Pre-analytic Variables Flashcards
begins when a test is ordered and ends when testing begins
preanalytical or pre-examination phase
Factors during this testing phase when not properly adressed can lead to errors that can compromise specimen quality, jeopardize/harm the health and safety of the patient, and ultimately increase the cost of medical care
Preanalytical phase or pre-examination phase
What are the three purposes of performing tests? (ConDiMon)
- Confirm health or to screen for
- Diagnose
- Monitor disease
True or False. Test results need not to be compared with results expected of healthy individuals.
False. Tests results need to be compared with results from healthy individuals.
A range of values with high and low limits which are results used for comparison.
Reference range or reference interval
What happens when a specimen has been compromised and the results are not valid?
The physician could make a decision based upon incorrect information and thus jeopardize the patient’s care.
Refers to the resting metabolic state of the body early in the morning after fasting for approx. 12 hourrs.
Basal State
Ideal for establishing reference ranges on inpatients because the effects of diet, exercise, and other controllable factors on test results are minimied or eliminated.
Basal-state specimen
What variables influence basal state? (AADeDiDiu/CirDruEFGIJPPreSmoStreTemHum)
age, altitude, dehydration, diet, diurnal/circadian variations, drug therapy exercise, fever, gender, intramuscular injection, jaundice, position, pregnancy, smoking, stress, temperature and humidity
True or False. Outpatient specimens are not basal-state specimens and may have slightly different reference ranges (normal values).
True
True or False. RBC and WBC values are normally lower in newborns than in adults.
False. RBC and WBC are normally higher in newborns than in adults.
True or False. Kidney function decrease with age.
True
True or False.
S1: Decreased oxygen levels at higher altitudes cause the body to produce less RBCs.
S2: The higher the altitude, the greater the increase of RBCs
Only Statement 2 is correct. The higher the altitude, the more RBCs are produced.
A condition in which blood components that cannot easily leave the bloodstream become concentrated in the smaller plasma volume.
hemoconcentration
How long are patients asked to fast?
Approx. 8 to 12 hours
Fasting beyond 12 hours can cause serious health problems. What are examples of such?
- Electrolyte imbalance
2. Heart rhythm disturbances
Analytes that may be elevated in patients on high-protein diets (AUU)
Ammonia, urea, uric acid levels
Analytes that increase with the consumption of caffeine
Cortisol and adrenocorticotropic hormone (ACTH) levels
An analyte that increase with the ingestion of carbs or sugar-laden substances and insulin levels
Glucose (blood sugar) levels
An analyte that decrease and electrolyte balance can be altered by drinking excessive amounts of water and other fluids.
Hgb levels
An analyte that increase with ingestion of food such as butter, cheese, cream, and some enteral (tube feeding) preparations
lipid levels
Abnormally increased blood lipid content
Lipemia
The cloudy or turbid appearance of the specimen
Lipemic
How long can lipemia be present?
up to 12 hours
A condition characterized by increased bilirubin (a product of the breakdown of RBCs) in the blood, leading to deposits of yellow bile pigment in the skin, mucous membrane, and sclerae (whites of the eyes), giving the patient a yellow appearance
Jaundice/Icterus
Serum, plasma, or urine specimens that have an abnormal deep yellow to yellow-brown color due to high bilirubin levels
icteric