PMLS 2 - Capillary Puncture

Capillary Puncture

It is done as an alternative to venipuncture

Capillary Puncture

Preferred method for infants

Capillary Puncture

Dermal puncture/ skin puncture

o Fingerstick puncture

o Heel stick puncture

Capillary Blood

Specimen for Capillary Puncture

warm it for 3 minutes

If all fingers are cold

70% isopropyl alcohol

Clean the puncture site with

not cold, cyanotic, bruised, cut, swollen, or has a rash

Choose the heel for the puncture site that is

45 -60° angle

Puncture the skin in one sharp, continuous movement, at a

positioning the puncture site in a downward angle

Blood flow is encouraged by

8-10 times

Cover the microtubes with the caps provided and mix additive tubes by inversions

Newborn/neonatal screening (NBS)

state 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

toxoplasma and HIV

Some states also screen for infectious agents, such as

o benefits to early diagnosis, \

o availability of accurate tests to confirm diagnosis, and

o better health as a result of early detection and treatment

Requirements for disorders to be included in NBS screening panels include:

CH (Congenital Hypothyroidism) and PKU (Phenylketonuria)

• Severe Mental Retardation

• Normal

CAH (Congenital Adrenal Hyperplasia)

• Death

• Alive and Normal

GAL (Galactosemia)

• Death of Cataracts

• Alive and Normal

G6PD

• Severe Anemia, Kernicterus

• Normal

Congenital Hypothyroidism

recommended when a baby is three days old

tested immediately before they leave

Infants who are discharged from the hospital earlier should be

risk of a false-positive result

brief rise in TSH levels before a baby is three days old

T4 is low and the TSH is elevated

a diagnosis of congenital hypothyroidism is confirmed

o thyroid stimulating hormone (TSH) and

o thyroxine (T4)

two newborn screening tests performed in blood to detect hypothyroidism:

TSH values are elevated and T4 values usually are low,

When the thyroid gland is defective, known as Primary CH,

Phenylketonuria

genetic disorder characterized by a defect in the enzyme that breaks down the amino acid phenylalanine, converting it into the amino acid tyrosine

results in increased phenylketones in the urine

Without intervention, phenylalanine, which is in almost all food

diet low in phenylalanine

PKU cannot be cured but normally can be treated with

rise to toxic levels and lead to brain damage and mental retardation

If left untreated or not treated early on, phenylalanine can

• shortly after an infant is born

• after the infant is 10 to 15 days old

PKU testing typically requires the collection of two specimens

1 in 10,000 to 25,000 births

The incidence of PKU in the United States is approximately

Galactosemia (GALT)

an inherited disorder characterized by lack of the enzyme needed to convert the milk sugar galactose into glucose needed by the body for energy

Within a week of birth, an infant with galactosemia will fail to thrive

due to anorexia, diarrhea, and vomiting unless galactose and lactose (lactose breaks down to galactose and glucose) are removed from the diet

the infant may starve to death.

Untreated Galactosemia,

Congenital adrenal hyperplasia (CAH)

group of genetic disorders that affect the adrenal glands, a pair of walnut-sized organs above the kidneys

Cortisol

adrenal glands produce important hormones, including

Cortisol

regulates the body's response to illness or stress

G6PD deficiency

an inherited condition

G6PD deficiency

It is when the body doesn't have enough of an enzyme called G6PD (glucose-6-phosphate dehydrogenase

G6PD

This enzyme helps red blood cells work correctly

hemolytic anemia

A lack of G6PD enzyme can cause

hemolytic anemia

red blood cells break down faster than they are made

Newborn screening tests

typically performed on a few drops of blood obtained by heel puncture

absorption onto circles printed on a special type of filter paper that is typically part of the NBS form

The blood drops are collected by

blood spots

The blood-filled circles are often referred to as

newborn screening specimens should be collected before it is started

If an infant requires a blood transfusion,

To fill the circles,

heel puncture is performed, and the first blood drop is wiped away in the normal manner

filter paper

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

not be allowed

paper must ______________ to touch the surface of the heel

original position of the paper must be maintained

blood must continue flowing until it completely fills the circle on both sides of the paper

Unfilled or incompletely filled circles

can result in inability to perform all required tests

one side of the paper only

Circles must be filled from _______________ 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

alcohol, formula, lotion, powder, and urine

Substances that have been identified as contaminants in newborn screening specimens include

air-dry in an elevated, horizontal position away from heat or sunlight

After collection, the specimen must be allowed to

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

Stacking

can result in cross-contamination between specimens, which also causes erroneous results

Wiping the first drop

removes excess tissue fluid and alcohol residue that could distort cell morphology

1 to 2 mm in diameter

The drop should be

1/2 to 1 inch

centered on the slide adjacent to the frosted end or __________ inch from one end of a plain slide

pusher or spreader slide

The second slide is called the

If blood is of normal thickness

30-degree angle will create a smear that covers approximately three fourths of the remaining area of the slide

red blood cell distortion may result

Never blow on a slide to dry it because

unfixed slides

are capable of transmitting disease and handle accordingly

blood film or smear

required to perform a manual differential (Diff)

manual differential (Diff)

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

blood film or smear

They are typically made in the hematology department from blood collected in an EDTA tube

1 hour of collection

Blood smears prepared from EDTA specimens should be made within ____________ to eliminate cell distortion caused by the anticoagulant.

leukocyte alkaline phosphatase (LAP) stain or score

requires four fresh peripheral blood (blood from an extremity) smears

hematologists

prefer blood smears made from blood that has not been in contact with EDTA. • When collected with other skin puncture specimens

collected first

blood smears should be _________ to avoid effects of platelet clumping

minimum of 2 minutes

To prepare a smear manually from an EDTA specimen, the tube of blood must first be mixed for a _________ to ensure a uniform specimen

plain capillary tube or pipet

used to dispense a drop of blood from the specimen tube onto the slide

DIFF-SAFE (Alpha Scientific, Malvern, PA)

allows a slide to be made from an EDTA tube without removing the tube stopper

biohazardous or infectious

Blood smears are considered ______________ until they are stained or fixed

Making a good blood smear

a skill that takes practice to perfect

Improperly made blood smears

may not contain a normal, even distribution of blood cells and can produce erroneous results

one half to three fourths

An acceptable smear covers about _____________ of the surface of the slide

feather

The thinnest area of a properly made smear, often referred to as the

feather

one cell thick and is the most important area because that is where a differential is performed

not acceptable

Smears that are uneven, too long (i.e., cover the entire length of the slide), too short, too thick, or too thin are

length and thickness of the smear

can usually be controlled by adjusting the size of the drop or the angle of the spreader slide

Dirt, finger- prints, or powder on the slide, or fat globules and lipids in the specimen

can result in holes in the smear

Thick blood smears

most often requested to detect the presence of malaria

malaria

a disorder caused by four species of parasitic sporozoan (types of protozoa) organisms called plasmodia

female anopheles mosquitoes

These organisms are transmitted to humans by the bite of infected

Symptoms of malaria

include serial bouts of fever and chills at regular intervals, related to the multiplication of certain forms of the organism within the red blood cells and the consequent rupture of those cells

severe anemia

The progressive destruction of red blood cells in certain types of malaria causes

malaria

diagnosed by the presence of the organism in a peripheral blood smear

both regular and thick blood smears

Diagnosis often requires the evaluation of

thick smear

Presence of the organism is observed most frequently in a

regular blood smear

identification of the species requires evaluation of a

STAT or at timed intervals

Malaria smears may be ordered

Malaria smears

most commonly collected just before the onset of fever and chills

size of a dime

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 __________

minimum of 2 hours

The smear is allowed to dry for a ___________ before staining with fresh diluted Giemsa stain

diluted Giemsa stain

a waterbased stain that lyses the red blood cells and makes the organism easier to see