For 6 years I was a Laboratory Technician in the Air Force Reserves, working all aspects of the laboratory as well as accomplishing "blood draws" (phlebotomy) in every imaginable setting (inpatient and outpatient). I have also worked in the private sector for hospitals, doctor offices, and clinical lab sites. This was my primary field for 20 total years (which began with the Air Force training). I've been in a new career for ten years, though I recall virtually all of my lab science.
Hi Marie518, Great question. There are literally thousands of tests that can be run on blood. But a much smaller number are very very common. And each test generally requires a specific tube. For example, a CBC (Complete Blood Count - used to test for anemia, and other things) needs to be run from a "purple top" tube. The purple top tubes are standardized across the industry to indicate they contain EDTA, an anticoagulant and a preservative. CBC's need to be run on blood that hasn't clotted (thus a need for an anticoagulant or "anti-clotting" compound). Other tests, such as for liver enzymes, require that the blood in the tube actually clots. These tubes are often called "Tiger Tops" (because of their gray and orange mottled appearance) and allow the tech to centrifuge (spin) the tube at high speed to separate off the liquid portion of the blood (which is a requirement for the test for liver enzymes). It is a bit more complicated than this, but that's the general idea. If you were to use only one tube for "all your tests", you would probably get some invalid results (falsely high or low) at best, at worst you could ruin an analyzer.
Hi Bo, Thanks for your question. My experience is in the clinical laboratory, where samples from human patients are analyzed. But analytical laboratories in general can utilize machinery (analyzers) that probably have many things in common. And one of those aspects could be incubation. Some tests require that a sample be incubated or left to sit for a period of time before the testing procedure can proceed. While I have never worked on DNA analyzers, I'm virtually certain that one or more portions of the procedure requires separation and concentration of cellular matter. That alone could take some time. And then there is probably time for the concentrated material to incubate properly for meaningful results. A good analogy is waiting for a bacterial report. In most cases, the bacteria needs time to grow before it can be analyzed, anywhere from 48 hours to 2 weeks on average depending on the organism. If a procedure calls for incubation, it is not a step that can be skipped. And incubation is usually very specific, which is why you have the (sometimes) painfully long wait times, even in high profile cases. As for skipping ahead in line, yes, a lab manager usually has the authority to allow for that, but it might only make a small difference in the end.
Hi LaGrange, I'll begin by saying I am far from being a legal expert, but in general any lab procedure, including it's machinery and the science behind the testing itself, must be approved by the FDA unless they have special waivers (most often, I imagine, for research and development - I worked for a doctor who had special waivers to research a new therapy, so I know for a fact that it can be done). According to one article I read they do have a waiver, but for only one test (I believe it was for Herpes Simplex Virus I) and beyond that no further approvals. How they can legally test is beyond my scope of knowledge, but apparently they have. And it seems some testing may have been sent to an Arizona main lab, which in general would not be illegal (labs reference out samples all the time for various reasons). This does indeed "smell fishy" as a potential startup company's attempt at raising capital. Fortunately, most if not all doctor offices and hospitals rely on approved procedures. The risk to the public would be hard to assess not knowing the science and proven accuracy (or inacurracy) of the Edison device. With all the negative publicity and larger companies distancing themselves from this fiasco, I'd bet any new startup ventures would be giving it second thoughts.
Hi Bear, It usually takes a lot of blood loss to "feel woozy". I once had to draw 22 large tubes on a 14 year old boy, and he did fine. Blood Banks routinely collect 500 ml of whole blood in about a 20 minute time span and most patients feel ok. The EXACT amount of blood loss is really a question for a physician, because it would depend on the person (age, weight, history, etc.) You should know, however, that most people feel "woozy" because of the psychology of the blood draw. They simply fear it, their blood pressures go down, and they (often, under those circumstances) faint. Most people do quite well fortunately, and rest assured that even many tubes of blood removed is not physically harmful.
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Which cuddly-seeming animals are actually dangerous to be around?Hello Brett, The amount of blood needed for a test depends on a few things. And I think it's fair to say that most of the common tests rarely need large amounts of blood. Current machinery and methods allow for small amounts, often tiny quantities, even in the larger laboratories. So why the "large tubes" anyway? Because the techs who actually do the testing might need more blood later, either to verify high or low results by "re-running" those tests or to do additional testing if the doctor asks for more (this is very common, especially with inpatients, but it can also happen with outpatient samples). In this way, you usually won't have to be redrawn. And statistically speaking, a larger sample would have a better result (though the "smaller sample technology" has been thoroughly vetted so one can rest easy with those results). The smaller samples, such as for home testing for blood sugars, or sometimes in a doctor's office or at a health clinic, are designed as "screenings", for the most part, and the results are "good enough to give you a good idea" of what your level is (whether that be your hemoglobin, your blood sugar, etc.) If I prick my finger and use a tiny drop of blood to check my sugar level on a home device, that result will vary if I do it again on a different finger (20 points difference some times - I've tried it!) but I get the gist of "about" where my blood glucose is, good enough to decide medication and meals. Now on a "big" machine, in a hospital lab? A larger tube of blood, even if rerun, will show way more consistent results (often the same result!) so a glucose level of 120 mg/dl will be 120 mg/dl plus or minus a small deviation every time it's run on that same tube. While it's always good to have that level of accuracy and precision, the smaller samples will usually be good enough to get you by and the doctors know this.
Hi Homer1, An excellent question. Let's take a closer look at what you're asking. Before we can talk about the available TECHNOLOGY, perhaps we should ask about the specific TESTS. Every test, from a simple blood glucose to a blood count has it's own set of protocols and science. Some tests are based on color changes, electrical changes, chemical changes, etc. In theory, an in-home "analyzer" could be created with today's science. In smaller ways it already exists. Diabetics check their blood sugars on a hand-held analyzer called a glucometer. There are in-home tests for ketones on urine, for pregnancy, even for common drugs of abuse. Now, I think you may be wondering why the average household can't have it's own analyzer that does all of the most common blood tests. And the answer is this: Valid Results. Even the largest, high volume analyzers must be checked periodically for statistical drift and other anomalies inherent to the system. In some cases, there has to be calibration (making sure the machine "knows" what a particular value is). Controls have to be run periodically (another feature that tests the machines reliability). How would you be certain that your results are valid? And there is more, much more, not even including the cost of reagents. But let's say you do have this Household Blood Analyzer. And let's say you do learn how to use controls for the, oh let's say, 50 odd tests on-board and have been trained in calibrations and error detection. Great. You draw a blood sample from yourself, put it in the analyzer, and 10 minutes later or so you have results. What then? The analyzer will tell you if something is "too high" or "too low". But only a doctor can interpret those results. And for liability reasons alone (not to mention ethical considerations), your doctor's not just going to take the read out from your machine at face value. He or she would order those tests again, on a certified lab analyzer run by trained professionals. Yes, the lab industry can be lucrative but it's also very competitive. Reps are constantly talking to doctor office managers and even the physicians themselves trying to get contracts for their labs. But none of that has anything to do with an "in-home" system. In the end, it is the validity of your results that can mean life or death.
Hi EnfantTerrible, You ask a question that I'm sure is on the minds of many people. I worked for a short period of time as a phlebotomist/technician in an Air Force blood bank, but as that was some time ago I did a little reading to catch up. Here's the scoop - the answer to the substance of your question, which is really "Can you get HIV from donated blood?" is in the affirmative: Yes, it is possible to be infected by HIV through donated blood. However, as you pointed out, the chances of that happening are incredibly small. So small that the National Institute of Health website quotes the following, "Only about 1 in 2 million donations might carry HIV and transmit HIV if given to a patient." So is the risk of "contracting it this way" worth it? Absolutely. Think of it this way: If you knew that you had a 100% chance of losing your life by declining a blood transfusion and a 1 in 2 million chance of contracting AIDS, which would you choose? Doctors assess risk vs treatment with worse odds than this all the time. As for how "rigorous" the testing is for donated blood products, they are tested for HIV, Hepatitis B and C, syphilis, and other things as well. In some cases they even use more than one process, and more than one "marker" (for example, ANTIGENS - specific viral proteins found on the surface of the red blood cell - versus ANTIBODIES - specific proteins the body produces in response to a specific virus). They make as scientifically sure as they can that the risks are as low as possible. So low that your choice to receive donated blood to save your life should be a "no-brainer".
4. My answer for this question is contained in my answer to your first question.
5. You've likely hit a nerve such as the medial antebrachial cutaneous nerve. End the blood draw and try for the cephalic vein at the antecubital site.
6. Generally you should not wipe the site after using alcohol, you should let it air dry to avoid contaminating the site and potentially causing, though rare, phlebitis.
Hi Juli, Most places have exact protocols in place based on their own laboratory's procedures, and those in turn would likely follow their region's or national guidelines. In general, though, a PICC Line (peripherally inserted central catheter or somtimes called a percutaneous indwelling central catheter) is virtually always in the realm of the nursing department, due to the sensitive nature of this line. As I recall, central lines, PICC Lines, and even blood drawn from I.V. sites (often as a last resort for extremely difficult draws) are all required to be flushed with saline and/or heparin (again, exact protocols are ususlly a function of the particular institution) prior to withdrawal of blood for analysis. That's something most phlebotomists are not allowed to do, only nursing personnel. Also, again, depending on the institution, there may be a waiting period. If the line has an active I.V., I've seen wait times as high as one hour and as low as fifteen minutes. And the wait time can apply to both the cessation (temporarily) of the I.V. AND the flushing with saline and/or heparin, so those wait times can double overall. After the wait period, the nurse usually swabs the port with iodine (and in some places with alcohol first) waits for it to dry, then withdraws the amount of blood required. He or she would then inject the sample into the blood culture bottle (after first having swabbed it with iodine {and in some places, alcohol first}) and invert the bottle a few times to mix well. Doctors most often order blood cultures as a series. For example, "Blood Cultures x3", and the time between each blood culture draw would depend on the institution as well, and even the doctor's preference (I've seen 20 minutes apart, 30 minutes apart, 1 hour apart, etc.) If you're looking for an exact protocol in preparation for an exam, I would respectfully suggest checking with your resources for a clear answer as an exact protocol may depend on that as well. Sorry I couldn't be more precise.
This one had me wondering. Normally, if you've redirected "multiple times" and then blood begins flowing into the tube, it's a good thing (in general, but that presumes you've redirected only a few times and without significant trauma). If the "multiple" redirects were in fact quite numerous and/or traumatic, you'll likely risk having hemolysis in the tube (hemolysis is a central theme in most blood draws) and of course redirecting, if done wrong, can be very painful for the patient and can leave horrible scarring and even an extremely painful hematoma. Also, I'm taking an educated guess here, the reference in your question to "blood spurts" COULD mean that a phlebotomist redirected too deeply and has compromised an artery. Arterial blood in vitro is cherry red and very different from blood from a vein in appearance. Again, trying to cover all bases. And the risk for an arterial draw by a phlebotomist who is not certified for that procedure is a very nasty hematoma for your patient, or worse, depending on the patient's condition.
Hi Alicia,
Your question is a perennial scenario for phlebotomists. Over the years, I finally realized that the secret to "redirecting" the needle during venipuncture in an especially well-endowed arm is to be proactive BEFORE that needle even touches the skin. By this I mean, have the patient make a fist around a large object, one that fits the relative size of their hand. In the past, I've had patients use everything from a few hand towels to a few large (unused, needle-less) syringes. This creates, in effect, a larger fist, one that can exert more pressure per square inch than just a hand without this assist. Then, and this next part you need to be careful about (I'll explain that in a moment), you tell the patient that the tourniquet is going to be "really tight" so that you can "see" the vein better. Now tie that tourniquet tight, tighter than usual. But not so tight as to cut off arterial circulation (which by the way is actually fairly hard to do at the antecubital site - but not impossible). Have them open their hand momentarily to check for circulation. You should be able to see blood flow returning to the palm of the hand (turns white to red). You can also feel for a radial pulse if necessary. Finally, have them make a tight fist again around the aforementioned object, and then have them make their arm as straight as possible. You should easily be able to feel a vein. Note: I realize your question asks what to do DURING a difficult draw. My answer would be to ask a fellow phlebotomist or a nurse to re-tie the tourniquet tighter, feel for the vein above the entry site, and carefully redirect. If that's not possible, you'll need to withdraw the needle and try again, preferably at a different vein. Some text books will tell you that tourniquets that are too tight can cause hemolysis in the tubes, and also cause invalid electrolyte levels. I have to say, for the short period the tourniquet is in place, not once did I find this to be true. A tourniquet, tight or otherwise, left in place TOO LONG, will cause the above. I have seen that. But not for short periods. Hope this helps. Best of luck to you.
Blood draws from babies are usually in very small amounts. As as a phlebotomist you know qualitatively that you shouldn't draw large amounts of blood from infants. Most institutes have their own guidelines. One protocol I've seen is (from drgreene.com):
"GUIDELINES FOR PEDIATRIC BLOOD DRAWS"
"...general rule of thumb I use as an outside limit for blood draws, because at these levels of blood loss there can be measurable health consequences. Blood draws in infants and children should not exceed 5% of their total blood volume in any 24 hour period, unless medically necessary. This is a generous upper limit. Ideally it should be less than 3% of the total blood volume, and where possible, micro-sampling techniques to reduce the amount further are preferred. Blood draws in infants and children should not exceed 10% of the total blood volume in any one-month period, unless medically necessary."
* * * * * * * * * * * * * * * * * *
Samir, most of the time I used microtainers for blood draws on infants, whether capillary or venipuncture. These are very small plastic tubes that are, I believe, 0.5 ml when full. Half of a milliliter or even a full milliliter is not much blood for an infant. And I seem to recall that the average total blood volume (TBV) for babies is around 350 ml.
So, in your question, (3) 5 ml tubes is 15 ml total. From my experience that's way more than you'd ever need from an infant, and about 4% of the average TBV. It's probably not approaching hypovolemic trouble, but still an unnecessary amount of blood for the usual testing requirements.
Hi Samir, I'm going to base my answers to your various questions according to real-life experience and also to questions I may recall on any state, military, or local school exams that come to mind. Please note that, if these are questions you have in preparation for any exams or quizzes, you should check for answers in your resources as well, be they hardcover or online. But I don't mind sharing what I know, so...on to your first question.
You asked: "A patient is a difficult draw, so the phlebotomist uses the exact same site each time."
Ok, this is more complicated than it seems. Usually, this refers to an inpatient who may have I.V.'s or a shunt on one arm, leaving only one "good" arm to draw from. It CAN refer to an outpatient also though (less often in my experience) who is a dialysis patient, heroin user, or otherwise has only one arm that is useable for venipuncture. You write "Exact same site". If by that you mean the exact same tiny hole you had just tried but failed to withdraw from, that is not advisable. In addition to the pain this could cause the patient, you are risking hemolysis of the blood sample in the tube, which will likely invalidate glucose and electrolyte readings, just to name a few. You could also cause unnecessary scarring and while rare even local phlebitis. If absolutely necessary (i.e. no veins on the hand, or areas of the arm above or below the antecubital are available), you can use the same vein, but above or below the "exact same site". You will need to hold the previous draw first to make sure it has clotted enough to begin the second draw (3 to 5 full minutes). If that is not possible, I would check with the tech-in-charge about asking a respiratory tech for an arterial draw or a line-draw by a nurse (both methods, I emphasize, would require permission).
As a lab technician and phlebotomist, I was never involved with drug testing of hair samples. I recommend you call a local hospital lab and ask for the phone number of a reference lab that handles this type of testing and give them a call. Sorry I couldn't be more helpful.
Samir, this sounds like a very slow blood draw when using a multi-sample system (such as the BD Eclipse blood collection system). Most commonly this is caused by the tip of the needle not sitting well inside the vein. I'm going to presume that the tourniquet is tight enough (if it isn't, a fellow phlebotomist or a nurse can re-tighten it for you). You should gently and ever so slowly withdraw the needle a bit to allow better blood flow and if that doesn't work, ever so slowly push the needle in a tiny bit farther. Both of these methods are best done while, with your free hand, carefully pulling down on the skin (using your thumb) below the site, to help stabilize the vein. If that doesn't work, you can try redirecting the needle with caution. The risk here is the same as any "slow draw" incident: hemolysis and even blood clotting in the tube or needle before the draw is complete.
Hi Umm, Sorry it took so long to answer your question, I had a family emergency near the beginning of the year. Ok, the short answer: a physician would be the one to ask this question because the over all answer would likely depend on your situation, activity levels, age, history, etc. The longer answer I will give is a generalization that could apply to anybody. Most of the tests you listed (except for "glycemia" - perhaps you meant glycohemoglobin?) would not be affected by a 16 hour fast from food and drink. In general, though, if you were severely dehydrated it is possible that your CBC could show a falsely elevated hemoglobin, meaning that if you are anemic, it could show that you are normal (as one example). Your urine could possibly show a higher myoglobin (if I remember correctly), meaning you are dehydrated. Overall, a 16 hour fast shouldn't affect lab results negatively. As for questions about your health during and after the fast, you would have to consult with a physician.
Hi thanks for your question. My only experience with hair samples was collection. Testing is generally done at specialty labs. But an educated guess would be that any substance found in the hair sample (or any other sample) that clearly doesn't belong there is going to be reported to authorities and viewed with suspicion.
Hi Vacation12, Thanks for your question. I'm going to attempt to answer this in two parts: 1) The "hissing noise" and 2) The "bubble". Firstly, that hissing sound. I can say that in 20 years of drawing blood I have only heard a hissing sound maybe twice during a blood draw, and both times were in the hand of a patient. The needles are very small, and the skin in the hands of many patients are quite fragile, so it is possible that the bevel (the machined inner incline) of the needle simply began to slip above the skin. As the collection tubes are vacuum tubes, they would thus be sucking up air and not blood. That would have been the noise you heard. This is the most likely scenario. It is possible, but unlikely, that the needle's attachment to the syringe or tubing was defective or not tight enough but again, that's fairly unlikely. As for the "bubble", at the moment the needle began to slip out of the vein, blood would have infiltrated the surrounding subcutaneous tissue causing a hematoma, or small blood blister. This is why the phlebotomist put extra pressure on the site to avoid an expansion of the "bubble" and to wait for the blood to begin clotting. Usually we suggested ice and ibuprofen for pain and swelling if required. The bruising usually goes away in about a week and doesn't normally cause problems. But beyond a week, or if the pain is severe and not abating within 24 hours you'll probably want to check with your doctor.
Hi Curious, The values you list for creatinine are not what we normally see. The normal range for creatinine is around 0.6 to 1.2, so the numbers you list don't make sense. If your creatinine levels were truly 40 to 60, you'd be in serious trouble with your kidneys. Now, you might be referring to the GFR or Glomerular Filtration Rate. This is a specialized test, and my experience with it is limited to none. I did do a Google search for you, and it looks like a physician would have to interpret your results, if in fact it was a GFR. Sorry I couldn't be more helpful.
Hi Justin. Go ahead and ask away. I'll do my best.
Hi thanks for your question, Quantitative analysis, or "How much"" of a substance, is usually done on blood samples in a regular laboratory. Forensic labs may be able to quantify other samples but I don't know if that includes hair. You could Google a forensic lab or your local coroners office for more info if you like.
Hi thank you for your question. This sounds like the patient may have an underlying condition that is contributing to falsely low WBC and platelet levels. Since I am not a physician I really couldn't say what those conditions are. There are ways to separate cells in the blood outside of the body. A process called "phoresis" is one I've heard of. But for a very good answer to your question call a local hospital, ask for the lab, then ask for a "Lab Tech". They could help you with this question better than I.
Hi Peter, thanks for your question. I can state categorically that I have no expertise regarding this question. I highly recommend you speak with a physician and/or paramedic. Best of luck on your novel.
Hi Ryab, Well, to be honest, it could be a problem. We had a gentleman in my military class that would sweat profusely and faint during the "first trials". He eventually was pulled from the class and reassigned. It's possible on the civilian side you could ask for counseling, but I'm guessing at best. To my knowledge, most lab techs have to be phlebotomy certified. Check with your program to see what your options are. Good luck in your endeavors!
Hi Mary Morgan, I don't recall any such requirement in either my military training or my civilian courses. But it is possible that each region has its own protocols. Best to check with the classes in your area. Good luck to you!
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