Americans are increasingly relying on hospital emergency rooms to treat all manner of injuries, even minor ones. That places a high priority on decision models about which problems need emergent care, including expensive imaging studies. There are many clinical decision rules to stratify patients in terms of risk, but some of the most important are the Canadian Head CT Rule and the New Orleans Criteria.

Both are intended to reduce radiation exposure — and expense — from the frequent use of CT scans. Each of the systems utilizes a list of criteria, such as age, mental status after injury, vomiting and nausea, and amnesia. They vary slightly, with the Canadian rule using age 65 as the bottom age, while the New Orleans criteria uses the age of 60. The New Orleans criteria states that post-trauma headaches are a sufficient basis for ordering a CT while the Canadian system does not include that clinical indication.

Chest pain — perhaps the most common and most risky of presenting symptoms — is the focus of a scoring system called the HEART score, which stratifies patients according to history, EKG, age, risk factors for heart attacks, and the results of a troponin blood test. If patients have three or fewer of the enumerated risk factors, they have a 0.9-1.7% risk of a negative cardiac outcome in 30 days. Some studies show that this scoring system is as good or better than a stress test in establishing such risks.

None of the scoring systems for ER patients provide a “standard of care” in and of themselves, but they can be very useful for attorneys who are deciding whether a case has merit. Even if not admissible as establishing the standard of care, they also provide an excellent checklist that can be used by claimants’ attorneys in deposing doctors about their ER decision-making.