Cost-effectiveness and value of information analysis of NephroCheck and NGAL tests compared to standard care for the diagnosis of acute kidney injury

BACKGROUND

Early and accurate acute kidney injury (AKI) detection may improve patient outcomes and reduce health service costs. This study evaluates the diagnostic accuracy and cost-effectiveness of NephroCheck and NGAL (urine and plasma) biomarker tests used alongside standard care, compared with standard care to detect AKI in hospitalised UK adults.

METHODS

A 90-day decision tree and lifetime Markov cohort model predicted costs, quality adjusted life years (QALYs) and incremental cost-effectiveness ratios (ICERs) from a UK NHS perspective. Test accuracy was informed by a meta-analysis of diagnostic accuracy studies. Clinical trial and observational data informed the link between AKI and health outcomes, health state probabilities, costs and utilities. Value of information (VOI) analysis informed future research priorities.

RESULTS

Under base case assumptions, the biomarker tests were not cost-effective with ICERs of £105,965 (NephroCheck), £539,041 (NGAL urine BioPorto), £633,846 (NGAL plasma BioPorto) and £725,061 (NGAL urine ARCHITECT) per QALY gained compared to standard care. Results were uncertain, due to limited trial data, with probabilities of cost-effectiveness at £20,000 per QALY ranging from 0 to 99% and 0 to 56% for NephroCheck and NGAL tests respectively. The expected value of perfect information (EVPI) was £66 M, which demonstrated that additional research to resolve decision uncertainty is worthwhile.

CONCLUSIONS

Current evidence is inadequate to support the cost-effectiveness of general use of biomarker tests. Future research evaluating the clinical and cost-effectiveness of test guided implementation of protective care bundles is necessary. Improving the evidence base around the impact of tests on AKI staging, and of AKI staging on clinical outcomes would have the greatest impact on reducing decision uncertainty.

Incremental Cost of Acute Kidney Injury after Percutaneous Coronary Intervention in the United States

Contrast-induced acute kidney injury (AKI) is a common and severe complication of percutaneous coronary intervention (PCI). Despite its substantial burden, contemporary data on the incremental costs of AKI are lacking. We designed this large, nationally representative study to examine: (1) the independent, incremental costs associated with AKI after PCI and (2) to identify the departmental components of cost contributing to the incremental costs associated with AKI. In this observational cross-sectional study from the Premier database, we analyzed 1,443,297 PCI patients at 518 US hospitals from 1/2006 to 12/2015. Incremental cost of AKI from a hospital perspective obtained by a microcosting approach, was estimated using mixed-effects, multivariable linear regression with hospitals as random effects. Costs were inflation-corrected to 2016 US$. AKI occurred in 82,683 (5.73%) of the PCI patients. Those with AKI had higher hospitalization cost than those without ($38,869, SD 42,583 vs $17,167 SD 13,994, p <0.001). After adjustment, the incremental cost associated with an AKI was $9,448 (95% confidence interval $9,338 to $9,558, p <0.001). AKI was also independently associated with an incremental length of stay of 3.6 days (p <0.001). Room and board costs were the largest driver of AKI costs ($4,841). Extrapolated to the United States, our findings imply an annual AKI cost burden of 411.3 million US$. In conclusion, in this national study of PCI patients, AKI was common and independently associated with ∼$10,000 incremental costs, implying a substantial burden of AKI costs in US hospitals. Successful efforts to prevent AKI in patients who underwent PCI could result in meaningful cost savings.

Hospital costs associated with intraoperative hypotension among non-cardiac surgical patients in the US: a simulation model

Objective: Recent studies indicate intraoperative hypotension, common in non-cardiac surgical patients, is associated with myocardial injury, acute kidney injury, and mortality. This study extends on these findings by quantifying the association between intraoperative hypotension and hospital expenditures in the US. Methods: Monte Carlo simulations (10,000 trial per simulation) based on current epidemiological and cost outcomes literature were developed for both acute kidney injury (AKI) and myocardial injury in non-cardiac surgery (MINS). For AKI, three models with different epidemiological assumptions (two models based on observational studies and one model based on a randomized control trial [RCT]) estimate the marginal probability of AKI conditional on intraoperative hypotension status. Similar models are also developed for MINS (except for the RCT case). Marginal probabilities of AKI and MINS sequelae (myocardial infarction, congestive heart failure, stroke, cardiac catheterization, and percutaneous coronary intervention) are multiplied by marginal cost estimates for each outcome to evaluate costs associated with intraoperative hypotension. Results: The unadjusted (adjusted) model found hypotension control lowers the absolute probability of AKI by 2.2% (0.7%). Multiplying these probabilities by the marginal cost of AKI, the unadjusted (adjusted) AKI model estimated a cost reduction of $272 [95% CI = $223-$321] ($86 [95% CI = $47-$127]) per patient. The AKI model based on relative risks from the RCT had a mean cost reduction estimate of $281 (95% CI = -$346-$750). The unadjusted (adjusted) MINS model yielded a cost reduction of $186 [95% CI = $73-$393] ($33 [95% CI = $10-$77]) per patient. Conclusions: The model results suggest improved intraoperative hypotension control in a hospital with an annual volume of 10,000 non-cardiac surgical patients is associated with mean cost reductions ranging from $1.2-$4.6 million per year. Since the magnitude of the RCT mean estimate is similar to the unadjusted observational model, the institutional costs are likely at the upper end of this range.

A Monte Carlo simulation estimating US hospital cost reductions associated with hypotension control in septic ICU patients

OBJECTIVE

This economic analysis extends upon a recent epidemiological study to estimate the association between hypotension control and hospital costs for septic patients in US intensive care units (ICUs).

METHODS

A Monte Carlo simulation decision analytic model was developed that accounted for the probability of complications-acute kidney injury and mortality-in septic ICU patients and the cost of each health outcome from the hospital perspective. Probabilities of complications were calculated based on observational data from 110 US hospitals for septic ICU patients (n = 8,782) with various levels of hypotension exposure as measured by mean arterial pressure (MAP, units: mmHg). Costs for acute kidney injury (AKI) and mortality were derived from published literature. Each simulation calculated mean hospital cost reduction and 95% confidence intervals based on 10,000 trials.

RESULTS

In the base-case analysis hospital costs for a hypothetical "control" cohort (MAP of 65 mmHg) were $699 less per hospitalization (95% CI: $342-$1,116) relative to a "case" cohort (MAP of 60 mmHg). In the most extreme case considered (45 mmHg vs 65 mmHg), the associated cost reduction was $4,450 (95% CI: $2,020-$7,581). More than 99% of the simulated trials resulted in cost reductions. A conservative institution-level analysis for a hypothetical hospital (which assumes no benefit for increasing MAP above 65 mmHg) estimated a cost decline of $417 for a 5 mmHg increase in MAP per ICU septic patient. These results are applicable to the US only.

CONCLUSIONS

Hypotension control (via MAP increases) for patients with sepsis in the ICU is associated with lower hospitalization cost.

Burden, Access, and Disparities in Kidney Disease

Kidney disease is a global public health problem, affecting over 750 million persons worldwide. The burden of kidney disease varies substantially across the world. In many settings, rates of kidney disease and the provision of its care are defined by socioeconomic, cultural, and political factors leading to significant disparities. World Kidney Day 2019 offers an opportunity to raise awareness of kidney disease and highlight disparities in its burden and current state of global capacity for prevention and management. Here, we highlight the need for strengthening basic infrastructure for kidney care services for early detection and management of acute kidney injury and chronic kidney disease across all countries and advocate for more pragmatic approaches to providing renal replacement therapies. Achieving universal health coverage worldwide by 2030 is a World Health Organization Sustainable Development Goal. While universal health coverage may not include all elements of kidney care in all countries, understanding what is locally feasible and important with a focus on reducing the burden and consequences of kidney disease would be an important step towards achieving kidney health equity.

Polymyxin B and colistin-the economic burden of nephrotoxicity against multidrug resistant bacteria

BACKGROUND

Polymyxin B and colistin are nephrotoxic drugs used in the treatment of carbapenem-resistant Enterobacteriaceae. The aim of this study is to evaluate the burden of costs due to polymyxin associated AKI and propose a simulated break-even price for new therapies.

METHODS

The pharmacoeconomic model is based on two large cross-sectional studies of polymyxin nephrotoxicity. Total direct costs in patients with and without renal failure were compared. The direct cost of each hemodialysis section (USD82.94) and daily hospital charges (USD934.85) were based on the values used in a major public hospital in the city where the clinical study was performed. The break-even price of new drugs was simulated considering eventual new drugs as effective as polymyxins, but less nephrotoxic in different percentages. Outcomes of patients after hospital discharge were not evaluated.

RESULTS

Total direct cost of the group of patients who survived without AKI was significantly lower than total direct cost of the groups either with AKI or the group who died without AKI. There was a tendency of even higher costs in those who died with AKI and dialysis. Direct cost of hemodialysis was not as important as the longer hospitalization after sepsis. Considering daily cost of polymyxin is USD60, drugs with 50% less AKI could be considered cost-beneficial if the daily cost is lower than USD160.

CONCLUSIONS

AKI in patients with carbapenem-resistant Enterobacteriaceae treated with polymyxin increases both length of stay in hospital and total costs.

Potential for Cost Saving with Iclaprim Owing to Avoidance of Vancomycin-Associated Acute Kidney Injury in Hospitalized Patients with Acute Bacterial Skin and Skin Structure Infections

BACKGROUND AND OBJECTIVE

Vancomycin is the most prescribed antibiotic for hospitalized adults with skin and skin structure infections. Vancomycin is associated with acute kidney injury. Iclaprim is an antibiotic under development for the treatment of patients with acute bacterial skin and skin structure infections and is not associated with acute kidney injury. This economic model sought to determine the potential cost saving with iclaprim owing to avoidance of vancomycin-associated acute kidney injury among hospitalized patients with acute bacterial skin and skin structure infections.

MATERIALS AND METHODS

A hospital cost-minimization model was developed to estimate the overall cost impact of replacing empiric vancomycin with iclaprim among hospitalized adult patients with skin and skin structure infections. The structural model included: vancomycin acquisition; vancomycin assay; incidence of vancomycin-associated acute kidney injury; excess hospital length of stay if acute kidney injury occurred; frequency/cost of specialty physician consults after occurrence of acute kidney injury; and probability/cost of acute dialysis as a result of acute kidney injury. Iclaprim treatment duration was 7 days and iclaprim acquisition cost was varied to determine the upper end of the daily iclaprim price that still conferred cost savings relative to vancomycin. Duration of hospitalization for iclaprim was assumed to be the same as patients with no acute kidney injury.

RESULTS

Based on the overall acute kidney injury rate (9.2%), the neutral acquisition price threshold for iclaprim vs. vancomycin was US$1373.47/regimen. Across various subpopulations where acute kidney injury risk ranged between 9.2 and 16.7%, the daily iclaprim acquisition cost that still conferred cost savings was up to US$300/day.

CONCLUSIONS

Iclaprim has the potential to reduce the economic burden of acute bacterial skin and skin structure infections in hospitalized patients at risk for vancomycin-associated acute kidney injury when iclaprim acquisition is US$300/day or less.

The effect of major adverse renal cardiovascular event (MARCE) incidence, procedure volume, and unit cost on the hospital savings resulting from contrast media use in inpatient angioplasty

OBJECTIVE

To determine the net economic impact of switching from low-osmolar contrast media (LOCM) to iso-osmolar contrast media (IOCM; iodixanol) in patients undergoing inpatient coronary or peripheral angioplasty in the United States (US).

METHODS

A budget impact model (BIM) was developed from a hospital perspective. Nationally representative procedural and contrast media prevalence rates, along with MARCE (major adverse renal cardiovascular event) incidence and episode-related cost data were derived from Premier Hospital Data (October 2014 to September 2015). A previously estimated relative risk reduction in MARCE associated with IOCM usage (9.3%) was applied. The higher cost of IOCM was included when calculating the net impact estimates at the aggregate, hospital type, and per hospital levels. One-way (±25%) and probabilistic sensitivity analyses identified the model's most important inputs.

RESULTS

Based on weighted analysis, 513,882 US inpatient angioplasties and 35,610 MARCE cases were estimated annually. Switching to an "IOCM only" strategy from a "LOCM only" strategy increases contrast media cost, but prevents 2,900 MARCE events. The annual budget impact was an estimated saving of $30.71 million, aggregated across all US hospitals, $6,316 per hospital, or $60 per procedure. Net savings were maintained across all univariate sensitivity analyses. While MARCE/event-free cost differential was the most important factor driving total net savings for hospitals in the Northeast and West, procedural volume was important in the Midwest and rural locations.

CONCLUSIONS

Switching to an "IOCM only" strategy from a "LOCM only" approach yields substantial net global savings to hospitals, both at the national level and within hospital sub-groups. Hospital administrators should maintain awareness of the factors that are likely to be more influential for their hospital and recognize that purchasing on the basis of lower contrast media cost may result in higher overall costs for patients undergoing inpatient angioplasty.

The Burden of Acute Kidney Injury and Related Financial Issues

BACKGROUND

Acute kidney injury (AKI) is one of the most common complications in acutely ill patients. The epidemiology, clinical presentation, and outcome vary between patients and countries.

SUMMARY

Patients with AKI often exhibit multiple organ dysfunction that is caused, in part, by marked cross-talk between the kidney and other organs and tissues. These deleterious interactions arise, at least in part, from systemic inflammatory changes, an increased cytokine load, increases in leukocyte trafficking and activation of neurohormonal processes. Typical short-term complications of AKI include acute lung injury, liver dysfunction, cardio-renal syndrome, brain dysfunction, systemic inflammation, and increased mortality. Survivors of AKI are at risk of chronic kidney disease, cardiovascular morbidity, strokes, infections, bone fractures and increased mortality. AKI is associated with high healthcare costs as a result of a longer stay in hospital, increased costs for investigations and interventions and the development of long-term complications including dialysis dependence, chronic comorbidities and re-hospitalisations. The outcomes and financial implications are worse in low-income countries compared to high-income countries. Key Message: AKI is common among hospitalised patients and associated with serious short- and long-term complications, increased mortality, and high health care costs. There are important differences in epidemiology and outcomes between low- and high-income countries.

Health Care Costs Associated with AKI

BACKGROUND AND OBJECTIVES

An understanding of the health care resource use associated with AKI is needed to frame the investment and cost-effectiveness of strategies to prevent AKI and promote kidney recovery.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We assembled population-based cohort of adults hospitalized in Alberta between November of 2002 and March of 2009 without ESRD or an eGFR<15 ml/min per 1.73 m2. Outpatient serum creatinine measurements 6 months preceding admission defined baseline kidney function, and serum creatinine during the first 14 days of hospitalization defined Acute Kidney Injury Network stage; kidney recovery defined as serum creatinine within 25% of baseline and independence from dialysis was assessed at 90 days after AKI. Health care utilization and costs (in 2015 Canadian dollars) were determined from inpatient, outpatient, and physician claims datasets during the index hospitalization, recovery period (90 days post-AKI assessment), and 3-12 months post-AKI. A fully adjusted generalized linear model regression analysis was used to estimate costs associated with AKI.

RESULTS

Of 239,906 hospitalized subjects, 25,495 (10.6%), 4598 (1.9%), 2493 (1.0%), and 670 (0.3%) had Acute Kidney Injury Network stages 1, 2, 3 without dialysis, and 3 with dialysis, respectively. Greater severity of AKI was associated with incremental increases in length of stay (+2.8; 95% confidence interval, 1.4 to 4.3 to +7.4; 95% confidence interval, 7.2 to 7.5 days) and costs (+$3779; 95% confidence interval, $3555 to $4004 to +$18,291; 95% confidence interval, $15,573 to $21,009 Canadian dollars) from admission to recovery assessment (3 months). At months 3-12 postadmission, compared with subjects without AKI, AKI with kidney recovery and AKI without kidney recovery were associated with incremental costs of +$2912-$3231 and +$6035-$8563 Canadian dollars, respectively. The estimated incremental cost of AKI in Canada is estimated to be over $200 million Canadian dollars per year.

CONCLUSIONS

Severity of AKI, need for dialysis, and lack of kidney recovery are associated with significant health care costs in hospitalized patients and persist a year after admission. Strategies to identify, prevent, and facilitate kidney recovery are needed.

Mortality and cost of acute and chronic kidney disease after cardiac surgery

PURPOSE OF REVIEW

Acute and chronic kidney diseases (AKI and CKD) have far-reaching implications for surgical patients in regards to postoperative outcomes and hospital cost. We review the recent literature on the effects of AKI and CKD on morbidity, mortality, and resource utilization among cardiac surgery patients.

RECENT FINDINGS

Both AKI and CKD increase the risk for short-term and long-term mortalities, morbidity, length of stay, and hospital cost among postoperative patients, with increasing disease stage correlating with worse outcomes. Even the mildest forms of AKI (RIFLE-R) and CKD (proteinuria without an observed reduction in estimated glomerular filtration rate) demonstrate worse clinical outcomes compared with patients with no AKI or CKD. Outcomes are worse even in patients who achieve full renal recovery before hospital discharge. These complications dramatically increase ICU length of stay, hospital length of stay, resource utilization, and both in-hospital and postdischarge costs, as evidenced by lower rates of discharges to home.

SUMMARY

AKI and CKD remain prevalent, morbid, and costly conditions for cardiac surgery patients. Better risk stratification, early diagnosis, and earlier interventions are needed to prevent the consequences of these diseases.

Pre-Stage Acute Kidney Injury Can Predict Mortality and Medical Costs in Hospitalized Patients

The significance of minimal increases in serum creatinine below the levels indicative of the acute kidney injury (AKI) stage is not well established. We aimed to investigate the influence of pre-stage AKI (pre-AKI) on clinical outcomes. We enrolled a total of 21,261 patients who were admitted to the Seoul National University Bundang Hospital from January 1, 2013 to December 31, 2013. Pre-AKI was defined as a 25–50% increase in peak serum creatinine levels from baseline levels during the hospital stay. In total, 5.4% of the patients had pre-AKI during admission. The patients with pre-AKI were predominantly female (55.0%) and had a lower body weight and lower baseline levels of serum creatinine (0.63 ± 0.18 mg/dl) than the patients with AKI and the patients without AKI (P < 0.001). The patients with pre-AKI had a higher prevalence of diabetes mellitus (25.1%) and malignancy (32.6%). The adjusted hazard ratio of in-hospital mortality for pre-AKI was 2.112 [95% confidence interval (CI), 1.143 to 3.903]. In addition, patients with pre-AKI had an increased length of stay (7.7 ± 9.7 days in patients without AKI, 11.4 ± 11.4 days in patients with pre-AKI, P < 0.001) and increased medical costs (4,061 ± 4,318 USD in patients without AKI, 4,966 ± 5,099 USD in patients with pre-AKI, P < 0.001) during admission. The adjusted hazard ratio of all-cause mortality for pre-AKI during the follow-up period of 2.0 ± 0.6 years was 1.473 (95% CI, 1.228 to 1.684). Although the adjusted hazard ratio of pre-AKI for overall mortality was not significant among the patients admitted to the surgery department or who underwent surgery, pre-AKI was significantly associated with mortality among the non-surgical patients (adjusted HR 1.542 [95% CI, 1.330 to 1.787]) and the patients admitted to the medical department (adjusted HR 1.384 [95% CI, 1.153 to 1.662]). Pre-AKI is associated with increased mortality, longer hospital stay, and increased medical costs during admission. More attention should be paid to the clinical significance of pre-AKI.

Medicare Program; End-Stage Renal Disease Prospective Payment System, Coverage and Payment for Renal Dialysis Services Furnished to Individuals With Acute Kidney Injury, End-Stage Renal Disease Quality Incentive Program, Durable Medical Equipment, Prosthetics, Orthotics and Supplies Competitive Bidding Program Bid Surety Bonds, State Licensure and Appeals Process for Breach of Contract Actions, Durable Medical Equipment, Prosthetics, Orthotics and Supplies Competitive Bidding Program and Fee Schedule Adjustments, Access to Care Issues for Durable Medical Equipment; and the Comprehensive End-Stage Renal Disease Care Model. Final rule

This rule updates and makes revisions to the End-Stage Renal Disease (ESRD) Prospective Payment System (PPS) for calendar year 2017. It also finalizes policies for coverage and payment for renal dialysis services furnished by an ESRD facility to individuals with acute kidney injury. This rule also sets forth requirements for the ESRD Quality Incentive Program, including the inclusion of new quality measures beginning with payment year (PY) 2020 and provides updates to programmatic policies for the PY 2018 and PY 2019 ESRD QIP. This rule also implements statutory requirements for bid surety bonds and state licensure for the Durable Medical Equipment, Prosthetics, Orthotics, and Supplies (DMEPOS) Competitive Bidding Program (CBP). This rule also expands suppliers' appeal rights in the event of a breach of contract action taken by CMS, by revising the appeals regulation to extend the appeals process to all types of actions taken by CMS for a supplier's breach of contract, rather than limit an appeal for the termination of a competitive bidding contract. The rule also finalizes changes to the methodologies for adjusting fee schedule amounts for DMEPOS using information from CBPs and for submitting bids and establishing single payment amounts under the CBPs for certain groupings of similar items with different features to address price inversions. Final changes also are made to the method for establishing bid limits for items under the DMEPOS CBPs. In addition, this rule summarizes comments on the impacts of coordinating Medicare and Medicaid Durable Medical Equipment for dually eligible beneficiaries. Finally, this rule also summarizes comments received in response to a request for information related to the Comprehensive ESRD Care Model and future payment models affecting renal care.

Cost of Critically Ill Surgical Patients in Thailand: A Prospective Analysis of a Multicenter THAI-SICU Study

OBJECTIVE

To quantify the total cost per admission and daily cost of critically ill surgical patients and cost attributable to Acute Physiologic Assessment and Chronic Health Evaluation (APACHE) II score, invasive mechanical ventilation and major complications in surgical intensive care unit (SICU) including sepsis, acute respiratory distress syndrome (ARDS), acute lung injury (ALI), acute kidney injury (AKI), cardiac arrest, and myocardial infarction.

MATERIAL AND METHOD

A multicentre, prospective, observational, cost analysis study was carried out in SICU of five university hospitals in Thailand. Patients of age over 18 admitted to SICU (more than 6 hours) from 18 April 2011 to 30 November 2012 were recruited.The total SICU cost per admission (in Thai baht currency year 2011-2012) were recorded using hospital accounting database. Average daily SICU cost was calculated from total ICU cost divided by the ICU length of stay. The occurrence of sepsis, major cardiac and respiratory complications and duration of invasive mechanical ventilation were studied.

RESULTS

A total of 3,055 patients with 12,592 ICU-days admitted to SICU during the study period. The median (IQR) ICU- length of stay was 2 (1, 4) days. The median (IQR) total SICU cost per admission was 44,055 (29,950-73,694) Thai baht. The median (IQR) daily cost was 18,777 (13,650-22,790) Thai baht. There was a variation of total and daily SICU cost across ICUs. For each of APACHE II score increases, cost increases with a median (IQR) of 1,731.755 (1,507.418-1,956.093) Thai baht. Invasive mechanically ventilated patients had higher cost than non-ventilated patients with a median (IQR) 15,873.4 (15,631.13-16,115.67) Thai baht. The patient with any complications listed here (sepsis, ARDS, ALI, AKI, myocardial infarction) had higher costs of care than ones who had none.

CONCLUSION

Cost of critically ill surgical patients in the public university hospital in Thailand was varied. The complications occurred in ICU increased the cost. To quantify the resource consumption of individual patient admitted to SICU, the costing method and cost components must be verified.

Acute Kidney Outreach to Reduce Deterioration and Death (AKORDD) trial: the protocol for a large pilot study

INTRODUCTION

Acute kidney injury (AKI) contributes to morbidity and mortality, and its care is often suboptimal and/or delayed. The Acute Kidney Outreach to Reduce Deterioration and Death (AKORDD) study is a large pilot testing provision of early specialist advice, to improve outcomes for patients with AKI.

METHODS AND ANALYSIS

This before and after study will test an Outreach service for adult patients with AKI, identified using the national algorithm. During the 2-month before phase, AKI outcomes (30-day mortality, need for dialysis or AKI stage deterioration) will be observed in the intervention and control hospitals and their respective community areas; no interventions will be delivered. Patients will receive good standard care. During the 5-month after phase, the intervention will be delivered to patients with AKI in the intervention hospital and its area. Patients with AKI in the control hospital and its area will continue to have good standard care only. Patients already on dialysis and at end of life will be excluded. The interventions will be initially delivered via a phone call, with or without a visit to the primary clinician, aiming at rapidly establishing the aetiology, correcting reversible causes and conducting further appropriate investigation. Surviving stage 3 patients will be followed-up in an AKI clinic. We will conduct qualitative research using focus group-based discussions with primary and secondary care clinicians during the early and late phases of the trial. This will help break down potential barriers and improve care delivery.

ETHICS AND DISSEMINATION

Patients will be contacted about the study allowing them to 'opt out'. The work of an Outreach team, guided by AKI alerts and delivering timely advice to clinicians, may improve outcomes. If the results suggest that benefits are delivered by an AKI Outreach team, this study will lead to a full cluster randomised trial.

TRIAL REGISTRATION NUMBER

NCT02398682: Pre-results.

[Geriatric nephrology: an overview]

INTRODUCTION

Chronic kidney disease (CKD) is a highly prevalent condition and its prevalence is increasing worldwide, particularly in adults aged 70 years. Epidemiological studies showed that as many as 2054% of the older adults suffer from CKD in stages 3-5. Nevertheless the question whether this lower eGFR is a consequence of kidney disease or if it is the result of a physiological aging is still debated, even if it implies a reduced renal reserve and vulnerability to drugs overdose with increased risk of acute kidney injury (AKI).

MATERIALS AND METHODS

PubMed search was conducted for available English literature, describing the actual knowledge about specific and frequent issues reported in the acute and chronic kidney disease in older adults. Prospective and retrospective studies, as well as meta-analyses and latest systematic reviews were included.

RESULTS

Most of the studies examined and reviewed were discarded for wrong population or intervention or deemed unfit. Only 103 met the inclusion criteria for the review. The studies included in the review were grouped into two areas: chronic and acute kidney disease in older adults and we have analysed the peculiar and frequently found issues in this population.

CONCLUSIONS

The geriatric population is increasing worldwide. We should consider peculiar aspects of this population, such as sarcopenia, malnutrition, psychological and cognitive deficits and increased risk of AKI, in order to reach a good quality of life, with improved doctor / patient relationship, a greater adherence to therapy, a reduction in health care costs, and if possible, adequate "end of life", as far as it is approved by the patient and his family. The achievement of these objectives requires an organized work in multidisciplinary teams that evaluate overall the geriatric patient.

Economics of dialysis dependence following renal replacement therapy for critically ill acute kidney injury patients

BACKGROUND

The obective of this study was to perform a cost-effectiveness analysis comparing intermittent with continuous renal replacement therapy (IRRT versus CRRT) as initial therapy for acute kidney injury (AKI) in the intensive care unit (ICU).

METHODS

Assuming some patients would potentially be eligible for either modality, we modeled life year gained, the quality-adjusted life years (QALYs) and healthcare costs for a cohort of 1000 IRRT patients and a cohort of 1000 CRRT patients. We used a 1-year, 5-year and a lifetime horizon. A Markov model with two health states for AKI survivors was designed: dialysis dependence and dialysis independence. We applied Weibull regression from published estimates to fit survival curves for CRRT and IRRT patients and to fit the proportion of dialysis dependence among CRRT and IRRT survivors. We then applied a risk ratio reported in a large retrospective cohort study to the fitted CRRT estimates in order to determine the proportion of dialysis dependence for IRRT survivors. We conducted sensitivity analyses based on a range of differences for daily implementation cost between CRRT and IRRT (base case: CRRT day $632 more expensive than IRRT day; range from $200 to $1000) and a range of risk ratios for dialysis dependence for CRRT as compared with IRRT (from 0.65 to 0.95; base case: 0.80).

RESULTS

Continuous renal replacement therapy was associated with a marginally greater gain in QALY as compared with IRRT (1.093 versus 1.078). Despite higher upfront costs for CRRT in the ICU ($4046 for CRRT versus $1423 for IRRT in average), the 5-year total cost including the cost of dialysis dependence was lower for CRRT ($37 780 for CRRT versus $39 448 for IRRT on average). The base case incremental cost-effectiveness analysis showed that CRRT dominated IRRT. This dominance was confirmed by extensive sensitivity analysis.

CONCLUSIONS

Initial CRRT is cost-effective compared with initial IRRT by reducing the rate of long-term dialysis dependence among critically ill AKI survivors.

World incidence of AKI: a meta-analysis

BACKGROUND AND OBJECTIVES

The burden of AKI around the globe has not been systematically examined.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

A systematic review (2004-2012) of large cohort studies was conducted to estimate the world incidence of AKI and its stages of severity and associated mortality, and to describe geographic variations according to countries, regions, and their economies. AKI definitions were reclassified according to the Kidney Disease Improving Global Outcomes (KDIGO) staging system. Random-effects model meta-analyses and meta-regressions were used to generate summary estimates and explore sources of heterogeneity.

RESULTS

There were 312 studies identified (n=49,147,878) , primarily in hospital settings. Most studies originated from North America, Northern Europe, and Eastern Asia, from high-income countries, and from nations that spent ≥5% of the gross domestic product on total health expenditure. Among the 154 studies (n=3,585,911) that adopted a KDIGO-equivalent AKI definition, the pooled incidence rates of AKI were 21.6% in adults (95% confidence interval [95% CI], 19.3 to 24.1) and 33.7% in children (95% CI, 26.9 to 41.3). The pooled AKI-associated mortality rates were 23.9% in adults (95% CI, 22.1 to 25.7) and 13.8% in children (95% CI, 8.8 to 21.0). The AKI-associated mortality rate declined over time, and was inversely related to income of countries and percentage of gross domestic product spent on total health expenditure.

CONCLUSIONS

Using the KDIGO definition, 1 in 5 adults and 1 in 3 children worldwide experience AKI during a hospital episode of care. This analysis provides a platform to raise awareness of AKI with the public, government officials, and health care professionals.

[Urinary L-type fatty acid binding protein (L-FABP) as a new urinary biomarker promulgated by the Ministry of Health, Labour and Welfare in Japan]

Liver-type fatty acid binding protein (L-FABP) is a 14kDa protein found in the cytoplasm of human renal proximal tubules. Fatty acids are bound with L-FABP and transported to the mitochondria or peroxisomes, where fatty acids are beta-oxidized, and this may play a role in fatty acid homeostasis. Moreover, L-FABP has high affinity and capacity to bind long-chain fatty acid oxidation products, and may be an effective endogenous antioxidant. Renal L-FABP is rarely expressed in the kidneys of rodents. In order to evaluate the pathological dynamics of renal L-FABP in kidney disease, human L-FABP chromosomal transgenic mice were generated. Various stress, such as massive proteinuria, hyperglycemia, hypertension, and toxins overloaded in the proximal tubules were revealed to up-regulate the gene expression of renal L-FABP and increase the excretion of L-FABP derived from the proximal tubules into urine. In clinical studies of chronic kidney disease (CKD), urinary L-FABP accurately reflected the degree of tubulointerstitial damage and correlated with the rate of CKD progression. Furthermore, a multicenter trial has shown that urinary L-FABP is more sensitive than urinary protein in predicting the progression of CKD. With respect to diabetic nephropathy and acute kidney disease (AKI), urinary L-FABP is an early diagnostic of kidney disease or a predictive marker for renal prognosis. After many clinical studies, urinary L-FABP was approved as a new tubular biomarker promulgated by the Ministry of Health, Labour and Welfare in Japan.

Membrane designs and composition for hemodialysis, hemofiltration and hemodialfiltration: past, present and future

Today hemodialysis is a routine outpatient treatment, not only carried out in hospitals, but more commonly in free standing units without on site medical supervision. One of the key advances that have underpinned this expansion of hemodialysis provision has been the technological advances in dialyzer membrane technology. Dialyzer membranes have undergone a sea change from collodion tubes to cellulose sheets to the modern day capillary fiber dialyzer. Improvements have not only been limited to reliability of manufacture, but also reduction in bio-incompatibility, and improved small solute clearances. However, the holy Grail remains the development of a dialyzer capable of removing middle sized azotemic retention solutes, and protein bound or lipophilic solutes.

The long-term prognosis of acute kidney injury: acute renal failure as a cause of chronic kidney disease

There is a widespread opinion that acute kidney injury (AKI) is a rather harmless complication and that survival is determined not by renal dysfunction per se, but by the severity of the underlying disease. This opinion is in sharp contrast to evidence from several recent experimental and clinical investigations indicating that AKI is a condition which exerts a fundamental impact on the course of the disease, the evolution of associated complications and on prognosis, independently from the type and severity of the underlying condition. In conclusion, severe AKI in the critically ill patient is associated with high rates of morbidity, mortality and consumption of health care resources.

Patient flow from critical care to renal services: a year-long survey in a critical care network

BACKGROUND

The NSF for Renal Services stresses the importance of collaboration between renal services and critical care networks in managing patients with acute renal failure in the most clinically appropriate setting. Anecdotal evidence in our region suggested that some patients were remaining on critical care inappropriately because of a lack of capacity for step-down care in local renal units.

AIM

To determine the number of extra days patients spend on critical care receiving single-organ renal support before transfer to a renal unit.

DESIGN

Prospective, multi-centre, service evaluation.

METHODS

Prospective data were collected over a one-year period by either daily telephone calls or bedside review. Follow-up data were retrieved from electronic and patient records.

RESULTS

Five hundred and forty-two patients received renal replacement therapy (RRT) in critical care. With 68 (12.5%) patients already receiving RRT for end-stage renal failure, this gave an incidence of new RRT on critical care of 234 per million population per year. The median duration of RRT on critical care was 4 days (range 1-30). One hundred and twenty-seven patients (23%) were discharged from critical care still requiring RRT. A period of single-organ renal support (median 2 days, range 1-8) was provided to 74 of these patients (58%) using 113 critical care bed days.

DISCUSSION

Over half of patients receiving RRT on discharge from critical care in our network received a short period of single-organ renal support before step-down. This may represent either delayed discharge from critical care or a potential opportunity for care in an alternative high-dependency facility.

Long-term outcome after acute kidney injury in critically-ill patients

Assessment of short-term outcome in critically-ill patients who develop acute kidney injury (AKI) may underestimate the true burden of disease. It is important to focus on long-term survival, renal recovery and quality of life beyond hospital discharge. Although the majority of critically-ill patients with AKI die during hospital stay, there is only a minor increase in mortality after hospital discharge among AKI patients treated in the intensive care unit (ICU). Estimates of mortality rates at 1 year following hospital discharge range from 57% to 78% with an absolute difference between hospital mortality and 1-year mortality ranging from 4% to 18%. Renal recovery is another important measure of outcome since chronic renal replacement therapy (RRT) does not only significantly affect health-related quality of life (HRQoL), it is also costly. Fortunately, renal recovery occurs in most AKI survivors leading to independence of RRT at 1 year following hospital discharge. Potential factors associated with reduced recovery of renal function are female sex, high comorbidity, older age, a parenchymal aetiology of AKI, late initiation of RRT, and use of intermittent haemodialysis (IHD). HRQoL in survivors of critical illness and severe AKI is perceived as acceptable and good, despite the fact that HRQoL scores are lower than these of the general population.

Acute kidney injury, length of stay, and costs in patients hospitalized in the intensive care unit

Acute kidney injury (AKI) in patients hospitalized in the intensive care unit (ICU) results in increased morbidity, mortality, and as a consequence, higher health-care costs. The bad prognosis associated with this condition and limited health-care budgets both have raised the issue of how much therapy should be dedicated to ICU patients with AKI. As no universally-agreed standardized definition for AKI is available, wide ranges of incidence are reported and precise estimates of its associated excess of costs are, therefore, difficult to explore. Nonetheless, significantly prolonged hospital length of stay (LOS) and higher costs in ICU patients whose course was complicated with AKI are reported. Moreover, among survivors, even greater requirements of in-hospital and post-hospitalization care was noted. Notwithstanding the high health-economic burden, full supportive intensive care treatment is justified in this particular cohort of patients. Major efforts are highly required in terms of public health prevention initiatives and the early recognition and timely management of AKI, in ICU hospitalized patients in particular.

Costs and length of stay associated with antimicrobial resistance in acute kidney injury patients with bloodstream infection

INTRODUCTION

Antimicrobial resistance negatively impacts on prognosis. Intensive care unit (ICU) patients, and particularly those with acute kidney injury (AKI), are at high risk for developing nosocomial bloodstream infections (BSI) due to multi-drug-resistant strains. Economic implications in terms of costs and length of stay (LOS) attributable to antimicrobial resistance are underevaluated. This study aimed to assess whether microbial susceptibility patterns affect costs and LOS in a well-defined cohort of ICU patients with AKI undergoing renal replacement therapy (RRT) who developed nosocomial BSI.

METHODS

Historical study (1995-2004) enrolling all adult RRT-dependent ICU patients with AKI and nosocomial BSI. Costs were considered as invoiced in the Belgian reimbursement system, and LOS was used as a surrogate marker for hospital resource allocation.

RESULTS

Of the 1330 patients with AKI undergoing RRT, 92 had microbiologic evidence of nosocomial BSI (57/92, 62% due to a multi-drug-resistant microorganism). Main patient characteristics were equal in both groups. As compared to patients with antimicro-4 bial-susceptible BSI, patients with antimicrobial-resistant BSI were more likely to acquire Gram-positive infection (72.6% vs 25.5%, P<0.001). No differences were found neither in LOS (ICU before BSI, ICU, hospital before BSI, hospital, hospital after BSI, and time on RRT; all P>0.05) or hospital costs (all P>0.05) when comparing patients with antimicrobial-resistant vs antimicrobial-susceptible BSI. However, although not statistically significant, patients with BSI caused by resistant Gram-negative-, Candida-, or anaerobic bacteria incurred substantial higher costs than those without.

CONCLUSION

In a cohort of ICU patients with AKI and nosocomial BSI undergoing RRT, patients with antimicrobial-resistant vs antimicrobial-susceptible Gram-positive BSI did not have longer hospital stays, or higher hospital costs. Patients with resistant "other" (i.e. Gram-negative, Candida, or anaerobic) BSI were found to have a distinct trend towards increased resources use as compared to patients with susceptible "other" BSI, respectively.

Renal dysfunction in trauma: even a little costs a lot

BACKGROUND

Acute renal failure (ARF) is a devastating complication in critically ill patients. There is a paucity of data that describes the impact of ARF on the outcome of trauma patients admitted to the intensive care unit.

METHODS

We studied trauma patients admitted to the surgical intensive care unit to determine the effect of increases in serum creatinine on the number of ventilator days, length of stay, mortality, and cost. We used the administrative database of the hospital and the trauma registry. Renal failure (RF) was defined as one or more of the following: creatinine >1.5 mg/dL, increase in creatinine of >50%, or increase of creatinine by 0.5 mg/dL.

RESULTS

We obtained data on 1,033 patients. Two hundred and forty-six (23.8%) patients met at least one criterion for RF. Only 25 of these patients had one or more episodes of renal replacement therapy. The RF group had mortality of 24.4% compared with 2.3% in the no renal failure group (p < 0.0001). For each 1 mg/dL increase from the initial creatinine, length of stay increased by 2.21 days, ventilator days increased by 1.09 days, and the mortality risk increased by 1.83 times (CI, 1.47-2.29; p < 0.0001). For any diagnosis of renal dysfunction, the average cost increase was $3,088.00 and increased mortality risk was 7.19 times (CI, 4.11-12.58).

CONCLUSION

Vigilance in preventing creatinine increases and ameliorating or removing potential causes should occur as soon as creatinine begins to rise to avoid worsening renal function, to reduce cost, and to improve patient outcome.

Cardiopulmonary bypass-associated acute kidney injury: a pigment nephropathy?

Acute kidney injury (AKI) is a common and serious postoperative complication following exposure to cardiopulmonary bypass (CPB). Several mechanisms have been proposed by which the kidney can be damaged and interventional studies addressing known targets of renal injury have been undertaken in an attempt to prevent or attenuate CPB-associated AKI. However, no definitive strategy appears to protect a broad heterogeneous population of cardiac surgery patients from CPB-associated AKI. Although the association between hemoglobinuria and the development of AKI was recognized many years ago, this idea has not been sufficiently acknowledged in past and current clinical research in the context of cardiac surgery-related AKI. Hemoglobin-induced renal injury may be a major contributor to CPB-associated AKI. Accordingly, we now describe in detail the mechanisms by which hemoglobinuria may induce renal injury and raise the question as to whether CPB-associated AKI may actually be, in a significant part, a form of pigment nephropathy where hemoglobin is the pigment responsible for renal injury. If CPB-associated AKI is a pigment nephropathy, alkalinization of urine with sodium bicarbonate might protect from: (1) tubular cast formation from met-hemoglobin; (2) proximal tubular cell necrosis by reduced endocytotic hemoglobin uptake, and (3) free iron-mediated radical oxygen species production and related injury. Sodium bicarbonate is safe, simple to administer and inexpensive. If part of AKI after CPB is truly secondary to hemoglobin-induced pigment nephropathy, prophylactic sodium bicarbonate infusion might help attenuate it. A trial of such treatment might be a reasonable future investigation in higher risk patients receiving CPB.

Invasive aspergillosis: is treatment with "inexpensive" amphotericin B cost saving if "expensive" voriconazole is only used on demand?

BACKGROUND

Voriconazole for the treatment of invasive aspergillosis (IA) shows superior clinical outcome and tolerability compared to conventional amphotericin B. However, the latter is often used as initial treatment due to lower drug acquisition costs. Therefore we performed a cost-effectiveness analysis.

METHODS

A decision analytic model was designed to compare the cost-effectiveness of a regimen of voriconazole followed by conventional amphotericin B to a regimen of conventional amphotericin B followed by voriconazole. Patients initiated on treatment either completed initial therapy or switched to second line therapy due to toxicity or non-response. Probability of a switch was based on clinical trial data and local rates of renal toxicity. Resource use in the hospital was taken from the Global Comparative Aspergillosis (GCA) study. Costs were based on local drug acquisition costs, local cost estimates for hospitalisation and adjusted additional costs of amphotericin B-induced acute renal failure from the literature. Effectiveness was defined as survival at 12 weeks from the GCA study. An incremental cost-effectiveness ratio was estimated as the incremental cost per life saved comparing voriconazole to conventional amphotericin B.

RESULTS

Based on this model, initial therapy of IA with voriconazole reduced total costs when compared to initial therapy with conventional amphotericin B (CHF 37 878/patient vs CHF 49 861/patient) and resulted in better survival at 12 weeks, making it the dominant treatment in terms of incremental cost-effectiveness. Results were most sensitive to alternative assumptions of the incidence of acute renal failure, but cost savings were sustained for voriconazole over a wide range of values.

CONCLUSION

Considering that initial therapy with voriconazole is both cost-saving and results in better clinical outcomes, voriconazole is the dominant cost-effective option for initial therapy of IA, despite very low drug acquisition costs of conventional amphotericin B.

[Renal replacement therapies in intensive care units: cost analysis]

The medical treatment of intensive care unit patients represents one of the greatest costs in the health care system. Patients affected by acute renal failure account for about -10% of cases: dialysis treatment is of major importance in an economical setting. Recent studies compared continuous renal replacement therapy (CRRT) with intermittent hemodialysis (IHD). Cost comparison of the two methods showed that CRR is more expensive due to the technical device costs, while the intermittent dialysis costs depended mostly on human resources management, e.g. a longer time spent for nurse and hemodyalisis surveillance. Moreover, a higher dialysis dose, easily obtained with CRRT, could improve survival and renal function recovery leading to a reduction in hospitalization and consequently minor health care costs. These parameters, if opportunely evaluated and verified through randomized multicentric trials, could lead to an economical balance between CRRT and IHD; nephrologists, then, could choose a method out of medical and clinical more than economic reasons.

Uncomplicated acute renal failure and hospital resource utilization: a retrospective multicenter analysis

BACKGROUND

Although acute renal failure (ARF) complicating nonrenal organ dysfunction in the intensive care unit is associated with significant mortality and hospital costs, hospital resource utilization attributed to uncomplicated ARF is not well known. The goal of this study is to characterize the costs and lengths of stay (LOSs) incurred by hospitalized patients with uncomplicated ARF and their important determining factors.

METHODS

We obtained hospital case-mix data sets from 23 Massachusetts hospitals for a 2-year period (1999 to 2000) from the Massachusetts Division of Health Care Finance and Policy. A total of 2,252 records of patients hospitalized with uncomplicated ARF were identified. Patient records of other common medical diagnoses were studied for comparison.

RESULTS

Patients hospitalized with uncomplicated ARF incurred median direct hospital costs of 2,600 dollars, median hospital LOS of 5 days, and mortality of 8%. Dialysis was independently associated with significantly greater hospital costs and LOSs for patients with uncomplicated ARF (P < 0.05). Male sex and nonwhite race were associated with significantly lower hospital costs and LOSs, whereas type of hospital had opposing effects on these 2 resource utilization outcomes (P < 0.05). Unadjusted aggregate resource utilization associated with uncomplicated ARF exceeded that of many other common illnesses.

CONCLUSION

Demographic and hospital factors, as well as dialysis therapy, are significant determinants of hospital resource utilization for patients with uncomplicated ARF. Uncomplicated ARF appears to incur greater hospital costs and longer LOSs compared with other common medical conditions. Greater focus should be directed toward further understanding of the factors influencing resource utilization for ARF.

Cardiovascular prophylaxis with aspirin: costs of supply and management of upper gastrointestinal and renal toxicity

AIMS

To determine the cost to the NHS of prescribed low-dose aspirin.

METHODS

This was a population based observational cohort study. Patients from Tayside Scotland (17 244 new users of dispensed aspirin each with 10 matched comparators) were included. A pragmatic analysis totalled costs from the start to end of the study and compared these with a matched cohort of aspirin nonusers to estimate excess costs. Fastidious analyses were done of subjects with no prior history of upper gastrointestinal (UGI) or renal disease where the cost that occurred during aspirin exposure, the 30 days following aspirin exposure and subsequent nonexposure was calculated adjusting for risk factors in each period.

RESULTS

Subjects took aspirin for only 1.18 of the 2.53 years follow-up (47% compliance). Aspirin use cost an additional 49.86 UK pounds per year (pragmatic analysis) made up of 1.96 UK pounds for aspirin tablets (4%), 5.49 UK pounds for dispensing costs (11%), 24.60 UK pounds for UGI complications (49%) and 17.81 UK pounds for renal complications (36%). The costs for managing complications were substantially lower in the fastidious analysis (2.66 UK pounds for UGI complications and 2.92 UK pounds for renal complications). Assuming that the antiplatelet trial meta-analysis is an accurate assessment of the benefits of aspirin, the costs of preventing one vascular event lay between 62 500 UK pounds (primary prevention, pragmatic analysis) and 867 UK pounds (secondary prevention, fastidious analysis). These costs may be underestimates due to the low compliance observed.

CONCLUSIONS

Compliance with aspirin was poor. Serious adverse events were uncommon but despite this aspirin cost the NHS between 6 and 25 times the cost of aspirin tablets due to dispensing costs and the cost of managing adverse effects.

Cost analysis of blood purification in intensive care units: continuous versus intermittent hemodiafiltration

BACKGROUND

We implemented a program for continuous renal replacement therapies (CRRT) in intensive care units (ICU) based on the cooperative work of dialysis and ICU personnel. Our aim was to report the main details of this program and compare its cost with that of intermittent hemodiafiltration (IHDF).

METHODS

The study referred to 181 ICU patients with renal failure. We considered the costs of both technical devices and assisting personnel. CRRT was performed as continuous veno-venous hemodiafiltration (CVVHDF) (24 hr daily); dialysis and ICU nurses shared surveillance. Only dialysis nurses performed IHDF (as acetate-free biofiltration, 4 hr daily) in the ICU.

RESULTS

The daily cost of CRRT was Euro 276.70; of which 79% was for devices and 21% was for human resources. Nurse surveillance required 141 min per day, ICU nurses supplied 55% (77 min) and dialysis nurses 45% (64 min). On average, CRRT surveillance required less than 1 min/nurse/hr for both dialysis and ICU nurses. The daily cost of 4-hr IHDF sessions of was Euro 247.83, of which 44% was for technical devices and 56% was for human resources.

CONCLUSIONS

The cooperation between dialysis and ICUs improved the use of human resources and allowed us to supply CRRT to all critically ill patients with acute renal failure. The expenditure for CRRT was 12% higher than that for IHDF, due to the cost of technical devices.

Cost of acute renal failure requiring dialysis in the intensive care unit: clinical and resource implications of renal recovery

OBJECTIVE

Acute renal failure can be treated with continuous renal replacement therapy (CRRT) or intermittent hemodialysis. There is no difference in mortality, although patients treated with CRRT may have a higher rate of renal recovery. Given these considerations, an estimate of the costs by modality may help in choosing the method of dialysis. As such, the objective of this study was to estimate the cost of CRRT and intermittent hemodialysis in the intensive care unit and to explore the impact of renal recovery on subsequent clinical outcomes and costs among survivors.

DESIGN

Retrospective cohort study of all patients who developed acute renal failure and required dialysis between April 1, 1996, and March 31, 1999.

SETTING

Two tertiary care intensive care units in Calgary, Canada.

PATIENTS

A total of 261 critically ill patients.

INTERVENTIONS

None.

MEASUREMENTS

All patients were followed to determine in-hospital and subsequent clinical outcomes (survival and frequency of renal recovery). The immediate and potential long-term costs of CRRT and intermittent hemodialysis were measured.

MAIN RESULTS

The cost of performing CRRT ranged from Can 3,486 dollars to Can 5,117 dollars per week, depending on the modality and the anticoagulant used, and it was significantly more expensive than intermittent hemodialysis (Can 1,342 dollars per week). Survivors with renal recovery spent significantly fewer days in hospital (11.3 vs. 22.5 days, p<.001) and incurred less healthcare costs (11,192 dollars vs. 73,273 dollars, p<.001) over the year after hospital discharge compared with survivors who remained on dialysis.

CONCLUSIONS

Immediate cost savings could be achieved by increasing the use of intermittent hemodialysis rather than CRRT for patients with acute renal failure in the intensive care unit. Because of the high cost of ongoing dialysis, CRRT may still be an economically efficient treatment if it improves renal recovery among survivors; further study in this area is required.

Selection of endpoints for clinical trials of acute renal failure in critically ill patients

The selection of appropriate outcome measures is essential to the design of clinical trials of the prevention or treatment of acute renal failure in critically ill patients. In this paper, we present the consensus opinion from the second Acute Dialysis Quality Initiative Conference held in Vicenza, Italy, in May 2002, regarding the issues that should guide the selection of endpoints in clinical intervention trials of acute renal failure. Important criteria for the selection of these outcome measures include their clinical importance, responsiveness to experimental intervention, precision of definition, accuracy of measurement, and completeness of ascertainment. Although the most appropriate endpoints for individual studies are dependent on specific hypotheses and study designs, the primary endpoint in prevention trials should be based on an assessment of renal function, whereas mortality or renal functional assessment may serve as the primary endpoint in studies of established acute renal failure.

Acute renal failure in hospitalized patients: part I

BACKGROUND

Acute renal failure (ARF) is a common condition in hospitalized patients. Morbidity, mortality, and health resource use are considerable, but the true magnitude of the problem is not well described in the literature.

OBJECTIVE

To provide a detailed discussion of the epidemiology, economic costs, and classification of ARF.

DATA SOURCES

A MEDLINE search (1996-December 2001) was conducted using the search terms kidney and acute kidney failure: epidemiology, etiology, and drug therapy/drug effects. Bibliographies of selected articles were also examined to include all relevant investigations. Economic data were identified using the terms costs and cost analysis and cost of illness.

STUDY SELECTION AND DATA EXTRACTION

Review articles, meta-analyses, and clinical trials describing epidemiology and classification of hospital-acquired ARF were identified. Results from prospective, controlled trials were given priority when available.

CONCLUSIONS

ARF occurs in up to 25% of critically ill patients, resulting in significant morbidity and high mortality. Characterization of ARF is difficult due to multiple etiologic factors and variable definitions. Limited cost data describe the extensive economic burden associated with the disorder, although further pharmacoeconomic research is needed. Epidemiology and classification of ARF allow prospective management of at-risk patients.

Renal sonography in the intensive care unit: when is it necessary?

OBJECTIVE

To evaluate the efficacy of renal sonography performed in intensive care units on patients with the diagnosis of acute or acute-on-chronic renal failure.

METHODS

We reviewed all renal sonograms performed in our institution during 1 year on critically ill patients for evaluation of renal failure. Renal failure was defined as a serum creatinine level greater than 1.5 mg/dL or an increase of greater than 20% from the baseline creatinine level. Exclusion criteria included patient age younger than 18 years and signs or symptoms of obstructive uropathy. Using the electronic medical record, we recorded patient age, sex, blood urea nitrogen level, serum creatinine level, blood urea nitrogen-creatinine ratio, and clinical indication for intensive care unit admission. Sonographic reports were reviewed for the presence or absence of hydronephrosis. The total cost of these examinations was estimated with the use of Medicare reimbursement rates for 2000.

RESULTS

One hundred five renal sonographic examinations were performed on 104 patients meeting all inclusion criteria. Only 1 study had positive results for hydronephrosis, which was graded as mild. Incidental findings not immediately affecting patient care and including ascites and simple renal cysts were identified in 91 patients. The estimated total cost of the examinations was $13,350.75.

CONCLUSIONS

In critically ill patients with acute renal failure and no physical findings suggesting obstructive uropathy, renal sonography to evaluate for hydronephrosis is probably not indicated. This holds true regardless of patient age, sex, medical or surgical disposition, and blood urea nitrogen-creatinine ratio.

Is peritoneal dialysis adequate for hypercatabolic acute renal failure in developing countries?

BACKGROUND

Peritoneal dialysis (PD) is a therapeutic option for acute renal failure (ARF) in developing countries, despite concerns about inadequacy. Shorter and more efficient tidal peritoneal dialysis (TPD) was compared with continuous equilibrating peritoneal dialysis (CEPD) therapy in ARF by using their adequacies as accepted standards and analyzing the solute reduction indices (SRI).

METHODS

A prospective, randomized crossover trial was performed in patients with mild to moderate hypercatabolic ARF who were assigned to CEPD and TPD therapy after an adequate washout period. Solute clearances (Kt/V, normalized creatinine clearances) were compared to NKF guidelines. Potassium and phosphate clearances, dextrose absorption, protein losses and costs were compared. Kt/V was compared to SRIdialysate, SRIKt/V.

RESULTS

Eighty-seven patients with ARF received 236 sessions of dialysis (118 in each treatment). TPD resulted in higher clearances of solutes than CEPD (creatinine and urea clearances in mL/min of 9.94 +/- 2.93, 6.74 +/- 1.63 and 19.85 +/- 1.95, 10.63+/- 2.62, respectively, P=0.001). TPD and CEPD normalized creatinine clearances (L/week/1.73 m2 BSA) and Kt/V values were 68.5 +/- 4.43, 58.85 +/- 2.57 and 2.43 +/- 0.87, 1.80 +/- 0.32, respectively. CEPD did not meet standards of adequacy. TPD resulted in greater potassium and phosphate clearances, less dextrose absorption and was less expensive. CEPD resulted in less protein loss. Kt/V corresponded to SRIdialysate 0.88 +/- 0.12 (P=0.076).

CONCLUSION

TPD produced higher solute clearances in less time with greater protein loss. CEPD just fell short to meet the dialysis adequacy standard. However, both TPD and CEPD are reasonable options for mild-moderate hypercatabolic ARF. Kt/V appropriately estimates solute removal in PD.

A randomized clinical trial of continuous versus intermittent dialysis for acute renal failure

BACKGROUND

Acute renal failure (ARF) requiring dialysis in critically ill patients is associated with an in-hospital mortality rate of 50 to 80%. The worldwide standard for renal replacement therapy is intermittent hemodialysis (IHD). Continuous hemodialysis and hemofiltration techniques have recently emerged as alternative modalities. These two therapies have not been directly compared.

METHODS

A multicenter, randomized, controlled trial was conducted comparing two dialysis modalities (IHD vs. continuous hemodiafiltration) for the treatment of ARF in the intensive care unit (ICU). One hundred sixty-six patients were randomized. Principal outcome measures were ICU and hospital mortality, length of stay, and recovery of renal function.

RESULTS

Using intention-to-treat analysis, the overall ICU and in-hospital mortalities were 50.6 and 56.6%, respectively. Continuous therapy was associated with an increase in ICU (59.5 vs. 41.5%, P < 0.02) and in-hospital (65.5 vs. 47.6%, P < 0.02) mortality relative to intermittent dialysis. Median ICU length of stay from the time of nephrology consultation was 16.5 days, and complete recovery of renal function was observed in 34.9% of patients, with no significant group differences. Despite randomization, there were significant differences between the groups in several covariates independently associated with mortality, including gender, hepatic failure, APACHE II and III scores, and the number of failed organ systems, in each instance biased in favor of the intermittent dialysis group. Using logistic regression to adjust for the imbalances in group assignment, the odds of death associated with continuous therapy was 1.3 (95% CI, 0.6 to 2.7, P = NS). A detailed investigation of the randomization process failed to explain the marked differences in patient assignment.

CONCLUSIONS

A randomized controlled trial of alternative dialysis modalities in ARF is feasible. Despite the potential advantages of continuous techniques, this study provides no evidence of a survival benefit of continuous hemodiafiltration compared with IHD. This study did not control for other major clinical decisions or other supportive management strategies that are widely variable (for example, nutrition support, hemodynamic support, timing of initiation, and dose of dialysis) and might materially influence outcomes in ARF. Standardization of several aspects of care or extremely large sample sizes will be required to answer optimally the questions originally posed by this investigation.

Mortality and costs of acute renal failure associated with amphotericin B therapy

To assess the mortality and resource utilization that results from acute renal failure associated with amphotericin B therapy, 707 adult admissions in which parenteral amphotericin B therapy was given were studied at a tertiary-care hospital. Main outcome measures were mortality, length of stay, and costs; we controlled for potential confounders, including age, sex, insurance status, baseline creatinine level, length of stay before beginning amphotericin B therapy, and severity of illness. Among 707 admissions, there were 212 episodes (30%) of acute renal failure. When renal failure developed, the mortality rate was much higher: 54% versus 16% (adjusted odds of death, 6.6). When acute renal failure occurred, the mean adjusted increase in length of stay was 8.2 days, and the adjusted total cost was $29,823. Although residual confounding exists despite adjustment, the increases in resource utilization that we found are large and the associated mortality is high when acute renal failure occurs following amphotericin B therapy.

Costs of care, long-term prognosis and quality of life in patients requiring renal replacement therapy during intensive care

OBJECTIVE

To assess (1) the long-term outcome of patients requiring renal replacement therapy (RRT) in terms of 6-month and 5-year mortality, (2) quality of life and (3) costs of the intensive care.

DESIGN

A retrospective observational cohort study.

SETTING

Twenty-three-bed multidisciplinary intensive care unit (ICU) in a tertiary care center.

PATIENTS AND PARTICIPANTS

Out of 3,447 intensive care patients admitted, 62 patients with no end-stage renal failure required RRT.

INTERVENTIONS

None.

MEASUREMENTS AND RESULTS

The incidence rate of acute renal failure (ARF) was 8/100,000 inhabitants/ year. The majority of patients (71%) had ARF in conjunction with multiple organ failure. The mortality in the ICU and in the hospital was 34 % and 45%, respectively. Mortality was 55% at 6 months and 65 % at 5 years. Renal function recovered in 82 % of the survivors during hospitalization. Loss of energy and limitations of physical mobility assessed by Nottingham Health Profile were the most frequently reported complaints at 6 months. Functional ability, as assessed by the Activities of Daily Living score was fairly good at 6 months. The cost per ARF 6-month survivor was $80,000.

CONCLUSIONS

There was only a minor increase in mortality after discharge from hospital among patients treated for ARF in intensive care. The costs related to ARF in intensive care are high, but the almost complete physical and functional recovery seen in ARF survivors should be noted in cost-effective analyses.