bleeding. Monitoring should include evaluation of the anticoagulant effect, circuit life, filter efficacy, and complications.

Continuous Renal Replacement Therapy: A Review of Use and Application in Pediatric Hematopoietic Stem Cell Transplant Recipients

Hematopoietic stem cell transplant (HSCT) is a curative therapy for malignant and non-malignant conditions. However, complications post-HSCT contribute to significant morbidity and mortality in this population. Acute kidney injury (AKI) is common in the post-allogeneic transplant phase and contributes to morbidity in this population. Continuous renal replacement therapy (CRRT) is used often in the setting of AKI or multiorgan dysfunction in critically ill children. In addition, CRRT can be useful in many disease processes related to transplant and can potentially improve outcomes in this population. This review will focus on the use of CRRT in critically ill children in the post-HSCT setting outside the realm of acute renal failure and highlight the benefits and applications of this modality in this high-risk population.

Development and evaluation of a decision aid for family surrogate decision-makers for patients with acute kidney injury requiring renal replacement therapy (RRT) in ICUs: a study protocol

INTRODUCTION

Shared decision making is endorsed by guidelines for both acute kidney injury and critical care medicine. However, there is still a huge need for effective interventions, especially those focusing on decisions about renal replacement therapy for intensive care unit (ICU) patients with acute kidney injury. The decision aids provide evidence-based support for shared decision making, to achieve better decisions through enhanced knowledge of treatment options and treatment aligns with patients' preferences and values. Therefore, our objectives are to develop and evaluate a decision aid systematically and rigorously for family surrogate decision makers of ICU patients with acute kidney injury who need renal replacement therapy.

METHODS AND ANALYSIS

We will use a systematic development process that focuses on user-centred design to develop and evaluate the decision aid in three phases: (1) development of a draft prototype for the decision aid based on extensive literature reviews, interviews with key stakeholders and evidence synthesis; (2) alpha testing ('near live' usability) the decision aid during simulated clinical encounters to test its comprehensibility, acceptability and usability and (3) beta testing ('live' usability) to examine the aid's clinical feasibility. User testing will be conducted using mixed-methods approach to support iterative revision of the decision aid. The IPDASi (V.4.0) will be used for following qualitative assessment. All interviews will be analysed by Colaizzi's seven-step approach to qualitative analysis. The coding scheme will use to analyse user interactions. Questionnaire surveys will be analysed using paired sample t-tests when related to the before-and-after survey, otherwise using one-sample t-test.

ETHICS AND DISSEMINATION

Ethical approval for this research was obtained from the Ethics Committee of the First Affiliated Hospital of Army Medical University, PLA (Ref: KY2020104). All participants will sign a formal informed consent form. The findings will be published in peer-reviewed journals and reported in appropriate meetings.

TRIAL REGISTRATION NUMBER

ChiCTR2000031613.

Modeling acid-base balance during continuous kidney replacement therapy

Clinical studies have suggested that use of bicarbonate-containing substitution and dialysis fluids during continuous kidney replacement therapy may result in excessive increases in the carbon dioxide concentration of blood; however, the technical parameters governing such changes are unclear. The current work used a mathematical model of acid-base chemistry of blood to predict its composition within and exiting the extracorporeal circuit during continuous veno-venous hemofiltration (CVVH) and continuous veno-venous hemodiafiltration (CVVHDF). Model predictions showed that a total substitution fluid infusion rate of 2 L/h (33% predilution) with a bicarbonate concentration of 32 mEq/L during CVVH at a blood flow rate of 200 mL/min resulted in only modest increases in plasma bicarbonate concentration by 2.0 mEq/L and partial pressure of dissolved carbon dioxide by 4.4 mmHg in blood exiting the extracorporeal circuit. The relative increase in bicarbonate concentration (9.7%) was similar to that in partial pressure of dissolved carbon dioxide (8.2%), resulting in no significant change in plasma pH in the blood exiting the CVVH circuit. The changes in plasma acid-base levels were larger with a higher infusion rate of substitution fluid but smaller with a higher blood flow rate or use of substitution fluid with a lower bicarbonate concentration (22 mEq/L). Under comparable flow conditions and substitution fluid composition, model predicted changes in acid-base levels during CVVHDF were similar, but smaller, than those during CVVH. The described mathematical model can predict the effect of operating conditions on acid-base balance within and exiting the extracorporeal circuit during continuous kidney replacement therapy.

Extracorporeal Membrane Oxygenation and Continuous Kidney Replacement Therapy: Technology and Outcomes - A Narrative Review

The number of patients using critical care is increasing as our populations live longer thanks to advances in medical therapies. This is reflected by an increase in both usage and number of critical care beds as compared with total hospital beds across the United States. As this aging population suffers more and more from multiorgan dysfunction, including but not limited to respiratory failure, cardiac failure, and acute kidney injury, technologies are used to facilitate recovery in those that would have assuredly passed away years ago. Some of these advancements include extracorporeal membrane oxygenation and continuous kidney replacement therapy. In this article, we review the literature regarding the history, technology, indications, and outcomes of synchronous extracorporeal membrane oxygenation and kidney replacement therapy.

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.

Factors Associated with In-Hospital Mortality after Continuous Renal Replacement Therapy for Critically Ill Patients: A Systematic Review and Meta-Analysis

Continuous renal replacement therapy (CRRT) is a broadly-accepted treatment for critically ill patients with acute kidney injury to optimize fluid and electrolyte management. Despite intensive dialysis care, there is a high mortality rate among these patients. There is uncertainty regarding the factors associated with in-hospital mortality among patients requiring CRRT. This review evaluates how various risk factors influence the in-hospital mortality of critically ill patients who require CRRT. Five databases were surveyed to gather relevant publications up to 30 June 2020. We identified 752 works, of which we retrieved 38 in full text. Finally, six cohort studies that evaluated 1190 patients were eligible. The in-hospital mortality rate in these studies ranged from 38.6 to 62.4%. Our meta-analysis results showed that older age, lower body mass index, higher APACHE II and SOFA scores, lower systolic and diastolic blood pressure, decreased serum creatinine level, and increased serum sodium level were significantly associated with increased in-hospital mortality in critically ill patients who received CRRT. These results suggest that there are multiple modifiable factors that influence the risk of in-hospital mortality in critically ill patients undergoing CRRT. Further, healthcare professionals should take more care when CRRT is performed on older adults.

Comparison of different anticoagulation strategies for renal replacement therapy in critically ill patients with COVID-19: a cohort study

BACKGROUND

Critically ill coronavirus disease 2019 (COVID-19) patients have a high risk of acute kidney injury (AKI) that requires renal replacement therapy (RRT). A state of hypercoagulability reduces circuit life spans. To maintain circuit patency and therapeutic efficiency, an optimized anticoagulation strategy is needed. This study investigates whether alternative anticoagulation strategies for RRT during COVID-19 are superior to administration of unfractionated heparin (UFH).

METHODS

Retrospective cohort study on 71 critically ill COVID-19 patients (≥18 years), admitted to intensive care units at a tertiary health care facility in the southwestern part of Germany between February 26 and May 21, 2020. We collected data on the disease course, AKI, RRT, and thromboembolic events. Four different anticoagulatory regimens were administered. Anticoagulation during continuous veno-venous hemodialysis (CVVHD) was performed with UFH or citrate. Anticoagulation during sustained low-efficiency daily dialysis (SLEDD) was performed with UFH, argatroban, or low molecular weight heparin (LMWH). Primary outcome is the effect of the anticoagulation regimen on mean treatment times of RRT.

RESULTS

In patients receiving CVVHD, mean treatment time in the UFH group was 21.3 h (SEM: ±5.6 h), in the citrate group 45.6 h (SEM: ±2.7 h). Citrate anticoagulation significantly prolonged treatment times by 24.4 h (P = .001). In patients receiving SLEDD, mean treatment time with UFH was 8.1 h (SEM: ±1.3 h), with argatroban 8.0 h (SEM: ±0.9 h), and with LMWH 11.8 h (SEM: ±0.5 h). LMWH significantly prolonged treatment times by 3.7 h (P = .008) and 3.8 h (P = .002), respectively.

CONCLUSIONS

UFH fails to prevent early clotting events in the dialysis circuit during COVID-19. For patients, who do not require effective systemic anticoagulation, regional citrate dialysis is the most effective strategy. For patients, who require effective systemic anticoagulation, the usage of LMWH results in the longest circuit life spans. The proposed anticoagulatory strategies are safe, can easily be monitored, and allow an individualized treatment.

Acute Kidney Injury in Septic Patients Treated by Selected Nephrotoxic Antibiotic Agents-Pathophysiology and Biomarkers-A Review

Acute kidney injury is a common complication in critically ill patients with sepsis and/or septic shock. Further, some essential antimicrobial treatment drugs are themselves nephrotoxic. For this reason, timely diagnosis and adequate therapeutic management are paramount. Of potential acute kidney injury (AKI) biomarkers, non-protein-coding RNAs are a subject of ongoing research. This review covers the pathophysiology of vancomycin and gentamicin nephrotoxicity in particular, septic AKI and the microRNAs involved in the pathophysiology of both syndromes. PubMED, UptoDate, MEDLINE and Cochrane databases were searched, using the terms: biomarkers, acute kidney injury, antibiotic nephrotoxicity, sepsis, miRNA and nephrotoxicity. A comprehensive review describing pathophysiology and potential biomarkers of septic and toxic acute kidney injury in septic patients was conducted. In addition, five miRNAs: miR-15a-5p, miR-192-5p, miR-155-5p, miR-486-5p and miR-423-5p specific to septic and toxic acute kidney injury in septic patients, treated by nephrotoxic antibiotic agents (vancomycin and gentamicin) were identified. However, while these are at the stage of clinical testing, preclinical and clinical trials are needed before they can be considered useful biomarkers or therapeutic targets of AKI in the context of antibiotic nephrotoxicity or septic injury.

Kidney Replacement Therapy in COVID-19 Induced Kidney Failure and Septic Shock: A Pediatric Continuous Renal Replacement Therapy [PCRRT] Position on Emergency Preparedness With Resource Allocation

The recent worldwide pandemic of COVID-19 has had a detrimental worldwide impact on people of all ages. Although data from China and the United States indicate that pediatric cases often have a mild course and are less severe in comparison to adults, there have been several cases of kidney failure and multisystem inflammatory syndrome reported. As such, we believe that the world should be prepared if the severity of cases begins to further increase within the pediatric population. Therefore, we provide here a position paper centered on emergency preparation with resource allocation for critical COVID-19 cases within the pediatric population, specifically where renal conditions worsen due to the onset of AKI.