On Reading Harrison’s Principles of Internal Medicine for the Last Time – Chapter 3
Chapter 3 Decision Making in Clinical Medicine
This was a difficult chapter for me and made me recall my first reading of Harrison’s. I didn’t understand it on first read but I appreciate the significance and if I wasn’t a busy clinician, I could spend a lifetime studying this chapter as well as James Joyce’s Ulysses.
The beginning of the chapter was different from forty years ago.
“Every aspect of medical practice is infused with an element of irreducible uncertainty that the clinician ignores at her peril” “Her” would have been thought a typo in 1973. Forty years ago, the field was primarily populated by men. Now over 50% of medical students and residents are women. A big welcomed societal change in the last forty years.
Despite this increase only 15% of academic clinical chairs are women, 16% of medical school deans are women and only 1% of surgical chairs are women. Academe has a way to go.
But I digress.
The crux of this chapter deals with clinical decision making.
Discussed is intuitive vs analytic reasoning
Pattern recognition
Heuristics or rules of thumb which are cognitive shortcuts and prone to error are addressed. Four heuristic types are described.
The third was relevant to me and is referred to as the “anchoring heruretic” and involves insufficiently adjusting the initial probability of disease up or down following a positive or negative test when compared to Bayes theorem i.e., sticking to the initial diagnosis despite the facts or don’t let the truth get in the way.
It recalled my first year in private practice. Though eager, anxious and untested I was summoned to see a young man who was a diagnostic dilemma. He was fourteen years old and developed a vasculitic rash that covered his body. He had blood in his urine indicating an inflammation and disease of the kidneys. At his age I diagnosed Henoch-Schonlein purpura (HSP.) Usually, it is self-limited and the patients do well if you leave them alone.
Surprisingly, his disease persisted, which was not typical, and he continued to have a fever. His symptoms worsened. That was not right. Several days later I did a biopsy of his kidney and examined the tissue under the microscope. It showed a vasculitis or inflammation of the kidney as I had suspected, but there was something unusual, something did not fit with the diagnosis of HSP. The criteria for diagnosing HSP are exact, black and white, and non-negotiable. You can’t hedge. I reviewed the biopsy with a very famous kidney pathologist. The pathologist and I looked through a two headed microscope. The secretes of the boy’s illness were revealed in the red, blue, and silver stained tissue. We looked at another slide specifically for antibodies. To my surprise there was no IgA antibody in the mesangium of the kidney. That was essential to make the diagnosis of HSP. So, by all indications, this was not HSP but something else, and the case became stranger by the day and the child was getting sicker.
“This is Henoch-Schonlein purpura,” the famous pathologist said.
“But there is no staining of the mesangium. There is no IgA antibody in the center,” I said.
“The boy is fourteen years old. He has HSP. This is not Harvard. Here, when you hear hoofbeats think horses, not zebras.”
I was taught to think of both, but kept my mouth shut.
No mesangial IgA meant no Henoch-Schoenlein purpura. That was dogma. But what else could it be? They child was dying.
I went along with the famous pathologist’s assessment because he was a lot older and more famous than I and was a big deal in this community hospital. I thought it best not to challenge his diagnosis. Don’t get off on the wrong foot. Perhaps they did not stain the tissue properly, that happens.
The boy continued to decline. He was febrile and his urine remained bloody. He coughed up blood, his lungs failed, and I put him on a ventilator. This was not HSP I decided but Wegener’s granulomatosis, a deadly disease seen mostly in adults. Ninety percent died in one year without treatment. Today we can rapidly make the diagnosis with a blood test, but in the early 1980’s it was a clinical diagnosis with pathologic support from examination of tissue specimens from involved organs.
I met with the boy’s mother and told her I had the diagnosis. She held on to my arm and told me she prayed in the chapel for God to send a miracle, and that God had sent me. I hoped God hadn’t made a mistake.
“Help my boy,” she said
My throat tightened.
“I will do the best I can.”
At the Harvard hospital I would have had world experts to consult with, not here, maybe someday. I changed course, dismissed the diagnosis of the famous pathologist, and emergently treated the youngster for Wegener’s granulomatosis. It was a difficult, tenuous course but we got the disease under control with steroids and Cytoxan.
Cytoxan is a drug used to treat cancer. It is very toxic like most chemotherapy and can cause severe side effects such as overwhelming infections and death. If the Cytoxan hurt or killed him, it would be because of my treatment. There was no other choice. You always weigh the risks and benefits. I wished my Harvard professors were here.
Every day was a challenge, but he went into remission. He returned to his family and back to school. The storm seemed to have passed. Four months later, and while he continued Cytoxan, he had an epileptic seizure, a convulsion. The disease had recurred in his brain. Once again, he was placed on a ventilator and I increased his dose of steroids.
“Your son will be okay.”
I was confident and I wanted to reassure his mom and decrease the anxiety that was killing her. I could not rob her of hope, and I really was confident. I knew what to do.
He recovered and remained alive and well almost forty years later. It was very special to see the relief in the eyes of family members when you can restore their loved ones to health. It was a look that never got old. That’s when it was nice to be a doctor.
I learned never to accept a clinical diagnosis from a pathologist. They are excellent at what they do and are usually the smartest person in the room. They examined human tissues and organs, but not people. They were not clinicians. They had no contact with the patient and should not give a clinical diagnosis, only a pathologic diagnosis and the possibilities. The final diagnosis is the purvey of the clinician. Respect, but always question authority.
* * *
I learned of another case in a middle-aged man who had Wegener’s granulomatosis. He also presented with seizures following prolonged treatment with Cytoxan and prednisone. I researched further and came across work done by a Doctor Anthony Fauci. Early in his career Dr. Fauci worked with Dr. Sheldon Wolf. They did extensive work on Wegener’s granulomatosis which is now called polyangiitis with granulomatosis. The name was changed because Dr. Wegener was an enthusiastic Nazi supporter. Several German doctors, it turned out, were Nazi supporters, and several diseases, named to honor such men, have recently been changed. I’ve always wondered how doctors, healers, could be enthusiastic Nazis. There were a lot of them on trial at Nuremberg. Germany was a center of medical education, and it perplexed me that humanity, evidently, was not part of their curriculum. Scientific education divorced from moral education resulted in a disaster.
In a paper published in 1983, Dr. Fauci stated that relapse of polyangiitis with granulomatosis (Wegener’s granulomatosis) in the brain does not occur following three to four weeks of Cytoxan. My cases took exception to the observations of Dr. Fauci. I wrote a paper published in the American Journal of Medicine in March 1986 which demonstrated that the disease can recur in the brain despite prolonged treatment with Cytoxan. Today we treat the patient with polyangiitis with granulomatosis as a chronic disease needing treatment for years. You must be alert because the disease can recur in the brain or other organs despite prolonged treatment.
I made a small discovery, not in the same league as Dr. Fauci, but his observations and advice were premature and incorrect not unlike some of his Covid-19 recommendations. Medical science changes and should make us all humble.
During the years that followed I went into the obscurity and the rough and tumble world of private practice in a community hospital while Dr. Fauci is the chief medical advisor to the President. He is also one of the editors of Harrison’s Principles of Internal Medicine.
Discussed further in chapter 3 is clinical expertise and how it is achieved and identified.
“It remains uncertain whether any didactic program can actually accelerate the progression from novice to expert or from experienced clinician to master clinician. Deliberate effortful practice (over an extended period of time, sometimes said to be 10 years or 10,000 practice hours) and personal coaching are two strategies that are often used outside of medicine (music, athletics, chess) to promote expertise.”
I’ve spent countless hours learning to strike a golf ball properly both alone and under the guidance of a professional. It struck me as strange in medicine it was “see one, do one, teach one.”
But then I think most doctors would agree that achieving expertise in medicine or surgery is a bit easier than expertise in golf, billiards, bridge or playing the piano or violin. When you think of it that is a good thing and should reassure us, otherwise there would be too many hacks and too few Tiger Woods.
