The Laws of Medicine by Siddhartha Mukherjee Page A

the woman’s abdomen and closed the vessels shut. The patient was safe, but the resident looked devastated.
    But then, it was as if a tiny bolt of knowledge had moved, like an electric arc, between Castle and his resident. The resident modified his approach. He walked over, past the surgical drapes above the woman’s head, to confer with the anesthesiologist. He confirmed that the anesthesia was adequate and the patient was safely sedated. Then he returned to the surgical field and blotted out the remnant blood with some gauze. Now, he began cutting around the blood vessels when he could, charting their course with the tip of his Babcock forceps, or separating them with his fingers with exquisite delicacy, as if polishing the strings of a Stradivarius. Each time he neared a blood vessel, he turned the blade of the scalpel to its flat side and dissected with his hands, or moved farther out, leaving the vessel untouched. It took significantly longer, but there was no further bleeding. An hour later, with Castle nodding approvingly, the resident closed the incision. The tumor was out.
    We walked out of the operating room in silence. “You might want to go and check her chart now,” Castle said. There was a note of tenderness in his characteristic nasal twang. “It’s easy to make perfect decisions with perfect information. Medicine asks you to make perfect decisions with imperfect information.”
    ....

This book is about information, imperfection, uncertainty, and the future of medicine. When I began medical school in the fall of 1995, the curriculum seemed perfectly congruent to the requirements of the discipline: I studied cell biology, anatomy, physiology, pathology, and pharmacology. By the end of the four years, I could list the five branches of the facial nerve, the chemical reactions that metabolize proteins in cells, and parts of the human body that I did not even know I possessed. I felt poised to begin practicing real medicine.
    But as I advanced through my training—becoming an intern, then a resident, a fellow in oncology, and then an attending doctor treating patients with cancer—I found that a crucial piece of my education was missing. Yes, I needed the principles of cell biology to understand why, say, a platelet transfusion lasts only two weeks in most patients (platelets live in the body for only about two weeks). Anatomy helped me recall why a man had woken up from a surgical procedure with his entire lower body paralyzed (an unusual artery that supplies the lower spinal cord had become blocked by a clot, resulting in a “stroke” of the spinal cord, not the brain). An equation from pharmacology reminded me why one antibiotic was dosed four times a day while its close molecular cousin was given only once a day (the two chemicals decay at different rates in the body).
    But all this information could, I soon realized, be looked up in a book or found by a single click on the Web. The information that was missing was what to do with information—especially when the data was imperfect, incomplete, or uncertain. Was it appropriate to treat a forty-year-old woman with acute leukemiawith an aggressive bone-marrow transplant if her health was declining rapidly? At first glance, textbooks and published clinical trials gave you an answer. In this instance standard wisdom held that patients with declining health and performance should not be given a transplant. But what if that answer did not apply to this woman, with this history, in this particular crisis? What if the leukemia itself was causing the rapid decline? If she asked about her prognosis, I could certainly quote a survival rate pulled from a trial—but what if she was an outlier?
    My medical education had taught me plenty of facts, but little about the spaces that live between facts. I could write a thesis on the physiology of vision. But I had no way to look through the fabric of confabulation spun by a man