Without evidence of benefit, an intervention should not be presumed to be beneficial or safe.

- Rogue Medic

In Defense of No Improvement by Medic Madness – Part IV

ResearchBlogging.org
 

Continuing from Part I, Part II, and Part III in response to what I wrote about the failure of the LUCAS,[1] Sean continues with –
 

Another issue I have with this data, is that it doesn’t address the following variables:

  • Down time
  • Whether or not bystander CPR was performed
  • Medications used
  • Whether or not an advanced airway was placed
  • Length of resuscitation

All of these things are important when looking at the effectiveness of the LUCAS. Had all of these cases been witnessed full-arrests with immediate intervention, then I might feel differently. Perhaps they did look at these things, but from the data that’s available to the general public, I can’t determine whether or not the LUCAS doesn’t “do any good”. From what we can see, at the very worst it keeps up with some of the best-trained responders out there. Not bad, if you ask me.[2]

 

Did you look at the paper?

Are you guessing at what the study shows based on intuition?

The information is there. This will be mostly a picture book response.

Down time?

Whether bystander CPR was performed?
 


Click on images to make them larger.[3]
 

Medications used?
 


Study design.[4]
 

In both groups, ventilation and drugs were given according to guidelines.16 [3]

 

There is no breakdown for medications.

Of course, medications have not been demonstrated to improve any outcome that matters.

The best way to determine this would be by –

Length of resuscitation or time to ROSC (Return Of Spontaneous Circulation).?
 


 

Whether an advanced airway was placed?
 


 

This may favor the LUCAS, since airways seem to interfere with survival.

Maybe manual compressions really are not the same during an intubation attempt. Maybe people back off on compressions. Therefore, maybe it is easier to intubate under those circumstances. We do not know. The LUCAS may make intubation more difficult.

Worse CPR may mean better intubation, but since intubation doesn’t improve anything, is that a good compromise?

Which is our no improvement device of choice? 😳
 

Conclusion

We need to be looking at the whole picture here. If we can design a machine to do textbook-perfect CPR, and it doesn’t produce textbook results, then maybe we need to re-evaluate our textbook. Even if the studies do prove that the device isn’t improving survival rates, we still can’t discard the device as “worthless”. It has its place in situations with limited responders. And yes, the data supports that.[2]

 

Why assume that a textbook is right?

How often do I cite any textbook? The only textbook I regularly (and usually negatively) cite is ACLS.

Textbooks tend to be the last to change, but textbooks do change. The change is because research demonstrates that the textbook is wrong and needs to be revised. Textbooks are expected to be revised as we learn more from research.

When you suggest that the research does not confirm the biases of the textbook writers as evidence of a problem with the research, there is the possibility that you are right. This research may be providing evidence that the assumptions of the textbook writers are wrong. The way we find out is by looking closely at the quality of the research and looking at similar research.

However, LINC is good research.
 

Experimental studies with the mechanical chest compression device used in this study have shown improved organ perfusion pressures, enhanced cerebral blood flow, and higher end-tidal CO2 compared with manual CPR, with the latter also supported by clinical data.9- 11 [3]

 

Why is it that improving these surrogate endpoints does not improve what matters – survival? What do we not understand?

We should be more interested in doing no harm.

We seem to be more interested in throwing the kitchen sink at the patient, because what if the arrest is due to a kitchen sink deficiency?
 

Dr. Brooks Walsh also explains the failure of the LUCAS in this study in “We had a LUCAS save!” – No, you didn’t.

Peter Canning describes the failures of judgment in advocating for the LUCAS in Whup Kits and Chihuahuas.

Footnotes:

[1] The Failure of LUCAS to Improve Outcomes in the LINC Trial
Wed, 05 Mar 2014
Rogue Medic
Article

The LUCAS, Research, and Wishful Thinking
Fri, 07 Mar 2014
Rogue Medic
Article

[2] In Defense of the LUCAS
March 12, 2014
by Sean Eddy
Medic Madness
Article

[3] Mechanical chest compressions and simultaneous defibrillation vs conventional cardiopulmonary resuscitation in out-of-hospital cardiac arrest: the LINC randomized trial.
Rubertsson S, Lindgren E, Smekal D, Östlund O, Silfverstolpe J, Lichtveld RA, Boomars R, Ahlstedt B, Skoog G, Kastberg R, Halliwell D, Box M, Herlitz J, Karlsten R.
JAMA. 2014 Jan 1;311(1):53-61. doi: 10.1001/jama.2013.282538.
PMID: 24240611 [PubMed – indexed for MEDLINE]

Free Full Text in PDF Download format from PEHSC.org.

[4] The study protocol for the LINC (LUCAS in cardiac arrest) study: a study comparing conventional adult out-of-hospital cardiopulmonary resuscitation with a concept with mechanical chest compressions and simultaneous defibrillation.
Rubertsson S, Silfverstolpe J, Rehn L, Nyman T, Lichtveld R, Boomars R, Bruins W, Ahlstedt B, Puggioli H, Lindgren E, Smekal D, Skoog G, Kastberg R, Lindblad A, Halliwell D, Box M, Arnwald F, Hardig BM, Chamberlain D, Herlitz J, Karlsten R.
Scand J Trauma Resusc Emerg Med. 2013 Jan 25;21:5. doi: 10.1186/1757-7241-21-5.
PMID: 23351178 [PubMed – indexed for MEDLINE]

Free Full Text from PubMed Central.

Rubertsson S, Lindgren E, Smekal D, Östlund O, Silfverstolpe J, Lichtveld RA, Boomars R, Ahlstedt B, Skoog G, Kastberg R, Halliwell D, Box M, Herlitz J, & Karlsten R (2014). Mechanical chest compressions and simultaneous defibrillation vs conventional cardiopulmonary resuscitation in out-of-hospital cardiac arrest: the LINC randomized trial. JAMA : the journal of the American Medical Association, 311 (1), 53-61 PMID: 24240611

Rubertsson S, Silfverstolpe J, Rehn L, Nyman T, Lichtveld R, Boomars R, Bruins W, Ahlstedt B, Puggioli H, Lindgren E, Smekal D, Skoog G, Kastberg R, Lindblad A, Halliwell D, Box M, Arnwald F, Hardig BM, Chamberlain D, Herlitz J, & Karlsten R (2013). The study protocol for the LINC (LUCAS in cardiac arrest) study: a study comparing conventional adult out-of-hospital cardiopulmonary resuscitation with a concept with mechanical chest compressions and simultaneous defibrillation. Scandinavian journal of trauma, resuscitation and emergency medicine, 21 PMID: 23351178
.

Comments

  1. My service is considering getting a LUCAS device, though not quite for the usual reasons. The interest is based on:

    1) Some of our at-home arrests occur in bedrooms which are extremely small/cramped such as trailers, where there’s unlikely to be side access from which to perform on the floor. In those cases, getting somebody onto a backboard and LUCAS device would be substantially faster, easier and safer than attempting to move the patient to a location in which CPR can be performed effectively. One case had us putting a Reeves under the pt. on the bed and performing CPR on the bed itself. This was not easy.

    2) Once we’ve done a few ALS rounds of CPR and we’ve decided that there is no hope for the pt., sometimes we’ll transport to the hospital. A LUCAS device allows us to transport much more safely. Note that we’re doing this mostly for the emotional well-being of the family, rather than of the patient, who’s effectively dead at that point.

  2. Forgive me if you have covered this point already and I have missed it.

    I’ve not seen in the studies cited any reference to or consideration of the time taken to deploy this device in practical circumstances.

    My [perhaps ill-informed] concern being that it needs 2 short-ish breaks or one longer break in compressions to pass the strap under and then mount the device.

    My bitter twisted cyniical mind experience tells me that it might not be put on in the right anatomical positon initially and need yet another break to re-position it.

    Not to mention “Shiny New Toy Syndrome” that affects a very small minority of people who devote all their attention to fiddling and faffing about with the “Shiny New Toy” rather than concetrating on the patient. Oh, I mentioned it!

    PS. If I have got this completely wrong then please feel free to call me a ‘buffoon’.

Trackbacks

Speak Your Mind