The sudden medical emergency doctrine as a defense to liability

In Pennsylvania, if you get sued for negligence (for example, if you are driving a car and hit someone), two potential arguments against liability are the sudden emergency doctrine, and the sudden medical emergency doctrine. In a recent decision, the Pennsylvania Superior Court clarified the difference between these two defenses while reversing the trial court's decision that found in favor of the defendant.

In Shiner v. Ralston, Mr. Ralston was driving a pickup truck for his employer.  The accident occurred when he drove across two rumble strips and a grassy median before hitting Mr. Shiners' car head-on.  Mr. Ralston was pronounced dead following the accident. An autopsy concluded that he had lost consciousness while driving due to a cardiac dysrhythmia.

After the Shiners filed suit, the trial court granted summary judgment in favor of the defendants, Mr. Ralston's estate and his employe.  It concluded that because the accident was the result of a sudden and unforseeable medical emergency, the defendants could not be held liable under the sudden emergency doctrine.

The Superior Court found that the trial court had erred by conflating the sudden emergency doctrine and the sudden medical emergency doctrine. 

The sudden emergency doctrine is a standard of conduct, and applies when a person who is driving prudently has little or no time to see and react to an emergency - for example, someone running into the street from behind a car that is parked at the side of the road.. 

The sudden medical emergency doctrine is an affirmative defense that may apply when there is a sudden loss of consciousness or the defendant suddenly becomes incapacitated.

The Superior Court held that for the purpose of summary judgment, the defendants had the burden of establishing that no reasonable jury could find that Mr. Ralston was negligent.  It concluded that neither the lack of any mention of cardiac symptoms in Mr. Ralston's medical records nor the testimony of his family that he had never previously had heart problems was enough to support summary judgment.  Further, the Shiners had presented a medical report that concluded that Mr. Ralston had sufficient time to respond to his symptoms and avoid the accident.

The take away lesson is that, while the sudden medical emergency doctrine is a viable defense, for the purpose of summary judgment (winning a case without a trial), the defendant  cannot simply rely on an absence of medical records documenting a preexisting a condition.  Accordingly, it must conduct an exhaustive investigation for any evidence from any source that reinforces its argument that the defendant's loss of consciousness was not forseeable.