how doctors think, a dual pathway

A friend calls today and says that another person is bleeding and yet they have been set up to be seen Monday. Why isn’t this an emergency?

Based on the limited information the friend tells me, I agree with the doctors. It is NOT an emergency and I explain why. It is uncomfortable for the person because it may be cancer. Why is that not an emergency?

Let’s use chest pain in the emergency room as an example. Doctors have two brain tracks that are triggered simultaneously by every patient. The first one is “What could kill this person in the next five minutes?” The second is “What is common?” Common things are common and more likely. In medical school the really rare things are nicknamed zebras. You know there are a lot of horses but you can’t miss the zebra. I suppose that in Africa the common things are zebras and the rare ones are orcas or something like that.

Anyhow, the killers for chest pain are heart attacks, sudden death. But there could also be a dissecting aortic aneurysm, where the largest artery in the body is tearing. That person can bleed to death really really fast and that is a surgical emergency. No doctor wants to miss it. There could be a pulmonary embolism, a clot blocking the lung. Chest pain could be from a cancer. A very rare chest pain is from the valve leaflets in the heart tearing so that the person goes in to flash pulmonary edema. And there is Takayasu’s Arteritis, “broken heart syndrome”, where the heart suddenly balloons in size and again, heart failure ensues. Heart failure is actually pump failure, so fluid backs up in the lungs or the legs or both. It is usually slow but rarely very fast and dramatic. A collapsed lung can also cause a lot of pain. And my list is still not complete, I haven’t mentioned pericarditis or myocarditis or a compression fracture.

The common things do include heart attacks, but also anxiety, musculoskeletal problems, inflamed cartilage of the chest wall, fibromyalgia flares, broken ribs, trauma and other things. I was very puzzled in clinic by a woman with pain on both sides of her lower chest wall. In front but cutting through her chest. I ruled out many things. I thought that it was her diaphragm. I sent her to a rehab doctor for help. The rehab doctor sent her to radiology. She had a compression fracture of her spine and the nerves were sending pain messages on both sides. That was not even on my “differential diagnosis” list, because she had no back pain at all. My list changed that day.

Physicians and nurse practitioners and physicians assistants and registered nurses and licensed practical nurses and medical assistants are all trained to think of this differential diagnosis. We are alerted by the history and have to think down both pathways. Last year working as a temporary doctor, the medical assistant came to me saying, “This patient’s blood pressure is 80/60.” “Is he conscious?” I asked, as I went straight for the room. “Yes, he’s talking.” He WAS talking, which means that he’s gotten to 80/60 slowly or is used to it. His heart rate was fast, up near 120. I immediately had him drink water and keep drinking, as soon as he denied chest pain. The problem was dehydration: he was developmentally delayed and had only had one cup of fluid that day and it was now midafternoon. I spent time explaining that he needed 8 cups each day. Not more than that, because if he had too much fluid, it would lower his sodium and make his muscles weak. Most days he drank 3-4 cups. His chart graphed the problem: some days he had normal blood pressure and a normal heart rate. Other days his blood pressure was below normal and his heart rate was fast, his heart trying to make up for the low level of fluid. Cars don’t do so well when there is almost no oil, do they? His kidneys were affected as well. I asked him to drink the 8 cups a day, discussed the size of the cup (not 8 gallons, please) and then recheck labs in 2 weeks. If his kidneys did not improve, he would need a kidney specialist. It turned out that he had nearly fainted that morning in the waiting room. His group home person admitted that no one had noticed that he really was not drinking fluid. I thought that the patient understood and would try to drink a better amount of fluid.

So back to the person I was called about. Infection has been ruled out. This is blood in the urine. A kidney stone has been ruled out, but there is something in the kidney. This is urgent, but if the person is not bleeding hard, it is not emergent. When there is blood in the urine it does not take very much to turn it red. If there is a lot of blood, that can be an emergency, but from the story I got third person, it’s not very much. The emergency things are ruled out but there is still not a clear diagnosis. Yes, cancer is one of the possibilities but it could also be benign. Now a specialist is needed to figure out the next step and the differential diagnosis, the list of things it could be. They will order tests in the same dual order: what could kill this person quickly and what do we need to rule out as common? People often can be very anxious during this period, which is normal. The person says, “I don’t care what it ISN’T, I want to know what it IS.” But sometimes it is a zebra and it takes a while to get to that specific test.

Another example is a woman that I sent to the eye doctor. The optometrist thought it was something rare and bad. He sent her to the opthamologist, who ruled out the first thing, but thought it was something else rare and bad. He sent her to a retinal specialist. The retinal specialist ruled out the second rare and bad thing and said, “No, you have something very rare that is benign.” My patient said, “I have three diagnoses. Who do I believe?” I replied, “No, you have one. The optometrist knew it was unusual and sent you to an eye doctor. The eye doctor know it was unusual and sent you to an even more specialized eye doctor (a “sub specialist”. We keep them in basements.) Now you have a diagnosis. It was a scary process, but I think you should focus on the third opinion because hey, she said it’s benign and it won’t hurt you! That is the best outcome!” She thought about it and agreed. The process was frightening but the conclusion could not have been better.

For the Ragtag Daily Prompt: disquieting.

5 thoughts on “how doctors think, a dual pathway

  1. Lou Carreras says:

    I was occasionally able to attend rounds and grand rounds at one hospital I worked at, thanks to a friendly chief resident. It was both educational and transformative for me back in the OR – understanding the process clarified why we did the procedure and the surgeon’s approach.

  2. curioussteph says:

    Good explanation of the diagnostic/rule out tree. Not knowing is the hardest for most of us. And as I used to remind my patients, even as its difficult to wait sometimes, its better than being the person that has bumped up to front and center.

    • drkottaway says:

      I walked into the ER once and the ER doc was running codes in two rooms. I started seeing other patients to help while he stabilized those folks. First room I walk into the patients says, “I’ve been waiting an HOUR for my sore throat, what is the matter with your people?” I said, “I just stepped in to help because the ER doc is trying to keep two people from dying. I can have you wait for him if you want.” He was much more polite after that. People hate waiting in the emergency room, but it is worse to be the one who jumps the line because they are dying.

    • drkottaway says:

      And thank you.

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