CPCT Certification Study Guide Notes

Chain of Custody Guidelines

• Maintains control and accountability for each specimen from collection to disposal.
• All individuals handling a specimen must document their identity and each specimen transfer on the chain-of-custody form.
• Form Requirements:
  • Name and identifying information of the patient, body, subject, or object the specimen came from.
  • Name of the person who obtained and processed the specimen.
  • Date, location, and signature of the person attesting that the specimen is correct and matches documentation.
  • Signature and date from every person who had possession of the specimen, even for transporting.
• Specimen Transfer:
  • Label the specimen correctly.
  • Place it in a biohazard bag with a permanent seal to verify that no one has opened until analysis.
• These specimens are legal evidence; there must be no tampering with them until they reach their final destination.
• An intact seal provides evidence that there has been no tampering during the specimen’s transfer to the laboratory.
• Situations Requiring Chain of Custody:
  • Forensic analysis
  • Workplace drug testing
  • Drug testing of professional athletes
  • Neonatal drug testing
  • Blood alcohol content (BAC) testing
  • Occasionally DNA analysis, rape test kits, and parentage testing

Forensic Specimens

• Forensic laboratory analysis involves various types of specimens:
  • Vaginal swabs after rape
  • Blood and body fluids from crime scenes
  • Postmortem specimens from autopsies
• Special handling of specimens is crucial because they might be:
  • Decomposing
  • Available in only trace amounts
  • Require analysis by a forensic scientist in extreme environments.
• Forensic specimens also involve toxicology testing of substances after poisoning or overdose.
• Collecting these specimens can require special training, experience, and supervision.
• Unlike specimens collected in a clinical setting, forensic specimens can be in any condition, including clotted, or in containers that would otherwise be unacceptable.

Drug Testing

• Urine drug tests determine nonprescription drugs in a patient’s system.
• Patient privacy and accuracy of results are crucial.
• Some situations require monitoring of the urine collection, and a chain-of-custody form will accompany the collection process.
• Confirm completion of the form in its entirety. Everyone who handles the specimen must sign and date the form.
• The facility might issue other instructions for performing this type of collection.
• These tests can be essential for legal situations, so make sure to understand and perform all the necessary steps.
• U.S. Department of Health and Human Services federal drug testing is mandatory for some government employees and private-sector employees.
• Workplace drug testing often follows the U.S. Department of Transportation’s mandated testing regulations, which are an industry standard.
• Many employers require urine drug testing and use the Federal Drug Testing Custody and Control Form (CCF) for the process.
• This form must document the handling and storage information for specimens from the time they are obtained to their final disposal.
• Staff collecting these specimens must undergo training and evaluation in the correct use of the CCF per federal guidelines.
• The process for collection has extremely specific guidelines to ensure that employees providing the specimen cannot tamper with it:
  • Adding water to dilute it
  • Replacing it with urine they previously collected from someone else and concealed in clothing or a handbag.
• Urine drug tests can usually detect marijuana use within the past week and the use of cocaine, heroin, and other substances within the past 2 days.
• They do not measure the degree of impairment or the frequency of use.
• Workplace drug testing:
  • Ensures compliance with federal regulations, customer contracts, and insurance carrier requirements
  • Reinforces a company’s no-drug-use policy
  • Minimizes the risk of hiring an employee who uses illicit drugs
  • Identifies employees who use illicit drugs so that employers can enforce disciplinary action
  • Improves the safety and health of employees
• Sports-related drug testing:
  • Detects the use of stimulants to enhance athletic performance (amphetamines, anabolic steroids, alcohol, diuretics, street drugs, peptide hormones, anti-estrogens, beta2 agonists)
  • Encourages regulation of nutritional and dietary supplements
  • Analyzes blood and urine to detect blood doping or the use of erythropoietin
• Neonatal drug testing:
  • Detects the use of cocaine, opiates, amphetamines, methamphetamines, and phencyclidine, which cause prenatal drug exposure and neonatal abstinence syndrome (withdrawal)
  • Requires obtaining specimens for analysis within 24 hours after childbirth to detect recent drug use
  • Confirms maternal drug use 24 to 72 hours prior to childbirth if the newborn’s urine is positive for these substances
• Law enforcement officers who detain individuals they suspect of driving under the influence might conduct various sobriety tests.
• Depending on state laws, they might request or require a urine, blood, or breath test.
• The most accurate of these methods for identifying alcohol levels is blood specimen analysis from a routine venipuncture or dermal puncture procedure.
• In the U.S., the legal limit for BAC is 0.08%, or 80 mg/100 mL.
• Drivers younger than age 21 must have no detectable alcohol in their blood.
• When collecting specimens for BAC testing, follow the chain-of-custody guidelines and specific collection techniques.
• Clean the venipuncture site with an antiseptic, such as chlorhexidine, that does not contain alcohol.
• Using alcohol for this purpose could lead to a false-positive result. Do not use iodine swabs because they contain alcohol.

Venipuncture

• Many factors affect equipment choices for blood collection.
  • Facility policies
  • Types of tests the laboratory staff will perform
  • Needs and condition of the patient
  • The setting in which you will collect the blood
• In an inpatient setting, you will use a phlebotomy tray or cart that you take to the patient’s room.
• In an outpatient setting (provider’s office, laboratory’s collection center), you most likely will have a phlebotomy station, where supplies and equipment are in a cabinet close to the phlebotomy chair.
• It is your responsibility to help make sure patients who come to the facility are safe throughout their visit.
• Before the blood collection, review the requisition to know what supplies you need.
• Assemble the equipment and double-check the requisition to make sure you have everything you need before you place the tourniquet on the patient.
• It gives the patient a feeling of confidence when all supplies are there, ready for the collection.
• When gathering supplies, also check expiration dates and look for manufacturing or packaging defects.
• Arrange supplies in a way that keeps both you and the patient safe.
• Because the patient eats meals from the overbed table in an inpatient setting, avoid placing the phlebotomy tray on this surface.
• Instead, use a chair, or put a towel or disposable drape under the phlebotomy tray.
• It is also important to keep the cap on the needle until right before the blood collection.
• Your priorities and goals during blood collection are to:
  • Keep the patient safe
  • Provide comfort
  • Obtain specimens efficiently and successfully
• Positioning the patient properly helps achieve these goals.
• In inpatient settings, you can perform the procedure with the patient in a comfortable position in bed.
• This adds an extra component of safety in case of fainting.
• In outpatient settings, have the patient sit in a venipuncture chair with comfortable, adjustable armrests and a padded locking bar to prevent falls.
• Chairs with adjustable height make specimen collection easier and reduce back strain.
• Some chairs also recline for added safety and comfort.
• Never perform venipunctures with patients standing or sitting on a high stool or the edge of an examination table.
• Some facilities provide extra-wide venipuncture chairs and wheelchair stations.
• Adjust arm positioning based on the individual patient. However, the optimal position is a full extension of the arm with the palm facing upward.
• Slight rotation of the arm can help you visualize the vein and keep it from rolling when inserting the needle.
• A pillow or an armrest can improve comfort for some patients. Another technique is to have the patient support the arm under the elbow with the other hand.
• Observe the patient’s arm for any factors that could affect the blood collection (tattoos, scarring, hematomas).
• Many patients prefer one arm over the other for the collection, so ask the patient which arm you should use. Start palpating for a vein on the arm the patient prefers.
• If you cannot locate a vein on that arm, ask for permission to palpate the other arm.
• First palpate the veins in the antecubital area.
• The first choice for a vein is usually the median cubital.
• The median cubital vein is firmly anchored in the middle of the arm on the anterior surface and is most often the least painful to access for the patient.
• The second choice is the cephalic vein, which is toward the outside (lateral) surface of the arm.
• Accessing the cephalic vein might be a little more painful for the patient, but it is the next best choice after the median cubital.
• For patients who are obese, the cephalic tends to be the easiest vessel to locate for a venipuncture.
• When you cannot locate the cephalic or median cubital vein, your next step is to check for an accessible hand vein.
• If you still cannot find a vein, attempt to locate the basilic vein, which is prominent in some patients’ arms; however, it should be your last resort for a blood collection.
• The radial nerve and the brachial artery are close to the basilic vein, so the risk of accidentally disrupting the nerve or artery increases with this vessel choice.
• If an attempt to do a blood collection from the basilic vein is not successful, never reposition the needle.
• The ideal vein to choose is well-anchored, feels spongy and bouncy, is straight, and is easy to access with a needle.
• When a patient has an IV catheter in an arm, first try to find a vein in the other arm.
• If you cannot, follow your facility’s procedure for the blood collection. It might allow stopping the infusion temporarily.
• Whether IV fluid is infusing or not, perform the venipuncture distal to the IV catheter’s insertion site to help prevent contamination of the specimen with the infusing fluid.
• It is especially important to collect the blood from the opposite arm, or below the IV site, when a patient is receiving a blood transfusion.
• To collect the blood above the IV site could mean that the blood to be tested is that of the donor, making the test results inaccurate.
• Avoid using the arm on the affected side of a patient who has had a mastectomy. It could increase the patient’s risks of infection and pain.
• Avoid performing a collection in any skin that has a tattoo.
• Do not collect blood through a hematoma because it could affect test results and cause more pain for the patient.
• When a patient has edema (swelling), avoid the area due to the possibility of the blood sample including excess fluid.
• It can also be painful for the patient because the skin becomes very tight in edematous areas.
• Do not try to collect blood from an area that has scarring because it can be difficult to find a vein there, and it can be painful for the patient.
• Do not collect blood from a sclerotic vein, because blood flow from that vein is likely to be inadequate, and it can be painful for the patient.
• Position the tourniquet about 7.6 to 10.1 cm (3 to 4 inches) above the antecubital area for collections in that region or above the wrist bone for dorsal hand collections.
• When the tourniquet is too far from the venipuncture site, it might not provide enough tension. If the tourniquet is too close to the site, the vein can collapse.
• Apply tourniquets gently yet tight enough to assist with finding the vein. A loose tourniquet can make it difficult to find the vein. A tight tourniquet can slow or stop blood flow and can also hurt the patient.
• Apply the tourniquet in such a way that removing it is quick and easy.
• It is also important to remove the tourniquet within 1 minute of application, preferably as soon as blood begins to flow. After 1 minute, hemoconcentration begins.
• Hemoconcentration alters the blood and can yield inaccurate results.
• Remove the tourniquet gently because the needle will still be in the vessel. Discard or reuse tourniquets as your facility specifies. If a tourniquet is not available, inflate a blood-pressure cuff pump to 40 mm Hg on the arm instead. Release prior to the 1-minute point or when blood flow is established, similar to the tourniquet.
• Once you have applied the tourniquet, begin to palpate, starting from the middle of the antecubital region and moving toward the outside of the arm. Begin with light pressure, your finger bouncing against the skin, up and down, without leaving the surface of the skin.
• Veins feel spongy and bouncy. Tendons feel hard—similar to bone—and you must avoid them. Also, avoid veins that feel hard because they could have sclerosis or scarring.
• If you cannot feel any veins with light pressure, increase the pressure but avoid hurting the patient. Use only one finger, preferably the index finger of your nondominant hand.
• Palpate with the very tip of your finger, which can be the most sensitive, and avoid palpating with your thumb.
• Do not select a vein that you can see but not feel. It could be a superficial vessel that will not be large enough to allow the needle to enter for a blood collection.
• Always palpate with the same finger of the same hand to help train your brain to find veins easily. Palpating with your nondominant hand also allows you to palpate again if you insert the needle but miss the vein—but without switching hands, which can disrupt the needle.
• Once you find a vein, move your finger along the length of the vessel to determine its direction. Palpate also for the depth of the vein and the size of the vessel. Discovering this information will help you decide which equipment to choose and how to align the needle when entering the vein.
• When a vein is difficult to find, there are a few procedures that can help the vein become more prominent. Because veins rise to the surface to help cool the body and the blood, use a warm cloth or an infant heel warmer on the antecubital space, the dorsal part of the hand, or the infant’s heel. Just make sure that it isn’t hot enough to burn the patient’s skin.
• For arm or hand collections, hang the arm below the patient’s heart to allow gravity to help fill the veins with blood.
• Some rubbing of the area can help improve circulation, but avoid too much friction because it can affect blood test results. Do not slap or smack the area of the palpated veins. This can hurt your patient, and it could constitute an act of battery.
• Always wear gloves when cleansing a patient’s skin in preparation for blood collection.
• Use a new individually packaged 70\% alcohol pad or swab. Open the package carefully to avoid wetting your fingers and excessive touching of the pad.
• Cleanse the area where you will perform the venipuncture with a friction scrub using back-and-forth movement over an area of skin about 6.1 x 6.1 cm (2.5 x 2.5 in). Allow the alcohol to air-dry so that it can perform its antiseptic action.
• Performing the blood collection when the alcohol is wet can also cause the patient to feel a stinging sensation when the needle enters the skin. Do not blow on the site because this can contaminate the skin and the specimen. If the alcohol seems to stay wet, dab the site gently with sterile gauze to remove the excess alcohol. You can use an alcohol swab stick in the same way. Do not touch the area after cleansing it. If re-palpation is necessary, repeat the cleansing process.
• When performing a venipuncture in the antecubital region, keep the bevel of the needle facing up. Insert the needle at a 15° to 30° angle, depending on the depth of the vessel. The deeper the vein is in the arm, the greater the angle you should use—but do not exceed 30°. Collect blood from a vein close to the surface of the skin at a shallower angle—but no shallower than 15°. With an angle greater than 30°, you might go too far into the antecubital region and possibly hurt the patient or injure a nerve. With an angle that is too shallow, you might force the bevel to adhere to the wall of the vessel (slowing down or stopping the blood flow), or missing the vein entirely (going between the vessel and the skin).
• The correct angle for a dorsal hand blood collection is 10°.
• When performing a dorsal hand collection, use a shallower angle to accommodate the large number of nerves and tendons in the hand.
• Perform the insertion in all venipuncture locations with a quick, smooth movement to pierce the skin. A swift entry helps reduce the pain for the patient and helps keep the vein from moving away from the needle, thus resulting in an unsuccessful attempt.
• Gauging the depth of the entry requires an understanding of where you will insert the needle and puncture the skin and the wall of the vessel. Insert the needle until you feel a change in resistance.
• Then, stop the insertion and gently push the evacuated tube into the distal end of the needle. You can feel resistance when you puncture the skin, another resistance when you puncture the wall of the vein, and then a change in the resistance that indicates that you are in the lumen of the vein, from which blood will flow optimally.
• Inserting the needle to a point where it only partially penetrates the vein will result in blood leaking into the surrounding tissues and resulting in a hematoma. Inserting the needle too deeply can pierce through the vessel, thus transfixing the vein and yielding no blood.
• The insertion should also follow the direction of the vein to help prevent missing the vessel or piercing through the side of the wall of the vessel.

Venipuncture Methods

• Evacuated Tube System (ETS)
• ETS equipment includes:
  • Gloves
  • Use a new pair of well-fitting vinyl or nitrile gloves for each venipuncture. Never reuse gloves. If latex gloves or other latex products are used, consult the patient’s medical record for potential latex allergies.
  • Isopropyl alcohol swabs or pads.
  • Use alcohol swabs or pads to cleanse the skin before inserting the needle. Discard them after one use.
  • Gauze pads.
  • Use sterile, disposable gauze pads to apply pressure to assist with clotting and to cover the venipuncture site. Never reuse gauze. Do not use cotton balls, which can leave fibers on the puncture site and can remove a clot when wiping away or pulling off the fibers.
  • Tape, self-adhesive wrap, or adhesive bandages.
  • Apply these to the puncture site to promote clotting.
  • Tourniquet
  • These come in pliable straps (latex-free are recommended) or hook-and-loop fastener varieties. You may reuse tourniquets—but discard them if they become soiled or obviously contaminated. If a tourniquet is not available, use a blood-pressure cuff inflated to 40 mm Hg.
  • Needles
  • For routine venipuncture, use 20- to 23-gauge hollow needles, 1 to 1.5 inches long. 21-gauge is the most common. They are sterile, so dispose of them in a sharps container after each use. Needles must have a safety device that completely covers the needle after use. Never reuse needles. ETS needles are double-ended. You insert one end into the patient’s vein, while the other end punctures the stopper on the evacuated tube. The sheath that covers the tube end of the needle helps keep blood from dripping when you switch to the next tube. Before and after use, be careful with the sheathed side of the needle and the side that punctures the patient’s skin.
  • Hub, adapter, needle holder
  • These help guide the tubes toward the needle to initiate blood flow into the evacuated tube.
• Blood collection tubes
  • Blood collection tubes for adults are glass or plastic, about 3 inches long and 0.5 to 0.75 inches wide. The inside of a blood collection tube is sterile, but the outside is not. The tubes have an opening at one end with a rubber stopper sealing it.
  • The manufacturing process removes the air in the tubes, and the rubber stoppers keep the negative pressure of the vacuum intact. When the tube end of the needle punctures the stopper, it helps draw blood into the tube. Because of this vacuum, do not remove the stopper of a tube before a blood collection.
• Pediatric blood collection tubes
  • The vacuum inside adult blood collection tubes is relatively strong and could collapse a child’s vein. Blood collection tubes for children are otherwise identical but smaller, and they exert less vacuum pressure.
• Color-coding of blood collection tubes’ stoppers helps identify which type of tube to use for which laboratory test. The colors relate to the various additives (or lack of additive).
  • Check the label for which additive is in the tube, the expiration date, and the amount of blood the tube will hold. Make sure the additive is the one for the test the patient requires; do not rely solely on the color. Always confirm the tube with laboratory staff if you are unfamiliar with the test.
  • The most common additives are either anticoagulants (which prevent clotting) or clot activators (which promote clotting). Some evacuated tubes contain a gel separator that does not alter the blood sample but assists in the processing of the blood after centrifuging.
    Additive | Stopper Color | Test Type
    ---------------------------------|-----------------------|------------------------------------------
    sodium citrate | light blue | coagulation
    heparin | green | chemistry
    ethylenediaminetetraacetic acid (EDTA) | lavender | hematology
    potassium oxalate, EDTA or fluoride | gray | chemistry
    none, EDTA, or heparin | royal blue | chemistry
    acid citrate dextrose | light yellow | blood bank
    none | red | chemistry
• Evacuated tube system procedure
  1. Position the patient’s arm in a slightly bent, downward position.
  2. Apply the tourniquet. Palpate for a vein. Choose the most accessible vein.
  3. Cleanse the venipuncture site with a friction scrub using back-and-forth movement.
  4. Uncap the needle, and inspect it for burrs and blunt edges.
  5. Stabilize the vein with the thumb of your nondominant hand by gently but firmly pulling down on the skin below the vein.
  6. Alert the patient to expect a pinch or poke.
  7. Insert the needle at a 15° to 30° angle (10° for a hand collection).
  8. Gently push the evacuated tube into place, label down, using the proper order of the draw.
  9. Make sure blood is flowing into the tube.
  10. Remove the tourniquet before 1 minute.
  11. Remove each tube, inverting it immediately.
  12. Remove the needle swiftly at the same angle of insertion.
  13. Provide pressure at the site of the collection. Check the site to make sure that it has stopped bleeding. If the site is still bleeding, continue to provide pressure.
  14. Apply an adhesive bandage, gauze, and a self-adhesive wrap—or gauze and tape—over the puncture site.
• Winged Infusion (Butterfly) Method
• Use a winged infusion device when the patient has small or difficult-to-access veins. Because the holders on either side of the needle look like wings, it is commonly referred to as a butterfly.
• The difference is how the butterfly attaches to the adapter and how it punctures the patient’s skin.
• The winged infusion set consists of a 21- to 23-gauge, hollow, ¾-inch long sterile needle with a beveled edge, a short length of flexible plastic tubing, and a sterile sheathed needle at the other end of the plastic tubing. The second needle attaches to the adapter, similar to the ETS method.
• With this method, you will need gloves, gauze, alcohol pads, an adapter/hub, and bandages. Butterfly needles are individually packaged.
• If the package is open or torn, do not use the needle and dispose of it into a sharps container.
• The steps for collection are almost the same as for the evacuated tube system with the following exceptions.
• For the butterfly method, have the patient position the hand with the palm facing down. Fit the hub end onto a syringe or an evacuated tube adapter.
• Before the collection, look for the safety activation mechanism so that you do not accidently activate it before the collection is complete. Knowing where the safety is located also helps prevent an accidental needlestick when the collection is complete. Instead of holding the entire device in one hand like the ETS system, use one hand to hold the needle, not the adapter, during insertion.
• After you insert the needle and it is in the vein, you will see a flash of blood at the base of the winged infusion set. This is your indication to push the evacuated tube into place or slowly pull back on the plunger of the syringe for the collection. As the second needle punctures the stopper, the rubber sheath slides back, allowing the needle to pierce the tube and blood to flow from the vein into the collection tube.
• Syringe Method
• Use the syringe method for patients who have fragile veins that collapse easily. ETS tubes, which contain a vacuum, collect the blood from the patient at a rapid rate that you cannot determine or control. In the syringe method, the plunger on the barrel of the syringe allows you to adjust the rate of blood withdrawal manually; this reduces the risk of a fragile vein collapsing.
• For this method you’ll use gloves, alcohol preps, gauze pads, bandages, and evacuated tubes, but you will first collect the blood in the syringe and then transfer it into the tubes.
• Other supplies for this method include the following.
  • Syringe
    • Attach the syringe to the needle so the barrel of the syringe will hold the blood during collection. Use the plunger to withdraw the blood, and watch the numbers on the syringe barrel to gauge the amount you need for the test. Syringes are of various sizes, but 10 mL and 20 mL are the most common for blood collection.
  • Needles
    • Needles are hollow with a beveled end and of the same length and gauge. OSHA requires a safety device that completely covers the needle after use. Unlike the ETS method, the needles are single-ended.
  • Transfer Device
    • This is a plastic device, similar in appearance to an adapter with a hub, with a sheathed needle on the end. Screw the transfer device onto the syringe, where you previously attached the needle. The barrel of the transfer device is large enough to allow an evacuated tube to slide in and snap onto the needle to allow its vacuum to draw the blood into the transfer device.
• Syringe method procedure
  1. Have the patient sit or lie down.
  2. Assemble the equipment. Pull the plunger in and out of the syringe to ensure a smooth collection. Push the plunger all the way forward to make sure that there is no air in the barrel.
  3. Calculate how much blood is necessary to fill the tubes for the tests required. Determine how much blood you will collect into the syringe, and then round up to make sure that you collect enough blood to fill the tubes completely.
  4. Position the patient’s arm in a slightly bent, downward position.
  5. Apply the tourniquet. Palpate for a vein and choose the most accessible one.
  6. Cleanse the venipuncture site with a friction scrub using back-and-forth movement.
  7. Uncap the needle, and inspect it for burrs and blunt edges.
  8. Stabilize the vein with the thumb of your nondominant hand by gently but firmly pulling down on the skin below the vein. Alert the patient to expect a pinch or poke.
  9. Insert the needle at a 15° to 30° angle (10° for a hand collection).
  10. Pull back slowly on the plunger with your nondominant hand to collect the blood. Remove the tourniquet before 1 minute.
  11. Collect the correct amount of blood into the syringe to fill the tubes the tests require.
  12. Remove the needle at the same angle as for insertion.
  13. Apply pressure at the site of the collection. Ask patient to place pressure on it, or have another staff member maintain pressure.
  14. Use a transfer device to move blood from the syringe into evacuated tubes in the proper order of the draw. Allow the vacuum to fill the tubes; do not push down on the plunger of the syringe.
  15. Invert the tubes gently to mix in the additives.
  16. Check the site to see that it is not still bleeding. If the site is still bleeding, continue to maintain pressure. Apply an adhesive bandage, gauze and a self-adhesive wrap, or gauze and tape over the puncture site.

Specimen Handling and Transport

• Handling requirements include pre-collection specifics. When tests require specific timing, heat, cold, or protection from light, your role in transporting specimens to the laboratory after collection is as important as the venipuncture for securing a high‑quality test result.
• Delivery of specimens from clinics or blood-collection stations to reference laboratories should be as prompt as possible. With delays between collection and processing, glucose in blood cells can break down and interfere with results of various tests, such as phosphorus, glucose, aldosterone, calcitonin, and enzymes.
• It is also essential to transport microbiology specimens quickly so that the laboratory technicians can transfer the specimens to the culture medium or incubator. These samples include blood, urine, sputum, wound exudate, stool, and other body substances. The sooner they get to the environment where micro-organisms can grow, the sooner the technicians can identify them and generate the results so that the patients can receive specific treatment.
• The delivery process must include adequate specimen handling, packaging, and communication with the courier or other delivery services. Coordinate the schedule of pickups, including the process for delivering stat specimens, where to place the specimens for pickup, and how to document the delivery process accurately and completely.
• For thermolabile specimens—which require a specific temperature—use a heat source, heat block, ice slurry, refrigerator, or freezer. Do not use cold or ice packs because they are unreliable. Avoid fluctuating temperatures.
• Tests that require specific handling of specimens include ammonia and lactic acid, for which the blood tube must sit in an ice slurry immediately after collection. For cold agglutinins, the sample must remain at body temperature—37° C (98.6° F). Protect blood samples for bilirubin and folate levels by wrapping the blood tube in foil. Store specimens for blood gas tests at room temperature for 15 to 30 minutes or in an ice slurry for up to 1 hour. Delivery speed is crucial to prevent the loss of gases from the blood prior to analysis. For coagulation tests, analysis should take place within 1 hour of collection. Prothrombin time is an exception. A delay up to 24 hours at room temperature will not affect the results. Room temperature for laboratory purposes is 22° C (71.6° F). Protect all photosensitive specimens from light.
• For timed tests, make sure the patient has satisfied the testing requirements. For example, a 2-hour postprandial blood glucose level requires a fasting blood glucose level plus a blood glucose test exactly 2 hours after the patient started eating a meal or consumed the liquid glucose preparation.
• Other timed tests include peak and trough values for antibiotics like gentamicin or vancomycin, for which you must collect blood samples at a specific time after the administration of the antibiotics. Coordinate these procedures with the nurses to ensure accurate results.
• Label every type of collection container immediately after collection with the patient’s name and identification number, the date and time of collection, and the specimen type. Position it correctly on the tube or container. If the facility requires it, sign or initial the specimen. Then compare the information on the label with the patient’s wristband or verbally verify it with the patient. If the container has a lid, make sure that the label is on the container, not on the lid.
• Hand delivery is direct to a reference laboratory, following timeliness of delivery guidelines, completing log-in processes, and using necessary carrying devices (trays, carts, tube racks, leakproof containers).
• Pneumatic tube systems are most often found in an inpatient setting. These systems have enhanced mechanical reliability, increased transport distance and speed, specific control mechanisms, and shock-absorbing features to help prevent hemolysis of blood samples. There is an inner padding that lines the canister and separates the blood tubes. Disruption of red blood cells during this type of transport can affect the results of tests for potassium, plasma hemoglobin, lactate dehydrogenase, and acid phosphatase. Coagulation specimens also need protection from shock and vibration to prevent platelet activation. For most other tests, this is an efficient means of transport that does not interfere with analysis.
• Automated carrier uses a transport vehicle, such as a motorized container car that travels on a network of tracks to various destinations within the facility. This includes some of the same features of pneumatic tube systems.

Dermal Punctures

• A dermal puncture removes a much smaller volume of blood than a venipuncture. You will perform dermal punctures—also called capillary blood collections, finger sticks, or heel sticks—for a variety of reasons:
  • For tests that require a small amount of blood
  • When a patient does not have an accessible vein but a blood collection is essential
  • When a laboratory test requires capillary blood
  • For a patient who is at risk of iatrogenic anemia
• Dermal punctures are common for many point-of-care (POC) blood tests, including glucose, cholesterol, and hematocrit determinations.
• There are several types of collection receptacles for dermal punctures, including capillary pipettes and microcollection tubes. For other types of tests, you will touch the blood to specialized filter paper or to a strip that works with a monitor, such as a glucometer.
• The patient’s age, requested tests, and health status all assist in determining whether a venipuncture or dermal puncture is necessary. For infants younger than 1 year, a dermal puncture is preferable because it requires less blood. Infants’ veins are small, and numerous venipuncture procedures can damage the blood vessels.
• Some adults can have compromised veins that are difficult to find and access. For these patients, use a dermal puncture to collect blood. Patients who are underweight are also at risk for iatrogenic anemia, so using a smaller amount of blood to fill a microcollection tube makes sense. You can perform a dermal puncture when there is no need for a large volume of blood, for repeated testing (such as for glucose monitoring with a glucometer), and when the specific test requires capillary blood.
• A dermal puncture blood specimen contains three types of blood: arterial, capillary, and venous. When you perform a dermal puncture, document this on the medical requisition to alert the laboratory staff that the blood has a different composition than venous blood. Follow any specific instructions from the manufacturer for a prepackaged test kit or strips used with a device such as a glucometer.

Finger Stick

• For adults and children older than 1 year, perform the dermal puncture on the third or fourth finger of the patient’s nondominant hand. The fifth finger is too thin, and the bone is too close to