A patient is having a endoscopy combo with a colonoscopy. During the colonoscopy they find and remove a few polyps, and take a few biopsies. All of this appears to be routine procedure.
But afterward, a nurse appears bedside and says the doctor has asked that they draw some blood. She proceeds to draw 5 small, separate vials of blood. (It’s possible the patient was told more, but was only just coming round, so doesn’t remember.)
The question is why would they take blood? Especially after? And why so many vials? What could they be looking for?
(I swear, it happened to a friend and made me wonder about it too!)
Blood tests can show a lot of things. I think of them as pretty routine and no cause for alarm.
I had an endometrial biopsy a couple of weeks ago. I asked the doctor, “Aren’t you going to take some blood to test?” I think she was going to wait until the biopsy came back and then do it. But I live really far from her office and I said, “Let’s just do it now while I’m here,” and she said ok. They took four vials. Some medical person can weigh in, but I thought it was in case something happened to the sample, like it got contaminated, or maybe they send them to different places. None of this struck me as out of the ordinary or worrisome.
Good grief! There are probably hundreds/thousands of tests they could do with blood samples.
If still in the hospital, ask the nurse what tests were ordered. Then look each one up on the internet. If gone home, call and ask the Dr.s office which tests were ordered. Ask them to spell each one and write it down, then look it up on the internet.
Also every Dr.'s office / clinic / hospital in my area now allows patient internet access to their medical records. Called “My Care”, “My Chart”, “Patient Portal”, etc. Simply call up your doctor’s office and ask to get access. And/or look on your doctor’s web site. There you will find the test they ran as well as the results. Usually there is a “?” next to each test name and you can click on that, then read what the test is for.
If they ask for a blood specimen seemingly randomly or as an afterthought, there is a possibility that someone got stuck with a contaminated needle or other instrument and they are checking for hepatitis and HIV.
Consent for this is covered within the general consent the patient signs at registration, so no explanation is usually offered.
mmm
If they took a few polyps out, they probably want to do a blood test for CEA (the colon cancer tumor marker) to see if it’s elevated or not - that can help confirm a diagnosis if one of the polyps is funky.*
*Official medical term.
Different vials are used for different tests. For one reason there are different kinds of preservatives and anti-coagulants in the vials that have to be compatible with different tests. Also the vials are often plugged directly into a testing device and won’t be moved from device to device. So the number of vials of blood taken isn’t necessarily about volume at all, it’s more related to the number of tests taken and the special requirements of those tests.
Usually blood work is done before a procedure. Maybe someone forgot, or it was considered desirable to do followup testing based on what the initial tests showed, or even as a result of endoscopic findings (as one example, there’s a blood test used to help confirm a diagnosis of celiac sprue).
CEA levels generally are only considered useful in long-term followup after someone has had definitive treatment (i.e. surgery) for colon cancer - if the level starts rising, it could indicate recurrent or metastatic disease.
On the other hand, CEA is a lousy screening test for colon cancer in people who’ve never had such a diagnosis, and does not help confirm the diagnosis if a polyp looks “funky”.*
There’s a blood test for IBS which is relatively new. Depending on why you had the colonoscopy, they may want an IBS test, and also a venous iron level-- I had a colonoscopy/gastroscopy after I had come up iron-poor several times and diet and iron pills had not helped, so they wanted to look for causes of malabsorption.
I have to take liquid iron supplements now, which insurance pays for, and which is better-absorbed than pills. I also had to back way off the amount of ibuprofen I was taking for arthritis, and that actually seemed to help a lot. I had no idea ibuprofen could interfere with iron absorption. I get prescription tramadol now, which doesn’t work as well.
Gastroscopy and colonoscopy are used to screen for cancer, ulcers/IBD and investigate anemia (loss of blood, often from the GI tract). Blood work would include a CBC to look for hemoglobin or hematocrit levels. More detailed tests for anemia might include a reticulocyte count, serum ferritin (iron level), folate, vitamin B12, iron binding capacity, various cancer markers, markers for celiac disease, H. Pylori for gastric ulcer (but usually biopsied if doing scopes), markers for general inflammation…
But most of these tests are done before. Might just need a CBC, if that. Maybe the bloodwork was not done, was not available, something was seen that triggered a second thought or something was forgotten (eg patient is on blood thinners and wish to document INR).
Interesting. Someone got a needlestick during my brother’s heart surgery and they asked us afterward if it would be OK if they tested. I’m sure they would have anyway, but I guess it was a courtesy to ask.
