Eeeeeee she knew he could do it! 

Kalorm's kidneys are working a little better - not incredibly well, and there probably is actual organ damage there, but a healthy 25-year-old has a lot of redundancy. Merrin is not having to work nearly as hard on maintaining basic electrolyte levels. 

His circulatory system continues to be deeply confused about whatever bizarre thing(s) just happened to it! Various hemodynamics control systems are coming back online in a confusing and unpredictable order, but - overall, the trend is toward more physiological regulation happening on its own. Merrin will have to change her approach, multiple times, but the overall cognitive load for her should still be decreasing over time. 

Also! At 29 C and a systolic blood pressure of 95 mmHG and almost-a-normal-O2-sat, his hands are no longer mottled! Capillary refill is still delayed, but still. 

Merrin is JOY and DELIGHT

- and also, oh nuclear contaminated sewage sites, she wants to be done with this. But Kalorm is VERY GOOD and if he can tough this out then so can she! 

...With effort, though. 

It is still not mostly that she feels subjectively tired, and even less that she's anywhere close to collapsing in exhaustion. Just. She is getting to the point where she can start to notice (in the moments when she has any capacity to notice anything) her motivation-system engagement starting to lose its hold.

A little. Not very much, yet. Merrin has played this out before, and she is very sure she can make it through the next 90 minutes. Just. There are some emotional levers that she has been mashing very hard, repeatedly, and their responsiveness is now on a slow downslide.

(She's been in this position in sims. She knows that she can and will keep working even after the point where her intrinsic motivation and reward system are out of juice - even at the point when everything feels fake and pointless and literally the best reason she can give herself for it is "well, I was already doing it and I'm not done yet." She's stupider, and worse at things, but she doesn't just stop.) 

...That is not what's going to happen here, though, because in fact Merrin is still mostly doing fine, and she only has 90 minutes left to go. 

11 hours in, one hour to go. Core temperature at 30 C. At this point in the protocol, they're aiming for a close-to-normal oxygen saturation and a low-end-of-normal blood pressure. Kalorm's heart is basically behaving itself (at least while the pacemaker is going.)

Merrin is still having to deal with random blood pressure fluctuations, as Kalorm's various circulatory-regulation systems come back online and are extremely confused about whatever just happened to them.

His feet are still slightly mottled, with dubious capillary refill, but his hands...look almost okay? Still pale, still a little bit colder than hands should really be when the surrounding room is at a pleasant indoor temperature, but his nailbeds are pink and the capillary refill time is barely distinguishable from normal. 

Okay forget the part about starting to feel motivationally disengaged! Her patient has SIGNS OF GOOD CIRCULATION his hands are PINK Merrin is filled with joy and pride this is one of the PEAK HEDONIC EXPERIENCES OF HER LIFE!!!!*

Merrin does a HAPPY DANCE and doesn't even feel self-conscious about it, because she is fifteen and a half hours into a shift and she is too socially fried for embarrassment to even still be working, her brain has room only for patient observations and sensor data and machine settings now, and self-consciousness went offline around the same time that her impulse control around not swearing out loud at her machines did. Everyone else can DEAL with the noise pollution. Also, she is now solidly on a euphoric rather than irritable stimulant high. 

She sings to herself under her breath as she fiddles with his hemodynamics, and then politely informs Kalorm that his blood pressure does not actually need to be 140/90, that is unnecessary, she appreciates that he's trying but he can try slightly less hard than that? 

*Probably not actually, but Merrin has lower-than-average levels of what one might call emotional object-permanency; unlike how many dath ilanis would in her place, she's not comparing this to past happy moments. And it might genuinely be among her top happiest moments in a medtech context? It's by far the highest-stakes patient case she's handled so far, it's also by far the longest, and thanks to the entire way that Merrin works as a person, she's coupled her reward system very tightly to the variations in the patient's condition. If the outcome ends up being a bad one, the cost is that Merrin will be absolutely devastated - well, everyone on the case will be, but Merrin in a particularly visceral way - but the upside is that little moments like this one bring her an intensity of joy that is, for most dath ilanis, pretty hard to achieve period. 

Merrin is a strange alien, and Personnel (who is back on-shift after rotating with one of the other Exception Handling Personnel, who also just goes by Personnel rather than her name, and taking a six hour nap, he cannot actually work that long a shift but he recovers unusually quickly) is kind of worried about how hard it will hit her if Kalorm's outcome isn't good. But right now this is mostly very adorable. 

31 C. Liiiiiiterally just another half-hour to go! 

...Their problem is now that Kalorm's physiological systems are coming too online, blinking in the sudden metaphorical daylight of an only-moderate-hypothermia body temperature, noticing the sheer number of things that are not really how they are supposed to be, and FREAKING OUT. 

They actually deliberately raised his sodium back to 160 a few hours ago; it cuts the risk of cerebral edema, makes it less likely that slightly-damaged cells struggling to maintain their ion gradients will end up taking on enough water to burst and die fully. (Also, a 20 mmol/L drop as fast as the one they did is a lot, even if his sodium had only been at 180 very briefly with no time for systems to recalibrate themselves to that as a normal state.) They're also deliberately keeping his magnesium somewhat above normal limits, because it's somewhat helpful for keeping cells, including heart muscle cells and neurons, less irritable - it's not that high, too high will cause neurological and heart problems, but at this level the riskiest physiological side effect is low blood pressure and it sure does not seem to be doing that. It's still high enough that if he were awake right now he would be feeling terrible about it. (Early symptoms of high magnesium: headache, flushing, nausea and vomiting.) 

Kalorm's kidneys do not think this is the correct state of affairs! They are correctly noticing that he's not dehydrated and they don't need to conserve water as hard as possible, and so they are trying very hard to drag Kalorm's electrolyte levels back to what they think is correct. 

"You're trying too hard again," Merrin informs Kalorm in a conversational tone, and then maxes out several settings on the hemodialysis and glares at filter pressure levels. On the bright side, his blood viscosity is a lot closer to normal at this temperature; on the downside, this filter has been in use for like fifteen hours, a number of those hours were at a temperature kind of outside its technical specs, and there's enough crud accumulating to make the semi-permeable membrane of the filter somewhat less permeable. 

Hopefully they won't need it for that much longer, but if they can't get his over-eager sodium regulation system under control with drugs, they may need to make it last another 12-24 hours while they slowly bring his sodium levels back to normal. 

"Maybe you can at least help me out by taking more water off so I don't have to?" she says, squinting at the urine drainage bag. "If you can put out 10 ccs in the next 5 minutes then I can afford to up the dilutant and I won't have to take the extra off at end-circuit. That would be super helpful and if you do it I'll increment your cookies-owed tally by one." She looks up at the Treatment Planning markets and then makes eye contact with the camera. "Legit to do that?" 

[Response by earbud: yes, she can at five-minute increments update the dilutant rate and resulting fluid excess based on the last five minutes worth of urine output. Oh, and they'll add another cookie to the currently-inactive diet order list. Does Merrin want to pick what kind of cookie.] 

(Merrin has at this point promised Kalorm, like, eighteen cookies in exchange for being "helpful" in various ways, though who knows how long it'll be before he can eat normally.) 

Kalorm's urine output is all over the place on the five-minute-chunks level of granularity, so some of the time Merrin will end up having to reduce the dilutant rate again and then use every other lever at her disposal to keep the filter pressure reasonable, but on average it's pretty decent? He's probably going to manage almost 100 mls of urine output this hour. 

He's also dumping a lot of protein, which is a major sign that the semi-permeable biomembranes of his nephrons (that the dialysis filter is imperfectly trying to replicate; the 'imperfectly' is why it eventually accumulates crud and clots up, which kidneys do not usually do) fell far enough behind on even basic structural-maintenance cellular processes, during the many hours of low circulation, that they are full of holes and leaking larger proteins that under normal conditions would stay in the blood.

And without intervention it's about to get a lot worse, because accumulated organ damage elsewhere is now cascading to affect that system. His creatine kinase levels - a key enzyme in muscle metabolism that finds its way into the bloodstream after muscle damage - are spiking rapidly; the damage was done slowly, over many hours of complete immobility and not-really-sufficient bloodflow to skeletal muscles, but especially those first four hours (and the potential crush injuries from being repeatedly slammed into a boat by waves are probably not helping). The cell death cascade is now proceeding further - it's a largely different set of pathways that the treatment protocol was not designed to block - and there's finally enough bloodflow to actually carry those byproducts back to the central circulation. It's a predictable consequence of the treatment protocol they chose, and an acceptable one, but it's likely to keep getting worse. 

His urine myoglobin levels (a heme-containing protein found mainly in skeletal muscle cells, that provides extra oxygen so that muscles can maintain a level of activity exceeding the blood oxygen delivery for a little longer before falling back on lactate-producing anaerobic metabolism, released into the bloodstream in large quantities when muscle cells die) are already twenty times what they should be and still rising, as his blood levels overwhelm the re-absorptive capacity of already-damaged nephrons. Myoglobin would normally be cleared quite quickly - though it might damage even healthy kidneys in the process - but hemodialysis is by itself ineffective at removing much of it, and they're expecting the levels to keep rising for a while, as damaged muscle cells finish a slow death. (Also, it's not great for the filter lifespan, and it would be really nice if they could stretch that out longer.) 

The Complicated Liver Replacement Module can handle some of it, but not fast enough. The plan is to set up a plasmapheresis circuit immediately after Merrin's handover, once the patient is pretty hemodynamically stable at this temperature; it would have been necessary anyway, there is inevitable tissue damage in a lot of non-brain places and that will set off an inflammatory cascade as his body notices and they still need to keep his levels of inflammatory cytokines from getting out of hand. 

Can the Complicated Liver Replacement Module team please max out whatever setting is relevant for this? The dialysis filter is still working, but Merrin suspects it's nearing the end of its functional lifespan, and she is not feeling very up for changing it, or honestly even for having someone else change it for her, it'll mess up her equilibrium here. Which is, to be fair, a deeply irritating equilibrium where she is constantly skating the upper limits of acceptable filter pressures, but at least she's used to it. 

They will probably have her replacement change the filter, yeah. It's not ideal - even with their level of infection-prevention precautions, manipulating very invasive machines is still a nonzero risk, and even now that Kalorm is warm enough to have immune function at all, they're deliberately suppressing some aspects of his immune system - doing their best to be selective, shutting down inflammatory cascades while retaining the capacity to hunt down bacteria in places they shouldn't be, but selectivity is really hard. And they have a lot of invasive sensors and life-support machines. Hospital-acquired infections approximately do not happen, and the markets still think Kalorm is, like, 50% likely to end up with one. (And more like 80% likely to end up with ocean-acquired pneumonia, despite the pre-emptive antibiotic treatment they threw at that problem.) 

(Which will be fine. Dath ilan also takes a lot of precautions - on a Civilization level, not just in hospitals - against letting antibiotic-resistant pathogens arise in the first place, or end up in hospitals. An infection will be treatable, but it will mean a longer hospitalization and slower recovery.) 

31.5 C. Nearly there. 

Kalorm's feet are now, if not quite pink, at least no longer blue. 

The pacemaker console is flagging that, where before the underlying electrical rhythm they were trying to suppress by pacing his heart was 90% abnormal, the software now thinks that his heart is sneaking in normal beats before the next pacemaker signal would fire. It's on adaptive mode, so in those cases it waits rather than try to make him have a double heartbeat or something, but there's still an increased risk that it will fire an electrical signal at a bad time and flip a normal underlying rhythm into something much worse. 

Merrin puts it on timed-thirty-second-standby to see what happens. (It's actually fine if the answer is "still an abnormal rhythm", her bypass machine is still doing most of the work of maintaining circulation and can if necessary do more, but this is in fact around the temperature where she would have expected a normal underlying rhythm to start coming back - unless they damaged his heart's electrical system with the mechanical pump, which is not impossible but fairly unlikely to have happened in just four hours.) 

Sinus rhythm! Heart rate of around 40, which would be abnormal at 37 C, but is within the predicted normal range at this temperature. It's a little irregular, slowing and speeding roughly in line with the ventilator activity. 

Eeeeeeeeeee good work Kalorm! That gets another cookie! 

"Switching the pacing to backup mode," Merrin says. (This means it won't do anything unless the software detects more than [set number of seconds] of asystole, in which it will alarm and start pacing at the backup rate, or unless it detects something else which is abnormal, in which case it will alarm MORE URGENTLY and give Merrin the option of delivering a defibrillation-level shock, since attempting to pace an underlying rhythm of v-fib does not super work.) "Uh, and can we get ultrasound imagery please?" The pressure sensor readings on the bypass machine from the shunts are not telling her everything about how effectively Kalorm's heart is actually contracting. 

Someone will do that. 

Kalorm's heart is not currently incredibly competent at pumping. This is pretty much what Merrin expected. His myocardium is probably still kind of stunned from the initial cardiac arrest and then spending the last sixteen hours in a really weird physiological state, and also they gave him a LOT of anti-arrhythmic drugs a couple of hours ago to try to get his heart to CHILL and stop it with the overexcited ventricular arrhythmias, and drugs that tell the heart to chill also weaken contractility.

They could probably, if they absolutely had to, coax his heart to maintain adequate circulation on its own by giving him different drugs, but they don't have to; cutting the rate of the continuous IV-infusion antiarrhythmics and waiting a few more hours is fine, they can keep him on the bypass for that length of time. 

The markets are predicting 20% / 50% / 80% odds that they'll be able to get him off the bypass in the next 1.5 / 3 / 7 hours. It's also going to depend on how his lungs are doing – they can hook up an ECMO circuit again if it looks like he'll be able to maintain circulation but not oxygenation, they still have the venous ports for that, but they want to reduce the number of invasive devices as soon as possible really. 

Well, how are Kalorm's lungs looking? 

Not amazing. Not actually as bad as you might expect, from the fact that he probably had like 200 ml of seawater in his lungs when they found him. It would have looked a lot worse in the 6 hours immediately after the near-drowning; they weren't able to suction all of the water out, and seawater is hypertonic and would have drawn more fluid from his tissues. 

If they had needed to ALSO subject his lungs to the increasing pressures and oxygen content it would have taken to meet his body's oxygen needs, especially during the latter half of the rewarming protocol as said needs were rising toward normal levels, that would have dealt a lot more damage, multiplying the inflammatory cascade already happening. But they didn't have to do that. They could afford to ventilate his damaged lungs gently, with juuuuust enough positive end expiratory pressure to keep alveoli from entirely collapsing, and with an oxygen content actually lower than atmospheric, minimizing the production of oxygen free radicals and resulting tissue damage. 

Even six hours ago, with various internal processes only slowly coming back online, his lungs still looked super soggy on CT scan or ultrasound. But lungs do know where fluids are supposed to be - not in the place where air is supposed to be - and his high sodium levels probably actually helped out in terms of absorbing that excess fluid back into the bloodstream and lymphatic system. Saltwater damages surfactant - the substance that reduces surface tension at the air-water interface of the moist alveolar surfaces and prevents them from collapsing - much less than freshwater. There's an immune response to the unexpected incursion happening, but much less than it would if his immune function weren't still partially suppressed. 

Though his lung secretions are, like, pretty gross. 

Ewwwwwwwwwwwwwwww lung snot. Merrin would vastly prefer liquid diarrhea over lung snot. (Well. Not in his lungs!!!!! That would be DEEPLY CONCERNING! But as a bodily excretion that she has to interact with more broadly, definitely.) 

The plan will be to go in with a bronchoscope and clean out his lungs really well before they see if, given higher ventilatory support, he can oxygenate well enough not to need extracorporeal help. But they'll do that after Merrin's handover. It's already been nearly sixteen hours, it's not urgent. 

...A lot of less-urgent things will now need to be dealt with. He still has a pool of clotted blood in his chest cavity that they haven't yet tried to remove, and a bone splinter they should deal with, and his broken arm is going to require a more complicated intervention than it would have if treated immediately, because some of the displaced bone probably didn't get adequate circulation. His gut is not moving at all, and the likely tissue ischemia - though hopefully not enough to full kill any of the bowel tissue and cause a perforation - is still putting him at high risk of gut bacteria having made their way across leakier-than-usual membranes, failed to be drained out by a not-really-functioning lymphatic system, and now hanging out in places they should not be. They were keeping his stomach empty with a gastric tube on low intermittent suction, and neutralizing acidity, but there's still a risk that the protective mucus-production failed and his gastric lining racked up some damage. He's going to need nutrition - especially protein, as his body tries to heal from really quite a lot of miscellaneous damage - and they super can't deliver it via the normal route for at least a few days while his gut figures out how to do its job again, so it's IV nutrition, which has its own risks. 

Merrin doesn't need to worry about any of that. Merrin just needs to get him up to 32 C (carefully, to minimize the chance of overshooting that point), get his hemodynamics vaguely under control at that temperature, and then hand off. 

31.7...

31.8....

31.9......

And she's there! 

Kalorm....is pretty stable here, actually? Aside from the constantly high filter pressures on the dialysis circuit (she is going to be hearing filter pressure alarms in her DREAMS for DAYS), the skyrocketing muscle damage indicators, and the fact that his kidneys are struggling very diligently to do a different job than the one Merrin would prefer they do, he's fine? His heart is doing around half the total work of maintaining a gorgeous blood pressure waveform at 105/60, and doing it consistently enough that she doesn't have to do much settings adjustment. His hands aren't quite warm to the touch, but their temperature is no longer startling.