Long-term outcome of COVID-19 patients with acute kidney injury requiring kidney replacement therapy

BACKGROUND

Limited data existed on the burden of coronavirus disease 2019 (COVID-19) renal complications and the outcomes of the most critical patients who required kidney replacement therapy (KRT) during intensive care unit (ICU) stay. We aimed to describe mortality and renal function at 90 days in patients admitted for COVID-19 and KRT.

METHODS

A retrospective cohort study of critically ill patients admitted for COVID-19 and requiring KRT from March 2020 to January 2022 was conducted in an Italian ICU from a tertiary care hospital. Primary outcome was mortality at 90 days and secondary outcome was kidney function at 90 days.

RESULTS

A cohort of 45 patients was analyzed. Mortality was 60% during ICU stay and increased from 64% at the time of hospital discharge to 71% at 90 days. Among 90-day survivors, 31% required dialysis, 38% recovered incompletely, and 31% completely recovered renal function. The probability of being alive and dialysis-free at 3 months was 22%.

CONCLUSIONS

Critically ill patients with COVID-19 disease requiring KRT during ICU stay had elevated mortality rate at 90 days, with low probability of being alive and dialysis-free at 3 months. However, a non-negligible number of patients completely recovered renal function.

The Spectrum of Biopsy-Proven Kidney Diseases, Causes, and Renal Outcomes in Acute Kidney Injury Patients

INTRODUCTION

Acute kidney injury (AKI) is a group of highly heterogeneous, complicated clinical syndromes. Although kidney biopsy plays an irreplaceable role in evaluating complex AKI, a few studies have focused on the clinicopathology of AKI biopsies. This study analyzed the pathological disease spectrum, causes, and renal outcomes of biopsied AKI patients.

METHODS

We retrospectively included 2,027 AKI patients who underwent kidney biopsies at a national clinical research center of kidney diseases from 2013 through 2018. To compare the biopsied AKI cases without and with coexisting glomerulopathy, patients were classified into acute tubular/tubulointerstitial nephropathy-associated AKI (ATIN-AKI) and glomerular disease-associated AKI (GD-AKI) groups.

RESULTS

Of 2,027 biopsied AKI patients, 65.1% were male, with a median age of 43 years. A total of 1,590 (78.4%) patients had coexisting GD, while only 437 (21.6%) patients had ATIN alone. The AKI patients with GD mainly (53.5%) manifested as stage 1 AKI, while most ATIN-AKI patients (74.8%) had stage 3 AKI. In the ATIN-AKI group, 256 (58.6%) patients had acute interstitial nephritis (AIN), and 77 (17.6%) had acute tubular injury (ATI). ATIN-AKI was mainly caused by drugs in 85.5% of AIN and 63.6% of ATI cases, respectively. In AKI patients with coexisting GD, the leading pathological diagnoses in over 80% of patients were IgA nephropathy (IgAN, 22.5%), minimal change disease (MCD, 17.5%), focal segmental glomerulosclerosis (FSGS, 15.3%), lupus nephritis (LN, 11.9%), membranous nephropathy (MN, 10.2%), and ANCA-associated vasculitis (AAV, 4.7%). A total of 775 patients were followed up within 3 months after renal biopsy; ATIN-AKI patients achieved statistically higher complete renal recovery than the GD-AKI patients (83.5% vs. 70.5%, p < 0.001).

CONCLUSIONS

Most biopsied AKI patients have coexisting GD, while ATIN alone is seen less frequently. ATIN-AKI is mainly caused by drugs. In GD-AKI patients, IgAN, MCD, FSGS, LN, MN, and AAV are the leading diagnoses. Compared to AKI patients without GD, patients with GD suffer from worse renal function recovery.

Acute Kidney Injury: Clinical Characteristics and Short-Term Outcomes in 1,519 Patients

Introduction

Complex integrated information on disease mechanisms and in-hospital outcomes in mild to moderate acute kidney injury (AKI) is scarce.

Methods

The Stockholm Prospective AKI Cohort Study (SAKIS) included all patients (≥18 years, n = 1,519) with community-acquired AKI (KDIGO criteria) admitted to the nephrology ward at Danderyd University Hospital, Stockholm, Sweden, between 2009 and 2018. Detailed laboratory measures were registered. Odds ratio for hypo- and hyperkalemia, recovery of kidney function by 30% and 50%, and in-hospital mortality were assessed by logistic regression analysis.

Results

Factors independently associated with the presence of hyperkalemia at admission were high age, high serum creatinine (sCr), and low C-reactive protein (CRP). Signs of malnutrition, inflammation, and acidosis were seen in 31% of patients. Kidney recovery, defined as a reduction of sCr by 30% in-hospital (63% of all patients), was associated with higher age, female sex, lower body mass index (BMI), higher hemoglobin, and higher CRP. Factors independently associated with mortality (4.4% of patients) were high age, high BMI, and low albumin.

Conclusion

This study provides a detailed description of community-acquired AKI and comprehensive analyses of integrated clinical and laboratory data associated with kidney recovery. Features related to anemia, albuminuria, malnutrition, inflammation, and acidosis associate with partial or moderate short-term recovery of kidney function, with disturbances in potassium homeostasis, and with in-hospital mortality. Future studies are warranted to analyze the long-term consequences of AKI in terms of risk of kidney failure, cardiovascular morbidity, and mortality.

Recovery From Acute Kidney Injury Requiring Dialysis in Patients With Cirrhosis: A Population-Based Study

RATIONALE & OBJECTIVE

The decision to initiate kidney replacement therapy (KRT) for acute kidney injury (AKI) in cirrhosis remains controversial as it is unclear which patients will benefit. We sought to characterize factors associated with recovery from AKI requiring KRT in patients with cirrhosis to inform shared clinical decision-making.

STUDY DESIGN

Population-based retrospective cohort study.

SETTING & PARTICIPANTS

Adult patients from Ontario, Canada identified, using administrative data, to have cirrhosis at the time of admission to hospital with AKI (based on serum creatinine) requiring KRT (01/01/2009-12/31/2016) and followed until 12/31/2017.

EXPOSURES

Demographics and comorbidities prior to admission.

OUTCOMES

Kidney recovery defined as the absence of KRT for at least 30 days.

ANALYTICAL APPROACH

The cumulative incidences of kidney recovery, death, and liver transplantation were calculated at 1, 3, 6, and 12 months and independent predictors of kidney recovery were evaluated using Fine and Gray competing risk regression models that generated subdistribution hazards ratios (sHR).

RESULTS

Overall, 722 patients were included (median age 61 years [IQR 54-68]; MELD-Na 26 [IQR 22-34]; 66% male; 52% had viral hepatitis, 25% non-alcoholic fatty liver disease, 18% alcohol-associated liver disease). The cumulative incidences of kidney recovery at 1, 3, 6, and 12 months were 3%, 22%, 25%, and 26%, respectively. Higher MELD-Na score (sHR 0.72 per 5 units, 95%CI 0.65-0.80), acute-on-chronic liver failure (sHR 0.61, 95%CI 0.43-0.86), and sepsis (sHR 0.57, 95%CI 0.41-0.81) were associated with a lower hazard of kidney recovery while those on a liver transplant waitlist (sHR 3.10, 95% CI 1.96-4.88) and who were admitted to a teaching hospital (sHR 1.48, 95%CI 1.05-2.08) were more likely to experience kidney recovery.

LIMITATIONS

Observational design, AKI etiology not identified.

CONCLUSIONS

Kidney recovery from KRT occurred in only one-quarter of patients and was very unlikely after 3-months. These findings provide information regarding prognosis that may guide decisions regarding KRT initiation and continuation.

Recovery after acute kidney injury requiring kidney replacement therapy in patients with left ventricular assist device: A meta-analysis

BACKGROUND

Acute kidney injury (AKI) is a common and severe complication after left ventricular assist device (LVAD) implantation with an incidence of 37%; 13% of which require kidney replacement therapy (KRT). Severe AKI requiring KRT (AKI-KRT) in LVAD patients is associated with high short and long-term mortality compared with AKI without KRT. While kidney function recovery is associated with better outcomes, its incidence is unclear among LVAD patients with severe AKI requiring KRT.

AIM

To identify studies evaluating the recovery rates from severe AKI-KRT after LVAD placement, which is defined by regained kidney function resulting in the discontinuation of KRT. Random-effects and generic inverse variance method of DerSimonian-Laird were used to combine the effect estimates obtained from individual studies.

METHODS

A total of 268 patients from 14 cohort studies that reported severe AKI-KRT after LVAD were included. Follow-up time ranged anywhere from two weeks of LVAD implantation to 12 mo. Kidney recovery occurred in 78% of enrollees at the time of hospital discharge or within 30 d. Overall, the pooled estimated AKI recovery rate among patients with severe AKI-KRT was 50.5% (95%CI: 34.0%-67.0%) at 12 mo follow up. Majority (85%) of patients used continuous-flow LVAD. While the data on pulsatile-flow LVAD was limited, subgroup analysis of continuous-flow LVAD demonstrated that pooled estimated AKI recovery rate among patients with severe AKI-KRT was 52.1% (95%CI: 36.8%-67.0%). Meta-regression analysis did not show a significant association between study year and AKI recovery rate (P = 0.08). There was no publication bias as assessed by the funnel plot and Egger's regression asymmetry test in all analyses.

RESULTS

A total of 268 patients from 14 cohort studies that reported severe AKI-KRT after LVAD were included. Follow-up time ranged anywhere from two weeks of LVAD implantation to 12 mo. Kidney recovery occurred in 78% of enrollees at the time of hospital discharge or within 30 d. Overall, the pooled estimated AKI recovery rate among patients with severe AKI-KRT was 50.5% (95%CI: 34.0%-67.0%) at 12 mo follow up. Majority (85%) of patients used continuous-flow LVAD. While the data on pulsatile-flow LVAD was limited, subgroup analysis of continuous-flow LVAD demonstrated that pooled estimated AKI recovery rate among patients with severe AKI-KRT was 52.1% (95%CI: 36.8%-67.0%). Meta-regression analysis did not show a significant association between study year and AKI recovery rate (P = 0.08). There was no publication bias as assessed by the funnel plot and Egger's regression asymmetry test in all analyses.

CONCLUSION

Recovery from severe AKI-KRT after LVAD occurs approximately 50.5%, and it has not significantly changed over the years despite advances in medicine.

Predictors of kidney function recovery among incident ESRD patients

Background

ESRD is considered an irreversible loss of renal function, yet some patients will recover kidney function sufficiently to come off dialysis. Potentially modifiable predictors of kidney recovery, such as dialysis prescription, have not been fully examined.

Methods

Retrospective cohort study using United States Renal Data System (USRDS) data to identify incident hemodialysis (HD) patients between 2012 and 2016, the first 4 years for which dialysis treatment data is available. The primary outcome was kidney recovery within 1 year of ESRD and HD initiation, defined by a specific recovery code and survival off dialysis for at least 30 days. Patient and treatment characteristics were compared between those that recovered versus those that remained dialysis-dependent. A time-dependent survival model was used to identify independent predictors of kidney recovery.

Results

During the study period, there were 372,387 incident HD patients with available data, among whom 16,930 (4.5%) recovered to dialysis-independence. Compared to non-recovery, a higher proportion of patients with kidney recovery were of white race, and non-Hispanic ethnicity. Both groups had a similar age distribution. Patients with an acute kidney injury diagnosis as primary cause of ESRD were most likely to recover, but the most common ESRD diagnosis among recovering patients was type 2 diabetes (29.8% of recovery cases). Higher eGFR and lower albumin at ESRD initiation were associated with increased likelihood of recovery. When examining HD ultrafiltration rate (UFR), each quintile above the first quintile was associated with a progressively lower likelihood of recovery (HR 0.45, 95% CI 0.43–0.48 for highest versus lowest quintile, p < 0.001).

Conclusions

We identified non-modifiable and potentially modifiable factors associated with kidney recovery which may assist clinicians in counseling and monitoring incident ESRD patients with a greater chance to gain dialysis-independence. Clinical trials are warranted to examine the impact of dialysis prescription on subsequent kidney function recovery.

Renal Functional Recovery Confounding the Assessment of Contrast Nephropathy: Propensity Score Analysis

BACKGROUND

Large data analyses confirm the relative safety of contrast-enhanced computed tomography (CT), except for those with advanced renal failure. However, the prevalence of post-contrast acute kidney injury may be masked by acute kidney functional recovery (AKR) in unstable inpatients, irrespective of contrast-enhanced imaging.

METHODS

In this work we aimed to assess AKI and AKR along with need for dialysis and mortality, among inpatients undergoing contrast-enhanced or non-enhanced CT. We performed a large-scale retrospective data analysis using propensity score matching (PSM) that compared patients undergoing contrast-enhanced and non-enhanced imaging. We also performed a subgroup analysis of subjects stratified by baseline renal function.

RESULTS

A total of 41,456 patients were analyzed. PSM resulted in well-balanced groups. AKR occurred substantially more often than AKI among hospitalized patients following CT imaging, especially among those with low baseline renal function. Yet, in this population, whereas the rate of AKI significantly increased, the rate of AKR significantly decreased following contrast-enhanced studies as compared to patients that underwent non-enhanced CT. A significantly higher proportion of patients with baseline advanced renal failure that underwent contrast-enhanced imaging required dialysis.

CONCLUSIONS

The increased incidence of AKI and AKR as seen in patients with lower pre-imaging kidney function possibly suggests that both entities reflect impaired renal functional reserve. Unstable kidney function in inpatients, as demonstrated by rates of AKR and AKI, is an important confounder which requires attention in similar observational studies on the renal effects of contrast media and of various other renal injurious events.

Acute Kidney Disease to Chronic Kidney Disease

Acute kidney injury (AKI) and chronic kidney disease are common interconnected syndromes that represent a public health problem. Acute kidney disease (AKD) is defined as the post-AKI status of acute or subacute kidney damage/dysfunction manifested by persistence of AKI beyond 7 to 90 days after the initial AKI diagnosis. Limited clinical data exist regarding AKD epidemiology but its incidence is observed in ∼25% of AKI survivors. Useful risk-stratification tools to predict risk of AKD and its prognosis are needed. Interventions on fluid management, nephrotoxic exposure, and follow-up care hold promise to ameliorate the burden of AKD and its complications.

Outpatient kidney recovery after acute kidney injury requiring dialysis: a systematic review protocol

BACKGROUND

Acute kidney injury requiring dialysis (AKI-D) during hospitalization is associated with both in-hospital and post-discharge mortality. Its incidence has risen over time in Canada and the USA. While the majority of AKI-D will recover to dialysis independence at the time of hospital discharge, 10-30% will transition to outpatient dialysis. The risk factors that determine dialysis independence after AKI-D and its optimal outpatient management remain unclear. Eliciting prognostic predictors of kidney recovery in patients who remain on dialysis after hospital discharge will guide subsequent clinical decision making. The objective of this study is to assess the association between patient- and treatment-related factors with short- and long-term outcomes in patients who remained dialysis-dependent after hospitalization with AKI-D.

METHODS

A literature search in EMBASE, MEDLINE, and PubMed will be performed based on pre-specified criteria. There are no restrictions on language and publication dates. The supplemental search will include manual scan of bibliographies of eligible studies and grey literature assessment. Pre-specified criteria will be used to select eligible studies. Relevant data will be extracted and quality assessments performed per validated tools. Qualitative data synthesis will be performed to reflect directions of associations. Meta-analysis will be formed if two or more studies with similar prognostic factors, outcomes, and adequate quality are identified. Strength of association will be quantified as odds ratios. Reporting of this review will be guided by recommendations of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement.

DISCUSSION

This systematic review aims to synthesize association between modifiable and non-modifiable prognostic factors with renal outcomes in AKI-D patients who remain dialysis-dependent after hospital discharge. Our findings will help inform the development of evidence-based management and guide long-term treatment planning for AKI-D patients.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration number CRD42019127394 .

Effect of decompressive laparotomy on organ function in patients with abdominal compartment syndrome: a systematic review and meta-analysis

BACKGROUND

Decompressive laparotomy has been advised as potential treatment for abdominal compartment syndrome (ACS) when medical management fails; yet, the effect on parameters of organ function differs markedly in the published literature. In this study, we sought to investigate the effect of decompressive laparotomy on intra-abdominal pressure and organ function in critically ill adult and pediatric patients with ACS, specifically focusing on hemodynamic, respiratory, and kidney function and outcome.

METHODS

A systematic review and meta-analysis of the literature was performed. Articles reporting data on intra-abdominal pressure (IAP), hemodynamic (mean arterial pressures [MAP], central venous pressure [CVP], cardiac index [CI], heart rate [HR], systemic vascular resistance index [SVRI] and/or pulmonary capillary wedge pressure [PCWP]), respiratory (positive end-expiratory pressure [PEEP], peak inspiratory pressure [PIP] and/or ratio of partial pressure arterial oxygen and fraction of inspired oxygen [P/F ratio]), and/or urinary output (UO) following decompressive laparotomy were analyzed.

RESULTS

A total of 15 articles were included; 3 included children only (aged 18 years or younger). Of the 286 patients who were included, 49.7% had primary ACS. The baseline mean IAP in adults decreased with an average of 18.2 ± 6.5 mmHg following decompression, from 31.7 ± 6.4 mmHg to 13.5 ± 3.0 mmHg. There was a decrease in HR (12.2 ± 9.5 beats/min; p = 0.04), CVP (4.6 ± 2.3 mmHg; p = 0.022), PCWP (5.8 ± 2.3 mmHg; p = 0.029), and PIP (10.1 ± 3.9 cmH2O; p < 0.001) and a mean increase in P/F ratio (70.4 ± 49.4; p < 0.001) and UO (95.3 ± 105.3 ml/h; p < 0.001). In children, there was a significant increase in MAP (20.0 ± 2.3 mmHg; p = 0.006), P/F ratio (238.2; p < 0.001), and UO (2.88 ± 0.64 ml/kg/h; p < 0.001) and a decrease in CVP (7 mmHg; p = 0.016) and PIP (9.9 cmH2O; p = 0.002). The overall mortality rate was 49.7% in adults and 60.8% in children following decompressive laparotomy.

CONCLUSIONS

Decompressive laparotomy resulted in a significantly lower IAP and had beneficial effects on hemodynamic, respiratory, and renal parameters. Mortality after decompressive laparotomy remains high in both adults and children.

Associations of fluid overload with mortality and kidney recovery in patients with acute kidney injury: A systematic review and meta-analysis

PURPOSE

Fluid resuscitation is commonly administered to maintain adequate renal perfusion in critically ill patients to prevent or even treat acute kidney injury (AKI). However, recent studies show that fluid overload is common and might be associated with poor outcomes in patients with AKI. Hence, the objective of this study was to assess the associations of fluid overload with mortality and kidney recovery in patients with AKI.

MATERIALS AND METHODS

We electronically searched original articles published in peer-reviewed journals from their inception to January 2015 in PubMed, EMBASE, the Cochrane Library databases, Google Scholar, and Chinese database (SinoMed). We additionally searched the reference lists of all retrieved articles. We performed a systematic review and meta-analysis of all eligible cohort or case-control studies of fluid overload in patients with AKI. The primary outcomes were mortality and kidney recovery. We pooled adjusted odds ratios (ORs) with 95% confidence intervals (95% CIs) by using Review Manager 5.2 (The Cochrane Collaboration, Oxford, UK).

RESULTS

A total of 5095 patients from 12 cohort studies published from 2008 to 2014 were included. A significant positive association was found between fluid overload and mortality in patients with AKI (OR, 2.23; 95% CI, 1.66-3.01), with similar findings in sepsis (OR, 2.27; 95% CI, 1.69-to 3.03) and nonsepsis subgroups (OR, 3.40; 95% CI, 2.50-4.63). There was also a significant association between mean fluid balance (continuous variables) and mortality (OR, 1.16; 95% CI, 1.07-1.27). Although there was a trend of lower rate of kidney recovery in the fluid overload group, there was no significant association between fluid overload and kidney recovery (OR, 0.66; 95% CI, 0.37-1.15), or dialysis dependence (OR, 0.72; 95% CI, 0.38-1.35).

CONCLUSIONS

Fluid overload is associated with an increased risk of mortality in patients with AKI. The evidence of the relationship between fluid overload and kidney recovery is insufficient.