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'''Milk-alkali syndrome''' is [[hypercalcemia]] caused by repeated ingestion of [[calcium]] and absorbable [[alkali]] (such as [[calcium carbonate]], or [[milk]] and [[sodium bicarbonate]]).  If untreated, '''milk-alkali syndrome''' may lead to metastatic calcification and [[renal failure]].   
{{Infobox_Disease |
  Name          = {{PAGENAME}} |
  Image          = |
  Caption        = |
  DiseasesDB    = 8215 |
  ICD10          = |
  ICD9          = {{ICD9|275.42}} |
  ICDO          = |
  OMIM          = |
  MedlinePlus    = 000332 |
  eMedicineSubj  = med |
  eMedicineTopic = 1477 |
  MeshID        = |
}}
In [[medicine]], '''milk-alkali syndrome''', also called Burnett's syndrome in honour of the American physician who first described it, is characterized by [[hypercalcemia]] caused by repeated ingestion of [[calcium]] and absorbable [[alkali]] (such as [[calcium carbonate]], or [[milk]] and [[sodium bicarbonate]]).  If untreated, '''milk-alkali syndrome''' may lead to [[metastatic calcification]] and [[renal failure]].   


'''Pathophysiology'''<br />
It was most common in the early 20th century, but there has been a recent increase in the number of cases reported.<ref name="pmid17483976">{{cite journal |author=Caruso JB, Patel RM, Julka K, Parish DC |title=Health-behavior induced disease: return of the milk-alkali syndrome |journal=J Gen Intern Med |volume=22 |issue=7 |pages=1053–5 |year=2007 |month=July |pmid=17483976 |doi=10.1007/s11606-007-0226-0 |url=http://dx.doi.org/10.1007/s11606-007-0226-0}}</ref><ref name="pmid16702792">{{cite journal |author=Beall DP, Henslee HB, Webb HR, Scofield RH |title=Milk-alkali syndrome: a historical review and description of the modern version of the syndrome |journal=Am. J. Med. Sci. |volume=331 |issue=5 |pages=233–42 |year=2006 |month=May |pmid=16702792 |doi= |url=http://meta.wkhealth.com/pt/pt-core/template-journal/lwwgateway/media/landingpage.htm?an=00000441-200605000-00001}}</ref>
Ingestion of over 2g of elemental [[calcium]] per day may lead to this disorder.  When a large quantity of [[calcium]] is ingested and absorbed by the GI tract, [[hypercalcemia]] works to feedback on the [[parathyroid gland]] to inhibit production of [[PTH]]. This, in turn, leads to an increased absorption of [[bicarbonate]] in the [[kidney]], establishing [[metabolic alkalosis]].  Additionally, [[hypercalcemia]] produces a concentrating defect in the [[kidney]] which can be considered a form of nephrogenic [[diabetes insipidus]].


'''Clinical'''<br />
==Pathophysiology==
Effects due to [[hypercalcemia]] may be remembered by ''bones'', ''stones'', ''groans'' and ''psychiatric undertones''This means an increased risk of [[Kidney stones]], [[bone fractures]], [[anorexia (symptom)|anorexia]], [[vomiting]], [[constipation]] and a host of psychiatric effects, including weakness, fatigue and [[altered mental status]].  Thus, a level of [[serum]] [[calcium]] must be obtained, but a full workup must include total/ionized [[calcium]], [[human serum albumin|albumin]], [[phosphate]], [[PTH]], [[PTHrP]], [[vitamin D]] and [[TSH]].  In addition, evaluation of [[hypercalcemia]] must include an [[ECG]], which may show a short QT interval.<br />
The name "milk-alkali syndrome" derives from when patients would take in excessive amounts of milk and antacids to control their dyspepsia, leading to overingestion of two key ingredients that lead to the disorder, excess calcium and excess baseIngesting over two grams of elemental [[calcium]] per day produces this disorder in susceptible individuals. [[Gastrointestinal tract|Gastrointestinal]] absorption of such a large amount of calcium leads to [[hypercalcemia]].  This inhibits [[parathyroid hormone]] secretion by the [[parathyroid gland]] and may also lead to [[diabetes insipidus]].  The body's attempt to rid itself of the excess base in the urine may cause bicarbonaturia and subsequent hypovolemia due to transport of sodium ions to accompany the bicarbonate.


'''REFERENCES'''<br />
Hypovolemia may increase the reabsorption of calcium and [[bicarbonate]] in the [[proximal convoluted tubule]]s of the kidney. Elevated bicarbonate levels in the blood raises the [[pH]], producing an [[alkalemia]]. In this state, excess bicarbonate eventually begins to reach the [[distal convoluted tubule]], leading to sodium retention in the lumen, an effect similar to the action of [[thiazide]] diuretics, hence increasing lumen positivity and driving calcium through the passive calcium channels to bind intracellular [[calbindin]]. Finally, because of the decreased intracellular sodium, there is an increased driving force for the basolateral Na+/Ca++ antiporter, thus facilitating calcium reabsorption. Basically, hypovolemia is the culprit that prevents correction of the hypercalcemia.
----
1. eMedicine.com - Milk-Alkali Syndrome ([http://www.emedicine.com/med/topic1477.htm]).


{{WikiDoc Sources}}
The understanding of this mechanism led to the development of a simple yet elegant treatment for hypercalcemia. The first and most important step is [[Route of administration#Parenteral by injection or infusion|intravenous infusion]] of [[Saline (medicine)|normal saline]] to restore the intravascular volume, which reverses the calcium and bicarbonate retention in the PCT. Then a [[loop diuretic]] is used, but only after the volume replacement is complete, otherwise volume contraction would result, which would further exacerbate the hypercalcemia. The loop diuretics inhibit the [[Na-K-2Cl symporter]] and hence eliminate passive diffusion of potassium into the lumen via the [[ROMK]] channel. This effectively removes the net positive charge from the lumen, one of the main driving forces for calcium reabsorption via the paracellular pathway. In addition, loop diuretics increase the flow of luminal contents, which helps flush the calcium to the distal nephron.
 
==Clinical==
Effects due to [[hypercalcemia]] may be remembered by ''bones'', ''stones'', ''groans'' and ''psychiatric overtones''.  This means an increased risk of [[kidney stones]], [[bone fractures]], [[anorexia (symptom)|anorexia]], [[vomiting]], [[constipation]] and a host of psychiatric effects, including weakness, fatigue and [[altered mental status]].  Thus, a level of [[serum]] [[calcium]] must be obtained, but a full workup must include total/ionized [[calcium]], [[human serum albumin|albumin]], [[phosphate]], [[PTH]], [[PTHrP]], [[vitamin D]] and [[TSH]].  In addition, evaluation of [[hypercalcemia]] must include an [[ECG]], which may show a short QT interval.
 
==Eponym==
It is named for [[Charles Hoyt Burnett]].<ref>{{WhoNamedIt|synd|4029}}</ref><ref>{{cite journal |author=Burnett CH, Commons RR, Albright F, Howard JE |title=Hypercalcemia without hypercalcuria or hypophosphatemia, calcinosis and renal insufficiency; a syndrome following prolonged intake of milk and alkali |journal=N. Engl. J. Med. |volume=240 |issue=20 |pages=787–94 |year=1949 |pmid=18126919 |doi= |url=}}</ref>
 
==References==
{{reflist}}
 
==External links==
* eMedicine.com - Milk-Alkali Syndrome ([http://www.emedicine.com/med/topic1477.htm]).
 
[[Category:Electrolyte disturbances]]
[[Category:Calcium]]
[[Category:Urinary system]]
[[Category:Diseases and disorders]]
[[Category:Kidney diseases]]
[[Category:Urology]]
 
{{Mineral metabolic pathology}}
 
[[de:Burnett-Syndrom]]

Revision as of 19:55, 9 January 2009

Milk-alkali syndrome
ICD-9 275.42
DiseasesDB 8215
MedlinePlus 000332
eMedicine med/1477 

In medicine, milk-alkali syndrome, also called Burnett's syndrome in honour of the American physician who first described it, is characterized by hypercalcemia caused by repeated ingestion of calcium and absorbable alkali (such as calcium carbonate, or milk and sodium bicarbonate). If untreated, milk-alkali syndrome may lead to metastatic calcification and renal failure.

It was most common in the early 20th century, but there has been a recent increase in the number of cases reported.[1][2]

Pathophysiology

The name "milk-alkali syndrome" derives from when patients would take in excessive amounts of milk and antacids to control their dyspepsia, leading to overingestion of two key ingredients that lead to the disorder, excess calcium and excess base. Ingesting over two grams of elemental calcium per day produces this disorder in susceptible individuals. Gastrointestinal absorption of such a large amount of calcium leads to hypercalcemia. This inhibits parathyroid hormone secretion by the parathyroid gland and may also lead to diabetes insipidus. The body's attempt to rid itself of the excess base in the urine may cause bicarbonaturia and subsequent hypovolemia due to transport of sodium ions to accompany the bicarbonate.

Hypovolemia may increase the reabsorption of calcium and bicarbonate in the proximal convoluted tubules of the kidney. Elevated bicarbonate levels in the blood raises the pH, producing an alkalemia. In this state, excess bicarbonate eventually begins to reach the distal convoluted tubule, leading to sodium retention in the lumen, an effect similar to the action of thiazide diuretics, hence increasing lumen positivity and driving calcium through the passive calcium channels to bind intracellular calbindin. Finally, because of the decreased intracellular sodium, there is an increased driving force for the basolateral Na+/Ca++ antiporter, thus facilitating calcium reabsorption. Basically, hypovolemia is the culprit that prevents correction of the hypercalcemia.

The understanding of this mechanism led to the development of a simple yet elegant treatment for hypercalcemia. The first and most important step is intravenous infusion of normal saline to restore the intravascular volume, which reverses the calcium and bicarbonate retention in the PCT. Then a loop diuretic is used, but only after the volume replacement is complete, otherwise volume contraction would result, which would further exacerbate the hypercalcemia. The loop diuretics inhibit the Na-K-2Cl symporter and hence eliminate passive diffusion of potassium into the lumen via the ROMK channel. This effectively removes the net positive charge from the lumen, one of the main driving forces for calcium reabsorption via the paracellular pathway. In addition, loop diuretics increase the flow of luminal contents, which helps flush the calcium to the distal nephron.

Clinical

Effects due to hypercalcemia may be remembered by bones, stones, groans and psychiatric overtones. This means an increased risk of kidney stones, bone fractures, anorexia, vomiting, constipation and a host of psychiatric effects, including weakness, fatigue and altered mental status. Thus, a level of serum calcium must be obtained, but a full workup must include total/ionized calcium, albumin, phosphate, PTH, PTHrP, vitamin D and TSH. In addition, evaluation of hypercalcemia must include an ECG, which may show a short QT interval.

Eponym

It is named for Charles Hoyt Burnett.[3][4]

References

  1. Caruso JB, Patel RM, Julka K, Parish DC (2007). "Health-behavior induced disease: return of the milk-alkali syndrome". J Gen Intern Med. 22 (7): 1053–5. doi:10.1007/s11606-007-0226-0. PMID 17483976. Unknown parameter |month= ignored (help)
  2. Beall DP, Henslee HB, Webb HR, Scofield RH (2006). "Milk-alkali syndrome: a historical review and description of the modern version of the syndrome". Am. J. Med. Sci. 331 (5): 233–42. PMID 16702792. Unknown parameter |month= ignored (help)
  3. Template:WhoNamedIt
  4. Burnett CH, Commons RR, Albright F, Howard JE (1949). "Hypercalcemia without hypercalcuria or hypophosphatemia, calcinosis and renal insufficiency; a syndrome following prolonged intake of milk and alkali". N. Engl. J. Med. 240 (20): 787–94. PMID 18126919.

External links

  • eMedicine.com - Milk-Alkali Syndrome ([1]).

Template:Mineral metabolic pathology

de:Burnett-Syndrom