Survival by Dialysis Modality in Critically Ill Patients with Acute Kidney Injury

Critical illness myopathy and trajectory of recovery in acute kidney injury requiring continuous renal replacement therapy: a prospective observational trial protocol

INTRODUCTION

Acute kidney injury requiring renal replacement therapy (AKI-RRT) is common in the intensive care unit (ICU) and is associated with significant morbidity and mortality. Continuous RRT (CRRT) non-selectively removes large amounts of amino acids from plasma, lowering serum amino acid concentrations and potentially depleting total-body amino acid stores. Therefore, the morbidity and mortality associated with AKI-RRT may be partly mediated through accelerated skeletal muscle atrophy and resulting muscle weakness. However, the impact of AKI-RRT on skeletal muscle mass and function during and following critical illness remains unknown. We hypothesise that patients with AKI-RRT have higher degrees of acute muscle loss than patients without AKI-RRT and that AKI-RRT survivors are less likely to recover muscle mass and function when compared with other ICU survivors.

METHODS AND ANALYSIS

This protocol describes a prospective, multicentre, observational trial assessing skeletal muscle size, quality and function in ICU patients with AKI-RRT. We will perform musculoskeletal ultrasound to longitudinally evaluate rectus femoris size and quality at baseline (within 48 hours of CRRT initiation), day 3, day 7 or at ICU discharge, at hospital discharge, and 1-3 months postdischarge. Additional skeletal muscle and physical function tests will be performed at hospital discharge and postdischarge follow-up. We will analyse the effect of AKI-RRT by comparing the findings in enrolled subjects to historical controls of critically ill patients without AKI-RRT using multivariable modelling.

ETHICS AND DISSEMINATION

We anticipate our study will reveal that AKI-RRT is associated with greater degrees of muscle loss and dysfunction along with impaired postdischarge recovery of physical function. These findings could impact the in-hospital and postdischarge treatment plan for these patients to include focused attention on muscle strength and function. We intend to disseminate findings to participants, healthcare professionals, the public and other relevant groups via conference presentation and publication without any publication restrictions.

TRIAL REGISTRATION NUMBER

NCT05287204.

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.

Renal Replacement Therapy in Patients with Influenza Pneumonia Related Acute Respiratory Distress Syndrome

Acute kidney injury (AKI) requiring renal replacement therapy (RRT) increases the mortality of acute respiratory distress syndrome (ARDS) patients. The aim of this study was to investigate the outcomes and predictors of RRT in patients with influenza pneumonia-related ARDS. This retrospective cohort study includes patients from eight tertiary referral centers in Taiwan between January and March 2016, and all 282 patients with influenza pneumonia-related ARDS were enrolled. Thirty-four patients suffered from AKI requiring RRT, while 16 patients had underlying end stage renal disease (ESRD). The 30- and 60-day mortality rates were significantly higher in patients with AKI requiring RRT compared with those not requiring RRT (50.0% vs. 19.8%, p value < 0.001; 58.8% vs. 27.2%, p value = 0.001, respectively), but the patients with ESRD had no significant difference in mortality (12.5% vs. 19.8%, p value = 0.744; 31.3% vs. 27.2%, p value = 0.773, respectively). The predictors for AKI requiring RRT included underlying chronic liver disease and C-reactive protein. The mortality predictors for patients with AKI requiring RRT included the pneumonia severity index, tidal volume, and continuous renal replacement therapy. In this study, patients with influenza pneumonia-related ARDS with AKI requiring RRT had significantly higher mortality compared with other patients.

Is Early Monitoring Better? Impact of Early Vancomycin Exposure on Treatment Outcomes and Nephrotoxicity in Patients with Methicillin-Resistant Staphylococcus aureus Infections

Optimal early vancomycin target exposure remains controversial. To clarify the therapeutic exposure range, we investigated the association between vancomycin exposure and treatment outcomes or nephrotoxicity in patients with methicillin-resistant Staphylococcus aureus (MRSA) infection. This retrospective study reviewed clinical data obtained from 131 patients with MRSA infections between January 2017 and September 2019. Clinical outcomes included treatment failure, 30-day mortality, microbiological failure, and acute kidney injury. We measured serum vancomycin levels after the first dose to 48 h and estimated vancomycin exposure using the Bayesian theorem. The minimum inhibitory concentration (MIC) of antimicrobial agents was determined using the broth microdilution method. Classification and Regression Tree analyses identified day 1 and 2 exposure thresholds associated with an increased risk of failure and nephrotoxicity. Treatment failure (27.9% vs. 33.3%) and 30-day mortality (26.6% vs. 31.74%) were numerically but not significantly reduced in patients with the area under the curve (AUC)_24-48h/MIC_BMD ≥ 698. Patients with AUC_ss/MIC_BMD ≥ 679 exhibited a significantly increased risk of acute kidney injury (27.9% vs. 10.9%, p = 0.041). These findings indicate that AUC_ss/MIC_BMD ratios > 600 may cause nephrotoxicity. AUC/MIC_BMD at days 1 and 2 do not appear to be significantly associated with particular clinical outcomes, but further studies are needed.

Use of matching methods in observational studies with critical patients and renal outcomes. Scoping review

Introduction: The use of matching techniques in observational studies has been increasing and is not always used appropriately. Clinical experiments are not always feasible in critical patients with renal outcomes, and observational studies are an important alternative. Objective: Through a scoping review, determine the available evidence on the use of matching methods in studies involving critically ill patients and assessing renal outcomes. Methods: Medline, Embase, and Cochrane databases were used to identify articles published between 1992 and 2020 up to week 10, which studied different exposures in the critically ill patient with renal outcomes and used propensity matching methods. Results: Most publications are cohort studies 94 (94. 9 %), five studies (5. 1 %) were cross-sectional. The main pharmacological intervention was the use of antibiotics in seven studies (7. 1%) and the main risk factor studied was renal injury prior to ICU admission in 10 studies (10. 1%). The balance between the baseline characteristics assessed by standardized means, in only 28 studies (28. 2%). Most studies 95 (96 %) used logistic regression to calculate the propensity index. Conclusion: Major inconsistencies were observed in the use of methods and in the reporting of findings. A summary is made of the aspects to be considered in the use of the methods and reporting of the findings with the matching by propensity index.

Optimal timing of initiating continuous renal replacement therapy in septic shock patients with acute kidney injury

Acute kidney injury (AKI) in patients with septic shock is associated with high mortality, but the appropriate timing for initiating continuous renal replacement therapy (CRRT) is controversial. We retrospectively enrolled 158 septic shock patients with AKI in the medical intensive care unit (ICU) from July 2016 to April 2018. The time from AKI onset to CRRT initiation was compared according to ICU mortality using Cox proportional hazard, receiver operating characteristic, and Kaplan-Meier survival analyses. At the time of ICU discharge, the mortality rate was 50.6% (n = 80). It took longer to initiate CRRT in non-survivors than in survivors (hazard ratio 1.009; 95% confidence interval [CI] 1.003–1.014; P = 0.002). The cut-off time from AKI onset to CRRT initiation for ICU mortality was 16.5 hours (area under the curve 0.786; 95% CI 0.716–0.856; P < 0.001). The cumulative mortality rate was significantly higher in patients in whom CRRT was initiated beyond 16.5 hours after AKI onset than in those in whom CCRT was initiated within 16.5 hours (log-rank test, P < 0.001). Several clinical situations must be considered to determine the optimal timing of CRRT initiation in these patients. Close observation and CRRT initiation within 16.5 hours after AKI onset may help improve survival.

A Propensity Score-adjusted Analysis of the Effects of Ubiquitin E3 Ligase Copy Number Variation in Peripheral Blood Leukocytes on Colorectal Cancer Risk

Background: The ubiquitin ligases E3 (E3s) plays a key role in the specific protein degradation in many carcinogenic biological processes. Colorectal cancer (CRC) development may be affected by the copy number variation (CNV) of E3s. Prior studies may have underestimated the impact of potential confounding factors' effects on the association between gene CNV and CRC risk, and CRC risk predictive model integrating gene CNV patterns is lacking. Our research sought to assess the genes CNVs of MDM2, SKP2, FBXW7, β-TRCP, and NEDD4-1 and CRC risk by using propensity score (PS) adjustment and developing models that integrate CNV patterns for CRC risk predictions.

Methods: This study comprising 1036 participants used traditional regression and different PS techniques to adjust the confounding factors to evaluate the relationships between five gene CNVs and CRC risk, and to establish a CRC risk predictive model. The AUC was applied to evaluate the effect of the model. The categorical net reclassification improvement (NRI) and the integrated discrimination improvement (IDI) were analyzed to evaluate the discriminatory accuracy improvement among the models.

Results: Compared to variable adjustment, the odds ratios (ORs) tended to be conservative and accurate with narrow confidence intervals (CIs) after PS adjustment. After PS adjustment, MDM2 amplification was related to increased CRC risk (Amp-pattern: OR = 8.684, 95% CI: 1.213-62.155, P = 0.031), whereas SKP2 deletion and the (del+amp) genotype were associated with reduced CRC risk (Del-pattern: OR = 0.323, 95% CI: 0.106-0.979, P = 0.046; Var-pattern: OR = 0.339, 95% CI: 0.135-0.854, P = 0.024). The predictive model integrating the gene CNV pattern could correctly reclassify 1.7% of the subjects.

Conclusions: MDM2 amplification and SKP2 CNVs are associated with increased and decreased CRC risk, respectively; abnormal CNV-integrated model is more precise for predicting CRC risk. Further studies are needed to verify these encouraging outcomes.

The relationship and threshold of serum phosphate with regard to the 28-day mortality risk in sepsis patients undergoing continuous renal replacement therapy

Objective

To investigate the association between serum phosphate levels and the risk of 28-day mortality in critically-ill patients with septic acute kidney injury (AKI) undergoing continuous renal replacement therapy (CRRT).

Methods

This retrospective cohort study analysed data from critically-ill patients with septic AKI who underwent CRRT between January 2009 and September 2016. Demographic, clinical and routine biochemical data were retrieved from a database and analysed to identify risk factors for 28-day mortality.

Results

A total of 796 patients were included in the analyses. Multivariate regression analyses showed that phosphate (0 h), phosphate (24 h) and delta phosphate were associated with the 28-day mortality in patients with septic AKI undergoing CRRT. The adjusted odds ratios (95% confidence interval) were 1.12 (1.03, 1.22), 1.22 (1.14, 1.30) and 1.12 (1.04, 1.20) for phosphate (0 h), phosphate (24 h) and delta phosphate, respectively. Curve fitting and threshold analyses showed that when phosphate (0 h) was between 5.6 mg/dl and 8.7 mg/dl, phosphate (24 h) was >3.8 mg/dl and delta phosphate was >–1, the 28-day mortality risk increased significantly.

Conclusion

In patients with septic AKI undergoing CRRT, serum phosphate level was associated with the prognosis of patients in terms of 28-day mortality.

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.

Impact of Dialysis Requirement in Community-acquired Pneumonia Hospitalizations

Background

Community-acquired pneumonia (CAP) is a common cause of hospitalization. While there are single-center studies on acute kidney injury requiring dialysis (AKI-D) and CAP, data on national trends and outcomes regarding AKI-D in CAP hospitalizations is lacking.

Methods

We utilized the Nationwide Inpatient Sample to analyze trends overall and within subgroups. We also utilized multivariate regression to adjust for potential confounders of annual trends and to generate adjusted odds ratios (aOR) for predictors and outcomes, including mortality and adverse discharge.

Results

There were 11,500,456 pneumonia hospitalizations between 2002 and 2013, of which 3675 (0.3%) were complicated by AKI-D. The AKI-D rate increased from 2.7/1000 hospitalizations in 2002 to 4.3/1000 hospitalizations in 2013. The rate of increase was higher in males and African Americans. Although temporal changes in demographics and comorbidities explained a substantial proportion, they could not explain the entire trend. The predictor with the highest odds of AKI-D required mechanical ventilation during hospitalization (aOR 12.47; 95% CI 11.66-13.34). Other significant predictors included sepsis (aOR 4.37; 95% CI 4.09-4.66), heart failure (aOR 2.40; 95% CI 2.25-2.55), and chronic kidney disease (CKD) (aOR 2.00; 95% CI 1.86-2.16). AKI-D was associated with increased in-hospital mortality (aOR 3.08; 95% CI 2.88-3.30) and adverse discharge (aOR 2.09; 95% CI 1.92-2.26). Although adjusted mortality decreased per year, attributable mortality remained stable.

Conclusion

Pneumonia hospitalizations complicated by AKI-D have increased with a differential increase by demographic groups. AKI-D is associated with significant morbidity and mortality. In the absence of effective AKI-D therapies, the focus should be on early risk stratification and prevention to avoid this devastating complication.

Renal Replacement Therapy for Acute Kidney Injury: Let's follow the Evidence

Selection of a dialysis modality for critically ill patients with acute kidney injury (AKI) continues to be a controversial topic. Available studies can be divided into: 1) randomized controlled trials assessing the effect of treatment dose on patient outcome; 2) randomized controlled outcome comparisons of CRRT and IRRT; and 3) observational outcome comparisons of CRRT and IRRT Clinical outcome comparisons of CRRT and HD continue to be very problematic. With the availability of the recent CRRT dose/outcome data, the interpretation of CRRT vs HD trial data now becomes nearly impossible because of the low-dose “handicap” that has existed in all of the comparative trials in the CRRT arms. Randomized and observational outcome studies suffer from several methodological problems and a final statement cannot be made. In the end, CRRT and HD are vastly different therapies that are not mutually exclusive but rather are complementary - they provide different options for patients at variable stages of their AKI course. Very preliminary data from SLED studies suggest this therapy also can be part of the continuum of AKI dialytic modalities. However, the lack of any meaningful outcome data for this therapy invalidates any claims of clinical “equivalence” to the other established modalities.

Patient and Kidney Survival by Dialysis Modality in Critically Ill Patients with Acute Kidney Injury

Using a large, international cohort, we sought to determine the effect of initial technique of renal replacement therapy (RRT) on the outcome of acute renal failure (ARF) in the intensive care unit (ICU). We enrolled 1218 patients treated with continuous RRT (CRRT) or intermittent RRT (IRRT) for ARF in 54 ICUs in 23 countries. We obtained demographic, biochemical and clinical data and followed patients to either death or hospital discharge. Information was analyzed to assess the independent impact of treatment choice on survival and renal recovery. Patients treated first with CRRT (N=1006, 82.6%) required vasopressor drugs and mechanical ventilation more frequently compared to those receiving IRRT (N=212, 17.4%), (p<0.0001). Unadjusted hospital survival was lower (35.8% vs. 51.9%, p<0.0001). However, unadjusted dialysis-independence at hospital discharge was higher after CRRT (85.5% vs. 66.2%, p<0.0001). Multivariable logistic regression showed that choice of CRRT was not an independent predictor of hospital survival or dialysis-free hospital survival. However, the choice of CRRT was a predictor of dialysis independence at hospital discharge among survivors (OR: 3.333, 95% CI: 1.845 - 6.024, p<0.0001). Further adjustment using a propensity score did not significantly change these results. We conclude that worldwide, the choice of CRRT as initial therapy is not a predictor of hospital survival or dialysis-free hospital survival but is an independent predictor of renal recovery among survivors.

Systematic review and meta-analysis of renal replacement therapy modalities for acute kidney injury in the intensive care unit

PURPOSE

To compare clinical outcomes among critically ill adults with acute kidney injury (AKI) treated with continuous renal replacement therapy (CRRT), intermittent hemodialysis (IHD) or sustained low efficiency dialysis (SLED).

MATERIALS AND METHODS

We completed a systematic review and meta-analysis of studies published in 2015 or earlier using MEDLINE®, EMBASE®, Cochrane databases and grey literature. Eligible studies included randomized clinical trials (RCTs) or prospective cohort studies comparing outcomes of mortality, dialysis dependence or length of stay among critically ill adults receiving CRRT, IHD or SLED to treat AKI. Mortality and dialysis dependence from RCTs were pooled using meta-analytic techniques. Length of stay from RCTs and results from prospective cohort studies were described qualitatively.

RESULTS

Twenty-one studies were eligible. RRT modality was not associated with in-hospital mortality (CRRT vs IHD: RR 1.00 [95% CI, 0.92-1.09], CRRT vs SLED: RR 1.23 [95% CI, 1.00-1.51]) or dialysis dependence (CRRT vs IHD: RR 0.90 [95% CI, 0.59-1.38], CRRT vs SLED: RR 1.15 [95% CI, 0.67-1.99]).

CONCLUSIONS

We did not find a definitive advantage for any RRT modality on short-term patient or kidney survival. Well-designed, adequately-powered trials are needed to better define the role of RRT modalities for treatment of critically ill patients with AKI.

Efficacy and outcomes of continuous peritoneal dialysis versus daily intermittent hemodialysis in pediatric acute kidney injury

BACKGROUND

Acute kidney injury (AKI) requiring renal replacement therapy (RRT) is associated with high patient morbidity and mortality. There is no consensus on the best RRT modality for pediatric AKI.

METHODS

The efficacy and safety of continuous peritoneal dialysis (cPD) and daily intermittent hemodialysis (dHD) were compared in 136 children aged 1 month to 16 years requiring RRT for AKI. Mortality, risk factors and causes of death, 1-month and 3-month renal recovery rates, and technique-related complications were assessed.

RESULTS

Uremia control and the rate of catheter-related complications were comparable in the groups. Thirty-day survival was 60.7 % (51 out of 84) with cPD and 36.5 % (19 out of 52) with dHD (p = 0.019). Although age <1 year, extended time lag from disease onset to RRT initiation, mechanical ventilation, and extended vasopressor dependence independently predicted death, adjusted mortality was higher with dHD relative to cPD (hazard ratio [HR] 1.75, 95%CI 1.18-2.84, p = 0.022). Almost all fatalities in the dHD group (94 %) occurred during or within an hour of a HD session. Renal function normalized in 27 % of survivors after 4 weeks and in 51 % after 3 months. The risk of permanent end-stage renal disease was increased in patients with an intrinsic renal cause of AKI (HR 2.72; 95 % CI 1.37-3.83; p = 0.029) and in those with delayed RRT initiation (HR 2.17; 95 % CI 123-2.93; p = 0.015), but did not differ between patients treated with dHD and cPD.

CONCLUSIONS

Favorable patient survival with cPD compared with dHD in children treated for AKI was evident in this study.

Potential Survival Benefit of Polymyxin B Hemoperfusion in Septic Shock Patients on Continuous Renal Replacement Therapy: A Propensity-Matched Analysis

BACKGROUND/AIMS

We assessed the survival benefit of polymyxin B hemoperfusion (PMX) in septic shock patients starting continuous renal replacement therapy (CRRT), who are known to have an increased rate of mortality.

METHODS

Adult patients in the Japanese diagnosis procedure combination database satisfying the following criteria were enrolled: hospitalized in 2007-2012; diagnosed as having sepsis; required noradrenaline and/or dopamine; and started CRRT in intensive care unit. Propensity scores for receiving PMX were created from patient and hospital characteristics.

RESULTS

Of 3,759 eligible patients, 1,068 received PMX. Propensity-score matching produced a matched cohort of 978 pairs. The 28-day mortality was 40.2% (393/978) in the PMX group and 46.8% (458/978) in the control group (p = 0.003). Logistic regression analysis revealed a significant association between the use of PMX and decreased 28-day mortality (adjusted OR 0.75; 95% CI 0.62-0.91).

CONCLUSION

This large retrospective study suggests that septic shock patients starting CRRT may benefit from PMX.

Current state of continuous renal replacement therapy for acute kidney injury in Japanese intensive care units in 2011: analysis of a national administrative database

BACKGROUND

Nationwide data for the prevalence and outcomes of patients receiving continuous renal replacement therapy (CRRT) in intensive care units (ICUs) are scarce. This study assessed the status of CRRT in Japanese ICUs using a nationwide administrative claim database.

METHODS

Data were extracted from the Japanese Diagnosis Procedure Combination database for 2011. From a cohort of critically ill patients aged 12 years or older who were admitted to ICUs for 3 days or longer, acute kidney injury (AKI) patients treated with CRRT were identified. The period prevalence of CRRT and in-hospital mortality were calculated. Logistic regression analysis identified factors associated with in-hospital mortality.

RESULTS

Of 165 815 ICU patients, 6478 (3.9%) received CRRT for AKI. The most frequent admission diagnosis category was diseases of the circulatory system (n = 3074). The overall in-hospital mortality rate of the CRRT-treated AKI patients was 50.6%. Clustering patients into four groups by background revealed the lowest in-hospital mortality rate of 41.5% for the cardiovascular surgery group (n = 1043) compared with 53.5% for the nonsurgical cardiovascular group (n = 2031), 51.7% for the sepsis group (n = 1863) and 51.6% for other cases (n = 1541). Multiple logistic regression analysis showed a significant association of these four group classifications with in-hospital mortality in addition to age, hospital characteristics (type and volume), time from hospital admission to CRRT initiation and interventions performed on the day of CRRT initiation.

CONCLUSIONS

Using a large Japanese nationwide database, this study revealed remarkably high in-hospital mortality of CRRT-treated AKI patients, although the period prevalence of CRRT for AKI in ICUs was low.

TNF-α depuration is a predictor of mortality in critically ill patients under continuous veno-venous hemodiafiltration treatment

INTRODUCTION

Critically ill patients with acute kidney injury (AKI) present high mortality rates. The magnitude of inflammatory response could determine the prognosis of such patients. Continuous renal replacement therapy (CRRT) may play an important role in removing inflammatory mediators in patients with AKI.

AIM

To investigate whether the magnitude of inflammatory mediator's removal is associated with mortality among critically ill patients on CVVHDF, a CRRT modality.

METHODS

This study consisted of 64 critically ill patients requiring CVVHDF. Plasma levels of C3a, TNF-α, IL-10, IL-6, IL-1β, sTNFRI and sTNFRII were determined by enzyme-linked immunosorbent assay (ELISA) at the beginning of CVVHDF and after 24h (outlet). Clearance of cytokines during the first 24h of CVVHDF was calculated. Clinical and laboratory data were acquired from patient's records data.

RESULTS

Mean age of patients requiring CVVHDF was 63years, 67.2% were men and 87.3% were Caucasian. Thirty-five (35) patients (54.7%) died. Comparing non-survivors with the group of survivors we observed higher incidence of sepsis (68.6 versus 37.9%, p<0.05), higher APACHE II score (34.8±7.6 versus 29.2±7.1, p<0.05) and higher lactate levels (23.2±17.6 versus 16.4±6.6, p<0.05). According to the inter-tertile range of TNF-α clearance (ITR1 (<0.54); ITR2 (0.54-2.93); ITR3 (>2.93)) we found that those patients with higher TNF-α removal by RRT (ITR3) had a better survival. Multivariable analysis showed that lower clearance of TNF-α remained independently associated with high mortality after adjustment for sex, age, use of vasoactive drugs, APACHE II score sepsis, creatinine and lactate before CVVHDF (HR: 0.179, 95% IC: 0.049-0.661, p<0.01).

CONCLUSION

The attenuation of inflammatory response may be related to the lower mortality observed on those patients with higher TNF-α removal by CVVHDF.

The analysis on risk factors and clinical treatment of craniocerebral injury concurrent with acute kidney injury

The main objective of this study was to investigate the risk factors and clinical treatment of craniocerebral injury concurrent with acute kidney injury. A total of 220 patients who suffered from craniocerebral injury from March 2010 to March 2012 in our Hospital were prospectively analyzed. Craniocerebral injury was defined according to the medical history, the verification of CT, and some investigated scores. The acute kidney injury was defined as a relative 47% increase of serum creatinine. The method of multivariate logistic regression analysis was used to evaluate the possible risk factors associated with post-craniocerebral injury concurrent with acute kidney injury. The clinical treatments of craniocerebral injury concurrent with acute kidney injury were also identified via experimental results, and the pathological mechanism of craniocerebral injury concurrent with acute kidney injury was found to be related to cerebral tissue lesions, but some potential factors were ambiguous. The incidence of acute kidney injury was 70.2% with craniocerebral injury. In hospital, mortality of acute kidney injury patients was 31.2%, which was 6.019 times of non-acute kidney injury patients (p < 0.01). The incidence of acute kidney injury in patients with craniocerebral injury was 58.3%, which was significantly higher compared to moderate and mild groups (p < 0.01). Unconditional multivariate logistic regression analysis results revealed that lower score, elderly, and male were the independent predictors of acute kidney injury episodes. Finally, some important factors were worthy of detailed study and further investigation.

Choice of renal replacement therapy modality in intensive care units: data from a Japanese Nationwide Administrative Claim Database

PURPOSE

This study was undertaken to assess recent trends of the choice of renal replacement therapy (RRT) modalities in Japanese intensive care units (ICUs).

MATERIALS AND METHODS

Data were extracted from the Japanese Diagnosis Procedure Combination database for 2011. We identified adult patients without end-stage renal disease who had been admitted to ICUs for 3 days or longer and started continuous RRT (CRRT) or intermittent RRT (IRRT). Logistic regression was used to analyze which factors affected the modality choice. We further evaluated in-hospital mortality according to the choice of RRT.

RESULTS

Of 7353 eligible patients, 5854 (79.6%) initially received CRRT. The choice of CRRT was independently associated with sex (female), diagnosis of sepsis, hospital type (academic) and volume, vasoactive agents, mechanical ventilation, colloid administration, blood transfusion, intra-aortic balloon pumping, and venoarterial extracorporeal membrane oxygenation. Particularly, the number of vasoactive drugs was strongly associated with the CRRT choice. Overall in-hospital mortality in the CRRT group was higher than that in the IRRT group (50.0% vs 31.1%) and was increased when IRRT was switched to CRRT (59.1%).

CONCLUSIONS

Continuous RRT is apparently preferred in actual ICU practice, especially for hemodynamically unstable patients, and subsequent RRT modality switch is associated with mortality.

The growth of acute kidney injury: a rising tide or just closer attention to detail?

Acute kidney injury (AKI), previously termed acute renal failure, is associated with increased mortality, prolonged hospital stay, and accelerated chronic kidney disease (CKD). Over the past 2 decades, dramatic rises in the incidences of AKI have been reported, particularly within the United States. The question arises as to whether these changes reflect actual increases in disease incidence, or are potentially explained by the introduction of consensus definitions that rely on small standardized changes in serum creatinine, changes in coding and reimbursement, or increasingly available and more liberal use of dialysis. In this review, we explore the secular trends in AKI incidence in North America and Western Europe and its potential contributors.

Observational studies using propensity score analysis underestimated the effect sizes in critical care medicine

BACKGROUND AND OBJECTIVE

Propensity score (PS) analysis has been increasingly used in critical care medicine; however, its validation has not been systematically investigated. The present study aimed to compare effect sizes in PS-based observational studies vs. randomized controlled trials (RCTs) (or meta-analysis of RCTs).

METHODS

Critical care observational studies using PS were systematically searched in PubMed from inception to April 2013. Identified PS-based studies were matched to one or more RCTs in terms of population, intervention, comparison, and outcome. The effect sizes of experimental treatments were compared for PS-based studies vs. RCTs (or meta-analysis of RCTs) with sign test. Furthermore, ratio of odds ratio (ROR) was calculated from the interaction term of treatment × study type in a logistic regression model. A ROR < 1 indicates greater benefit for experimental treatment in RCTs compared with PS-based studies. RORs of each comparison were pooled by using meta-analytic approach with random-effects model.

RESULTS

A total of 20 PS-based studies were identified and matched to RCTs. Twelve of the 20 comparisons showed greater beneficial effect for experimental treatment in RCTs than that in PS-based studies (sign test P = 0.503). The difference was statistically significant in four comparisons. ROR can be calculated from 13 comparisons, of which four showed significantly greater beneficial effect for experimental treatment in RCTs. The pooled ROR was 0.71 (95% CI: 0.63, 0.79; P = 0.002), suggesting that RCTs (or meta-analysis of RCTs) were more likely to report beneficial effect for the experimental treatment than PS-based studies. The result remained unchanged in sensitivity analysis and meta-regression.

CONCLUSION

In critical care literature, PS-based observational study is likely to report less beneficial effect of experimental treatment compared with RCTs (or meta-analysis of RCTs).

Extracorporeal renal replacement therapy and blood purification in critical care

OBJECTIVE

To review indications methods of renal replacement therapies (RRT) and practical considerations for the creation of a RRT program.

DATA SOURCES

Current human and veterinary literature review with a focus on advanced renal physiology and clinical experience in RRT and acute/chronic kidney diseases.

DATA SYNTHESIS

Renal replacement therapies encompass intermittent hemodialysis, continuous renal replacement therapy as well as some "hybrid" techniques. Each method of RRT has practical and theoretical advantages but currently there is no evidence that one technique is superior to the other.

CONCLUSIONS

RRT is a valuable therapeutic tool for treatment of acute kidney injury and chronic kidney disease. The implementation of an RRT program needs to take into consideration multiple parameters beyond the choice of an RRT platform.

Renal replacement therapy in acute kidney injury

Although the use of renal replacement therapy (RRT) to support critically ill patients with acute kidney injury (AKI) has become routine, many of the fundamental questions regarding optimal management of RRT remain. This review summarizes current evidence regarding the timing of initiation of RRT, the selection of the specific modality of RRT, and prescription of the intensity of therapy. Although absolute indications for initiating RRT-such as hyperkalemia and overt uremic symptoms-are well recognized, the optimal timing of therapy in patients without these indications continues to be a subject of debate. There does not appear to be a difference in either mortality or recovery of kidney function associated with the various modalities of RRT. Finally, providing higher doses of RRT is not associated with improved clinical outcomes.

Treatment of critically ill children with kidney injury by sustained low-efficiency daily diafiltration

BACKGROUND

Continuous renal replacement therapy (CRRT) and intermittent hemodialysis (IHD) offer diverse benefits and drawbacks for critically ill children with acute kidney injury (AKI). Sustained low-efficiency daily diafiltration (SLEDD-f) involves a conceptual and technical hybrid of CRRT and IHD. We report our SLEDD-f application to critically ill children in the pediatric intensive care unit (PICU).

METHODS

SLEDD-f was delivered by the new Fresenius 5008 therapy system with blood flow 5 ml/kg/min, dialysate flow 260 ml/min, hemofiltration 35 ml/kg/h for 8-10 h daily. Changes in blood pressure, blood gas, electrolyte, hemoglobulin (Hb), and hematocrit (Hct) were closely monitored.

RESULTS

From February 2010 to June 2011, 14 critical patients with a total of 60 SLEDD-f sessions were studied retrospectively. Heparin was used in 46 sessions (76.6%) with no bleeding complications. Hypertension above 135 mmHg returned to normal, hypotension below 90 mmHg showed no drop. Metabolic acidosis and hyperkalemia normalized. Elevated Hb, Hct, and their ratio revealed improving hemodilution. Three episodes of intradialytic hypotension (5.0%) and one of circuit clotting (1.7%) led to premature termination. The 28-day survival rate was 71.4%.

CONCLUSIONS

This pilot investigation demonstrates that SLEDD-f provides good hemodynamic tolerance and correction of fluid overload, pH, and electrolyte imbalance for critically ill children with AKI.

Identification of candidate serum biomarkers for severe septic shock-associated kidney injury via microarray

Introduction

Septic-shock-associated acute kidney injury (SSAKI) carries high morbidity in the pediatric population. Effective treatment strategies are lacking, in part due to poor detection and prediction. There is a need to identify novel candidate biomarkers of SSAKI. The objective of our study was to determine whether microarray data from children with septic shock could be used to derive a panel of candidate biomarkers for predicting SSAKI.

Methods

A retrospective cohort study compared microarray data representing the first 24 hours of admission for 179 children with septic shock with those of 53 age-matched normal controls. SSAKI was defined as a >200% increase of baseline serum creatinine, persistent to 7 days after admission.

Results

Patients with SSAKI (n = 31) and patients without SSAKI (n = 148) were clinically similar, but SSAKI carried a higher mortality (45% vs. 10%). Twenty-one unique gene probes were upregulated in SSAKI patients versus patients without SSAKI. Using leave-one-out cross-validation and class prediction modeling, these probes predicted SSAKI with a sensitivity of 98% (95% confidence interval (CI) = 81 to 100) and a specificity of 80% (95% CI = 72 to 86). Serum protein levels of two specific genes showed high sensitivity for predicting SSAKI: matrix metalloproteinase-8 (89%, 95% CI = 64 to 98) and elastase-2 (83%, 95% CI = 58 to 96). Both biomarkers carried a negative predictive value of 95%. When applied to a validation cohort, although both biomarkers carried low specificity (matrix metalloproteinase-8: 41%, 95% CI = 28 to 50; and elastase-2: 49%, 95% CI = 36 to 62), they carried high sensitivity (100%, 95% CI = 68 to 100 for both).

Conclusions

Gene probes upregulated in critically ill pediatric patients with septic shock may allow for the identification of novel candidate serum biomarkers for SSAKI prediction.

Extracorporeal therapies in sepsis

The treatment of sepsis is an ongoing challenge for clinicians; despite the wide choice of effective antibiotics to treat infection, sepsis remains the leading cause of morbidity and mortality for patients admitted to an intensive care unit. Dysregulation of the immune response is now recognized to be a key factor in multiple organ dysfunction, yet our therapy for inflammation remains ineffective. It has been advocated for more than a decade that cytokine reduction in blood compartment could lead to a reduction in mortality in sepsis. Over the years, multiple extracorporeal techniques have evolved, with the intent of influencing the circulating levels of inflammatory mediators like cytokines and chemokines, the complement system, as well as factors of the coagulation system. These include high-volume hemofiltration, use of high cutoff membranes, and systems based on adsorption, such as coupled plasma filtration adsorption and the polymyxin-B column. In addition, new experimental systems that utilize human phagocytic cells and immobilized antibodies for targeted immunomodulation have emerged. In the context of limited resources and growing expansion in the availability of technologies, a better understanding of these therapies is required before they can be properly integrated into standard clinical practice in the hope of influencing major clinical outcomes. In this article, we will provide a concise overview of selected extracorporeal modalities currently in clinical use and briefly introduce some new promising techniques for sepsis.

Norepinephrine and hospital mortality in critically ill patients undergoing continuous renal replacement therapy

High-dose vasopressor use is associated with increasing mortality in patients with septic shock. We conducted this study to determine if the high-dose of vasopressor used before the initiation of continuous renal replacement therapy (CRRT) is associated with increasing mortality in critically ill patients. We retrospectively reviewed all patients who underwent CRRT in the medical intensive care unit of China Medical University Hospital between 2003 and 2007. The association between mortality and highest vasopressors (dopamine and norepinephrine [NE]) dose used were analyzed using Kaplan-Meier analysis and multivariate Cox regression. A total of 279 patients (170 men and 109 women) treated with CRRT in medical intensive care were reviewed and 237 (84.9%) died. In Kaplan-Meier analysis with log-rank test, dopamine dose of ≥20 µg/kg/min and NE dose of ≥0.3 µg/kg/min were significantly linked to mortality (P = 0.007 and <0.001). In multivariate Cox proportional hazards regression, NE dose of ≥0.3 µg/kg/min, Acute Physiology and Chronic Health Evaluation II score, and low platelet count were independently linked to mortality. The hazard ratios and 95% confidence interval (CI) were 1.771 (95% CI: 1.247-2.516, P = 0.001), 1.035 (95% CI: 1.012-1.058, P = 0.003), and 0.997 (95% CI: 0.996-0.999, P = 0.003), respectively. Critically ill patients treated with very high dose of NE before the initiation of CRRT have a very high mortality rate regardless of the acute kidney injury stage.

Taking the septic patient to the operating room

The acutely septic patient is a multifaceted challenge for the anesthetist. Unlike most elective surgery patients, acutely septic patients have severe systemic disease before the physiologic insults of anesthesia and surgery. The decision to operate is usually informed by the urgent or emergent need to correct a severe surgical problem and weighed against the higher risks of morbidity and mortality from the procedure itself. The care of the septic patient in the intensive care unit can help guide operating room management. However, the acuity and time course of intraoperative events, including hemorrhage and drug-induced shock states, compel the anesthetist to respond aggressively with therapies that may or may not be strongly substantiated with long-term data in the intensive care unit setting. The anesthesiologist must place considerations concerning short-term survival from the acute insult of surgery ahead of longer-term considerations.

An Official ATS/ERS/ESICM/SCCM/SRLF Statement: Prevention and Management of Acute Renal Failure in the ICU Patient: an international consensus conference in intensive care medicine

OBJECTIVES

To address the issues of Prevention and Management of Acute Renal Failure in the ICU Patient, using the format of an International Consensus Conference.

METHODS AND QUESTIONS

Five main questions formulated by scientific advisors were addressed by experts during a 2-day symposium and a Jury summarized the available evidence: (1) Identification and definition of acute kidney insufficiency (AKI), this terminology being selected by the Jury; (2) Prevention of AKI during routine ICU Care; (3) Prevention in specific diseases, including liver failure, lung Injury, cardiac surgery, tumor lysis syndrome, rhabdomyolysis and elevated intraabdominal pressure; (4) Management of AKI, including nutrition, anticoagulation, and dialysate composition; (5) Impact of renal replacement therapy on mortality and recovery.

RESULTS AND CONCLUSIONS

The Jury recommended the use of newly described definitions. AKI significantly contributes to the morbidity and mortality of critically ill patients, and adequate volume repletion is of major importance for its prevention, though correction of fluid deficit will not always prevent renal failure. Fluid resuscitation with crystalloids is effective and safe, and hyperoncotic solutions are not recommended because of their renal risk. Renal replacement therapy is a life-sustaining intervention that can provide a bridge to renal recovery; no method has proven to be superior, but careful management is essential for improving outcome.

An integrated clinical approach for the identification, prevention, and treatment of tumor lysis syndrome

Tumor lysis syndrome (TLS) is a potentially life-threatening metabolic disorder that occurs when tumor cells undergo rapid decomposition spontaneously or in response to cytoreductive therapy. Delayed recognition of the metabolic imbalances caused by the massive release of tumor cell contents may result in clinical complications such as acute kidney injury, seizures, and cardiac arrhythmias. Prevention, the key principle in TLS management, relies on the identification of patients at risk for developing TLS during chemotherapy or because of disease progression. TLS-related risk factors pertain to tumor type (particularly hematologic malignancies), specific tumor characteristics (e.g. bulky tumor, high cellular proliferation rate, sensitivity to cytoreductive therapy), and other host-related factors. A comprehensive grading system proposed by Cairo and Bishop classifies TLS syndromes into laboratory or clinical TLS, thus facilitating TLS prevention and management. The mainstays of TLS management include monitoring of electrolyte abnormalities, vigorous hydration, prophylactic antihyperuricemic therapy with allopurinol, and rasburicase treatment of patients at high TLS risk or with established hyperuricemia. Urine alkalinization and use of diuretics remain controversial clinical practices. In this review, we describe the incidence of, risk factors for, and diagnostic characteristics of TLS and summarize strategies for the prevention and management of TLS-associated metabolic abnormalities, particularly hyperuricemia. We specifically highlight recently published TLS management guidelines, which focus on the prevention of TLS and hyperuricemia based on a patient's level of risk, and the important role of nephrologists in the prevention and treatment of one of the most serious complications of TLS, acute kidney injury.

Incidence and outcomes of acute kidney injury in intensive care units: a Veterans Administration study

OBJECTIVES

: To examine the effect of severity of acute kidney injury or renal recovery on risk-adjusted mortality across different intensive care unit settings. Acute kidney injury in intensive care unit patients is associated with significant mortality.

DESIGN

: Retrospective observational study.

SETTING

: There were 325,395 of 617,927 consecutive admissions to all 191 Veterans Affairs ICUs across the country.

PATIENTS

: Large national cohort of patients admitted to Veterans Affairs ICUs and who developed acute kidney injury during their intensive care unit stay.

MEASUREMENTS AND MAIN RESULTS

: Outcome measures were hospital mortality, and length of stay. Acute kidney injury was defined as a 0.3-mg/dL increase in creatinine relative to intensive care unit admission and categorized into Stage I (0.3 mg/dL to <2 times increase), Stage II (> or =2 and <3 times increase), and Stage III (> or =3 times increase or dialysis requirement). Association of mortality and length of stay with acute kidney injury stages and renal recovery was examined. Overall, 22% (n = 71,486) of patients developed acute kidney injury (Stage I: 17.5%; Stage II: 2.4%; Stage III: 2%); 16.3% patients met acute kidney injury criteria within 48 hrs, with an additional 5.7% after 48 hrs of intensive care unit admission. Acute kidney injury frequency varied between 9% and 30% across intensive care unit admission diagnoses. After adjusting for severity of illness in a model that included urea and creatinine on admission, odds of death increased with increasing severity of acute kidney injury. Stage I odds ratio = 2.2 (95% confidence interval, 2.17-2.30); Stage II odds ratio = 6.1 (95% confidence interval, 5.74, 6.44); and Stage III odds ratio = 8.6 (95% confidence interval, 8.07-9.15). Acute kidney injury patients with sustained elevation of creatinine experienced higher mortality risk than those who recovered.

INTERVENTIONS

: None.

CONCLUSIONS

: Admission diagnosis and severity of illness influence frequency and severity of acute kidney injury. Small elevations in creatinine in the intensive care unit are associated with increased risk-adjusted mortality across all intensive care unit settings, whereas renal recovery was associated with a protective effect. Strategies to prevent even mild acute kidney injury or promote renal recovery may improve survival.

Treatment of acute renal failure in the intensive care unit: lower costs by intermittent dialysis than continuous venovenous hemodiafiltration

Intermittent and continuous renal replacement therapies (RRTs) are available for the treatment of acute renal failure (ARF) in the intensive care unit (ICU). Although at present there are no adequately powered survival studies, available data suggest that both methods are equal with respect to patient outcome. Therefore, cost comparison between techniques is important for selecting the modality. Expenditures were prospectively assessed as a secondary end point during a controlled, randomized trial comparing intermittent hemodialysis (IHD) with continuous venovenous hemodiafiltration (CVVHDF). The outcome of the primary end points of this trial, that is, ICU and in-hospital mortality, has been previously published. One hundred twenty-five patients from a Swiss university hospital ICU were randomized either to CVVHDF or IHD. Out of these, 42 (CVVHDF) and 34 (IHD) were available for cost analysis. Patients' characteristics, delivered dialysis dose, duration of stay in the ICU or hospital, mortality rates, and recovery of renal function were not different between the two groups. Detailed 24-h time and material consumption protocols were available for 369 (CVVHDF) and 195 (IHD) treatment days. The mean daily duration of CVVHDF was 19.5 +/- 3.2 h/day, resulting in total expenditures of Euro 436 +/- 21 (21% for human resources and 79% for technical devices). For IHD (mean 3.0 +/- 0.4 h/treatment), the costs were lower (Euro 268 +/- 26), with a larger proportion for human resources (45%). Nursing time spent for CVVHDF was 113 +/- 50 min, and 198 +/- 63 min per IHD treatment. Total costs for RRT in ICU patients with ARF were lower when treated with IHD than with CVVHDF, and have to be taken into account for the selection of the method of RRT in ARF on the ICU.

Acute kidney injury in the intensive care unit

Acute kidney injury (AKI) is common among critically ill patients and results in increased mortality in this population. This review focuses on the diagnosis and management of AKI. The authors first explore new aspects of diagnosis, including new criteria that take into account even modest changes in renal function, and the development of novel biomarkers to allow earlier identification and better differential diagnosis of AKI. The authors also explore the available data on choice of dialysis modality and dialysis dose for the treatment of AKI, as well as the breakthrough development of the bioartificial kidney. Last, the authors review co-interventions that may have relevance to prognosis of AKI, such as intensive insulin therapy and the use of erythropoietin.

Delivered dose of renal replacement therapy and mortality in critically ill patients with acute kidney injury

INTRODUCTION

The optimal dialysis dose for the treatment of acute kidney injury (AKI) is controversial. We sought to evaluate the relationship between renal replacement therapy (RRT) dose and outcome.

METHODS

We performed a prospective multicentre observational study in 30 intensive care units (ICUs) in eight countries from June 2005 to December 2007. Delivered RRT dose was calculated in patients treated exclusively with either continuous RRT (CRRT) or intermittent RRT (IRRT) during their ICU stay. Dose was categorised into more-intensive (CRRT >or= 35 ml/kg/hour, IRRT >or= 6 sessions/week) or less-intensive (CRRT < 35 ml/kg/hour, IRRT < 6 sessions/week). The main outcome measures were ICU mortality, ICU length of stay and duration of mechanical ventilation.

RESULTS

Of 15,200 critically ill patients admitted during the study period, 553 AKI patients were treated with RRT, including 338 who received CRRT only and 87 who received IRRT only. For CRRT, the median delivered dose was 27.1 ml/kg/hour (interquartile range (IQR) = 22.1 to 33.9). For IRRT, the median dose was 7 sessions/week (IQR = 5 to 7). Only 22% of CRRT patients and 64% of IRRT patients received a more-intensive dose. Crude ICU mortality among CRRT patients were 60.8% vs. 52.5% (more-intensive vs. less-intensive groups, respectively). In IRRT, this was 23.6 vs. 19.4%, respectively. On multivariable analysis, there was no significant association between RRT dose and ICU mortality (Odds ratio (OR) more-intensive vs. less-intensive: CRRT OR = 1.21, 95% confidence interval (CI) = 0.66 to 2.21; IRRT OR = 1.50, 95% CI = 0.48 to 4.67). Among survivors, shorter ICU stay and duration of mechanical ventilation were observed in the more-intensive RRT groups (more-intensive vs. less-intensive for all: CRRT (median): 15 (IQR = 8 to 26) vs. 19.5 (IQR = 12 to 33.5) ICU days, P = 0.063; 7 (IQR = 4 to 17) vs. 14 (IQR = 5 to 24) ventilation days, P = 0.031; IRRT: 8 (IQR = 5.5 to 14) vs. 18 (IQR = 13 to 35) ICU days, P = 0.008; 2.5 (IQR = 0 to 10) vs. 12 (IQR = 3 to 24) ventilation days, P = 0.026).

CONCLUSIONS

After adjustment for multiple variables, these data provide no evidence for a survival benefit afforded by higher dose RRT. However, more-intensive RRT was associated with a favourable effect on ICU stay and duration of mechanical ventilation among survivors. This result warrants further exploration.

TRIAL REGISTRATION

Cochrane Renal Group (CRG110600093).

Continuous Peritoneal Dialysis Compared with Daily Hemodialysis in Patients with Acute Kidney Injury

Background

In some parts of the world, peritoneal dialysis is widely used for renal replacement therapy (RRT) in acute kidney injury (AKI), despite concerns about its inadequacy. It has been replaced in recent years by hemodialysis and, most recently, by continuous venovenous therapies. We performed a prospective study to determine the effect of continuous peritoneal dialysis (CPD), as compared with daily hemodialysis (dHD), on survival among patients with AKI.

Methods

A total of 120 patients with acute tubular necrosis (ATN) were assigned to receive CPD or dHD in a tertiary-care university hospital. The primary endpoint was hospital survival rate; renal function recovery and metabolic, acid–base, and fluid controls were secondary endpoints.

Results

Of the 120 patients, 60 were treated with CPD (G1) and 60 with dHD (G2). The two groups were similar at the start of RRT with respect to age (64.2 ± 19.8 years vs 62.5 ± 21.2 years), sex (men: 72% vs 66%), sepsis (42% vs 47%), shock (61% vs 63%), severity of AKI [Acute Tubular Necrosis Individual Severity Score (ATNISS): 0.68 ± 0.2 vs 0.66 ± 0.22; Acute Physiology and Chronic Health Evaluation (APACHE) II: 26.9 ± 8.9 vs 24.1 ± 8.2], pre-dialysis blood urea nitrogen [BUN (116.4 ± 33.6 mg/dL vs 112.6 ± 36.8 mg/dL)], and creatinine (5.85 ± 1.9 mg/dL vs 5.95 ± 1.4 mg/dL). In G1, weekly delivered Kt/V was 3.59 ± 0.61, and in G2, it was 4.76 ± 0.65 ( p < 0.01). The two groups were similar in metabolic and acid–base control (after 4 sessions, BUN < 55 mg/dL: 46 ± 18.7 mg/dL vs 52 ± 18.2 mg/dL; pH: 7.41 vs 7.38; bicarbonate: 22.8 ± 8.9 mEq/L vs 22.2 ± 7.1 mEq/L). Duration of therapy was longer in G2 (5.5 days vs 7.5 days; p = 0.02). Despite the delivery of different dialysis methods and doses, the survival rate did not differ between the groups (58% in G1 vs 52% in G2), and recovery of renal function was similar (28% vs 26%).

Conclusion

High doses of CPD provided appropriate metabolic and pH control, with a rate of survival and recovery of renal function similar to that seen with dHD. Therefore, CPD can be considered an alternative to other forms of RRT in AKI.

Intermittent versus continuous renal replacement therapy for acute kidney injury patients admitted to the intensive care unit: results of a randomized clinical trial

BACKGROUND

There is uncertainty on the effect of different dialysis modalities for the treatment of patients with acute kidney injury (AKI), admitted to the intensive care unit (ICU). This controlled clinical trial performed in the framework of the multicentre SHARF 4 study (Stuivenberg Hospital Acute Renal Failure) aimed to investigate the outcome in patients with AKI, stratified according to severity of disease and randomized to different treatment options.

METHODS

This was a multicentre prospective randomized controlled trial with stratification according to severity of disease expressed by the SHARF score. ICU patients were eligible for inclusion when serum creatinine was >2 mg/dL, and RRT was initiated. The selected patients were randomized to intermittent (IRRT) or continuous renal replacement therapy (CRRT).

RESULTS

A total of 316 AKI patients were randomly assigned to IRRT (n = 144) or CRRT (n = 172). The mean age was 66 (range 18-96); 59% were male. Intention-to-treat analysis revealed a mortality of 62.5% in IRRT compared to 58.1% in CRRT (P = 0.430). No difference between IRRT and CRRT could be observed in the duration of ICU stay or hospital stay. In survivors, renal recovery at hospital discharge was comparable between both groups. Multivariate analysis, including the SHARF score, APACHE II and SOFA scores for correction of disease severity, showed no difference in mortality between both treatment modalities. This result was confirmed in pre-specified subgroup analysis (elderly, patients with sepsis, heart failure, ventilation) and after exclusion of possible confounders (early mortality, delayed ICU admission).

CONCLUSIONS

Modality of RRT, either CRRT or IRRT, had no impact on the outcome in ICU patients with AKI. Both modalities need to be considered as complementary in the treatment of AKI (Clinical Trial: SHARF 4, NCT00322933, http://ClinicalTrials.gov).

Renal replacement therapies: physiological review

INTRODUCTION

A physiological review on renal replacement therapies (RRT) is a challenging task: there is nothing "physiologic" about RRT, since the most accurate, safe and perfectly delivered extracorporeal therapy would still be far from "physiologically" replacing the function of the native kidney.

METHODS

This review will address the issues of physiology of fluid and solute removal, acid base control and impact on mortality during intermittent and continuous therapies: different RRT modalities and relative prescriptions will provide different "physiological clinical effects" to critically ill patients with acute kidney injury (AKI), with the aim of restoring lost "renal homeostasis". On the other side, however, the "pathophysiology" of RRT, consists with unwanted clinical effects caused by the same treatments, generally under-recognized by current literature but often encountered in clinical practice. Physiology and pathophysiology of different RRT modalities have been reviewed.

CONCLUSION

Physiology and pathophysiology of RRT often coexist during dialysis sessions. Improvement in renal recovery and survival from AKI will be achieved from optimization of therapy and increased awareness of potential benefits and dangers deriving from different RRT modalities.

Renal replacement therapy in acute kidney injury: intermittent versus continuous? How much is enough?

Approximately 4% of all critically ill patients will require renal replacement therapy (RRT). Despite its potential reversibility, acute kidney injury has a significant impact on morbidity and mortality. Numerous studies have addressed the questions of modality choice and dose of RRT in the intensive care unit setting. There is no clear evidence that one renal replacement modality is superior to another. Two multicenter trials focusing on dialysis dose will probably be published in the next year, either confirming or invalidating the benefit of higher effluent rates. Another key aspect in the treatment of acute kidney injury is the consequence of RRT on long-term renal function. Although cohort studies have shown that continuous RRT shortens dialysis-dependence compared with intermittent hemodialysis, randomized trials and meta-analyses do not support these findings. Several unanswered questions, such as the timing of initiation and cessation of RRT, the modification of dialysis parameters over the course of acute kidney injury and the influence of fluid status need to be addressed in future trials in order to improve outcomes related to this condition.

High volume peritoneal dialysis vs daily hemodialysis: a randomized, controlled trial in patients with acute kidney injury

There is no consensus in the literature on the best renal replacement therapy (RRT) in acute kidney injury (AKI), with both hemodialysis (HD) and peritoneal dialysis (PD) being used as AKI therapy. However, there are concerns about the inadequacy of PD as well as about the intermittency of HD complicated by hemodynamic instability. Recently, continuous replacement renal therapy (CRRT) have become the most commonly used dialysis method for AKI around the world. A prospective randomized controlled trial was performed to compare the effect of high volume peritoneal dialysis (HVPD) with daily hemodialysis (DHD) on AKI patient survival. A total of 120 patients with acute tubular necrosis (ATN) were assigned to HVPD or DHD in a tertiary-care university hospital. The primary end points were hospital survival rate and renal function recovery, with metabolic control as the secondary end point. Sixty patients were treated with HVPD and 60 with DHD. The HVPD and DHD groups were similar for age (64.2+/-19.8 and 62.5+/-21.2 years), gender (male: 72 and 66%), sepsis (42 and 47%), hemodynamic instability (61 and 63%), severity of AKI (Acute Tubular Necrosis-Index Specific Score (ATN-ISS): 0.68+/-0.2 and 0.66+/-0.2), Acute Physiology, Age, and Chronic Health Evaluation Score (APACHE II) (26.9+/-8.9 and 24.1+/-8.2), pre-dialysis BUN (116.4+/-33.6 and 112.6+/-36.8 mg per 100 ml), and creatinine (5.8+/-1.9 and 5.9+/-1.4 mg per 100 ml). Weekly delivered Kt/V was 3.6+/-0.6 in HVPD and 4.7+/-0.6 in DHD (P<0.01). Metabolic control, mortality rate (58 and 53%), and renal function recovery (28 and 26%) were similar in both groups, whereas HVPD was associated with a significantly shorter time to the recovery of renal function. In conclusion, HVPD and DHD can be considered as alternative forms of RRT in AKI.