COCHRANE + LUCAS = NO LOVE

iPhoneIcon_BigCochrane does it’s usual thing. Looks at available evidence, then concludes more evidence is needed, and that the use of mechanical CPR isn’t supported by this Cochrane review. The problem is that they’re missing the point of mechanical compression devices.

Running to stand-still
We have written before in CPR: Man vs Machine: 1-1: Mechanical Compression Devices are not for better compressions – they’re for logistics. Facilitating transport, freeing up hands, making the patient less crowded, facilitating angio/PCI on arrested patient and so on. THAT is where LUCAS and friends come into play.

So for this, the comparison should be between LUCAS and bad – or even abscent – manual compressions in the back of an ambulance racing through the streets. LUCAS will win this match.

It is also important to have good data that Mechanical Compression devices are working properly, are reliable and don’t cause harm – and in our opinion, we’ve got good enough evidence for that now. There is no point in adding MCDs to try to improve the manual compression show. It would be great if MCDs were better than manual CPR, but it might just be that we’re already at the limit of efficiency from closed chest compressions. This might be as good as it gets.

The way forward
Most cardiac arrests are solved the old fashioned way – and should be. To step it up, open chest cardiac compressions might be the answer – or even better: hooking selected non-responders up to ECMO in ED.

Mechanical compression devices aren’t for every arrest. But Cochrane or no Cochrane support, for transport and other logistical challenges, LUCAS and friends can still be good friends to have.

Mechanical versus manual chest compressions for cardiac arrest, Cochrane Database Syst Rev, 2014.

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12 Responses to COCHRANE + LUCAS = NO LOVE

  1. Vince D says:

    We agree about all things critical-care like 99% of the time and I hope you know I love your site, so sorry in advance for the rant…

    You raise some valid points about the role of MCD’s being an alternative to manual CPR and not an improvement upon it, but I might might play the devil’s advocate and argue that they are worse for logistics than traditional compressions. Instead of one provider focused on a simple manual task, performing compressions, you now have multiple providers trying to work together to set up the machine and get it started. Many places have a moratorium in place stating that mechanical devices cannot be placed during the first 5 minutes on-scene for this reason, but there are plenty of other that don’t. So instead of focusing on good compressions and early defibrillation, the current hallmarks of a good resuscitation, crews will be more focused on getting their toy working and troubleshooting whatever issues crop up.

    You also say it frees-up hands, but does it really? You still need someone to run the machine, and really, that person should probably be dedicated to watching it to make sure it is working properly and hasn’t become displaced. I’ve also never been to a CPR where I thought, “You know, I wish I didn’t have to have someone doing compressions so that I could add yet another person to the crowd of prehospital providers standing around and watching.” What are we freeing up hands to do? Draw up medications that don’t improve outcomes?

    True, they’re probably preferable if you have to move a patient in cardiac arrest, but the need to do so should be diminishingly rare. Medical cardiac arrest is a prehospital game with little to be offered in-hospital at huge costs; be it monetary, distraction from the resuscitation, or patient and provider safety during transport.

    Where we do agree is that they have a role in patients either going to PCI (though outcomes are still poor) or as a bridge to ECMO (not happening in my town for at least 20 years). However, the simple fact is that several large studies have been published (and a new one just came out) and none have been able to show any outcome benefits. If these logistical benefits that some argue for really made a difference, don’t you think we’d be able to see it by now? Or, if there’s really only a very limited scope of settings where MCD’s matter and thus we won’t see a signal, are they really offering that much over manual CPR to warrant the cost of purchasing and training required to get these out in the field in large numbers?

    Or are we just going to let them keep doing studies until one finally comes up positive?

    Who am I kidding, these are medical devices; all they need is to show equivalence and every ambulance across the developed world will stock one. The battle has been lost. Able to cite “equivalence,” manufacturers will then go on to imply or even outright state that their MCD’s improve outcomes for just the reasons you state. For more, see this: http://millhillavecommand.blogspot.com/2014/03/we-had-lucas-save-no-you-didnt.html

    • Thomas D says:

      Vince D, awesome comments, and good points! I very much agree with your views. Thanks for commenting – I’ll update my answer soon.

    • Thomas D says:

      I completely agree with your comments on LUCAS not saving lives as such. I believe in the manual compression show, as outlined in our LINC trial post: http://www.scancrit.com/2013/12/03/man-machine-1-1/

      For cardiac arrest, establishing good basic CPR always comes first! It comes before advanced airways, iv access, mech CPR, art.lines and all that. Early, good, basic CPR is what saves lives!

      Now, after that, advanced techniques can have a place. Pushing the envelope to get better results down the line is important. How much money and resources we should put into that is another question. Transporting patients in CA gives an advantage to mech CPR. Transporting people in persistent CA would only be indicated in young(ish) previously healthy patients arresting close to hospital. But these are rare cases, and I don’t know if the investment is ‘worth it’. But it does make transport better/easier/safer.

      For freeing up hands, I think urban areas, often with lots of responders, are different from rural areas, with few ambulance responders. Running a code with only two providers isn’t optimal. I feel three is needed, and four can be good too. Then again, putting on the LUCAS quickly when being only 2 providers sounds like a difficult task too.

      On pushing the envelope, I would argue that you need time to do these CPR+PCI or CPR bridged to EMCO for some time to get the best results these techniques can give. You need to work out the logistics and how to do it right, and you then need to work out which patients to include/exclude. New techniques take time. Just like laparoscopy or any other new tech advancement. Even in the end, you might find there’s no extra benefit there, but as long as the rationale is good, I think it should be given some time to prove itself. How much time? That’s up for debate.

      In our hospital, we don’t see LUCAS very often. I only see it dragged out for no-ROSC arrests going to PCI. And I don’t see a big need for it outside that.

      Thanks again for your great comments!

      • Vince D says:

        Thanks for the response!

        I could definitely see an argument being made for LUCAS/AutoPulse if you follow Simon Carley’s line of thinking in this recent post: http://stemlynsblog.org/ed-need-matt-parker-st-emlyns/
        It seems to fit well with what you and a couple of others I highly respect describe as the right way to implement CPR devices.

        If folks are going to do that, however, they better also be serious about the other aspects of resuscitation (good early CPR, no intubation, early defib, team-based resus, simulation, etc…). Gordon Murray didn’t just buy a titanium tool set for the car and call it done; that was only a small part of the much larger package.

        My little group has been discussing mechanical CPR a lot over the past two weeks and my current stance is that I don’t have a problem with it if “high-performing” EMS systems are the ones implementing these devices. By reaching that designation with manual CPR they have proven that they understand what’s important in a resus. What I worry about, however, is the “me too” mentality that is sure to follow; with mediocre or poor-performing systems implementing CPR devices as an attempt to work around their lack of training and poor outcomes. It’s situations like that, which far outnumber the “high performance” groups we have in the States, that have me pushing back against mechanical CPR.

        My thinking is that if you can’t do excellent manual CPR, these devices aren’t going to do your service any good. It makes superficial sense they they could offer better compressions than a lot of prehospital services are offering, but if those providers can’t understand the simple mantra of, “push hard, push fast, don’t interrupt,” then they are also going to fail when it comes to the more complex task of setting up and running these devices.

        • Thomas D says:

          Again, I very much agree with your points! Thanks for well written comments! They bring an important extra emphasis to the more sceptic view of MCDs. And like we’ve written earlier, MDCs are certainly not the holy grail of CPR, but might have a role in some settings.

          Like you say: early, good manual CPR should always have priority. By doing that, most of the patients we can bring back from cardiac arrest will already have ROSC before MCDs or any other fancy tricks come into play.

          Thanks for sparking thoughts and debate, Vince. It’s very much appreciated!

  2. Brooks Walsh says:

    Vince, those are some novel and trenchant thoughts! I especially appreciate your insight that the MCDs don’t really “free up” anybody at an arrest. Frankly, if there isn’t at least one person assigned to constantly monitor/adjust the MCD, then I would have serious concerns about the priorities of that resus team.

    Stepping back from the discussion somewhat, the debate shouldn’t be about finding the “right” place for the MCD – it’s about outcomes. We have good outcomes data for a number of interventions in CPR (aggressive community outreach, CCR-style CPR, delayed airway control), and we should focus on those.

    Yost 2012 demonstrated the risk of fixating on MCD placement, with interruptions in CPR ranging from 25 to 61 seconds! It’s great that many EMS systems have practiced hard to be able to deploy an MCD quickly, but we got rid of intubation in the first minutes of CCR for the same reason – too many intubators thought they were plenty fast. They weren’t, and they were harming patients as a result.

    Yost, et al. “Assessment of CPR Interruptions from Transthoracic Impedance during Use of the LUCAS™ Mechanical Chest Compression System.” Resuscitation 83, no. 8 (August 2012): 961–65.

    • Thomas D says:

      Agree. It is important to stress that early, good, basic CPR is what brings most people back. No tubing, no MCD no nothing before good, basic CPR is up and running. When basic CPR is running smoothly, you have a few moments to think about what your next move should be.

      Those are also some great comments on the CRM of cardiac arrests, and how to set up for success. In the same category as MCD and intubation are also iv access and drugs: they misplace the team’s focus and hinder the initial basic CPR. You always need control over basic CPR first. I think we often forget this, and whenever I get called to a code, it’s easy to see if the team focused on the basics first – or if they want to do everything at once. Structure vs chaos.

      Continuous training of the important basics must be a priority. But that shouldn’t stop us from searching for new and novel interventions that might help CA patients, and where they might fit into the chain of survival.

  3. ResusRobin says:

    Thanks for re-igniting the debate. Coming at it from an in hospital perspective I’m not convinced by the value of mechanical CPR (LUCAS or Autopulse) in circumstances other than if manual CPR is nigh on impossible e.g. to facilitate PCI

    To date comparative studies in humans have demonstrated conflicting results. If we look for equivalence between mechanical CPR and manual CPR surely the question we must ask how good is the manual CPR that the device is being compared against?

    If we use for example the recently published CIRC trial (1) .This large multi-centre prospective randomised control trial demonstrated statistically equivalent survival to hospital discharge. The devil of course is in the detail. This was a pre-hospital study where patients were randomised to receive either Autopulse or manual CPR from the point of enrolment, during transport, to arrival at hospital. The quality of manual CPR was measured in terms of hand off time (flow fraction) and compression rate. Crucially the period of investigation included transport to hospital where we know quality CPR (rate, depth, recoil and flow fraction) is difficult to achieve.
    The authors are to be commended in delivering a protocol with standards of adherence which meant flow fractions of 80% in the control arm. However, recoil and depth were not measured. So we are left with a study of mechanical CPR vs manual CPR of indeterminable quality. Likewise, the PaRAMeDIC(2) trial, with results expected in May does not measure the quality of CPR. Our instinct and experience tells us that the quality of manual CPR in the back of a moving vehicle is likely to be below recommended standards. Mechanical CPR is as good as this?
    When deciding to employ these devices the considerations must be clinical efficacy, safety and cost. Mechanical CPR may make CPR in transport safer but I’m not convinced yet that it’s anyway as good as high quality manual CPR.

    References:
    1. Wik L et al (2014) Manual vs. integrated automatic load-distributing band CPR with equal survival after out of hospital cardiac arrest. The randomized CIRC trial. Resuscitation. 2014 Mar 15 [Epub ahead of print]
    2. Perkins GD et al (2010) Prehospital randomised assessment of a mechanical compression device in cardiac arrest (PaRAMeDIC) trial protocol.Scand J Trauma Resusc Emerg Med. 2010 Nov 5;18:58

    • Thomas D says:

      Thanks for commenting! Good point on the unknown quality of manual compressions. On the other hand, they’re comparing MCD to the real world. This is as good as manual compressions are in the real world (in the places where the studies were done, anyway).

      But I’ve also experienced first hand how compression quality differs. Especially when you have EtCO2 and an art.line in. You can easily see them changing with different compressors, and also improve on non-optimal compressors by coaching them according to EtCO2 and ABP.

      On transporting OHCA patients, I think paramedic safety needs to be put higher on the list. A paramedic shouldn’t have to be standing unsecured in a blue lights racing ambulance to do compressions on a patient that has minimal chances of survival. A MCD can do that. Or the CA needs to be called on-scene. But that can be hard in certain situations – in emergencies, we all want to go that extra mile.

      On compression quality, the number of patients transported in CA is very low in real life, and also in recent studies, so I don’t think the difference between manual and mechanical compressions during transport will show up in the results. In a subgroup analysis, maybe, but numbers will be too small. Unfortunately, I haven’t had access to the CIRC trial yet, but looking forward to reading it in full.

  4. @Ermedic53 says:

    Hello all,
    A couple of questions for all in regards to these studies:
    1. For the resuscitation that were in the study, what was the size of the team used? Is a 2-4 person team as effective at chest compressions over time as the mechanical device? (If quality of CPR degrades in 1-2mins, how much rest is needed to return to optimal performance? Does provider age affect this time?)
    2. Is it possible this data suffers from study bias? (In best possible case manual CPR = mechanical, in actual practice could mechanical be better than manual CPR?)
    I work as a paramedic in a rural area of the U.S. where I am typically the sole advanced provider present. All the studies regarding mechanical CPR I have seen have been conducted in urban areas where it is likely a large number of people are available for the resuscitation. I can’t recall seeing in the studies a mention of the size of the team used. I wonder if there is a decline in quality of CPR as the number of rounds of CPR the rescuer provides increases. (Is 1 round every 4 mins as effective as 1 round every 8-10 mins per rescuer?)

    • Thomas D says:

      Thanks for your comments! It’s great to have input from various settings, as many of our interventions need to be adapted to the local settings. Like you point out, when you’re really low on hands, MCDs might help (but see above comments for contrary views). Still, the role to assume for an advanced paramedic might be to oversee the resus, leading and instructing, making sure the others do adequate CPR (if there are enough ‘others’). Or what are your thoughts?

      I think the limit is between 2 and 3. I don’t think 2 people are enough to run an effective code, but 3 is good and 4 is perfect, I think. The team size isn’t mentioned, but my experience in urban OHCA is that you’ve mostly got more hands than you need!

      I think the studies might well suffer from bias, again, the above comments go into that perfectly. Although they also argue that manual CPR might be suboptimal in the control group as opposed to ‘too good’ compared to real life. As compression quality isn’t measured in any way – we don’t know. But it seems to be that measuring CPR quality will be very hard to do for an OHCA study. So we will probably never know. Very interesting thoughts and necessary critisism for the debate, though!

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