In the Classroom edited by
Teaching with Problems and Case Studies
Grant R. Krow Temple University Philadelphia, PA 19122
Kim Kostka University of Wisconsin–Rock County Janesville, WI 53546
Using Clinical Cases To Teach General Chemistry
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Brahmadeo Dewprashad* and Charles Kosky Department of Science, Borough of Manhattan Community College, CUNY, New York, NY 10007-1097; *
[email protected] Geraldine S. Vaz Department of Family Medicine, Jamaica Hospital Medical Center, 8900 Van Wyck Expressway, Jamaica, NY 11418 Charlotte L. Martin Queens Bridge to Medicine, Sophie Davis School of Biomedical Education, CUNY, Jamaica, NY 11451
General chemistry has a profound bearing on studies of health and medicine. However, the relationship is very subtle and not often appreciated by premedical and allied health undergraduate students. In addition, many of the current textbooks (1–6) do not focus on the relationship between chemistry and medicine. We sought to make the connection more obvious to enrich the classroom experience and better motivate students. A clinical case study was designed and used to show that, in a typical clinical scenario, many chemical principles are involved and that an integrated knowledge of chemistry and biology is essential to the understanding, diagnosing, and treating of illnesses. It was felt that such a case study would be a positive learning experience for students as well as an effective method to promote active learning (7–11). Clinic Case The case involves an elderly patient who was brought to the emergency room. The results of his physical examination and laboratory analysis of his blood are given. The case is presented in a format similar to that used clinically and suitable explanations are included to make it comprehensible to nonmedical persons. The students work through the chemical principles involved in the doctor’s diagnosis and treatment options for the patient. The problems are presented under these headings: 1. Application of conversion factors to principles involved in determining possibility of infection, any weightrelated risks, and dosage of medication for infection 2. Application of pH, pKa, buffering, Le Châtelier’s principle, moles, molarity, and percentage concentration to blood chemistry 3. Application of pH, osmolarity, and osmotic pressure to principles involved in rehydration of the patient 4. Application of radioactive decay in understanding the principles of imaging 5. Application of mole fraction, partial pressures, kinetics, and Le Châtelier’s principle in principles of respiration 6. Application of solubility product and common-ion effect in diagnosis of stomach ulcers
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7. Application of stoichiometry, neutralization, and common-ion effect in treatment of excess acid production
The complete case study, with accompanying questions and solutions, is provided in the Supplemental Material.W Procedure The clinical case was assigned to students at the end of a two-semester course in general chemistry in the Queens Bridge to Medicine Program of the Sophie Davis School of Biomedical Studies. Students were placed in peer-led groups of six, and each group was asked to discuss the clinical case and provide solutions to the accompanying questions during two, two-hour sessions. Students were provided with textbooks in general chemistry, anatomy and physiology, medicine, and pharmacology (1–6, 12, 13). In addition, the instructors provided guidance to each group. The problemsolving sessions were followed by a two-hour discussion in the next class session where each group presented their solutions to a portion of the questions pertaining to the case. Group instructions and instructors’ observations are provided in the Supplemental Materials.W Discussion The discussions were very lively and afforded the instructors the opportunity to revisit and reinforce most of the basic concepts in general chemistry. It was very heartening to see that, after the discussion period, many students had additional questions pertaining to health and chemistry. The clinical case also generated many office visits from students who shared their own or relatives’ medical experiences with questions pertaining to the relevant chemical principles. This provided the instructors with additional opportunities to review and integrate previously taught fundamental chemical concepts. However, great pains were taken to emphasize to students that the diagnosis and treatment of diseases requires an integrated application of principles from many disciplines, and that proficiency in general chemistry is but one of the first of many steps towards a career in healthcare.
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Journal of Chemical Education
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In the Classroom
Evaluation
since as all of the pertinent medical information is presented in nonmedical language in the case.
An anonymous survey was done in order to elicit students’ perception of the exercise. Students’ responses were very favorable. One of the questions asked was whether an understanding of general chemistry is necessary for the treatment and care of patients; the students were unanimous in their agreement that it was. Until the case study, we had difficulty conveying this point to these students. In fact, most of the students indicated that they were surprised as to the extent of the application of chemical principles to medicine. Details of the evaluation and students’ responses are available in the Supplemental Materials.W Conclusion We have found this approach to teaching and reviewing general chemistry to be very effective. Almost all of the students showed greater enthusiasm and a higher level of participation than usual during the case study. While this case study does not cover every concept in general chemistry, it does highlight and reinforce many of the important concepts. This case study can be handed out at the beginning of a course in general chemistry, and at intermittent steps throughout the course, relevant problems can be solved as the appropriate topics are covered. We expect that this approach would motivate students at the beginning of the course. Alternatively, the case study could be used at the end of the course as a review as we did in the Queens Bridge to Medicine program. Also, the case can be used in live or e-tutoring sessions as it has a range of problems requiring varying levels of skill. Furthermore solutions are provided to the questions. The nonavailability of the cited medical reference books (12, 13) would not preclude educators from using the case study,
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Supplemental Material
The case study, its accompanying problems and solutions, group instructions, instructors’ observations of group activities, and the results of the student evaluation are available in this issue of JCE Online. Literature Cited 1. Hill, J. W.; Petrucci, R. H. General Chemistry, An Integrated Approach, 3rd ed.; Prentice Hall: Upper Saddle River, NJ, 2002. 2. Zumdahl, S. S.; Zumdahl, S. A. Chemistry, 6th ed.; Houghton Mifflin Company: Boston, MA, 2003. 3. Brown, T. L.; LeMay, H. E. Chemistry, The Central Science, 8th ed.; Prentice Hall: Upper Saddle River, NJ, 2000. 4. Petrucci, R. H.; Harwood, W. S.; Herring, F. G. General Chemistry, 8th ed.; Prentice Hall: Upper Saddle River, NJ, 2002. 5. Oxtoby, D. W.; Freeman, W. A.; Block, T. F.; Chemistry, Science of Change, 4th ed.; Brooks/Cole: Pacific Grove, CA, 2003. 6. Moore, J. W.; Stanitski, C. L.; Jurs, P. C. Chemistry, The Molecular Science; Brooks/Cole: Pacific Grove, CA, 2002. 7. Duprey, R.; Sell, C. S.; Lowe, N. D. J. Chem. Educ. 2003, 80, 513. 8. Zeile, J. W.; Jones, L. J. J. Chem. Educ. 2001, 78, 1170. 9. Bennet, N.; Cornely, K. J. Chem. Educ. 2001, 78, 759. 10. Krow, G. R.; Krow, J. B. J. Chem. Educ. 1998, 75, 1583. 11. Cornely, K. J. J. Chem. Educ. 1998, 75, 475. 12. Wyngaarden, J. B. Cecil Textbook of Medicine, 19th ed.; W. B. Saunders Company: Philadelphia, PA, 1992; p 519. 13. Marieb, E. N. Human Anatomy and Physiology, 3rd ed.; Benjamin Cummings: Redwood City, CA, 1995; p 768.
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