LAB1 - preanalytical variables Flashcards by CHARLENE SAN JOSE

components of
PRE-ANALYTICAL PHASE

Test ordering / requisition
Patient identification
Phlebotomy
Specimen transport
Specimen examination
Centrifugation
Time to testing and storage

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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

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any influences that may be cause false-positive/negative,
false-increase/decrease results

PRE-ANALYTICAL VARIABLES

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FACTORS LEADING TO PRE-ANALYTICAL VARIABILITY

Complex biochemical and cellular reactions measured in assays
Liability of several analytes
Dependence of reactions on certain substances

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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

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serum and plasma right after eating

Serum or Plasma may appear lipemic, cloudy or turbid appearance right after eating

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Serum or Plasma may appear lipemic, cloudy or turbid appearance due to the presence of ____

fatty compound

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what chemical test iare mostly affected of diet after eating

glucose and triglyceride

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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

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a phenomenon called ____ is a turbidity of the serum or plasma
and potentially interfering with instrument readings
(happens after eating)

Hyperchylomicronemia

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(compounds/ analytes which affected immediately after eating

Elevate ↑

plasma potassium,
alkaline phosphatase,
5 HIAA (hydroxyindoleacetic acid)

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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

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what vitamin deficiency will long vegetarian will have due to low lipid intake?

Vitamin b12

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➢ A high meat or other protein-rich diet will increase what analytes/compounds

✓ Serum urea
✓ Ammonia
✓ Urate levels

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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)

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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)

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what are the ketone bodies that will increase if you eat a lot of protein but low carbs

acetone
acetoacetic acid
3 betahydrobutyric acid

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High unsaturated-to-saturated fatty acid will cause a decrease it what analyte

decreased
serum cholesterol

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Purines will primarily increase what NPN(non protein nitrogen)

urea (urate value )

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Bananas, pineapples, tomatoes, and avocados will elevate what analyte or compound?

urine excretion of 5 HIAA (5 hydroxybutyric acid)

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Obesity will be observed with what analyte?

increased serum LD activity, cortisol
production, and glucose.

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describe the insulin concentration of an obese as well as their glucose tolerance

Plasma insulin concentration is increased and the glucose tolerance is impaired

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describe the testosterone of an obese man

decreased

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describe the glucose level of a person after alcohol consumption

transiently elevated

nababalik pa rin sa normal yes yes yow

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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