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Phleb Ch 10
Phlebotomy Essentials Chapter 10
Question | Answer |
---|---|
A sterile, disposable, sharp-pointed or bladed instrument to puncture skin to obtain capillary blood specimen. | Lancet |
Small plastic tubes used to collect tiny amounts of blood obtained from capillary punctures (a.k.a. bullets). | Microcollection containers or microtubes |
When venous blood is obtained by syringe and put into a microcollection container what should you do? | The specimen must be labeled as venous blood because it may have different reference ranges. |
Disposable, narrow-bore plastic or plastic-clad glass capillary tubes that fill by capillary action are called what? | Microhematocrit tubes |
What are microhematocrit tubes used for? | Manual hematocrit (Hct), also called packed cell volume (PCV) |
Capillary Blood Gas (CBG) tubes are normally coated with this anticoagulant....... | Sodium Heparin |
What is a stirrer called in a CBG tube? | Fleas |
What is the purpose of a magnet with the CBG tube? | Mix the specimen |
Capillary blood more closely resembles what type of blood arterial or venous? | Arterial because it enters the capillaries under pressure |
Capillary specimens are a mixture of what 5 things? | Arterial, venous and capillary blood along with interstitial fluid and intracellular fluid |
What is interstitial fluid? | Fluid in the tissue spaces between the cells |
What is intracellular fluid? | Fluid within the cells |
Is the concentration of glucose higher or lower in capillary blood? | Higher |
Is total protein (TP), calcium (Ca2), and potassium (K+) concentrations higher or lower in capillary blood? | Lower |
What may cause potassium values to be falsely elevated in skin puncture specimens? | Fluid contamination or hemolysis of the specimen |
What are some indications for capillary puncture in an adult or older child? | Fragile veins must be saved for other procedures. Several unsuccessful venipunctures, and test can be collected by cap puncture. Pt. has tendency for clot/thrombosis. Needle phobia. No accessible veins. POCT for glucose. |
Capillary puncture is the preferred method of obtaining blood from infants and very young children for the follow reasons: | Small blood volume. Removing quantities of blood can lead to anemia, cardiac arrest. Life threatening >10% is removed at once or over short period of time. |
Tests that cannot be collected by capillary puncture are what ? | Erythrocyte sedimentation rate methods, coagulation studies that require plasma, blood cultures and tests that require large volumes of serum or plasma. |
Order of draw for capillary puncture? | Slide first Blood gas specimens (CBGs) EDTA (lavender, hematology) Other additive specimens (CBC, chemistry) Serum specimens (red) |
Where is the CLSI recommended site for capillary puncture on adults and children older than 1? | The palmar surface of the distal or end segment of the middle or ring finger of the nondominant hand. Should be in the central, fleshy portion of the finger, slightly to the side of center and perpendicular (across) the groves in the whorls. |
What is the spiral pattern on your fingertip called? | Whorls |
Why: Do not puncture fingers of infants and children under 1 y.o.? | The amount of tissue between the skin surface and bone is so small that bone injury is very likely. |
Why: Do not puncture finger on the same side as a mastectomy without consultation with the patient's physician? | The arm on the same side as a mastectomy is susceptible to infection, and effects of lymphostasis can lead to erroneous results. |
Why: Do not puncture parallel to the grooves or lines of the fingerprint (whorls)? | A parallel puncture will allow blood to run down the finger rather than form a rounded drop, and make collection difficult. |
Why: Do not puncture the fifth or little (pinky) finger? | The tissue between skin surface and bone is thinnest in this finger, and bone injury is likely. |
Why: Do not puncture the index finger? | It is usually more calloused and harder to puncture. It is also more sensitive so the puncture can be more painful; and, because that finger is typically used more, a patient may notice the pain longer. |
Why: Do not puncture the side or very tip of the finger? | The distance between the skin surface and the bone is half as much at the side and tip as it is in the central fleshy portion of the end of the finger. |
Why: Do not puncture the thumb? | It has a pulse, indicating an artery in the puncture area, and the skin is generally thicker and more calloused, making it difficult to obtain a good specimen. |
Osteomyelitis | Inflammation of the bone marrow and adjacent bone |
Osteochondritis | Inflammation of the bone and cartilage |
What depth will provide adequate blood flow in a newborn with risking bone injury? | 2.0mm or less |
According to CLSI the only safe areas for heel puncture on a newborn is where? | Plantar surface of the heel, medial to an imaginary line extending from the middle of the great toe to the heel or lateral to an imaginary line extending from between the fourth and fifth toes to the heel. |
If you warm the site for capillary puncture the specimen is described as what? | Arterialized because of the increase in arterial blood flow. |
Why: Do not puncture any deeper than 2.0mm? | Deeper punctures risk injuring the bone, even in the safest puncture areas |
Why:Do not puncture areas between the imaginary boundaries? | The calcaneus may be as little as 2.0mm deep in this area. |
Why: Do not puncture in the arch and any areas of the foot other than the heel? | Arteries, nerves, tendons, and cartilage in these areas can be injured |
Why: Do not puncture severely bruised areas? | It is painful, and impaired circulation or byproducts of healing process can negatively affect the specimen |
Why: Do not puncture the posterior curvature of the heel? | The bone can be as little as 1mm deep in this area |
Why: Do not puncture through previous puncture sites? | This can be painful and can spread previously undetected infection |
Why: Do not puncture a site that is swollen? | Excess tissue fluid in the area could contaminate the specimen |
Why can we not use povidone-iodine to clean skin puncture sites? | It greatly interferes with a number of tests, most notably bilirubin, uric acid, phosphorus and potassium |
Why do we wipe away the first drop of blood? | It is typically contaminated with excess tissue fluid and may contain alcohol residue that can hemolyze the specimen. There have been reports of isopropyl alcohol contamination causing errors in blood glucose testing. |
Why do we not use a scooping motion against the surface of the skin to collect blood? | Activates platelets, causing them to clump and can also hemolyze the specimen |
What causes increased bilirubin levels in newborns? | Overproduction or impaired excretion of bilirubin |
Overproduction of bilirubin occurs from accelerated red blood cell hemolysis associated with what disease? | Hemolytic disease of the newborn (HDN) |
A transfusion may be needed if bilirubin levels increase at a rate equal to or greater than what? | 5.0mg/dL per hour or when levels exceed 18.0 mg/dL |
How are bilirubin specimens collected? | Heel puncture. Collected in amber-colored microcollection containers. Specimens should be collected as close as possible to the time requested. Careful to avoid hemolysis which could falsely decrease bilirubin results. |
State mandated testing of newborns for the presence of certain genetic, metabolic, hormonal and functional disorders is called what? | Newborn/neonatal screening (NBS) |
The March of Dines recommends tat all newborns be screened for how many specific disorders? | 29 |
What 4 conditions are screened for by law? | Phenylketonuria (PKU) Hypothyroidism Galactosemia (GALT) Cystic Fibrosis (CF) |
Phenylketonuria | A genetic disorder characterized by a defect in the enzyme that breaks down the amino acid phenylalanine. |
Hypothyroidism | Insufficient levels of thyroid hormones. |
Galactosemia | Lack of the enzyme needed to convert the milk sugar galactose into glucose needed by the body for energy. |
Cystic Fibrosis | Genetic disorder affecting lungs and pancreas. Interferes with transport of chloride across cell membranes. Causes the body to produce thick, stick mucus secretions that build up in the lungs and other organs. |
How do you perform blood spot collection? | Heel puncture. Wipe away first drop. A large drop of free-flowing blood is applied to the center of the first circle. Touch the paper to the blood. DO NOT TOUCH HEEL. Completely fill the circle on both sides of the paper from one side to the other |
What do you do with the blood spot collection after it is collected? | Allow to air-dry in an elevated, horizontal position away from heat or sunlight. Specimens should not be hung to dry or stacked together before, during, or after the drying process, |
What is a blood film or smear (a drop of blood spread thin on a microscope slide) used for? | Manual differential (diff) |
Blood smears prepared from EDTA specimens should be made within how many hours? | 1 hour |
What is the correct angle for making a blood smear? | 30 degrees |
The thinnest area of a properly made smear is called what? | Feather |
Blood smears are considered biohazardous or infectious until when? | Until they are stained or fixed |
What is a thick blood smear used for? | Detect malaria |