NORMAL ACID-BASE REGULATION

a. Reduced absorption/intake

- Malabsorption syndrome

- Prolonged IV therapy (without magnesium)

- Protein-energy malnutrition

b. Increased urinary losses

- Hypoparathyroidism

- Renal tubular acidosis

- Nephrotoxic drugs

- Hyperaldosteronism

- Hypercalcemia

c.

d. Others: Bartter syndrome, mitochondrial disorders

magnesium), diluted 5-10 times in normal saline, which may be repeated every 6 hours to the maximum of 200 mg/kg/day. Lower doses should be used in cases with renal disease. Concurrent hypocalcemia and hypokalemia also needs correction. Asymptomatic cases may be treated with oral magnesium supplements.

Hypermagnesemia is uncommon, sometimes seen in cases with chronic kidney disease or prolonged used of magnesium containing antacids. Symptoms are non-specific with nausea, vomiting and weakness in milder cases, though severe cases may develop altered sensorium, respiratory depression and arrhythmia.

Treatment involves removal of the source along with IV calcium therapy in severe cases to antagonize cardiac and neuromuscular effects of extracellular magnesium excess. Rarely, dialysis may be needed in very severe and symptomatic hypermagnesemia.

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