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The Uncharted Sea
Vardaman M. Buckalew, MD
The Uncharted Sea was revised for Oasis from an address to the Fourteenth Annual Fall Convocation of the Class of 2003 on November 4, 2000, otherwise known as the "White Coat Ceremony".
We are here today to celebrate your coming graduation from the pre-clinical curriculum. You have begun to see real patients in your physical diagnosis course, and in just a few months, you will actually be allowed to “play doctor”. That means you will begin to assume the awesome responsibility of diagnosing and treating people with various medical problems who come to this institution for help. I am certain this is the opportunity you have all been waiting for, the real reason you came to medical school in the first place.
As you reflect on your transition from the formal preclinical education to the more informal training you will receive in the clinical setting, I ask you to consider this question. What is the impact of your training in basic biomedical sciences in these first two years of medical school? My own experience has been that a persistent, lifelong interest in the basic biologic mechanisms of disease has helped me to be a better physician. Let me explain.
Physician-patient encounters always involve some element of a process we call "clinical reasoning" on the part of the physician. Currently at Wake Forest Medical School, clinical reasoning provides the basis of the problem-based curriculum, is taught in the small groups in both the first and second years, and tested in the Standardized Patient Assessment or SPA exam. Given a history and physical examination, you identify the patient’s problems; then you develop mechanistic hypotheses that might explain the patient’s problems. These hypotheses must be based on your knowledge of pathophysiology, the science of abnormal function of biological systems, and the clinical manifestations that result from these abnormally functioning biological systems. Next, you order a series of tests to confirm or deny your hypotheses and finally, based on the results of these tests and the abnormal mechanisms you can identify, you proceed to a series of diagnoses and their appropriate treatment.
The thought process of clinical reasoning is exactly analogous to the process by which laboratory scientists operate. They develop hypotheses and plan experiments based on their own and others' observations. In the case of both the scientist in the laboratory and the clinician at the bedside, a successful outcome depends on depth of knowledge and reasoning ability. The medical scientist must have extensive knowledge of basic biology, the clinician of pathophysiology. Pathophysiology is the basic science of clinical medicine.
 The application of the scientific method to patients at the bedside was developed in Europe in the middle of the 19th century and was first emphasized in American academic medicine in the late 19th century by the eminent clinician Sir William Osler. Osler was Canadian by birth and training and, although he is most famously associated with Johns Hopkins, his first academic position in the United States in 1884 at age 35 was Professor of Medicine at the University of Pennsylvania. As a medical student at that school in the mid 1950s, I experienced first hand the impact a legend can have on the culture of an institution. It was as though he were still there, guiding faculty and students through the medical education process!
Osler was a master teacher and writer, who taught in the clinic, at the bedside and in the autopsy room. Recognizing that medicine at the end of the 19th century was long on clinical reasoning and short on therapy, Osler is alleged by tradition at Penn to have said: "I can offer patients a complete history, a thorough physical examination, and a meticulous autopsy". Although this aphorism was undoubtedly created by some of his students as a caricature of his method, Osler was a legend in his own time in part because he so often proved to his students at the autopsy table that what he induced from a careful history and physical examination, an appropriate laboratory investigation, and an encyclopedic knowledge of the clinical manifestations of disease, was indeed correct.
The modern version of Osler's apocryphal aphorism might be: "we can offer a brief history and physical examination, extensive laboratory testing, and a CT scan of everything". We hope that by scanning and testing everything we won't miss anything big, and there may be some merit to that approach in some situations. However, hypothesis driven laboratory investigations based on sound clinical reasoning has, in my experience, proved to be a more successful approach in most instances.
Clinical reasoning is hard work which tests not only your observational skills and reasoning ability but your knowledge of pathophysiology.  The exercise involves more than looking up the differential diagnosis of some abnormal finding on the internet. To paraphrase a famous quotation from Osler: to observe the phenomena of disease without extensive knowledge of the pathophysiologic processes that produce such phenomena is "to sail an uncharted sea". (Osler's original quotation was: "To study the phenomenon of disease without books is to sail an uncharted sea, while to study books without patients is not to go to sea at all".)
As physicians, we tend to derive the most personal satisfaction from healing patients by applying one or more therapies to conditions which have already been diagnosed (hopefully correctly). I would hope, however, that as you mature professionally, you will come to enjoy being competent in clinical reasoning for the sake of being competent, as well as for the sake of your patients.
I well remember one of the first times I experienced the pleasure of feeling competent in clinical reasoning. As an intern at the Hospital of the University of Pennsylvania, I was on duty in the emergency room one Sunday afternoon when a young African American female came in complaining of severe abdominal pain. She had never been seen there before and had no history we could obtain of any previous illnesses. The physical examination was notable for three things: she was obviously in very severe pain, she had a very loud cardiac murmur, and her sclerae were very pale; that is she appeared anemic. Given this constellation of signs and symptoms, it is obvious to you that the list of possible diagnoses is quite long and at least some of those possibilities should be running through your mind right now.
Be that as it may, I decided to pursue the possible anemia for two reasons: first, it was easy to check; and second, I remembered that anemia could cause cardiac murmurs. I wanted to follow the widely practiced principle known as "Occam's razor", of explaining complex clinical phenomena by the fewest possible causes. I didn't ignore her abdominal pain, but a careful physical examination convinced me she did not have an intra-abdominal catastrophe and that I had time to pursue the apparent anemia.
When the blood count showed she was indeed anemic, I proceeded to do a blood smear. We did our own in those days and I had just spent some time in the clinical laboratory learning to read them. Much to my surprise, the smear was loaded with sickle cells and the diagnosis became obvious: her entire clinical picture could be explained by one condition, sickle cell anemia in crisis.
I thus had the immense personal satisfaction, as a new intern, of being able to call the admitting upper level resident to say that I had a patient with newly diagnosed sickle cell anemia in crisis who needed admission. The patient benefited by having a correct diagnosis made in a timely fashion, allowing her to receive the proper treatment without a long delay. Her HMO, if there had been one in those days, would have been happy because we did not have to order a large number of expensive tests. I felt good knowing that Osler was looking over my shoulder with an approving smile.
Of course, one must always be alert to the possibility that there might also have been some serious intra-abdominal process to explain the patient's abdominal pain. One can never be absolutely certain that a single cause is the only explanation for a set of complex clinical phenomena. The counterpoint to Occam's razor is "Hickam's dictum" that "patients can have as many diseases as they damn well please". With that truism in mind, it would at least be understandable if that patient I described had had several thousand dollars of laboratory tests before anyone attempted to synthesize the information obtained from a history, physical examination, and a few simple laboratory tests. The process of systematically proceeding through a hypothesis driven investigation is often ignored in today's busy, litigious environment.
The successful clinical encounter such as I have described provides a further benefit to the patient that may not be obvious to you at this point. Patients recognize competence, or lack thereof, in their physicians! Patients also recognize, and react negatively, to arrogance, so one's competence must be cloaked in appropriate humility. The more proficient you are, the more confidence the patient will have in you; and patient confidence is very beneficial to making the patient well. Healing is not always just a process of making the correct diagnosis and applying the most appropriate therapy. Patients are more likely to follow your advice if they sense your competence. It is truly a satisfying experience to see your patients healed, and to know that your professional competence, and the patient's confidence in that competence, contributed to their healing.
So, my friends and fellow students enjoy your exposure to biomedical science; learn as much as you can now about basic mechanisms of disease. Then, become life-long learners not just of therapy but of basic pathophysiology and its application to the investigation of hypotheses at the bedside. Both you and your patients will be well rewarded.
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