Incorporating Patient Deterioration When Simulating Utilization of a Cardiovascular Intensive Care Unit

Patients undergoing many forms of cardiovascular surgery typically enter the cardiac intensive care unit (CICU) after surgery, transfer to a step down (SDn) unit, and then are ultimately either discharged or bounce back to the CICU because of deterioration. Randomness and unpredictability exist in these processes, especially the bounce back process. Underestimation of bounce back rates will result in a lack of bed capacity for patients and patient deferrals. Adding beds, however, will lead to an increase in cost. Therefore, trade-offs must be carefully considered between decreasing patients denied versus potential system costs when bounce back is introduced to the system. We present a discrete-event simulation model to assess how bounce back will impact assessment of bed capacity in the CICU and SDn and other major metrics of the system. We present analyses utilizing data from our collaborators at the Samuel and Jean Frankel Cardiovascular Center at Michigan Medicine.