Six Questions With an Aortic Health Expert on Prehospital Care of Aortic Emergencies

Robert Ohle, MD, with Health Sciences North-Ontario, is on the Professional Advisory Board of the John Ritter Foundation for Aortic Health. The goal of this organization is to “raise awareness and change outcomes” for patients who are at risk of spontaneously bleeding out internally due to a flaw in their aorta. Ritter’s wife, Amy Yasbeck, founded the foundation following the actor's death from a misdiagnosed acute thoracic aortic dissection in 2003.

Ohle receives no salary for his role. One of the duties he enthusiastically performed in the pursuit of this mission was taking 20 minutes out of his busy day to answer my questions about prehospital aortic emergencies.

EMS World: What’s the difference between an aortic dissection and aneurysm?

Ohle: The aorta is our largest, highest-pressure artery and runs the entire length of the chest and abdomen. An aneurysm is a weakening in the wall of this vessel, which can balloon and rupture. Aortic aneurysms can also exist without doing any serious harm. An aortic dissection is a bad thing happening right now. It happens when a tear or weakening in the inner layer of the aorta “unzips” the vessel. At a prehospital level, it doesn’t really matter whether this giant hose of life is bursting or tearing. They’re both true, surgical emergencies.

EMS World: What exam or history findings should prompt prehospital providers to consider an aortic emergency as their patient’s chief complaint?
Ohle: It’s a challenge. Pulmonary Embolus and Acute Coronary Syndrome (ACS) are far more common than aortic emergencies; however, aortic emergencies are almost inevitably fatal.

These presentations should prompt consideration of an aortic complaint:

• Chest pain with neurologic symptoms
• Chest pain with a low blood pressure
• “Thunderclap” pain; that is, abrupt abdominal or chest pain that is maximal at onset
• A family history of aortic emergencies
• A family history of sudden death under the age of 60, especially in first degree family members
• A known structural flaw in their aorta (this may be found on a medical alert bracelet)
• A known connective tissue disorder such as Ehlers Danlos or Marfan, though there are many others

EMS World: Prehospital providers are taught that a significant difference in blood pressure, at least 15 mmHg, between arms is a sign of an aortic emergency. How true is this?

Ohle: This finding is specifically associated with dissection rather than aneurysm. In the right clinical context, this could suggest an aortic emergency. However, about 20% to 30% of the population will have this difference at baseline due to stiffened arteries. So, unfortunately this finding is probably meaningless most of the time.

EMS World: How common is the presence of a pulsating mass in the abdomen of a patient having an abdominal emergency?

Ohle: If you can actually feel it, it’s very helpful. But it’s not very common to feel it. Basically, if you can feel a pulsating mass in a patient’s abdomen this very challenging diagnosis becomes a slam dunk. Unfortunately, the absence of it is not a rule-out of any kind.

EMS World: What effect will giving oral aspirin to a patient suffering from an aortic emergency, believing that their chief complaint is actually Acute Coronary Syndrome instead, have on their outcome?

Ohle: Theoretically, giving aspirin to these patients seems like it would be ruinous. After all, they’re bleeding massively and aspirin does reduce a body’s ability to form a clot. ACS is dozens of times more common than aortic emergencies so aspirin for chest pain is generally indicated and reasonable. Surprisingly, while aspirin does increase their bleeding, there is actually no statistical evidence to indicate that it increases mortality in these cases. Keep administering aspirin when indicated.

EMS World: Will tranexamic acid be able to help a patient having an acute aortic emergency?

Ohle: There’s no evidence to say it will have a significant impact on patient outcomes, but it’s unlikely to cause any harm. Tranexamic acid has largely been shown to be beneficial specifically in traumatic bleeding. Whether or not to attempt to use it in this case is ultimately up to the discretion of a particular provider as the data suggests there is neither harm nor benefit.