NCCT Phlebotomy Exam (Orders and Equipment)

Which of the following information is required on a requisition form before a phlebotomist can send a patient's sample to the lab? (Select the three (3) correct answers.) A. doctor's name B. patient's social security number C. patient's date of birth D. type of test E. patient's address

doctor's name, patient's date of birth, type of test Rationale Test requisitions must contain certain information as they become part of the patient's medical record. The ordering doctor's name is needed to ensure the test results are sent to the correct physician and facility. The patient's date of birth is used to confirm the right person is being drawn. The type of test tells the lab which analysis to perform. Social security numbers and the patient's address are not needed on a test requisition.

Sodium citrate tubes have a line or an arrow somewhere on the tube. The purpose of this mark is to A. indicate sodium citrate levels in the tube. B. ensure the correct blood to additive ratio. C. allow the phlebotomist to under fill the tube and adjust blood volume D. indicate the correct placement of the tube in the adapter.

ensure the correct blood to additive ratio. Rationale For accurate results in coagulation testing, the light blue top tubes must be filled to the line marked on the tube. This insures a proper 9 parts of blood to 1 part of anticoagulant (sodium citrate) ratio. The line does not indicate the level of sodium citrate in the tube, allow the phlebotomist to adjust the blood level in the tube or indicate the placement of the tube in the holder.

Which of the following anticoagulant tubes also contains an antiglycolytic agent? A. serum separator tube B. EDTA tube C. sodium citrate tube D. potassium oxalate tube

potassium oxalate tube Rationale In addition to the anticoagulant potassium oxalate, the gray topped tube contains sodium fluoride which is an antiglycolytic. The sodium fluoride delays the metabolism of glucose by the red and white blood cells and platelets, helping to stabilize the glucose level until it can be analyzed. Lavender tops contain EDTA, Blue tops contain sodium citrate and gold tops contain a gel to separate the serum from the cells after clotting has taken place.

Which of the following are the additives found in a gray-top tube and what are they able to do? (Select the three (3) correct answers.) A. prevent coagulation B. inhibit thrombin C. inhibit calcium D. prevent glycolysis E. inhibit fibrin

prevent coagulation, inhibit calcium, prevent glycolysis Rationale There are two additives in a gray top ETS tube - potassium oxalate which prevents coagulation of the blood by inhibiting calcium and sodium fluoride which prevents the glycolysis of glucose to lactic acid. Heparin is used as the anticoagulant in green top tubes and acts by inhibiting the formation of thrombin. Fibrin is the end product of the coagulation process resulting in a clot.

Which of the following tubes contains ethylenediamine tetraacetic acid (EDTA)? A. yellow B. royal blue C. gray D. red

royal blue Rationale The royal blue tube contains EDTA as an anticoagulant. The yellow is a sterile tube containing SPS and liquid culture media. A gray tube has potassium oxalate and sodium fluoride. The red tube is for serum and does not contain an anticoagulant.

Which of the following is the additive/anticoagulant in the light blue top tube? A. EDTA B. sodium citrate C. lithium heparin D. potassium oxalate

sodium citrate Rationale Blood collection tubes are color coded to indicate their chemical contents. The light blue top contains sodium citrate. The lavender top contains EDTA, the green heparin and the gray potassium oxalate.

A patient has orders for a coagulation study and is on coumadin. Which of the following is the proper additive to be added to the blood in order to complete the coagulation study? A. EDTA B. sodium citrate C. heparin D. potassium oxalate

sodium citrate Rationale Sodium citrate (light blue tube) is used as an anticoagulant for coagulation studies. EDTA (lavender top) is used for hematology testing, heparin (green top) and potassium oxalate (gray top) for chemistry analyses.

A phlebotomist collects lavender, red (plastic), green, and light blue stopper tubes from a patient. Which of the following lists the additives of these tubes in the correct order of draw? A. sterile (no-additive), sodium citrate, heparin, EDTA B. EDTA, clot activator, heparin, sodium citrate C. sodium citrate, clot activator, heparin, EDTA D. EDTA, sterile (no-additive), sodium citrate, heparin

sodium citrate, clot activator, heparin, EDTA Rationale Blood collection tubes are color coded to indicate their chemical contents. The Clinical Laboratory Standards Institute (CLSI) defines the order of drawing these tubes to prevent carryover of the contents from one tube to the next. A small amount of the chemical may be retained on the inner needle or rubber sleeve of the ETS system and contaminate the next tube thereby affecting patient results. The order is sterile (blood cultures), sodium citrate (blue), serum ( red or gold with or without clot activator or gel separator), heparin (green), EDTA (purple or pink), sodium fluoride & potassium oxalate (gray).

A patient presents with multiple skin tears and very thin skin appearance. What type of material should the phlebotomist use following the blood draw? A. 2 x 2 gauze and paper tape B. 2 x 2 gauze and Band-Aid C. 2 x 2 gauze and roll up gauze D. 2 x 2 gauze and Coban

2 x 2 gauze and Coban Rationale Patients with multiple tears or fragile skin are not candidates for the usual bandages applied after venipuncture procedures. Paper tape or bandaids may injure the skin when removed and leave the area open to infection or bleeding. All venipuncture wounds should be covered with 2 x 2 gauze after the phlebotomist has checked that bleeding has stopped. In this case, Coban would be the best bandage to use. It is self adhesive and does not stick to the skin. Roll up gauze would not apply enough pressure to the site.

The physician has ordered a blood culture collection for a patient. Which of the following antiseptic solutions should the phlebotomist use for cleansing the site? A. antibacterial soap and water B. 70% isopropyl alcohol C. 2% hydrogen peroxide D. 2% benzalkonium chloride

2% benzalkonium chloride Rationale To minimize the risk of contamination by normal skin flora, sites for blood culture collection require a 30 - 60 second scrub to access the bacteria beneath the dead skin cells in the area. Friction and letting the site air dry are important factors. Although not appropriate for children under 2 years of age, 2% benzalkonium chloride can be used as an antiseptic to clean blood culture venipuncture sites. Isopropyl alcohol may be used but requires a longer scrub with at least two pads. Isopropyl alcohol is used to clean the tops of the cultures bottles before inoculation with blood. Hydrogen peroxide or antibacterial soap and water are not considered effective for blood culture site cleansing. Preparations of iodine or betadine are not commonly used as they may provoke allergic reactions. Whichever antiseptic is used, it is important to allow the area to air dry and not to retouch the site before performing the venipuncture.

The physician has ordered a PKU test on a newborn. Which of the following should the depth of penetration be? A. 1.5 mm B. 2.0 mm C. 2.5 mm D. 3.0 mm

2.0 mm Rationale The lancet used for a heel puncture on a full term infant should not penetrate beyond 2.0 mm (1.8mm for a premature infant). If the blade were to go deeper, the heel bone (calcaneus) might be pierced leaving the child susceptible to a serious bone infection known as osteomyelitis. Insufficient depth will not yield adequate blood flow.

The appropriate needle gauge to use for most venipuncture collections is A. 15. B. 18. C. 21 .D. 23.

21. Rationale A range of needle gauges (sizes) is needed to accommodate the different sizes of veins and tissues the phlebotomist may incur. The smaller the number, the larger the needle. Typically used are 21, 22 and 23 with the 21 being most appropriate and commonly used. A needle smaller than 23 might hemolyse the red blood cells and the sample could not be used for testing. A 15 would be too large and could cause injury to the patient. 18 gauge needles are used for blood transfusion and IV fluid administration. 25 gauge needles are used for IM injection.

Physician orders an ESR and PT, PTT on an 11-month-old infant. Which of the following is the most appropriate equipment for this blood collection? A. Heel lancet and two microcollection tubes. B. Heel lancet and three microcollection tubes. C. 23G butterfly needle and two pediatric evacuated tubes. D. 23G butterfly needle and three pediatric evacuated tubes.

23G butterfly needle and three pediatric evacuated tubes. Rationale A 23 G butterfly needle would be used with three pediatric evacuated tubes in this case as one would need one "discard" tube to fill the line of the butterfly with blood, one blue (PT, PTT) and one lavender (ESR). If a discard is not used, the blue tube will not be filled correctly, giving incorrect patient results. A heel lancet would not be used as there are no blue (sodium citrate) microtainers. Coagulation tests (PT, PTT) are not done from dermal punctures. Also, the ESR requires 1 ml of whole EDTA blood which is too large a volume to be collected from a heel stick.

A 78-year-old patient with fragile veins presents to the lab for recurring PT/PTT testing. Which of the following equipment should the phlebotomist use? A. 23g vacutainer needle, adapter, lavender tube B. 23g vacutainer needle, adapter, light blue tube C. 23g butterfly needle, light blue tube D. 23g butterfly needle, lavender tube

23g butterfly needle, light blue tube Rationale The light blue tube (sodium citrate) is used for PT/PTT testing. If a patient has fragile veins the vacutainer system is contraindicated as the vacuum might put too much pressure on the vessel, causing it to collapse or the blood to become hemolysed. Therefore, a 23 g butterfly may be used with a light blue tube as long as a discard tube that allows the butterfly tubing to be filled before attaching the light blue tube is used. Failure to fill the tubing with blood will cause incorrect filling of the light blue tube and incorrect patient results. Light blue tubes (sodium citrate) require a ratio of 1 part citrate to 9 parts of blood for accurate results. Lavender tubes are typically used for Hematology tests such as the CBC (Complete Blood Count).

A phlebotomist has just completed a successful venipuncture and is about to apply the bandage. The patient tells the phlebotomist that he suffers from contact dermatitis. The phlebotomist should apply a A. standard bandage. B. 2x2 gauze pad and paper tape. C. 2x2 gauze pad and wrap with Coban. D. 2x2 gauze pad with nylon tape.

2x2 gauze pad and wrap with Coban. Rationale It is the phlebotomist's responsibility to assure bleeding has stopped at the venipuncture site before applying an appropriate dressing and releasing the patient. Typically, an adhesive bandage over a 2x2 gauze pad it used. In this case, since the patient suffers from contact dermatitis, a better choice would be the 2x2 gauze pad wrapped with coban as this is less likely to aggravate the skin. Any kind of tape including paper or nylon may cause a skin reaction.

Which of the following is made of a flesh colored permeable polyester fabric and acts as a compression bandage? A. gauze B. Band Aides C. Ace bandages D. Coban

Coban Rationale Coban is a flesh colored, water-vapor permeable, non-woven polyester fabric made of polyester urethane. The fabric is coated with a self-adherent substance that gives the bandage the ability to stick to itself but not to skin or clothing. It stays in place once applied. Coban can maintain limited but significant levels of bandage pressure. It is primarily used in patients on anticoagulant therapy, those with bleeding disorders or fragile skin. Gauze, bandaids or ace bandages do not have these properties.

As the phlebotomist removes the cap from the needle before a venipuncture, she notices the needle is bent. Which of the following should the phlebotomist do? A. File a report and return the needle to the manufacturer. B. Inform the supervisor. C. Recap the bent needle and put it aside. D. Discard the needle and obtain a new one.

Discard the needle and obtain a new one. Rationale As with any manufactured device, a certain number of items are expected to have defects. The vendor's good quality control program should find and prevent these from getting out into the market. However, it is the phlebotomist's responsibility to assure the equipment to be used for blood collection is acceptable before use on a patient. This is why the needle is inspected after removing the cap for any defect including straightness, burrs and an open lumen. Needles are never recapped. The needle and the holder, syringe or butterfly to which it is attached should be placed in a sharps container. Documenting the occurrence is always a good idea and if there are more instances within a certain lot or shipment, the manufacturer should also be notified.

Which of the following additives prevents coagulation by inactivating calcium? (Select the three (3) correct answers.) A. EDTA B. lithium heparin C. sodium citrate D. sodium fluoride E. oxalate

EDTA, sodium citrate, oxalate Rationale Anticoagulants prevent blood from clotting by several chemical mechanisms. Calcium is necessary along with many clotting factors for coagulation to occur. Inactivation of calcium interrupts the "coagulation cascade" and prevents fibrinogen from becoming fibrin (clot). Oxalate forms insoluble calcium salts, while EDTA and sodium citrate chelate or bind this element. Lithium heparin prevents clot formation by inhibiting thrombin. Sodium fluoride is an antiglycolytic used to stabilize the glucose level in a blood sample.

The draw is finished and afterward the patient continues to bleed. The phlebotomist asks the patient to hold pressure, but the patient indicates difficulty doing so. Which of the following should the phlebotomist do next? A. Ask the patient to hold pressure briefly until the tubes are stored. B. Ask the patient to elevate the affected arm to stop bleeding. C. Place a cotton ball over the area until the tubes are stored and return to hold pressure. D. Hold pressure for the patient until bleeding is controlled.

Hold pressure for the patient until bleeding is controlled. Rationale It is the phlebotomist's responsibility to assure the stoppage of bleeding after performing a venipuncture. All other activities should be postponed until this is achieved. Elevation of the arm or the placement of a cotton ball are not as effective as direct pressure. The use of cotton balls has been discouraged as the cotton fibers may stick to the platelet plug formed at the wound site. Dislodging the clot on removal of the bandage might reactivate bleeding.

Which of the following is likely to happen to the specimen if the phlebotomist does not invert a lavender top tube 8 to 10 times? A. Hemolysis will occur. B. Potassium will be released into the plasma. C. Microclots will form. D. Calcium will precipitate.

Microclots will form. Rationale Failing to adequately mix the blood in a lavender top (EDTA) with the anticoagulant may cause the formation of microclots and give inaccurate patient results. These tiny clots interfere with instrument operation, cause specimens to be redrawn and delay patient treatment. If they are not detected during the analysis, the inaccurate results may cause the patient to be incorrectly treated. Incorrect mixing does not cause hemolysis unless the specimen is forcefully shaken. If the red blood cells are ruptured (hemolyzed), potassium would be released into the plasma. EDTA acts to anticoagulate blood by binding calcium but it is not precipitated in the specimen.

After the phlebotomist puts on latex gloves and ties a non-latex tourniquet on the patient's arm, the patient indicates that he is highly allergic to latex. Which of the following is the phlebotomist's best course of action? A. Change to non-latex gloves and proceed with the same tourniquet. B. Change to non-latex gloves and use a new tourniquet C. Wash hands, change to non-latex gloves, and proceed with the same tourniquet. D. Wash hands, change to non-latex gloves and use a new tourniquet.

Wash hands, change to non-latex gloves and use a new tourniquet. Rationale Latex allergies can be life threatening. It is important to ascertain this information from the patient before initiating the procedure. In this case, the phlebotomist should remove the latex gloves, wash hands, change to latex free gloves and use a non latex tourniquet for the collection.

A patient on chemotherapy has presented for routine bloodwork. Due to the chemotherapy, the patient has small, weak, and frail veins. After a first failed attempt the phlebotomist prepares to draw again. Which of the following supplies should the phlebotomist choose? A. an ETS set B. a butterfly with a Luer adaptor and an ETS hub C. a 23 gauge butterfly with syringe D. a syringe set

a 23 gauge butterfly with syringe Rationale It is not uncommon for patients on various medical protocols including chemotherapy to develop venous access issues. In this case, using an ETS system might induce too much pressure on the vein either causing it to collapse or the blood to hemolyse. A butterfly with a luer adaptor would present the same issue. A syringe set allows the phlebotomist to control the pressure and might suffice depending on how much blood is to be collected. The butterfly with a small needle attached to a syringe allows for a lower angle of insertion and more control.

A patient receiving chemotherapy has come into the lab with an order that requires multiple tubes. After failing on the first attempt with a butterfly, the phlebotomist is preparing for a second attempt. Which of the following supplies should be chosen to reduce intravenous pressure and keep the vein from collapsing? A. a butterfly with a multisample adapter B. a vacutainer with a 23g needle C. a butterfly with a syringe D. a syringe with a 23g needle

a butterfly with a syringe Rationale Patients who have received chemotherapy treatments frequently have fragile veins. The use of vacuum tubes on these veins may apply too much pressure, causing them to collapse. A syringe and butterfly would offer more control and the prospect of a successful draw. A 23g needle is a good option in this case.

If an EDTA tube is under filled, the patient's results will likely come back with A. a falsely high blood cell count. B. hemoconcentration. C. hemolysis. D. a falsely low blood cell count.

a falsely low blood cell count. Rationale Underfilling the EDTA blood collection tube can lead to erroneously low blood cell counts and hematocrits, morphologic changes to RBCs, and alteration in cell staining. Excess EDTA can shrink red cells. Hemolysis or the rupture of red blood cells is unlikely in an underfilled tube unless it is shaken very hard or from a difficult draw. Hemoconcentration (the change in ratio of analytes to cells in plasma) can be caused by leaving the tourniquet on too long (more than 1 minute).

Which of the following is the primary function of sodium fluoride agent found in gray-stoppered tubes? A. antibiotic B. antiglycolytic C. anticoagulant D. antihemolytic

antiglycolytic Rationale The primary function of the sodium fluoride found in gray topped tubes is to act as an antiglycolytic which prevents the metabolism of glucose to lactic acid by the red blood cells in the specimen. If not prevented, glycolysis may decrease the level of glucose of as much as 10 mg/dl per hour leading to inaccurate patient results and possible medical mistreatment. The anticoagulant in the gray top is potassium oxalate which keeps the blood from clotting and makes the plasma available for testing after centrifugation. An antibiotic (used to treat bacterial infections) or an antihemolytic (an agent used to prevent hemolysis of red blood cells) are not included in vacuum blood collection tubes.

A phlebotomist collected a PT and an H&H on the dorsal side of the hand. The phlebotomist collected a citrate tube, then an EDTA tube, and inverted each tube 3-10 times after collecting. Once transferred to the lab, the PT specimen was rejected. The specimen was most likely rejected due to incorrect A. blood to additive ratio. B. tubes collected. C. order of draw. D. number of inversions.

blood to additive ratio. Rationale The phlebotomist collected the correct tubes for the tests ordered, citrate (blue) for the PT and EDTA (lavender) for the H&H. They were drawn in the correct order. The number of inversions was adequate to mix the blood well with the tube additives. The blue top may have not been adequately filled. For accurate coagulation testing there must be a ratio of nine parts of blood to one part of sodium citrate. Incorrect filing will result in rejection and a request for the specimen to be redrawn.

A phlebotomist reviews a doctor's order for a blood culture on a patient. While reviewing the patient's chart, the phlebotomist notices that the patient has a shellfish allergy. Which sterile solution should the phlebotomist use on this patient to avoid the potential for anaphylactic shock? A. 2% iodine B. Betadine C. Providone iodine D. chlorhexidine

chlorhexidine Rationale A patient with a shellfish allergy is sensitive to anything containing iodine. Therefore, 2% iodine, betadine or povidone solutions should not be used as an antiseptic for blood culture collection. The best choice would be chlorhexidine.

Which of the following is a proper antiseptic agent for drawing blood cultures? A. chlorhexidine gluconate B. isopropyl alcohol C. soap and water D. antibacterial gel

chlorhexidine gluconate Rationale To minimize the risk of contamination by normal skin flora, sites for blood culture collection require a 30 - 60 second scrub to access the bacteria beneath the dead skin cells in the area.Friction and letting the site air dry are important factors. Although not appropriate for infants under 2 months of age, chlorhexidene gluconate has become the antiseptic of choice. Isopropyl alcohol may be used but requires a longer scrub with at least two pads. Isopropyl alcohol is used to clean the tops of the cultures bottles before inoculation with blood. Soap and water or antibacterial gels would not afford the antisepsis needed to prevent contamination. Preparations of iodine or povidone are not commonly used as they may promote allergic reactions. Whichever antiseptic is used, it is important to allow the area to air dry and not to retouch the site before performing the venipuncture.

Sodium fluoride keeps which of the following analytes intact for 48 hours? A. potassium B. creatinine C. glucose D. cholesterol

glucose Rationale Glucose is stable in a gray top tube for 24 hours at room temperature and 48 hours when refrigerated at 4-8oC. In addition to the anticoagulant potassium oxalate, the gray topped tube contains sodium fluoride which is an antiglycolytic. Sodium fluoride delays the metabolism of glucose by the red and white blood cells and platelets, helping to stabilize the glucose level until it can be analyzed. Potassium, creatinine and cholesterol have different stabilities depending on the tube type used for collection and storage temperatures.

A test tube with which of the following stopper colors has a glycolytic inhibitor? A. gray B. green C. lavender D. light blue

gray Rationale The gray tube has a glycolytic inhibitor (sodium fluoride) to maintain glucose levels along with potassium oxalate as the anticoagulant. A green tube contains heparin, a lavender has EDTA and the light blue contains sodium citrate.

A patient arrives with orders for a complete blood count (CBC), prothrombin time (PT/INR), and basic metabolic panel (BMP). Which of the following tubes should the phlebotomist collect? A. lavender, blue, red B. yellow, blue, gray C. lavender, red, SST D. yellow, gray, SST

lavender, blue, red Rationale Blood collection tubes are color coded to indicate their chemical contents. The Clinical Laboratory Standards Institute (CLSI) defines the order of drawing these tubes to prevent carryover of the contents from one tube to the next. A small amount of the chemical may be retained on the inner needle or rubber sleeve of the ETS system and contaminate the next tube thereby affecting patient results. The order is sterile (blood cultures), sodium citrate (blue), serum (red or gold with or without clot activator or gel separator), heparin (green), EDTA (purple or pink), sodium fluoride & potassium oxalate (gray). In this case, the phlebotomist should draw a blue first (PT/INR), a red next (BMP) and a lavender (CBC) last.

The physician orders a prothrombin time. Which of the following tubes should be used to collect the specimen? A. gray B. light blue C. yellow D. red

light blue Rationale Contains sodium citrate to prevent blood from clotting.

A patient is at the lab for her weekly coagulation blood work. The phlebotomist should draw a A. lavender top and fill to at least 90%. B. light blue top and fill to at least 90%. C. lavender top and refrigerate. D. light blue top and refrigerate.

light blue top and fill to at least 90%. Rationale A light blue tube is used for coagulation tests. It contains sodium citrate as an anticoagulant which preserves the clotting factors to be measured. The tube must be filled adequately as the correct patient result depends on a ratio of 9 parts blood to 1 part anticoagulant. The light blue tube does not need to be refrigerated - it should be kept at room temperature. If there is to be a delay in testing, the tube should be spun and the plasma placed in a properly labeled aliquot tube then frozen. Lavender tops (K EDTA) are not used for coagulation testing, but for hematology testing requiring whole blood such as complete blood counts (CBC).

Inadequate mixing of an anticoagulant tube is likely to result in A. hemolysis. B. microclotting. C. hemoconcentration. D. no adverse effects.

microclotting. Rationale Anticoagulants are contained in many ETS blood collection tubes to keep blood specimens from clotting. If the tubes are not adequately mixed after collection, micro clots can from. These clots can cause inaccurate patient results and interference with instrument operation. Hemolysis is the rupture of red blood cells in a specimen caused by too much mechanical pressure from too small a needle, too much vacuum on the vein or pulling too hard on the plunger of a syringe. Hemoconcentration is the alteration of amounts of components in the blood caused by leaving the tourniquet on too long.

Which of the following items is commonly found on a phlebotomy tray? A. multi-sample needle B. tongue depressor C. culture swabs D. 18-gauge needle

multi-sample needle Rationale Multi-sample needles are standard equipment on phlebotomy trays. An 18 gauge needle is very large and not used for standard blood draws, as it would be unnecessarily painful. Neither tongue depressors or culture swabs are used for blood collection.

Which of the following tubes is recommended for STAT serum testing? A. royal blue B. pink C. lavender D. orange

orange Rationale Typically a serum tube requires clotting in the upright position at room temperature for at least 30 minutes to produce the volume and clarity of serum necessary for testing. These are not usually used for STAT tests. However, a serum tube containing thrombin that clots in 5 minutes has recently been offered by a manufacturer. It is called an orange RST (rapid serum tube). The royal blue, pink and lavender tubes each contain EDTA and produce plasma after centrifugation.

Which of the following are anticoagulants found in blood collection tubes? (Select the two (2) correct answers.) A. sodium fluoride B. oxalate C. sulfate D. heparin E. thrombin

oxalate, heparin Rationale Anticoagulants are added to certain blood collection tubes to keep the specimen from clotting. These samples can then be used for testing as whole blood or centrifuged to recover the plasma. Oxalate and heparin are anticoagulants. Sodium fluoride is an antiglycolytic used to preserve glucose levels. Sulfate is a component of blood (DHEA sulfate test) and thrombin is an enzyme that aids in clotting.

A patient presents with severe thirst, fatigue, and frequent urination. The doctor orders a blood draw for a glucose level. To prevent glycolysis, which of the following additives is needed? A. heparin B. sodium flouride C. EDTA D. sodium citrate

sodium flouride Rationale The addition of sodium fluoride (gray top tube) acts as a preservative of the glucose level. This is accomplished by preventing the red blood cells from metabolizing glucose to lactic acid (glycolysis) and reducing the glucose level by as much as 10 mg/dl per hour. Heparin (green top) , EDTA (purple top) and sodium citrate (blue top) are used as anticoagulants to prevent blood from clotting in the tube.

Which of the following additives is used with a glucose test? A. sodium fluoride B. EDTA C. sodium citrate D. thixotropic gel

sodium fluoride Rationale Sodium fluoride (gray top tube) is an antiglycolytic agent that preserves glucose levels after they are drawn. EDTA and sodium citrate are both anticoagulants but neither is used for glucose testing. Thixotropic gel forms a barrier in a tube between the fluid and cells after centrifugation.

Which needle size and type is the best choice for a patient with thin skin and extremely fragile veins? A. multisample needle 22g 1 1/2" B. multisample needle 21g ¾" C. winged infusion 23g ¾" D. winged infusion 21g 1 ½"

winged infusion 23g ¾" Rationale Patients who are elderly or have received chemotherapy may have fragile veins and thin skin. They may easily bruise or develop hematomas compromising available venipuncture sites. It is prudent to balance the use of the smallest needle that will allow for a good specimen with equipment that guards against damage to the vessels and tissues. A winged infusion set with a 23 g needle and a syringe might be the best choice. Using a mutisample (ETS) system with either a 21g or 22g would exert too much pressure on the vein. A winged infusion set with a 21g needle might be too large for the vein.