What do we know about emergency room triage?

When the emergency room gets a huge influx of cases in a disaster it's time for triage, the separation of the those most likely to need and benefit from immediate emergency care from those that can wait or can't be helped. In a mass casualty disaster the assumption is that triage should start outside the doors of the ER, sending only the sickest there. Makes sense. But is it true? A computer simulation done by Cornell Medical School suggests it might not be:

. . . researchers at NewYork-Presbyterian Hospital/Weill Cornell Medical Center have created a computer simulation model of trauma system response to mass casualty incidents involving dozens or hundreds of injured victims. The study shows that the best response depends more on the capability of regional hospitals to treat critically injured victims than on the ability to accurately identify those victims in the field.

"There's been the notion gleaned from prior studies that 'overtriage'--letting some people into emergency care who might not actually need it--usually ends up costing lives, with deaths rising as overtriage rates increase. But our new model demonstrates that overtriage alone is unlikely to be the culprit," says lead researcher Dr. Nathaniel Hupert, assistant professor of public health and medicine at Weill Cornell Medical College and assistant attending physician at NewYork-Presbyterian Hospital/Weill Cornell Medical Center. (Sciencedaily)

The problem is that the out-of-ER triage system has to be right. Making split second decisions is not a recipe for accuracy. Once this is taken into account, other factors, such as overall capacity and processing time are more important. If you let more in than you should, you also decrease the errors of keeping some out that you should have seen. But it depends on how much capacity you have:

"In some cases--for example, when the risk of death over the short term is high but you have a really large capacity to care for the injured--we can now show how overtriage may actually be a good thing, because you get more people into emergency care than you would otherwise," Dr. Hupert says. "On the other hand, if you have a more limited capacity, overtriage can be much less valuable, and perhaps harmful."

So if you have limited reserve capacity you probably need to triage outside the ER. "Overtriage" won't matter if you can't handle what's coming in. But if you can, then overtriage might hurt. It will depend on local conditions. Right now, though, these conditions aren't taken into account. Plans are based on limiting overtriage.

The simulation was designed for a mass casualty trauma event. It would seem, though, that the same lessons would apply to a pandemic or disease outbreak. Intake rate would be less and processing time could be speeded up, once knowing this is a critical variable. We need more efforts like this specifically aimed at pandemic scenarios.