Cost of acute renal replacement therapy in the intensive care unit: results from The Beginning and Ending Supportive Therapy for the Kidney (BEST Kidney) study

Abstract

Introduction: Severe acute kidney injury (AKI) can be treated with either continuous renal replacement therapy (CRRT) or intermittent renal replacement therapy (IRRT). Limited evidence from existing studies does not support an outcome advantage of one modality versus the other, and most centers around the word use both modalities according to patient needs. However, cost estimates involve multiple factors that may not be generalizable to other sites, and, to date, only single-center cost studies have been performed. The aim of this study was to estimate the cost difference between CRRT and IRRT in the intensive care unit (ICU).

Methods: We performed a post hoc analysis of a prospective observational study among 53 centers from 23 countries, from September 2000 to December 2001. We estimated costs based on staffing, as well as dialysate and replacement fluid, anticoagulation and extracorporeal circuit.

Results: We found that the theoretic range of costs were from $3,629.80/day more with CRRT to $378.60/day more with IRRT. The median difference in cost between CRRT and IRRT was $289.60 (IQR 830.8-116.8) per day (greater with CRRT). Costs also varied greatly by region. Reducing replacement fluid volumes in CRRT to <or= 25 ml/min (approximately 25 ml/kg/hr) would result in $67.20/day (23.2%) mean savings.

Conclusions: Cost considerations with RRT are important and vary substantially among centers. We identified the relative impact of four cost domains (nurse staffing, fluid, anticoagulation, and extracorporeal circuit) on overall cost differences, and hospitals can look to these areas to reduce costs associated with RRT.

Figure 1

Median difference and range of nursing costs by region. The error bars represent the absolute range between the maximum nursing cost of CRRT and the minimum nursing cost of IRRT on the right, and between the maximum nursing cost of IRRT and minimum nursing cost of CRRT on the left. The box represents the 1^st and 3^rd quartiles of the nursing-cost range. The thick solid line represents the median difference in nursing costs for CRRT and IRRT across all centers in each region in which data were available.

Figure 2

Median difference and range of dialysate and replacement-fluid costs by region. The error bars represent the absolute range between the maximum fluid cost of CRRT and the minimum fluid cost of IRRT, and between the maximum fluid cost of IRRT and minimum fluid cost of CRRT. The box represents the 1^st and 3^rd quartiles of the fluid-cost range. The thick solid line represents the median difference in fluid costs for CRRT and IRRT across all centers in each region in which data were available.

Figure 3

Median difference and range of anticoagulant costs by region. The error bars represent the absolute range between the maximum anticoagulant cost of CRRT and the minimum anticoagulant cost of IRRT, and between the maximum anticoagulant cost of IRRT and minimum anticoagulant cost of CRRT. The box represents the 1^st and 3^rd quartiles of the anticoagulant-cost range. The thick solid line represents the median difference in anticoagulant costs for CRRT and IRRT across all centers in each region in which data were available.

Figure 4

Median difference and range of extracorporeal circuit costs by region. The error bars represent the absolute range between the maximum extracorporeal circuit cost of CRRT and the minimum extracorporeal circuit cost of IRRT, and between the maximum extracorporeal circuit cost of IRRT and minimum extracorporeal circuit cost of CRRT. The box represents the 1^st and 3^rd quartiles of the extracorporeal circuit-cost range. The thick solid line represents the median difference in extracorporeal circuit costs for CRRT and IRRT across all centers in each region in which data were available.

Figure 5

Median difference and range of total cost by cost domain. The error bars represent the range between the maximum cost of each domain for CRRT and the minimum cost for IRRT and the maximum cost of each domain for IRRT and minimum cost for CRRT. The box represents the 1^st and 3^rd quartiles of the total cost range. The thick solid line represents the range difference between the median cost differences for CRRT and IRRT. The thick white line represents the median difference of fluid costs when we limit replacement-fluid rate to 25 ml/min.