For many doctors, unfortunately, that is NOT the question. Obviously you send the lab. Send a few labs. Send all the labs. Every test you can run! Then, while all that blood work is processing, get ALL the imaging. Basically, do ALL the things! Get ALL the answers!
That’s ridiculous. You probably knew that as you were reading it. A large number of you, though, have done this exact thing one more than one occasion. Whether it’s the inpatient unit, floor, urgent care, or ER doctors are obsessed with getting labs. ERs tend to be the worst offenders. In many ERs (Especially very busy ones) protocols are in place that specify laundry lists full of labs and imaging studies based on chief complaint before a physician even sees the patient. This leads to a lot of expensive and unnecessary medicine. Since I’m a pediatrician, I’m going to focus on pediatrics, but the problem is just as common in adult medicine.
Case: A 6 year old male comes in to the ER complaining of “belly pain” for the past 2-3 days. When you ask him to rate the pain on a scale of 1 to 10 he looks at you like you’ve got 3 heads and replies, “I don’t know. It hurts.” Patient and mother both deny vomiting, diarrhea, fevers, and dysuria. On further history the child says he hasn’t stooled at all in the past week. Physical exam reveals mild left lower quadrant fullness and tenderness. How would you like to manage this patient?
Case Discussion: This child has constipation. A few of you folks with no medical training even knew that one. When this patient presents to a clinic or to your private practice, you give him the constipation cocktail du jour and send him on his merry way. When this patient comes to the ER, there’s a good chance he ends up with an abdominal x-ray. An x-ray I’m confident he does not need. FYI, I gave this patient an enema last night and when he got out of the bathroom the first thing he said to me was, “WOW! I didn’t know you could poop that much!” I also sent him home with some Miralaax.
Moral: Trust your clinical judgment. Not every diagnosis can be made without labs and imaging. I’m not saying you never need to do labs, but before you order tests get a good history and do a thorough exam. Then order the labs and imaging studies that will help lead you towards the answer. A good rule of thumb is to ask yourself, “Will the result of this test change my course of action?” If the answer to this question is NO than chances are you don’t need that test. (Note: There are corner cases where you need to get the test anyway, but we’re not talking about that here.)
Bonus Tidbit: Don’t send a lab just because you have the blood. This is a common pitfall in pediatrics where it can be difficult to obtain blood from smaller patients. Your patient needs a CBC. You find a big, fat vein and draw a few extra mL’s of blood and tell yourself, “As long as we’ve got some extra blood we might as well send chemistry, sed rate, CRP, liver function tests, and a cooties titer.” Sending extra labs you don’t need only leads to wild goose chases. The chemistry is hemolysed and the potassium is high. You get another chemistry. The potassium comes back fine, but the sodium is a bit low. You get another chemistry. That chemistry comes back QNS (Quantity not sufficient). See what’s happening here? If you had only left the extra blood in the patient you wouldn’t have gotten yourself into this mess.
OK. I’m done rambling. Thoughts?