Diagnosis and the Physician’s Laboratory

Share |

The curriculum renewal committee of the University Of Washington School Of Medicine[1] offers suggestions for curriculum changes that would enhance the numbers of graduates choosing a primary care specialty. Notably the report did not mention the issues of prestige nor the availability and training in the use of diagnostic tools for a primary care setting.

From a clinical viewpoint primary care is more of a science not less of one than the other more limited specialties. The training and clinical tools should match the challenge and they do not. Medical students need both the tools and the training to do serious diagnostic studies. Contrary to the image of a doctor making a snap diagnosis wherein the only problem is the treatment protocol, diagnosis is multifaceted and no simple matter. Multiple conditions, individual patient constitution, and multiple layers of symptoms compound the challenge. Many studies suggest a high percentage of missed and wrong diagnoses, 35.8% in this study.[2] We use to have the autopsy as a final arbitrator of diagnosis but no more. Autopsy has gone out of style; it is not profitable enough. Some medical schools have abandoned the microscope in favor of digital images in training. The microscope, however, remains one of the most essential diagnostic instruments. Today’s microscope should provide polarized light, dark field and fluoroscopy. This is real-time microbiology.

Historically, medical science advanced through the evolution of diagnostic tools and techniques. First, there was the autopsy, then the stethoscope, and the microscope, then statistics, the x-ray machine, ultrasound and more recently bio-molecular science. Today, hospitals excuse the autopsy with reliance on the CT scan. Largely the CT scan replaces the plain old x-ray. This is not progress. Today the stethoscope hangs around the neck unused. Offices send out most lab work, either to a reference lab or to the hospital. It should be obvious that the primary care doctor needs a small clinic version of all of the basic diagnostic tools and some that exist only in research labs. Basic equipment should include ultrasound, microscope, x-ray, and the skills to go with them. Looking to the future, the primary care physician needs to link current clinical research with his or her practice, especially in statistics and genomics. Polymerase Chain Reaction (PCR)[3] should find common use in the clinic; students should have enough undergraduate experience in proteinomics to manage it.

Many frustrations to the practice of good medicine come from outside the profession. These distortions, accepted as the way things are, limit both the role of the physician and his or her ability to diagnose conditions at hand. For instance, EPA limits a physician from conducting many laboratory tests in the doctor’s office, or requires burdensome licensing and exemptions.[4] While well intended to improve quality and control costs, it does the opposite. One fear suggests that physicians do laboratory studies because they produce more revenue. Perhaps some do, but the unintended consequence denies access to simple inexpensive tests. These tests done in real-time, while the patient is present, save time, save money and improve outcome. A trip to the hospital, results in delay and a much more expensive procedure. I cannot imagine a physician doing a gram stain, a peripheral blood smear, stool, a urine sediment, a sedimentation-rate or a culture and sensitivity for the money; although, payment for these services must cover the cost of time and equipment. Some of the tests are time and space sensitive with unstable chemicals and fragile structures, so inaccuracies accrue when the specimen is sent out.

The same argument can apply to office x-ray. The office machine requires the same inspections and calibrations as in the hospital. The machine may be identical. One does not have to use much imagination to see a political undercurrent persuading legislators that everything must be done in the hospital. Unfortunately, hospital profit motivates the lobbying.

In 1998 while on the Board of Directors of the South Peninsula Hospital, I attended a dinner seminar set up by the network of Alaska hospitals including legislators presumably for educational purposes. It had only begun when it became evident that this meeting had the primary agenda of promoting a bill prohibiting office x-ray machines. The program presented undocumented evidence that office x-ray machines were sub substandard and hazardous while hospital machines were new and operated by licensed technicians. Presenters built a case for eliminating office x-ray machines in favor of securing all x-ray business for hospital radiology units. I was sitting at a table next to Senator Murkowski. He turned with a questioning look. I simply compared the cost of flying a patient from a native village to an Anchorage hospital for an x-ray of the chest in order to assess a clinical pneumonia. The unfavorable cost and the poor medical treatment of a time sensitive illness delayed by a trip to the hospital were obvious. The bill did not pass. In today’s environment, a hospital x-ray becomes a CAT scan. The cost is a hundred fold greater and the information only marginally better. The accumulated CT radiation expositor falls into the danger zone.[5] Students should learn the physics of radiology, quantum physics and participate in research for the newer less toxic photonics.

In short, the primary care doctor should be educated as a scientist in the tradition of the great physicians, past and present. He or she needs the tools of science and of diagnosis and be expert in their use. One wonders, just what is the character we strive towards in a primary care physician? Do we want a doc who is indeed a scientist with the humanity of Hippocrates? Or, do we want a Feldsher with an unused stethoscope hanging indolently around the neck?

---

[1] http://www.uwmedicine.org/Education/MD-Program/curriculum-renewal/Working-Groups/Documents/Report-Primary-Care-April-2013.pdf
[2] http://archinte.jamanetwork.com/article.aspx?articleid=1656540
[3] http://en.wikipedia.org/wiki/Polymerase_chain_reaction
[4] Clinical Laboratory Improvement Act(CLIA) 1988 http://www.cms.gov/Regulations-and-Guidance/Guidance/Manuals/downloads/clm104c16.pdf
[5] http://radiology.rsna.org/content/251/1/175.abstract

Microscopy

Share

Microscopy has gone out of style in medical education. Yet schools struggle to revise curriculums for various philosophical goals one of which is providing more primary care physicians. I cannot imagine practicing medicine without a microscope, much less primary care in a rural community.

The microscope needs to come back to medical school for use at multiple levels: Histology, embryology, microbiology and hematology. If students do not use a microscope in school, they will not use one in practice. In a rural clinic without nearby hospital or laboratory support, the microscope becomes once again the essential frontline diagnostic instrument. Reference labs and small hospital l abs will miss many key findings through delay in processing the specimen, temperature variations in the mail, through automation and, sometimes, unskilled technicians.

OK, the Colter Counter now does the complete blood count (CBC). The price is the same, in fact higher, but the Coulter Counter cannot read the peripheral blood smear. Herein lays a great economic advance for the hospital administrator. The Coulter Counter requires less labor and labor at a non-professional and thus lower cost level. On the contrary, however, critical information may be missing. For instance, a college student with swollen glands, a sore throat and palpable spleen might have Mononucleosis or something worse. The peripheral smear, viewed under the microscope, can identify Mononucleosis and differentiate Mono from Leukemia. The automated Coulter Counter cannot. Today if you suspect Mononucleosis, you might request that the pathologist view a peripheral smear or rely on a blood test for Mononucleosis. The Coulter technician is not skilled in producing peripheral smears and the pathologist is expensive. Furthermore, a blood sample sent through the mail degrades with time temperature and handling.

One look is worth a thousand words. There is just no substitute for a direct look at the little buggers. A gram stain may be the best early identification of an organism causing pneumonia. You can instantly classify the bacteria by morphology and staining characteristics as streptococcus, diplococcus pneumonia, staphylococcus, and various others by direct vision. Various fluoroscopy techniques can improve the accuracy of the identification. Knowing what you are treating greatly improves the selection of antibiotics while you wait for the sensitivity tests to identify the agents and concentrations that will do the job. Unfortunately, laboratory technicians are not very good at reading gram stains. A technician will describe everything in order to make sure of covering all the bases. In other words describing everything fails to distinguish the pathogens from the normal flora of the throat and mouth. This requires judgment and experience -- even some clinical correlation. Sometimes the pathologist is not good at this task either – depending on which one you get. In order to contain costs, most hospitals do not have a PhD microbiologist in the laboratory; they rely on the rotating or even visiting pathologist to fulfill that role.

Recent techniques in electron microscopy and fluorescent microscopy overcome the wavelength limitation of light and visualize structures at a molecular or nanoscale level. When I was in medical school, I envied those with binocular viewing and those with a 35 mm camera attached. Today, look for digital imaging with a view on the computer screen.  We can instantly add images to the patient record.  Multiple substage filters facilitate further convenience. Immuno-fluoroscopy offers instant identification of many pathogens.   

One does not need the current level of technology, however, to make use of microscopy in a doctor’s laboratory.  All that is required is good lenses, well aligned with a selection of objective lenses on a rotating head and a good substage light source. Skill in its use is what counts.

An old but very helpful Laboratory manual by Muriel C. Meyers, a hematology professor at the University of Michigan gives detailed instructions for preparing slides. She also includes other office laboratory procedures not requiring expensive reagents.  Some content may be out of date but other content maybe overlooked by today’s hurried and mechanized procedures. This 129 page manual contains many forgotten incites. Clinical Laboratory Diagnosis and Essentials of Hematology, Bethell and Meyers http://babel.hathitrust.org/cgi/pt?id=mdp.39015009566343;view=1up;seq=116

|