Hypophosphatemia in Emergency Medicine Treatment & Management
- Author: Luda Khait, MD, MS; Chief Editor: Erik D Schraga, MD more...
Emergency Department Care
Treatment of hypophosphatemia is twofold. 1) correct any precipitating causes of hypophosphatemia, and 2) replace total body phosphates.
- Depending on the clinical situation, replacement options include dietary phosphate, oral phosphate preparations, and IV phosphate.
- Replacement of phosphate is recommended through the intravenous route in patients with severe hypophosphatemia and for patients that concomitantly have cardiac dysfunction, respiratory failure, muscle weakness, or impaired tissue oxygenation.
- 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.
- It is recommended that oral phosphate replacement be used in patients who are symptomatic and have phosphate levels between 1.0-1.9 mg/dL.
- For patients who are symptomatic and have a serum phosphate level less than 1.0 mg/dL, IV replacement is recommended, followed by oral replacement once serum phosphate levels reach greater than 1.5 mg/dL.
- 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.
- IV replacement can be dangerous for the patient, causing an electrolyte disturbances including hypocalcemia, renal failure from calcium phosphate precipitating in the kidneys, and fatal arrhythmias.
- Serum phosphate concentration should be monitored every 6 hours if replacement is given through the IV route.
- Once serum phosphate levels reach 1.5 md/dL, therapy should be switched to oral 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).
Based on any underlying or suspected etiologies
Tejeda A, Saffarian N, Uday K, Dave M. Hypophosphatemia in end stage renal disease. Nephron. 1996. 73(4):674-8. [Medline].
Camp MA, Allon M. Severe hypophosphatemia in hospitalized patients. Miner Electrolyte Metab. 1990. 16(6):365-8. [Medline].
Liamis G, Milionis HJ, Elisaf M. Medication-induced hypophosphatemia: a review. QJM. 2010 Jul. 103(7):449-59. [Medline].
Brautbar N, Leibovici H, Massry SG. On the mechanism of hypophosphatemia during acute hyperventilation: evidence for increased muscle glycolysis. Miner Electrolyte Metab. 1983 Jan-Feb. 9(1):45-50. [Medline].
Datta BN, Stone MD. Hyperventilation and hypophosphataemia. Ann Clin Biochem. 2009 Mar. 46:170-1. [Medline].
Becker S, Dam G, Hvas CL. Refeeding encephalopathy in a patient with severe hypophosphataemia and hyperammonaemia. Eur J Clin Nutr. 2014 Nov 12. [Medline].
Mehanna H, Nankivell PC, Moledina J, Travis J. Refeeding syndrome - awareness, prevention and management. Head Neck Oncol. 2009 Jan 26. 1(1):4. [Medline].
Nowik M, Picard N, Stange G, Capuano P, Tenenhouse HS, Biber J, et al. Renal phosphaturia during metabolic acidosis revisited: molecular mechanisms for decreased renal phosphate reabsorption. Pflugers Arch. 2008 Nov. 457(2):539-49. [Medline].
Bodenhamer J, Bergstrom R, Brown D, Gabow P, Marx JA, Lowenstein SR. Frequently nebulized beta-agonists for asthma: effects on serum electrolytes. Ann Emerg Med. 1992 Nov. 21(11):1337-42. [Medline].
Tenenhouse HS. Phosphate transport: molecular basis, regulation and pathophysiology. J Steroid Biochem Mol Biol. 2007 Mar. 103(3-5):572-7. [Medline].
Hu CY, Lee BJ, Cheng HF, Wang CY. Acetazolamide-related Life-threatening Hypophosphatemia in a Glaucoma Patient. J Glaucoma. 2014 Oct 20. [Medline].
Rastegar A. New concepts in pathogenesis of renal hypophosphatemic syndromes. Iran J Kidney Dis. 2009 Jan. 3(1):1-6. [Medline].
Faroqui S, Levi M, Soleimani M, Amlal H. Estrogen downregulates the proximal tubule type IIa sodium phosphate cotransporter causing phosphate wasting and hypophosphatemia. Kidney Int. 2008 May. 73(10):1141-50. [Medline].
Bates JA. Phosphorus: a quick reference. Vet Clin North Am Small Anim Pract. 2008 May. 38(3):471-5, viii. [Medline].
King AL, Sica DA, Miller G, Pierpaoli S. Severe hypophosphatemia in a general hospital population. South Med J. 1987 Jul. 80(7):831-5. [Medline].
Travis SF, Sugerman HJ, Ruberg RL, Dudrick SJ, Delivoria-Papadopoulos M, Miller LD, et al. Alterations of red-cell glycolytic intermediates and oxygen transport as a consequence of hypophosphatemia in patients receiving intravenous hyperalimentation. N Engl J Med. 1971 Sep 30. 285(14):763-8. [Medline].
Knochel JP. Hypophosphatemia and rhabdomyolysis. Am J Med. 1992 May. 92(5):455-7. [Medline].
Davis SV, Olichwier KK, Chakko SC. Reversible depression of myocardial performance in hypophosphatemia. Am J Med Sci. 1988 Mar. 295(3):183-7. [Medline].
Sebastian S, Clarence D, Newson C. Severe hypophosphataemia mimicking Guillain-Barré syndrome. Anaesthesia. 2008 Aug. 63(8):873-5. [Medline].
Taylor BE, Huey WY, Buchman TG, Boyle WA, Coopersmith CM. Treatment of hypophosphatemia using a protocol based on patient weight and serum phosphorus level in a surgical intensive care unit. J Am Coll Surg. 2004 Feb. 198(2):198-204. [Medline].
Bastepe M, Juppner H. Inherited hypophosphatemic disorders in children and the evolving mechanisms of phosphate regulation. Rev Endocr Metab Disord. 2008 Jun. 9(2):171-80. [Medline].
Crook MA. Management of severe hypophosphatemia. Nutrition. 2009 Mar. 25(3):368-9. [Medline].
Domrongkitchaiporn S, Disthabanchong S, Cheawchanthanakij R, Niticharoenpong K, Stitchantrakul W, Charoenphandhu N, et al. Oral Phosphate Supplementation Corrects Hypophosphatemia and Normalizes Plasma FGF23 and 25-Hydroxyvitamin D3 Levels in Women with Chronic Metabolic Acidosis. Exp Clin Endocrinol Diabetes. 2009 May 15. [Medline].
Fukumoto S. Physiological regulation and disorders of phosphate metabolism--pivotal role of fibroblast growth factor 23. Intern Med. 2008. 47(5):337-43. [Medline].
Ghosh AK, Joshi SR. Disorders of calcium, phosphorus and magnesium metabolism. J Assoc Physicians India. 2008 Aug. 56:613-21. [Medline].
Juppner H. Novel regulators of phosphate homeostasis and bone metabolism. Ther Apher Dial. 2007 Oct. 11 Suppl 1:S3-22. [Medline].
Laaban JP, Waked M, Laromiguiere M, Vuong TK, Rochemaure J. Hypophosphatemia complicating management of acute severe asthma. Ann Intern Med. 1990 Jan 1. 112(1):68-9. [Medline].
Moe SM. Disorders involving calcium, phosphorus, and magnesium. Prim Care. 2008 Jun. 35(2):215-37, v-vi. [Medline].
Oud L. Transient hypoxic respiratory failure in a patient with severe hypophosphatemia. Med Sci Monit. 2009 Mar. 15(3):CS49-53. [Medline].
Shiber JR, Mattu A. Serum phosphate abnormalities in the emergency department. J Emerg Med. 2002 Nov. 23(4):395-400. [Medline].
Squara P, Bleichner G, Aubier M, Parent A, Sollet JP, Murciano D. [Hypophosphoremia during mechanical ventilation for chronic obstructive bronchopathies]. Presse Med. 1985 Jun 1. 14(22):1225-8. [Medline].