Emergency Room staff are perfectly capable of putting 200+ items on a physical board. Not writing tasks down because it's too time consuming doesn't result in a more manageable workload of tasks, it results in people trying to remember and forgetting.

The fundamental idea behind Kanban was WIP Constraint Management.

Unfortunately, so many people have been doing cargo-cult agile for so long that now the word "kanban" means 'task board with columns' to most people.

It should not be possible to put 200 items into a column on a Kanban board unless the team is actually shown to have the capacity to work on them without causing a bottleneck.