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Diagnosis Deconstructed

Diagnosis Deconstructed: De Humani Corporis Fabrica

Morchi, Ravi MD

doi: 10.1097/01.EEM.0000406947.13242.fc
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    Night. It was dark outside when the mother arrived with her son. I thought this was odd. Why had she chosen to trek to the hospital at night? Most patients do not arrive in the dark because this is a dangerous place to travel. Mom must have felt the trip would be worthwhile. Whatever was ailing her son would be serious enough to bring a villager and her child out at this hour.

    He was her third-born, and at just over a year old, normally quite active. For the past day, however, he had done nothing but sleep. She could rouse him briefly, but then his eyes would drift down, and he would promptly fall back asleep. He cried and screamed occasionally before resuming his slumber.

    Primary Assessment. He was well nourished, no signs of kwashiorkor or marasmus. Arousable by painful stimulation, he would cry, briefly gaze in your direction, and then drop his head back down on the cot.

    Airway patent and protected. Breath sounds clear, unlabored, and with normal chest rise. Extremities warm and capillary refill normal. Pulse fast, with a rapid upslope and descent.

    Localization versus withdrawal. Isolated and without options for cerebral imaging, I submit this as the single most important point on the coma scale. A withdrawal reflex to painful stimulation means that the spinal cord has been liberated from control centers in the cerebrum, basal ganglia, and cerebellum. Pinching the toes or pinching the thigh resulted in a triple-flexion of hip, knee, and ankle. When free from upper motor neuron regulation, this reflex predominates. A similar reflex arc in the arms produces elbow flexion, supination, and shoulder adduction; if severe, we term this a decorticate posture.

    When we pinch our child, he fortunately does not simply withdraw. In response to the thigh, the boy extends at the hip and knee, attempting to move his limb away from the anterior, painful stimulation. The pain stimulus makes its way up the peripheral nerves to the cord, brainstem, and then the medial portion of the contralateral cerebral sensory homunculus. The result is a coordinated response from the sensory and motor association areas and a meaningful, purposeful movement of the leg away from the stimulus. At the bedside, I could see the medial cerebral hemisphere working. The patient -localized to pain.

    One point on the scale and the implication that a functioning cortex digests a great amount of neural data. Noting localization upon stimulation of other limbs, I see the remainder of both cortices working. For now, no need to drill empirically for extra-axial blood or pus.

    Instead, the problem may be diffuse encephalitis, an encephalopathy whose origins lay outside the CNS, or a focal extra-axial problem that has yet to culminate and require mechanical decompression.

    Moving on. Pupils 3 mm and sluggish. Neck supple, no meningismus. Without a CT or toxicology labs, I pondered the need for a lumbar puncture. Would I commit this child to a full course of antibiotics if I found a handful of white cells? In our rural setting, we have no bacterial cultures, and antibiotics for CNS disease are used sparingly because supplies can run low. Chloramphenicol has historically been our best bet. Even so, we must consider the nonresponsive pathogens: mycobacteria, protozoa, and viruses.

    Genitourinary area normal in appearance. Skin without rash or evidence for Trypanosome inoculation. Abdomen slightly distended, no tenderness, no guarding. Rectal vault full with a firm, overinflated, tubular “balloon.”

    What?

    Exploratory Laparotomy. Truthfully, I was not certain of the diagnosis at this point. But I had a suspicion, and there were no better options than to look. Under ketamine in the operating theater, it was still unclear to me what I was looking at. Was it the disease I suspected? Or something else? It lay in my hands, right under my nose, and yet I was unsure.

    Andreas Vesalius. Considered a father to modern medicine and surgery, Vesalius was a Belgian scientist of the 16th century who said something quite remarkable for his day. He stated that being a physician meant you could not simply read out of a textbook or look at pictures. The visual imprint of words or numbers would never give you an accurate understanding of disease.

    To be a physician, Vesalius said, one had to get off the pulpit to experience the human body post-mortem. With hands on cirrhotic liver, infarcted myocardium, congested lung, dead bowel, calcified aortic valves, and sclerotic arteries came an appreciation for disease that no words could supplant. A tangible, colorful memory of illness: its compliance, texture, and smell.

    It was on this platform that Vesalius compiled his anatomic dissections into the most comprehensive and detailed description of the human body yet seen: De Humani Corporis Fabrica. It would later be the foundation for bedside clinical diagnosis and our modern medical system.

    Medical school, again. We start medical school with anatomy because Vesalius said we should. Our problem today is that we do not end medical school with anatomy. We do not reintroduce anatomy in a purposeful way later in our career. Years pass without the opportunity to experience the pathology we chase. Inflammation is quantified and digitized, numerical cutoffs memorized, and we wait anxiously for the appearance of lines on an electrocardiogram or pixels on a screen to declare our patients ill. As modern-day clinicians in a subspecialized system, we are deprived the acquaintance of diseased tissue.

    Myself. I could have told you all about the diagnosis that our child had. I could speak of the incidence, prevalence, risk factors, mortality, classic presentation, appearance on radiograph, preferred treatment, and indications for surgical exploration. Just prior to opening his abdomen, I thought I knew all there was to know about this disease … until I saw it.

    Until I felt it.

    Until I looked and stared, perplexed by this mass in my hands that felt like one limb of a balloon animal.

    It didn't look like I had imagined. It didn't feel like I had imagined.

    Memorization of numbers, data, pixels, and medical terminology in all years prior did not help me now. Back home, digitization had distanced me from disease, and I would only come to see this truth in rural Africa. No amount of reading or writing would make me understand. Only with direct visualization and palpation did I know what intussusception really was.

    Reduction. I reduced the intussusceptum from the intussuscipiens by compressing the distal, nondistended rectum between thumb and forefinger. The intussusceptum had peristalsed all the way through the distal colon and was palpable on rectal exam. If I had waited longer, it would have appeared as a rectal prolapse. By squeezing the bowel just distal to the lead point, you can milk the lead point all the way back to the initial juncture of intussusception. This is a slow and careful process. Once back, I noted it was a colocolonic intussusception, not ileocolic, and there was no mass to serve as the lead point. Fortunately, the colon appeared viable.

    Expectations. Sometimes, we are surprised by an obvious abnormality on physical exam. But more often, we find what we expect to find: nothing. If we go in with the attitude of rehearsing these maneuvers and foresee none of them to have any input into decision-making or management, then they won't.

    Conveniently for us, when we come out of the exam room with nothing in particular, we substantiate in our minds that the physical exam is not that important. That it lacks sensitivity or specificity. That it is not as good as a CBC or lactate. In select instances, this is true. But in general we may undervalue the physical exam by not performing it thoroughly, not performing it with the expectation of finding something subtle.

    I will tell you that before meeting intussusception, I examined infants' abdomens with low expectations. Consequently I never felt a sausage-shaped mass. After knowing intussusception by touch, I deliberately search for and occasionally find that tubular balloon animal.

    Andreas Vesalius was correct. Experiencing the pathology imparts a clinical touch. A touch that technology cannot lend us. A touch that need not require travel to a distant land but only a desire to know illness in its true form and a collaborative effort with our pathologists at autopsy.

    Comments about this article? Write to EMN at[email protected]

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    Dr. Morchiis the director of the Medical Screening Examination program at Harbor UCLA Medical Center and an assistant professor of emergency medicine at UCLA's David Geffen School of Medicine.

    © 2011 Lippincott Williams & Wilkins, Inc.