COURSE DESCRIPTION. Page 1 of 35. Rev 4.0 February 2015

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1 COURSE DESCRIPTION Many healthcare professionals view the collection of blood as a simple procedure. However, phlebotomy is a detailed procedure that, if not performed correctly, can affect the accuracy of laboratory test results and can even cause permanent disability in the patient. Phlebotomy is also an evolving profession. What was the standard of practice five years ago is perhaps now no longer the standard of practice. This CE module answers questions asked by practicing professionals about a wide range of topics including order of draw using a syringe, phlebotomy regulations, chain of custody procedures, blood cultures, preanalytical errors, collecting microsamples, bleeding times, glucose tolerance testing, and more. Rev 4.0 February 2015 Page 1 of 35

2 COURSE TITLE: More Frequently Asked Questions about Phlebotomy Author: Lucia Johnson, MA Ed, CLS(NCA), MT(ASCP)SBB Director of Continuing Education National Center for Competency Testing Number of Clock Hours Credit: 6.0 Course # P.A.C.E. Approved: Yes X No OBJECTIVES Upon completion of this continuing education module, the professional should be able to: 1. List the order of draw as recommended by Clinical Laboratory Standards Institute (CLSI). 2. Describe examples of lawsuits that resulted from the practice of phlebotomy. 3. State what phlebotomists can do to avoid legal action being taken against them. 4. Identify the complications resulting from drawing blood via vascular access devices. 5. Identify organizations that offer voluntary accreditation to healthcare facilities and laboratories. 6. Describe chain of custody procedures. 7. Describe the glucose tolerance test procedure. 8. Identify common laboratory tests performed on each color of vacuum tube. 9. Describe collection of blood from foot/ankle veins, bilateral mastectomy patients, amputees, and cancer patients with poor veins. 10. Describe the role of CLSI, College of American Pathologists (CAP), and The Joint Commission in phlebotomy practice. 11. Identify the pros and cons of collecting blood using a butterfly, i.e., winged infusion set. 12. Describe the collection of blood cultures. 13. Describe procedures to follow when a patient feels faint or faints. 14. Determine the volume of blood that can safely be removed from an infant at any one time or cumulative for a hospital stay of one month. 15. Identify labeling requirements for blood bank specimens. 16. Describe the use of PT tests in the monitoring of Coumadin therapy. 17. List lab tests that require fasting specimens for accurate test results. 18. State the two cardiac enzymes used to diagnose acute myocardial infarction and the times specimens are generally collected. 19. Describe physiological factors affecting basal state, patient clinical conditions affecting venipuncture, and technical venipuncture conditions that can lead to preanalytical errors. 20. Describe the use of a blood transfer device. 21. Name bloodborne pathogens that can be transmitted via needlestick injury. 22. Describe what to do in the event a patient refuses to have his/her blood drawn. 23. Describe what to do in the event a patient does not have an identification band. Page 2 of 35

3 24. Identify how a phlebotomist can protect him/herself in a patient isolation room. 25. Describe how to collect a blood specimen on an unconscious patient. 26. Describe skin puncture procedures. 27. Describe how to fill capillary tubes, mini-collection containers, and filter paper circles. 28. Identify situations where 21- and 23-gauge needles are preferred for use. 29. Describe a bleeding time procedure. 30. Identify venipuncture equipment and materials that are disposed into sharps containers. 31. List the order of draw when using a syringe. 32. Identify issues relating to incorrect filling of filter paper circles for newborn screening tests. 33. List causes of hemolysis and tests affected by the presence of hemolysis. Disclaimer The writers for NCCT continuing education courses attempt to provide factual information based on literature review and current professional practice. However, NCCT does not guarantee that the information contained in the continuing education courses is free from all errors and omissions. Page 3 of 35

4 MORE FREQUENTLY ASKED QUESTIONS ABOUT PHLEBOTOMY QUESTION 1: What is the order of draw when you are using a syringe? Answer: The recommended order of draw is used for both glass and plastic venous blood collection tubes. The same order of draw is used for collections using a syringe or an evacuated (collection tube & tube holder) system. Order of Draw Stopper Color Tube 1 varies Blood culture bottles Yellow top SPS tubes Any other test that must be sterile 2 Light blue top Contains sodium citrate anticoagulant Tests run on plasma 3 Red top with no additives Gold top with clot activator (micronized silica particles) and gel (polymer) for barrier Red/black top with clot activator (micronized silica particles) and gel (polymer) for barrier Tests run on serum 4 Green top with lithium or sodium heparin as anticoagulant 5 Lavender (purple) top with liquid EDTA anticoagulant (glass tube) or spray-dried EDTA anticoagulant (plastic tube) Pink top with spray-dried EDTA anticoagulant 6 Gray top with sodium fluoride as glycolytic inhibitor; if only sodium fluoride is present, serum is produced Some tubes also have potassium oxalate or EDTA as anticoagulant 7 Yellow top Solution A or Solution B acid citrate dextrose (ACD) solution Common Tests/Notes Blood culture bottles, yellow stopper with sodium polyanethol sulfonate (SPS) PT, PTT, TT, specific coagulation factor assays such as Factor VIII Tube must be filled to capacity for accurate test results For chemistry and serology tests that are performed on serum Tubes with gel barriers cannot be used for most therapeutic drug testing For chemistry tests that are performed on plasma Tests for lithium should not be collected into green top tubes containing lithium heparin Lavender top: whole blood hematology tests such as CBC, H&H, WBC, reticulocyte count, platelet count, and more Pink top: all blood bank tests; tube has label that meets AABB requirements for patient identification Serum/plasma glucose Some flow cytometry tests, HLA (white blood cell) typing and crossmatch for organ/bone marrow transplant; specific labs may specifically request Solution A or Solution B 8 All other tubes in no particular order unless otherwise instructed (black, navy, tan top tubes) *See following page. Page 4 of 35

5 *Special notes o Other tubes Black top tube: contains sodium citrate anticoagulant; used only for erythrocyte sedimentation rates (ESR, sed rates) Tan top tube: contains sodium heparin (glass tubes) or EDTA (plastic tubes); tube is certified to contain less than 0.1 µg/ml (ppm) lead; used to lead levels Navy top tube: contains sodium heparin, EDTA or no anticoagulant; stopper and tube have low levels of trace elements; used for lead, trace elements, toxicology, and nutritional chemistry testing o Some laboratories conduct internal studies to determine order of draw specific for their testing. For example, the Mayo Clinic requests tubes for lead and/or trace metal testing be collected first. Their studies show that the backend of a needle (the end that punctures the tube top) pick ups trace metal contamination from stoppers other than tan or navy and this contaminates the blood collected for trace metals. o Healthcare facilities should be using the most current recommended order of draw unless they have documentation supporting an alternate order of draw. The Clinical Laboratory Standards Institute (CLSI), formerly NCCLS, published the recommended order of draw in Procedures for the Collection of Diagnostic Blood Specimens by Venipuncture, H3-A6 in CLSI is an organization that promotes the development and use of voluntary consensus standards and guidelines in the healthcare community. They bring together experts in the field to research literature and develop recommendations for ways to provide quality patient testing. Many laboratory accreditation agencies require CLSI standards to be followed. QUESTION 2: As a phlebotomist, what can I do to protect myself from a lawsuit? Answer: Examples of lawsuits resulting from blood specimen collection include but are not limited to the following. Misidentification of a patient or patient specimen that ultimately results in a patient s death or prolonged recovery time, Failure to perform the skin puncture or venipuncture following the approved facility procedure resulting in harm to the patient such as nerve damage resulting from trauma to the brachial nerve, bone infection resulting from an improperly performed heelstick or fingerstick, Failure to raise a bed rail that has been lowered during the phlebotomy procedure, resulting in the patient falling out of bed and incurring an injury, Collection of a blood specimen from a patient who has refused the procedure, and Discussion or release of patient test results to unauthorized personnel. Lawsuits can be civil or criminal. Criminal law is concerned with breaking state laws. Civil law is concerned with actions between two people (or groups of people such as a business or company) and is based on any act that results in an injury or damage willfully made by a private party against another party. An example of a civil crime is malpractice. Page 5 of 35

6 Malpractice is a claim of improper treatment or negligence brought against a healthcare professional by means of a civil lawsuit. To support a claim of malpractice, a court must prove that negligence on the part of the healthcare professional caused harm to someone or something. Negligence can involve doing something carelessly or failing to do something that should have been done. There are three levels of negligence: slight (not much), ordinary (failing to act as a reasonable, careful person), and gross (willful and reckless). If the court convicts a healthcare professional of a criminal offense, fines and/or imprisonment are possible. It is important that healthcare workers responsible for the collection of blood specimens be aware of the risks involved in phlebotomy, and methods used to minimize these risks. A healthcare professional must always provide the patient with adequate information as to the method, risks, and consequences concerning a procedure allowing he/she to consent to it, i.e., informed consent. A patient has a constitutional right to refuse medical treatment. A healthcare worker who attempts a blood collection procedure without the patient s consent is violating this right and can be charged with assault and battery. The definition of assault is the threat to touch a person; battery is touching a person without their consent. In healthcare, confidentiality is maintaining the privacy of medical information about patients and employees. Information regarding an individual s test results, treatment, or condition is discussed only with those professionals responsible for the medical care of that individual. Unauthorized release of information concerning an individual can lead to a claim of breach of confidentiality or invasion of privacy. An individual responsible for collection of blood specimens can avoid legal action by doing the following. Always follow approved policies and procedures for patient identification. Always follow approved policies and procedures for labeling of patient specimens. Be cognizant of age related issues involving all aspects of collection of blood specimens, including patient safety issues, volume considerations, site of venipuncture or skin puncture, and phlebotomy techniques. Always follow approved policies and procedures for venipuncture and specimen collection. Always leave a patient room in the same manner as you found it, i.e., raise the bed rail if you lowered it to perform the venipuncture, etc. Never draw a blood specimen from a patient who has refused the procedure. Never release laboratory test information to unauthorized personnel. QUESTION 3: How do I collect blood from a PICC line or a central line? Answer: Healthcare professionals can be asked to collect blood from vascular access devices (VAD) like IV lines, central lines, and arterial lines. These devices directly access arteries or veins and can subject the patient to risks such as the introduction of bacteria directly into the blood, occlusion (moving or clotting) of the line, or the introduction of an air embolism into the blood, which may lead to death of the patient. Page 6 of 35

7 Because of these risks, phlebotomists and medical assistants are not trained to obtain blood specimens from vascular access devices as it is outside of their scope of practice. Collecting blood from vascular access devices is performed by physicians, residents, medical students, registered nurses, and for blood gas analysis, respiratory therapists who have documentation of thorough training. QUESTION 4: Who regulates the practice of phlebotomy? Answer: Only two states, California and Louisiana, have laws that require individuals who perform phlebotomy to document they have met specific qualifications to practice in the profession. The qualifications are completion of an approved phlebotomy program, successful completion of a nationally recognized phlebotomy certification exam, and periodic recertification by completion of continuing education. Other states are either investigating or in the process of licensing phlebotomists, as well as other clinical laboratory professionals. In other states, it is the employer s responsibility to determine the qualifications of phlebotomists. While one employer may be willing to provide on-the-job training to an individual with some patient care experience, others may require experience, and/or national certification. Many employers require annual continuing education for their employees. So who regulates the employers? Most healthcare facilities are voluntarily accredited by one or more organizations. Hospitals, outpatient surgical centers, and long-term care facilities are often inspected and accredited by The Joint Commission (TJC) Doctor office laboratories are often inspected and accredited by the Commission on Laboratory Accreditation (COLA), and hospital laboratories are often inspected and accredited by the College of American Pathologists (CAP) and the American Association of Blood Banks (AABB). All of these organizations require that phlebotomists (and other personnel) have education and training necessary to perform job requirements, have entry-level competencies documented upon hire, undergo annual competency assessment, and participate in continuing education activities to update and improve their knowledge and skills. QUESTION 5: What are chain of custody procedures? Answer: When the results of blood or urine testing have legal ramifications, the control and accountability of the specimen is documented from the time of collection to the time of disposal. This assures the specimen is tamper-proof. A chain-of-custody form provided by the police department or the laboratory testing the specimen(s) is used for documentation. The responsibility of the phlebotomist (or other healthcare professional )is to document the identification of the patient or subject, the date/time the specimen was collected, and place his/her name and signature on the form. The phlebotomist then places the specimen in a specimen transfer bag and permanently seals the bag to assure it only opened for analysis. The transfer bag may also have a place to indicate the name and signature of the individual who placed the specimen in the bag and sealed it for transport for analysis. Page 7 of 35

8 On some occasions, phlebotomists have had to testify in court that they collected a specific specimen and it is their name and signature on the chain-of-custody forms. QUESTION 6: Can you tell me about a GTT procedure? Answer: A glucose tolerance test (GTT) is a diagnostic test for diabetes. Either the physician or the laboratory should give the patient complete instructions about the procedure prior to the day of testing. Instructions should include the following dietary recommendations to assure reliable test results. 1. Eat well-balanced meals, including carbohydrates, three days prior to the test. 2. Fast 12 hours before the test. 3. Drink water during the fast and procedure but no other beverages, including sugar-free drinks, diet beverages, and unsweetened tea/coffee. Do not smoke, chew tobacco, or chew gum (including sugar-free) during the fast and procedure. 4. Do not eat anything during the procedure, including sugar-free candy. The actual procedure starts with the collection of a fasting blood glucose. After the results are known and are within a given range, a standard load of glucose solution (e.g., Glucola ) is given. If the fasting blood glucose is abnormal, the appropriate individuals notifies the doctor before the glucose solution is given. If the fasting result is too high, the doctor may discontinue the procedure, as it may be dangerous to the patient to ingest the glucose solution. The glucose solution should be drunk within five minutes. Blood specimens are then drawn at set times for a two to three hour period following the glucose administration. Specimens are generally collected at 30 minutes, 60 minutes, 2 hours, and 3 hours after ingestion of the glucose solution. The patient should drink water throughout the procedure. If the patient vomits, has a seizure, or faints, the physician must be notified immediately to decide if the procedure may be stopped. Ingestion of food or beverages other than water would result in invalid test results and the procedure should be discontinued. When the procedure is completed, the glucose results are graphed against the time the blood was collected. From this graph, it can be determined if the patient has an abnormal response. If the results are elevated, diabetes can be confirmed. If the results are decreased, the patient may have too much insulin in his/her system (hyperinsulinism). QUESTION 7: What types of tests are run on each of the tube colors? Answer: The type of specimen collected is dependent on what tests are performed and how they are performed. Some tests are run on whole blood, some on serum, some on plasma, and some can be run on a variety of specimen types. It is how tests are performed, i.e., the methodology of analysis, that determines the specimen type. Refer to the following table for test tube types and tests commonly performed on them. Page 8 of 35

9 Tube Color Black Blood culture bottles Gold Gray Green Lavender Light Blue Navy Pink Red Red/Black Tan Yellow-ACD Yellow-SPS Examples of Tests Performed on Tube erythrocyte sedimentation rate (sed rate, ESR) color varies among manufacturers most chemistry (except therapeutic drugs) and serology tests glucose most chemistry tests, including therapeutic drugs CBC, WBC, H&H, platelet count, reticulocyte count, WBC differential, hemoglobin electrophoresis, some flow cytometry PT, PTT, TT, specific factor assays such as Factor VIII trace metals, lead blood type, crossmatch, antibody screen, antibody identification, direct antihuman globulin, indirect anti-human globulin most serology tests, such as RPR, mono, serum electrophoresis most chemistry (except therapeutic drugs) and serology tests lead HLA typing for paternity and organ transplant testing, some flow cytometry (solution B) blood culture for acid-fast bacteria, some viruses QUESTION 8: What do you recommend about drawing from the foot? Bilateral mastectomy patients? Amputees? Cancer patients with poor veins? Answer: 1. Foot veins: If routine sites for venipuncture are not available, blood can be obtained from foot and ankle veins. However, you must follow your facilities policies before collecting blood from these locations. Most healthcare facilities have a policy that the physician must be contacted for permission to use ankle and foot veins. This is because lower leg circulation may be impaired and venipuncture could lead to tissue death and/or blood clot formation. If physician approval is obtained, it is best to use 22 or 23 gauge needles and a syringe to obtain the specimens. These veins are small and may collapse when using vacuum systems. 2. Bilateral mastectomy patients: In the document Procedures for the Collection of Diagnostic Blood Specimens by Venipuncture, H3-A6, the CLSI states that a physician must be consulted before drawing blood from the side on which a mastectomy was performed. The standard says nothing about the length of time since the surgery or patients who have had bilateral surgeries. In a patient who has had bilateral mastectomies, foot or ankle veins should be considered. The physician then must be contacted for permission. If the physician requests blood be collected via venipuncture or Page 9 of 35

10 capillary puncture from an arm with a mastectomy, phlebotomy expert, Dennis Ernst, MT(ASCP), states that the permission be written so documentation is present should the patient suffer consequences and seek legal action. 3. Amputees: If an individual is missing one arm, the other should be used. If the other arm cannot be used, then permission to collect blood from a foot or ankle vein should be obtained. If the individual is missing all four limbs, arterial collection should be considered. Since arterial collection is outside the scope of practice for medical assistants and phlebotomists, other qualified healthcare professionals can collect these specimens. 4. Cancer patients with poor veins: A patient currently undergoing chemotherapy for cancer may have a vascular access device that can be used to collect blood specimens. Again, as blood collection from vascular access devices is outside the scope of practice for medical assistants and phlebotomists, other qualified healthcare professionals can collect these specimens. If a cancer patient does not have a vascular access device, all commonly used venipuncture sites should be evaluated. Collection should be performed with smaller gauge needles and syringes to avoid collapse of the vein from vacuum in tubes. Capillary puncture can also be considered. QUESTION 9: Who are CLSI, CAP, and TJC and how do they affect me? Answer: 1. CLSI ( Clinical Laboratory Standards Institute) is an organization that promotes the development and use of voluntary standards and guidelines in the healthcare community. They bring together experts in the field to research literature and develop recommendations for ways to provide quality patient testing. CLSI publishes standards on all aspects of laboratory testing, ranging from specimen collection of blood and urine to use of laboratory information systems to maintain and report laboratory test results. CLSI publishes specific standards for venipuncture, skin puncture, newborn screening, specimen transport, and specimen handling. Most laboratories use CLSI standards as references to develop policies and procedures. Many laboratory accreditation agencies require CLSI standards to be followed. 2. CAP (College of American Pathologists) voluntarily inspects laboratories performing patient care testing. A laboratory requests to be inspected by CAP to receive laboratory accreditation. They publish checklists, and to receive CAP accreditation, inspectors document that the laboratory meets the standards in the checklists. Checklists are updated as needed and inspections occur every other year. CAP relies heavily on the standards published by CLSI to determine checklist standards. The majority of specimen collection standards are found in the Laboratory General CAP checklist. The standards address items such employee competency documentation, patient identification, phlebotomy policies/procedures, and more. Because of its comprehensive nature, CAP accreditation documents that the laboratory provides a consistently high level of service. If a laboratory is CAP accredited, it has deemed status with the federal government, meaning that it is exempt (in most cases) from inspection by the Page 10 of 35

11 government to ensure compliance with the Clinical Laboratory Improvement Act of 1988 (CLIA 88). 3. TJC (The Joint Commission) voluntarily inspects hospitals, surgical centers, longterm care facilities, etc. As with CAP, The Joint Commission publishes standards and a healthcare facility must meet these standards to receive accreditation. Receiving Joint Commission accreditation documents that the facility consistently provides a high level of service. The Joint Commission also researches, develops, and publishes the National Patient Safety Goals. Policies and procedures regarding phlebotomy specimen collection, employee competency, and more are based on Joint Commission standards. Healthcare facilities that are accredited by The Joint Commission may not have to undergo mandatory state inspections. The Joint Commission inspects accredited healthcare facilities every months. QUESTION 10: Why would I use a butterfly needle and how do I use it? Answer: Butterfly is the informal name for a winged infusion set, also called a scalp needle set. It consists of a needle and tubing with plastic wings on either side of the needle and a luer adapter on the end of the tubing. Note: The collection set pictured below is attached to a tube holder. The needle is shorter than a routine venipuncture needle and the wings are grasped to assist with insertion and removal of the needle. A syringe or tube adapter is attached to the luer adapter at the end of the tubing. The needle sizes are 21-, 23-, and 25-gauge. Because nothing is directly attached to the needle, the angle of insertion can be very low. This is useful when collecting blood from superficial veins. Therefore, a butterfly with a 23- or 25-gauge needle is helpful when collecting blood from infants, children, elderly individuals, hand veins, and foot veins. There are two disadvantages to the use of butterfly needles: 1) drawing blood through a smaller gauge needle and the tubing increases the chance of hemolysis; and 2) studies have shown that butterfly needles account for the highest percentage of needlestick injuries. Therefore, extreme care must be used to avoid these issues when using a butterfly. Page 11 of 35

12 QUESTION 11: How do I do a blood culture? Why do they sometimes have to be drawn at different sites and/or different times? Answer: Important aspects of blood cultures follow. 1. Skin preparation: Skin antisepsis is a very important part of the blood culture collection procedure. Failure to follow sterile technique can introduce skin surface bacteria into the blood culture bottle and interfere with the interpretation of patient results. Because all microorganisms isolated from blood cultures must be reported by the laboratory, it is up to the patient s physician to determine if the organism is clinically significant or merely a contaminant. If an organism is misinterpreted as pathogenic, it could result in inappropriate treatment for the patient and additional expense. Blood culture specimens (bacteria, fungal, AFB, viral) must be collected before any other laboratory blood specimen. Cleansing of the venipuncture site prior to blood culture collection involves the use of a commercially prepared blood culture skin preparation kit. Some prep kits are one-step using 2% chlorhexidine gluconate mixed with 70% isopropyl alcohol as the antiseptic; others are two steps using 70% isopropyl alcohol followed by 2% tincture of iodine. Manufacturer instructions must be followed exactly to assure the skin is cleansed properly. This includes the methods used to cleanse the skin (back-and-forth scrub or concentric circles) as well as allowing the solutions to air-dry. NOTES: Chlorhexidine solutions should not be used on infants less than 2 months of age. In the event the patient is allergic to iodine, the venipuncture site should be cleansed first with soap and water then followed by two applications of alcohol. Each application of alcohol must be allowed to dry. 2. Blood culture bottles: Blood culture bottles vary by manufacturer. All contain quantities of media to assist the growth of microorganisms. The tops of blood culture bottles should be cleansed with alcohol prior to filling with blood. Antiseptics containing iodine should not be used to cleanse the bottle tops. The bottles from one manufacturer have long narrow necks that fit into the tube holder used for routine blood collection. The bottles are collected just as other vacuum tubes. However, the vacuum may draw more than 10 ml of blood, so the quantity of blood entering the bottle must be closely monitored by viewing the 5 ml marks on the bottle. Blood can also be entered into these bottles after being collected in a syringe using a blood transfer device. Blood culture bottles from other manufacturers have wider openings and are filled with blood by using a special wide mouth collection adapter. Blood can be directly collected into these bottles using a butterfly needle with the hub attached to the wide mouth adapter; or blood can be collected into a syringe and transferred to the bottles using a blood transfer device. Again, the volume of blood entering the bottles must be closely monitored to assure only 10 ml is placed in each bottle (for adults). Page 12 of 35

13 Blood cultures are collected in sets of two bottles: one for aerobic microorganisms and one for anaerobic microorganisms. Overfilling of bottles can lead to false positives; underfilling can lead to false negatives. 3. Volume of blood collected: Studies have shown that as few as one organism per milliliter of blood may be present. Therefore, sufficient quantities of blood must be collected to improve the chances of culturing the organism. A minimum of 10 ml per blood culture bottle for an adult is recommended. For an infant, 1 5 ml of blood is preferred in a pediatric blood culture bottle. In some circumstances, the infant s weight may indicate a smaller volume. If only 10 ml of blood can be collected, this quantity should be put into the AEROBIC blood culture bottle. Again, to optimize the chance of isolating organisms, blood cultures are often collected different times of day from different sites. The best practice is two sets per day, 30 minutes apart, from different sites. An exception is sometimes made for patients with suspected bacterial endocarditis. 4. Specimen collection: Specimens for blood cultures are always collected before any other specimens. The tops of the bottles should be cleansed with alcohol just prior to the venipuncture. The tourniquet should be placed on the patient arm, the venipuncture site selected, and the tourniquet released while the skin cleansing takes place. The skin cleansing antiseptic should completely air dry before the puncture. After the venipuncture site is dry, the tourniquet is reapplied. Under no circumstances should the venipuncture site be repalpated. After blood cultures have been collected on infants < than 2 months of age, cleanse the venipuncture site with sterile water or sterile saline to remove all residual iodine solutions. QUESTION 12: What is the difference between blood from a vein and blood from an artery? Answer: For most laboratory tests, the reference ranges for arterial and venous blood are similar. However, when blood gas results [hydrogen ion activity (ph), partial pressure of carbon dioxide (pco 2 ), partial pressure of oxygen (po 2 ), bicarbonate (HCO 3 ), and some others] are needed, arterial blood is required. Venous blood does not provide an accurate picture of oxygen and carbon dioxide status as the blood has already moved through the body s tissues. Therefore, oxygen has been used up and carbon dioxide produced. Blood tests are not routinely collected from an artery, as it is a more difficult and problem-prone procedure than venipuncture. QUESTION 13: What do I do if a patient faints? What other things can happen to a patient when his blood is drawn? Answer: Every facility that collects blood specimens must have a plan of action in place in the event a patient has an adverse reaction. It is always necessary to have someone help you when a patient has an adverse reaction. Page 13 of 35

14 When fainting occurs from blood collection, the reason is usually vasovagal syncope. Syncope is the medical term for fainting. The vagus nerve runs from the brain to the colon and when it is overstimulated, it causes the body's blood vessels to dilate and the heart to slow down. This anti-adrenaline effect decreases the ability of the heart to pump blood upward to the brain against gravity. Without blood flow, the brain turns off and fainting occurs. Signs that a patient might faint include sweating, pallor, dilated pupils, and shaking. The patient may state he/she is feeling light-headed and is seeing spots in front of his/her eyes. At this time, you should call for assistance. If a seated patient feels faint, the needle is removed from the arm and the patient s head placed between his/her knees. Tight clothing is loosened. If the patient loses consciousness, you and another individual should try to move the patient to the floor. Once the patient becomes conscious, he/she should stay in the collection area for at least 15 minutes. A wet towel applied to the patient s forehead and a glass of juice or water can help the patient feel better. Rare adverse reactions to blood collection include vomiting, seizure, and loss of bladder control. The healthcare facility should have procedures in place to handle all patient adverse reactions. QUESTION 14: How much blood can be safely taken from a baby or child? Answer: Removing more than 10% of an infant s total blood volume may result in shock and cardiac arrest. Healthcare facilities with infant and pediatric populations should determine the maximum amount of blood that can safely be drawn from one infant per day or total amount per one month of hospitalization. The determination is based on weight. An example of one laboratory s policy follows. GUIDE FOR MAXIMUM AMOUNTS OF BLOOD TO BE DRAWN FROM PATIENTS < 14 YEARS Weight (lbs) Max Amount To Be Drawn At Any One Time (ml) Page 14 of 35 Max Amount Of Blood (cumulative) To Be Drawn During A Given Hospital Stay Of 1 Month Or Less (ml)

15 QUESTION 15: What is the correct positioning of an arm for blood drawing? Answer: If possible, the patient s arm should be in a downward position to prevent backflow of blood from the tube into the vein. QUESTION 16: What are the requirements for drawing blood for blood bank procedures? Answer: An ABO-incompatible red blood cell (RBC) transfusion is the main cause of death from transfusion. Errors leading to ABO-incompatible blood transfusion can occur at any point in specimen collection, patient testing, and patient identification. Proper patient identification and specimen labeling is of utmost importance to the individual collecting specimens for blood bank testing. The patient s first name, last name, and unique identification number must appear on the patient s armband and the armband is thoroughly checked with the information on the transfusion request (lab test order). Any discrepancies between the patient wristband and test requisition must be resolved before the specimen can be collected. Most healthcare facilities will not accept pre-printed patient identification labels on tubes for blood bank testing. They request that the patient s first name, last name, unique identification number, date, time, and the phlebotomist s initials be handwritten on the label. Many healthcare facilities use a double system of patient identification for patients having blood bank testing. This involves placing another armband on the patient with the armband having another unique patient identifier. With this in place, there are two sets of identification information to use for patient identification. QUESTION 17: Explain protimes and Coumadin therapy. Answer: Coumadin is a brand name for the anticoagulant drug, warfarin sodium. It is given to individuals with a history of heart attacks, strokes, and deep vein/artery thrombosis to prevent the formation of blood clots. While taking this drug, patients must have their drug levels monitored closely to assure they get enough drug to prevent blood clots but not too much drug to make the patient bleed spontaneously. Coumadin therapy is monitored by testing protime (PT) levels. The Coumadin dose is adjusted to maintain an International Normalized Ratio (INR), which for most patients is 2 to 3. If the INR is less than 2, the patient s drug dosage is increased; if the INR is more than 3, the patient s drug dosage is decreased. QUESTION 18: What lab tests require fasting specimens? Answer: Tests that require fasting for accurate test results include glucose, triglycerides, total cholesterol, and other cholesterol fractions. Page 15 of 35

16 QUESTION 19: When is the right time to draw cardiac enzymes? Drug peak and trough levels? Answer: Cardiac Enzymes: Troponin and creatine phosphokinase (CK) are two recommended enzymes for detection of myocardial infarction (MI) or heart attack. Blood levels of troponin usually rise within 4-6 hours after a MI, reaching their highest levels within hours, and returning to normal within 10 days. CK levels generally rise between 4-8 hours after a MI, reaching their highest levels within hours, and return to normal within 3-4 days. Troponin and CK are usually ordered to be drawn every 4-6 hours for 1-2 days following a heart attack. Analysis of the series of results can confirm that a MI occurred as well as determine the severity of the attack. Therapeutic Drugs: Many medications must be monitored throughout the patient s drug treatment. Included in this group are bronchodilators, antibiotics, anti-seizure, antirejection drugs, and more. Certain drugs must be monitored as too much of the drug may cause toxic side effects while too little would not be effective in treating the disease/disorder. This is called therapeutic drug monitoring or TDM. Blood specimens for drug monitoring can be taken at two different times: during the drug's highest therapeutic concentration ("peak" level), or its lowest ("trough" level). Trough levels show sufficient therapeutic levels; whereas peak levels show poisoning (toxicity). Peak and trough levels should fall within the therapeutic range. If drug levels fall outside of the therapeutic range, dosages are modified. Different drugs are monitored at different times. It varies by drug, method of dosage (oral, IV, IM), patient age, patient organ function, etc. Generally, peak levels are usually obtained one to two hours after oral intake, approximately one hour after intramuscular (IM) administration (a shot in the muscle), and approximately 30 minutes after intravenous (IV) administration. Trough levels are usually obtained within 15 minutes of the next scheduled dose. QUESTION 20: What are preanalytical errors? Answer: The collection and analysis of blood specimens are subject to errors of many kinds, some of which are avoidable, others are not. It is the responsibility of the laboratory to minimize and take into account as many of these errors as possible. Errors are divided into three types: preanalytical, analytical, and post-analytical. Preanalytical errors are those errors that present themselves from the time of laboratory test order to the analysis of the specimen. The table on the following pages summarizes preanalytical errors related to specimen collection. Page 16 of 35

17 CAUSES OF PREANALYTICAL ERRORS Physiological Because constituents of the blood are affected by diet, exercise, and other factors, Factors Affecting the ideal time for collecting blood specimens is early in the morning while the body Basal State is still at rest and fasting, or approximately 12 hours after the last intake of food. This condition is known as the basal state. Factors affecting basal state follow. Age: Values for numerous blood components vary considerably with the age of the patient. For example, red blood cell and white blood cell values are higher in newborns than in adults. Some physiologic functions decrease with age in adults. For example, creatinine clearance, a kidney function test, naturally declines as a patient ages. Altitude: Decreased oxygen content of the air at higher altitudes causes the body to produce more red blood cells to fulfill the body s oxygen requirements. The higher the altitude, the greater the increase in red cell production. Red blood cell counts and related determinations such as hemoglobin and hematocrit will have higher reference ranges at higher elevations. Dehydration: Dehydration that occurs with persistent vomiting or diarrhea, for example, causes hemoconcentration, which can falsely increase some blood components such as red blood cell counts, enzymes, iron, calcium, and sodium. Diurnal (Daily) Variations: Many blood constituents show diurnal variation or normal fluctuations throughout the day. White blood cell counts, eosinophil counts, and iron levels are lower in the morning than in the afternoon. Cortisol levels are highest in the morning. Diet: Blood composition is significantly altered by ingestion of food. Glucose levels increase dramatically with the ingestion of food substances but should return to normal within two hours. Ingestion of fatty substances increases lipid content in the blood for anywhere from one to 10 hours or more. Some chemistry determinations should not be performed on non-fasting specimens, as the results will be inaccurate. Excessive fluid intake may cause decreased hemoglobin levels and later, electrolyte imbalance. Consumption of caffeine has been demonstrated to affect cortisol levels. Drugs: Many drugs alter physiologic functions. For an example, thiazide diuretics often cause increased calcium levels and may cause low potassium levels. It is not unusual for physicians to monitor levels of certain blood components while a person is receiving certain drug therapy. Other examples of drug alterations: chemotherapy drugs often lower white blood cell and platelet levels; acetaminophen (Tylenol) may affect liver and kidney tests; and steroids can cause pancreatitis and an increase in amylase and lipase. According to the College of American Pathologists, drugs known to interfere with blood tests should be stopped or avoided 4 to 24 hours prior to obtaining the blood sample for testing. Environment: Temperature and humidity are known to affect test values. Environmental factors associated with geographic location are accounted for when the laboratory establishes reference values. The laboratory monitors temperature and humidity to maintain specimen integrity. Exercise: Muscular activity, however moderate, will elevate the blood levels of a number of blood components such as lactic acid, creatinine, protein, and certain enzymes. Levels of these substances return to normal soon after the activity is stopped with the exception of the enzymes creatine phosphokinase (CK) and lactate dehydrogenase (LD), which may remain elevated 24 hours or more. Physiological Page 17 of 35

18 Factors Affecting Basal Statecontinued. Position: The position of a patient both before and during venipuncture influences blood composition. Going from a supine to standing position causes the water or plasma portion of the blood to filter into the tissues. This causes a decrease in plasma volume and increase in nonfilterable elements or substances such as proteins, iron, calcium, and blood cells. Pregnancy: Pregnancy causes physiologic changes in many body systems. Because of these changes, a number of laboratory test results are affected. For example, body fluid increases, which are normal during pregnancy, have a diluting effect on the red blood cells, leading to lower red blood cell counts. Gender: A patient s gender has a determining effect on the concentration of numerous blood components. Most differences are apparent only after sexual maturity. These differences are reflected in separate reference range values for male and female patients. For example, red blood cells, hemoglobin, and hematocrit reference ranges are higher in males. Venipuncture Patient Clinical Conditions Venipuncture Technical Conditions Stress: Emotional stress in the form of fear or anxiety has been shown to cause short-lived elevations in white blood cell counts, decreases in serum iron, and increases in adrenal hormone values. If blood is collected from venipuncture sites at or near patient areas with the conditions listed below, patient test results may be affected. edema burns mastectomy IV fluids The following factors related to technical performance of a venipuncture can lead to falsely elevated or falsely decreased test values. prolonged tourniquet application continuous clenching/releasing of patient fist skin site with antiseptic still wet anticoagulant-added tube containing insufficient quantity of blood hemolysis of blood specimen (numerous causes) incorrect handling and/or transport of blood specimen QUESTION 21: If a patient needs to have fasted for 12 hours before blood is drawn, does it matter if the fasting is during the night or during the day? Answer: For most routine tests, including lipids, no. However, there are some tests where the substances in the blood may vary at different times during the day. These include iron and various hormones. QUESTION 22: Could you explain more about getting blood from a syringe into a tube? Answer: A blood transfer device must be used to transfer blood from a syringe to the evacuated tubes. This provides a closed needleless system, as is required by OSHA, to minimize the risk of needlestick injury. As safety needles must be activated while inside the patient s vein or immediately upon removal, there is no sharp end available that can be used to puncture the tube stopper. Therefore, a blood transfer device is necessary. A blood transfer device resembles a tube holder. It contains a needle on the inside of the holder and a luer adapter on the other end. Refer to the following page for a graphic representation. Page 18 of 35

19 Tubes attach here Syringe attaches here To transfer blood from a syringe to a vacuum tube: 1. Activate the safety feature of the needle or winged collection set per manufacturer instructions, i.e., immediately upon removal from the patient arm or while still in the patient arm. 2. Remove and discard the needle from the syringe or winged collection set. 3. Put the syringe on the luer adapter of the blood transfer device. 4. Using the correct order of draw, place a vacuum tube on the needle inside the blood transfer device. Blood will enter the tube via vacuum. 5. After the tube is full, remove from the needle, invert to mix additives/anticoagulants as necessary. 6. Repeat steps 4 & 5 until all tubes have been collected. QUESTION 23: What type of diseases can I get from a needlestick? Answer: Theoretically, any disease that is spread via blood can be transmitted through a needlestick. These diseases include, but are not limited to, syphilis, human immunodeficiency virus (HIV), viral hemorrhagic fevers, cytomegalovirus, Epstein Barr virus, malaria, hepatitis B, hepatitis C, hepatitis D, Creutzfeldt Jakob Disease, Chagas disease, and numerous other bacterial, viral, and parasitic diseases. In the United States, the bloodborne diseases most likely to be transmitted via needlestick are hepatitis B, hepatitis C, and HIV. QUESTION 24: What specimens need to be protected from light and why? Answer: There are certain substances in the blood that break down when exposed to light. Therefore, if the specimen is exposed to light, test results will be falsely decreased. Examples of tests requiring protection from light include bilirubin, vitamin A, vitamin B 6, beta-carotene, and porphyrins. QUESTION 25: What do I do if a patient refuses to have his blood drawn? Answer: A healthcare worker who attempts a blood collection procedure without the patient s consent is violating this right and can be charged with assault and battery. If a patient refuses, you can gently try to persuade the patient ( Your doctor really needs these test results to treat you, etc). If that does not work, you must tell the patient s nurse that the patient has refused to have his/her blood drawn. QUESTION 26: What happens when peak/trough levels are not drawn on time? Answer: Inaccurate drug levels can occur when specimens are not collected at the indicated times. This can lead to incorrect treatment for the patient. Page 19 of 35

20 QUESTION 27: What do I do if a patient does not have an identification band? Answer: It is the responsibility of the phlebotomist to assure that the blood specimen is drawn from the individual designated on the request form. Always follow your healthcare facility s policies for patient identification. Recommendations for identifying patients without armbands follow. 1. Outpatient without armband a. Ask the outpatient to give his/her full name, address, birth date, and other identifying information. b. Compare this information with the information on the test request form. 2. Inpatient without armband: Do not draw blood until patient s nurse places an armband on the patient. 3. Emergency patients without armband: The unidentified emergency patient should be given a temporary but unique identification until positive identification can be made. Many healthcare facilities assign an identification using a Blood Bank identification system, even if the patient is not requiring blood transfusion. QUESTION 28: How many times can I stick a patient after an unsuccessful venipuncture? Answer: You must follow your healthcare facility s policies. Most facilities limit a phlebotomist to two attempts. QUESTION 29: How do I protect myself in isolation rooms? Answer: Each isolation room should be marked with a sign listing the type of isolation, the required personal protective equipment (PPE) to wear, and procedures to follow. Follow these instructions carefully to protect yourself. Do not take your phlebotomy tray into the isolation room. Take all necessary supplies in the room with you. All items taken into the room must be left there, with the exception of the tubes of blood. Tubes of blood should be placed in a sealable, leakproof plastic bag before exiting the room. QUESTION 30: What do I do if I have to draw blood on an unconscious patient? Answer: 1. Positively identify the patient by comparing identifiers on the patient s wristband to information on the test requisition. 2. Talk to the patient as you would a conscious patient. 3. Be prepared to have the patient move his/her arm during the venipuncture. Obtain assistance to hold the patient s arm or brace your body over the arm to keep it immobile. Be prepared to remove the needle and place pressure on the venipuncture site should the patient move violently. Page 20 of 35

21 QUESTION 31: How do I collect microsamples? Answer: Microsamples are collected by fingerstick (adult/child) or heelstick (infant). Capillary blood is collected into capillary tubes or micro-collection containers. At least one manufacturer makes a combination capillary tube and micro-collection container. Site Selection Finger For patients older than one year, the palmer surface of the middle or ring finger is the preferred site. It is not recommended to use the: the thumb as it has a pulse, the index finger as it may be more sensitive or callused, and the fifth (little) finger, as it has insufficient tissue depth to prevent bone injury. The puncture must be made on the palmer surface and not on the side or tip of the finger. The tissue on the side and tip of the finger is about half as thick as the tissue in the center of the finger. The puncture should be made across the fingerprints and not parallel to them as demonstrated in the following graphic. X X X Heel For infants less than one year of age, puncture to the lateral or medial plantar surface of the heel is generally used. The puncture must be made on the plantar surface medial to a line drawn posterior from the middle of the great toe to the heel, or lateral to a line drawn posterior from between the fourth and fifth toes to the heel (see below). Puncturing in areas other than these locations can damage the bones in the infant s heel. Page 21 of 35

22 The shaded areas indicated by the arrows are the appropriate sites for a heel puncture. The skin puncture on an infant s heel must be no deeper than 2.0 mm! Punctures deeper than this are associated with bone injury and infection. NOTE: Capillary blood should never be obtained from the: fingers on the side affected by a mastectomy (in the case of a bilateral mastectomy, consult the physician), fingers of a newborn or infant less than one year old, central area of an infant s heel (arch area), posterior curvature of an infant s heel, or ear lobes of an infant. In addition, capillary blood should not be obtained from swollen or previously punctured sites as accumulated tissue fluid may contaminate and dilute the specimen. Skin Puncture Procedure 1. Confirm the identity of the patient using at least two unique patient identifiers. 2. Position the patient. Adults and children can be seated in a chair suitable for skin puncture. However, it may be necessary to use a bed or reclining chair for positioning the patient. Infants should be placed on a flat surface such as an examination table. Always assure that the infant is safe from falling. 3. Verify the paperwork, select, and assemble the equipment and supplies. 4. Perform the appropriate hand hygiene and put on clean gloves. 5. Select the puncture site. 6. Cleanse the site with 70% isopropyl alcohol or other antiseptic agent as indicated by the manufacturer s instructions. 7. Allow the antiseptic agent to air dry so the antiseptic action can take effect. 8. Remove the sterile retractable puncture device from the packaging. 9. Inspect the device for flaws. 10. Hold the device firmly. 11. Hold the patient s finger or heel firmly to prevent sudden movement. 12. Position the device on the patient s skin as described in the manufacturer s instructions. 13. Notify children and adults of pending puncture. 14. Activate the puncture device. Page 22 of 35

23 15. Wipe away the first drop of blood with a dry gauze pad. NOTE: Refer to the manufacturer s instructions as, for some waived tests, the first drop of blood is acceptable for testing. 16. Micro-collection containers: Collect the specimen as described in the Manufacturer s instructions. General instructions follow. a. The order of collection differs from that of venipuncture. i. The EDTA (lavender top) tube is collected first to ensure adequate volume and optimal specimen for hematology tests. ii. Other additive tubes are collected next. iii. Plain tubes for serum collection are collected last. b. As applicable, allow the second drop of blood to form over the puncture site. c. Touch the tip of the micro-collection container to the drop of blood. Blood will flow into the container by capillary action. d. Hold the puncture site downward and gently apply periodic pressure to the surrounding tissue to maintain blood flow into the top of the micro-collection container and down the walls of the container until sufficient blood has been collected to reach the fill to line. e. If collecting an anticoagulated specimen, adequately mix the tube and blood during filling and according to the manufacturer s instructions. f. When specimen collection is complete, immediately cap the micro-collection tubes and re-mix any anticoagulated tubes thoroughly. g. Label the micro-collection tubes according to facility policies. 17. Capillary tubes a. Touch the end of a capillary tube to the blood drop. Blood will flow into the capillary tube by capillary action. b. Seal the capillary tube by placing the dry end into a sealing compound tray. c. Continue collecting capillary tubes until a sufficient quantity has been collected. d. Place all sealed capillary tubes into a red top tube and label the tube per facility instructions. 18. Scooping blood into the micro-collection container/capillary tube and/or milking the puncture site must be avoided as this may result in hemolysis or contamination of the specimen with tissue fluid. 19. Apply direct pressure to the puncture site with a clean gauze pad and slightly elevate the finger or foot above the heart. Apply pressure for two to three minutes or until there is no evidence of bleeding. 20. Label the specimen container to assure proper identification. 21. After bleeding has ceased, a bandage can be applied to patients older than two years of age. Bandages can pose a chocking hazard for those younger than two. 22. Appropriately dispose of used equipment and supplies. 23. Remove gloves and perform hand hygiene per your facility s policy. 24. Thank the patient for cooperating. QUESTION 32: What needle sizes are used for venipuncture and when should I use them? Answer: Routine venipuncture is generally performed with 21 gauge or 23 gauge needles. Unnecessary pain can be experienced with a needle larger than 21 gauge. Hemolysis is likely if needles with a gauge smaller than 23 are used. Almost all Page 23 of 35

24 venipunctures can be performed with a 21 gauge needle. Twenty-three gauge needles are useful for drawing blood on smaller and more fragile veins such as those of an infant/child, elderly individual, and veins not in the antecubital area (hand, foot, etc.). QUESTION 33: How do I do a bleeding time? Answer: A bleeding time is a test for platelet function. Many healthcare facilities have replaced the bleeding time test with an automated platelet function analyzer, which provides more standardized results. To perform a bleeding time, a small, standardized length and depth incision is made on the forearm. The puncture should be 1.00 mm deep and 5.0 mm in length for adults. Numerous manufacturers make spring-activated surgical steel blade devices that retract after the puncture has been made. The time is recorded until the bleeding stops. A recommended procedure follows. 1. Place the patient s arm on a steady support. 2. Locate an area to make an incision. The area should be about 5 cm below and parallel to the antecubital crease. Avoid surface veins, scars, bruises, and areas with edema. 3. Place a blood pressure cuff on the arm and inflate the cuff to 40 mm/hg. Hold this exact pressure for the length of the test. 4. Cleanse the area with antiseptic and allow to air dry. 5. Remove the incision device from the sterile package and take off the safety clip. 6. Gently rest the incision device on the patient s forearm so that a horizontal incision parallel to the antecubital crease will be made. 7. Push the incision device trigger and start a stopwatch. 8. Remove the device from the patient s arm. 9. After 30 seconds, touch an edge of blotting paper close to the incision but do not touch the paper directly to the incision. 10. Every 30 seconds touch the blotting paper close to the incision until bleeding stops. Stop the timer. 11. Remove the blood pressure cuff and cleanse the incision site with antiseptic. Apply a butterfly-type bandage and instruct the patient to keep the bandage on for 24 hours to minimize scaring. 12. While it varies among healthcare facilities, the reference range for bleeding times is generally 3-8 minutes. Most healthcare facilities recommend stopping the test if bleeding has not stopped by 15 minutes. QUESTION 34: What are the pros and cons of blood transfer devices? Answer: Pros 1. Provides a needleless system to transfer blood from syringe to tubes 2. Minimizes potential of needlestick 3. Meets OSHA requirements to select a safe needle device or needleless option whenever possible Cons: Adds an extra step to syringe collection Page 24 of 35

25 QUESTION 35: What are ACD solution A and ACD solution B tubes used for? Answer: Refer to question #1. QUESTION 36: What are some of the non-routine tube colors used for? Answer: Refer to question #1. QUESTION 37: How do I draw blood from a shunt or fistula on a kidney patient? Answer: Medical assistants and phlebotomists should never collect blood from a shunt or fistula. It is outside of the scope of practice for both professions. Only qualified individuals with documented training and competence should draw blood from these areas. QUESTION 38: What venipuncture equipment and materials go into sharps boxes? Answer: The following should be placed in sharps boxes: needles with attached tube holder (per OSHA, tube holders are only used once and needles are not removed) needles removed from syringes prior to the attachment of a blood transfer device (per OSHA, needles attached to syringes cannot be used to puncture the stoppers of vacuum tubes) lancets used for skin puncture vacuum tubes that have blood in them that will not be used for lab tests syringes with attached blood transfer devices needles opened but not used for venipuncture Items with blood on them, such as cotton balls, gauze, bandages, etc. should be disposed following your facility s policies. Most facilities have three types of disposal: sharps, biohazard but not sharps, and regular. QUESTION 39: Does the order of draw change if you use a butterfly or syringe? Answer: No, it does not. Refer to question #1. NOTE: If you are using a butterfly to draw a light blue top tube for coagulation studies, you must first collect a little blood into a discard tube. If this is not done, the volume of blood collected into the blue top tube will be incomplete due to the displacement volume in the winged infusion set tubing. Refer to the picture on the following page. Page 25 of 35

26 Displacement volume in winged infusion set tubing NOTE: All pictures are best viewed from the NCCT website or the Continuing Education CD-ROM. Photograph courtesy of Ann Gray, Inpatient Phlebotomy Supervisor, Physicians Reference Lab, Kansas City, Missouri QUESTION 40: How many capillary tubes are needed for one test? Should you draw extra? Answer: The number of capillary tubes that need to be collected is dependent on the laboratory test(s) being performed. It is always useful to draw extra capillary tubes; however, if the patient is an infant, this may not be possible due to volume restrictions. See question # 14. QUESTION 41: Are there ever false positive or false negative newborn screening tests? If yes, what happens next? Answer: Yes, there are false positive and false negative newborn screening tests. A positive newborn screening test is followed up by a repeat screening test and, if the repeat test is positive, more specific analysis of blood and urine. A false negative test may not be known until the patient becomes ill with symptoms for a disorder/disease and the screen is repeated. If a repeat test is positive, the original specimen is retrieved and retested to determine if there was a technical testing error. False positive and false negative tests can result from improper filter paper collection. If a filter paper circle becomes oversaturated with blood, too much of a substance may be present in the test sample area, resulting in a false positive. Too little blood in a filter paper circle may lead to a false negative. Therefore, it is critically important that each filter paper circle be filled with one drop of blood only. Refer to question #43. QUESTION 42: Is it really necessary to draw so much blood from a newborn for a blood culture? Answer: Refer to question # 11. QUESTION 43: What are the rules about filter paper collection? Answer: As described in question #41, false positive and false negative newborn screening tests may result from improper filter paper collection. Refer to the following table to assure a quality specimen. Page 26 of 35