Hypophosphatemia in Emergency Medicine Treatment & Management
- Author: Devon J Moore, MD; Chief Editor: Erik D Schraga, MD more...
Emergency Department Care
- Treatment of hypophosphatemia is twofold.
- Correct any precipitating causes of hypophosphatemia.
- Replace total body phosphates.
- Depending on the clinical situation, replacement options include dietary phosphate, oral phosphate preparations, and IV phosphate.
- Hypophosphatemia and hypokalemia can coexist in certain disorders like diabetic ketoacidosis and alcoholism, so replacement with the potassium salt is most appropriate.
- The most important consideration in choosing replacement therapy is whether the patient has signs or symptoms of phosphate depletion.
- Mild to moderately severe, asymptomatic hypophosphatemia
- Mild to moderately severe, asymptomatic hypophosphatemia may require oral phosphate replacement; however, correcting factors that led to the hypophosphatemia usually is sufficient.
- In most asymptomatic patients, the serum phosphate level spontaneously normalizes over several days when factors inducing hypophosphatemia are corrected.
- In patients with minimal symptoms or moderate hypophosphatemia (serum phosphate 1-2 mg/dL), providing oral phosphate replacement may be desirable.
- The average adult consumes 1 gram of phosphorus daily. A quart of cow's milk provides this amount of phosphorus (1 mg phosphorus/mL). Dairy products have an additional advantage of supplying absorbable calcium, which can help avoid the hypocalcemia that may result with more aggressive replacement regimens.
- Phosphorus preparations with sodium and potassium are available, but they have disadvantages, including causing osmotic diarrhea, volume overload, or hyperkalemia.
- Usual starting doses are 2-3 grams of elemental phosphorus in divided doses.
- Severe/symptomatic hypophosphatemia
- Patients with symptoms of hypophosphatemia or with serum phosphate levels less than 1 mg/dL require IV phosphate replacement.
- The intracellular nature of phosphate makes interpreting a low serum phosphate level difficult and predicting the amount required to replenish cellular stores nearly impossible.
- Accordingly, recommendations for IV phosphate in the literature are varied and based on therapeutic experiences with limited numbers of patients.
- Avoid hyperphosphatemia when replacing phosphorus intravenously, as this can lead to hypocalcemia (leading to tetany) and calcium-phosphate deposition in tissues (eye, heart, kidney, lung).
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