Comparison of outcomes by modality for critically ill patients requiring renal replacement therapy: a single-centre cohort study adjusting for time-varying illness severity and modality exposure

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

BACKGROUND

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

AIM

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Nonrandomized studies using causal-modeling may give different answers than RCTs: a meta-epidemiological study

OBJECTIVES

To evaluate how estimated treatment effects agree between nonrandomized studies using causal modeling with marginal structural models (MSM-studies) and randomized trials (RCTs).

STUDY DESIGN

Meta-epidemiological study.

SETTING

MSM-studies providing effect estimates on any healthcare outcome of any treatment were eligible. We systematically sought RCTs on the same clinical question and compared the direction of treatment effects, effect sizes, and confidence intervals.

RESULTS

The main analysis included 19 MSM-studies (1,039,570 patients) and 141 RCTs (120,669 patients). MSM-studies indicated effect estimates in the opposite direction from RCTs for eight clinical questions (42%), and their 95% CI (confidence interval) did not include the RCT estimate in nine clinical questions (47%). The effect estimates deviated 1.58-fold between the study designs (median absolute deviation OR [odds ratio] 1.58; IQR [interquartile range] 1.37 to 2.16). Overall, we found no systematic disagreement regarding benefit or harm but confidence intervals were wide (summary ratio of odds ratios [sROR] 1.04; 95% CI 0.88 to 1.23). The subset of MSM-studies focusing on healthcare decision-making tended to overestimate experimental treatment benefits (sROR 1.44; 95% CI 0.99 to 2.09).

CONCLUSION

Nonrandomized studies using causal modeling with MSM may give different answers than RCTs. Caution is still required when nonrandomized "real world" evidence is used for healthcare decisions.

Effect of sustained low efficient dialysis versus continuous renal replacement therapy on renal recovery after acute kidney injury in the intensive care unit: A systematic review and meta-analysis

Critically ill adults with acute kidney injury (AKI) experience considerable morbidity and mortality. Controversy remains regarding the optimal renal replacement intervention for these patients. Our systematic review aimed to determine the effect(s) of sustained low-efficiency dialysis (SLED) compared with continuous renal replacement (CRRT) therapy on relevant patient outcomes. A systematic search of Medline, Embase, CINAHL and the Cochrane Library was conducted. Identified citations were screened independently in duplicate for relevance, and the methodological quality of included studies was evaluated. Data were extracted on study, patient and intervention characteristics and relevant clinical outcomes. Results were pooled using inverse variance fixed and random effects meta-analysis. A total of 1564 patients from 18 studies were included. Meta-analysis results indicated no statistically significant difference in our primary outcome, overall proportion of renal recovery (risk ratio (RR) 0.87, 95% confidence interval (CI) 0.63-1.20, I2 = 66%). No significant difference was observed for the secondary outcome of time to renal recovery (mean difference 1.33, 95% CI 0.23-2.88, I2 = 0%). Statistically, SLED was marginally favoured over CRRT for the secondary outcome of mortality (RR 1.21, 95% CI 1.02-1.43, I2 = 47%); however, this diminished when sensitivity analysis of only randomized controlled trials was conducted (RR 1.25, 95% CI 1.00-1.57, I2 = 0%). There appears to be no clear for advantage continuous renal replacement in the hemodynamically unstable patient. Currently, both modalities are safe and effective means of treating AKI in the critically ill adult.

Modality of RRT and Recovery of Kidney Function after AKI in Patients Surviving to Hospital Discharge

BACKGROUND AND OBJECTIVES

Observational evidence has suggested that RRT modality may affect recovery after AKI. It is unclear whether initial choice of intermittent hemodialysis or continuous RRT affects renal recovery, survival, or development of ESRD in critically ill patients when modality choice is made primarily on hemodynamics.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We performed a retrospective cohort study examining adults (≥18 years old) admitted to intensive care units from 2000 to 2008 who received RRT for AKI and survived to hospital discharge or 90 days. We analyzed renal recovery (alive and not requiring RRT) and reasons for nonrecovery (death or ESRD) at 90 and 365 days. Conditional multivariable logistic regression was used to assess differences in renal recovery at 90 and 365 days between continuous RRT and intermittent hemodialysis. Models were stratified by propensity for continuous RRT and adjusted for age and reference creatinine.

RESULTS

Of 4738 patients with Kidney Disease Improving Global Outcomes stage 3 AKI, 1338 (28.2%) received RRT, and 638 (47.7%) survived to hospital discharge (353 intermittent hemodialysis and 285 continuous RRT). Recovery from AKI was lower for intermittent hemodialysis versus continuous RRT at 90 days (66.6% intermittent hemodialysis versus 75.4% continuous RRT; P=0.02) but similar at 365 days (54.1% intermittent hemodialysis versus 59.6% continuous RRT; P=0.17). In multivariable analysis, there was no difference in odds of recovery at 90 or 365 days for patients initially treated with continuous RRT versus intermittent hemodialysis (90 days: odds ratio, 1.19; 95% confidence interval, 0.91 to 1.55; P=0.20; 365 days: odds ratio, 0.93; 95% confidence interval, 0.72 to 1.2; P=0.55).

CONCLUSIONS

We found no significant difference in hazards for nonrecovery or reasons for nonrecovery (mortality or ESRD) with intermittent hemodialysis versus continuous RRT. These results suggest that, when initial RRT modality is chosen primarily on hemodynamics, renal recovery and clinical outcomes in survivors are similar between intermittent hemodialysis and continuous RRT.

Application of continuous renal replacement therapy for acute kidney injury in elderly patients

This study aims to analyze the factors that affect the prognosis of continuous renal replacement therapy (CRRT) in elderly patients with acute kidney injury (AKI). Data obtained from 41 elderly patients with AKI who underwent CRRT in our department between January 2001 and December 2010 was retrospectively evaluated in this study. The enrolled patients were 80 to 100 years old, with a mortality of 60.98%. The mean Acute Physiology and Chronic Health Evaluation II (APACHE II) score was 27.8±5.6 points, and the mean risk coefficient was 0.80±0.10. The APACHE II score of the survival group was significantly higher than that of the death group. The comparisons of therapeutic dosages between <25 mL/(kg⋅h) and 25-50 mL/(kg⋅h), and between 25-50 mL/(kg⋅h) and >50 mL/(kg⋅h) all had no statistical significance. The prognosis of CRRT and the number of involved organs were related to the APACHE II score. Logistic regression analysis revealed that the number of involved organ, APACHE II score, mechanical ventilation, and hypoalbuminemia were the major risk coefficients that affected the prognosis of patients with bedside hemofiltration. The turnover of elderly CRRT patients was related to the number of involved organs, APACHE II score, mechanical ventilation, hypoalbuminemia, and other factors. The APACHE II score was the important reference index of CRRT starting time and could predict mortality risk.

Extended Daily Dialysis Versus Continuous Renal Replacement Therapy for Acute Kidney Injury: A Meta-analysis

BACKGROUND

Extended daily dialysis (EDD) has been suggested as an effective renal replacement therapy for acute kidney injury. However, results from studies comparing EDD to continuous renal replacement therapy (CRRT) are inconclusive.

STUDY DESIGN

A systematic review and meta-analysis was performed by searching in MEDLINE, EMBASE, the Cochrane Library, Google Scholar, and a Chinese database (SinsoMed).

SETTING & POPULATION

Patients with acute kidney injury.

SELECTION CRITERIA FOR STUDIES

Randomized controlled trials (RCTs) and observational studies were included. EDD was defined as extended hemodialysis or hemodiafiltration for more than 6 but less than 24 hours per session using a conventional hemodialysis machine.

INTERVENTION

Renal replacement therapy comparing EDD with CRRT.

OUTCOMES

Mortality, kidney recovery, and fluid removal.

RESULTS

We included 17 studies from 2000 to 2014: 7 RCTs and 10 observational studies involving 533 and 675 patients, respectively. Meta-analysis of RCTs showed no difference in mortality rates between EDD and CRRT (relative risk, 0.90; 95% CI, 0.74-1.11; P=0.3). However, EDD was associated with lower mortality risk compared with CRRT in observational studies (relative risk, 0.86; 95% CI, 0.74-1.00; P=0.05). There was no evidence of heterogeneity in RCTs (I(2)=0%) or observational studies (I(2)=15%). In both RCTs and observational studies, there were no significant differences in recovery of kidney function, fluid removal, or days in the intensive care unit, and EDD showed similar biochemical efficacy to CRRT during treatment (serum urea, serum creatinine, and serum phosphate).

LIMITATIONS

The survival benefit of EDD is dependent on only observational studies and might have been affected by allocation or selection bias.

CONCLUSIONS

EDD is associated with similar outcomes to CRRT in RCTs. The finding that EDD is associated with a lower mortality rate relies on data from observational studies, which are potentially subject to allocation or selection bias, making further high-quality RCTs desirable.

Choice of renal replacement therapy modality and dialysis dependence after acute kidney injury: a systematic review and meta-analysis

PURPOSE

Choice of renal replacement therapy (RRT) modality may affect renal recovery after acute kidney injury (AKI). We sought to compare the rate of dialysis dependence among severe AKI survivors according to the choice of initial renal replacement therapy (RRT) modality applied [continuous (CRRT) or intermittent (IRRT)].

METHODS

Systematic searches of peer-reviewed publications in MEDLINE and EMBASE were performed (last update July 2012). All studies published after 2000 reporting dialysis dependence among survivors from severe AKI requiring RRT were included. Data on follow-up duration, sex, age, chronic kidney disease, illness severity score, vasopressors, and mechanical ventilation were extracted when available. Results were pooled using a random-effects model.

RESULTS

We identified 23 studies: seven randomized controlled trials (RCTs) and 16 observational studies involving 472 and 3,499 survivors, respectively. Pooled analyses of RCTs showed no difference in the rate of dialysis dependence among survivors (relative risk, RR 1.15 [95 % confidence interval (CI) 0.78-1.68], I(2) = 0 %). However, pooled analyses of observational studies suggested a higher rate of dialysis dependence among survivors who initially received IRRT as compared with CRRT (RR 1.99 [95 % CI 1.53-2.59], I (2) = 42 %). These findings were consistent with adjusted analyses (performed in 7/16 studies), which found a higher rate of dialysis dependence in IRRT-treated patients [odds ratio (OR) 2.2-25 (5 studies)] or no difference (2 studies).

CONCLUSIONS

Among AKI survivors, initial treatment with IRRT might be associated with higher rates of dialysis dependence than CRRT. However, this finding largely relies on data from observational trials, potentially subject to allocation bias, hence further high-quality studies are necessary.