Electrolyte Imbalances

Physical examination: 1. anorexia 2. nausea and vomiting 3. constipation 4. fatigue 5. diminished reflexes 6. lethargy 7. Decreased level of consciousness 8. Confusion 9. Personality change 10. Cardiac dysrhythmias 11. Possible flank pain from renal calculi 12. Hypercalcemia caused by shift of calcium from bone: pathological fractures 13. Signs of digoxin toxicity at normal digoxin levels

Hypercalcemia

High serum potassium level

Hyperkalemia

Laboratory findings: 1. Serum K+ level greater than 5 mmol/L 2. Possible ECG abnormalities

Hyperkalemia

Physical examination: 1. Bilateral muscle weakness in quadriceps 2. Transient abdominal cramps and diarrhea 3. Cardiac dysrhythmias 4. Cardiac arrest

Hyperkalemia

High serum magnesium level

Hypermagnesemia

Laboratory findings: 1. Serum Mg2+ level greater than 1.25 mmol/L 2. Possible ECG abnormalities

Hypermagnesemia

Physical examination: 1. Lethargy 2. Hypoactive deep tendon flexes 3. Bradycardia 4. Hypotension 5. Acute elevation in magnesium levels: flushing, sensation of warmth 6. Severe hypermagnesemia: flaccid muscle paralysis 7. Decreased rate and depth of respirations 8. Cardiac dysrhythmias 9. Cardiac arrest

Hypermagnesemia

Laboratory findings: 1. Total serum Calcium less than 2.1 mmol/L 2. Ionized Calcium level less than 1.1 mmol/L 3. Possible ECG abnormalities

Hypocalcemia

Low serum calcium level

Hypocalcemia

Physical examination: 1. Positive Chvostek's sign (contraction of facial muscles when facial nerve is tapped) 2. Positive Trousseau's sign (carpal spasm with hypoxia), 3. Numbness and tingling of fingers and circumoral (around mouth) region 4. Hyperactive reflexes 5. Muscle twitching and cramping 6. Tetany 6. Seizures 7. Laryngospasm 8. Cardiac dysrhythmias

Hypocalcemia

Laboratory findings: 1. Serum K+ level less than 3.5 mmol/L 2. Possible ECG abnormalities

Hypokalemia

Low serum potassium (K+) level

Hypokalemia

Physical examination: 1. Bilateral muscle weakness that begins in the quadriceps and may ascend to respiratory muscles 2. Abdominal distention 3. Decreased bowel sounds 4. Constipation 5. Cardiac dys rhythmias 6. Signs of digoxin toxicity at normal digoxin levels

Hypokalemia

Laboratory findings: Serum Mg2+ level less than 0.75 mmol/L

Hypomagnesemia

Low serum magnesium level

Hypomagnesemia

Physical examination: 1. Positive Chvostek's and Trousseau's signs 2. Hyperactive deep tendon reflexes 3. Insomnia 4. Muscle cramps and tetany 5. Seizures 6. Cardiac dysrhythmias 7. Signs of digoxin toxicity at normal digoxin levels

Hypomagnesemia

Milk-alkali syndrome

Increased calcium intake and absorption (hypercalcemia)

1. Steatorrhea 2. Chronic diarrhea

Increased calcium output (hypocalcemia)

High serum calcium level

Hypercalcemia

Adrenal insufficiency

Decreased K+ & Mg 2+ output (hyperkalemia, hypermagnesemia)

Excessive use of potassium-free IV solutions

Decreased K+ intake and absorption (hypokalemia)

Acute or chronic oliguria (e.g. ECV deficit, end-stage renal disease)

Decreased K+ output (hyperkalemia)

Adrenal insufficiency

Decreased K+ output (hyperkalemia)

Use of potassium-sparing diuretics

Decreased K+ output (hyperkalemia)

1. Malnutrition 2. Chronic alcoholism 3. Chronic diarrhea, laxative misuse 4. Steatorrhea (e.g. pancreatitis)

Decreased Mg2+ intake and absorption (hypomagnesemia)

1. Calcium-deficient diet 2. Vitamin D deficiency (includes end-stage renal disease) 3. Chronic diarrhea, laxative misuse 4. Steatorrhea (e.g. pancreatitis)

Decreased calcium intake and absorption (hypocalcemia)

Use of thiazide diuretics

Decreased calcium output (hypercalcemia)

1. End-stage renal disease 2. Adrenal insufficiency

Decreased magnesium output (hypermagnesemia)

Laboratory findings: 1. Total serum calcium greater than 2.6 mmol/L 2. Serum ionized calcium greater than 1.3 mmol/L 3. Possible ECG abnormalities

Hypercalcemia

Aldosterone excess

Increased K+ & Mg2+ output (hypokalemia & hypomagnesemia)

Excessive ingestion of K+ salt substitutes

Increased K+ intake and absorption (hyperkalemia)

Iatrogenic administration of large amounts of IV potassium

Increased K+ intake and absorption (hyperkalemia)

Rapid infusion of stored blood

Increased K+ intake and absorption (hyperkalemia)

Acute or chronic diarrhea, vomiting, or other GI losses

Increased K+ output (hypokalemia)

Glucocorticoid therapy

Increased K+ output (hypokalemia)

Polyuria

Increased K+ output (hypokalemia)

Use of potassium-wasting diuretics

Increased K+ output (hypokalemia)

1. Excessive use of magnesium-containing laxatives and antacids 2. Parenteral overload of magnesium

Increased Mg2+ intake and absorption (hypermagnesemia)

1. Aldosterone excess 2. Use of thiazide or loop diuretics 3. Steatorrhea, chronic diarrhea or other GI losses

Increased Mg2+ output (hypomagnesemia)

1. Prolonged immobilization 2. Hyperparathyroidism 3. Bone tumors 4. Nonosseous cancers that secrete bone-resorbing factors

Shift if calcium from bone into ECF (hypercalcemia)

Rapid administration of citrated blood

Shift of Mg2+ into inactive form (hypomagnesemia)

1. Hypoparathyroidism 2. Rapid administration of citrated blood 3. Hypoalbuminemia 4. Alkalosis 5. Hyperphosphatemia (includes end-stage renal disease)

Shift of calcium from ECF into bone or inactive form (hypocalcemia)