Phlebotomy Chapter 10 Flashcards

Questions and Answers

What can large quantities of blood removal in pediatric patients have?

serious consequences

Capillary collection is useful for whom?

pediatric patients

What is a sterile, disposable sharp pointed bladed instrument that punctures or makes an incision in the skin?

lancet

What vaporizes water in the skin to produce a small hole in the capillary bed?

laser lancet Signup and view all the answers

There is no risk of sharps injury with laser lancets.

True Signup and view all the answers

What are special small plastic tubes used to collect capillary puncture specimens?

microcollection containers or microtubes or bullets Signup and view all the answers

What are disposable narrow bore plastic or plastic clad tubes used for?

microhematocrit tubes Signup and view all the answers

Microhematocrit tubes are primarily used for what purpose?

manual hematocrit count Signup and view all the answers

What type of microhematocrit tubes are coated with ammonium heparin used for?

collecting hematocrit directly for a capillary puncture Signup and view all the answers

When are plain microhematocrit tubes used?

When hematocrit tube is filled with blood from a lavender top tube Signup and view all the answers

What does StatSpin Inc. provide for pediatric patients?

microcentrifuges for hematocrit tests Signup and view all the answers

Venous blood may have different reference ranges than what?

a capillary specimen Signup and view all the answers

What are long thin narrow bore capillary tubes called?

capillary blood glass tubes Signup and view all the answers

C B G tubes usually contain what?

sodium heparin; green top tube Signup and view all the answers

What are small metal filings or metal bars inserted into the tube after collection of a C B G called?

stirrers or fleas Signup and view all the answers

What is used to move the stirrer for mixing in a C B G tube?

a magnet with a hole in the center Signup and view all the answers

What do plastic caps on C B G tubes maintain?

anaerobic conditions in the specimen Signup and view all the answers

Warming devices are used to increase blood flow, especially in whom?

newborns for heelsticks Signup and view all the answers

What is the composition of capillary specimens?

mixture of arterial; venous; capillary blood; and interstitial fluid Signup and view all the answers

What is fluid in the tissue spaces between cells called?

interstitial fluid Signup and view all the answers

What is fluid within the cells referred to as?

intracellular fluid Signup and view all the answers

Capillary blood contains a higher proportion of what?

arterial blood Signup and view all the answers

Capillary blood most resembles what?

arterial blood Signup and view all the answers

In which type of blood is the concentration of glucose normally higher?

capillary blood Signup and view all the answers

Total protein, calcium, and potassium concentrations are lower in what?

capillary blood Signup and view all the answers

Tissue fluid contamination and hemolysis can falsely increase what?

potassium levels Signup and view all the answers

If a patient has fragile veins and is scheduled for chemotherapy, what method should be used for specimen collection?

capillary puncture Signup and view all the answers

What is the appropriate method of specimen collection on a patient with thrombotic tendencies?

capillary puncture Signup and view all the answers

Capillary puncture should be performed on patients with a fear of needles.

True Signup and view all the answers

Point of Care Testing (POCT) for glucose is performed with what?

capillary puncture Signup and view all the answers

If a patient has no accessible veins due to burns and IVs, how should a specimen be collected?

capillary puncture Signup and view all the answers

Capillary puncture is the preferred method of obtaining blood from whom?

infants and very young children Signup and view all the answers

Why is capillary puncture preferred for infants and small children?

they have small blood volume; venipuncture is difficult and may damage veins; risk of hemorrhage; thrombosis; infection; gangrene; risk of injury during restraint Signup and view all the answers

Capillary puncture should not be performed on patients with what conditions?

dehydration; or poor circulation Signup and view all the answers

Shock can cause what?

poor circulation Signup and view all the answers

What tests cannot be run on capillary specimens?

ESR; Coagulation plasma specimens or specimens that require large quantities of serum or plasma. Signup and view all the answers

Light blue top microtubes should not be used for what?

capillary specimens Signup and view all the answers

The order of draw for capillary specimens is different than what?

venipuncture order of draw Signup and view all the answers

What happens when puncturing skin releases tissue thromboplastin?

activates the coagulation process Signup and view all the answers

Capillary specimens must be collected quickly to minimize what?

platelet clumping and microclots Signup and view all the answers

Why are hematology tests drawn first for capillary puncture?

they are most affected by clotting Signup and view all the answers

Why are serum specimens collected last for capillary puncture?

they are supposed to clot Signup and view all the answers

What is the CLSI order of draw for capillary puncture?

CBGs; EDTA; other additive specimens; Serum specimens Signup and view all the answers

Specimens for newborn screening tests should be collected in what manner?

collected separately Signup and view all the answers

What is the preferred site for capillary puncture on adults and children over 1 year?

palmar surface of the distal or end segment of the middle or ring finger of nondominant hand Signup and view all the answers

Where should the puncture site on a finger be located?

in the central fleshy portion; slightly off center and perpendicular to the whorls of the fingerprint Signup and view all the answers

Finger pricks should not be performed on whom?

kids under 1 year old Signup and view all the answers

Why is a bone injury likely with finger pricks on babies under a year?

tissue between skin surface and bone is so small Signup and view all the answers

What should be done before performing finger pricks on the side of a mastectomy?

consulting with the doctor due to the effects of lymphostasis Signup and view all the answers

Where should you never perform a finger prick?

the pinky finger because tissue between skin and bone is the thinnest in this location Signup and view all the answers

Why should the index finger not be pricked?

it is often calloused and hard to puncture; it is the most sensitive and painful Signup and view all the answers

Never puncture the thumb because it indicates an artery.

True Signup and view all the answers

Why should you never puncture the very tip or the side of a finger?

the tissue is thin and bone injury is likely Signup and view all the answers

What is inflammation of the bone marrow and adjacent bone called?

osteomyelitis Signup and view all the answers

What is inflammation of the bone and cartilage referred to as?

osteochondritis Signup and view all the answers

What can puncture of the bone cause?

osteomyelitis or osteochondritis Signup and view all the answers

What is the heel bone called?

calcaneus Signup and view all the answers

What is the back of the heel called?

posterior curvature Signup and view all the answers

Why are deeper punctures more painful?

pain fibers increase in abundance below the capillary bed Signup and view all the answers

What is the CLSI proper heel puncture site?

on the medial or lateral plantar surface of the heel Signup and view all the answers

How deep should you never puncture the heel?

2.0 millimeters Signup and view all the answers

What antiseptic is recommended for capillary puncture site?

70% isopropanol Signup and view all the answers

Why should povidone iodine not be used to clean capillary puncture sites?

it interferes with tests such as bilirubin, uric acid, phosphorus and potassium Signup and view all the answers

What does BURPP stand for?

tests affected by povidone iodine Signup and view all the answers

What can residual alcohol on a venipuncture or capillary puncture site cause?

stinging and rapid hemolysis of red blood cells Signup and view all the answers

What is a puncture that opens when pressure is applied called?

gap puncture Signup and view all the answers

What should you always wipe away after puncturing?

the first drop, because it is usually contaminated with tissue fluid and alcohol Signup and view all the answers

Some POCT instruments may allow use of the first drop.

True Signup and view all the answers

How does a microhematocrit or narrow bore capillary tube fill automatically?

by capillary action Signup and view all the answers

What happens when scraping a capillary collection tube scoop against the skin?

activates platelets and hemolysis Signup and view all the answers

What can overfilling an anticoagulant collection tube cause?

microclots Signup and view all the answers

How should capillary blood gas specimens always be transported?

horizontal in ice slurry Signup and view all the answers

What does ice slurry prevent?

changes in pH in C B Gs and slows WBC metabolism Signup and view all the answers

What screening tests are required by law in 50 states?

phenylketonuria; galactosemia; hypothyroidism; and cystic fibrosis Signup and view all the answers

What is PKU?

phenylketonuria. Genetic disorder; defective enzymes can't break down amino acids and phenylalanine. Signup and view all the answers

What can PKU result in?

toxic levels of phenylalanine that leads to brain damage and mental retardation Signup and view all the answers

What is hypothyroidism?

congenital disorder low levels of thyroid hormones Signup and view all the answers

What is galactosemia?

GALT is an inherited disorder; is a lack of enzymes to convert milk sugar into glucose; leads to starvation Signup and view all the answers

What is cystic fibrosis?

primarily affects the lungs and pancreas; causes sticky mucus secretion build up in lungs and organs. Signup and view all the answers

When are most newborn screenings performed?

between 24 and 72 hours old Signup and view all the answers

How many different disorders can be detected in blood spot collection forms?

as many as 30 different disorders Signup and view all the answers

Blood smears made from EDTA tube should be made within how long?

1 hour of collection to eliminate cell distortion caused by the anticoagulant Signup and view all the answers

What does LAP test stand for?

leukocyte alkaline phosphatase score that requires 4 fresh blood smears from capillary puncture Signup and view all the answers

At what angle should the pusher slide in a blood smear be held?

a 30 degree angle Signup and view all the answers

What is the DIFF SAFE?

instrument used to poke the end of a collection tube so a drop of blood can be captured on a slide Signup and view all the answers

What is required for detecting malaria?

A thick smear of blood on a slide Signup and view all the answers

What is the absence of a feather in a blood smear due to?

spreader slide lifted before smear was completed Signup and view all the answers

What can cause holes in the smear?

dirty slide; fat globules in the blood; powder contamination Signup and view all the answers

What is ridges or uneven thickness in a smear usually due to?

too much pressure applied to the spreader slide Signup and view all the answers

What can a smear too thick be due to?

blood drop too large; spreader angle too steep; high RBC count Signup and view all the answers

What can a smear too short be due to?

blood drop too small; spreader angle too steep; spreader pushed too slow; high RBC count Signup and view all the answers

What can a smear too long be due to?

blood drop too large; spreader angle too shallow; spreader slide pushed too slow; low hemoglobin Signup and view all the answers

What can a smear too thin be due to?

blood drop too small; spreader angle too shallow; low hemoglobin Signup and view all the answers

What can streaks in the feathered edge of a smear be due to?

blood dried out; dirty or chipped spreader; spreader pushed through the blood drop; uneven pressure of spreader Signup and view all the answers

Study Notes

Key Terms and Definitions

Pediatric Blood Removal: Large quantities can lead to serious consequences for pediatric patients.
Capillary Collection: Particularly useful for pediatric patients, minimizing risk and discomfort.
Lancet: A sterile, disposable instrument used for skin punctures.
Laser Lancet: Vaporizes skin water, creating small holes in the capillary bed without damaging delicate capillaries.

Collection Tools and Techniques

Microcollection Containers: Plastic tubes used for collecting capillary specimens.
Microhematocrit Tubes: Narrow bore tubes used for hematocrit counts and collecting blood for specific tests.
C B G Tubes: Contain sodium heparin and require stirrers for mixing with collected blood samples.

Blood Composition Insights

Capillary Specimens: Composed of a mixture of arterial, venous, capillary blood, and interstitial fluid, resembling arterial blood.
Glucose Concentration: Normally higher in capillary blood compared to venous blood.
Potassium Levels: Can be falsely elevated due to tissue fluid contamination or hemolysis.

Patient Considerations

Capillary Puncture Preference: Recommended for patients with fragile veins, burns, IVs, and fear of needles; preferred method for infants due to their small blood volume.
Dehydration Risks: Capillary puncture should not be performed on dehydrated patients or those with poor circulation.
Needle Phobia: Capillary puncture is ideal for anxious patients.

Capillary Puncture Techniques

Order of Draw: Different from venipuncture; hematology tests drawn first due to sensitivity to clotting.
Heel Puncture Site: Should be on the medial or lateral plantar surface, not to exceed 2mm in depth.
Skin Preparation: 70% isopropanol is the recommended antiseptic; avoid povidone iodine for certain tests.

Newborn Screening Tests

Required Tests: Include phenylketonuria, galactosemia, hypothyroidism, and cystic fibrosis, typically performed between 24 and 72 hours after birth.
Detection of Disorders: Up to 30 disorders can be identified through blood spot collection forms.

Blood Smear Preparation

Timing: Blood smears from EDTA tubes should be prepared within 1 hour to prevent cell distortion.
LAP Test: Requires fresh blood smears for accurate results.
Common Errors: Thicker smears occur due to large blood drops; streaks and holes may indicate contamination or improper technique.

Health Risks and Injury Prevention

Bone Injury Risks: Especially prevalent in infants due to thin tissue; punctures can lead to osteomyelitis or osteochondritis.
Avoiding Sensitivity: Thumbs and calloused fingers should not be pricked due to sensitivity and potential discomfort.
Contamination Management: Importance of wiping the first drop of blood and managing residual alcohol at the puncture site.

Transport and Analysis

Capillary Blood Gases: Always transport specimens horizontally in ice slurry to maintain pH stability.
Microclots: Can occur from overfilling anticoagulant tubes, affecting sample quality.

Summary of Conditions

Galactosemia: Inherited disorder leading to milk sugar metabolism issues and potential starvation.
Cystic Fibrosis: Genetic disorder that affects the lungs and pancreas, resulting in mucus buildup.

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Description

Test your knowledge with these flashcards from Chapter 10 of Phlebotomy. This chapter highlights important concepts regarding blood collection methods and instruments used in pediatric patients. Each card focuses on key terms and their definitions for effective learning.