Stick Information and Courses from MediaLab, Inc.

Perform quality control procedures. Use a fresh, well-mixed uncentrifuged urine. Hold the reagent strip by the opposite end from the test areas and dip the stick into the specimen so that all test areas are immersed in the specimen. Remove the stick immediately. Prolonged immersion in the sample may wash out the test reagents. Hold strip in a horizontal position and run the edge of the strip against the rim of the urine container or touch the long edge of the strip to absorbent toweling to remove excess urine (do not blot the strip). Maintain the strip in a horizontal position to prevent mixing of reagent chemicals. Observe the reagent pads at the specified time periods. Color changes that occur after the stated maximum read time are not valid. Hold the strip close to the chart and compare the colors to read the results. A good light source facilitates accurate reading.

A routine reagent strip protein method, based on the principle of "protein error of indicators," produces a visible colorimetric reaction that is capable of detecting most instances of proteinuria.Traditionally, laboratories have used sulfosalicylic acid (SSA) to confirm all positive protein reagent strip results, but this practice is not as common in today's laboratories. SSA is a precipitation method that reacts with all forms of protein. However, any substance that is precipitated by acid will produce false-positive SSA results. This includes radiographic dyes, cephalosporins, penicillins, and sulfonamides. SSA may be used as a secondary protein detection method if the urine is highly alkaline (pH of 9.0 or greater) which would overwhelm the buffering capacity of the reagent on the protein reagent stick. SSA may also be used as an alternative protein detection method if the urine is highly colored so that the colorimetric reaction is masked on the reagent strip.

In summation, we have covered the following sequence of events which comprise primary hemostasis. The process begins with damage to a vessel wall, as blood flows outside the vasculature. The body responds with vasoconstriction, decreasing blood flow to the affected area. Platelets begin sticking to the damaged vessel walls. As the platelets stick, they release chemicals which signal other platelets to respond. As other platelets arrive, they begin sticking to one another, clumping together, forming a plug to fill in the breach. This plug, while strong, is a temporary fix, and must be reinforced with fibrin strands to effectively fill the breach during the vessel repair process. Construction of the fibrin strands occurs during secondary hemostasis, our next topic to be covered.

Particle smears are also made from the unanticoagulated sample. The bone marrow particles are removed from the watchglass and placed on a coverslip. One of the following items: Pasteur pipet, capillary tube or broken end of a wooden applicator stick, may be used to transfer the particles. A second coverslip is placed over the first and the particles are crushed between the coverslips as they are pulled apart. Some practice is needed to perfect this technique. As mentioned previously, this type of preparation provides a more accurate assessment of marrow architecture and cellularity than the direct smear. Morphological detail is preserved on well made slides. The remaining sample may be added to a tube containing EDTA anticoagulant and additional smears may be made if needed.

The amount of blood needed to cause HBV infection is very small.One milliliter of blood contains up to 100 million infectious particles.Of the persons exposed to HBV by needle stick, 30% will get the infection.

Marcie Moore was a phlebotomist at a community hospital in Atlanta. It was her week to collect the pediatric unit and she was on her way to the room of a newborn for which she had just received orders to draw a STAT BMP (chem-7) and bilirubin. After informing the mother of the baby about the test she needed to perform, Marcie set up to perform a heel stick on the baby. Marcie chose a site on the outer edge of the heel on the bottom of the baby’s foot ( the correct area for a heel stick) and made a small incision with a Tenderfoot lancet after cleaning the site well with alcohol.She immediately began collecting the blood in the correct tube for the BMP and bilirubin. Blood flow was not strong so Marcie squeezed the baby’s foot a little to help the blood come out faster – the newborn was screaming and Marcie could tell it was making the mother uncomfortable. She wanted to hurry and get done so the mother could hold the baby.After the chemistry tech ran the blood tests on the tube, she informed Marcie that the newborn had a panic potassium level which did not coincide with the previous blood work on the newborn. Also the chemistry instrument could not perform the bilirubin due to hemolysis. Marcie was asked to recollect the specimen.

During a finger stick procedure it is important that the lancet be positioned on the finger so that the incision is perpendicular to the fingerprint. This allows a larger amount of blood to flow. It is also important to wipe away the first drop of blood that emerges form the incision with clean gauze, since it may contain tissue fluids that can cause incorrect test results. The first drop of blood may also contain traces of alcohol remaining from the cleaning step. Alcohol may break up or hemolyze blood cells, causing incorrect results.Relevant topics:Finger-stick collections, Finger-stick: site preparation, Finger-stick: puncture, Wipe away the first drop, Finger-stick specimen collection

A phlebotomist from the laboratory at Midtown Memorial Hospital was working evening shift. Her shift ended at 11 PM and it was 10:30 PM. She suddenly got orders for a STAT blood culture on the second floor. The order specified blood culture times two, 30 minutes apart. The phlebotomist went to the patient’s room and decided to collect both blood cultures at the same time form the same site so she would be able to leave on time without having to come back in thirty minutes to collect the second set. She also wanted to “save” the patient from an extra stick. While the phlebotomist was preparing for the collection, she realized she didn’t have any Betadine on her tray, and decided she would just clean the site twice with alcohol. She finished the blood culture collections and was able to leave by 11 PM.

Lancets are used for difficult venipunctures, including pediatric draws. They are used for finger sticks with microcapillary collections.

If possible, use the fourth (ring) finger or the middle finger.Many patients prefer that you use fingers on their nondominant hand. Choose a puncture site near the right or left edge of the finger tip.Clean the site as you would for routine venipuncture.

A finger-stick collection is performed by piercing the fingertip with a safety Lancet, which controls the depth of incision, and collecting capillary blood. The BD Microtainer™ Brand Safety Flow Lancet is shown here.Finger-sticks should not be performed on children under one year of age.

Wipe away the first drop of blood using gauze to remove tissue fluid contamination.