M. P. MCRAE
to be beneficial to their learning and appreciation of anatomy
and physiology.
The purpose of this paper is to describe an instructional ap-
proach to using clinical case studies in a first trimester human
biochemistr y course.
The Case Study Method
Students in a first trimester biochemistry course in a chiro-
practic doctoral program were presented with four clinical cases.
Each case focused on a specific topic in biochemistry (protein,
carbohydrate, lipid and nucleic acid metabolism). For each case
a full class period (50 minutes) was used to introduce the case
and 2 additional class periods were used to discuss the directed
question learning issues. The information that was freely avail-
able at the beginning of the first session included: age, gender,
race, appearance, and chief complaint. Details needed to diag-
nose the patient had to be generated through history taking,
physical examination and diagnostic tests. Each clinical case
study was presented in a simulated doctor patient scenario
where the instructor played the role of the patient. In this sce-
nario the students first took a history, followed by a discussion
and listing of the patient’s differential diagnosis. This was fol-
lowed by the physical examination and diagnostic tests. After-
wards the differential diagnoses were addressed and the listed
conditions were ruled-in or ruled-out. Ultimately at the conclu-
sion of this exercise the patient’s diagnosis was revealed, be-
cause “searching” for the patient’s diagnosis was not the goal of
this exercise.
The real goal was the mechanistic description of the encoun-
tered signs and symptoms of the disease as related to the bio-
chemical concepts covered in lecture up to that week. At the
conclusion of the first session the students were presented with
2 to 3 directed questions which are referred to as “learning
issues”. The learning issues were of sufficient depth without
requiring excessive amounts of time or effort by the students,
and therefore the students were assigned typically one week to
complete the learning issues. The learning issues were chosen
by the instructor with the purpose of directing the students to
explore in more detail the specific issues in biochemistry as
they related to the previous weeks lectures.
With one or two of the learning issues the students were
asked to formulate a specific me chanism for a particular sign or
symptom. To answer the question, the students were asked to
formulate the molecular steps involved in the mechanism and
arrange them in a proper sequence which explained the phe-
nomena of the case in terms of underlying disease mechanisms.
This activity develops the student’s analytic outlook to the
problem instead of merely reinforcing his or her talent for fact
recall. This task also sometimes required students to associate
the mechanism of one event with the mechanisms learned in
other courses. For example, the students had to tie into their
biochemistry mechanism the concepts of osmosis, diffusion and
apoptosis as learned in physiology, or the structural proteins
used in the basement membrane of capillaries as learned in
histology.
The students were free to work together in groups outside of
class time and this was highly recommended. Students were
instructed that they should be able to successfully answer the
case questions with information obtained in the lectures, course
notes, course textbook, and supplemental material. Because the
students were free to use any source of information, they were
cautioned about the use of non-reliabl e i n t e rnet sources.
In the second session the students presented their learning
issues in a large group setting, and the instructor illustrated the
mechanisms on the write on/wipe off board at the front of the
class. This illustration was solely created based on the input and
flow of information from the students. At the conclusion of the
second session another two to three learning issues were given
to the students to be taken up the following week.
The clinical case study process represents an opportunity for
the student to review, reinforce and gain a greater comprehend-
sion of the biochemistry covered in lecture. To keep the stu-
dents involved in the process, enough weight was placed on the
midterm and final exams in regard to the case studies so that
each student valued the importance of successfully completing
the learning issues and attending the large group classes. The
NUHS IRB committee reviewed this descriptive project and
deemed it not to fall under the IRB auspices as it is not re-
search.
Case Study Example 1
This clinical case study used a protein malnutrition case to
focus on the biochemical topics of proteins, amino acids and
enzymes.
MJ is an 81 years old white female who lived alone and was
found lying on the kitchen floor by her son. She was confused,
disoriented and had great difficulty walking because of weak-
ness. She appeared thin and frail, with significant muscle wast-
ing. Her son periodically checked in on her and brought her
groceries, but she has only been eating Saltine crackers and
drinking tea for the past couple of weeks. She stated that she
experienced difficulty swallowing and easily got heartburn after
she ate. She had lost more than 25 pounds in the past couple of
years. On physical exam she weighed 81 lbs, and her height
was 5’2”. Her temperature was 99˚F; blood pressure 105/80;
heart rate 62 with an irregular rhythm and respiratory rate of 16.
Her skin was pale and dry, with many small perfectly round
pinpoint purplish red spots on her arms, hands and legs. Her
hair was dry and thin; the temples were sunken; the tongue was
reddened with several small ulcers, and there were ulcerations
at the corner of her mouth. There was moderate pitting edema
of both feet and ankles. She was hyporeflexive and there was
decreased bilateral vibratory and position sense in the feet. A
chest exam revealed decreased breath sounds in the lower right
lobe and a chest X-ray indicated consolidation in the lower
right lobe.
This clinical case study allows for students to investigate
proteins biochemical role in both structural (i.e. collagen) and
functional (i.e. enzymes) physiology. This case study also al-
lows students to investigate the role of co-enzymes and relate
certain vitamin and mineral deficiencies to the patient’s signs
and symptoms. The learning issues posed to the students for
this case included:
• What is the cause and mechanism pertaining to the bilateral
swelling of both lower extremities?
• What is the cause and mechanism behind the multiple small
perfectly round pinpoint purplish red spots (petechia)?
• What is the cause and mechanism related to the develop-
ment of her pneumonia?
• What is the cause and mechanism of her swollen reddened
tongue and the ulcerations at the corner of her mouth?
• What are the physical, psychological, social and economic
Copyright © 2012 SciRe s .
1174
