Unit 7 - Capillary Puncture Equipment and Procedures Flashcards
T/F
Drops of blood for testing can be obtained by puncturing or making an incision in the capillary bed in the dermal layer of the skin with a lancet, other sharp device, or laser.
T
Terms typically used to describe capillary puncture regardless of the actual type of device or method used to penetrate the skin.
Dermal puncture
Skin puncture
Specimens obtained are respectively referred to as?
Capillary puncture specimens
Dermal puncture specimens
Skin puncture specimens
T/F
With the advent of laboratory instrumentation capable of testing small sample volumes, specimens for many laboratory tests can now be collected in this manner.
T
Capillary specimen collection is especially useful for __________ patients in whom removal of larger quantities of blood can have serious consequences.
Pediatric
A sterile, disposable, sharp-pointed or bladed instrument that either punctures or makes an incision in the skin to obtain capillary blood specimens for testing.
Lancets or incision devices
T/F
Lancets are available in a range of lengths and depths to accommodate various specimen collection requirements.
T
T/F
Selection depends on the __________ to collect an adequate specimen without injuring bone.
AGE of the patient, collection SITE, VOLUME of specimen required, and the puncture DEPTH needed
T/F
An important OSHA required lancet safety feature is a permanently retractable blade or needle point to reduce the risk of accidental sharps injury.
T
Lancet used to perforate the skin with a __________ instead of a sharp instrument.
Laser lancets
Typically vaporizes water in the skin to produce a small hole in the capillary bed without cauterizing delicate capillaries.
Laser lancets
T/F
In using laser lancets, no sharp instrument is involved.
Therefore, there is no risk of accidental sharps injury, and no need for sharps disposal.
Both T
T/F
In using laser lancets, no sharp instrument is involved.
Therefore, there is no risk of accidental sharps injury, and no need for sharps disposal.
Both T
Used to collect the tiny amounts of blood obtained from capillary punctures.
Microcollection containers
They are often referred to as “bullets” because of their size and shape.
Microcollection containers
T/F
Some microcollection containers come fitted with narrow plastic capillary tubes to facilitate specimen collection.
T
T/F
Some microcollection containers come fitted with narrow plastic capillary tubes to facilitate specimen collection.
T
Most microcollection tubes have color-coded bodies or stoppers that correspond to color-coding of ETS blood collection tubes, and markings for minimum and maximum fill levers that are typically measured in __________.
microliters (μL)
Minimum and maximum fill levels of microcollection tubes.
250 μL – 500 μL
T/F
Sometimes venous blood obtained by syringe during difficult draw situations is put into microcollection containers. When this is done, the specimen must be labeled as venous blood. Otherwise, it will be assumed to be a capillary specimen, which may have different reference ranges.
T
Disposable, narrow-bore plastic or plastic-clad glass capillary tubes that fill by capillary action.
Microhematocrit tubes
Microhematocrit tubes typically hold __________ of blood.
50 to 75 μL
Microhematocrit tubes are used primarily for manual __________, also called __________.
Hematocrit (Hct); packed cell volume (PVC) determinations
Hematocrit tubes coated with __________, for collecting Hct tubes directly from a capillary puncture.
Ammonium heparin
Hematocrit tubes used when an Hct tube is filled with blood from a lavender-top tube.
Plain
Heparin tubes typically have a _____ or _____ band on one end.
Red or green
Nonadditive tubes have a _____ band.
Blue
Smaller microhematocrit tubes designed for use with special microcentrifuges, such as those available from StatSpin, Inc. (Norwood, MA), require as little as _____ μL of blood and are often used in infant and child anemia screening programs and pediatric clinics.
9
Come in small trays are used to seal one end of microhematocrit tubes.
Plastic or clay sealants
T/F
Traditionally, the dry end of the tube was inserted into the clay to plug it.
T
T/F
Because of safety concerns, it is now recommended that sealing methods be used that do not require manually pushing the tube into the sealant or products be used that measure Hct without centrifugation.
T
Long thin narrow-bore capillary tubes.
CBG collection tubes
T/F
CBG collection tubers are normally glass for safety and are available in a number of different sizes to accommodate volume requirements of various testing instruments.
plastic
The most common CBG tubes are _____ mm in length with a capacity of 100 μL.
100
A color-coded band identifies the type of anticoagulant that coats the inside of the tube; it is normally green, indicating __________.
Sodium heparin
Small metal filings, often referred to as “fleas” or small metal bars that are inserted into the tube after collection of a CBG specimen to aid in mixing the anticoagulant.
Stirrers
Both ends of a CBG tube are sealed immediately after specimen collection to prevent exposure to air, and a __________ is used to mix the specimen.
Magnet
T/F
The magnet typically has an opening in the center or side so that it can be slipped over the capillary tube and moved back and forth along the tube length, pulling the metal stirrer with it, and mixing the anticoagulant into the blood specimen.
T
Used to seal CBG tubes and maintain __________ conditions in the specimen.
Anaerobic
T/F
CBG tubes typically come with their own caps.
T
Occasionally used to make blood films for hematology determinations.
Microscope slides
Warming the site increases blood flow as much as __________.
Sevenfold
Important when performing heelsticks on newborns.
Warming devices
To avoid burning the patient, the devices provide a uniform temperature that does not exceed __________.
42°C
T/F
A towel of diaper dampened with warm tap water can also be used to wrap a hand or foot before skin puncture.
T
T/F
Care must be taken not to get the water so hot that it scalds the patient.
T
Capillary specimens are a mixture of arterial, venous, and capillary blood, along with _________ and _________ from the surrounding tissues.
Interstitial and intracellular fluid
Fluid in the tissue spaces BETWEEN the cells.
Interstitial fluid
Fluid WITHIN the cells.
Intracellular fluid
Because arterial blood enters the capillaries under pressure, capillary blood contains a higher proportion of __________ blood than _________ blood and therefore more closely resembles __________ blood in composition.
Arterial; venous; arterial blood
This is especially true if the area has been warmed, because warming increases _________ flow into the area.
Arterial
Because the composition of capillary blood differs from that of venous blood, reference (normal) values may also differ.
T
The concentration of __________ is normally higher in capillary blood specimens.
Glucose
The concentration of __________ is normally lower in capillary blood specimens.
Total protein (TP)
Calcium (Ca2+)
Potassium (K+)
Although potassium values are normally lower in properly collected skin puncture specimens, levels may be falsely elevated if there is __________ contamination or __________ of the specimen.
Tissue fluid contamination; hemolysis
T/F
A properly collected capillary specimen can be a practical alternative to venipuncture when small amounts of blood are acceptable for testing.
T
In adults and older children, available veins are fragile or must be saved for other procedures such as __________.
Chemotherapy
T/F
In infants, when several unsuccessful venipunctures have been performed and the requested test can be collected by capillary puncture.
F
Capillary puncture can be an appropriate choice for adults and older children when the patient has __________ tendencies.
Thrombotic or clot-forming
T/F
Capillary puncture can be an appropriate choice for adults and older children when the patient is apprehensive or has intense fear of needles.
T
T/F
Capillary puncture can be an appropriate choice for adults and older children when there are accessible veins like the patient has IVs in both arms or the only acceptable sites are in scarred or burned areas.
F
T/F
Capillary puncture can be used for adults and older children to obtain blood for POCT procedures such as glucose monitoring.
T
T/F
Capillary puncture is the preferred method of obtaining blood from infants and very young children if the infants have small blood volume.
T
Removing quantities of blood typical of venipuncture or arterial puncture in infants can lead to __________.
Anemia
According to studies, for every _____ mL of blood removed, as much as _____ mg iron is also removed.
10; 4
Large quantities of blood removed rapidly from infants can cause __________.
Cardiac arrest
Life is threatened if more than _____% of a patient’s blood volume is removed at once or over a short period.
10%
T/F
Obtaining blood from infants and children by venipuncture is difficult and may damage veins and surrounding tissues.
T
Puncturing deep veins can result in which of the following?
A. Hemorrhage
B. Venous thrombosis
C. Infection
D. Gangrene
E. All of the above
E
T/F
An infant or child can be injured by the restraining method used while performing a venipuncture.
T
The preferred specimen for some tests, such as newborn screening tests.
Capillary blood
T/F
Capillary puncture is generally not appropriate for patients who are dehydrated or have poor circulation to the extremities from other causes, such as shock, because specimens may be hard to obtain and may not be representative of blood elsewhere in the body.
T
T/F
Erythrocyte sedimentation rate methods, coagulation studies that require plasma specimens, blood cultures, and tests that require large volumes of serum or plasma can be performed on very small quantities of blood, and a wide selection of devices are available to make collection of skin puncture specimens relatively safe and easy.
F
T/F
Although light blue top microtubes are available from some manufacturers, they are not to be used for capillary specimens.
T
T/F
Light blue top microtubes are intended to be used for venous blood collected by syringe in difficult draw situations.
T
T/F
Order of draw for collecting multiple specimens by capillary puncture is the same as venipuncture.
F
Puncturing the skin releases tissue __________.
Thromboplastin
It activates the coagulation process in the blood drops.
Thromboplastin
T/F
Specimens must be collected quickly to minimize the effects of platelet clumping and microclot formation and to ensure that an adequate amount of specimen is collected before the site stops bleeding.
T
Specimens are collected first because they are most affected by the clotting process.
Hematology specimens
Specimens are collected last because they are supposed to clot.
Serum specimens
The CLSI order of draw for capillary specimen.
- Blood gas specimens (CBGs)
- EDTA specimens
- Other additive specimens
- Serum specimens
T/F
Specimens for newborn screening tests should be collected separately.
T
Step 1
Review and accession test request
Step 2
Approach, identify, and prepare patient
Step 3
Verify diet restrictions and latex sensitivity
Step 4
Sanitize hands and put on gloves
Step 5
Position the patient
T/F
Position is important to patient comfort and the success of specimen collection.
T
T/F
For finger punctures, the patient’s arm must be supported on a firm surface with the hand extended and palm up.
T
T/F
A young child is typically held in the lap by a parent or guardian who restrains the child with one arm and holds the child’s arm steady with the other.
T
For heel punctures, an infant should be in __________ position with the foot __________ than the torso so the force of gravity can assist blood flow.
supine; lower
Step 6
Select the puncture or incision site
General site selection criteria include which of the following?
A. Warm
B. Pink or normal color
C. Free of scars, cuts, bruises, or rashes.
D. Cyanotic, edematous and infected.
E. A, B, and C only
E
T/F
Swollen or previously punctured sites should be avoided, because accumulated tissue fluid can contaminate the specimen and negatively affect test results.
T
T/F
Specific locations for capillary puncture include fingers of infants and heels of adults.
F
Recommended site for capillary puncture on adults and children older than 1 year is the palmar surface of the distal or end segment of the __________ finger of the __________ hand.
Middle or ring; nondominant
The puncture site should be in the central, fleshy portion of the finger, slightly to the side of the center and __________ to the grooves in the whorls of the fingerprint.
Perpendicular
T/F
Some texts refer to the end segment of the finger as the distal phalanx.
T
T/F
Some texts refer to the end segment of the finger as the distal phalanx.
T
T/F
Capillary puncture is okay to be performed on the fingers or earlobes of newborns or other infants under 1 year of age.
F
T/F
Do not puncture fingers of infants and children under 1 year of age.
T
T/F
In infants and children under 1 year of age, the amount of tissue between skin surface and bone is so small that bone injury is very likely.
T
T/F
In infants and children under 1 year of age, the amount of tissue between skin surface and bone is so small that bone injury is very likely.
T
Complications of finger puncture in newborns.
Infection and gangrene
T/F
Do not puncture fingers on the same side as a mastectomy without consultation with the patient’s physician.
T
The arm on the same side as a mastectomy is susceptible to infection, and effects of __________ can lead to erroneous results.
Lymphostasis
T/F
Do not puncture parallel to the grooves or lines of the fingerprint.
T
T/F
A parallel puncture will allow blood to run down the finger rather than form a rounded drop, and make collection difficult.
T
T/F
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.
T
T/F
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.
T
T/F
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.
T
T/F
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.
T
T/F
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.
T
T/F
The heel is the recommended site for collection of capillary puncture specimens on infants less than 1 year of age.
T
T/F
It is important to perform the puncture in an area of the heel where there is little risk of puncturing the bone.
T
Puncture of the bone can cause painful __________, as a result of infection.
Osteomyelitis or osteochondritis
Inflammation of the bone marrow and adjacent bone.
Osteomyelitis
Inflammation of the bone and cartilage.
Osteochondritis
Heel bone of small or premature infants.
Calcaneus
Calcaneus or heel bone of small or premature infants may be as little as _____ mm below the skin surface on the plantar or bottom surface of the heel and half that distance at the posterior curvature of the heel.
2.0
__________ increase in abundance below the capillary bed, so deeper punctures are more painful.
Pain fibers
T/F
To avoid puncturing bone the only safe areas for heel puncture are on the 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.
T
Step 7
Warm the site if applicable
Warming increases blood flow up to sevenfold and, except for _____ levels, does not significantly alter results of routinely tested analytes.
PaO2
T/F
Increased blood flow makes specimens easier and faster to obtain and reduces the tendency to compress or squeeze the site, which can contaminate the specimen with tissue fluid and hemolyze red blood cells.
T
The increase is caused by arterial flow into the area, a specimen obtained from a warmed site is described as being __________.
Arterialized
T/F
Warming the site is essential when collecting capillary pH or blood gas specimens.
T
T/F
Warming is typically recommended for heelstick procedures because infants normally have high red blood cell counts and other factors that result in relatively thick blood that flows slowly.
T
T/F
Warming may also be required before fingersticks when patients have cold hands.
T
Warming can be accomplished by wrapping the site for _____ minutes with a washcloth, towel, or diaper that has been moistened with comfortably warm water or using a commercial heel warming device.
3 to 5 minutes
The temperature of the material used to warm the site must not exceed 42°C (___°F) because higher temperatures can burn the skin, especially the delicate skin of an infant.
108°F
Step 8
Clean and air-dry site
T/F
The collection site must be cleaned with an antiseptic before puncture, so that skin flora do not infiltrate the puncture wound and cause infection
T
Microoganisms of the skin.
Skin flora
Recommended antiseptic for cleaning a capillary puncture site.
70% isopropanol
Which of the following is affected when povidone-iodine is used to clean skin puncture sites?
A. Bilirubin
B. Uric acid
C. Phosphorus
D. Potassium
E. All of the above
E
T/F
After cleaning, allow the site to air-dry to ensure maximum antiseptic action and minimize the chance of alcohol contamination of the specimen.
T
T/F
Residual alcohol, can cause stinging sensation, causes rapid hemolysis of red blood cells and it has also been shown to interfere with glucose testing.
T
Step 9
Prepare equipment
Gloves are put on at this point if not put on in step 4, “sanitize hands and put on gloves”.
Step 9: Prepare Equipment
T/F
Prepare equipment in view of the patient or guardian to provide assurance that it is new and being handled aseptically.
T
T/F
Verify lancet sterility by checking to see that packaging is intact before opening.
T
Step 10
Puncture the site and discard lancet
T/F
Grasp the patient’s finger between your nondominant thumb and index finger.
T
T/F
With very young children it is usually best to grasp __________ of the child’s fingers between your fingers and thumb (p. 330).
Three or four
T/F
In heel puncture, grasp the foot gently but firmly with your nondominant hand.
T
T/F
In heel puncture, encircle the heel by wrapping your index finger around the arch and your thumb around the bottom.
T
T/F
In heel puncture, wrap the other fingers around the top of the foot.
T
T/F
In heel puncture, place the lancet flat against the skin on the medial or lateral plantar surface of the heel.
T
Most manufacturers of heel incision devices recommend puncturing the heel at a __-degree angle to the length of the foot. This creates a “___” puncture.
90; gap
A puncture that opens when pressure is applied.
Gap puncture
T/F
Warn the patient or patient’s parent or guardian of impending puncture, and activate the release mechanism to trigger the puncture.
T
T/F
Remove the device from the skin immediately following puncture and discard it in a sharps container.
T
Step 11
Wipe away the first blood drop
T/F
Position the site downward and apply gentle pressure toward the site to encourage blood flow.
T
T/F
Wipe away the first drop of blood with a __________.
Dry gauze pad
Which of the following reasons why we should wipe away the first blood of drop?
A. The first drop is typically contaminated with excess tissue fluid.
B. May contain alcohol residue that can hemolyze the specimen.
C. Keeps the blood from forming a well-rounded drop.
D. All of the above
E
T/F
There have been reports that isopropyl alcohol contamination can cause errors in blood glucose testing.
T
T/F
Some POCT instruments may allow use of the first drop.
T
Step 12
Fill and mix tubes or containers in order of draw
T/F
Continue to position the site downward to enhance blood flow and apply gentle, intermittent pressure to tissue surrounding a heel puncture site or proximal to a finger puncture site.
T
T/F
Do not squeeze, use strong repetitive pressure, or “milk” the site, as hemolysis and tissue fluid contamination of the specimen can result.
T
T/F
Collect subsequent blood drops using devices appropriate for the ordered tests.
T
Collect slides, platelet counts, and other hematology specimens first to avoid the effects of ___________.
Platelet aggregation (clumping) and clotting
T/F
After collecting hematology specimens, collect other anticoagulant containers next, and serum specimens last.
T
T/F
To fill a collection tube or device, touch it to the drop of blood formed on the surface of the skin.
T
T/F
If making a blood film, touch the appropriate area of the slide to the blood drop.
T
T/F
A microhematocrit or narrow-bore capillary tube will fill automatically by “capillary” action if held in a vertical position above, or a horizontal position beside, the blood drop while touching one end to the blood drop.
T
T/F
While maintaining contact with the blood drop, the opposite end of the tube may need to be lowered slightly and brought back into position now and then as it fills.
T
T/F
Do not remove the tube from the drop or continually hold or tip the tube below the site. This can result in air spaces in the specimen that cause inaccurate test results.
T
T/F
When the tube is full, plug the opposite (or dry end) with
clay or other suitable sealant.
T
T/F
To fill a microcollection container or microtube, hold it upright just below the blood drop.
T
T/F
Touch the tip of the tube’s “scoop” to the drop of blood and allow the blood to run down the inside wall of the tube. The scoop should touch only the blood and not the surface of the skin. This allows blood to be collected before it runs down the surface of the finger or heel.
T
Do not use a ___________ motion against the surface of the skin and attempt to collect blood as it flows down the finger.
Scooping
Scraping the scoop against the skin activates __________, causing them to clump, and can also hemolyze the specimen.
Platelets
T/F
Tap microtubes gently now and then to encourage the blood to settle to the bottom.
T
Mix additive microtubes by gently inverting them __________ times.
8 to 10
T/F
If blood flow stops and you are unable to collect sufficient specimen, the procedure may be repeated at a new site with a new lancet.
T
T/F
Pay strict attention to fill levels of microtubes containing anticoagulants.
T
T/F
Excess anticoagulant in underfilled microtubes can negatively affect test results. Overfilling can result in the presence of microclots in the specimen or even complete clotting of the specimen.
T
Step 13
Place gauze and apply pressure
T/F
After collecting specimens, keep the site elevated while applying pressure.
T
T/F
An infant’s foot should be elevated above the body while pressure is applied.
T
Step 14
Label the specimen and observe special handling instructions
T/F
When labelling specimens, label the specimens with the appropriate information.
T
T/F
When labelling specimens, include nature and source of specimen according to facility policy.
T
T/F
When labelling specimens, label in view of the patient or guardian, and affix labels directly to microcollection containers.
T
T/F
Microhematocrit tubes can be placed in a nonadditive tube or an appropriately sized aliquot tube and identifying information written on the label; or follow laboratory protocol.
T
T/F
Ammonia should be handled cooling in crushed ice.
T
T/F
Cold agglutinin is transported at body temperature.
T
T/F
Bilirubin is sensitive to light.
T
Step 15
Check the site and apply bandage
T/F
If bleeding persists beyond 5 minutes, notify the patient’s nurse or physician.
T
If the bleeding has stopped and the patient is an older child or adult, apply a bandage and advise the patient to keep it in place for at least __________.
15 minutes
T/F
Do not apply bandages to infants and children under 2 years of age because they pose a choking hazard.
T
T/F
Bandage adhesive can stick to the paper-thin skin of newborns and tear it when the bandage is removed.
T
Step 16
Dispose of used and contaminated materials
T/F
Blood-soaked gauze, to be discarded in biohazard containers.
T
Step 17
Thank the patient, remove gloves, and sanitize hands
Step 18
Transport specimen to the lab
T/F
Prompt delivery to the lab protects specimen integrity and is typically achieved by personal delivery, transportation via a pneumatic tube system, or a courier service.
T
Neonates (newborns) are commonly tested to detect and monitor increased __________ levels caused by overproduction or impaired excretion of __________.
Bilirubin
Overproduction of bilirubin occurs from accelerated red blood cell hemolysis associated with __________
Hemolytic disease of the newborn (HDN)
Impaired bilirubin excretion often results from temporary abnormal _____ function commonly associated with premature infants.
Liver
High levels of bilirubin result in __________.
Jaundice
T/F
Bilirubin can cross the blood–brain barrier in infants, accumulating to toxic levels that can cause permanent brain damage or even death.
T
Transfusion may be needed if levels increase at a rate equal to or greater than __________ per hour or when levels exceed __________.
5.0 mg/dL; 18.0 mg/dL.
T/F
Bilirubin breaks down in the presence of light.
T
T/F
Jaundiced infants are often placed under special ultraviolet (UV) lights to _____ bilirubin levels.
Lower
T/F
The UV light must be turned off when collecting a bilirubin specimen to prevent it from breaking down bilirubin in the specimen as it is collected.
T
T/F
Bilirubin specimens are normally collected by finger puncture.
F
To reduce light exposure, specimens are typically collected in __________ microcollection containers.
Amber-colored
T/F
Specimens must be collected carefully to avoid hemolysis, which could falsely decrease bilirubin.
T
T/F
Determining the rate of increase in bilirubin levels depends on accurate timing, specimens should be collected as close as possible to the time requested.
T
Mandated testing of newborns for the presence of certain genetic (inherited), metabolic (chemical changes within living cells), hormonal, and functional disorders that can cause severe mental handicaps or other serious abnormalities if not detected and treated early.
Newborn or Neonatal screening
Some states also screen for infectious agents, such as?
Toxoplasma and HIV
T/F
Requirements for disorders to be included in NBS screening panels include benefits to early diagnosis, availability of accurate tests to confirm diagnosis, and better health as a result of early detection and treatment.
T
The March of Dimes recommends that all newborns be screened for __ specific disorders, including hearing loss, for which there is effective treatment.
29
There are __ other conditions that are often identified during NBS for which there is currently limited information or no treatment.
25
Screening for which of the following is required by law in all 50 states and U.S. territories.
A. Phenylketonuria (PKU)
B. Galactosemia
C. Hypothyroidism
D. All of the above
D
Newborn screening tests, except __________ tests, are typically performed on a few drops of blood obtained by heel puncture.
Hearing
T/F
The blood drops are collected by absorption onto circles printed on a special type of filter paper that is typically part of the NBS form.
T
T/F
The blood-filled circles are often referred to as blood spots.
T
As many as __ different disorders can be detected in the blood spots on one form.
30
T/F
If an infant requires a blood transfusion, newborn screening specimens should be collected before it is started, as dilution of the sample with donor blood invalidates test results.
T
T/F
To fill the circles, heel puncture is performed, and the first blood drop is wiped away in the normal manner.
T
T/F
The filter paper is brought close to the heel, and a large drop of free-flowing blood is applied to the center of the first circle on the printed side of the paper.
T
T/F
The paper must not be allowed to touch the surface of the heel because this can result in smearing, blotting, and stoppage of blood flow, and incomplete penetration of blood through the paper.
T
T/F
The original position of the paper must be maintained and blood must continue flowing until it completely fills the circle on both sides of the paper.
T
T/F
Unfilled or incompletely filled circles can result in inability to perform all required tests.
T
T/F
Circles must be filled from one side of the paper only and by one large drop that spreads throughout the circle. Application of multiple drops or filling circles from both sides of the paper causes layering of blood and possible misinterpretation of results.
T
T/F
Do not contaminate the filter paper circles by touching them with or without gloves or allowing any other object or substance to touch them before, during, or after specimen collection.
T
Substances that have been identified as contaminants in newborn screening specimens include which of the following?
A. Alcohol
B. Formula
C. Lotion and powder
D. Urine
E. All of the above
E
Substances that have been identified as contaminants in newborn screening specimens include which of the following?
A. Alcohol
B. Formula
C. Lotion and powder
D. Urine
E. All of the above
E
T/F
After collection, the specimen must be allowed to air-dry in an elevated, horizontal position away from heat or sunlight.
T
T/F
Specimens should not be hung to dry or stacked together before, during, or after the drying process. Hanging may cause the blood to migrate and concentrate toward the low end of the filter paper and lead to erroneous test results on the sample.
T
T/F
Stacking can result in cross-contamination between specimens, which also causes erroneous results.
T
T/F
When dry, the requisition containing the sample is normally placed in a special envelope and sent to a state public health laboratory or other approved laboratory for testing.
T
T/F
Results are sent to the infant’s physician or other healthcare provider.
T
Required to perform a manual differential (Diff).
Blood film or smear
A drop of blood spread thin on a microscope slide.
Blood film or smear
A test in which the number, type, and characteristics of blood cells are determined by examining a stained blood smear under a microscope.
Manual differential (Diff)
May be performed as part of a complete blood count or to confirm abnormal results of a machine-generated differential or platelet count.
Diff
How many blood smears are normally prepared and submitted for testing?
2
Although a common practice in the past, today blood smears are rarely made at the bedside. They are typically made in the __________ department from blood collected in an _____ tube, either by hand or using an automated machine that makes a uniform smear from a single drop of blood.
Hematology; EDTA
Blood smears prepared from EDTA specimens should be made within __ hour of collection to eliminate cell distortion caused by the anticoagulant.
1
First step in preparing a blood smear.
Capillary puncture
T/F
Wiping the first drop of blood removes excess tissue fluid and alcohol residue that could distort cell morphology.
T
The drop should be _____ mm in diameter and centered on the slide adjacent to the frosted end or 1/2 to 1 inch from one end of a plain slide.
1 to 2 mm
Hold the blood drop slide between the thumb and forefinger of the nondominant hand. With the other hand, rest the second slide in front of the drop at an angle of approximately __ degrees.
30
The second slide is called the _____ or _____ slide and is held at one end, between the thumb and index finger in either a vertical or horizontal position.
Pusher and spreader
If blood is of normal thickness, a _____-degree angle will create a smear that covers approximately _____ of the remaining area of the slide.
30; 3/4s
T/F
Do not push down on the spreader slide because this creates lines and ridges and an unacceptable blood film.
T
T/F
Do not use ink because it may dissolve during the staining process.
T
T/F
Allow the blood films to air-dry and place them in a secondary container for transport.
T
T/F
Never blow on a slide to dry it because red blood cell distortion may result.
T
T/F
Unfixed slides are capable of transmitting disease and handle accordingly.
T
To prepare a smear manually from an EDTA specimen, the tube of blood must first be mixed for a minimum of _____ minutes to ensure a uniform specimen.
2
T/F
A heparinized capillary tube or pipet is then used to dispense a drop of blood from the specimen tube onto the slide.
F
T/F
Blood smears are considered biohazardous or infectious until they are stained or fixed.
T
An acceptable smear covers about __________ of the surface of the slide and has no holes, lines, or jagged edges.
1/2 to 3/4s
It should show a smooth transition from __________ when held up to the light. The thinnest area of a properly made smear, often referred to as the __________, is one cell thick and is the most important area because that is where a differential is performed.
Thick to thin; feather
T/F
Smears that are uneven, too long (i.e., cover the entire length of the slide), too short, too thick, or too thin are still acceptable.
F
T/F
The length and thickness of the smear can usually be controlled by adjusting the size of the drop or the angle of the spreader slide.
T
Which of the following can cause holes in the smear?
A. Dirt
B. Fingerprints, or
C. Powder on the slide
D. Fat globules and lipids
E. All of the above
E
T/F
A chipped pusher slide, a blood drop that has started to dry out, or uneven pressure as the smear is made can cause the smear to have ragged edges.
T
Smears are most often requested to detect the presence of malaria.
Thick smears
Malaria is a disorder caused by which of the four species of parasitic sporozoan organisms?
A. P. vivax
B. P. falciparum
C. P. malariae
D. P. ovale
E. All of the above
E
T/F
Malaria is diagnosed by the presence of the organism in a peripheral blood smear.
T
T/F
The progressive destruction of red blood cells in certain types of malaria causes severe anemia.
T
T/F
Diagnosis often requires the evaluation of both regular and thick blood smears
T
Smear used when a organism is observed most frequently.
Thick
Smear used for identification of the species.
Thin
T/F
Malaria smears may be ordered STAT or at timed intervals and are most commonly collected just before the onset of fever and chills.
T
T/F
To prepare a thick smear, a very large drop of blood is placed in the center of a glass slide and spread with the corner of another slide or cover slip until it is the size of a dime.
T
The smear is allowed to dry for a minimum of __ hours before staining with fresh diluted Giemsa stain.
2 hours
A water-based stain that lyses the red blood cells and makes the organism easier to see.
Giemsa stain
