Serum Component
Sodium
Function
Maintain osmotic
pressure, acid-base
balance, nerve
impulses
Indication
Evaluate and monitor
fluid and electrolyte
balance and therapy
Interferences
Trauma, surgery,
shock.
Hypoemic Effects
Potassium
Nerve conduction,
muscle function, acidbase balance, osmotic
pressure, cardiac
muscle function
Cardiac function, any
type of serious illness,
patients taking
diuretics or heart
medications
Opening and closing of
the hand with a
tourniquet, hemolysis
of blood during
venipuncture,
laboratory processing.
Decreased contractility of
muscle, weakness,
muscle cramping,
tingling, paralysis,
hyporeflexia, flattened T
and prominent U waves.
Causes: IVF
administration without K+
supplementation.
Irritability, nausea,
vomiting, intestinal
colic, diarrhea, peaked
T waves, widened QRS
complex, depressed ST.
Chloride
Maintains electrical
neutrality- major
extracellular anion.
Buffer substance. Little
information can be
obtained regarding
lungs from CO2 value
Acid-base balance and
hydration status.
Excessive infusions of
saline
Lethargy, deep
breathing
Detect CO poisoning.
None.
Balance between
measured cations and
anions
Evaluation of acid base
disorders. Formula:
(Na++K+) – (Cl-+HCO3-)
Shallow breathing,
hyperexcitability of NS,
hypotension
Diabetic ketoacidosis,
chronic diarrhea, renal
failure, starvation,
metabolic acidosis,
thiazide or loop
diuretics
Non-anion gap
metabolic acidosis=
CRUDE
CO2 and HCO3-
Anion Gap
Level reaches <125 mEq/L.
Weakness, confusion,
lethargy, coma. Caused by
hypervolemic
hyponaturemia (dilutionalexcess body water vs. low
total body Na), hypovolemic
hyponaturemia (Na and H2O
depletion), euvolemic
hyponaturemia (relative H2O
retention).
Hyperemic effects
Level reaches >150
mEq/L. Thirst, dry
mucous membranes,
hyperreflexia,
convulsions.
severe vomiting, COPD,
metabolic alkalosis,
aldosteronism
Positive anion gap (>18)
indicates that there is a
problem with:
MUDPILES
Blood Urea Nitrogen
(BUN)
Metabolic liver
function, excretory
function of the kidney
Rough measure of
renal function and GFR
Pre-renal situations and
dehydration, False highs:
allopurinol, AMGs,
cephalosporins,
furosemide,
indomethacin, aspirin,
propanolol.
Primary liver disease
and failure, nephritic
syndrome, celiac
disease, malnutrition,
overhydration
Inadequate secretion 2nd to
kidney disease, urinary tract
obstruction. Called
“azotemia”. Increases can
be caused by reductions in
renal perfusion, increased
waste production, or
congenital problems that
cause urine back flow.
Creatinine
Catabolic product of
creatine phosphate
used in skeletal muscle
concentration.
Specific to renal
dysfunction—removed
from the plasma by GF,
excreted w/o
reabsorption to tubules,
Drug interference with
increased levels—
AMGs, cephalosporins,
nephrotoxic drugs
Decreased muscle
mass—debilitation in
muscular dystrophy
and myasthenia gravis
Kidney infx and dz, UT
obstruction,
rhabdomyolysis (large
releases of myoglobin),
increased muscle mass
Calcium
Cell membrane
potential and
permeability,
neuromuscular fx,
myocardial
contraction, bound to
albumin
Malignancy, vitamin
deficiencies, endocrine
disorders, kidney fx,
bone disorders, GI fx
Increased levels- Ca+2
salts, Li, thiazide
diuretics, PTH, thyroid
hormone, vitamin D
Decreased levelsanticonvulsants, ASA,
calcitonin,
corticosteroids, heparin,
OCPs
Symptoms—muscle cramps,
twitching, AMS
(tetany/hyperexcitability),
dysrhythmias, decreased
contractility, Chvestek’s
sign, Trousseau’s sign.
Hypoparathyroid,
hypoalbuminemia, large
transfusions, Rickets,
osteomalacia,
hypomagnesemia, acute
pancreatitis
Most commonly
asymptomatic. MCC in
elderly and hospitalized pts
= malignancy. MCC in young
and out pts=
hyperparathyroidism. Other
causes: hyperthyroidism,
PTH producing tumor,
Paget’s dz, renal failure,
Addison’s dz, Vit D
intoxication
Inorganic phosphate
Metabolism of glucose
and lipids,
maintenance of acidbase balance, storage
and transfer of energy,
required for generation
of bony tissue
Aids in the
interpretation of
parathyroid and Ca+2
abnormalities, avoid
hemolysis during blood
collection, intracellular
ion. Evaluated in
relation to calcium
(inverse relationship)
Increased levels—
methicillin, steroids,
some diuretics, excess
vit D.
Decreased levels—
antacids, albuterol,
estrogens, insulin, oral
contraceptives
Malnutrition, chronic acid
indigestion,
hyperparathyroid,
hypercalcemia, alcoholism,
Rickets, tx of hyperglycemia,
hyperinsulinism, recent CHO
infx, alkalosis. General
relationship with Ca is
inverse.
Low P, hi Ca, hi PTH =
primary hyperparathyroid
Low P, low Ca, hi PTH =
secondary hyperparathyroid
Signs/symptoms—
muscle weakness,
AMS, seizures.
Hypoparathyroid,
laxatives, enemas with
Na+ increased dietary
intake, hemolysis,
rhabdomyolysis,
acidosis
Magnesium
Intracellular
electrolyte. Related to
Ca and K.
Cofactor in modifying
activity of enzymes,
neuromuscular fx,
clotting mechanisms,
cardiac fx.
Increased levels—
thyroid meds, antacids,
laxatives, Li, loop
diuretics
Decreased levels—
diuretics, insulin, some
antibx
Uric Acid
Synthesized in the
liver—end product of
protein metabolism.
Purines, nitrogenous
compds. Determined
by liver synthesis and
kidney fx
Found in highly
metabolic tissue,
intracellular enzyme.
Not specific to the
liver.
Kidney stones, gout,
recurrent urinary
calculus
Increased levels—
EtOH, ascorbic acid,
low dose ASA, caffeine,
epinephrine.
Decreased levels—
allopurinol, high dose
ASA, steroids, estrogen
Increased levels—antiHTN meds, digitalis
preps, cholinergic
agents, INH, oral
contraceptives
Liver enzyme
Aids in dx of liver dz—
how injured is the
liver? Identify and
monitor hepatocellular
dz, compare with AST
to determine cause of
liver dz
AST (Aspartate
Aminotransferase)
Liver function test
ALT (Alanine
Aminotransferase)
Liver function test
Hepatocellular dz,
coronary occlusive
heart dz, first enzyme
to change with injury,
acute extra hepatic
obstruction
Increased levels—
acetaminophen, allopurinol,
amicillin, cephalosporins,
chlorproamide, codeine,
INH, methyldopa, oral
contraceptives, phenytoin,
propranolol, salicylates
Causes—malnutrition,
malabsorption,
hypoparathyroid,
chronic renal tubular
dz, DKA, toxemia of
pregnancy
Signs/symptoms—
cramping, tremor,
hyperreflexia,
convulsions, delirium
Causes—Increased
renal excretion,
Fanconi’s syndrome,
lead poison, x-ray
contrast agents, severe
liver dysfunction,
Wilson’s disease
Acute renal dz, chronic
renal dz, pregnancy,
DKA
None.
Causes—renal
insufficiency, ingestion
of Mg, hypothyroid,
hyporeflexia.
Signs/symptoms—N/V,
weakness, slurred
speech, decreased
reflexes, cardiac arrest,
respiratory depression
Causes—increased
production in liver,
ingestion of purines,
renal disease,
hyperlipoproteinemia,
shock, large blood loss,
alcoholism
Heart dz, liver dz
(hepatitis, cirrhosis),
skeletal muscle dz,
trauma, surgery, burns,
acute hemolytic
anemia, acute
pancreatitis,
hepatobiliary dz
Hepatocellular dz,
cholestasis, obstructive
jaundice, severe burns,
striated muscle
trauma, hepatotoxic
drugs. Mild increases—
myositis, pancreatitis,
infx mono, shock.
LDH (Lactic acid
dehydrogenase)
Hepatic and cardiac
marker. LDH1 = heart,
LDH2 =
reticuloendothelial
system, LDH3 =
pulmonary, LDH4 =
kidney/pancreas, LDH5
= liver/skeletal muscle
Enzyme found in the
liver, bone, and biliary
tract epithelium.
Least sensitive and
specific. Isoenzymes
are specific for certain
dz/disorders
None.
None.
Increases in all mean
multisystem organ
failure.
Detection of bone and
liver disorders. Most
sensitive test for tumor
metastasis to the liver
(ALP1). Bone disease
(ALP2).
Hypophosphatemia,
malnutrition,
pernicious anemia
(decreased B12)
Primary cirrhosis,
intra/extrahepatic
biliary obstruction,
liver tumor, pregnancy,
bones of growing kids,
bone tumors, healing
fracture, Paget’s dz
GGT (GammaGlutamyltransferase)
Most sensitive and
specific to the liver.
Marker of biliary
obstruction.
None.
Liver dz, MI, alcohol
ingestion, pancreatic
dz, infx mono—EBV
Bilirubin
Liver function.
ALP increase paralleled
with GGT =
hepatobiliary dz.
Normal GGT
w/increase in ALP =
skeletal dz. Chronic
alcohol ingestion.
Hepatocellular dz,
biliary obstruction,
extrahepatic dz,
hemolysis, cause of
jaundice.
Increased levels—
allopurinol, albumin from
placental tissue, antibx,
colchicines, INH,
probenecid, verapamil
Decreased levels—
cyanides, fluorides,
oxalates, zinc salts, gout
meds (NSAIDs)
Increased levels—alcohol,
phenytoin,
phenobarbitol.
Decreased levels—oral
contraceptives
None.
None.
Increased indirect—
prehepatic dz.
Increased direct—
extrahepatic duct
obstruction, extensive
liver metastasis,
congenital defect of
liver enzyme quality.
Increased total
bilirubin—hepatic dz.
ALP (Alkaline
phosphatase)
Ammonia (NH4+)
By product of protein
metabolism.
Support/monitoring of
severe liver dz/dx.
Follow up of hepatic
encephalopathy
None
None
Eryhtroblastosis fetalis,
hepatocellular dz,
Reye’s syndrome,
portal HTN, GI bleed,
GI obstruction with
mild liver dz, hepatic
encephalopathy.
Amylase
Enzyme secreted from
pancreatic acinar cells
into pancreatic duct
and then into
duodenum—aid in
catabolism of carbs.
Acute abdominal
pain/detection
/monitoring of
pancreatitis—sensitive
but not specific to
pancreatitis
Increased levels—ASA,
corticosteroids, ethyl
alcohol, glucocorticoids,
loop diuretics, oral
contraceptives,
prednisone
Bowel perforation,
PUD, GI dz (duodenal
obstruction), acute
cholecystitis, renal
failure. Salivary
amylase parotiditis,
sialitis, sialolithiasis,
Lipase
Break down
triglycerides into fatty
acids.
Pancreatic function.
Increased levels—
codeine, indomethacin,
meperidine, morphine
Patients with
pancreatic cell
destruction or massive
hemorrhagic
pancreatic necrosis—
decrease in cells
available to make
amylase.
None.
Albumin
Protein that is formed
in the liver. Maintains
serum oncotic
pressure, transports
drugs, hormones, and
enzymes.
Diagnose, evaluate,
monitor dz courses of
pts with: cancer,
intestinal/renal protein
wasting states,
immune disorders, liver
dysfunction, impaired
nutrition
Increased levels—
anabolic steroids,
androgens,
corticosteroids, dextran,
growth hormone, insulin,
progesterone
Decreased levels—
ammonium ions,
estrogens, hepatotoxic
drugs, oral contraceptives
Direct loss, pregnancy,
starvation, liver dz.
Dehydration only
Pancreatitis. Will
parallel amylase levels.
Biliary dz, renal failure,
intestinal dz, salivary
gland
inflammation/tumor,
PUD
Globulin
3 groups: 
Key building blocks of:
Glycoproteins,
lipoproteins,
immunoglobulin,
clotting factors
Main transport
molecule. Maintain
osmotic pressure.
Measure nutrition,
detect neoplasms or
infections. Monitor/dx
cancer, liver dz,
impaired nutrition,
chronic edematous
states. Tested for with
albumin
Fluctuations caused by:
ASA, bicarbonates,
chlorpromazine,
corticosteroids, INH,
neomycin, phenacemide,
salicylates, sulfonamides,
tolbutamides
PAP (Prostatic Acid
Phosphate)
Isoenzyme of total acid
phosphatase and is
found in the prostate
gland.
Detection, staging,
monitoring response to
tx in prostate cancer
(esp. metastasis)—not
elevated in all cancers.
PSA preferred over
PAP.
CPK/CP/CK (creatine
phosphokinase)
Found on cells of 3
major systems—heart,
skeletal muscle,
brain—all secrete
specific isoenzyme of
CPK heart = CPK-MB,
brain = CPK-BB, muscle
= CPK-MM
Enzyme that denotes
tissue insult or injury.
Increased levels—S/P
prostatic manipulation,
increased alkaline
phosphatase conditions,
androgens, clofibrate.
Decreased levels—
fluorides, phosphates,
heparin, EtOH, oxalates
Increased levels—IM
injection, vigorous
exercise, recent surgery,
pregnancy, increased
muscle mass.
Amphoterocin B, HMGCoA reductase inhibitors,
fibric acid derivatives,
ASA, EtOH, lidocaine,
succinylcholine,
dexamethasone,
ampicillin, anticoagulants
Elevated 2 = early
stage infx, MI, tissue
necrosis (decreased
albumin)
Elevated2 = chronic
infx, cirrhosis
(decreased albumin)
Elevated 2,  =
nephritic syndrome
(decreased albumin)
None.
None.
None.
CPK-MM—IM injection, recent
surgery, shock, delirium
tremens, strenuous exercise,
crush injury/trauma, ECT,
convulsive disorder,
rhabdomyolysis, MD, myositis
CPK-MB—Acute MI, cardiac
contusion, cardiomyopathy,
myocarditis, unstable angina
CPK-BB—head trauma/brain
injury, ECT, brain tumor, CVA,
seizure disorder, intracerebral
hemorrhage, shock, Reye’s
syndrome, lung/breast cancer,
PE
Prostate cancer, BPH,
prostatitis, multiple
myeloma, Paget’s dz,
hyperparathyroid,
sickle cell, liver
dysfunction.
Fasting glucose
Fuel for the body.
Diabetes diagnoses.
Synthesized by the liver
via gluconeogenosis
and by the breakdown
of fats and proteins via
lipases and proteases.
HgB-A1C (Hemoglobin
A1C)
Present in RBCs for
entire life span—up to
3 months. This HgB is
specifically receptive to
blood glucose. Greater
amount of glucose RBC
exposed to, higher
HgB-A1C
Measure long term
glucose control.
Increased levels—stress,
caffeine, postprandial,
pregnancy (gestational
diabetes), D5W, TCAs, blockers, steroids, INH,
antipsychotics,
phenytoin, diuretics,
glucagon, salicylates,
epinephrine, estrogen.
Decreased levels—APAP,
EtOH, insulin,
propranolol, MAOIs
N/A
Insulinoma,
hypothyroid,
hypopituitarism,
Addison’s dz, liver
failure, insulin
overdose, poor intake
of food
Diabetes mellitus—FPG >126
mg/dL on 2+ occasions—
signs/symptoms = polyuria,
polydyspnea, polyphagia.
Acute stress, Cushing’s
syndrome, pheochomocytoma,
CRF, acute pancreatitis,
acromegaly, hyperthyroidism,
corticosteroids, diuretic
therapy
N/A
N/A