Electrolyte Summary

Sodium

Major Extracellular Cation

Sodium Range

136-145 mEq/L

Potassium

Major Intracellular Cation

Potassium Range

2.5-5.1 mEq/L

Chloride

Major Extracellular Anion

Chloride Range

98-107 mEq/L

Bicarbonate

Most important Extracellular Anion

Bicarbonate Range

23-29 mEq/L

Calcium Range

8.5-10.5 mEq/L

Magnesium

Second most abuntant intracellular cation

Magnesium Range

1.9-2.5 mg/dL

Phosphorus

ONLY major intracellular anion

Phosphorus Range

2.5-4.5 mg/dL

Anion Gap Range with K+

16 +/- 4 mEq/L

Anion Gap Range without K+

12 +/- 4 mEq/L

Serum Osmolality Range

280-300 mOsm/kg

Urine Osmolality Range

300-1000 mOsm/kg

Sodium Functions

- Maintenance of water distribution

- Maintenance of normal osmotic pressure

- Neuromuscular processes

- Acid-base balance

Sodium Causes for Increase

Water loss, sodium gain

Sodium Causes for Decrease

Depletional, Dilutional, Pseudohyponatremia

Potassium Functions

- Regulation of cellular processes

- Neuromuscular excitation

Potassium Causes for Increase

- Increased intake

- Increased cell lysis

- Impaired renal excretion

- Pseudohyperkalemia

- Altered cellular uptake

Potassium Causes for Decrease

- Increased cellular uptake

- Increased renal loss

- Increased GI loss

Chloride Functions

- Maintenance of water distribution

- Maintence of normal osmotic pressure

- Acid-base balance

Chloride Causes for Increase

- Dehyrdation

- Metabolic alkalosis compensation

Chloride Causes for Decrease

- GI loss, burns, renal loss

Bicarbonate Function

- Blood buffer

Bicarbonate Cause for Increase

- Metabolic alkalosis

Bicarbonate Cause for Decrease

- Metabolic acidosis

Calcium Functions

- Decrease neuromuscular excitability

- Coagulation

- Enzyme activator

- Transfer of ions across cell membranes

- Neurotransmitter release

Calcium Causes for Increase

- Metastatic bone disease

- Hyperparathyroidism

- Multiple Myeloma

Calcium Causes for Decrease

- Decreased serum [protein]

- Hypoparathyroidism

- Vitamin D deficiency

- Steatorrhea

- Nephrosis

- Pancreatitis

Magnesium Functions

- Required activator in enzymatic reactions related to ATP

- Cellular physiology

- Role in carbohydrate, lipid, protein, and nucleic acid metabolism

Magnesium Causes for Increase

- Renal failure

- Magnesium intoxication

- Treatment for toxemia of pregnancy

Magnesium Causes for Decrease

- Impaired intake

- Excessive renal loss

Phosphorus Functions

- Intermediary metabolism of carbohydrates

- Component of other structures

- Bone mineralization

- Minor blood buffer

Phosphorus Causes for Increase

- Glomerular renal failure

- Hypoparathyroidism

- Hypervitaminosis D

- Bone repair

Phosphorus Causes for Decrease

- Rickets

- Fanconi syndrome

- Hyperparathyroidism

- Hemolytic anemia

- Diabetes mellitus