Economic consequences of renal dysfunction among cardiopulmonary bypass surgery patients: A hospital-based perspective

Background: Renal dysfunction is common after cardiopulmonary bypass procedures and is associated with higher mortality rates and longer lengths of stay. However, less is known about the actual cost of care for these patients. We sought to quantify the hospital costs attributed to renal dysfunction in cardiopulmonary bypass patients at a large academic referral center. Methods: All patients undergoing cardiopulmonary bypass procedures were identified through administrative databases for a 3-year study period. Renal failure was defined using laboratory values from the hospitalization. Total direct costs and costs by hospital department were determined using the hospital cost-accounting system. A multivariate linear model was developed to determine total direct hospital costs after cardiopulmonary bypass procedures after adjusting for relevant clinical and demographic variables. Results: Nine percent of the study population developed new-onset renal dysfunction, and 18% of patients overall undergoing cardiopulmonary bypass experienced renal dysfunction during the hospitalization. Direct costs were 42% higher for patients with renal dysfunction, an average of $5807 per case. Higher costs were noted in intensive care unit use and pharmacy, laboratory, and radiology services. Conclusions: Renal dysfunction increases the direct hospital costs of care, even after adjustment for age, sex, race, and comorbidities. Nationwide, we estimate that renal dysfunction may add up to $643 million in hospital costs for caring for cardiopulmonary bypass patients. Interventions designed to reduce the incidence and severity of renal dysfunction may significantly reduce hospital costs for these patients.