Pascal goes slightly cross-eyed. "...It'd make it refill less, or more slowly? Because the blood coming into the atria has to push against that pressure? And then that would drop his stroke volume even more." 

"Exactly! But that doesn't really explain why his BP bombs so hard when we lie him flat." 

Pascal scratches beside his nose, then looks sheepish and quickly Purells his hands. "Uh. Right. Normally laying someone flat helps with low BP from shock." 

"He is obese - gravity isn't helping his lungs any, when we lay him flat..." 

She looks down at the patient's taut, almost spherical belly, entirely disproportionate to his chubby but human-proportioned limbs. 

She touches it. Yep, he's more bloated than before. The skin is firm, like a pregnant woman. 

A gear finally clicks into place. "Oh fuck," Nellie says. With emphasis. "Jesus. I– fuck." 

Dr Agarwal is at the bedside ten seconds later. "What is it? Is it his sugars?" 

"No. But I have a really bad feeling. ...Do you guys have an on-call GI surgeon on nights. We need to page them and get a consult right fucking now. And get a bladder pressure measurement - if we're fast we can have it by the time they call back -" 

"He was ruled out for a bowel obstruction," Pascal says blankly. "He wasn't even constipated. What's a bladder pressure?" 

"Exactly what it sounds like. - Doctor, tell someone I need a pressure tubing setup primed and ready ASAP. It's the same as an art line or CVP except for the connecty bit. And I'll need a 60cc syringe, but NOT the feeding tube kind - find me the luer lock kind for IVs, I don't care if you have to go all the way to the ER for it." 

She turns back to Pascal. "So we were talking about intrathoracic pressures, yeah? Same concept applies to the abdomen. Usually not something we fuss with much, but. You learned about compartment syndrome in school?" 

He squints at her. "That's, like, when you get cellulitis or something and your arm swells up so much it pinches off the blood supply?" 

"Exactly. And this can happen in any 'compartment' of your body. It's worst in the brain, right, because that's a hella rigid compartment, there's no stretch. You're never gonna get compartment syndrome in your chest - if something starts filling it up, you die of the collapsed lung long before the pressure's high enough to cut off circulation. And the belly has a lot of stretch. But. Not infinitely much." 

Pascal is looking kind of nauseated. "Is he going to burst open?" 

"What? No!" Do NOT laugh at the kid, she has to remind herself. "Though it might be more survivable if it worked that way. But skin and fascia can hold up against more than a systolic blood pressure number - especially when it looks like that." She stabs a finger at the monitor. "So if I'm right - and I fucking hope I'm wrong - well, you know what happens when it's someone's brain, yeah." 

He looks pale. "You lose blood flow. Tissue dies." 

"Exactly. It's less critical on the scale of minutes, there's stretch in there, he's probably still getting some bloodflow. But it's a vicious cycle - if he does have tissue ischemia, it's going to swell more, make the situation worse. And if I'm right, it's already squashing his kidneys flat." 

"Ohhhhhh is that why the urine output..." 

Dr Agarwal comes running to the door, a pressure bag and tubing set dangling from his arm ready to go. 

Chantal is on his heels. "Nellie. What are you doing?" 

"Bladder pressure. It's a proxy for intra-abdominal pressure, so we know whether we have to send this guy to the OR stat to have his belly sliced open like a fish." 

Chantal looks uneasy. "It's not in our policies and procedures manual." 

"- Are you fucking kidding me. I'm giving it a fifty-fifty chance this guy's bowel is dying right now, we do not have time to argue about this. I've done this a dozen times at least in Austin." 

"It's risking your license, you know. To do a possibly-dangerous procedure that isn't cleared as a nursing task in our protocols. What if you rupture his bladder?" 

Nellie is mad enough to spit. She doesn't, though. Infection risk for the poor patient who's right there, belly forming a dome between them. 

"Jesus Mary and Joseph, I'm not going to rupture his bladder. Do you worry about rupturing your patient's radial artery every time you change your art line tubing?"

She looks around.

"...Fine. Fucking fine. I'm going to print off some instructions off UpToDate or whatever and I'm going to prepare everything and - Dr Agarwal, if I promise you that I'll walk you through every single step and that this is significantly easier than the art line you did earlier, are you comfortable taking a bladder pressure measurement so we can maybe save this guy's life?" 

There is a long, strained silence. 

"...Sure," the resident says in a small voice. "And I'll, er, page the surgeon." 

"Page the attending too. We all know how Dr Prissan feels about his beauty sleep, but he's off call in -" she looks at the clock, "five hours, and he's gotta be here if we're sending his patient to emergent surgery in the middle of the night." 

Chantal stands by the door, tapping her foot and looking anxious.

She shouldn't but she's MAD and she can't help it. "If you have to glare at me for my hubris," Nellie says coolly, "you could at least make yourself useful and get a blood sugar, we're past due." 

Things happen around her from then, with only occasionally prompting needed. The GI surgeon calls back, speaks to the resident, looks at the patient's chart for about fifteen seconds, and agrees to drive over and have a look in person. Even Dr Prissan reluctantly agrees to come back in. 

A bladder pressure is obtained and read off, Dr Agarwal standing with his laptop on a stolen bedside table just outside the room, reading the guidelines on normal versus elevated values. The number is coming up at 23. 

Dr Agarwal squints at the screen. "That's...a grade III intra-abdominal hypertension? How bad is it?" His eyes go to Nellie.