To set up this Tinker-to-Evers-to-Chance triple play, WRSA linked to an American Partisan article posted by NC Scout, the gist of which was a link to an SF article on prolonged casualty care, and the "guerrilla hospital".
Presumably in the context of people thinking of some sort of grid-down problem, long- or short-term, anywhere in a spectrum from between post-Katrina ugliness all the way to full flaming Zombpocalypse, including in the intermediate range, moderate to severe civil unrest/guerrilla warfare in CONUS.
Probably 95% or more of casual readers who follow that will be thinking, "Yessirree, we're gonna need us one of them there go-rilla hospitals!"
Sorry, kids, you won't be having any of that.
The article in the OP was concerned with actual SF medics, with access to modern drugs, satellite communications, air drops, a logistical tail that reaches any point on the globe, given enough time, and ultimately the entire US military's medical behemoth for back-up, sooner or later.
You. Won't. Have. Any. Of. That.
You might could handle a clinic, or convalescent hospital, by which I mean a place to get well or die. That you could manage to pull off, from 1 bed and up, and I've suggested a bare bones framework on how you might think about doing that. But it will not be anything like what you know as a hospital, from any time since 1960 or so, and it won't be even as modest as the "guerrilla hospital" Col. Farr is talking about in the linked article.
Here's what you won't need, and what you won't have, hence what you won't be doing to save anyone's life.
You won't have anesthesia. You won't have analgesia, except moonshine or weed, in all likelihood. So without those two things, you won't have surgery of any type other than "Civil War v1.0"-type. Complete with bone saws, sepsis, and spurting arteries after amputations.
You won't have cardiac code drugs. Nor supplemental oxygen in metric f**ktons. (A re-purposed O2 concentrator running up to 6 lpm? Maybe. Putting people on ventilators at 15-100 lpm? NFW. Not happening.) So you don't need protected airways, defibrillators, ventilators (large nor portable version), nor any other such nonsense. Forget CPR. Waste of time and energy.
Thus any cessation of heartbeat or respiration will go by what medical professionals quaintly refer to as "Death".
You're unlikely to have the ability to transfuse blood products, let alone type and screen donors and recipients.
You might cobble together enough antibiotic doses to save a couple/three folks from serious wounds, if they aren't liable to bleed to death first. But when those are gone, your only antibiotics will be mold on bread, which isn't the same thing as penicillin.
So what are you going to need? In the immortal words of one famous Special Forces operator:
Calvin Coolidge Jr., son of the sitting president, played tennis with his older brother John on the White House tennis court without socks in 1924, got a blister, which became septic, and he died within a week. No antibiotics. Just like you won't have.
Should you gather medical supplies, and get CPR and medical training?
Hell YES! It ain't the Zombpocalypse yet, and that stuff and the know-how is always handy to have. And you should absolutely do as much as you possibly can, or can prepare for.
But get a better grip on what you will and won't be able to do.
When Ebola got here the first time, I lost track of how many people I tried to tell "You aren't going to "treat" this. You're either going to isolate, or die from it if you don't."
"But I can't abandon my family members! I'd HAFTA try!"
Said every one of 50,000 dead family members in Liberia, Guinea, and Sierra Leone that same year who tried that. Suture self.
Now, with a year of weak-ass COVID under your belts, many of you who contracted it infected by other family members, you can see what a year on your own is like, to a very small degree, and that's with a virus with, at worst, a 3% fatality rate. (Like we told you.)
Look up casualties in WWI and/or the Civil War, for either side, and get back to me.
That's the level of medical care you'd be looking at providing/accessing in any serious "problem", over the long run.
So expect similar death rates when you revert to medical expertise last seen from 1860-1940.
Some few of you maybe might have a doctor, P.A., etc. handy.
D'ya know what you call a cardiologist or internal medicine specialist without a hospital around him, 98% of the time?
Because that's what you've got with no labs, no pharmacies, no imaging, and minimal facilities.
Don't believe me; ask them yourself, and see how fast they laugh at the idea of modern health care without anything that differentiates it from 19th century medicine, other than a bit more insight into certain things.
Then go back and read ,Rawles' HTSTEOTWAWKI, and find the part where he mentions the great "Die Off".
Now you can imagine why it's so.
Absolutely prepare as much as you can for anything and everything that concerns you.
But FFS, have some realistic expectations of what you can and cannot do with your two hands, and whatever bag of goodies you cobble together for bad times. Reality is going to be harsh enough in any bad situation without the double sting of shock because you thought it was going to be a picnic.