This chapter discusses opportunities to improve emergency department (ED) flow through strategies to improve outflow. ED flow is based on the “input-throughput-output” model introduced by to emergency medicine in 20031 (Figure 38-1). In many EDs, the most significant barriers to flow exist in the outflow of patients from the ED. This leads to the concept that output obstruction (boarding patients) creates input obstruction (inability to bring waiting room patients into ED beds filled by boarders), or as stated by Mayer and Jensen, “It's difficult to open the front door of the ED (input) unless and until the back door of the ED (output) can be opened.”2
The third phase of flow—output—comprises patients who are admitted, transferred, and discharged.
Outflow obstruction does not obviate the need for ED leaders and staff to continue to address input and throughput over which they have moderate control. Input and throughput in the ED must be optimized in order to reap the benefits of improved output. This optimization requires leveraging strategic partnerships with other hospital leaders, that is, administration, medical staff, nursing leaders, and so on to continuously improve flow processes.
These improvement efforts are best viewed through the lens of a Lean leadership approach in which adding value and eliminating waste at each stage of every process are central tenets of the hospital's approach.2-4 This is complicated by the simple but often unrecognized fact that the ED discharges patients on a 24 × 7 × 365 basis, that is, patients are discharged throughout the course of every day. However, hospitals typically do not discharge patients or transfer them between inpatient units in the late evening or the early morning hours. Throughout this discussion, recognition of these 2 concepts will help to enhance discharge efforts:
- A Lean leadership approach should be employed to add value and eliminate waste.
- The ED discharges patients throughout the day and night, while the hospital's processes are most often geared to a more limited number of hours.
Outflow improvement requires hospital leadership, sustained commitment, and mobilization of significant resources throughout the organization. However, improvement in outflow does not by itself improve the patient experience. Other organizational inefficiencies can undermine credibility of ED leadership and impair further improvement efforts throughout the organization. Therefore, ED flow improvements require a combination of highly coordinated internal and external efforts to smoothly “flow” patients through the system. Without this consistent and organized focus, patients will experience long waits in the ED, either due to ED inefficiency or hospital flow constraints, which in turn often result in hospital crowding and ED boarding of inpatients. Prolonged delays result in poor clinical outcomes, dissatisfied patients, and financial losses.2-5
A wealth of data confirms that delays in outflow causing ED boarding lead to increased morbidity and ...