LAB1 - preanalytical variables Flashcards
components of
PRE-ANALYTICAL PHASE
- Test ordering / requisition
- Patient identification
- Phlebotomy
- Specimen transport
- Specimen examination
- Centrifugation
- Time to testing and storage
Any influence before testing of the specimen that causes the
test to fail to reflect the patient’s in vivo body functions
PRE-ANALYTICAL VARIABLES
any influences that may be cause false-positive/negative,
false-increase/decrease results
PRE-ANALYTICAL VARIABLES
FACTORS LEADING TO PRE-ANALYTICAL VARIABILITY
- Complex biochemical and cellular reactions measured in assays
- Liability of several analytes
- Dependence of reactions on certain substances
examples of pre-analytical variables
diet (food and beverages)
fasting
posture/position
tourniquet application
exercise
stress/ anxiety
smoking
altitude
age and gender
pregnancy
diurnal variation
medication
serum and plasma right after eating
Serum or Plasma may appear lipemic, cloudy or turbid appearance right after eating
Serum or Plasma may appear lipemic, cloudy or turbid appearance due to the presence of ____
fatty compound
what chemical test iare mostly affected of diet after eating
glucose and triglyceride
2 reasons why lipemic sample affects any test result
- It will affect the optical measurement or absorbance reading
(spectrophotometry analysis) - Cause of lipemia (chylomicrons) itself interfere the test
a phenomenon called ____ is a turbidity of the serum or plasma
and potentially interfering with instrument readings
(happens after eating)
Hyperchylomicronemia
(compounds/ analytes which affected immediately after eating
Elevate ↑
plasma potassium,
alkaline phosphatase,
5 HIAA (hydroxyindoleacetic acid)
what will decrease to lipid values of a Long-time vegetarian
✓ Low-density lipoproteins (LDLs)
✓ Very-low-density lipoproteins (VLDLs)
✓ Total lipids
✓ Phospholipids
✓ Cholesterol
✓ Triglycerides
what vitamin deficiency will long vegetarian will have due to low lipid intake?
Vitamin b12
➢ A high meat or other protein-rich diet will increase what analytes/compounds
✓ Serum urea
✓ Ammonia
✓ Urate levels
why A high meat or other protein-rich diet will increase urea, ammonia, and urate levels?
because these compound are end product of
metabolism of PROTEIN
Protein - made up of AMINO ACID (once
amino acid undergo deamination, it will become
AMONIA, as amonia binds itself with carbon
dioxide, it will form UREA)
analytes or compounds that will increase in High protein, low carbohydrate diets
greatly increase ketones in the urine and increase the serum blood urea
nitrogen (BUN) (Atkins Diet)
what are the ketone bodies that will increase if you eat a lot of protein but low carbs
acetone
acetoacetic acid
3 betahydrobutyric acid
High unsaturated-to-saturated fatty acid will cause a decrease it what analyte
decreased
serum cholesterol
Purines will primarily increase what NPN(non protein nitrogen)
urea (urate value )
Bananas, pineapples, tomatoes, and avocados will elevate what analyte or compound?
urine excretion of 5 HIAA (5 hydroxybutyric acid)
Obesity will be observed with what analyte?
increased serum LD activity, cortisol
production, and glucose.
describe the insulin concentration of an obese as well as their glucose tolerance
Plasma insulin concentration is increased and the glucose tolerance is impaired
describe the testosterone of an obese man
decreased
describe the glucose level of a person after alcohol consumption
transiently elevated
nababalik pa rin sa normal yes yes yow
Chronic alcohol consumption - tests associated with the liver and increases which type of lipid
triglycerides
____ use as marker of chronic
alcoholism
Gamma glutamyl transferase (GCT)
fill in the blanks according to the discussed topic
Caffeine - affect ____ levels; elevate plasma _____ and cause _____ release from the
adrenal medulla and brain tissue
hormone; free fatty acids; catecholamine
it refers to the balance of the solute and solvent in the body
osmolality
what are affected if you drink to much liquid as per the discussed topic?
hgb and electrolyte balance
samples collected in basal state
glucose, cholesterol, triglyceride
and electrolytes
what does basal state means
Basal state- resting metabolic state
Specimen that requires fasting
Glucose: FBS, GTT, TAG,
Lipid profile: lipid and lipoprotein tests,
Analyte: gastrin and insulin
desired fasting hours of glucose, lipids and lipoproteins
8-14 hours
48 hours of fasting may ____ serum bilirubin
increase, decrease
increase
72 hours of fasting may result to ___ of plasma triglyceride while glucose _____in health women to 45
mg/dL (2.5 mmol/L),
increase; decreases
upon fasting,
Men show an increase in plasma triglycerides, glycerol, and free fatty acids, with no significant change in ___
plasma
cholesterol.
National Institutes of Health recommends that patients be lying or sitting for how many minutes prior to blood collection for lipid profiles to minimize the effects caused by posture
5 minutes
POSTURE :
variation in blood constituent increase about ___ within 10mins.
4-15%
for patients with cirrhosis and congested heart failure are more concentrated in what areas
interstitial spaces
effects of Changing from supine to
sitting or standing on the following:
albumin, enzymes and calcium
increased
effects of Changing from sitting to
supine to the following:
proteins, lipids,
BUN, iron and calcium
Increased
Changing from standing to
supine
↓ Decreased levels of cholesterol,
triglycerides and lipoproteins
effect of 30 minutes of standing in potassium
Significant elevation of potassium
Prolonged bedrest ↓ Decreased plasma albumin
effect of Prolonged bedrest to plasma albumin
Decreased plasma albumin
effect of Standing to plasma renin
Plasma renin is higher than supine
position
describe what will happen to serum aldosterone and catecholamine upon standing within 1 hr
could double up within
an hour
patient that have prolong standing, they
should be lying down, in a specific sitting
position for at least __before
collecting samples)
30mins
It is recommended that tourniquet application should not be
more than ___
one minute
Prolonged tourniquet application results to
___.
hemoconcentration and anaerobiosis
The pressure from
the tourniquet causes biological analytes to ___
leak from the tissue cells into the blood
there will be an increased level of
____ if the tourniquet takes more than 1 mn
○ Potassium (1 mmol/L)
○ Proteins (albumin)
○ Enzymes
○ Lactate
○ Cholesterol
○ Ammonia
the most affected analyte in prolonged tourniquet application
potassium
Decreased levels of ___ are observed in prolonged tourniquet
○ Venous pO2
○ pH (acidic)
if the oxygenation in blood is decrease, what will happen to the blood’s pH level
decrease, lower oxygen will turn the blood to become acidic
the effect of the exercise is depending on the ___ patient
physical fitness and muscle mass of the patient
Moderate or strenuous exercise will increase which compound/analyte
○ blood levels of creatinine
○ fatty acids
○ lactic acid
○ aspartate aminotransferase (AST)
○ creatine kinase (CK)
○ lactic dehydrogenase (LD)
○ Aldolase
○ Hormones
○ Bilirubin
○ uric acid
○ high-density lipoprotein (HDL)
○ white blood cell (WBC) coun
hormones released during Moderate or strenuous exercise
- antidiuretic hormone
- aldosterone
- catecholamines
- renin
- growth hormone
- angiotensin
- cortisol
compounds that are expected to decrease in moderate and strenuous exercise
○ Arterial pH
○ PCO2.
a technique in venipuncture that must be avoided if the test is potassium and phosphate
fist clenching
Affected analyte that will caused an Increased upon performing strenuous activity
▪ Prolactin
▪ Testosterone
▪ LH
▪ Protein (urine)
▪ Potassium,
Lactate
& Phosphate
(fist clenching)
Affected analyte that will caused an transient Increased upon performing strenuous activity
▪ Lactate
▪ Pyruvate
▪ Fatty Acid
▪ Creatinine
▪ Ammonia
Affected analyte that will caused an long term Increased upon performing strenuous activity
▪ CPK
▪ AST
▪ LD
▪ Aldolase
Affected analyte that will caused an decrease upon performing strenuous activity
▪ FSH
▪ LH
(In long distance
athletes)
STRESS / ANXIETY has an increased in what hormones
Increased levels of adrenal hormones (cortisol and
catecholamines),
STRESS / ANXIETY has an increased in what cell count
wbc count
what are common in long term increase in terms of analytes affected by exercise
Enzyme
found/ release
by skeletal
muscle
the lab test affected and will decrease specially for patients who are actively performing and exercise is part of their daily routine
FSH and LH
STRESS / ANXIETY wll decreased the result levels of what test
serum iron, and markedly affect arterial blood
gas (ABG) result
what cell count collected from a violently crying newborn may
be markedly elevated
WBC counts
Severe anxiety → hyperventilation (excessive release of CO2
which can cause ___)
alkalosis
Total cholesterol has been reported to ____ with mild
stress, and HDL cholesterol to decrease by as much as
____
increase; 15%.
Immediate effects of nicotine
→ increases in:
○ Plasma catecholamines
cellular element effect of smoking
decreased numbers of eosinophils, while
neutrophils, monocytes, and plasma fatty free acids increase
what will happen to
○ Glucose
○ Blood urea nitrogen (BUN)
○ Cholesterol
○ Triglycerides
upon smking
increased
how many percent do Glucose and BUN can increase upon smoking?
by 10%
how many percent can triglyceride increase upon smoking
triglycerides
by 20%
in hema and imse , chronic smoking can increase the values of
Chronic smoking increases
hemoglobin,
red blood cell (RBC) counts,
the mean corpuscular volume (MCV) and
immunoglobulin (Ig) E.
what are the immunoglobulins that will be affected during smoking
Immunoglobulins (MAG-yosi)IgA, IgG, and IgM are decreased,
lowering the effectiveness of the immune system
Tobacco smokers have high blood ______
levels
carboxyhemoglobin
pregnancy
Caused by the physiological changes in the body including
increases in ___
plasma volume
Increased plasma volume may cause a dilutional effect
and cause lower ___
RBC counts, protein, alkaline
phosphatase, estradiol, free fatty acids, and iron values.
____ is the normal fluctuation in blood levels at
different times of the day based on a 24-hour cycle of
eating and sleeping
Diurnal rhythm
Levels are highest in the morning
○ Cortisolaldosterone
○ Renin
○ Luteinizing hormone
○ Follicle-stimulating hormone
○ Estradiol
○ Thyroid-stimulating hormone (TSH)
○ Testosterone
○ Bilirubin
○ Hemoglobin
○ Insulin
○ Potassium
○ RBC count
○ Serum iron
Levels are lower in the morning
○ Eosinophil counts
○ Creatinine
○ Glucose
○ Triglyceride
○ Phosphate
Medications that are toxic to the liver (Hepatotoxins) can
cause an increase in ___
blood liver enzymes and abnormal
coagulation tests
IV administration of dyes used in diagnostic procedures,
including radiographic contrast media for kidney disorders
and fluorescein used to evaluate cardiac blood vessels,
can interfere with testing procedures
true or false
truthfully imnida
_____ may be noted in patients taking medications that impair renal
function
Elevated BUN levels or imbalanced electrolytes
Patients taking corticosteroids, estrogens, or diuretics can
develop ____ and would have elevated serum
amylase and lipase levels
pancreatitis
test affected by diurnal variation, posture, and stress
cortisol
peaks:
lowest:
50% lower at:
_____ with stress
cortisol
peaks: 4-6 am
lowest: 8 pm - 12 am
50% lower at: 8pm than 8 am
increased with stress
test affected by diurnal variation, posture, and stress
adrenocorticotropic hormone
lower at _____
____ with stress
lower at night
increased with stress
test affected by diurnal variation, posture, and stress
plasma renin activity
lower at _____
_____ standing than supine
lower at night
higher standing than supine
test affected by diurnal variation, posture, and stress
aldosterone
lower at _____
lower at night
test affected by diurnal variation, posture, and stress
insulin
lower at _____
lower at night
test affected by diurnal variation, posture, and stress
growth hormone
_____ in afternoon and evening
higher in afternoon and evening
test affected by diurnal variation, posture, and stress
acid phosphatase
_____ in afternoon and evening
higher in afternoon and evening
test affected by diurnal variation, posture, and stress
thyroxine
___ with exercise
increases with exercise
test affected by diurnal variation, posture, and stress
prolactin
_____ with stress,
_____ levels at 4 and 8 am and at 8 and 10 on
higher
test affected by diurnal variation, posture, and stress
iron
peaks at _____
______ during the day
peaks early to late morning
decreased up to 30% during the day
test affected by diurnal variation, posture, and stress
calcium
_______ % decrease supine
4% decrease supine
acetaminophen and certain antibiotic
what is the affected test/systems?
elevated liver enzymes and bilirubin
cholesterol-lowering drugs
what is the affected test/systems?
prolonged PT and APTT
certain antibiotics
what is the affected test/systems?
elevated BUN, creatinine, and electrolyte imbalance
what is the affected test/systems?
corticosteroids and estrogen diuretics
elevated amylase and lipase
what is the affected test/systems?
diuretics
increased calcium, glucose, and uric acid and decreased sodium and potassium
what is the affected test/systems?
chemotherapy
decreased rbcs, wbcs, and platelets
what is the affected test/systems?
aspirin, salicylates, and herbal
prolonged PT and bleeding time
what is the affected test/systems?
radiographic contrast media
routine analysis
what is the affected test/systems?
fluorescein dye
increased creatinine, cortisol, and digoxin
what is the affected test/systems?
oral contraceptives
decreased apoproteins, transcortin, cholesterol, HDL, triglycerides, LH, FSH, ferritin and iron
