A reader asked me to comment on the AutoPulse, the automated CPR device that straps around a patient's chest and delievers compressions at a consistent rate and depth.
Let me start by saying I have never used the device. I have talked to many medics who have and who have been amazed at the machine's abilty to provide excellent compressions to the point you can feel a pounding pulse, and who report more than expected return of spontaneous circulations.
While the Autopulse was initially hailed as a miracle device, it performed so badly in a recent multisite randomized study that the study was halted.(1) While very successful at gaining return of spontaneous circulation, it proved less successful than human CPR in the key category of having patients walk out of the hospital alive. (Some services are now removing the $15,000 device from their ambulances.)
In talking with medics who have used the device and in reading the studies, many of us feel that the drawback to the Autopulse may not be the machine, but the time it takes to get it on. The few people who have a chance of being saved to the point of walking out of the hospital alive have a very short window to be saved. If the thirty seconds to two minutes it takes to get the machine on and working properly delays excellent CPR in those critical early moments, maybe that is the difference.
Again, not having used it, I am not really qualified to make a judgement.
In the end I have to defer to the science. There are more studies of the autopulse going on, including a small recent study that showed positive results (2). However, an initial read of the study shows that human CPR was done for quite awhile initially and there was some selection bias in who eventually got the machine and who didn't. I am not the best at reading studies, but I have learned that you really need to dig into the study to determine its worth. Another thing to consider is who is funding the study and what relationship do the authors have to the subject being studied. In some cases, the author is the inventor of the device or is a consultant. They are trying to declare all conflicts, but sometimes it can be deceptive. An author presenting on the topic may declare he has no conflicts, but not reveal conflicts that coauthor have.
I recently read a study comparing two types of cervical spinal clearance, the Nexus criteria versus the Canadian c-spine rule. The study concluded the Canadian c-spine rule was better. Who did the study? The same people who developed the Canadian rule, and the trial was held in the area where all the doctors had been trained in the Canadian rule. This is not to say they are not right, just that you need to consider possible bias.
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At the regional council we often have vendors come in and give a presentation on an emergency product. I try to study up on the issue before the meeting so I can ask intelligent questions. We recently had a presentation on the Easy-IO. The company sent a salesman and a clinical specialist. The clinical person was awesome. She did a great job describing the product, answering questions and being frank about pros and cons. I was impressed. I have seen other demonstrations on products I actually like and been turned off by the claims that rely on anecdote and which stretch the science. I think too often in EMS, we fall victim to the next best thing -- Amiodarone, the AutoPulse...and then the science comes out and shows if we are not doing more harm than good, we are just spending a lot of money for unproven results. We always want to give our best to the patients, but it makes us susceptible to sales pitches. Unfortunately, budgets in EMS are tight, and we need to watch where our dollars go.
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(1) Manual chest compression vs use of an automated chest compression device during resuscitation following out-of-hospital cardiac arrest: a randomized trial.
(2) Out-of-hospital cardiopulmonary resuscitation with the AutoPulsetrade mark system: A prospective observational study with a new load-distributing band chest compression device.
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In response to a comment below on amiodarone, I have added a couple links that further discuss the issue of new drugs/devices and research.
Ludwig: Put a Gun to My Head
What's Missing From EMS Research
Discussion of Amiodarone/Lidocaine
The bottom line on the amiodarone issue was three fold 1) despite massive initial publicity about the study (Amiodarone saves lives!), the results showed no improvement in hospital discharge 2) it turned out the study was paid for by the manufacturer 3) the drug is much more expensive than lidocaine.
On a personal note, I have had positive experiences with amiodarone, but realize anecdote does not trump science.
