Unit 2: Elecytolytes Flashcards
(68 cards)
DETERMINATION OF OSMOLALITY
Spx
Serum
Urine
OSMOLALITY
METHODS
Osmometers
Osmometer principle
Freezing point depression
Major cation of extracellular fluid
o 90% of all extracellular cation
o Most abundant
SODIUM (NATRIUM)
Most common electrolyte disorder in hospitalized and non-
hospitalized.
Hyponatremia
Decreased sodium levels may be caused by:
increased
sodium loss, increased water retention, or water imbalance
Increased sodium loss
oCertain diuretics (thiazides)
o Ketonuria
o Salt-losing nephropathy
o K+ deficiency
o Prolonged vomiting and diarrhea
o Severe burns
Increased water retention
o Acute or chronic renal failure
o Nephrotic syndrome
o Hepatic cirrhosis
o Congestive heart failure
• Water imbalance
o Excess water intake; Polydipsia
o SIADH (Syndrome of inappropriate ADH secretion)
o Pseudohyponatremia
o Diabetes mellitus
o excess levels of glucose in the
plasma or serum
Hyponatremia with a high osmolality
Increase in non-sodium cations
Hyponatremia with a normal osmolality
sodium loss or water retention
Hyponatremia with a low osmolality
Sodium Spx
Serum, plasma, and urine
Sodium
anticoagulants
lithium heparin, ammonium heparin, and lithium oxalate
Urine sodium analysis spx
24 hr collection
Used for sodium determination
Sweat
Methods in Sodium
ION SELECTIVE ELECTRODES
COLORIMETRY
Others
Emission Flame Photometry
Atomic Absorption Spectrometry (AAS)
The major intracellular cation in the body
POTASSIUM (KALIUM)
Spx in potassium determination
Seru
Plasma
Urine
Sodium
Ion Selective Exchange
Glass ion exchange
SODIUM
2 types of ISE method
Direct
Indirect
undiluted sample interacts with the ISE membrane (glass aluminum
silicate)
ISE DIRECT METHOD
DIRECT ISE MEMBRANE
Glass aluminum silicate
a diluted sample is used for measurement
ISE INDIRECT METHOD
