Common Tread

Ask the doc: What's an AED and is it something motorcyclists need?

Dec 05, 2018

Technology seems almost as infiltrative as an unchecked malignancy but is generally beneficial instead of harmful. Well, except for selfies in front of moving trains or perhaps for Pokemon Go!, where players are famous for not sustaining injury while walking into, or off of, things while playing.

Technology such as ABS systems or traction control for on-road motorcycles increases our safety. So can advancements in medical devices. In Britain, the family of a British motorcyclist who died in a crash has set up a foundation to buy defibrillators and install them in areas where it would take some time for emergency responders to arrive — which was the case in the British rider's death.

What is this technology and is it something motorcyclists need?

Medical technology has brought us increasingly miniaturized devices that can sense an abnormal heart rhythm and deliver a countershock that will hopefully restore a normal rhythm. People with heart disease can now have these devices implanted by a cardiologist in the catheterization lab instead of requiring a surgeon to insert the device in the operating room.

For the rest of us, the primary need for a defibrillator that can sense heart rhythm and deliver a countershock is cardiac arrest. Virtually everyone is familiar with the paddles that deliver a countershock after the device operator yells “clear!” so as not to shock anyone else who is helping and touching the patient. That early device required the operator to correctly interpret the rhythm and select the correct amount of energy to deliver. Technological miniaturization, battery durability, enhanced computer processing and decision-analysis capability have removed the operator from the decision-making. Modern devices in and out of the hospital now have patches that may be applied to an individual’s chest that connect to an automated device; they are termed Automated External Defibrillators, or AEDs for short.

AED kit
An AED kit. Zoll photo.

These small and portable battery-driven devices sense the patient’s heart rhythm and will deliver an appropriate countershock if there is a rhythm for which a shock should be delivered and if a countershock has the potential to restore a survivable rhythm. These are the devices the foundation in Britain is raising funds to buy because of a motorcyclist's death. That raises the question: "Is this something we as riders need?”

To answer that question, we need to understand why people die after motorcycling crashes and whether any of those conditions are likely to respond to defibrillation. In general, since most motorcycle crashes are solo, deaths are related to brain injury, spinal cord injury, aortic rupture, or solid organ injury with massive bleeding. None of these are responsive to defibrillation, as they are driven by damage to the central nervous system or massive hemorrhage.

Do people crash after having a heart attack? Sure they do, but just not in great numbers. We do know about drivers of cars who have heart attacks. That event occurs in only limited frequency. Current estimates place car crashes related to driver heart attack at about 11 percent of all fatal wrecks. The best data is from Finland, where speeding was an infrequently related factor, so maybe this data does not apply so much to the United States, where highways are often mistaken for racetracks.

How about motorcycle crashes involving other vehicles? These events are marked by death from the same kinds of things as in single-motorcycle crashes, but often with even greater transmitted forces from two vehicles as they bring their separate energy together to a violent and abrupt end. This process is termed deceleration injury and it tears organs and blood vessels apart, leading to massive bleeding. And it is devastating. These injuries are not responsive to defibrillation. Instead, bleeding control is needed and so EMS is better off not spending time at the scene of such crashes in favor of rapid transport to a trauma center.

So where might an AED truly be helpful? It might be superb for a low-speed crash where a heart attack is the cause and is not accompanied by major injury and bleeding. An AED in that circumstance may be truly lifesaving.

Of course, if you want to position an AED where you are likely to find motorcyclists at risk of a heart attack, many sites come to mind, including those detailed in Lemmy’s “Brap Brap, Nom Nom” series…