1. Alesia
    Offline

    Alesia Pen names: AJ Connor, Carey Connolly Contributor

    Joined:
    Mar 19, 2013
    Messages:
    998
    Likes Received:
    251
    Location:
    Knoxville, TN

    What does a heart monitor do during a cardiac arrest?

    Discussion in 'Research' started by Alesia, Apr 8, 2014.

    Like the steady "beep... beep... beep" on a hospital room hear monitor. If the patient goes into cardiac arrest does it flatline? Speed up? Slow down? Become erratic? I'm assuming there is an alarm of some kind that would sound off as well.
     
  2. mrieder79
    Offline

    mrieder79 Not a ground squirrel

    Joined:
    Jul 3, 2013
    Messages:
    400
    Likes Received:
    280
    Location:
    Uyumbe
    *post deleted*
     
    Last edited: Apr 8, 2014
  3. GingerCoffee
    Offline

    GingerCoffee Web Surfer Girl Contributor

    Joined:
    Mar 3, 2013
    Messages:
    17,604
    Likes Received:
    5,877
    Location:
    Ralph's side of the island.
    No, you don't flatline for several minutes of no circulation at all.

    Several things can happen, all of them involve a heart not pumping blood.

    Ventricular Tachycardia: Heart beats about 300/minute, no time to fill, you need CPR if you cannot slow the rate down but typically you inject drugs. Rarely some hearts will pump blood during V-tach but it is still an emergency. And sometimes people will have runs of V-tach with a beating heart in between.

    Ventricular Fibrillation: most common and what you see when V-tach goes too long. The heart looks like jiggling jelly (I've seen a couple during open heart surgery) and the monitor looks like static.

    Electrical Mechanical disassociation: The monitor looks like the heart is beating but it's just the electrical signals and the muscle isn't moving.

    There are some other miscellaneous rhythms like complete heart block where the atria beats but the ventricle only fires off random beats that don't provide a fast enough rate for life.

    After many minutes of fibrillation you get a flatline. A flatline is not typically compatible with shocking back into a rhythm and usually we give a bunch of drugs and two minutes of chest compression before trying to shock the patient.

    This is helpful:
    http://www.emedu.org/ecg/crapsanyall.php

    #30 is V-tach and #74 is V-fib.
     
    Last edited: Apr 8, 2014
  4. Alesia
    Offline

    Alesia Pen names: AJ Connor, Carey Connolly Contributor

    Joined:
    Mar 19, 2013
    Messages:
    998
    Likes Received:
    251
    Location:
    Knoxville, TN
    So how would you go about describing the process? Is it a matter of the patient is talking one minute, then they just go unresponsive the next? The way I have it written at present is something along these lines:

    1.) Patient goes unresponsive. Like one minute she is fine and taking to someone, the next her eyes glaze over and her expression goes blank.

    2.) Multiple alarms sound on what equipment they have. Monitors everywhere start going berserk.

    3.) Medics begin CPR. This is a poorly constructed field hospital -- no defibrillators or drugs are readily available. This patient is going to die, but they give it their all anyay.

    4.) Flatline...
     
  5. GingerCoffee
    Offline

    GingerCoffee Web Surfer Girl Contributor

    Joined:
    Mar 3, 2013
    Messages:
    17,604
    Likes Received:
    5,877
    Location:
    Ralph's side of the island.
    If you are writing an actual death, I'd focus on the emotion and action and worry less about the technical things.

    On the other hand it's always annoying to see blatant med errors in a book or on screen. When you are pumping on the chest, the movement shows on the monitor. In between you'd see that squiggly line in image 74. After some time, few minutes, you'd eventually see that flat line.

    What is going on is the body's electrolytes are getting more and more out of whack. When you can't exhale CO2 accumulates putting the body into acidosis. The electrical activity of the cells has a narrow pH range. In fibrillation you have disorganized electrical activity. The muscle cells in the heart are firing but there is no coordinated pacemaker. As the pH lowers (CO2 is acidic) eventually it gets too low and all electrical activity ceases. That's how you get fibrillation before flatlining.
     
  6. jazzabel
    Offline

    jazzabel Contributing Member Contributor

    Joined:
    Jan 5, 2012
    Messages:
    4,273
    Likes Received:
    1,666
    Well, in the field hospital, if they don't have the defibrillator, it's unlikely they'll have any monitors at all. Defibrillators these days are tiny and portable and civilians can be easily taught how to use them (basically they are automated and shock only what is shockable), so I'd imagine if they had anything, they'll have that.

    No self-respecting field medic would have loads of tubes and monitors and no basic kit. You have to have some fluids, antibiotics, pain killers and emergency drugs, such as adrenaline, amiodarone, lignocaine etc. Otherwise monitors but no drugs makes no sense to me.

    Depending on what's wrong with the patient, they can suddenly collapse, but much more commonly, the problems are anticipated (since they're already being monitored) theres a plan of action in place, and usually people are symptomatic for a while before they collapse.

    There are lots of different reasons why vital signs monitors can sound an alarm. Depending on the monitor, it can measure all sorts of parameters, from blood pressure, heart rate, heart rhythm (ECG), oxygen saturation, breathing rate etc. The sound is typically silent if everything is ok, alarm sounding off only if one of the parameters changes into something abnormal. The alarm can go off in the machine itself, when it sounds a bit like alarms on the new fancy fridges when the temperature is too high, or it can be hooked up to the nurses station computer and alert there directly.

    You don't have to have a heart 'stop' for the cardiac arrest to occur, but whatever rhythm heart has, it is ineffective at pumping the blood around the body, so collapse and loss of consciousness occurs soon, unless something can be done to revert the patient into the normal sinus rhythm. Any severely abnormal rhythm, such as acute atrial fibrillation, ventricular fibrillation or ventricular tachycardia, can leave patient feeling awful (chest pain, sinking feeling, nausea, grey in the face, crashing blood pressure etc) and if they get VF they'll most certainly collapse. The causes are many, from primary cardiac problems, to blood loss, infection, medication, electrolyte imbalance, etc. Depending on the causes, the treatment can vary, but establishing effective oxygenation and circulation are paramount. For this we have the CPR, intubation, ventilation or oxygen masks, certain medicines (adrenaline, amiodarone, lignocaine etc) and defibrillators. There are other more specialised techniques, but the ones I mentioned are most common.

    About the defibrillator, if you are trying to bring the patient's heart back 'on line', the flatline aka asystole is not helped in the slightest by shocking it. This is in contrast to what you get tp see on tv when flatlines are commonly shocked, to the facepalm of every single doctor who is watching. The so called 'shockable rhythms' aren't a flat line, and typical ones that might lead to death are ventricular tachycardia and ventricular fibrillation. Otherwise, the 'flat line' if acute, is best treated by chest compressions and IV adrenaline.
     
    Last edited: Apr 8, 2014
  7. Alesia
    Offline

    Alesia Pen names: AJ Connor, Carey Connolly Contributor

    Joined:
    Mar 19, 2013
    Messages:
    998
    Likes Received:
    251
    Location:
    Knoxville, TN
    I need to clarify a bit, I think. This "infirmary" (if you can even call it that) is basically a bedroom in an abandon house. The year is 2050 and the United States is locked into a massive series of civil conflicts. What drugs/equipment they have are scavenged from abandoned clinics and bombed out hospitals/crashed ambulances. Here's what they have available:

    Oxygen tanks/masks. No intubation equipment.
    A portable ECG
    Epinephrine
    Atropine
    Morphine
    Aspirin
    A few Surgical Tools
    Bandages
    (I suppose I could add in a set of paddles too!)
     
  8. GingerCoffee
    Offline

    GingerCoffee Web Surfer Girl Contributor

    Joined:
    Mar 3, 2013
    Messages:
    17,604
    Likes Received:
    5,877
    Location:
    Ralph's side of the island.
    I think @jazzabel was right about the monitor and the defibrillator typically going together, but if the equipment was scavenged, it's very realistic they would have been two separate pieces of equipment. And you could always have a broken defibrillator.

    Here's a good link with some simple explanations on basic drugs for cardiac arrest:

    Understanding the drugs used during cardiac arrest response.

    Pay attention to which ones you can just inject and which one's you'd hang a drip and need to carefully control the rate.

    The three key actions are getting oxygen to the brain and heart muscle, restoring and/or controlling the rhythm, and correcting the acidosis.

    Aspirin is useful for an MI that is caused by a clotted off artery in the heart. It's not something you'd worry about in the setting you are describing. It might be given early on when just chest pain was occurring and an MI was suspected.

    Morphine is used to relieve pain, but also because that pain adds strain on the heart.
     
  9. jazzabel
    Offline

    jazzabel Contributing Member Contributor

    Joined:
    Jan 5, 2012
    Messages:
    4,273
    Likes Received:
    1,666
    They also need intravenous fluids. It could technically be made up by adding salt to sterilised water (to make up 0.9% Normal saline solution). Emergency treatment would be almost impossible without some means of replacing volume. So I'd be looking for a reasonably reliable supply of IV fluids and all the equipment needed for administering IV medications such as needles, syringes, venflon/jelco/ IV lines, drips. A lot of injectables need to be made up with water or saline, so this is another reason why we need fluids.

    They could have only a few kits, they don't take up a lot of space. Hospitals have mountains of this stuff so if they have access to hospital supplies, IV equipment, gauzes, bandages and dressings are usually most abundant of all supplies. This would also be useful for blood transfusions, and for drainage, (such as pneumothorax or haemothorax, both of which are common traumatic injuries) or even to serve as a catheter. Some of this could be fashioned from stuff they find, but some needs to be proper medical equipment.

    The list of meds looks good, I'd definitely add in some Penicillin or similar, and antiseptic cream, maybe something for the burns as well (Silvazine and other silver based creams are very very useful and they last for ages), but the creams could be made up of they have access to some medicinal plants and someone with a knowledge.
     

Share This Page