Acetaminophen Toxicity

This is a practice structured interview case which is appropriate for emergency medicine residents at all levels of training.

Acetaminophen (APAP) is an over-the-counter medication commonly used by adult and pediatric populations. While acetaminophen has demonstrated to be reasonably safe and well-tolerated at therapeutic doses, it can cause severe hepatic toxicity if taken in excess. Acetaminophen toxicity is the most common cause of acute hepatic failure in the United States, accounting for approximately 50 percent of all reported cases and 20 percent of liver transplants.1 In 2021, poison control received more than 80,000 cases involving acetaminophen-containing products, and acetaminophen toxicity is responsible for 56,000 - 75,000 emergency department visits annually.2,3 Acetaminophen toxicity is compounded by introduction of acetaminophen combination products, with unintentional and chronic overdose accounting for over 50 percent of cases of acetaminophen-related acute hepatic failure in the United States and United Kingdom.4 Given the prevalence of acetaminophen toxicity and oftentimes vague presentation of symptoms, it is imperative that emergency medicine physicians promptly identify and manage acetaminophen toxicity.

At the end of this practice oral board session, examinees will be able to: 1) demonstrate an ability to obtain a complete medical history in an oral boards structured interview format, 2) review appropriate laboratory tests and imaging to evaluate abdominal pain, 3) investigate a broad differential diagnosis for right upper quadrant abdominal pain, 4) recognize chronic acetaminophen toxicity, 5) initiate the appropriate treatment for chronic acetaminophen toxicity, 6) demonstrate effective communication with the patient, consultants, and the admitting team.

This is a structured interview case intended to evaluate learner thought processes throughout the evaluation, workup, and diagnosis of a patient with acetaminophen toxicity.

The practice structured interview case was developed and then tested in a small group environment with emergency medicine residents at different levels of training. After the case was completed, learners and instructors were given the opportunity to assess its strengths and weaknesses by providing electronic feedback during a residency conference. The format of oral boards' assessing the strengths and weaknesses of a case was mimicked through having one instructor to one to two residents per case administration. Subsequent modifications were made to remove ambiguity based on the feedback provided.

This case was administered as part of our residency oral boards didactics series. Thirty-one EM residents PGY1-PGY3 were administered in the case. Ten learners completed an evaluation form as part of the annual Program Evaluation Committee survey. When asked to evaluate the quality of the oral boards didactics series on a scale of 1 to 5, they rated it a 4.4 out of 5.

This practice structured interview case was an effective model to help prepare residents for their oral boards and to assess their understanding of identifying and treating acetaminophen toxicity. Based on learner and instructor feedback, several laboratory results were added to the stimulus package and clarifying language to the examiner script.

Oral boards, structured interview, abdominal pain, acetaminophen toxicity.