Laboratory management in the pre-analytical stage Flashcards
What are the physiological Factors in the pre-collection period?
Diurnal Variation
Exercise
Diet
Stress
Posture
Age
Gender
These are the variation in test results when the patient was subjected for specimen collection at a certain time of the day
Diurnal Variation
In transient exercise what are the affected analytes and its effect on the laboratory result?
Alanine and Lactate
Increase
In long exercise what are affected analytes and its effect on the laboratory result?
Creatine kinase, Aldolase, Alanine aspartate, Lactate dehydrogenase
Increase
In a person who are a long distance athlete, what are the affected analytes and its effect on the laboratory result?
Gonadotropin and Sex steroids
Decrease
What are the affected analytes in general exercise? and effects on lab testing?
Creatine kinase
Alanine aspartate
Lactate dehydrogenase
Coagulation activation
Fibrinolysis
Increase
Chronic aerobic exercise effect on the laboratory result is ______ and what are the analytes affected?
Decrease of plasma concentration
Creatine kinase
Alanine aspartate
Alanine transferase
Lactate dehydrogenase
Analytes affected in 48 hour fasting
Serum bilirubin (Increase)
Analytes affected in 72 hour fasting in healthy women
Plasma glucose (Decrease)
Analytes affected in 72 hour fasting in healthy men
Triglycerides, Glycerol and Free fatty acids (INCREASE)
What is effect of eating meat on the laboratory result?
Increase Potassium, Triglycerides, Alkaline phosphatase and 5 HIAA
Intake of meat, fish, iron supplements, horseradish effect on the laboratory result?
False positive in occult blood test due to presence of peroxidase
What is the effect of general physiologic on the laboratory test?
Increase chylomicrons
It is a condition caused by stress, can general affect the acid-base balance of the body?
Hyperventilation
What are the types of stress and its affected analytes and effect on the laboratory result?
= General Stress It increases ACTH, Cortisol, and Catecholamines
= Mild Stress increases total cholesterol
= Mild Stress decreases HDL cholesterol
= Hyperventilation increases leukocyte count, serum lactate and free fatty acids
Upright position increases hydrostatic pressure that cause
- Decrease of plasma volume
- Increase of protein concentrations
Incorrect application of the tourniquet and fist exercise can
affect:
- Lactate concentration (false increase)
- serum enzymes
(Prolong tourniquet Application) - Proteins
- Protein-bound substances
a. Cholesterol
b. Calcium
c. Triglycerides
What are the 4 age group?
a. Newborn
b. Childhood to puberty
c. Adult
d. Elderly
(True or False)
Age of the patient has an effect on the plasma constituents
False (serum)
What are the analytes that are higher concentration in men than women after puberty?
- Alkaline phosphatase
- Aminotransferase
- Creatine kinase
- Aldolase
What are the lowers levels of analytes in women have than men?
- Magnesium
- Calcium
- Albumin
- Hemoglobin
- Serum iron – this can be attributed to the menstrual blood
loss - Ferritin
It increase levels of carboxyhemoglobin, plasma catecholamine and serum cortisol.
Tobacco smoking
Errors in specimen collection that must be considered by a MT during pre-analytical stage:
i. Misidentification of patient
ii. Mislabeling of specimen
iii. Short draws/wrong anticoagulant/blood ratio
iv. Mixing problems/clots
v. Wrong tubes/wrong anticoagulant
vi. Hemolysis/lipemia
vii. Hemoconcentration from prolonged tourniquet time
viii. Exposure to light/extreme temperatures
ix. Improperly timed specimens/delayed delivery to laboratory
x. Processing errors: incomplete centrifugation, incorrect log-in and improper storage.
Test order that are most error free?
Electronically
It is a lab test that is requested that is prone to clerical errors?
Writting
It is a laboratory test order that is only done during emergency cases?
Verbal Request
What is the most commonly observed collection-associated variable?
Presence of Hemolysis in sample
Hemolysis is expected to occur in the?
i. Transfixing of the vein
ii. Too small needle
iii. Expelling the blood vigorously into the tube
iv. Shaking or mixing the tubes vigorously
v. Performing blood collection before the alcohol has dried at the
collection site
Reasons for specimen rejection?
a. Hemolysis/lipemia
b. Clots present in an anticoagulated specimen
c. Non-fasting specimen when test requires fasting
d. Improper blood collection tube
e. Short draws, wrong volume
f. Improper transport conditions (ice for blood gases)
g. Discrepancies between requisition and specimen label
h. Unlabeled or mislabeled specimen
i. Contaminated specimen/leaking container
Conditions that must be considered prior to transporting of specimens
a. Stability of the constituents
b. Label of the specimen
c. Container of the specimen used for transport
d. Potential infectious materials in the specimen
e. Temperature
f. Transport time
What are the phases in specimen processing?
Pre-centrifugation phase
Centrifugation phase
Post-centrifugation phase
Serum or plasma must be stored at _______ if analysis is to be delayed more than 4 hours
4–6°C
Formula for the relative centrifugation force?
RCF = 1.118 × 10−5 × r × rpm^2
Use for quality control for centrifuge?
Tachometer or strobe light
Centrifuge should be cleaned _____ and calibrate ____
Every week
Every quarterly
