Lab Values Flashcards
List 3 different types of diagnostic tests
- Molecular test
- Antigen test
- Antibody test
What are molecular tests?
a type of diagnositc test that detect the genetic material of a virus
ex: RT-PCR test
what is an antigen test?
a diagnostic test that detects specific proteins found on the surface of the virus
also known as rapid diagnostic test
what is an antibody test?
also called serological test
a diagnostic test for antibodies that are made by the immune cells (lymphocytes) in response to a threat, such as a specific virus
T/F: reference values are not the same as normal values?
FALSE
interchangeable terms
*always compare pt values to the reference values determined at that lab
how are reference values established?
- test large numebrs of healthy individuals
- blood donors, med students, med techs, etc.
- results are evaluated statistically
- values with 2 SD of mean are typically considered normal
T/F: screening tests and diagnostic tests are the same thing
FALSE
screening tests are used to potentially ID individuals at risk
diagnostic tests confirm if those at risk individuals have the disease
avoid PT if fasting blood glucose levels are ______
>250 mg/dl
and if ketosis is present
use caution if glucose >300 mg/dl
what electrolyte is a critical determinant of blood volume?
Sodium
what is normal range for sodium levels in an adult?
135-145 mEq/L
elevated sodium levels can suggest _________
water loss or dehydration
depressed sodium concentrations can suggest ________
water retention
what is hypernatremia?
elevated sodium concentation
List some causes of hypernatremia
- increased fluid loss (sweating)
- adrenal gland dysfunction
- increased aldosterone secretion favors Na retention
- limited water intake (geriatic pops)
- medications
- diuretics, ACE inhibitors = favor water loss
- ARBs = favor water retention
- Excessive dietary intake
what is hyponatremia?
decreased sodium concentration
List some causes of hyponatremia
- excessive water intake (hypervolemia)
- CHF, kidney failure, liver disease
- severe vomiting and diarrhea
- inadequate Na intake
- Diuretics = bulk flow of water
- adrenal gland dysfunction (addison’s disease)
what electrolyte is important for normal function of excitable cells?
Potassium (K)
what is the normal range for K+?
3.5 - 5.5 mEq/L
how can potassium abnormalities influence physiology?
- abnormalities can change the resting membrane potential and hence the excitability of excitable cells
- change in potassium levels provide insight into renal and adrenal function
what is hyperkalemia and how can it influence physiology?
it is high levels of K+
brings membrane potential closer to the threshold needed for the generation of an AP
results in arrhythmias
what is hypokalemia and how can it influence physiology?
low levels of K+
leads to hyperpolarization
makes the membrane more (-) and more difficult to stimualte
list some conditions that can result from hyperkalemia
- abnormal HR
- respiratory arrest
- neurologic consequences
list some conditions that can result from hypokalemia
- palpations
- fatigue, leg cramps, muscle weakness
- flaccid paralysis
- N&V
- constipation
List some causes of hyperkalemia
- kidney failure
- hypoaldosteronism/disease of adrenal gland
- dietary intake
- NSAIDs, ARBs, diuretics
List some causes of hypokalemia
- diarrhea
- N&V
- Diuretics
- Kidney dialysis
- low dietary intake
the s/s of hyperkalemia are MURDER, list them
- Muscle cramps
- Urine abormalities
- Respiratory distress
- Decreased cardiac contractility
- EKG changes
- Reflexes
What is the reference range for Ca2+?
- 1 - 2.6 mmol/L
- 8 - 10 mg/dL
- 3 - 5.2 mEq/L
how would you expect Ca levels to look in an individual with hyperparathyroidism?
increased
increased PTH = increased osteoclast activity releasing Ca from bones and into circulation
What causes hypocalcemia and what are it’s short and long term effects?
can result from renal disease and certain meds (diuretics)
short term:
- numbness and tingling
- muscle cramps and tetany
- lethargy
- convulsions (neuromuscular instability)
- negative chronotropic effect and ionic effect
long term:
- osteopenia
- OA
what causes hypercalcemia and what are it’s effects?
associated with hyperparathyroidism caused by excessive release of PTH
Effects:
- kindey stones
- bone pain
- abdominal pain
- tachycardia
Stone, bones, and groans
what are the normal fasting glucose levels in adults?
70 - 100 mg/dL
what are the normal fasting glucose levels in elderly adults (<60)
80 - 110 mg/dl
what are the normal fasting glucose levels in children and neonates?
children = 60 - 100 mg/dl
neonates = 40 - 80 mg/dl
what is impaired glucose tolerance (IGT)?
a glucose value between 140-200 mg/dl 2 hours after drinking a glucose solution
associated with glucose resistance
increased risk for developing diabetes
How is a glucose tolerance test performed?
- pt is fasted
- blood sampled
- pt consumes a high CHO drink
- blood is sampled 1-2 hrs later
- do serum glucose levels increase and then return to normal levels in a timely manner?
what is hemoglobin A1c?
a test for long-term glycemic control
what % are we looking out for when looking at Hemoglobin A1c?
7%
if it is above it means poor glucose control
6-7% is fair control
lower the better
what blood glucose level is associated with hypoglycemia? what about hyperglycemia?
hypo = <70 mg/dl
hyper = >200 mg/dl
a subject with a consistent blood glucose range between ______ and ______ is considered hyperglycemic
100 and 126 mg/dl
above 126 is considered to reflect diabetes
what are the symptoms of chronic hyperglycemia?
- polyphagia (frequent hunger)
- polydipsia (frequent thirst)
- Polyuria
- Blurred vision
- fatigue
- weight loss
- poor wound healing
- cardiac dysrhythmias
what is ketoacidosis?
develops when the use of glucose is severely limited resulting in increased break down of fats resulting in high levels of ketone bodies/ketosis
ketones lower blood pH
What is the normal value for Creatinine in adults?
- 6 - 1.2 mg/dl (males)
- 5 - 1.1 mg/dl (females)
how are normal creatinine levels maintained?
glomerular filtration at the kidneys
what do elevated serum creatinine values mean?
suggest a decline in kidney’s capacity for excreting waste
T/F: creatinine clearance rate decline with age
TRUE
What are normal levels for blood urea nitrogen (BUN)?
6 - 20 mg/dl
what is BUN a measure of?
measure the amount of urea nitrogen
this is a waste product of liver catabolism of amino acids present in serum
what causes BUN levels to rise?
decreased renal function and decreased renal clearance
Elevated BUN is associated with what?
- heart failure
- gastrointestinal bleeding
- hypovolemia
- kidney disease/failure
- shock
- urinary tract obstruction
what is the normal range for bilirubin?
0.1 - 1.0 mg/dl
what is bilrubin and what is it used to asses?
reddish-yellow substance formed when hemoglobin is broken down and then processed by the liver and excreted in bile
used to asses liver function
how would liver disease/damage impact bilirubin?
it would reduce the amount of bilirubin that is modified in the liver and removed from the blood = bilirubin accumulates in the blood = jaundice
List some causes of elevated bilirubin
- Increased RBC desctruction = increased bilirubin which can not be effectively dealt with
- sickle cell anemia
- hemolytic anemia
- transfusion reaction
- anatomic obstruction
- limits movement of bilirubin to the small intestine
- biliary strictures
- gall stones
what is the normal reference value for albumin?
3.5 - 5.5 g/dl
what is albumin?
a protein synthesized in the liver
transports many small charged molecules in the blood
it makes up 2/3 of blood proteins and is important in maintaining oncotic pressure
what can cause lower-than normal levels of albumin?
liver disease (can’t synthesize it)
malnutrition (lack raw materials)
List conditions that are assocaited with low serum levels of albumin
ascites (abdominal edema)
burns = high vascular permeability (loss from blood)
glomerulonephritis (kidney disease)
malnutrition
malabsorption syndroms (crohn disesae, celiac disease, or Whipple disease)
what can glomerulonephritis lead to?
albuminuria = too much albumin in urine
shouldnt be there normally as it is normally too big to enter the tubules from the blood
List other markers of Liver function
Liver panel which will include:
- AST (aspartate aminotrasferase)
- ALT (alanine aminotrasferase)
- LDH (lactate dehydrogenase)
- GGT (gamma-glutamyl transpeptidase)
*these tell us about the activity of these enzymes not their concentrations
Increased RBC can be a result/indicative of what?
- polycythemia vera
- dehydration
- severe dirrhea
- poisoning
- pulmonary fibrosis
- high altitude
- chronic heart disease
decreased RBC can be a result of/indicative of what?
- anemia
- blood loss
- Hodgkin’s disease
- multiple myeloma
- leukemia
- SLE
- rheumatic fever
- endocarditis
what are the reference values for RBC for men/women?
male = 4.5 - 5.3 x 106/mm3
female = 4.1 - 5.1 x 106/mm3
what are the reference values for hemoglobin?
male = 13-18 g/dl
female = 12-16 g/dl
what is the reference value for hematocrit?
male = 37-49%
female = 36-46%
T/F: A WBC count is only for neutrophils?
False
while it generally represents the number of neutrophils it is for all WBCs
what value represents the body’s ability to fight infection?
Absolute neutrophil count (ANC)
an estimation of the number of neutrophils in the blood
list the tests of coagulation
Prothrombin time (PT) activated partial thromboplastin time (aPPT)
what are test of coagulation for?
used to determine coagulability either diagnostically or to monitor anticoagulant therapy of heparin or warfarin
run pre-surgery and when anti-coagulant therapy is given
PT = 12-15 sec
aPTT = 30-40 sec
what is the international normalized ration (INR)?
developed to reduce variability in results between labs
it is a standarized method of determinig clotting time and hence bleeding risk
INR = ______/_______
prothrombin test/prothrombin control
ratio of the pt’s to a normal control’s prothrombin time
INR can be prolonged (larger) in:
- presence of anticoagulants
- liver dysfunction
- Vitamin K deficiency
- coagulation factors deficiency
what is the specific gravity of urine?
a ratio of the density of a substance (urine)/ density of a reference substance (water)
reflects the concentration of excreted molecules in the urine
what is the normal reference value for the specific gravity of urine in adults?
1.005 - 1.030
what is the normal pH of urine (during a urinalysis)?
4.6 - 8.0
a higher urine pH is indicative of what?
can be caused by severe vomiting
a kidney disease
some urinary tract infections
asthma
what may cause a low urine pH?
severe lung disease (emphysema)
uncontrolled diabetes
aspirin overdose
severe diarrhea
dehydration
starvation
alcohol or drinking antifreeze
