Early mortality on continuous renal replacement therapy (CRRT): the prairie CRRT study

Kidney Outcomes Following Utilization of Molecular Adsorbent Recirculating System

Introduction

Molecular adsorbent recirculating system (MARS) is an extracorporeal system combining conventional veno-venous hemodiafiltration and adsorption to provide rescue support in fulminant hepatic failure. Acute kidney injury (AKI) is common in patients with hepatic failure warranting continuous kidney replacement therapy (CKRT). Our primary aim was to characterize a cohort of patients who received MARS therapy and examine kidney events given the current paucity of available data.

Methods

Patients initiating MARS in a tertiary care setting from January 2014 through December 2020 were assessed for treatment indications, transplantation, CKRT, kidney recovery, and death. Data was collected using the REDCAP software.

Results

A total of 49 patients (67% female; 75% White) received MARS therapy with 29 patients (59%) requiring concomitant CKRT. Hepatic encephalopathy (HE) was the most common indication for MARS initiation (55%). In-hospital mortality was 41% (12/29) among patients who received CKRT versus 10% (2/20) among those not requiring CKRT (relative risk [RR] 4.15, 95% confidence interval [CI] 1.04 to 16.52, P = 0.044); this persisted following adjustment for prespecified patient characteristics (all RR ≥ 3.76, all P ≤ 0.060). One-year mortality post-MARS initiation was high overall but highest among the CKRT group (59% [17/29] vs. 25% [5/20] unadjusted RR 2.92, 95% CI 1.08 to 7.94, P = 0.035). Liver transplant after MARS occurred in 41% of patients (20/49). After CKRT, 39% of patients (9/29) recovered kidney function prior to hospital discharge.

Conclusions

Patients requiring MARS frequently have AKI warranting the use of concomitant CKRT, which is associated with a high rate of in-hospital and 1-year mortality.

Diagnostic and Prognostic Roles of C-Reactive Protein, Procalcitonin, and Presepsin in Acute Kidney Injury Patients Initiating Continuous Renal Replacement Therapy

For reducing the high mortality rate of severe acute kidney injury (AKI) patients initiating continuous renal replacement therapy (CRRT), diagnosing sepsis and predicting prognosis are essential. However, with reduced renal function, biomarkers for diagnosing sepsis and predicting prognosis are unclear. This study aimed to assess whether C-reactive protein (CRP), procalcitonin, and presepsin could be used to diagnose sepsis and predict mortality in patients with impaired renal function initiating CRRT. This was a single-center, retrospective study involving 127 patients who initiated CRRT. Patients were divided into sepsis and non-sepsis groups according to the SEPSIS-3 criteria. Of the 127 patients, 90 were in the sepsis group and 37 were in the non-sepsis group. Cox regression analysis was performed to determine the association between the biomarkers (CRP, procalcitonin, and presepsin) and survival. CRP and procalcitonin were superior to presepsin for diagnosing sepsis. Presepsin was closely related to the estimated glomerular filtration rate (eGFR) (r = -0.251, p = 0.004). These biomarkers were also evaluated as prognostic markers. Procalcitonin levels ≥3 ng/mL and CRP levels ≥31 mg/L were associated with higher all-cause mortality using Kaplan-Meier curve analysis. (log-rank test p = 0.017 and p = 0.014, respectively). In addition, procalcitonin levels ≥3 ng/mL and CRP levels ≥31 mg/L were associated with higher mortality in univariate Cox proportional hazards model analysis. In conclusion, a higher lactic acid, sequential organ failure assessment score, eGFR, and a lower albumin level have prognostic value to predict mortality in patients with sepsis initiating CRRT. Moreover, among these biomarkers, procalcitonin and CRP are significant factors for predicting the survival of AKI patients with sepsis-initiating CRRT.

Consulting to nephrologist when starting continuous renal replacement therapy for acute kidney injury is associated with a survival benefit

BACKGROUND

Several studies suggest improved outcomes for patients with kidney disease who consult a nephrologist. However, it remains undetermined whether a consultation with a nephrologist is related to a survival benefit after starting continuous renal replacement therapy (CRRT) due to acute kidney injury (AKI).

METHODS

Data from 2,397 patients who started CRRT due to severe AKI at Seoul National University Hospital, Korea between 2010 and 2020 were retrospectively collected. The patients were divided into two groups according to whether they underwent a nephrology consultation regarding the initiation and maintenance of CRRT. The Cox proportional hazards model was used to calculate the hazard ratio (HR) of mortality during admission to the intensive care unit after adjusting for multiple variables.

RESULTS

A total of 2,153 patients (89.8%) were referred to nephrologists when starting CRRT. The patients who underwent a nephrology consultation had a lower mortality rate than those who did not have a consultation (HR = 0.47 [0.40-0.56]; P < 0.001). Subsequently, patients who had nephrology consultations were divided into two groups (i.e., early and late) according to the timing of the consultation. Both patients with early and late consultation had lower mortality rates than patients without consultations, with HRs of 0.45 (0.37-0.54) and 0.51 (0.42-0.61), respectively.

CONCLUSIONS

Consultation with a nephrologist may contribute to a survival benefit after starting CRRT for AKI.

Longitudinal trajectory of acidosis and mortality in acute kidney injury requiring continuous renal replacement therapy

BACKGROUND

Acidosis frequently occurs in severe acute kidney injury (AKI), and continuous renal replacement therapy (CRRT) can control this pathologic condition. Nevertheless, acidosis may be aggravated; thus, monitoring is essential after starting CRRT. Herein, we addressed the longitudinal trajectory of acidosis on CRRT and its relationship with worse outcomes.

METHODS

The latent growth mixture model was applied to classify the trajectories of pH during the first 24 hours and those of C-reactive protein (CRP) after 24 hours on CRRT due to AKI (n = 1815). Cox proportional hazard models were used to calculate hazard ratios of all-cause mortality after adjusting multiple variables or matching their propensity scores.

RESULTS

The patients could be classified into 5 clusters, including the normally maintained groups (1st cluster, pH = 7.4; and 2nd cluster, pH = 7.3), recovering group (3rd cluster with pH values from 7.2 to 7.3), aggravating group (4th cluster with pH values from 7.3 to 7.2), and ill-being group (5th cluster, pH < 7.2). The pH clusters had different trends of C-reactive protein (CRP) after 24 hours; the 1st and 2nd pH clusters had lower levels, but the 3rd to 5th pH clusters had an increasing trend of CRP. The 1st pH cluster had the best survival rates, and the 3rd to 5th pH clusters had the worst survival rates. This survival difference was significant despite adjusting for other variables or matching propensity scores.

CONCLUSIONS

Initial trajectories of acidosis determine subsequent worse outcomes, such as mortality and inflammation, in patients undergoing CRRT due to AKI.

Development of New Equations Predicting the Mortality Risk of Patients on Continuous RRT

Background

Predicting the risk of death in patients admitted to the critical care unit facilitates appropriate management. In particular, among patients who are critically ill, patients with continuous RRT (CRRT) have high mortality, and predicting the mortality risk of these patients is difficult. The purpose of this study was to develop models for predicting the mortality risk of patients on CRRT and to validate the models externally.

Methods

A total of 699 adult patients with CRRT who participated in the VolumE maNagement Under body composition monitoring in critically ill patientS on CRRT (VENUS) trial and 1515 adult patients with CRRT in Seoul National University Hospital were selected as the development and validation cohorts, respectively. Using 11 predictor variables selected by the Cox proportional hazards model and clinical importance, equations predicting mortality within 7, 14, and 28 days were developed with development cohort data.

Results

The equation using 11 variables had area under the time-dependent receiver operating characteristic curve (AUROC) values of 0.75, 0.74, and 0.73 for predicting 7-, 14-, and 28-day mortality, respectively. All equations had significantly higher AUROCs than the Sequential Organ Failure Assessment (SOFA) and Acute Physiology and Chronic Health Evaluation II (APACHE II) scores. The 11-variable equation was superior to the SOFA and APACHE II scores in the integrated discrimination index and net reclassification improvement analyses.

Conclusions

The newly developed equations for predicting CRRT patient mortality showed superior performance to the previous scoring systems, and they can help physicians manage patients.

Predictors of early mortality in critically ill patients with acute kidney injury necessitating renal replacement therapy: A cohort study

PURPOSE

Reliable prediction of early mortality after initiation of renal replacement therapy (RRT) in critically ill patients may inform decision-making regarding this treatment. Our primary objective was to identify predictors of mortality within 2 days of starting RRT.

MATERIALS AND METHODS

Patients with acute kidney injury (AKI), receiving RRT, and admitted to intensive care units of one hospital were included. Associations between baseline risk factors and mortality at 2 days and at hospital discharge were analyzed using logistic regression. Discrimination of both models was assessed.

RESULTS

We included 626 patients, treated initially with intermittent RRT (n = 300, 47.9%), continuous RRT (n = 211, 33.7%), or sustained low-efficiency dialysis (n = 115, 18.4%). Two-day mortality after starting RRT was 12.9% (n = 81), and hospital mortality was 50.5% (n = 316). Independent predictors of 2-day mortality included primary diagnostic category (p = 0.004) and sepsis-related organ failure assessment (SOFA) score (odds ratio [OR] 1.36 per point, 95% confidence interval [CI] 1.24-1.50). Independent predictors of hospital mortality included SOFA (1.29, 95%CI 1.21-1.37), Charlson score (1.20, 95%CI 1.18-1.43), and interhospital transfer (OR 0.55, 0.38-0.81). C-statistics were 0.81 (2-day mortality) and 0.80 (hospital mortality).

CONCLUSIONS

Higher SOFA was associated with 2-day mortality after RRT initiation and with hospital mortality. Discrimination in both models was modest.

The landscape of renal replacement therapy in Veterans Affairs Medical Center intensive care units

Background

Outpatient dialysis is standardized with several evidence-based measures of adequacy and quality that providers aim to meet while providing treatment. By contrast, in the intensive care unit (ICU) there are different types of prolonged and continuous renal replacement therapies (PIRRT and CRRT, respectively) with varied strategies for addressing patient care and a dearth of nationally accepted quality parameters. To eventually describe appropriate quality measures for ICU-related renal replacement therapy (RRT), we first aimed to capture the variety and prevalence of basic strategies and equipment utilized in the ICUs of Veteran Affairs (VA) medical facilities with inpatient hemodialysis capabilities.

Methods

Via email to the dialysis directors of all VA facilities that provided inpatient hemodialysis during 2018, we requested survey participation regarding aspects of RRT in VA ICUs. Questions centered around the mode of therapy, equipment, solutions, prescription authority, nursing, anticoagulation, antimicrobial dosing, and access.

Results

Seventy-six centers completed the questionnaire, achieving a response rate of 87.4%. Fifty-five centers reported using PIRRT or CRRT in addition to intermittent hemodialysis. Of these centers, 42 reported being specifically CRRT-capable. Over half of respondents had the capabilities to perform PIRRT. Twelve centers (21.8%) were equipped to use slow low efficient dialysis (SLED) alone. Therapy was largely prescribed by nephrologists (94.4% of centers).

Conclusions

Within the VA system, ICU-related RRT practice is quite varied. Variation in processes of care, prescription authority, nursing care coordination, medication management, and safety practices present opportunities for developing cross-cutting measures of quality of intensive care RRT that are agnostic of modality choice.

Mortality predictors in critically ill patients with acute kidney injury requiring continuous renal replacement therapy

Background

Because of high cost of continuous renal replacement therapy (CRRT) and the high mortality rate among severe acute kidney injury patients, careful identification of patients who will benefit from CRRT is warranted. This study determined factors associated with mortality among critically ill patients requiring CRRT.

Methods

This was a retrospective observational study of 414 patients admitted to the intensive care unit of four hospitals in South Korea who received CRRT from June 2017 to September 2018. Patients were divided according to degree of fluid overload (FO) and disease severity. The Cox proportional hazards model was used to explore the effect of relevant variables on mortality.

Results

In-hospital mortality rate was 57.2%. Ninety-day mortality rate was 58.5%. Lower creatinine and blood pH were significant predictors of mortality. A one-unit increase in the Sequential Organ Failure Assessment (SOFA) score was associated with increased risk of and 90-day mortality (hazard ratio [HR], 1.07; p < 0.001). The risk of 90-day mortality in FO patients was 57.2% (p < 0.001) higher than in those without FO. High SOFA score was associated with increased risk for 90-day mortality (HR, 1.79; p = 0.03 and HR, 3.05; p = 0.001) in patients without FO and with FO ≤ 10%, respectively. The highest mortality rates were in patients with FO > 10%, independent of disease severity.

Conclusion

FO increases the risk of mortality independent of other factors, including severity of acute illness. Prevention of FO should be a priority, especially when managing the critically ill.

Comparison of Approaches for Prediction of Renal Replacement Therapy-Free Survival in Patients with Acute Kidney Injury

BACKGROUND/AIMS

Acute kidney injury (AKI) in critically ill patients is common, and continuous renal replacement therapy (CRRT) is a preferred mode of renal replacement therapy (RRT) in hemodynamically unstable patients. Prediction of clinical outcomes in patients on CRRT is challenging. We utilized several approaches to predict RRT-free survival (RRTFS) in critically ill patients with AKI requiring CRRT.

METHODS

We used the Medical Information Mart for Intensive Care (MIMIC-III) database to identify patients ≥18 years old with AKI on CRRT, after excluding patients who had ESRD on chronic dialysis, and kidney transplantation. We defined RRTFS as patients who were discharged alive and did not require RRT ≥7 days prior to hospital discharge. We utilized all available biomedical data up to CRRT initiation. We evaluated 7 approaches, including logistic regression (LR), random forest (RF), support vector machine (SVM), adaptive boosting (AdaBoost), extreme gradient boosting (XGBoost), multilayer perceptron (MLP), and MLP with long short-term memory (MLP + LSTM). We evaluated model performance by using area under the receiver operating characteristic (AUROC) curves.

RESULTS

Out of 684 patients with AKI on CRRT, 205 (30%) patients had RRTFS. The median age of patients was 63 years and their median Simplified Acute Physiology Score (SAPS) II was 67 (interquartile range 52-84). The MLP + LSTM showed the highest AUROC (95% CI) of 0.70 (0.67-0.73), followed by MLP 0.59 (0.54-0.64), LR 0.57 (0.52-0.62), SVM 0.51 (0.46-0.56), AdaBoost 0.51 (0.46-0.55), RF 0.44 (0.39-0.48), and XGBoost 0.43 (CI 0.38-0.47).

CONCLUSIONS

A MLP + LSTM model outperformed other approaches for predicting RRTFS. Performance could be further improved by incorporating other data types.

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.

Markers of Poor Prognosis in Patients Requiring Continuous Renal Replacement Therapy After Cardiac Surgery

OBJECTIVE

Acute kidney injury requiring renal replacement therapy after cardiac surgery has an incidence of 2% to 15%, and mortality in affected patients approximates 50%. The authors aimed to study the determinants of poor prognosis in patients receiving continuous renal replacement therapy (CRRT) after cardiac surgery.

DESIGN

Retrospective, observational single-center study.

SETTING

Tertiary care, university hospital.

PARTICIPANTS

Cardiac surgery patients admitted to the intensive care unit (ICU) needing postoperative CRRT between January 1, 2010, and September 31, 2019.

INTERVENTIONS

Predictors of mortality were examined using groupwide comparisons between ICU survivors versus nonsurvivors and univariate and multivariate Cox proportional hazards models.

RESULTS

During the study period, 67 cardiac surgery patients without prior maintenance dialysis required CRRT postoperatively. ICU mortality was 47.7% and 90-day mortality was 58.2%. Only 37.3% of patients were alive at 1 year after surgery. Blood lactate at the start of dialysis was the most significant predictor of ICU and overall mortality. Eighty-seven percent of patients with lactate >3 mmol/L died in the ICU compared with 27.3% of patients with lactate ≤3 mmol/L (p < 0.0001). In patients with lactate exceeding 5.3 mmol/L, ICU mortality was 100%. In a stepwise multivariate Cox proportional hazards model, the association with mortality remained significant for lactate at the start of CRRT (per 1 mmol/L, hazard ratio [HR] 1.19 [95% confidence interval {CI} 1.11-1.28], p < 0.0001), troponin T on the first postoperative morning (per 0.1 µg/L, HR 1.004 [95% CI 1.001-1.008], p = 0.01), and 72-hour fluid balance (per 1000 mL, HR 1.12 [95% CI 1.04-1.21], p = 0.005).

CONCLUSION

Blood lactate at the start of dialysis was the most significant predictor of ICU and overall mortality in patients with CRRT after cardiac surgery.

Predictors of 15-Day Survival for the Intensive Care Unit Patient on Continuous Renal Replacement Therapy: A Retrospective Analysis

Purpose

In the intensive care unit (ICU), acute renal failure is mostly part of multiple organ dysfunction syndromes with mortality ranging from 28%-90%, continuous renal replacement therapy (CRRT) is the predominant mode of RRT used in ICU. The main objective of the study was to evaluate the outcomes in patients with acute kidney injury (AKI) on CRRT in the ICU.

Methods

A retrospective chart review was conducted for all ICU patients with acute renal failure on CRRT in a tertiary care teaching hospital. A subgroup analysis was conducted between 15 days in hospital survivors and non-survivors to look for predictors of survival for patients on CRRT.

Results

Two-hundred twenty-six patients underwent CRRT from January 2007 to December 2013. The overall in-hospital mortality was 84.1%. Fifty-six patients (24.77%) survived to the 15-day post-CRRT mark. Acute respiratory failure requiring mechanical ventilation was associated with significantly increased mortality; 89.2% vs. 97.6% (P=0.008), ICU length of stay was significantly longer in the survivor group than the nonsurvivor group. Median±IQR; {20±24 vs 6±7(P: <0.0001)} and so were the ventilator-associated days {16±24 vs 4±6.5 (P: <0.0001)} and duration of CRRT {4.5±5.5 vs 2±2.0(P: <0.0001)}. Patients who survived had a lower incidence of metabolic acidosis {44.6% vs 62.9% (P: 0. 016)} and uremic encephalopathy {12.5% vs 26.5%; (P: 0.031)} but a greater incidence of volume overload {28.6% vs 15.9% (P: 0.031)} as compared to the non-survivor. Acute Physiology And Chronic Health Evaluation II (APACHE II) scores were significantly higher in the non-survivor group (mean SD) 26.9±28.0 vs. 23.9±25.8 (P: 0.0136).

Conclusions

This observational study in patients undergoing CRRT in an ICU setting revealed that the overall mortality was 84.1%. Fluid overload as an indication of CRRT was associated with improved 15 days’ survival whereas higher APACHE II scores and the use of mechanical ventilation were associated with reduced 15 days’ survival.

Continuous renal replacement therapy in patients with HIV/AIDS

Background

Acute kidney injury (AKI) is a common complication among human immunodeficiency virus (HIV)-infected patients resulting in increased morbidity and mortality. Continuous renal replacement therapy (CRRT) is a useful method and instrument in critically ill patients with fluid overload and metabolic disarray, especially in those who are unable to tolerate the intermittent hemodialysis. However, the epidemiology, influence factors of CRRT and mortality in patients with HIV/AIDS are still unclear in China. This study aims to study the HIV-infected patients admitted in Intensive Care Unit (ICU) and explore the influence factors correlated with CRRT and their prognosis.

Methods

We performed a retrospective case-control study in the ICU of the Beijing Ditan Hospital Capital Medical University. From June 1, 2005 to May 31, 2017, 225 cases were enrolled in this clinical study.

Results

122 (54.2%) patients were diagnosed with AKI during their stay in ICU, the number and percentage of AKI stage 1, 2 and 3 were 38 (31.1%), 21(17.2%) and 63(51.7%), respectively. 26.2% of AKI patients received CRRT during the stay of ICU. 56.25% CRRT patients died in ICU. The 28-day mortality was 62.5%, and the 90-day mortality was 75%. By univariate logistics analysis, it showed that higher likelihood of diagnosis for respiratory failure (OR = 7.333,95% CI 1.467–36.664, p = 0.015), higher likelihood of diagnosis for septic shock (OR = 1.005,95% CI 1.001–1.01, p = 0.018), and higher likelihood to use vasoactive agents (OR = 10.667,95% CI 1.743–65.271, p = 0.001), longer mechanical ventilation duration (OR = 1.011,95% CI 1.002–1.019, p = 0.011), higher likelihood for diagnosis for PCP (OR = 7.50,95% CI 1.288–43.687, p = 0.025), higher SOFA score at ICU admission (OR = 1.183,95% CI 1.012–1.383, p = 0.035), longer duration of CRRT (OR = 1.014,95% CI 1.001–1.028, p = 0.034) contributed to a higher mortality at ICU. The Cox Analysis for the cumulative survival of AKI 3 patients between the CRRT and non-CRRT groups shows no significant differences (p = 0.595).

Conclusions

There is a high incidence of AKI in HIV-infected patients admitted in our ICU. Patients with severe AKI were more prone to be admitted for CRRT and have a consequent poor prognosis.

Machine learning algorithm to predict mortality in patients undergoing continuous renal replacement therapy

Background

Previous scoring models such as the Acute Physiologic Assessment and Chronic Health Evaluation II (APACHE II) and the Sequential Organ Failure Assessment (SOFA) scoring systems do not adequately predict mortality of patients undergoing continuous renal replacement therapy (CRRT) for severe acute kidney injury. Accordingly, the present study applies machine learning algorithms to improve prediction accuracy for this patient subset.

Methods

We randomly divided a total of 1571 adult patients who started CRRT for acute kidney injury into training (70%, n = 1094) and test (30%, n = 477) sets. The primary output consisted of the probability of mortality during admission to the intensive care unit (ICU) or hospital. We compared the area under the receiver operating characteristic curves (AUCs) of several machine learning algorithms with that of the APACHE II, SOFA, and the new abbreviated mortality scoring system for acute kidney injury with CRRT (MOSAIC model) results.

Results

For the ICU mortality, the random forest model showed the highest AUC (0.784 [0.744–0.825]), and the artificial neural network and extreme gradient boost models demonstrated the next best results (0.776 [0.735–0.818]). The AUC of the random forest model was higher than 0.611 (0.583–0.640), 0.677 (0.651–0.703), and 0.722 (0.677–0.767), as achieved by APACHE II, SOFA, and MOSAIC, respectively. The machine learning models also predicted in-hospital mortality better than APACHE II, SOFA, and MOSAIC.

Conclusion

Machine learning algorithms increase the accuracy of mortality prediction for patients undergoing CRRT for acute kidney injury compared with previous scoring models.

Analysis of survival after initiation of continuous renal replacement therapy in patients with extracorporeal membrane oxygenation

Background

No study has specifically investigated the duration of continuous renal replacement therapy (CRRT) in patients who experienced acute kidney injury during extracorporeal membrane oxygenation (ECMO) support. However, there are concerns that prolonged CRRT may be futile.

Methods

We conducted a retrospective population-based cohort study using Taiwan National Health Insurance Research Database data collected between January 1, 2007 and December 31, 2013. Patients who received ECMO and CRRT during the study period were included. We divided patients into three groups based on the duration of CRRT received: ≤ 3 days, 4–6 days, and ≥ 7 days. The outcomes were all-cause mortality, end-stage renal disease, ventilator dependency, and readmission rate.

Results

There were 247, 134 and 187 patients who survived the hospitalization in the CRRT for ≤3 days, 4–6 days and > 7 days respectively. Survival after discharge did not differ significantly between CRRT for 4–6 days vs. ≤ 3 days (adjusted hazard ratio [aHR] 1.16, 95% confidence interval [CI] 0.85–1.57), between CRRT for > 7 days vs. ≤ 3 days (aHR 1.001, 95% CI 0.73–1.38) and between CRRT for > 7 days vs. 4–6 days (aHR 0.87, 95% CI 0.62–1.22). The patients who received CRRT for ≥7 days had a higher risk of ESRD than did those who received CRRT for ≤3 days (adjusted hazard ratio [aHR] 3.46, 95% confidence interval [CI] 1.47–8.14) and for 4–6 days (aHR 3.10, 95% CI 1.03–9.29). The incidence of ventilator dependence was higher in the patients with CRRT ≥7 days than in those with ≤3 days (aHR 2.45, 95% CI 1.32–4.54). The CRRT ≥7 days group also exhibited a higher readmission rate than did the 4–6 days and ≤ 3 days groups (aHR 1.43, 95% CI 1.04–1.96 and aHR 1.67, 95% CI 1.13–2.47, respectively).

Conclusions

Our study found similar long-term survival but increased ESRD and ventilator dependency among ECMO patients who underwent CRRT for ≥7 days. These results offer reason to be concerned that this aggressive life support may maintain patient survival but do so at the cost of long-term disabilities and a lower quality of life.

Electronic supplementary material

The online version of this article (10.1186/s12882-019-1516-6) contains supplementary material, which is available to authorized users.

Oxygen delivery to the blood stream by the dialysis fluid during continuous renal replacement therapy ex vivo

Continuous renal replacement therapy (CRRT) maintains a balance in body water and electrolytes. CRRT supplies a higher quantity of fluid than intravenous fluid therapy along with simultaneous fluid withdrawal. We hypothesized that use of a high-oxygen-containing solution for high-volume fluid exchange would improve oxygenation in the blood during CRRT. To start with, we prepared a solution containing high oxygen. The objective of this study was to determine if this solution would increase the partial pressure of oxygen (pO₂) in the blood more than that using a conventional solution during CRRT. We compared the gas profile of the experimental fluid ex vivo in a simulated CRRT for 24 h, using 2-L batches of bovine blood. A significant increase in the pO₂, pH, and total oxygen delivery, and a significant decrease in the partial pressure of carbon dioxide (pCO₂) were estimated in the bovine blood using the experimental solution during the simulated CRRT. This method is simpler to apply for oxygenation than the conventional method, and will be beneficial to hypoxic patients in terms of improving their blood oxygenation during CRRT.

Factors Associated with Early Mortality in Critically Ill Patients Following the Initiation of Continuous Renal Replacement Therapy

Continuous renal replacement therapy (CRRT) is an important modality to support critically ill patients, and the need for CRRT treatment has been increasing. However, CRRT management is costly, and the associated resources are limited. Thus, it remains challenging to identify patients that are likely to have a poor outcome, despite active treatment with CRRT. We sought to elucidate the factors associated with early mortality after CRRT initiation. We analyzed 240 patients who initiated CRRT at an academic medical center between September 2016 and January 2018. We compared baseline characteristics between patients who died within seven days of initiating CRRT (early mortality), and those that survived more than seven days beyond the initiation of CRRT. Of the patients assessed, 130 (54.2%) died within seven days of CRRT initiation. Multivariate logistic regression models revealed that low mean arterial pressure, low arterial pH, and high Sequential Organ Failure Assessment score before CRRT initiation were significantly associated with increased early mortality in patients requiring CRRT. In conclusion, the mortality within seven days following CRRT initiation was very high in this study. We identified several factors that are associated with early mortality in patients undergoing CRRT, which may be useful in predicting early outcomes, despite active treatment with CRRT.

Analysis of Survival After Initiation of Continuous Renal Replacement Therapy in a Surgical Intensive Care Unit

IMPORTANCE

Continuous renal replacement therapy (CRRT) benefits patients with renal failure who are too hemodynamically unstable for intermittent hemodialysis. The duration of therapy beyond which continued use is futile, particularly in a population of patients admitted to and primarily cared for by a surgical service (hereinafter referred to as surgical patients), is unclear.

OBJECTIVE

To analyze proportions of and independent risk factors for survival to discharge after initiation of CRRT among patients in a surgical intensive care unit (SICU).

DESIGN, SETTING, AND PARTICIPANTS

This retrospective cohort study included all patients undergoing CRRT from July 1, 2012, through January 31, 2016, in an SICU of an urban tertiary medical center. The population included patients treated before or after general surgery and patients admitted to a surgical service during inpatient evaluation and care before liver transplant. The pretransplant population was censored from further survival analysis on receipt of a transplant.

EXPOSURES

Continuous renal replacement therapy.

MAIN OUTCOMES AND MEASURES

Hospital mortality among patients in an SICU after initiation of CRRT.

RESULTS

Of 108 patients (64 men [59.3%] and 44 women [40.7%]; mean [SD] age, 62.0 [12.7] years) admitted to the SICU, 53 were in the general surgical group and 55 in the pretransplant group. Thirteen of the 22 patients in the pretransplant group who required 7 or more days of CRRT died (in-hospital mortality, 59.1%); among the 12 patients in the general surgery group who required 7 or more days of CRRT, 12 died (in-hospital mortality, 100%). In the general surgical group, each day of CRRT was associated with an increased adjusted odds ratio of death of 1.39 (95% CI, 1.01-1.90; P = .04).

CONCLUSIONS AND RELEVANCE

Continuous renal replacement therapy is valuable for surgical patients with an acute and correctable indication; however, survival decreases significantly with increasing duration of CRRT. Duration of CRRT does not correlate with survival among patients awaiting liver transplant.

Heart rate is associated with mortality in patients undergoing continuous renal replacement therapy

BACKGROUND

Heart rate (HR) is an essential vital sign based on the finding that HR beyond its normal range is associated with several conditions or diseases, including high mortality in several clinical settings. Nevertheless, the clinical implications of HR remain unresolved in patients undergoing continuous renal replacement therapy (CRRT).

METHODS

This retrospective cohort study included 828 patients who underwent CRRT due to acute kidney injury between 2010 and 2014. HR and other baseline parameters at the time of CRRT initiation were retrieved. The odds ratio (OR) of 30-day mortality was calculated using a multivariate logistic model.

RESULTS

CRRT significantly lowered the HR of patients such that the pre- and post-CRRT HRs (average 6 hours) were 107 beats/min and 103 beats/min, respectively (P < 0.001). When we explored the relationship with 30-day mortality, only HR at the time of CRRT initiation, but not pre- or post-CRRT HR, had a significant relationship with mortality outcome. Based on this result, we divided patients into quartiles of HR at the time of CRRT initiation. Mortality OR in the 4th quartile HR group was 2.6 (1.78-3.92) compared with the 1st quartile HR group. This relationship remained consistent despite adjusting for 28 baseline covariates: OR, 1.7 (1.09-2.76); P = 0.020. However, HR was not associated with the weaning rate from CRRT.

CONCLUSION

High HR at the time of CRRT initiation is subsequently related with high mortality. These results can be a basis for a future predictive model of CRRT-related mortality.