Patient Flow in Congested Intensive Care Unit /Step-down Unit system: Premature Step-down or not?

A Step-Down Unit (SDU) provides an intermediate Level of Care for patients from an Intensive Care Unit (ICU) as their condition becomes less acute. SDU congestion, as well as upstream patient arrivals, forces ICU administrators to incur costs, either in the form of overstays or premature step-downs. Based on a proxy for patient acuity level called the `Nine Equivalents of Nursing Manpower Score (NEMS), patients were classified into two groups: high-acuity and low-acuity. Two patient flow policies were developed that select actions to optimize the system s net health service benefit: one allowing for premature step-down actions, and the other allowing for patient rejection actions when the system is congested. The results show that the policy with patient rejection has a net health service benefit that significantly exceeds that of the policy with the premature step-down option. Based on these results, it can be concluded that premature step-down contributes to congestion downstream. Counter-intuitively, premature step-down should therefore be discouraged and patient rejection actions should be further explored as viable options for congested ICUs.