Clinical Biochemistry

Question 1

fluids

core biochem component

Answer 1

mostly water
-2/3 ICF
-1/3 ECF > plasma + interstitial fluid

de/over hydration

signs not well seen at first bc spread across ICF and ECF

Question 2

ECF electrolytes

Answer 2

sodium, chloride, bicarbonate

Question 3

ICF electrolytes

Answer 3

potassium, phosphate, proteins

Question 4

sodium

clinical correlate

Answer 4

principle ECF cation so maintains blood vol and pressure by osmosis

hyponatremia- low serum Na, loss of sodium or water retention, rare, edema
vs
hypernatremia- high serum Na, water loss or sodium gain, elderly pts, kids w/ diarrhea

Question 5

glucose

serum metabolites

Answer 5

inform about diabetes
hypoglycemia- below 4 mmol/L, sweeting, tremors, coma, death,
-from insuff carbs or insulin OD in diabetics

hyperglycemia- above 7 mmol/L, from insuff insulin

Question 6

creatinine

metabolites

Answer 6

both excreted by kidneys w/ urine
inform about kidney function

inc serum creatinine = prob w/ kidneys (glomerular filtration) bc daily production is constant
creatinine clearance via urinary excretion also indicate glomerular probs if low

Question 7

BUN

blood urea nitrogen

Answer 7

balance b/t amino acid degredation and urea production
less specific indicators of kidney function

if inc levels w/ normal protein intake = impaired renal excretion

if dec levels = maybe severe liver disease or high anabolic state

Question 8

uric acid

Answer 8

waste product of purine degradation (nitrogen)

high levels = impaired renal excretion, inc chance of gout (uric acid crystalllizes = inflammation)

Question 9

albumin functions

serum proteins

Answer 9

produced by liver to bind/transport steroid hormones, fatty acids, unconjugated bili

binds calcium

maintains oncotic pressure

Question 10

albumin levels

serum proteisn

Answer 10

low (hypoalbuminemia) = edema bc water drawn out of serum into tissues
-from liver disease, malnutrition, severe starvation

Question 11

globulins

serum proteins

Answer 11

mixture of proteins from liver or immune system (immunoglobins)
transport ions, hormones, lipids

Question 12

CRP (C Reactive Protein)

Answer 12

by liver into blood for injury or inflammation

levels rise first 6 hrs after injury, peak at 48 hr so if don’t go down = impair healing process

Question 13

markers for myocardial infarctin

serum enzymes- heart

Answer 13

-myoglobin: quickly released into blood after MI
-creatine kinase: cardiac isozyme (CKMB) detectable early after MI but disappears quickly (3 days)
-AST: aspartate, released later than CKMB but detect for more than 8 days
-troponins: TnC, most sensitive marker, very early after MI, if not present 12 hr after onset chest pain then not MI
-LDH: late marker of MI several days after

Question 14

AP (alkaline phosphatase)

serum enzymes

Answer 14

removes phosphate from proteins at alkaine pH (10)

isoforms: biliary tract, bone remodelling, liver SO inc serum levels = bone or liver disease, or obstruction of biliary tract

Question 15

AST and ALT

Answer 15

high AST/low ALT = heart or muscle damage

high AST/high ALT = liver damage

Question 16

urine analysis

Answer 16

1. glucose = hyperglycemia
2. bilirubin = biliary obstruction
3. ketones = active fatty acid breakdown from diabetes, alcoholism, prolonged starvation
4. proteins = renal disease
5. blood = malignancy, UTI, contamination, menstruation
6. leucocytes = acute inflammation, UTI

Question 17

LFT (liver function test)

Answer 17

1. bilirubin = block bile flow, high conjugated
2. alkaline phosphatase = blockage bile duct, liver, bone disease
3. ALT/AST = hepatocellular damage
4. albumin = hypo strong indicator for liver disease or severe starvation

Question 18

Kidney function test

Answer 18

1. serum BUN: inc in renal dysfunction
2. serum creatinine= renal dysfunction
3. creatine clearance = less creatine w/ dysfunction
4. proteinuria/albumin = in urine indicate renal disease or diabetic nephropathy