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
