Syringe Information and Courses from MediaLab, Inc.

The T-prep technique is a simple pull preparation method, which produces one readable long slide for each drop of marrow used. It does not require much manual dexterity or practice to obtain usable smears. Since this method only produces one usable smear per drop and requires a moderate size drop of marrow, it is not a preferred technique for small samples. However, it is easy to learn and is frequently used by clinicians.To perform this procedure, a drop of bone marrow is placed in the center of a slide (cross bar) and a second slide (post) is placed over it; oriented so the combination looks like the letter t. The marrow is allowed to spread between the two slides while the slide that is on the top (post slide) is pulled across the bottom slide (cross bar). This produces one slide with the bone marrow smear on the top slide. The bone marrow smear should cover approximately 3-4 inches in length.This technique can be performed sequentially with a series of 5-6 slides in a row with a drop of marrow quickly placed on each slide. The bone marrow drops can originate directly from the aspirate syringe at the patient bedside or from a transfer pipitte, collecting sample from an anticoagulated bone marrow tube. Once the first smear is made, the slide that initially had the drop of marrow becomes the top (post) slide for the next prep. By reusing the bottom slide, which no longer has any sample on it, one can minimize the amount of workspace required at bedside as well as reduce material wastage. Because the bone marrow is allowed to spread between two slide surfaces before the prep is pulled/smeared, any spicules present will be spread in a monolayer permitting good cellular identification. However, since only a limited number of smears are usually made, it is less useful for certain leukemia patients where many slides are required for special stains in addition to the normal morphology smears.

When the technologist accompanies the clinician to assist with the bone marrow aspiration procedure to make smears at the bedside, it is necessary to understand the role of the clinician and the technologist.The clinician is responsible for patient positioning and sterile preparation, pain control, and performing the aspirate and biopsy. The clinician often hands off sample syringes to the technologist, once collected. The clinicians are responsible for providing the procedure kit and fixative for the biopsy, all labels, and obtaining the requisitions and a copy of the clinical history for the hematopathologist. The technologist will set up a mini workspace near the bedside where the samples are split into the required tubes. Smears are then prepared from the aspirate as well as biopsy touchpreps before the biopsy is placed in fixative. In this setting the technologist will usually deliver the samples and requisitions to pathology and continue the processing procedure.The kit the technologist brings to the bedside usually contains mini petri dishes, coverslips, slides, microcapilary tubes or Pasteur pipettes, micro-pipette bulb and the various evacuated blood collection tubes and media flasks required for the standard bone marrow draw.Most institutions will have a standard draw and testing protocol designed to ensure that enough sample is obtained to cover all of the usual testing requirements. An example would be a three-syringe-draw with the first two syringes containing no anticoagulant and the third syringe rinsed with preservative-free heparin. The first dry pull would be split between a green and a purple top evacuated blood collection tube and would be used for morphology (EDTA) and flow cytometry and cytogenetics (green) if needed. The second dry pull is split into two additional purple top tubes plus a green top tube and would be used for molecular assays such as SNP array, Flt-3, JAK2, MPL mutation, etc. The final heparinized syringe could be used for other treatment protocol requirements or to provide sample for additional assays.

The marrow aspiration is usually performed before a biopsy is done. A syringe is attached to the needle, the plunger is pulled and 1.0-1.5 ml. of marrow particles and blood from marrow sinuses is withdrawn. If additional bone marrow samples are needed, a separate syringe must be used each time. If more than 2 cc. per syringe is taken out, the blood to marrow ratio will be too high and the preparations will not accurately reflect the marrow contents. As the marrow is aspirated into the syringe the patient will feel some pain and pressure even though local anesthetic has been administered.

The sample in the first syringe is quickly delivered into a watchglass or onto a slide. After the technologist verifies the presence of white-gray marrow particles in the sample, push smears and/or coverslip smears from this unanticoagulated sample are made immediately. All films should be rapidly air dried. The appearance of fat as irregular holes in the films also give the assurance that marrow and not just blood has been obtained. This type of smear is referred to as a direct smear and is usually used to evaluate morphology. Although some evaluation of cellularity and M:E ratio is possible, particle smears or biopsy sections provide a more accurate representation of these factors.

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.

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.

Butterfly needles may be used with a syringe or a holder and vacuum collection tube system. They are usually 21, 23, or 25 gauge.

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.

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.

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.

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.

The syringe and needle combination should be the last equipment option that is considered; it is not as safe a choice as the self-contained blood collection systems because it involves more manipulation. However, the phlebotomist may choose to use a syringe to prevent vein collapse if the phlebotomist thinks that the vein is too fragile to withstand the pressure exerted by the vacuum as it pulls blood into the collection tube. A transfer device aids in the safe transfer of blood from the syringe into blood collection tubes. During blood transfer, do not manually push plunger as this may cause hemolysis of the specimen.

Equipment: To successfully enter a hand vein, the phlebotomist must choose equipment that will allow needle entry at a very small angle. A winged device with a small gauged needle of 3/4 inch length is most often used to obtain blood from a hand vein. A syringe is usually attached to the end of the tubing of this device. By using a syringe, the phlebotomist can control the amount of pressure on the vein and avoid vein collapse. Evacuated tubes may collapse a vein by exerting too much pressure on the delicate vein. If available, smaller tubes containing less vacuum may be used.Insertion angle: The angle at which the needle is inserted into a hand vein is smaller compared to the angle of needle insertion into veins of the antecubital area. When drawing from a hand, the needle should be inserted into the vein at approximately a 15 degree angle to allow easier access of the surface hand veins. By inserting the needle at this angle, the risk of the needle going "through" the vein and puncturing the bony structures underneath are reduced.