A couple of cars pass without actually stopping, before someone does screech to a stop a few yards down the sidewalk, leaving their car running while they dash into the corner liquor store yelling for help. 

...This is honestly not even the first time that the proprietor of this particular corner liquor store has been frantically summoned because someone was bleeding on the sidewalk outside his establishment. This is the first time it's happened during daylight hours, though, or to someone in cosplay (???) carrying a literal sword (???????). 

He takes one look at the pool of blood, snaps at the random bystander to call an ambulance, and goes back in for the first aid kit.

Where's the young woman bleeding from? Is she conscious? Does she seem to be breathing? 

She's bleeding from kind of a lot of places! They don't look like gunshot wounds or stab wounds, more like something ripped chunks out of her. She's not conscious but is breathing, and her pulse is weak but steady. 

This is definitely beyond what his first aid kit can handle! Also really confusing! It takes three seconds to confirm that the person who stopped did not at all see what happened, and then he'll try to find where she's bleeding the most and put pressure there, he doesn't have enough hands to get all the places. 

It's going to be at least five minutes before an ambulance gets here. He really hopes she doesn't die on the sidewalk in front of him before that. 

She doesn't die on the sidewalk! She actually looks surprisingly okay for how much of her blood is in places other than her body. Which is still not very okay. 

That’s a relief! He’s never seen anyone die before and that would be so upsetting.

The ambulance is there within 6 minutes, lights and sirens on, and pulls over at the corner. Two paramedics spill out with the gurney and equipment bag, and - okay, wild animal attack or something?? (The call they got was somewhat confused and mostly just covered “someone unconscious and bleeding.”)

The bleeding is pretty bad! Doing something about that is definitely a priority! They’ll confirm the patient is breathing and had a pulse, and then one of them will try to get pressure dressings on all the wounds while the other puts an oxygen mask on the woman and checks her vital signs. 

Heart rate of 160, blood pressure 70/40. She doesn't react to anything they do, but does keep a death grip (metaphorical, so far) on her sword and shield. When they manage to pry a finger loose to check her O2 sat, it's 97%.

…Kinda weird but it doesn’t seem like the most salient part of the situation, except that they do actually need to get the sword at least out of her hand so it’s not, like, flopping around being hazardously sharp as well as gross and slimy (????) when they get her onto the stretcher and into the back of the ambulance. They’ll delay actually departing to spend a minute or two attempting an IV to start fluids; it’s a lot harder in the back of a moving ambulance even when the patient isn’t trying to bleed to death and running a really low blood pressure.

The sword can get wrapped in an extra blanket. It looks like it maybe ought to go in a biohazard bag but they don’t actually have one big enough.

It'd just poke a hole in the biohazard bag anyway. Once it's out of the way, she's pretty easy to stick an IV in; her armor only covers her torso and her veins are well-behaved all things considered.

Oh good! They'll start a liter of saline running into her and book it to the hospital. 

How under control is the bleeding after their hasty bandaging work? 

Well, it's not coming out in spurts anymore. It's still leaking around the dressings from some of the more irregularly shaped wounds, including the nasty gut wound, and saturating the others. It doesn't appear to be clotting at all.

Well that's not great! There's a limited amount more they can do from the back of an ambulance, except radio ahead that the patient incoming is likely to need multiple blood transfusions, urgently. 

How are her vital signs doing? 

Her BP is down to 55/30, and her heart has sped up to 175, but it's still beating steadily and somehow keeping her O2 sat at 97.

The ER knows to expect her, and a team of nurses is already swarming out to meet the ambulance and help rush the patient to the trauma bay.

“What’s our IV access - we need a second line -”

     “Let’s get a stat CBC* sent off -”

“She’s still bleeding - someone hold pressure on that one -”

     “I’ve got two units of O-negative here, but can we do a type and cross ASAP, please…”

Within a couple of minutes  they have another two large-bore IVs, running a second liter of saline, the initial offering of blood, and a norepinephrine drip to try to get her blood pressure up to something more reasonable while they work on replenishing her blood volume. Two nurses are occupied trying to manually hold pressure on several of the wound sites, since bandaging them is apparently not sufficient. 

Her oxygenation is somehow still fine, but they definitely need to secure her airway; one of the residents is already unpacking an intubation tray. Is she still completely unresponsive? 

*Complete blood count. 

Yup. She might have twitched a bit back in the ambulance when they took her sword and put the first IV in, but she doesn't react to the new ones at all. She does cough and gag when they go to stick the intubation tube in her throat, not in a way that suggests she's having any subjective experiences about it but enough to be inconvenient.

Yep, that's inconvenient! She can get some sedation for it, which hopefully won't completely tank her blood pressure, they don't have that much room to go up on pressors. 

...The ER attending is going to order another two units of O-negative blood without actually waiting for the type and cross, judging by the amount of blood saturating the second layer of pressure dressings (added on top without disturbing the existing ones, to avoid disrupting any newly-forming clots), they can't afford to wait.

Inconveniently, the OR isn't going to be ready for her for another twenty minutes; ideally they would use that time working on getting her more stabilized for it. Is there any indication that with enough physical pressure on the bleeding sources, they're getting the ongoing blood loss at all under control? 

Well, between the pressure physically holding the blood in like a dike with a lot of fingers in it and the lack of blood pressure pushing the other way, there's definitely less coming out per unit time? The transfusion going in is mostly keeping up with what's dribbling all over the gurney.

Seems likely there are some severed arteries in there.

This…might be the best they can get here without messing around with the deep wounds more than is a good idea in a unsterile environment. They can keep up pressure on the spurting wounds, keep fluids and blood going into her hopefully fast enough to not to lose more ground, and try to prop up her blood pressure to at least 80 systolic in the meantime with heroic doses of vasopresssors. And - since they’re waiting anyway - maybe the doctor will have a go at cleaning and stapling any shallower injuries, so there’s less to deal with later.

The shallow injuries also want to dribble everywhere! Even the ones that can't possibly have hit an artery start leaking like her blood is so much water as soon as the pressure comes off. (She is at least responding fairly normally to the pressors.)

…That’s pretty concerning. 

He’d like them to send a clotting panel ASAP. In the meantime, absent a specific diagnosis of what's wrong, they can prioritize giving her plasma rather than saline, it's at least got a reasonable balance of clotting factors in it. The blood counts should be back soon and will alert them if there's a problem with her platelet count. The shallower cuts that he's already committed to cleaning can get hemostatic gauze slapped on them, and the rest can get left alone under dressings.

It's a really bad idea to take her to the OR like this, sooooo they had better manage to keep her stable or at least alive long enough to figure out what's going on. She looks generally healthy and fit, and it would be a pretty baffling decision for a hemophiliac to equip their cosplay outfit or whatever the heck it is with an actual sword. 

(The nurse is going to put in lab orders for Basically Everything, actually, might as well do all the standard ICU admit orders now.)

It takes twenty-six minutes from her arrival in the trauma bay for the stat complete blood counts to come back, during which time they manage to get three units of O-negative packed red blood cells and another three bags of plasma into her. 

Her blood count, from before a lot of her blood got replaced with other things: 

Hemoglobin: 8 g/dL (too low)

WBC: 12,000 mm^3 (a touch high)

Platelets: 100,000 mm^3 (too low again)

Everything else is reasonable. Also she's (a weird obscure ethnic variant of?) A positive. (Her ethnicity isn't obvious either; she might be white or Middle Eastern or Hispanic.)

...Okay, lowish platelets but not nearly low enough to explain what looks like a complete and utter inability to clot. It’s probably not a bad idea to transfuse a bag of platelets anyway - she’s lost even more blood since the sample was drawn, and had it replaced with packed red blood cells and plasma, neither of which actually include the platelet component. 

He’ll put in an order for that, and then spend a minute or so thinking. She’s still losing blood a lot faster than he’s happy with; it’s going to be pretty hard to keep her stable long enough to diagnose the problem and pick a targeted treatment. The longer they wait, the worse shape she’ll be in when she does eventually make it to the OR.

...They can give vitamin K, which will only help in the scenario where her problem is a vitamin K deficiency, but shouldn't hurt if it's an unrelated problem. And they might as well give tranexamic acid - it's an anti-fibrinolytic and should generically improve clotting ability for a range of underlying causes. Probably not by enough, when they're starting it this late, but it might at least buy them some wiggle room.  

Is her blood pressure holding up? Does anything else seem to be getting worse? 

Her blood pressure is not holding up, actually! Possibly because her heart rate has gone down a bunch.

That's not great! ...They're pretty much maxed on the norepinephrine now. They can start a dopamine drip as well as an interim measure, that will do more to increase heart rate, but it's almost certainly not going to address what the underlying problem is. It looks like the source of the problem is that her heart is no longer compensating as well for her massively compromised volume status, which - could just be exactly what you expect, even a healthy young person can't run a heart rate near their maximum indefinitely without their body starting to run out of steam - but it might be something they can actually address. 

"Hmm. Let's get a blood gas on the iStat. If her hemoglobin is low enough, she could be hypoxic even with a technically normal O2 saturation..." 

The blood gas comes back with an acceptable PaO2, but a seriously low pH and bicarbonate. Also, despite definitely not being hypoxic, she's picked up a blue tinge to her lips.

That’s not ideal! Either her lactate is really high - even higher than you’d expect given the degree of shock - or something else is metabolically wrong. Her CO2 is normal, leaving her pH totally uncompensated, probably because she’s too deeply unconscious to breathe above the ventilator rate. They can increase that, and give her a couple of amps of sodium bicarbonate.

….Someone thinks to check her temperature. It was normal when she arrived and it hasn’t been much more than half an hour, but they did give her quite a lot of room-temperature IV fluids.