I need a bit of help with the following scenario: My character is a very fit 26yo female (not sure if it matters, but she's tall/muscular, i.e. her heart is bigger, for what it's worth) and she ends up almost drowning when she gets knocked out while on an underwater demolition exercise. The explosive device detonates prematurely, and the explosion is big/close enough to cause unconsciousness (the explosion and the character are both underwater), but she's far enough to not suffer other injuries (and she's also wearing some protective gear). I'm still looking for info/asking around whether it's possible for an underwater explosion to cause unconsciousness without causing other physical injuries, but I haven't yet found anything definite (if anyone here knows, feel free to chime in). Anyway, since it's an exercise, her team and NCO are close in a rubber boat, ready to help (the NCO knows CPR and they have an automatic external defibrillator). Since the exercise takes place at night and in bad weather (on purpose), it takes a moment before the others reach her while she's floating face down. Her diving partner also gets dazed, but remains conscious. He reaches her in roughly 30 seconds or so. Their team mates dig them out of the water about 60 seconds after the explosion and the resuscitation starts between 60-120 seconds. She has probably inhaled some water (anyone want to hazard a guess how much?) during the explosion/the 30 seconds (or so) she spent unconscious underwater/face down. They start CPR immediately when they don't feel a pulse/notice she's not breathing. This is where I'm out of my depth (sorry!). What's the difference between cardiac arrest rhythms ventricular fibrillation, pulseless ventricular tachycardia, and asystole? What's more likely in such a situation? From what I've read, they don't defib asystole, but they do with the other two (do they use epinephrine with the other two as well?). If it's not asystole, I've understood that since the CPR starts in 1-2 minutes and they do have a defibrillator as well as people who know CPR, her chances of survival are roughly 80%. Now, how does a person's body react do defib? I doubt it's the dramatic, back-arching spasms of TV. If they use pads that stick to the skin, would they be placed on front and back or just on front? There's some waves, so would the tricky circumstances affect the placement of the pads/paddles? How many shocks does it usually take in such a situation (note: the effects of the explosion/KO have already worn off at this time, so she's unresponsive because of the stopped heart and lack of breathing)? When a patient wakes up from such a condition (after they get her heart going again), would she still have the water in her lungs or would she cough/puke it out during the CPR despite the stopped heart, like a reflex or some such? Or would the expulsion of water happen after a successful defib? Do they need to "get" the water out of her somehow, e.g. by turning her on her side or something? How long does it generally take for the patient to become lucid again to the degree that she knows her own name, what year/month it is, recognizes her team mates etc? What should the person(s) administering the CPR do as soon as she wakes up? Let her lie on her back or turn her on her side? When they get her to the paramedics, what would they do to her first? Put on an oxygen mask, an IV, something else? I don't need much, just a few details the POV character can observe before she's hauled into the ambulance. How big of a difference does it make whether she's inhaled salt or fresh water? If salt water causes bad complications and keeps her out of commission for long (e.g. longer than a few weeks), I can always change the location into a lake or some such. How long would she be hospitalized after such an accident? How long before she could return to active duty? Rough estimates are fine here. Also, when her CO goes to check on her (after she's stable etc), what "hospital gear" would she have on her, i.e. IVs, tubes up her nose etc? Btw, would what I've described her count as being clinically dead? Thanks in advance!
Your poor characters. If the shock wave knocks your head around you could get a coup/contrecoup brain injury, so yes. You take a breath, your lungs start to fill with water but even unconscious you could have a cough reflex (depends on the depth of the coma), but you would eventually replace the air in your lungs with water. With no pulse you wouldn't be inhaling either so no water would go in the lungs. Your timing's off. You get knocked out, it takes longer for you to stop breathing the water in: 4-5 minutes. Then the heart would stop. If you are having the heart and breathing stop right away, that would have to be a near lethal brain injury and recovery would not be just waking up because someone restarted the heart. Didn't this get answered already? And you can look them up. When the heart stops it is usually fibrillating at first. Think bowl of jiggling jello, not pumping any blood. Asystole refers to flatline, i.e. no jiggling. It occurs a few minutes after fibrillation if there is no CPR going on. And yes, you give 2 minutes of CPR before defibrillating if the rhythm shows asystole. You would give the epi, but All of those chances of survival change in a cold water drowning. They do jerk a bit, I've never seen anyone arch their backs. You should look placement of the paddles up, it's faster than describing it. A healthy heart, not stopped very long, one or maybe two. If the person's been underwater long they need to warm up first or it could take many. One thing people always get wrong about folks who have been knocked out is you do not wake right up. First, a quick knockout, the person is only out for seconds. That person wakes right up. But if you are out minutes or longer, you have a serious bruise on your brain and swelling occurs. People wake up groggy and sleepy for the next 24 hours or longer. Or they don't wake up for days and you have to control the brain swelling. You can't do CPR without turning the person over and draining the water out of their lungs. You use gravity and compressions to do that. Pneumonia would be a big risk after drowning from the residual water and crap in the lungs and salt water has more crap in it than fresh water, but some fresh water is dirty. Keep that in mind. Later for the rest.
Not sure if it's been mentioned, but a defib doesn't re-start a stopped heart, it only corrects a heart that's beating erratically. If her heart's stopped, then it's CPR, no defib. But yes, I imagine the first thing they'll want to do is get water out of her lungs first before doing CPR. EDIT: Correct me if I'm wrong, but wouldn't they pull her eyelid down and shine a light into her eye to check for brain damage (somehow the pupils being dilated or not indicates whether or not the brain had been damaged.)
Umm, this isn't right. Maybe I'm misreading your post or you don't understand the terminology. A fibrillating heart is not beating, rather the electrical activity is erratic, going from cell to cell in disorganized directions, not coordinated. The jolt from the defibrillator clears the slate so to speak allowing the pace maker node to fire off a coordinated electrical current which the heart needs in order to pump. All heart muscle cells have the ability to contract on their own without a pacemaker. The pace maker cells normally fire first, the current spreads out across the heart in a pattern that results in a coordinated pump action. When the heart is fibrillating all the cells are just contracting willy nilly. It looks like jiggling jello, literally. It's not 'want', it's have to. You can't get air exchange through water filled alveoli. One would check pupils and it does show level of consciousness. See the Glasgow coma scale
Excellent info, thanks, Ginger! Looking forward to Pt.2 since the first part already provided info that'll help us avoid catastrophically embarrassing mistakes. I seem to torture them an awful lot, don't I? Oh well, they're tough, they can take it. Awesome; that right there is the kind of mistake that would sacrifice the realism of the scene, something we want to avoid at all costs. So let me get this straight: if her heart stops, she won't be inhaling water, i.e. no drowning as such. If her heart doesn't stop and she's just unconscious, she will keep breathing in water for 4-5 minutes before the heart stops, but if we don't want her waking up within seconds and swimming to safety, the head injury needs to be severe. A scubadiver said that if you've been unconscious underwater for 4-5mins (apparently many pass out before they start inhaling water), chances of survival aren't all that good and permanent damage is likely, so that's pretty much out. If I've taken everything into account, it seems we have to pick one of three options: -scratch the stopped heart and make her "just" almost drown due to another reason than unconsciousness (e.g. getting stuck underwater so that her partner can't free her before it's almost too late) because being unconscious long enough to drown requires serious head trauma with serious repercussions -do something that does cause the heart to stop, but since I have no idea what would even cause that in this situation, that probably won't be an option -do something else entirely* It did? Now it's my turn to be confused. And I did look them up, but... to be perfectly honest, a lot of it flew over my head. However, seeing as how I don't know what would cause her heart to stop in the first place, it doesn't really matter after all. This happens during summer in the Balkans, so the water is pretty warm, but of course nothing's set in stone yet, so if e.g. it's more realistic she'd survive such an experience in cold water, we could still change it for winter/fall/spring. That's just it: I did look it up, but I found two variations: one where one paddle goes on the right side of the upper back while the other paddle goes to the left side and one version where the lower paddle is the same low left, but the upper paddle is on the front as well, basically on the right pectoral. From what I read, some appear to favor the front/back combination, but I was just wondering if it was more difficult to do in a rocking boat in a rainstorm than the front/front variant. If they need to keep her on her side in any case, then the front/back option might be better if it really is, well, better. Hmm... is it realistic that she comes out without permanent damage if the KO is bad enough that she's out for a few minutes? I know there are always exceptions to every rule, but I wouldn't want anything too far-fetched. Of course, being groggy/disoriented to the level of being incapacitated/unable to save herself from drowning would be just as "useful" as being fully unconscious for the same amount of time. *I found this info about underwater explosions and their effects on humans and, well, it's starting to look that whatever causes the near-death experience can't be an underwater explosion: if they're so incredibly lethal, I don't think it's possible for her to survive a pressure wave strong enough to knock her out without suffering severe lung damage, ruptured blood vessels, burst bowels etc. I'll have to consult a SEAL friend who's specialized in UWD, but it'll take some time before he's available again. Dang it, this could've been such an exciting scene if reality didn't keep messing things up. Just goes to show that "good" ideas aren't always all that good...
My bad, the thread on the cardiac rhythms was one started by @Alesia: https://www.writingforums.org/threads/what-does-a-heart-monitor-do-during-a-cardiac-arrest.131753/ I can still only answer this a piece at a time. When I find myself answering with an hour long research paper I burnout. So clarifying the water in the lungs: At some point underwater you run out of oxygen and pass out whether you were hit in the head or not. When that happens the reflex to breathe overrides the reflex to cough. When people drown, water is found filling their lungs. When they die first the finding is no water in the lung. Cardiac arrest differs from a coma. With cardiac arrest breathing ceases. If the arrest is first, no water in the lungs. In the scenario you are describing there would be. The cardiac arrest would occur after the woman was underwater. And with drowning you MUST get the water out of the lungs before you can do CPR. As for the Balkans being warm in the summer, water in a hot climate can be ice cold if it is from glacier or snow melt and moving fast. So you can write the story any way you want, warm or cold water. Even with snowmelt, if the river is running slow and it is shallow it can warm up. Water temperature doesn't correlate with the air temperature, it correlates with the source of the water and the speed and depth of the flow is there is any. If it's a lake then it depends on the source of the lake's water. More later.
Re the water temperature: when we were kids we used to visit my aunt in Bullhead City, Arizona. The Colorado River runs next to the city. The source of the Colorado is hundreds of miles away in the Rocky Mountains. Despite that distance and the extreme heat in the summer in Bullhead City, the river was almost too cold to swim in and though we went boating we almost never went swimming in the river.
Thanks for the heads up, I'll check that out too. No problem, I'm just grateful you're taking the time to answer my questions. Roger that. I'll have to look into possible causes of cardiac arrest (I think the underwater explosion would do that, but she'd suffer too much other damage as well to pull through) that might be usable in a situation like that if there are any (except the actual drowning, which, again, seems like a risky option if I want her up and running in a few weeks). The original idea was to have it happen in the Black Sea during summer which, while chilly at night, isn't terribly cold (the dive isn't deep), but I'll have to research larger lakes in the area because there needs to be an island large enough to house a large building (the size of your average prison) in that body of water: the island is their destination and the need for UWD comes from the old-fashioned underwater mines that surround the island, but I suppose everything can be still changed, so we could also figure out some way to move it all higher up where the water is colder or change the date from summer to winter. Awesome.
So sorry for not answering this earlier, there were too many questions at once and I didn't have the time to answer them all. Just looking through the follow-up, with respect to defibrillator paddles, actually, a lot of doctors don't position them correctly, and this is especially true for the (patient) left one. When you are looking at the patient face on, the paddle on the left hand side of their chest (your right) needs to be quite laterally placed, far away from the midline, about 5cm from the line of the armpit, under the breast, over the heart's apex. The paddles need to be sufficiently separated, which doesn't happen as effectively when that side is placed to medially (closer to midline, as you often see). On the patient's right (your left) the paddle is closer to midline and higher above then the other paddle, placed in mid-clavicular line, about 10 cm below the clavicle. Paddle placement is even less exact then the ecg electrode placement, especially when the defibrillator is used in an emergency. But the surface area of them is much larger. The important thing to remember is to sufficiently separate them and not be too shy about placing the left one laterally. I think, because we can palpate apex heart beat more medially, that we have an urge to place the paddle there. Generally speaking, it's not a deal breaker, but the correct placement is preferable. As with everything before, you aren't writing a resuscitation manual, nor are you a doctor yourself, I don't think you need to worry too much about knowing and including lots of details. All these concepts take many years and lots of practical experience to master, and no matter how hard you try to fully understand it all, it will be difficult to achieve. I think it's best not to focus on tiny medical details too much, or at least pick and choose a few, to inject reality, but don't let it restrict your imagination You can always introduce a rare current into your warm sea, or vice versa, most of the time you can make whatever it is you have imagined, work. It doesn't have to be 100% realistic, it can't be anyway, since you are writing fantasy.
Thanks a lot, @jazzabel! And there's no hurry, I'm just doing research for a future scene, not one we're writing right now, so don't worry about that at all. And yeah, that's essentially what I'm trying to do, whether it's stuff I know about, like gun-/fight -related things or something like this that I don't really know at all. In both instances, I gloss over most of the small stuff, but I do want to do exactly what you suggested, i.e. inject a few small details here and there to increase the sense of realism in the scene. What's important to me is to know the proper procedures in general so that I know how to choreograph the scenes. This is a stupid example, but it serves the point: I need to know that when you use a defibrillator, others are not supposed to touch the patient when the machine produces the shock. If I didn't know that, I might "accidentally" write it so that while one person is using the defibrillator, another is still administering CPR and doesn't let go of the patient during the shock which, of course, wouldn't add up from the perspective of realism. In any case, this scene is a tough one to "compose," and I'll need further imput from the SEAL guy as soon as he has the time because there are so many bigger details that I need to know to choreograph the scene. I mean, before he pointed it out to me, I hadn't even realized that such divers always work in pairs in such exercises/missions, and it makes sense too, doesn't it? I just hadn't taken it into consideration and the first draft turned out to be totally unrealistic because of that. I'm just glad you guys are here to give me a hand because while the story is fiction, I want it to be realistic too. To the point of still being readable/enjoyable, that is.
I can only answer your question about unconsciousness. An explosion itself never renders anyone unconscious. It's the impact that does. So if she's underwater, I doubt an explosion that doesn't physically harm her could render her unconscious HOWEVER, the momentum in the water could shove her into an object onto which she knocks her head and is rendered unconscious. That's the only scenario I can think of. Also I noticed they started CPR and THEN noticed she has no pulse and isn't breathing. This is the wrong process for CPR. As a trained first responder (and a diver) I can tell you with 100% certainty that you can ONLY perform CPR if the patient isn't breathing and doesn't have a heartbeat. If any of these are present, no matter how weak, performing CPR would make things worse. So in your story, make sure that FIRST they check that she doesn't have a heartbeat or isn't breathing and only THEN do they start CPR. They can't start CPR right away and then say "crap! she's not breathing!". Any experienced medical professional will tell you it's inaccurate and not how CPR works. As for the medical terms about the heart, a simple Google search would suffice. I'm not a doctor so I can't tell you the specifics you would need to know. Hope this helps!
From the link I posted above, I got the same impression: the primary blast injury caused by the shockwave (made much worse by the character and the explosion being underwater) would cause extensive damage to her if she's close enough to lose consciousness from the PBI, even death. It does, thank you. Could I PM you sometime later about these things (providing first-aid & diving)? We're not writing this scene right now, but will sometime in the future and we could use all the help we can get. Naturally @KaTrian and I would be more than happy to return the favor anyway we can, e.g. by beta-reading your ms or something.
check out youtube videos on defibrillation for a realistic look at how the body jerks (it's a small jerk). There's one of a guy who is zapped on the beach - also note what happens to his eyes when he comes round. There are loads of medical websites but when I was researching something similar, I found that the best thing to do was research each individual thing and see where each part overlaps. The heart has two distinct beats per pump, one is the heart sucking in/filling up with blood (diastole) and the other is where the heart is emptying as it's pumped out of the heart and around the body (systole) Blood pressure refers to the pressure of the heart as it pumps so a blood pressure reading of 120/80 means that the systolic (emptying) pressure is 120 and the diastolic pressure (filling) is 80 A good BP range is between 120/80 and 140/90 If you look up: hypertrophic cardiomyopathy, left ventricular hypertrophy, paroxysmal atrial fibrillation, Arrhythmia you will most likely find which ones need defibrillation and which don't. I've taken this info form my own research notes so the rest of the stuff I have written down pertains to something other than what you are looking for. Hope this helps xxx
