Block 1 Flashcards
Two types of pathology
Anatomic; Clinical
Three subjects needed to interpret labs
Population prevalence; Disease incidence; Test characteristics
5 reasons to order a lab test
Order; Routine check up; Pre-op; Monitoring; Diagnostics
Usual values found in a population
Reference Range
Optimal health or minimal risk of related complications and disease
Optimal Range
Specific to lab based on equipment and methods
Reference Range
Range that varies with age, sex, race, diet, drugs, stress and population
Reference Range
Assay imprecision or Test error variability
Analytical Variability
Natural biological fluctuation or lifestyle variation
Intra-individual variability
General Chemistry Test
Comprehensive Metabolic Panel (CMP)
CMP gives info on (7):
Na; Cl; BUN; K; HCO3; Cr; Glu
5 main electrolytes
Na; Cl; Mg; Ca; K
Amount of tests annually
6.8 billion
Increases by how much %
7% annually
5 major liver functions
- Synthesis and secretion of proteins
- Storage of energy (glycogen)
- Metabolizes drugs and toxins
- Transformation and clearance
- Aids digestion through Biliary System
5 Liver Tests
Globulin; AST; ALT; Bilirubin; Albumin
Globulin contains
100s of serum proteins, including carrier enzymes, complement immunoglobulins
Increase or decrease in Globulin should be evaluated by
Serum Electrophoresis
Asparate Aminotransferase (AST) found in
Liver tissues
AST detects
Liver damage
Alanine aminotransferase (ALT) founf
in cytosol of liver
ALT detects
Liver damage
Which is more specific, ALT or AST
ALT
Increased levels of ALT or AST can be caused by
Viral Hep, Fatty Liver, Toxins due to medications, Strenuous exercise
Bilirubin formed from
Old Blood Cells
Bilirubin is conjugated where
In the liver
Bilirubin is conjugated in the liver with
glucuronic acid
The role of glucuronic acid with bilirubin is
to make is soluble
In the intestine glucuronic acid is removed by bacteria forming
Urobilinogen
A portion of the urobilinogen participates in what cycle?
enterohepatic
Indirect testing for bilirubin indicates
pre-hepatic
Direct testing for bilirubin indicates
post-hepatic
Increase in indirect bilirubin can be caused by
- increased production
- impaired conjugation function
- impaired hepatic intake of bilirubin
Diseases known to cause increase in indirect bilirubin
- Hemolysis
- Kernicterus
- Grigler-Najjar
- Gilberts
Increase in direct bilirubin can be caused by
- elevated conjugated bilirubin levels
- hepatobiliary obstructon
- reduced secretion of conjugated bilirubin into bile or into intestines
Diseases that can cause increase in direct bilirubin
Hepatitis; Dubin- Johnson syndrome
Albumin is synthesized
in the liver
Albumin with globulins make up
total protein in serum
synthesized in what amount
150-250 mg/kg/ day
a 70kg man makes how much albumin a day
10-18g
Main agent of intravascular osmotic pressure
Albumin
Albumin transports
bilirubin, hormones, metats, vitamins and drugs
Increased level of albumin caused by
acute dehydration
Decreased levels of albumin caused by
depressed synthesis or increased losses
Diseases that can cause a DECREASE in synthesis of albumin
End stage liver disease, intestinal malabsorption syndromes, protein malnutrition
Protein malnutrition and decreased synthesis of albumin can lead to what syndrome
Kwashiorkor “rice diet”
Disease that can cause a LOSS in albumin
Nephrotic syndrome, severe burns
Extra storage for albumin is found in
skin
Kidney Functions
waste, erythropoein, renin, vit D synthesis
Kidney processes how many liters of blood a day
200L
Erythropoetin stimulates
red blood cell production in bone marrow
Renin is used in
Regulation of blood pressure
Kidney Tests
Urinalysis, Creatine, Blood Urea Nitrate (BUN)
BUN tests for
breakdown of proteins
Creatine tests for
breakdown of creatin in muscles
Rate of elimination of creatine is proportional to
glumural filtration
Physical, chemical and microscopic exam of urine
Urinalysis
Heart tests
Lipid panel, Brain (B-type) Natriuretic protein, troponins
Lipid panel tests for
cholesterol, triglycerides, HDL, Choles/HDL ratio, LDL calculated
Lipid panel shows risk of
heart disease
Urinalysis catergories
Urobilinogen, glucose, ketone, bilirubin, protein, nitrite, leukocyte, blood, ph, SG stick, sediment
Increase in nitrite and leukocytes in urinalysis can indicate
urinary infection
BNP secreted in heart due to
excessive stretching of heart muscle
BNP differentiates between
congested heart failure and other causes of dysphea
Troponin is released when
heart muscle is damaged
Most specific when looking for heart infraction
Troponin I
Lab test for brain
cerebrospinal fluid analysis
Lab test for lungs
Ph, Co2 levels, O2 levels and lung size
Thyroid function lab test
TSH levels
Parathyroid hormone (PTH) levels can indicate
issues with bone marrow or Ca2
Most common test inappropriately ordered
estrogen
Endocrine tests
TSH, FSH, LH, PTH, Estrogen, Testerone
Osler’s rule
all abnormalities into one dx