| Discussion Hemolysis can easily be caused by improper phlebotomy techniques. Hemolysis occurs when RBCs are broken up and hemoglobin is released into the plasma, causing it to become pink rather than its natural straw color. Hemolysis can occur by using too small a needle, pulling a syringe plunger too rapidly, expelling blood vigorously into a tube, or shaking a tube of blood too hard. Hemolysis can cause falsely increased potassium, magnesium, iron, and ammonia levels, and other aberrant lab results.In this case, Marcie did not properly wipe the site with gauze after cleaning it with alcohol, and alcohol contacting the blood could have caused RBCs to break up or hemolyze. Marcie also squeezed the baby’s foot too hard, causing hemolysis.Relevant topics:Site selection and preparation, Heelstick: Puncture, Hemolysis, Causes of hemolysis | View Page |
| What could have caused the clotting? | View Page |
| Discussion When drawing blood into evacuated tubes, it is best to draw the tiger top and red top tubes first, so that tissue fluids and fragments that cause blood to clot are retained in a tube which will clot anyway. Such tissue fluids and fragments are most likely to be present in the first tube to be drawn. If tissue fluids and fragments are present in a light blue top tube used for coagulation tests, they will interfere with the test results. However, recent studies have shown that accurate coagulation results may be obtained from the first tube drawn. It is nevertheless recommended that tiger and red top tubes be drawn first when using the evacuated tube system.If blood had been drawn first into a syringe, the order in which the blood is expelled from the syringe into the tubes would be different. Since no anticoagulant is present in the syringe the blood must first be expelled into the light blue top tube, then the lavender top tube, and finally the tiger top tube. This is so that the blood is promptly mixed with the anticoagulants present within the light blue and lavender top tubes before clotting begins. Clots in a lavender top tube are likely to cause a falsely low platelet count.Relevant topics:Lavender top tubes, Light blue top tubes | View Page |
| Single draw needles Single draw needles are of the type that fit on a syringe, and can be used only to fill the syringe to which they are connected.
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| Syringes with built-in safety devices Syringes are used for injections, as well as to collect blood.
There a various syringes with built-in safety features.One example is the Monoject™ (Sherwood Services AG), Safety Syringe, shown here. | View Page |
| Syringes with built-in safety devices contd. After use, a safety shield is slid over the needle, and locked into place.
The safety syringe with the shield locked in place is shown here. | View Page |
| Blood transfer device A blood transfer device allows the transfer of blood from a syringe into a blood collection tube or a blood culture bottle.
The BD™ blood transfer device is shown here.
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| Butterfly needles continued Butterfly needles may be used with a syringe or a holder and vacuum collection tube system.
They are usually 21, 23, or 25 gauge.
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| Syringe - Syringe blood collections Syringes may be used to collect blood from patients having small or delicate veins that might be collapsed by the vacuum of the evacuated tube system.Syringes may also be used to collect blood culture specimens. | View Page |
| Syringe - Syringe blood collections continued Syringes may be used in two ways:Syringes may be used in two ways:A syringe may be attached to a butterfly or winged infusion set.
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| Syringe - Transferring blood to collection tubes After collecting the blood specimen into a syringe, properly activate the appropriate safety device, and dispose of the needle in a sharps container.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.
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| Syringe - Transferring blood to collection tubes contd It is important to transfer the blood to appropriate tubes immediately because a syringe contains no anticoagulant, and the transfer must be complete before blood starts to clot.Do not push the plunger while transferring blood into a collection tube.
This may cause hemolysis, ruining the specimen. | View Page |
| Butterfly needle - Butterfly needle collections continued Butterfly needles come attached to a small tube which may be connected to:An evacuated tube holder, orA syringe. | View Page |
| Collection methods Blood for culture can be collected in several ways:Standard needle attached to a syringe.Butterfly needle attached to a syringe.Blood culture bottle attached directly to tube holder (not generally recommended).Follow you own facilities’ procedure for blood culture collection. | View Page |
| Activate needle safety device After collecting the blood, activate the needle safety device according to manufacturer’s instructions, and place it in a sharps disposal container.
If blood was collected into a syringe, insert the syringe tip into the hub of a blood transfer device, and rotate the syringe clockwise to secure it to the device.
Push the blood culture bottle into the holder of the transfer device, and draw the appropriate volume of blood into the blood culture bottles. | View Page |
| Causes of hemolysis Hemolysis can be caused by: Shaking the tube too hard.Using a needle that is too small.Pulling back too hard on a syringe plunger.Pushing on a syringe plunger too hard when expelling blood into a collection device.
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| Causes of clotting Clotting can be caused by: Inadequate mixing of blood and anticoagulant within the collection tube.Delay in expelling blood within a syringe (which contains no anticoagulant), into a collection tube with anticoagulant. | View Page |