Impedance threshold device and active compression/decompression CPR on the Standing Orders podcast

I was recently a guest on the Standing Orders podcast discussing the Impedance Threshold Device (ITD) or ResQPOD and active compression/decompression CPR (ACD CPR) with the ResQPump.

Specifically, we reviewed the recent Lancet article:

Standard cardiopulmonary resuscitation versus active compression-decompression cardiopulmonary resuscitation with augmentation of negative intrathoracic pressure for out-of-hospital cardiac arrest: a randomised trial. Aufderheide, TP et al. (2011) Lancet 377(9762): 301-311.

You may recall that I had previously interviewed Keith Lurie, M.D. about the ResQPOD after the ROC PRIMED trial.

One of the more interesting things about the new trial from Lancet is the difference between the statement Tom Aufderheide M.D. made when the National Institute of Health announced that the ROC PRIMED trial was stopping enrollment:

“While the ITD is based on sound physiologic principle, in this study it did not appear to improve survival rates for adults in cardiac arrest outside the hospital.”

and this statement Tom Aufderheide M.D. made following the Lancet article (which appeared in a press release I received via email).

“The goal of resuscitation during cardiac arrest is long-term survival with preservation of brain function. This new, effective intervention achieves that goal and is potentially the most significant advancement in the treatment of cardiac arrest since defibrillation.”

Potentially the most significant advancement in the treatment of cardiac arrest since defibrillation!

How about that sports fans?

You can listen to this episode of the Standing Orders podcast here:

Episode 4: Making Sense of Confusion

Special thanks to Mr. Matt Fults, Dr. Chris Russi, and Mr. J.D. Graziano for inviting me on the show! I think I mentioned before that, in my opinion, the Standing Orders podcast is the best new medical podcast of 2011.

Be sure to check out the other great episodes!

You can also find the Standing Orders podcast on Facebook HERE and on Twitter HERE.

Incidentally, during the show I promised I’d ask Keith Lurie, M.D. why it’s not a good idea to hold a mask with an ITD over the patient’s face and perform continuous chest compressions without ventilations.

Here’s the answer:

“If you do not ventilate but perform CPR with the ITD in place, then air is pushed out of the lungs and not allowed to get back in. The lungs become atelectatic, probably faster than if there was not ITD in place (though never studied), and then it is harder to move blood through the lungs from the right heart to the left heart. Even without the ITD, the lungs will become atelectatic without positive pressure ventilations during CPR: this is a bad thing as pulmonary vascular resistance goes up and blood does not circulate. That is one of the reasons I stress the need to ventilate.”

Order recommended:

  • Standard Chest compressions right away
  • Apply ITD with 2-handed face mask technique – hold firm all the time (see figure)
  • Ventilate 30:2 until intubated

See also:

Interview with Keith Lurie, M.D. discussing the ResQPOD and the ROC PRIMED Trial


  • Timothy Clemans says:

    I meet with fire department officials yesterday for Bellevue, Washington (King County). I asked about the decline in survival rates in two communities in the county, 55% to 50% and 46% to 43% and all of the county 49% to 46% (Bystander-Witnessed VF). They didn’t know why the rates declined. I think it has to do with them using effective therapies durning the ROC trial.

    I think the ROC trial is incapable of concluding effective therapies are effective because most of the trial sites are low performing. shows that two of the ROC sites saved zero transported gun shot patients.

    We should ignore research involving low performing agencies. For example if DC & San Francisco were to publish research claiming the AHA 2005 guidelines don’t improve survival we should ignore that research because their bystander-witnessed VF survival rates are 10%. There was a randomized trial of the AHA 2005 guidelines showing no improvement. However, that agency has an average first arriving unit response time of 10%. I’m convinced AHA 2005 is effective because Suburban King County’s bystander-witnessed VF survival increased 11% and Kanas’ bystander witnessed VF survival rate increased 21%.

    Another problematic research study was the one of compression-only telephone CPR instructions. King County and Thurston County have >40% bystander-witnessed VF survival rates. However, London only has a 16% survival rate for bystander-witnessed VF. The City of Seattle’s randomized trial of compression only telephone CPR was positive.

  • Christopher says:

    I thought the biggest problem with the ROC PRIMED study was too many independent variables made it difficult to determine which, if any, intervention made a difference.

    My service has just placed these on the trucks for usage on arrests, but we only work ~15 a year so it will be difficult to notice any difference.

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