The similarities between a CPR device, and a plunger
By Art Hsieh
|Editor's note: This column is in response to a recent story, "Minn. study: New device beats normal CPR in trial." Editorial advisor Art Hsieh talks about why this study makes theoretical sense.|
This announcement comes on the heels of the American Heart Association Resuscitation Symposium recently held in Chicago, where this study was first formally introduced. It certainly makes theoretical sense: Being bale to pull up on the chest during the decompression cycle creates even greater negative pressure inside the chest cavity, driving even more blood into the coronary arteries.
It also can promote full recoil of the chest. The ancillary device referred to by the article was an impedance threshold device, designed to help maintain negative pressure in the chest while compressions were being provided.
In the mid-90s a similar device was being evaluated in the department I was working in; it was shaped like a short plunger with a round handle on top. It was difficult to use; the handle wobbled if you didn't push down correctly, and it often left a huge welt on the patient's chest wall.
Perhaps more importantly, to really use it correctly you had to pull up on the handle, just like a toilet plunger. It definitely resulted in a more tiring experience in providing compressions; many times the rescuer would end up using the device as a rest, and actually keep weight on the chest wall during the recoil phase.
Coupled with the slower rate of 80 bets per minute, any potential improvement in outcome was probably blunted by these issues.
This points out how sometimes controlled studies can produce positive outcomes, yet that gets lost when introduced to the masses. Training and experience on any of these devices is critical to its success. Having not yet seen this particular device, I would be very interested in how it overcomes the issues with the 90s version. If it works, great! Let's get on it...but let's make we're ready and prepared to use it well.