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Eric J. Herrera
Department of Chemistry
California State University, Sacramento
Diabetes and Acid/Base Chemistry: A Case of Diabetic Ketoacidosis (DKA)

This case study focuses on a teenage patient with type 1 diabetes mellitus (T1DM) who presents with severe acidosis, becomes combative and loses consciousness, and is subsequently treated and released. The scenario is used to teach the topics of metabolic hormones, cellular respiration, fat and carbohydrate metabolism, clinical analysis, and treatment. The case incorporates chemistry concepts related to ketone bodies, acid/base chemistry, blood buffer equilibrium, and Le Chatelier's principle in a setting that is pertinent to nursing and health care students. The level of difficulty is appropriate for beginning chemistry students and could be used in secondary or college classrooms. The case includes ample clinical measurements and vitals for performing calculations, which can also be used for graphing exercises. Higher-order topics that could be explored upon completion of the case to assess student understanding include vomiting during acidosis, acidosis related to exercise (lactic acidosis), respiratory acidosis (COPD and pneumonia), and acidosis related to alcoholism.

Properties of Gases: A Case Study of the Bends 

In 2012, Mike Prickett, a world-renowned underwater cinematographer, was working on a commercial photo shoot in Tahiti when he witnessed a fellow diver sinking and drowning. While saving the drowning victim, Mike fell victim to decompression sickness (the bends), which led to paralysis from the chest down. This interrupted case study uses Mike's story to explore the kinetic molecular theory of gases, gas laws (specifically Boyle's Law and Henry's Law), hyperbaric oxygen therapy, and partial pressures of gases in mixtures, including the human blood stream. Students investigate how SCUBA equipment works and use a sketching activity to visualize the pressure changes that affect divers as they travel underwater. In-class demonstrations are used to help students visualize the types of conditions that effect changes in gas behavior and to draw connections between them, theoretically and in real life. The case was originally designed for use in a lab setting for undergraduate introductory chemistry or General Organic and Biochemistry (GOB) course, or for an introductory level chemistry class for nursing students.