(Editor's note: This article originally appeared in Phlebotomy Today-STAT!, a free e-newsletter from the Center for Phlebotomy Education Inc. Reprinted with permission. For more information, visit http://www.phlebotomy.com/.)

We thought this month would be a good time to investigate some of the more notorious phlebotomy myths and misinformation haunting healthcare facilities around the globe. Our goal: to exterminate the ill-conceived notions and bad techniques listed below that have the power to harm you or your patients.

1. All veins are fair game. According to CLSI, the preferred venipuncture site is the antecubital fossa. Of which, the safer median and cephalic veins should be ruled out first before selecting the basilic vein due to its close proximity to the median nerve and brachial artery. When veins in the antecubital area of both arms are unavailable, veins on the back of the hand and thumb-side of the wrist are acceptable alternatives. Above all, phlebotomists should be aware of the potential for injury associated with each vein and prioritize site selection accordingly. Other sites, such as veins of the lower extremities, should not be used without physician permission because of the risk of serious complications.

2. Draws on the side of a mastectomy are OK if the patient gives permission. Because a patient may not fully comprehend the potential for injury associated with draws to the same side of a prior mastectomy, it could be successfully argued the patient cannot give informed consent. In cases of a bilateral mastectomy, always consult a physician before collecting the sample. This includes fingersticks, too, as any break in the skin on the affected side can lead to complications from lymphostasis.

3. Patients should be allowed to pick the device with which you draw their blood. You wouldn't tell your dentist which drill bit to use, so why should patients be allowed to select the device you should use for their venipuncture? You're the phlebotomist. As such, you have infinitely more training and/or experience from which to draw in order for the procedure to be successful and safe. Although patients often suggest, even demand, certain devices such as butterfly sets, you get the final say. Do you really want to subject yourself to the increased risk of an accidental needlestick that comes with butterfly use just so that the patient gets his/her way? Sure, it's a customer service issue, but your safety should not take a lower priority, especially when another device will be just as successful in your hands, or even more so. Be diplomatic, be cordial, but above all, don't allow patients to compromise your safety.

4. Patients should be allowed to select the site from which you draw their blood. This myth is only true if the patient knows and applies what the CLSI standards say about site and vein selection. (See myth #1.) Because most don't, you should have the final say. Even if she selects a vein in the antecubital area, drawing from it may go against the standards if it's the basilic vein and you haven't done a thorough survey of all acceptable veins in both arms. That's because most nerve injuries caused during venipuncture occur during attempts to access the basilic vein. Should the patient select that vein, it's against the standards not to exhaust all other antecubital options first.

5. Refrigeration is the preferred method of preserving blood prior to centrifugation. While refrigeration might be best for fish and vegetables, that's not always the case for blood samples--especially if they're to be tested for potassium. That's because red blood cells are rich in potassium. In fact, the concentration of potassium in red cells is up to 25 times that of serum or plasma. At refrigerated temperatures, potassium rushes out of the cells and contributes significant quantities to that in the serum or plasma to be tested. The result: patients can be misdiagnosed and improperly medicated. The solution: refrigerate samples to be tested for potassium only after they have been centrifuged and the serum or plasma to be tested has been separated by a gel barrier or by transferring an aliquot into an appropriately labeled transfer tube.

6. A bandage is an acceptable substitute to applying direct pressure to a puncture site. Not true. According to the CLSI standards, those who draw blood samples must make sure stasis is complete before bandaging. That means being assured not only has the puncture to the skin sealed, but the puncture to the vein as well. This requires patience and observation. Instead of rushing a bandage onto the site and hoping it applies enough pressure to prevent bleeding (it won't), remove the gauze and observe the site for 10-15 seconds. Any sign of bleeding or hematoma formation demands additional pressure.

7. Having the patient pump his fist is the best way to find hard-to-locate veins. While this may be true for donors, when you're drawing blood from patients this technique can dramatically alter test results. In fact, some studies have shown pumping the fist can double the potassium level to be reported to the physician. Instead, have the patient clench and hold the fist, but only if necessary. While clenching and holding hasn't been found to increase potassium levels in the same arm, pumping certainly will.

8. Anchoring from above and below the venipuncture site is the recommended way to prevent a vein from rolling. Using this so-called "C-hold" or "windows" technique might do a fine job of anchoring the veins and stretching the skin, but it also does a fine job of increasing your risk of an accidental needlestick, too. When your finger is placed above the intended puncture site, it's in harm's way should the patient jump or should you be bumped from behind at the wrong moment. If you've used this technique for years without a needlestick and feel you've mastered the technique safely, you're long overdue for an exposure.

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