I recently admitted a patient with a pulmonary embolism. Before heparin drip was started, my attending ordered a hoard of eccentric, non-indicated hypercoagulable workup in the hope of avoiding the effect of heparin on these test results, including phosphatidylserine antibody and methylenetetrahydrofolate reductase DNA. I watched in horror as the nurse drew out approximately 13 tubes of blood, since each test needs its own tube.
On rounds, the attending of course pimped us about all the possible tests you could draw on a patient who comes in with a clot. I zoned out in my head since I know that regardless of the test results, pulmonary embolism is life-threatening enough that this patient will need life-long anticoagulation - the tests will not change anything. Even if the patient tested positive for genetic clotting diseases, there is no point screening family members or even considering anticoagulation in them unless they develop clots themselves. We went on a long and useless thought experiment. What bothers me the most is that we get a pat on the back when we try to draw these tests just because they are vaguely related to hypercoagulability, but when you actually stop to ask yourself what you would do if the tests come back positive, the answer is usually a shoulder shrug . Imagine the phosphatidylserine antibody came back positive - what does that even mean? and do we even care? I personally do not as the patient is going home with anticoagulation no matter what.
Useless thought experiments, unindicated lab tests and interventions happen on a regular basis, both in my medical school and residency program. We transfuse blood when there is no good evidence that it improves any outcome, just because doctors are nervous that patients will have heart damage from demand ischemia. Consulting surgeons would like to follow Lipase level in my patients with pancreatitis, and my attendings let them even though there is no evidence that its correlates with symptoms just because we don't want to get in a fight. I was told to perform extensive workup in a patient with acidemia, when the obvious cause of kidney failure stares us right in the face - I couldn't convince my attending to wait until the kidney failure resolves to see if the acidemia goes away, at which point no workup will be needed. We looked for zebras even though we know it's a horse, only because my attending "didn't want to miss anything."
In my opinion, most of what we do in medicine is not backed up by good evidence. A lot of the guidelines are biased by group interests and potential profits. This is part of the reasons why some of the tests/procedures that used to be indicated are no longer. Mammogram used to be recommended every year, but now yearly screening may lead to unnecessary breast procedures and once US Preventive Services Task Force tried to recommend increased screening interval, the backlash from groups that stand to profit from mammograms and breast procedures was overwhelming.
But a lot of it stems from how we are trained in medical school and residency. If we get a pat on the back every time we draw useless tests, we will continue to perform unindicated workup when we become attendings. If we are deemed unknowledgeable every time we refuse to do extensive lab work because we have a good explanation of what the abnormality is, we will spend more money without improved outcomes, which is happening in the US as we speak.
I wonder if my patient knew that the test for phosphatidylserine antibody costs $194 at our hospital, and that in the end the test will leave her with nothing better than less blood in her veins.