Chapter 11

Question 1

What tube has its own special labeling

Answer 1

Blood bank (pink top)

Question 2

What is a cross match

Answer 2

Cross match to determine the compatibility between patient plasma and donor cells

Question 3

Blood donations are collected in

Answer 3

units

Question 4

Donor eligibility requirements

Answer 4

minimum age of 17
weigh at least 110 pounds
physical exam and medical history
written permission from the donor

Question 5

Lookback program

Answer 5

recipients can be notified if a blood donor is rejected for having a transmissible disease
federally mandated by the FDA

Question 6

Autologous donation

Answer 6

allows patient to donate for themself
requires physician order

Question 6

cell salvaging

Answer 6

Allows blood to be salvaged from sterile surgical field to be washed and reinfused to the patient

Question 7

blood culture

Answer 7

collected and cultured in micro for the detection of bacteria or other microorganisms
used when bacteremia or septicemia is suspected or a fever of unknown origin

Question 8

blood culture specimen requirements

Answer 8

Usually two to 4 collections drawn 30-60 minutes apart
* Minimum of 10 mL per collection
* Uses aerobic and anaerobic nutrient broth collection bottles
* Collect aerobic bottle if only enough blood for one bottle can be obtained
* Patients on antibiotics may require special collection bottles

Question 9

skin antisepsis

Answer 9

• Contamination from skin flora is major concern* Adequate antisepsis is critical
• Use a 30-60 second rub with iodine, chlorhexidine or povidone/70% ethanol
• Povidone sticks traditionally used or pads with benzalkonium chloride
• Start at the point of needle insertion and move in small circles outward in a 3-4 inch diameter area
• Chlorhexidine may be used in infants over age 2 months and those with iodine sensitivity

Question 10

Coagulation special collection

Answer 10

– A “clear” or discard tube is required for all coagulation tests except for PT or PTT
– A discard must is required when collecting with a butterfly because the air in the tubing displaces the vacuum in the collection tube
– Sodium citrate tubes must be filled until vacuum is exhausted
– Must have a 9:1 ratio of blood to anticoagulant
– NEVER pour two tubes together
– Some tests may require the specimen to be placed on ice

Question 11

How does a 2-hour postprandial glucose work?

Answer 11

Patient fasts for 10 hours.
Fasting glucose is collected. Patient ingests high glucose (100 g of glucose) meal.
Glucose level is collected 2 hours after the meal.
Glucose level should return to near fasting levels in 2 hours in non-diabetic patients

Question 12

How does a glucose tolerance test work?

Answer 12

– Patient eat a balanced diet containing 150g carbs daily and fasts for 12 hours before testing.
– Fasting glucose is obtained and patient drinks a beverage containing 75 g of glucose within 5 mins
– Glucose levels are drawn at 30 minutes, 1 hr, 2 hrs and 3 hrsand plotted on a curve
– Elevated levels at 2 hrs are diagnostic for diabetes

Question 13

Lactose tolerance test

Answer 13

Patient consumes lactose then 2 hr GTT is performed. Curves should resemble GTT curve. Flat curve indicates lactase deficiency

Question 14

Paternity/Parentage testing

Answer 14

Chain of custody must be maintained. Testing will include ABO typing, HLA typing and DNA profile of mom, baby and alleged father

Question 15

Therapeutic phlebotomy

Answer 15

– Performed similarly to blood donor collection. Performed on patients with polycythemia (overproduction of RBCs) and hemochromatosis (excess iron stores in the body)
– Usually around 500 mL are removed

Question 16

Therapeutic drug monitoring (tdm)

Answer 16

– Performed to assess the level of a specific drug to maintain a safe, effective level of the drug in the body
– May be random for medications taken daily
– Aminoglycoside drugs (gentamicin, tobramycin, vancomycin and amikacin) must be assayed at trough
– just before the dose is given – and peak levels
– Peak levels are assessed 30 minutes after an IV dose, 60 minutes after an IM dose, or 1-2 hours after an oral dose.
– Drug may be withheld if trough levels are elevated
– Some gel tubes may affect test results. Consult drug test package insert for specimen requirements

Question 17

toxicology specimens

Answer 17

tests for the presence of a drug or toxin frequently with some legal ramifications

Question 18

Forensic blood alcohol (ethanol) specimens

Answer 18

Specimen will be used in court; therefore, chain of custody must be maintained. May have to be collected in the presence of a law enforcement officer and may have to use their special collection kit

Question 19

Clinical blood alcohol (ethanol) specimens

Answer 19

Can not use alcohol as an antiseptic. Should be collected in glass tubes(plastic is too porous). Tube should be filled to prevent evaporation and the stopper must not be removed until testing is performed. Results are generally not admissible in court.

Question 20

Drug screening

Answer 20

usually urine specimen. Requires chain of custody. Performed for employment or sports participation. Most commonly looking for 7 major classes of drugs – amphetamines, barbiturates, benzodiazepines, cocaine, THC, opiates and phencyclidine (PCP). May also screen for propoxyphene(Darvocet) and methadone. May be on initial employment or can be done randomly. Room must be contained for the purpose of collecting urine drug screens

Question 21

Trace elements

Answer 21

– Tests for aluminum, arsenic, copper, lead, iron, & zinc
– Measured in small amounts
– Collected in specially cleaned trace element-free tube usually royal blue stopper

Question 22

Point of care testing

Answer 22

– Brings lab testing to location of patient
– Offers convenience to patient & short turnaround time
– Requires carrying out quality-control & maintenance procedures necessary to ensure that results are accurate

Question 23

Quality and Safety in POCT

Answer 23

– Waived vs. non-waived quality control checks
– Electronic quality control (EQC) built into POC instruments
– Specimen collection & handling not checked by EQC
– Daily external liquid QC for non-instrumented POCT
– POC instruments become possible fomites for disease

Question 24

Coagulation Monitoring by POCT

Answer 24

• Prothrombin time (PT) & international normalized ratio (INR)
• Activated partial thromboplastin time (APTT or PTT)
• Activated clotting time (ACT)
• Platelet function

Question 25

POCT instruments

Answer 25

• Cascade POC —ACT, APTT, PT/INR
• CoaguChek XS Plus —PT/INR
• GEM Premier 4000 —ACT, APTT, PT/INR
• i-STAT —ACT, PT/INR
• Verify Now —platelet function

Question 26

Arterial blood gases measured (POCT)

Answer 26

• pH
• Partial pressure of carbon dioxide
• Oxygen saturation
• Partial pressure of oxygen

Question 27

Electrolytes measured (POCT)

Answer 27

• Sodium
• Potassium
• Chloride
• Bicarbonate ion
• Ionized calcium

Question 28

Multiple-Test-Panel Monitoring by POCT

Answer 28

Commonly ordered stat tests such as blood gases, electrolytes, & hemoglobin

Question 29

Other Tests Performed by POCT

Answer 29

– Cardiac troponin T & I
– Lipid testing
– B-type natriuretic peptide
– C-reactive protein
– Glucose
– Glycosylated hemoglobin
– Hematocrit
– Hemoglobin
– Lactate
– Occult blood (guaiac)
– Pregnancy testing
– Skin tests
– Strep testing
– Urinalysis