PMLS LECTURE (Finals)

What top tube should be collected for blood bank test?

▪ RED, LAVENDER, PINK

What are the things blood bank test are strict for?

Blood bank specimens require strict patient identification and specimen labeling procedures.

Possible errors from mislabeling or misidentification procedure for blood bank tests

An undetected error can result in administration of an incompatible blood product and the possibility of a fatal transfusion reaction.

One of the special ID bracelet

PDC Securline Blood Bank (Precision Dynamics Corporation, San Fernando, CA)

BLOOD TYPE, SCREEN, AND CROSS-MATCH

One of the most common tests performed by the blood bank. This test determines a patient’s blood type (ABO) and Rh factor (positive or negative).

BLOOD DONOR COLLECTION

involves collecting blood to be used for transfusion purposes rather than for diagnostic testing.

Age and weight requirement to donate blood

ages of 17 and 66 years and weigh at least 110 pounds.

Special requirement when blood donating for minors

must have written permission from their parents.

Special requirement when blood donating for adults over 66 of age

may be allowed to donate at the discretion of the blood bank physician

The anticoagulant and preservative CPD (citrate–phosphate–dextrose) or CPDA1(CPD plus adenine)

is typically used in collecting units of blood for transfusion purposes

LOOKBACK PROGRAM

requires notification to all blood recipients when a donor for a blood product they have received has turned positive for a transmissible disease. At that point, it is absolutely necessary that verification for all blood components previously collected and currently in inventory has been retrieved.

AUTOLOGOUS DONATION

is the process by which a person donates blood for his or her own use. This is done for elective surgeries when it is anticipated that a transfusion will be needed.

Benefits of Autologous donation

Using one’s own blood eliminates many risks associated with transfusion, such as disease transmission and blood or plasma incompatibilities

Autologous donation minimum time

Although blood is normally collected several weeks prior to the scheduled surgery, the minimum time between donation and surgery can be as little as 72 hours.

CELL SALVAGING

Aqueous solutions, plasma, and serum samples or banked erythrocytes often contain lysed RBCs that have released hemoglobin into the solution. For example, during some surgical procedures, the patient’s blood is salvaged, washed, and reinfused.

ly·sis

Rupture

agglutination

clumping

Results of a high free hemoglobin levels

indicates that too many red cells were destroyed during the salvage process and renal dysfunction could result if the blood were reinfused.

instrument to detect free hemoglobin

using point-ofcare instruments such as the HemoCue Plasma/Low Hemoglobin analyzer

the size of the needle and the location to puncture a donor unit

Donor units are normally collected from a large antecubital vein using a sterile 16- to 18-gauge needle.

The size of the bag for blood donor and what happens when a bag is partially filled?

The unit is normally filled by weight but typically contains around 450 mL of blood when full. Only one needle puncture can be used to fill a unit. If the unit only partially fills and the procedure must be repeated, an entire new unit must be used.

BLOOD CULTURES

help determine the presence and extent of infection as well as indicating the type of organism responsible and the antibiotic to which it is most susceptible. They are also useful in assessing the effectiveness of antibiotic therapy once treatment is initiated. This should be ordered on the basis of whether the patient has a condition in which bloodstream invasion is possible and not only when a patient experiences a fever of unknown origin (FUO).

bacteremia

bacteria in the blood

septicemia

microorganisms or their toxins in the blood

TIMING FOR BLOOD CULTURE DRAWING

are typically ordered immediately before or after anticipated fever spikes when bacteria are most likely to be present. The best chance for detecting bacteremia exists from ½ hour to 2 ½ hours prior to the next fever peak

How many specimens for blood culture?

The most recent literature of the American Society for Microbiology (ASM) states that two to four blood cultures are necessary to optimize the detection of bacteremia and fungemia. For optimum results, such specimens should be drawn 30 to 60 minutes apart.

BLOOD CULTURE MINIMUM VOLUME

10 ml is usually the minimum volume.

BLOOD CULTURE VOLUME FOR INFANTS AND YOUNGER CHILDREN

1% to 4% of the patient’s total blood volume,

bloood culture volume for For adults or people weighing more than 80 pounds.

20 to 30 mL per culture with a minimum of 10 mL per draw.

THREE OTHER TYPES OF ANTISEPTIC FOR BLOOD CULTURE

* 10% providone or 1-2% tincture of iodine
* Benzalkonium chloride
* Chlorhexidine gluconate/isopropyl alcohol

MEDIA INOCULATION METHODS

Inoculation is the purposeful introduction of bacteria into a sterile growth medium. A material is sterile when it has no living organisms present; contamination is the presence of unwanted microorganisms. Inoculation of media can occur several different ways: directly into the bottle during specimen collection or after collection as when blood has been collected in a syringe. • A third way is to use an intermediate collection tube to collect the sample for inoculation in the laboratory and not at the bedside.

antimicrobial (antibiotic) therapy

Presence of the antimicrobial agent in the patient’s blood can inhibit the growth of the microorganisms in the blood culture bottle.

fastidious antimicrobial neutralization (FAN) (bioMerieux) or antimicrobial removal device (ARD)

In such cases, the physician may order blood cultures to be collected in these forms in order to blood culture without it being contaminated.

antimicrobial removal device (ARD)

contains a resin that removes antimicrobials from the blood

fastidious antimicrobial neutralization (FAN)

contain activated charcoal, which neutralizes the antibiotic.

Postprandial (PP)

means after a meal.

2 HOUR POSTPRANDIAL GLUCOSE

a glucose test on a specimen collected 2 hours after a meal (2-hour PP) is an excellent screening test for diabetes and other metabolic problems.a glucose test on a specimen collected 2 hours after a meal (2-hour PP) is an excellent screening test for diabetes and other metabolic problems.

GLUCOSE TOLERANCE TEST

is used to diagnose problems of carbohydrate metabolism. The major carbohydrate in the blood is glucose, the body’s source of energy. This evaluates the body’s ability to metabolize glucose by monitoring the patient’s tolerance to high levels of glucose without adverse effects.

The two major types of disorders involving glucose metabolism

Hyperglycemia & Hypoglycemia

hyperglycemia

glucose level is increased

hypoglycemia

blood glucose levels are decreased

GTT preparation

* The patient must eat balanced meals containing approximately 150 grams (g) of carbohydrate for 3 days before the test and must fast for at least 12 hours but not more than 16 hours prior to the test.
* The patient is allowed to drink water during the fast and during the test to avoid dehydration and because urine specimens may be collected as part of the procedure.
* The patient is also not allowed to smoke or chew gum, as these activities stimulate the digestive process and may cause erroneous test results. The patient should receive both verbal and written instructions to ensure compliance.

GTT Graph reading

In normal patients, blood glucose levels peak within 30 minutes to 1 hour following glucose ingestion. The peak in glucose levels triggers the release of insulin, which brings glucose levels back down to fasting levels within about 2 hours and no glucose spills over into the urine. • Diabetics have an inadequate or absent insulin response; consequently, glucose levels peak at higher levels and are slower to return to fasting levels. If blood is not drawn on time, it is important for the phlebotomist to note the discrepancy so that the physician can take this into consideration.

A lactose tolerance test

is used to determine if a patient lacks the enzyme (mucosal lactase) that is necessary to convert lactose, or milk sugar, into glucose and galactose.

mucosal lactase

enzyme use to convert lactose into glucose and galactose

If the patient is lactose intolerant

the glucose curve will be flat, rising no more than a few mg/dL from the fasting level. Some individuals normally have a flat GTT curve (resulting in a false-positive result); it is then suggested that they have a 2-hour GTT performed the day before the lactose tolerance test so that results can be evaluated adequately.

Paternity testing

is performed to determine the probability that a specific individual fathered a particular child.

paternity testing preparation

Testing may be requested by physicians, lawyers, child support enforcement bureaus, or individuals. It is requires a chain-of-custody protocol and specific identifi cation procedures that may include fingerprinting. A photo identification document such as a passport is usually required. The mother, child, and alleged father are all tested. Blood samples are preferred for testing; however, buccal (cheek) swabs are increasingly being used.

THERAPEUTIC DRUG MONITORING

the testing of drug levels at specific intervals, is used in the management of patients being treated with certain drugs in order to help establish a drug dosage, maintain the dosage at a therapeutic (beneficial) level, and avoid drug toxicity.

THERAPEUTIC PHLEBOTOMY

involves the withdrawal of large volumes of blood usually measured by the unit (as in blood donation), or approximately 500 mL. It is performed by phlebotomists who have been specially trained in the procedure or in donor phlebotomy, as the procedure is similar to collecting blood from donors. It is used as a treatment for certain medical conditions such as polycythemia and hemochromatosis.

Polycythemia

is a disease involving the body’s overproduction of RBCs, which is detrimental to the patient’s health and the most common reason for performing therapeutic phlebotomy. The patient’s RBC levels are monitored regularly, usually by the hematocrit test. Periodic removal of blood when the hematocrit exceeds a certain level is used to help keep the patient’s RBC levels within the normal range.

Hemochromatosis

is a disease characterized by excess iron deposits in the tissues. It can be caused by a defect in iron metabolism or result from multiple blood transfusions or excess iron intake. Periodic removal of single units of blood from the patient gradually depletes iron stores because the body then uses the iron to make new RBCs to replace those removed.

TOXICOLOGY

is the scientific study of toxins (poisons).

Clinical toxicology

is concerned with the detection of toxins and treatment for the effects they produce.

Forensic toxicology

is concerned with the legal consequences of toxin exposure, both intentional and accidental.

what Toxicology tests examines?

blood, hair, urine, and other body substances for the presence of toxins, which often exist in very small amounts.

FORENSIC SPECIMENS

is to collect evidence that may help prove or disprove a link between individuals and/or between individuals and objects or places 

Chain of custody

requires detailed documentation that tracks the specimen from the time it is collected until the results are reported. The specimen must be accounted for at all times. If documentation is incomplete, legal action may be compromised. Information on the form also includes the time, date, and place where the specimen was obtained, along with the signature of the person from whom the specimen was taken. Patient identification and specimen collection take place in the presence of a witness, frequently a law enforcement officer, in which case protocol and packaging are completed by the officer before the specimen is sent to a crime laboratory for analysis. Any person who is involved in drawing a blood alcohol specimen for legal reasons can be summoned to appear in court.

BLOOD ALCOHOL (ETHANOL) SPECIMEN

test is commonly used to see if a person has been drinking alcohol recently. This test can find alcohol in your blood for up to 12 hours after drinking. It can also show the amount of alcohol that you drank. 

ANTISEPTIC USE FOR TESTING BLOOD ALCOHOL

70% isopropyl alcohol used for routine venipuncture site preparation or other alcohols such as methanol and ethyl alcohol cannot be used for a BAC collection. • Tincture of iodine contains alcohol and likewise should not be used to clean the site. The most frequently used antiseptics for ETOH specimen collection are aqueous povidone–iodine and aqueous benzalkonium chloride (BZK). If an alternative antiseptic is not available, regular soap and water can be used.

DRUG SCREENING

Testing is typically performed on urine rather than blood because it is easy to obtain and a wide variety of drugs or their metabolites (products of metabolism) can be detected in urine for a longer period of time

TRACE ELEMENTS

metals include aluminum, arsenic, copper, lead, iron, and zinc. These elements are measured in such small amounts that traces of them in the glass, plastic, or stopper material of evacuated tubes may leach into the specimen, causing falsely elevated test values.

LABELING AND HANDLING (NONBLOOD SPECIMEN)

* should include the type and or source of the specimen
* should be labeled with the same identifying information as blood specimens
* should be applied to the container, not the lid.

URINE

• Most frequently analyzed nonblood body fluid

TYPES OF SPECIMENS

Random, First morning , and the Midstream clean-catch

Random

most commonly received specimen because of its ease of collection and convenience for the patient. May be collected at any time. Useful for routine screening tests to detect obvious abnormalities.

First Morning

ideal screening specimens. Essential for preventing-false negative pregnancy tests and for evaluating orthostatic proteinuria. Concentrated

Midstream Clean-Catch

safe, less traumatic method for obtaining urine for bacterial culture and routine urinalysis. Less contaminated by epithelial cells and bacteria and therefore is more representative of the actual urine than the routinely voided urine

AMNIOTIC FLUID

Clear, almost colorless to pale-yellow fluid that fills the membrane that surrounds and cushions a fetus in the uterus

WHEN CAN WE COLLECT AMNIOTIC FLUID?

• Collected after 15 weeks gestation

TYPES OF TESTS FOR AMNIOTIC FLUID AND ITS TEMPERATURE

* Chromosome analysis: room temp
* Some chemistry tests: kept on ice

AMNIOTIC FLUID USES

• Used to detect problems in fetal development (neural tube defects; spina bifida) and assess fetal lung maturity

CEREBROSPINAL FLUID (CSF)

Clear, colorless liquid that surrounds the brain and spinal cord

THE THREE TUBES FOR CSF AND ITS TEMPERATURE

1st tube collected is used for chemistry an immunology (frozen), 2nd for microbiology studies (RT), 3rd for cell counts (refrigerated)

CEREBROSPINAL FLUID (CSF) uses

Primary reason for collecting CSF is to diagnose meningitis (brain abscess, CNS cancer and multiple sclerosis)

GASTRIC FLUID/ GASTRIC ANALYSIS

• Stomach fluid

GASTRIC FLUID/ GASTRIC ANALYSIS uses

Examines stomach contents for abnormal substances and measures gastric acid concentration to evaluate stomach acid production

THE TEST FOR GASTRIC FLUID

Basal gastric Analysis - Aspirating a sample of gastric fluid by means of a tube passed through the mouth and throat or nose and throat - Used to determine acidity prior to stimulation - after basal sample has been collected, a gastric stimulant (mc: histamine or pentagastrin) is administered IV and more gastric samples are collected.

NASOPHARYNGEAL SECRETION

• Comprised of the nasal cavity and pharynx

HOW IS NASOPHARYNGEAL COLLECTED?

NP spx: collected using sterile Dacron or cotton-tipped flexible wire swab. - Swab is inserted gently into the nose and passed into the nasopharynx - Gently rotated, then carefully removed, placed in a sterile tube containing transport medium, labeled, and delivered to the lab.

NASOPHARYNGEAL SECRETION uses

Detect presence of microorganisms causing diphtheria, meningitis, pertussis (whooping cough), and pneumonia

SALIVA

• Fluid secreted by glands in the mouth

SALIVA uses

Used to monitor: - hormone levels (salivary amylase) - detect alcohol - Detect drug abuse because it can be collected quickly and easily in a noninvasive manner

SEMEN (SEMINAL FLUID)

Sperm-containing thick yellowish-white fluid discharged during male ejaculation

HOW IS SEMEN COLLECTED AND MAINTAIN

Collected in a sterile or chemically clean containers and must be kept warm, protected from light, and delivered to the lab immediately. Semen should not be collected in a regular condom because it often contain spermicides (substances that kill sperm) that invalidate test results.

SEMEN (SEMINAL FLUID) uses

Assess fertility or determine the effectiveness of sterilization following vasectomy. Forensic or legal issues (criminal sexual investigations)

SEROUS FLUIDS

Pale yellow, watery, serum-like fluid found between the double-layered membranes enclosing the pleural, pericardial, and peritoneal cavities.

SEROUS FLUID TESTS

* EDTA : cell count or smears
* Heparin / Sodium fluoride : chemistry tests
* Nonanticoagulated : biochemical tests
* Sterile heparinized tube : cultures

(Mycobacterium tuberculosis)

* bacteria that causes TB: acid-fast bacillus
* sputum test: AFB culture
* First morning specimens : preferred
* Collected from a sputum and usually 1 hour after a meal to minimize the risk that the px will gag or vomit
* - Transported at RT and require immediate processing upon arrival in the lab to maintain spx quality.SP

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SWEAT

Chloride content in the diagnosis of cystic fibrosis, predominantly in children and adolescents under the age of 20

SWEAT uses

Can be used to detect illicit drug use. Sweat is collected on patches places on the skin for extended periods of time and then tested for drugs.

SWEAT TEST

CF px have abnormally high levels of chloride in their sweat (2-5x higher) - Transporting pilocarpine (a sweatstimulating drug) into the skin by electrical stimulation from electrodes placed on the skin, a process called iontophoresis

SYNOVIAL FLUID

Clear, pale-yellow, viscous fluid that lubricates and decreases friction in movable joints.

SYNOVIAL FLUID USES

Identify or differentiate arthritis, gout, and other inflame conditions.

SYNOVIAL FLUID tubes and tests

Collected in three tubes: -

* EDTA/Heparin : cell counts, crystal ID, and smear prep -
* Sterile tube : culture and sensitivity -
* Nonadditive tube : macroscopic appearance, chemistry, immunology tests, and to observe clot formation.

BUCCAL SWABS

\: less invasive, painless alternative to blood collection for obtaining cells for DNA analysis

HOW TO OBTAIN A BUCCAL SWABS

Gently massage mouth on the inside of the cheek with a special swab, • DNA is later extracted from the cells on the swab.

BONE MARROW

Site of blood cell production obtained by a physician only Hematology and Histopathology Department

BREATH SAMPLES

* C-Urea Breath Test – Helicobacter pylori
* Hydrogen Breath Test – Lactose intolerance

HAIR

• Trace heavy metal analysis • Detection of drugs of abuse