What is the appropriate technique for transferring blood to an evacuated tube?
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Randomized Controlled Trial Show
Femoral phlebotomy: the vacuum tube method is preferable over needle syringeKeith Lafferty et al. J Emerg Med. 2006 Jul. AbstractA syringe needle (SN) is commonly used to obtain blood specimens from the femoral vein. The vacuum tube (VT) method avoids the needle stick potential of the SN technique during transfer of blood from the syringe to the collection tubes. We compared the perceived safety, patient pain, and efficacy of SN and VT for femoral phlebotomy in a prospective trial. Of 64 patients entered, 38 (59%) had the VT technique and 26 (41%) had the SN technique. There was no significant difference in the success rate between VT and SN (100% vs. 95%, respectively). The VT method was somewhat faster than the SN method (104 +/- 109 vs. 181 +/- 149 s, respectively, p = 0.06). Complications were infrequent and not different between the groups. The mean patient pain score +/- SD on a 10-cm visual analog scale for the VT and SN techniques were 2.6 +/- 2.2 and 3.7 +/- 2.7, respectively (p < 0.001). Physicians subjectively rated the safety of the procedure higher for the VT method than for the SN method. Medical personnel should consider use of the VT method instead of the traditional SN technique for femoral phlebotomy. Similar articles
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Publication typesMeSH termsNCBI Bookshelf. A service of the National Library of Medicine, National Institutes of Health. WHO Guidelines on Drawing Blood: Best Practices in Phlebotomy. Geneva: World Health Organization; 2010. 3Blood-sampling systemsUsers of these guidelines should read Chapter 2 before reading the information given below. This chapter covers background information (Section 3.1), practical guidance (Section 3.2) and illustrations (Section 3.3) relevant to closed and open blood-sampling systems. Several blood-sampling systems are available for phlebotomy. The system most appropriate for the procedure should be chosen. Annex C provides detailed information on all the systems available for drawing blood, and outlines the advantages and disadvantages of each device. 3.1. Background information on blood-sampling systems3.1.1. Closed systemsClosed systems for blood sampling are preferable because they have proven to be safer than open systems (23). Needle and syringeThe use of a hypodermic needle and syringe is the most common means of blood sampling. Choice of gaugeIf the needle is too large for the vein for which it is intended, it will tear the vein and cause bleeding (haematoma); if the needle is too small, it will damage the blood cells during sampling, and laboratory tests that require whole blood cells, or haemoglobin and free plasma, will be invalid. Blood collection for transfusion requires a larger gauge than is used for blood drawing. Vacuum extraction systemsThe use of vacuum extraction tube systems as closed systems for blood collecting reduces the risk of direct exposure to blood and has made it easier to take multiple samples from a single venepuncture. Vacuum extraction systems are widely available in most well-resourced countries. These are recommended, but users should check their own country's recommendations. Although vacuum extraction systems are safe, training and skill is required for their use. Double-ended needles are available in several recommended gauge sizes. The end covered by a rubber cuff is screwed into the barrel (also known as the tube holder, evacuated tube needle holder or bulldog). A thread separates the two ends, and this is where the barrel is screwed into place. The barrel holds the sample collection tube in place and protects the phlebotomist from direct contact with blood. The sample tube is under vacuum. Once the needle is in the vein, the tube is pressed on to the needle and the blood is drawn automatically into the sample tube by vacuum until the required amount is collected. This system comes complete with needle, barrel and the laboratory sample tubes with appropriately coloured tops for different types of samples. Tubes for adult and paediatric specimens are available. Discard the barrel and syringe as a single entity where possible. If there is a need to reuse the barrel, use a one-hand scoop technique (Annex G) to cover the sharp end of the needle and thus to safely remove the needle from the barrel. Alternately, use a sharps container with a needle removal hold, again employing a one-handed technique. Some systems have a mechanism that can be activated once the needle has been used; the mechanism retracts the used needle into the barrel and snaps it shut. Others have a quick-release mechanism to dislodge the used needle into the sharps container. Vacuum systems may also be used with a winged butterfly needle and luer-lock connectors. Winged butterfly needles are also available with safety-engineered devices. The sharps container must be within arm's reach and clearly visible, to ensure safe disposal of sharps. 3.1.2. Open systemsOpen systems include hypodermic needle and syringes, as well as winged steel needles attached to a syringe. 3.2. Practical guidance on blood-sampling systems3.2.1. Needle and syringeTo use a needle and syringe system:
3.2.2. Choice of gaugeChoose the gauge of hypodermic needle that fits comfortably into the most prominent vein with little discomfort (Table 3.1). Table 3.1Recommended needle gauge, length and device for routine injection and phlebotomy procedures for different age groups. 3.3. Illustrations for blood-sampling systems Figure 3.1Blood-sampling systemsCopyright © 2010, World Health Organization. All rights reserved. Publications of the World Health Organization can be obtained from WHO Press, World Health Organization, 20 Avenue Appia, 1211 Geneva 27, Switzerland (tel.: +41 22 791 3264; fax: +41 22 791 4857; e-mail: tni.ohw@sredrokoob). Requests for permission to reproduce or translate WHO publications – whether for sale or for noncommercial distribution – should be addressed to WHO Press, at the above address (fax: +41 22 791 4806; e-mail: tni.ohw@snoissimrep). Bookshelf ID: NBK138666 What is the evacuated tube method?The evacuated tube system is the most commonly used means of collecting specimens. This system is preferable to the needle and syringe since it allows the blood to pass directly from the vein to the evacuated tube.
How is blood transferred to a test tube?Attach the syringe to a blood transfer device by twisting the needle tip into the hub of the device. Push a vacuum blood collection tube into the holder of the transfer device, and let the tube fill to the appropriate level.
What is the order of draw of blood into the evacuated tube?Standard order of draw: BLOOD CULTURES, royal blue, red, light blue, SST (Gold), green, tan, yellow, pink, pearl, lavender. If a coag tube (light blue) is the only tube or the first tube to be drawn, a 5 mL discard tube must be drawn first. or incubation conditions. incubation may be required.
What are the four phlebotomy techniques?Draw Blood-. Capillary method-. Venipuncture-. Fill up sample tubes-. Complete procedure-. Prepare for transportation of samples-. |
