Electrolytes Flashcards
What are cations?
Positively charged ion
What are electrolytes?
Charged ions found in extra/inter cellular and interstitial fluid
Major cations in the body? (4)
Sodium, Potassium, Calcium and Magnesium
What are anions?
Negatively charged ions
What are the major anions found within the body? (6)
Chloride, phosphate, bicarbonate, sulfate, protein and organic acids
clinically, what electrolytes are often measured?
Sodium, potassium, chloride and total carbon dioxide or bicarbonate
What method is used to measure electrolytes such as sodium potassium chloride and bicarbonate?
Ion selective electrode
Major cation of extra cellular fluid
Sodium
Reference range for sodium
136-145 mmol/liter
Changes in sodium results in a change in what
Plasma volume
Largest contributor for plasma osmolality
Sodium
Renal threshold value for sodium
110-130mmol/liter
Condition when serum sodium is below 135mmol/liter
Hyponatremia
Two types of hyponatremia
Delpletional and dilutional
Depletional hyponatremia occurs in
Diarrhea, vomiting, severe burns/trauma hypoaldosteronism or Addison’s disease, diuretics
What are the causes of dilutional hyponatremia
Over rehydration, syndrome of inappropriate anti diuretic hormone ( SIADH), congestive heart failure, cirrhosis and nephrotic syndrome
Condition when serum sodium is above 150mmol/liter
Hypernatremia
When does hypernatremia occur
Diarrhea, excessive sweating, diabetes insipidus, hyperaldosteronism, iv infusion, ingestion
Major intracellular cation
Potassium
Reference range for potassium
3.4-5.0
Level of potassium when specimen is hemolysis
Increased
Condition when potassium is below 3.0mmol/liter
Hypokalemia
Hypokalemia occurs in
Decreased intake, hyperaldosteronism, diuretics, vomiting, diarrhea, laxative abuse, excess insulin
Condition where potassium level is greater than 5.0 mmol/liter
Hyperkalemia
What are the causes of hyperkalemia
Increased intake, hypoaldosteronism, metabolic acidosis, increased RBI lysis, leukemia, chemotherapy.
Major anion of the extracellular fluid
Chloride
Reference range for chloride
98-107 mmol/liter
Occurs when serum chloride is below 98
Hypochloremia
Occurs when chloride level is above 107mmol/liter
Hyperchloremia
Hypochloremia results from what conditions
Excessive vomiting, use of diuretics, burns aldosterone
Hyperchloremia results from what conditions
Prolonged diarrhea, renal tubular disorder, dehydration, excess loss of bicarbonate
Second largest anion fraction of the extracellular fluid
Bicarbonate
Reference range for bicarbonate
22-29mmol/liter
ctCO2 is comprised of what
HCO3, H2CO3, carbamino. Bound CO2, dissolved CO2
Clinical significance for low bicarbonate
Metabolic acidosis, diabetic ketoacidosis, salicylate toxicity
Clinical significance for high bicarbonate
Metabolic alkalosis, emphysema, vomiting
Formula used to demonstrate the electro neutrality in body fluids
Anion gap
Two formulas for computing anion gap
Na - (Cl + HCO3) = anion gap
Na + K - ( Cl + HCO3) = anion gap
Reference range for anion gap if formula used does not contain potassium
7-16 mmol/liter
Reference range for anion gap if formula used contains potassium
10 - 20mmol/liter