CLINICAL LAB SCIENEC

270
ESSENTIALS OF CLINICAL LABORATORY SCIENCE
Table 11-2 Steps That Help to Eliminate Mistakes in Sample Collection
1. Assemble supplies and put them within easy reach. It is diffi cult to reach for needed supplies while holding the needle apparatus
with the needle in the vein. A related precaution is that one should be prepared for the patient to make a sudden move, or to
knock the supplies to the floor if the patient is combative or has any dementia.
2. Safety precautions include having alcohol swabs available for cleansing the skin, and ensuring that the needle is sterile. The
phlebotomist should have already determined that the tubes are properly selected for size and type and that they are not expired
Bar-coded stickers are usually available for affixing to the tubes. If a tube is found to be defective, there are usually additional
stickers that can be used if a tube has to be discarded, wasting a label.
3. Varbally prepare the patient for the procedure. If the patient is disoriented, it might be necessary to ask for help from a co-worker
or from a nurse or assistant who works with the patient.
4. Place the tourniquet according to the tension taught in the classroom. In addition, the tourniquet should not be left on the arm for
more than 30 seconds to 1 minute.
5. Palpate the vein to determine the suitability of the vein or to locate a vein that might not be visible.
6. Cleanse the arm with alcohol swabs, and allow the site to dry for a few seconds. Insert the needle with the bevel up (opening or
lumen will be visible).
7. Obtain correct tubes by using pre-selected ones suitable for procedures requested. Allow them to fi ll fully, as not doing so may
cause errors in dilution of anticoagulants if present, or the sample might not be suffi cient in volume.
8. Care for the puncture site by loosening the tourniquet after the last tube is collected, and placing a dry gauze sponge or cotton
ball over the puncture site. Apply slight pressure on the sponge and withdraw the needle quickly.
9. Maintain pressure on the puncture site for a short period of time. The patient may be able to apply pressure in most instances
while the tubes are being safely stored and the waste is discarded properly in the correct receptacles.
10. Remove all used materials for proper disposal. Ensure that no sharp objects are left that might injure the patient. Place wastes
in proper containers, e.g. needles in “sharps” container, and routine waste into trash receptacle. Ensure samples are secured
properly for transport to the laboratory or other area as applicable.
damage to the red blood cells, causing the plasma to be hemolyzed. If a red cell
count is being performed, the count may be artificially lowered due to destroyed
cells, so this is a consideration in collecting both whole blood samples and where
hemolysis will interfere with test results.
In the case of a patient with normal veins, a vacuum tube system—consisting
of a barrel and a needle set containing a double-needle that can be screwed
into the barrel—is used. While the needle is in the patient’s arm, tubes may be
exchanged as they fill until all required specimens are obtained. With this system,
it is more difficult to know if the needle is in a vein, since there is no flash
or quick appearance of blood in the hub of the needle as would be the case
when using a needle and syringe system. But with experience, a phlebotomist or
laboratory technical worker can often feel that the bevel point of the needle is
sufficiently into the vein.
Another modified system is used predominantly by many laboratories but is
more expensive than the previous systems described. It is the “butterfly” needle,
which can be screwed into a barrel as previously described, or the end of the tube
may have a needle similar to that of the needle that is screwed into the barrel. This
needle may be used to pierce the rubber caps of the tubes; the tubes can then be
allowed to fill. Use of the butterfly system may be helpful on extremely difficult
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