A model of the direct and indirect effects of aprotinin administration on the overall costs of coronary revascularization surgery in a university teaching hospital cardiothoracic unit

Background: Cardiac patients sometimes bleed postoperatively and consequently require rethoracotomy, necessitating a longer stay in the intensive care unit (ICU) of the cardiothoracic unit (CTU). When ICU capacity is limited, rethoracotomy necessitates postponing treatment of the next patient. Aprotinin, a bovine lung-derived proteinase inhibitor, has been shown to reduce the frequency of rethoracotomies in cardiac patients. Objective: This study was undertaken to quantify the reduction of potentially avoidable cost to the CTU of postoperative bleeding, both directly and indirectly, by administering aprotinin before and during coronary artery bypass graft (CABG). Methods: A novel, validated operational research model was developed, featuring the principal CABG-related health care resource parameters believed to influence waiting lists and times. Factors and costs were derived from both local data from a CTU and relevant recent literature. Results: According to the model, aprotinin therapy reduced the waiting list by similar to3% by reducing the number of rethoracotomies. Using data from the literature, for an annual throughput of 431 patients who would receive aprotinin costing pound97,333 per year, the annual net savings to the CTU would be pound46,586, which comprised direct savings on blood products of 05,036 and indirect marginal savings of pound11,550 derived from 3.2% fewer rethoracotomies (each at a marginal cost of pound837). By reason, then, reinvesting savings in increasing CTU capacity would yield further waiting-list reductions and improve patient morbidity. These results had 2 major limitations. First, it was assumed that all operations would have the same duration and all surgeons would perform operations in the same manner. Second, nonurgent patients were assumed to have been treated in order of strict referral sequence, which may not be done in real-world practice. Conclusions: Aprotinin reduced costs in CABG directly by reducing the use of blood products and indirectly by reducing waiting lists, as well as by reducing morbidity and mortality associated with waiting time.