A Cold Case: Myxedema Coma.

Abstract

Audience: This case was designed and developed to train emergency medicine residents through high-fidelity simulation and experiential learning in the management of a hemodynamically unstable patient presenting with myxedema coma.

Introduction: Myxedema coma refers to decompensated hypothyroidism manifesting as altered mental status and multisystem organ dysfunction. Myxedema coma is a life-threatening endocrine emergency that requires prompt recognition and treatment. Mortality associated with this condition is high, approaching 30% with optimized treatment, and nearly 100% if untreated.1 Whilst myxedema coma is a cannot-miss diagnosis, it is a relatively uncommon presentation to the emergency department (ED); incidence of myxedema coma is as low as 1.08 per million people per year.2 The clinical triad of myxedema coma is altered mental status, hypothermia and the presence of a precipitating factor.3 Typically, the patient will be over age 60 years, female, and with clinical features associated with hypothyroidism including dry skin, coarse hair, non-pitting edema.4 Myxedema coma has a temporal association with most cases occurring in the winter months.5 Despite knowledge of the disease process, recognition can be challenging, thus delaying treatment. Therefore, clinicians must have a high degree of suspicion to make the diagnosis in the ED. These characteristics of infrequency and lethality suggest medical simulation as an ideal medium to educate learners on recognition, diagnosis and management of myxedema coma in the ED in a realistic and safe setting.

Educational objectives: The primary educational goals are to elicit the differential diagnoses for a patient with altered mental status, order an appropriate workup, and initiate life-saving interventions for a patient with decompensated hypothyroidism. At the conclusion of the simulation, the learner is expected to: 1) Recognize the key features on history and examination of a patient presenting in myxedema coma and initiate the appropriate workup and treatment, 2) Describe clinical features and management for a patient with myxedema coma, 3) Develop a differential diagnosis for a critically ill patient with altered mental status, 4) Discuss the management of myxedema coma in the ED, including treatments, appropriate consultation, and disposition.

Educational methods: This case was delivered as a high-fidelity simulation employing a computerized manikin as the patient, and a confederate actor in the role of the registered nurse (RN). A post-scenario debriefing session was facilitated by the instructor as a four-step formative process described by Rudolph, et al.6 Other aspects of the debriefing included discussion about the pathophysiology, presentation, management, and disposition of patients with myxedema coma.

Research methods: Learners were asked to submit anonymous feedback immediately upon completion of the case. Objective data from learners was obtained ranging from 4th year medical students on their Emergency Medicine (EM) clerkship rotation at one clinical site to PGY1-4 EM residents from two residency programs, both experiencing the same simulation at the same site. The post-simulation survey was the same for all learners. Drop-down lists were used when asking the level of training and how many cases of myxedema the learner had seen. The rest of the learner feedback was assessed with a 5-point Likert scale (1: strongly disagree to 5: strongly agree). Anonymous open-ended comments were available for narrative feedback.

Results: Thirty-three learners completed the post-simulation surveys. Learners rated the effectiveness of the simulation very highly with an average score of 4.6/5 on the Likert scale. Most learners endorsed supporting the use of the case in their simulation curriculum (average of 4.5/5). Debriefing effectiveness was also rated very highly, (average 4.8/5). As noted, topics of discussion during debriefing included clinical features and pathophysiology of myxedema coma, principles of resuscitation, empiric management of decompensated hypothyroidism, and disposition.

Discussion: The simulation case was an effective and reproducible method of training EM residents in the recognition and management of a relatively rare yet fatal condition: myxedema coma. Learners were challenged to aggressively resuscitate an unstable critically ill patient whilst thinking through many potential diagnoses in a patient with altered mental status. After review of the learner feedback, the simulation and debriefing were regarded as effective and successful in achieving the learning objectives. The quality, accuracy and effectiveness of the educational content is clearly positive as indicated by the overwhelming positive responses. Furthermore, the survey results demonstrate that many residents (60.6%, Figure 1) have never seen a case. This supports the rarity of the condition and highlights the need for simulation to fill the learning gap.

Topics: Medical simulation, emergency medicine, myxedema coma, hypothyroidism, endocrine emergencies, altered mental status, hypoglycemia, hypothermia, bradyarrhythmia.