Hyperphosphatemia: Difference between revisions

{{distinguish|text=[[hypophosphatemia]] (low phosphate levels in the blood)}}

| image = Phosphate Group.PNGsvg

'''Hyperphosphatemia''' is an [[electrolyte disorder]] in which there is an elevated level of [[phosphate]] in the [[blood]].<ref name=Mer2018/> Most people have no symptoms while others develop [[ectopic calcification|calcium deposits]] in the soft tissue.<ref name=Mer2018/> OftenThe theredisorder is alsooften accompanied by [[low calcium]] blood levels, which can result in muscle spasms.<ref name=Mer2018>{{cite web |title=Hyperphosphatemia |url=https://www.merckmanuals.com/professional/endocrine-and-metabolic-disorders/electrolyte-disorders/hyperphosphatemia |website=Merck Manuals Professional Edition |accessdateaccess-date=27 October 2018}}</ref>

Causes include [[kidney failure]], [[pseudohypoparathyroidism]], [[hypoparathyroidism]], [[diabetic ketoacidosis]], [[tumor lysis syndrome]], and [[rhabdomyolysis]].<ref name=Mer2018/> Diagnosis is generally based on a blood phosphate levelslevel of greater thanexceeding 1.46&nbsp;mmol/L (4.5&nbsp;mg/dL).<ref name=Mer2018/> When levels are greater than 4.54 mmol/L (14 mg/dL) it is deemed severe.<ref name=Ad2012>{{cite book |last1=Adams |first1=James G. |title=Emergency Medicine: Clinical Essentials (Expert Consult - Online and Print) |date=2012 |publisher=Elsevier Health Sciences |isbn=1455733946 |page=1416 |url=https://books.google.ca/books?id=rpoH-KYE93IC&pg=PA1416 |language=en}}</ref> Levels may appear falsely elevated with [[dyslipidemia|high blood lipid levels]], [[hyperproteinemia|high blood protein levels]], or [[hyperbilirubinemia|high blood bilirubin levels]].<ref name=Mer2018/>

Treatment may include eating a phosphate low diet and [[antacids]], like [[calcium carbonate]], that bind phosphate.<ref name=Mer2018/> Occasionally, intravenous [[normal saline]] or [[kidney dialysis]] may be used.<ref name=Mer2018/> How commonly it occurs is unclear.<ref name=Ron2008>{{cite book |last1=Ronco |first1=Claudio |last2=Bellomo |first2=Rinaldo |last3=Kellum |first3=John A. |title=SPEC - Critical Care Nephrology Expert Consult (Book Program) Pincard |date=2008 |publisher=Elsevier Health Sciences |isbn=1437711111978-1437711110 |page=533 |url=https://books.google.cacom/books?id=MdgvSwnlgRgC&pg=PA533 |language=en}}</ref>

Signs and symptoms include [[ectopic calcification]], secondary [[hyperparathyroidism]], and [[renal osteodystrophy]]. Abnormalities in phosphate metabolism such as hyperphosphatemia are included in the definition of the new [[chronic kidney disease-mineraldisease–mineral and bone disorder]] (CKD-MBDCKD–MBD).<ref>{{Cite journal|url = http://kdigo.org/home/mineral-bone-disorder/|title = KDIGO Guideline for Chronic Kidney Disease-Mineral and Bone Disorder (CKD-MBD)|last = |first = |date = |journal = |doi = |pmid = |access-date = 7 February 2016|archive-url = https://web.archive.org/web/20170304114556/http://kdigo.org/home/mineral-bone-disorder/|archive-date = 4 March 2017|url-status = dead}}</ref>

[[Hypoparathyroidism]]: In this situation, there are low levels of [[parathyroid hormone]] (PTH). PTH normally inhibits reabsorption of phosphate by the kidney. Therefore, without enough PTH there is more reabsorption of the phosphate leading to a high phosphate level in the blood.{{citation needed|date=June 2022}}

[[Chronic kidney failure]]: When the kidneys are not working well, there will be increased phosphate retention.{{citation needed|date=June 2022}}

The diagnosis of hyperphosphatemia is made through measuring the concentration of phosphate in the blood. A phosphate concentration greater than 1.46 &nbsp;mmol/lL (4.5 &nbsp;mg/dldL) is indicative of hyperphosphatemia, though further tests may be needed to identify the underlying cause of the elevated phosphate levels.<ref name="Merck Manual Hyperphos">{{cite web|title=Hyperphosphatemia - Endocrine and Metabolic Disorders - Merck Manuals Professional Edition|url=http://www.merckmanuals.com/professional/endocrine-and-metabolic-disorders/electrolyte-disorders/hyperphosphatemia|website=Merck Manuals Professional Edition|publisher=Merck Sharp & Dohme Corp.|accessdateaccess-date=23 October 2017}}</ref> It is considered severesignificant when levels are greater than 1.6 &nbsp;mmol/lL ( 5mg5&nbsp;mg/dldL).<ref name=Ron2008/>

Phosphates in blood exist in a [[chemical equilibrium]] of hydrogen phosphate (HPO₄^2–) and dihydrogen phosphate (H₂PO₄^–), which have different [[mass]]es. Phosphate (PO₄^3–) and [[phosphoric acid]] (H₃PO₄) are not present in significant amounts. Thus [[millimoles]] per liter (mmol/lL) are often used to denote the phosphate concententration. If milligrams per decililiter (mg/dldL) is used, it often denotes the ''mass of phosphorus'' bound to phosphates, but not the mass of some individual phosphate.<ref>{{Cite book|title=Nephrology secrets|vauthors=Lerma EV|year=2019|isbn=9780323478717|edition=4th|pages=532-533532–533|publisher=Elsevier |display-authors=etal}}</ref>

High phosphate levels can be avoided with [[phosphate binders]] and dietary restriction of phosphate.<ref name="Merck Manual Hyperphos" /> If the kidneys are operating normally, a saline diuresis can be induced to renally eliminate the excess phosphate. In extreme cases, the blood can be filtered in a process called [[hemodialysis]], removing the excess phosphate.<ref name="Merck Manual Hyperphos" /> Phosphate-binding medications include [[sevelamer]], [[lanthanum carbonate]], [[calcium carbonate]], and [[calcium acetate]].<ref>{{Cite book|title=Critical care nursing : diagnosis and management|date=2014|publisher=Elsevier/Mosby|others=Urden, Linda Diann.|isbn=978-0-323-09178-7|edition=7th|location=St. Louis, Mo.|pages=716|oclc=830669119}}</ref> Previously [[Aluminium hydroxide|aluminum hydroxide]] was the medication of choice, but its use has been largely abandoned due to the increased risk of [[Aluminium toxicity in people on dialysis|aluminum toxicity]].<ref>{{Cite journal|last1=Hutchison|first1=Alastair J.|last2=Smith|first2=Craig P.|last3=Brenchley|first3=Paul E. C.|date=October 2011|title=Pharmacology, efficacy and safety of oral phosphate binders|url=http://www.nature.com/articles/nrneph.2011.112|journal=Nature Reviews Nephrology|language=en|volume=7|issue=10|pages=578–589|doi=10.1038/nrneph.2011.112|pmid=21894188|s2cid=19833271|issn=1759-5061}}</ref>

[[Category:RTTWikipedia medicine articles ready to translate]]