Patient mix optimization in tactical cardiothoracic surgery planning: a case study

Cardiothoracic surgery planning involves different resources such as operating theatre (OT) time, medium care beds, intensive care beds and nursing staff. Within cardiothoracic surgery different categories of patients can be distinguished with respect to their requirements of resources. The mix of patients is, therefore, an important aspect of decision making for the hospital to manage the use of these resources. A master OT schedule is used at the tactical level of planning for deriving the weekly OT plan. It defines for each day of a week the number of OT hours available and the number of patients operated from each patient category. We develop a model for this tactical level planning problem, the core of which is a mixed integer linear program. The model is used to evaluate scenarios for surgery planning at tactical as well as strategic levels, demonstrating the potential of integer programming for providing recommendations for change.