Earlier quoted context omitted.
Thats the typical way to handle a tension pneumo, which is slightly different but highly emergent. It's unlikely the case described was a tension pneumo because of the time period, but it very well could have developed that way, and regardless the treatment should be as useful - however one of the benefits of a needle decompression is that, because the lung has compressed so significantly, you don't have to be too co…
„emergent“ means the prevalence is increasing? Why?
Thats actually not the use here but that meaning is common. “Emerge” is simply Frenchified Latin for ausgehen.
In this case however it appears to be medical (perhaps ER) slang for “rapidly becoming an emergency”