A crowded emergency department looks like a problem with emergency care.
Patients occupy treatment bays for hours. New arrivals have nowhere to go. Staff struggle to keep patients moving through the service.
The obvious response is to look at the emergency department itself. Does it have enough space? Enough treatment bays? Enough staff?
But what if part of the problem lies elsewhere?
In a 2025 editorial in Emergencias, Juan Jorge González Armengol argues that emergency department crowding can reflect how the wider healthcare system functions. One particularly important cause is the delay in transferring patients who have already been assessed and need hospital admission. When no inpatient bed is available, these patients remain in the emergency department, occupying space that other patients may need.
The emergency department becomes the place where a wider hospital problem becomes visible.
This raises a question that matters for hospital design: if the causes extend beyond the emergency department, can we understand its capacity by looking only at the department itself?
A treatment bay is not simply a space. It is part of a patient journey. How long that bay remains occupied depends not only on the time needed for assessment and treatment, but also on what happens before the patient can leave it.
If the next step is delayed, the bay remains occupied. As more patients accumulate, the department can lose its ability to receive new arrivals—even if demand has not increased and the number of bays has not changed.
Adding more space may help. But it does not necessarily resolve the process that is preventing patients from moving forward.
This is why emergency department capacity should be understood through the entire patient journey, including the points where patients leave the department. The question is not just how many patients a department can accommodate, but how effectively the system can move them through the care they need.
Sometimes, the place where a problem appears is not the place where it begins.
For hospital planners and engineers, recognising that difference is an essential first step towards designing more effective emergency care.
Reference
González Armengol JJ. La atención en urgencias y los pacientes en espera de cama de hospitalización como síntomas visibles del funcionamiento global de los sistemas sanitarios. Emergencias. 2025;37:323–325
About this research
This article draws on a four-month research project conducted as part of my Master’s Final Project in Hospital Engineering and Architecture at the University of Cádiz, Spain, which received a grade of 9.5/10.
The research examines demographic trends, hospital designs and functional plans, emergency care processes, and the perspectives of emergency department professionals gathered through surveys. It culminates in the development of a digital twin simulation model designed to explore multiple scenarios and analyse how different factors affect emergency department operational capacity.