Many thanks

thanks so much!!

Thanks!

Thanks so much, Phil! Glad to answer questions

thank you so much!

Excellent question. Everything you say is true. We saw the experiment as validation of the mechanism, not as a model for a clinical response. To go to the next level, the first question is the one you raise. Your suggestion of cardiac needle is very relevant , and probably the only viable route. Don’t know if anyone has done this

@@uclamodelingclass3003 I was there when King County Medic I, Dr’s Eisenberg and Cummings etc, and those manufacturers along Bel-Red Rd first trialed bread boards AED units in a suitcase with us. FF’s, EMT, not medics, manual defibbers, we were used being used for trials. Of course they gave us the ‘why’ talk. After all they were adding to our aid kit, o2 kit, Lifepak 5 ekg/recorder unit/ manual defib unit, portable radio, these units, first with a long 120vac cord, then next motorcycle lead acid battery powered 28 pound units load from unit into home. Talk. Reiteration of importance of citizen cpr, and time to get first shock on-board. They didn’t talk of putting these things on airplanes or office lobbies. They talked of experience around the country with trying to get emt’s to deliver shocks. So they played us tapes. They’d get on scene and while not as drilled as us, get cpr taken over by FF’s, leads on, paddles gelled and capacitors charged. Assess. First it wasn’t defibber in charge, VF, clear, apply shock. It was committee discussion time. In one case a group in southern Iowa repeatedly stopped for assessment, agreed VF, restarted cpr, wash, rinse repeat for NINE minutes before applying shock. Of course finer and finer VF, all that chemistry going bad, etc., pt did not survive. My point. It’s one thing to say we’re going to replace defib with an IC stick. It’s one thing to provide fine tools. It’s another to actually get people in the field to do what they find to be a scary procedure. Manual defib was NOT slower or less accurate in competent hands. After Lifepacs with both capabilities we stayed with manual for years. Why? The tapes showed we got first shock on board faster than the automatic unit, with its two x out of three 3-second assessment cycles. They went AED for EMT’s because they wouldn’t shock based on reading the strip. I’ve never done an IC stick but I’ve sure seen them a lot. I can’t imagine you’re going to get success if that is your intervention model. In the end are you going to get Bob or Susan on the floor of someone’s living room to push that long needle into the heart.

I was an EMT before there was an accepted state or national certification process for EMT’s to carry out defibrillation. Fortunately I worked in King County, Washington State. So I carried a prescription written by a licensed physician that allowed, or required, me to deliver the shock he mentions, if the circumstances in the training were met. Much (all?) of the field trials on number and strength of shocks were carried out in King County. I can discuss further if you like. So when firms first stated producing prototype AED’s, we were the initial users. Similar to previous trials, it was 90 days of AED, 90 day of manual defib. First unit had a button battery for the clock, and a long 120vac cord. Built into a common suitcase. Second later unit from a different firm, used a lead-acid battery, like you might find on a 125cc motorcycle. Unit weighed 28 pounds. During CPR where an EMS system is in place it is axiomatic that paramedics start an IV of D5W explicitly so that meds can be introduced into the patient easily. Circulation is provided by the CPR compressions. Paramedics in the field also as indicated also commonly carry out direct IC stick. The most common medication I’ve seen used is epinephrine. Are there others? I’m out of date, and I’m no paramedic. What is the key currently to success? Everyone likes a TV hero, but that and $4 will get you a cup of coffee. An effective system, one that embraces constant improvements is the key, with many players. Perth, Western Australia, has four-year degreed, excellently educated paramedics. If your loved one goes into cardiac arrest, you want it to be in suburban Seattle or Seattle itself, instead of Perth. Much higher rate of survival. Except for a higher percentage of citizens trained in CPR, and maybe after five decades, an acceptance that CPR is a normal thing, I don’t think any level in King County is better educated or trained than in Perth. King County has a better, seamless system. I’ve continued compressions right into an operating room in hospital, so an intracardiac pacemaker could be implanted. There’s complete expectation that this guy who was driving a fire engine 40 minutes earlier will operate effectively as per of a team that is in its third evolution of participants, by now with anesthesiologist, RN’s, and a cardiologist.

absolutely correct that this is a limited exercise, in that there is no contraction at all in this model, let alone E-C coupling. And it is also correct to point out that the model has no degradation of ion concentrations over time, which would of course happen in real VF. So this is a highly idealized example.