Fox J, Fiechter R, Gerstl P, et. al. Mechanical versus manual chest compression CPR under ground ambulance transport conditions. Acute Card Care. 2013;15(1):1–6.
This study examines the quality of CPR performed by either a paramedic or the LUCAS mechanical CPR device. The researchers had a driver cover a predesignated course in the city with typical changes in direction, railway crossings and speeds up to 78 mph.
In the back was a Laerdal MegaCode manikin using Laerdal Skillmaster software that recorded the number and frequency of chest compressions and classified them as deep (sternum compression >5 cm), moderate (4–5 cm) or soft (<4 cm). Time intervals with no compression were also recorded.
Six teams of paramedics performed CPR during the transport, changing positions every two minutes or approximately 200 compressions. Their performance was compared to that delivered by the LUCAS device over the same course and conditions. The study called only for compressions as the manikin was hooked to a ventilator, and no defibrillations or medications were delivered.
There was no statistical difference in compression rate between manual and mechanical CPR, though manual CPR rates varied between 91 and 112/min. For manual compression, only 67% were at the recommended depth (>5 cm). Amazingly, the hands-off time only ranged between 0–7 seconds.
Keith Wesley’s Comments
Many may be asking why I reviewed a study with such obvious results. It’s no surprise a machine can perform CPR more efficiently and effectively. Past studies indicate manual CPR in a moving ambulance results in less than 25% of cerebral and coronary blood flow compared to stationary CPR. Humans push too fast and/or not hard enough.
Performing chest compressions is fatiguing and the back of an ambulance rolling lights and sirens through the night is downright dangerous. So dangerous, in fact, I consider it bordering on employer negligence if condoned or even sanctioned. When you combine the poor outcome of these cardiac arrest victims receiving worthless CPR while exposing the responders to career- or life-ending injuries, I simply wonder who is reading the science at all. If this information was well-known and accepted, then every ambulance in America would be equipped with a mechanical CPR device. So why aren’t they?
I don’t buy the argument that they’re too expensive. Every service, large or small, somehow finds the funds to purchase and maintain a $150,000 ambulance on a 10-year replacement plan. Fire service apparatus is state-of-the-art and contains extrication tools that are utilized no more often than a mechanical CPR device would be. Perhaps these devices just aren’t sexy enough. Perhaps the idea of replacing a human being with a machine to save a life is unsettling.
But the science doesn’t lie. If we’re going to save more victims of cardiac arrest, we have to overcome all obstacles and embrace the value—and effectiveness—of technology.
Karen Wesley’s Comments
I know, right? The choice should be obvious. The device provides the muscle, and the human provides the brainpower. The study has two rescuers in the ambulance—the truer comparison would be one rescuer providing compressions the entire transport. This is much closer to what many services face.
In teaching CPR, I often find providers fatigued after the two minutes of one-person CPR. This is in a classroom with no other activity required of them. Add assessment and movement of a patient from scene to ambulance, and you’re already behind the eight ball on exertion. Ideally a mechanical CPR device would take over from point of movement to the transporting vehicle, allowing the oxygen demand of the caregiver to
be used on critical thinking rather than physical requirements.
When we talk about expense, you’re correct again Doc. So many other items less frequently used with higher prices often fill the shelves. But when it comes to the safety of our providers and optimal care for our patients, it really doesn’t take much to realize that chrome handles or fancy graphics aren’t where we need to put our budget monies.
So, should mechanical CPR devices become standard? Definitely! Get those pancakes flipped and the chicken roasted—whatever it takes for funding a device that may save your life, as a rescuer or as a patient.