how Merrin came to the attention of Exception Handling
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Merrin doesn't actually know what backup would do that she isn't already doing! Can she get the latest estimates on whether adding higher doses of various vasopressors is even going to do anything - she doesn't want to do that, because once they're in the systemic circulation they will get into the patient's brain and hang out doing weird capillary-pressure interactions in a location where she doesn't have direct sensor data. But it would be nice to know what her options are. 

Does anyone have a theory yet for what's going on more specific than 'when you perturb this system, the system really doesn't like it', which is where Merrin's currently at. 

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Top general-hypothesis for what caused this, if not exactly what is currently going wrong at a level of granularity that suggests solutions: they did dilute the patient's blood very slightly? 100 ml of plasma, compared to a total estimated blood volume of 5100 ml (they have not literally measured his blood volume, it's an estimate based on the patient's weight and a few other factors) is a pretty small fraction, and it shouldn't have affected the vasopressor dosing or anything, but it might have affected local concentrations before it mixed, and it may have subtly shifted his blood chemistry - not electrolytes, those are stable, they're throwing the full suite of continuous blood sensor data at some modeling software now but it's a lot of data and they have a lot of hypotheses. There is ongoing debate and nothing is standing out yet in the diagnostic prediction markets, so it's not worth distracting Merrin with it. 

(An 'ongoing debate': a number of Very Serious People are quietyelling at each other. Merrin probably does not need to hear this. Merrin could go check the diagnostic prediction markets herself but is probably not going to do this in the middle of everything that's happening right now.) 

They can get some formal lab reads in case there's a sensor error causing them to miss something, unless Merrin thinks drawing 2 ml of blood is a bad idea. 

How's the patient doing?

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Merrin is not checking ANYTHING right now except for TWO NUMBERS. (...Wrongthought, she's tracking at least eight different things when you include all her machine settings and the ultrasound imagery.) However, Merrin sure isn't paying attention to the diagnostic prediction markets, or the treatment-planning ones actually, someone needs to interrupt her if they think of something for her to try. 

2 ml of blood shouldn't have any appreciable effect but Merrin is really confused and wants to note that on an intuition-level she feels like she has no idea how this patient works anymore. It's probably worth it, this is probably the most dramatic thing that's going to happen this hour? 

(Lab testing can be done with very small quantities of blood - even moreso when using top-of-the-line lab equipment, which they now have on site - but it still adds up, so they're not being frivolous about it.) 

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The patient's blood pressure is 31/23. His O2 sat is 59%. 

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Why are her numbers bad and wrong in OPPOSITE DIRECTIONS oh wait that makes sense, the oxygen already in his blood is being taken up more slowly.  

Check on whether she should try to cut blood flow to his brain further until the O2 is back in range or if 'trying to make your bad and wrong numbers cancel each other out' is the opposite of a good idea - actually now that she's said it out loud she's pretty sure she should not do that, but check anyway - 

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Rapidly-consulted experts on relevant body systems also think Merrin should not do that. They are more confident of this although not entirely in agreement. 

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Well great then. 

Merrin is...her intuition is saying that she should briefly drop the ventilator O2 concentration to 80%, drop the programmed heart rate further and max out the mechanical force for - thirty seconds is probably not going to kill more heart cells - and see if that gets the blood pressure back in range, in case it's the sort of self-reinforcing low blood pressure problem where it's low because blood isn't getting back to the heart because it was low ten seconds ago. She is not entirely sure why this might work it just feels like the sort of thing that might work, and it'll only take thirty seconds, and if something else starts to jump up in the prediction markets before the thirty seconds is up they can interrupt her.

If it does work it's going to mean briefly being further outside parameters but it feels like the best way to only be outside parameters briefly? Sorry Merrin is really distracted right now and doesn't want to take thirty seconds to try to make her reasoning legible can she just get a go or no-go?

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It seems obvious to at least a couple of people why this might be a good idea? If venous return to the heart is low then a higher heart rate means less time for it to fill and a rapid drop in cardiac output per beat, which at a certain point outweighs the increase in per-minute bloodflow from more beats per minute - and with real-time ultrasound imagery they can watch as Merrin drops it slowly over ten seconds, throw the recording at some analysis software, and come back with a suggested rate that maxes this. Also if she can get systemic bloodflow circulating, meaning more oxygen uptake, it should make oxygen saturation changes in response to setting changes faster and smoother, which will help Merrin avoid the repeated overcorrections when the measured response lags further. Also it's not going to do his non-brain tissues much harm, and might help, but Merrin really definitely can't let the carotid blood pressure go above 50/30. 

...Also update the diagnostic prediction markets are getting closer to settling. One rising hypotheses is 'something to do with nitric oxide concentrations: it causes potent vasodilation, the mechanism is simple and direct enough that it likely works even on cells at 20 C, and their process for getting the blood plasma from frozen to exactly the same temperature as the patient involved, for simplicity, reheating it to 37 C with the standard equipment and then controlled cooling from there, and it's possible this resulted in it containing more nitric oxide than is usual for infused plasma. Other contenders involve a reaction with the citric acid used as a preservative, and a few others to do with more obscure plasma proteins that have some enzyme functions. 

Good news if it's the first one: nitric oxide is very short acting, they might already be mostly past the window of effect and just still recovering from the resulting perturbations.

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Merrin will do all of those things! She's kind of scared, but externally this mostly comes out as looking absolutely furious at all of her equipment. 

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As recorded at five-second increments, at the patient's radial artery for reference (R), carotid artery (C) with [a] indicating manual adjustment with vasoconstriction, and O2 sat (direct carotid measurement). Measurement begun when mechanical force to cardiac pump increased, after a 15-second gradual drop from a set heart rate of 100 to one of 70. 

T0: R 27/23, C 31/24, O2 60% 

T+5s: R 30/22, C 34/23, O2 61% 

T+10s: R 32/21, C 36/25, O2 59% 

T+15s: R 35/23, C 39/24, O2 58%

T+20s: R 38/22, C 42/29, O2 57% 

T+25s: R 41/24, C 42/29 [a], O2 57% 

T+30s: R 46/25, C 45/25 [a], O2 56% 

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Recommendation that Merrin gradually increase rate to 80 over 15 seconds without adjusting the force setting and while keeping carotid systolic blood pressure between 40-45 if this is at all possible, maintain settings until O2 sat consistently under 50% with stable ventilator settings, then decrease force until no longer requiring constant vasodilator-constrictor manual adjustment to maintain carotid blood pressure below radial blood pressure. 

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...Sure, Merrin doesn't know why 80 but presumably their model spat out something more accurate that what she can figure out with just her eyes on the screen. (That was really fast, wow, it's actually super cool working with world-class experts as long as she's not in the process of embarrassing herself.) The rest she was planning to do anyway. Though if it takes more than two minutes she's really worried about further heart damage. 

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It does not really seem avoidable right now. It won't affect their immediate treatment plan; they're making preliminary plans to quickly arrange a heart transplant if, once they have the patient rewarmed and otherwise stabilized, his heart function fails to recover. (Obviously they aren't going to finalize anything until it comes to that.) The rewarming protocol taking shape likely involves (market at 80% that this is the best option for balancing risk and benefit) first transferring the patient onto a full heart-lung replacement machine, for tighter control of everything during rewarming. So they'll have time to react, if they get that far. 

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Merrin is NOT going to think about pacts made in Quiet Cities involving early cryo and organ procurement. She is going to PRETEND THIS IS A SIM wow she's kind of off-balance right now it doesn't usually bother her that much. 

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She's going to finish carrying out the instructions before worrying about silly things like whether Exception Handling is aware that she isn't actually certed to set up a full heart-lung replacement machine although, like, she can run one. Obviously they know what she is and isn't certed for, and her brain is being ridiculous by worrying that somehow for some reason they're going to decide she's the best person to do it anyway

 

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T+40: R 51/27, C 46/24 [a], O2 55% 

T+45: R 53/29, C 45/25 [a], O2 54% 

T+50: R 55/30, C 45/27 [a], O2 53% 

T+55: R 58/35, C 45/29 [a], O2 51% 

T+60: R 61/39, C 45/29 [a], O2 49% 

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Merrin lets out an audible exclamation of joy, says 'good job!' at the patient - or maybe the machines, it's sort of hard to tell - and then immediately rams the O2 concentration back up to 85% because, impairments in abstract reasoning or not, she is perfectly capable of extrapolating trends if they are that straightforward

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49%...

48%...

49%...

50%...

50%...

49%...

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"Does that count as stabilized yet can I stop." The patient's blood pressure did not actually keep going up much past a systolic of 60, but it's the highest she's seen it and her brain, used to the previous baseline, is insisting on finding it - the word she keeps landing on is creepy, which doesn't make a ton of sense. Also she is sort of worried that using the vasodilator-constrictor on almost its maximum setting for a minute continuously is not within its design specs. 

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She can start to back off very slowly on the force-settings, one increment at a time and wait at least fifteen seconds for it to settle, but yes. 

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(Okay Merrin did not actually need to be told that, she isn't stupid she is kind of stupid but that's, like, really basic practice for handling settings-changes on multiple interacting pieces of equipment). 

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It takes another five minutes to get everything back to sort-of-equilibrium, by which point the diagnostic prediction markets still going on what just happened have settled on 80% for 'nitric oxide interaction from the rapid plasma administration' - the remainder of the probability mass is split between half a dozen conflicting theories, citric acid is mostly out because that wouldn't have stopped causing problems so quickly. The current treatment recommendation, at least for right now, is 'already moot' - it was a short-acting substance causing a self-limiting problem, at least given that they got on top of it so promptly.

Less than 90 seconds outside parameters, even less than that for time spent off on both blood pressure and O2. Unfortunately, the post-incident analysis is concluding that both deviations were in the worse direction, and they're going to tweak some of the protocols to try to avoid any more incidents where a high O2 sat coincides with a low blood pressure 

 

...Probably unsurprisingly, there's a tiny spike in neural-cell-damage factors associated with reperfusion injury. It clears and drops back to below the detection threshold in less than five minutes, though, which means the damage isn't ongoing. It's not, by itself, indicative of a degree of damage that compromises their objective.

And it's useful information, in a way, if only to reinforce that they set the parameters right and really do need to stay within that narrow, narrow line.

They definitely can't afford for this to happen every time they swap out equipment, which means they should minimize doing that. 

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Merrin spends five seconds feeling like the most terrible person in the world and then tells herself to stop that, and then remembers that biting herself in front of Exception Handling is undignified. She bites the inside of her lip instead, so that it won't be conspicuous, and concentrates on her actual job. 

 

Fortunately for the patient, and also Merrin's sanity, the actual handover process and getting the settings calibrated right on the Complicated Liver Replacement Machine is, while incredibly obnoxious and fiddly and time-consuming, mostly not interacting with the patient's main vital signs. 

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...They are maybe having a temperature problem?

 

Which is new. Up until now, it hasn't actually taken a lot of effort to keep their patient between 20 C and 20.5 C. The air temperature in the room is 18 C, and while the bed is set with a simple thermostat-control hooked to the temperature sensor - standard hospital mattresses come with warming or cooling functions, obviously - it was barely doing anything. Apparently 'enough to maintain a two-degree temperature differential' was about the amount of metabolic waste heat their patient is producing. 

He's now at 19.1. 

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Merrin would like to register a complaint, this sim is unfair It doesn't seem that mysterious - given the timing it's clearly related to the Complicated Liver Replacement Machine, which does take blood out of the body and run it past cooler air. Probably someone who isn't her has noticed - 

"–I'm adding the heating-cooling controls to my console," she hears herself say. Great, as soon as she manages to hand off one of her machines, she acquires a new one. It's a lot simpler, though. And now that it's done, the more thorough coverage does seem to be helping, as dozens of different metabolic factors that had been ignored and slowly drifting entropy-ward are now being corrected. There are fewer fluctuations for her to handle. 

"It would be a really good time for some mild stimulants now," she subvocalizes to her assistant, and then - after reviewing her settings and sits back and grants herself, not a break exactly, but a precious fifteen minutes of being a purely-reactive attentional butterfly, existing only in the moment, the input of her sends, her hands moving almost by themselves.

It's not quite as good as a nap but it's surprisingly close to being as good as a nap, and for that fifteen minutes, not one weird thing happens to interrupt her. Bliss. 

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