MODULE 5 Capillary Flashcards
Why do we not must puncture any deeper than 2mm?
Deeper punctures risk injuring the bone, even in the safest puncture areas
Why do we NOT puncture areas between the imaginary boundaries?
The calcaneus may be as little as 2.4mm deep in this area
Why do we not puncture bruised areas?
Because it can be painful, and impaired circulation or byproducts of the healing process can negatively affect the specimen
Why do we not puncture in the arch and any other areas of the foot other than the heel?
Arteries, nerves, tendons, and cartilage in these areas can be injured
Why do we not puncture sites that are swollen
Excess tissue fluid in the area could contaminate the specimen
Why do we not puncture the posterior curvature of the heel?
The bone can be as little as 1mm deep in this area
Why do we not puncture through previous puncture sites?
This can be painful and can spread undetected infection
What are the safest areas to puncture?
Enumerate based on the safest to least
Medial
Lateral
Plantar
Heel
Why do we warm the site of puncture?
Warming increases blood flow up to sevenfold
Inflammation of the bone marrow and adjacent bone
osteomyelitis
Inflammation of the bone and cartilage due to infection
Osteochondritis
Why do we not puncture fingers of infants and children under 1 year of age
The amount of tissue and skin surface is too small that could lead to gone injury easily.
Also can leas to gangrene and infection
Why do we not puncture fingers on the same side of mastectomy without permission from the patient’s physician
The arm is susceptible to infection, and effects of lymphostasis can lead to erroneous results.
Why do we not puncture parallel to the grooves or lines of the fingerprint?
It makes blood collection difficult and the blood will run down the finger rather than form a rounded drop that is easier to collect
Why must not puncture the fifth/little/pinky finger?
The tissue between the skin surface is the thinnest and can lead to bone injury easily
Why must not puncture the index finger?
It is Usually more calloused and harder to puncture, more sensitive so the puncture can be more painful. It is usually used more and the patient may notice pain longer
Why do we not puncture the side or very tip of the finger?
Because it is in the central fleshy portion of the finger
Why do we not puncture the thumb?
Because it has 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
What is/are the common tests performed using microhematocrit tubes?
Manual Hct or packed cell volume (PCV)
What is coated to the tube for collecting Hct tube directly from a capillary puncture?
Ammonium heparin
What is coated to the tube when Hct tube is filled with blood from a lavender-top tube?
Plain or none
What color do the non-additive tubes have?
Blue
How man uL can microhematocrit tubes fill?
50uL to 75uL
What type of patients does capillary specimen collection is especially useful?
Pediatric
Why is capillary specimen collection useful for pediatric patients
Removing large quantities of blood can have serious consequences
Often referred as “bullets”
Microtubes or microcollection tubes
What are the types of sealants are used?
Plastic
Clay
Wax-type
Ability of a liquid to flow into a narrow space or thin tube without the use of external force such as gravity
Capillary action
What is the common capacity of CBG?
100uL
What additive is found in CBG?
Heparin
Warming device must not exceed to what temperature?
42C or 108F
What are the composition of capillary specimens?
Interstitial fluid
Intracellular fluid
Arterial blood
Venous blood
Capillary blood
Why is capillary blood contains a higher portion of arterial blood than venous blood?
Because arterial blood enters the capillaries under great pressure than the venous pressure at the exit of capillaries
Warming the site can increase what type pf composition of blood of capillaries will increase its flow?
Arterial
Tissue fluid from spaces between the cells?
Interstitial fluid
Fluid within the cells
Intracellular fluid
concentration of what is higher in capillary blood specimen?
Glucose
What analyte concentrations are lower in capillary blood
Bilirubin
Calcium
Chloride
Sodium
Potassium
Total protein
What are the following circumstances capillary puncture is appropriate choice for older children and adults?
Available veins are fragile, difficult to access, or must be saved for other procedures such as chemotherapy.
• Several unsuccessful venipunctures have been performed and the requested test can be collected by capillary puncture.
• The patient has thrombotic or clot-forming tendencies.
• The patient is apprehensive or has an intense fear of needles, and capillary collection is acceptable.
• The patient is extremely overweight, and veins are difficult to find.
• There are no accessible veins (e.g., the patient has intravenous [IV] lines in both arms or the only acceptable sites are in scarred or burned areas).
• To obtain blood for point-of-care testing (POCT) procedures such as glucose monitoring
For every 10mL of blood, ____ of iron is removed
4mg
Life may be threatened if more than ____ of blood volume is removed at once
10%
Aside for manual Hct, capillary blood is the preferred specimen for some tests, such as?
Newborn screening tests
True or false
Capillary puncture is appropriate for patients who are dehydrated or have poor circulation to the extremities than Venipuncture
False. It is not appropriate because it could cause shock since specimens may be hard to obtain and may not be representative of blood elsewhere
What are the tests that cannot be collected by capillary puncture?
Erythrocyte Sedimentation Rate (ESR)
Rate Methods
Coagulation studies (requiring plasma specimens)
Blood cultures
Tests requiring large volumes of serum or plasma
What is the order of draw for capillary puncture?
Blood gas specimen
EDTA specimen
Other additive specimen (Heparin)
Serum Specimen
Why is EDTA specimen collected first than other additive specimens?
Because other additive specimens can affect EDTA specimen by clotting
Why is CBG collected first?
To minimize exposure pf the blood to air and because clots in the specimen is not acceptable
Heelstick is used for?
Infants less than a year old
What is the position of infant for heel puncture?
Should be supine with the foot lower than the torso so the force of gravity can assist blood flow
Bluish in color usually from a shortage of oxygen in the blood
Cyanotic
Swollen with fluid, infected, or a recent previous puncture sites
Edematous
Puncture site must be free from:
Scar
Bruise
Rashes
Cyanotic
Edematous
What is the cite to puncture for adults and older children?
Palmar surface of the distal segment of the middle finger or ring finger
What is the puncture site for burned patients?
Earlobes
What is the puncture site for infants?
Heel
Safest area for heel puncture?
Most medial and lateral portion of the plantar surface of the heel
Warming the site can be accomplished by wrapping the site for how many minutes?
3-5 minutes
What is the CLSI recommended antiseptic for cleaning a capillary puncture site?
70% isopropanol
What antiseptic is not recommended to use to clean the site? And why?
Povidone iodine. Because it can greatly interferes with some tests- uric acid, phosphorus, and potassium
What tests will be affected when using povidone-iodine as antiseptic for cleaning the site?
Uric acid
Phosphorus
Potassium
What happens when we squeeze or use strong repetitive pressure?
Can result to hemolysis and tissue fluid contamination
Why do we not apply bandages to infants and children under 2 years of age?
They pose to choking hazard
What age is not recommended to use bandages?
Infants and children under 2 years of age
Brain dysfunction caused by toxic levels of bilirubin
Kernicterus
A treatment used for jaundice infants that can be placed under special lights to lower their bilirubin levels
Phototherapy
Testing of newborns to detect certain genetic, metabolic, hormonal, and functional disorders or conditions that can cause severe mental handicaps or other serious problems if not detected and treated early
Newborn/Neonatal Screening
What puncture is preferred for newborn screening?
Heel puncture
Disorder that is characterized by insufficient levels of thyroid hormones
Hypothyroidism
Inherited disorder characterized by lack of enzyme needed to convert milk sugar galactose into glucose needed by the body for energy
Galactosemia
Why must not the paper touch the surface of the heel for newborn screening?
It could allow smearing, blotting, and stoppage of blood flow and incomplete penetration of blood through the paper
Blood smears prepared from EDTA specimens should be made within ____ of collection to eliminate cell distortion caused by anticoagulants
1 hour
The drop of blood to the slide should be _____ in diameter?
1-2mm
What is the angle of spreader slide?
30 degrees
Probable cause:
Absence of feather
Spreader slide lifted before the smear was completed
Probable cause:
Holes in the smear
Dirty slide
Fat globules in the blood
Probable cause:
Ridges or uneven thickness
Too much pressure applied to the spreader slide
Probable cause:
Smear too thick
Blood drop too large
Spreader slide angle too steep
Patient has high red blood cell count
Probable cause:
Smear too short
Blood drop too small
Spreader slide angle too deep
Spreader slide pushed too quickly
Probable cause:
Smear too long
Blood drop too large
Spreader slide angle too shallow
Spreader slide pushed too slowly
Probable cause:
Smear is too thin
Blood drop too small
Spreader slide angle too shallow
Patient has a low hemoglobin
Probable cause:
Streaks or tails in feathered edge
Blood drop started to dry out
Edge of. spreader slide dirty or chipped
Spreader slide pushed through blood drip
Uneven pressure applied to spreader slide
True or false:
Blood smears are considered non biohazardous or infectious until they are stained or fixed
False. They are biohazardous or infectious until they are stained or fixed
What species caused malaria
Plasmodia
Thick blood smear is used for
Test for malaria
Progressive destruction of red blood cells in certain types of malaria causes?
Severe anemia
Type of specimen preferred for infants, young children, elderly patients, and patients with severe burn
Capillary blood
