Bartter syndrome - Revision history

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Ostermayer: Created page with "Bartter syndrome is a group of rare autosomal recessive renal tubular disorders causing '''salt wasting from the thick ascending limb of the loop of Henle''', resulting in '''hypokalemic hypochloremic metabolic alkalosis''' with '''normal or low blood pressure'''.Bartter Syndrome. ''StatPearls''. NCBI. 2026. It mimics '''chronic loop diuretic use'''. The EM physician encounters Bartter syndrome as a '''severely dehydrated infant with refracto..."

2026-03-18T02:41:44Z

Created page with "Bartter syndrome is a group of rare autosomal recessive renal tubular disorders causing '''salt wasting from the thick ascending limb of the loop of Henle''', resulting in '''hypokalemic hypochloremic metabolic alkalosis''' with '''normal or low blood pressure'''.<ref name="StatPearls">Bartter Syndrome. ''StatPearls''. NCBI. 2026.</ref> It mimics '''chronic loop diuretic use'''. The EM physician encounters Bartter syndrome as a '''severely dehydrated infant with refracto..."

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Bartter syndrome is a group of rare autosomal recessive renal tubular disorders causing '''salt wasting from the thick ascending limb of the loop of Henle''', resulting in '''hypokalemic hypochloremic metabolic alkalosis''' with '''normal or low blood pressure'''.<ref name="StatPearls">Bartter Syndrome. ''StatPearls''. NCBI. 2026.</ref> It mimics '''chronic loop diuretic use'''. The EM physician encounters Bartter syndrome as a '''severely dehydrated infant with refractory hypokalemia''', a '''child with failure to thrive and electrolyte derangements''', or a '''known patient in crisis''' from intercurrent illness. The critical EM task is to '''recognize the electrolyte pattern, correct life-threatening hypokalemia, and avoid attributing the findings to vomiting or diuretic abuse'''.

==Background==
*Incidence ~1 in 1,000,000; much rarer than [[Gitelman syndrome]] (~1 in 25,000)
*'''Neonatal/antenatal Bartter:''' severe; presents in utero with polyhydramnios → premature birth → massive polyuria, dehydration, nephrocalcinosis within first weeks of life
*'''Classic Bartter:''' presents in infancy to school age with polyuria, polydipsia, failure to thrive, growth retardation
*Biochemically mimics '''chronic furosemide use''' — the transporter affected (NKCC2) is the same target as loop diuretics<ref name="StatPearls"/>
*'''Pseudo-Bartter syndrome''' can occur in cystic fibrosis (salt loss in sweat), chronic vomiting, or diuretic abuse — must be excluded

==Clinical Features==
*'''Polyuria and polydipsia''' (often severe; neonates may lose >10% body weight in first days)
*'''Dehydration''' — may be profound, especially with intercurrent illness (vomiting, diarrhea, fever)
*'''Failure to thrive, growth retardation'''
*'''Muscle weakness, cramps, fatigue''' (from hypokalemia)
*'''Constipation''' (from hypokalemia)
*'''Cardiac arrhythmias''' — potentially fatal; from severe hypokalemia ± hypomagnesemia; '''cardiac arrest has been reported'''<ref name="ERKNet">Konrad M, et al. Diagnosis and management of Bartter syndrome: consensus from ERKNet. ''Kidney Int''. 2021;99(2):324-338.</ref>
*'''Normal or low blood pressure''' despite high renin/aldosterone (distinguishes from other causes of hyperaldosteronism)
*Neonatal Bartter: history of '''polyhydramnios and premature birth'''
*Some subtypes: '''sensorineural deafness''' (type IV)
*'''Dysmorphic facies''' in some neonatal cases: triangular face, protruding ears, large eyes

==Differential Diagnosis==
*'''[[Gitelman syndrome]]:''' the most important differential — milder, presents later (adolescence/adulthood), has '''hypocalciuria and hypomagnesemia''' (Bartter has '''hypercalciuria''' and usually normal magnesium); mimics '''thiazide diuretic''' use rather than loop diuretic use

{| class="wikitable"
|-
! Feature !! '''Bartter syndrome''' !! '''[[Gitelman syndrome]]'''
|-
| Mimics || '''Loop diuretic''' (furosemide) || '''Thiazide diuretic''' (HCTZ)
|-
| Onset || Infancy/childhood (often neonatal) || Adolescence/adulthood
|-
| Severity || More severe; life-threatening dehydration || Milder; often incidental finding
|-
| Urine calcium || '''High''' (hypercalciuria → nephrocalcinosis) || '''Low''' (hypocalciuria)
|-
| Magnesium || Usually normal || '''Low''' (hypomagnesemia)
|}

*'''Surreptitious vomiting / bulimia:''' urine chloride '''<25 mEq/L''' (Bartter: '''urine chloride >35 mEq/L''') — this is the key distinguishing test
*'''Diuretic abuse:''' screen urine for diuretics
*'''Congenital adrenal hyperplasia''' (neonatal salt-wasting form) — hyperkalemia with salt wasting (opposite potassium direction from Bartter)
*'''Cystic fibrosis''' (pseudo-Bartter from sweat salt loss) — sweat chloride test
*'''Chronic laxative abuse'''
*'''Primary hyperaldosteronism''' — hypertension present (Bartter is normotensive/hypotensive)

==Evaluation==
===Workup===
*'''BMP:''' '''hypokalemia''' (may be severe, <2.5 mEq/L), '''hypochloremia''', '''metabolic alkalosis''' (elevated bicarbonate), normal or low sodium
*'''Magnesium:''' normal in most Bartter (low suggests Gitelman or type III Bartter)
*'''ABG/VBG:''' metabolic alkalosis
*'''Urine electrolytes:'''
**'''Urine chloride >35 mEq/L''' — confirms renal salt wasting (NOT vomiting)
**'''Urine potassium elevated''' — inappropriate renal potassium wasting
**'''Urine calcium:creatinine ratio elevated''' — hypercalciuria (classic Bartter); LOW in Gitelman
*'''Renin and aldosterone:''' both elevated (secondary hyperaldosteronism) — but blood pressure is '''not''' elevated
*'''ECG:''' assess for hypokalemia changes (flattened T waves, U waves, ST depression, prolonged QT, arrhythmias)
*'''Renal ultrasound:''' nephrocalcinosis (especially neonatal Bartter types I and II)

===Diagnosis===
*'''Hypokalemic hypochloremic metabolic alkalosis + elevated urine chloride (>35) + normal/low blood pressure + elevated renin/aldosterone''' = Bartter syndrome pattern
*Exclude vomiting (urine Cl <25), diuretic abuse (urine drug screen), and laxative abuse
*Genetic testing (SLC12A1, KCNJ1, CLCNKB, BSND, CASR) confirms subtype — not an ED test
*'''The diagnosis is clinical and biochemical''' — genetic confirmation follows

==Management==
*'''Correct hypokalemia — this is the EM priority'''
**'''IV potassium chloride''' for severe hypokalemia (K <2.5 mEq/L) or ECG changes or arrhythmias — '''use KCl, not other potassium salts''' (the chloride is needed to correct the concurrent hypochloremia and alkalosis)
**'''Oral potassium supplementation''' for mild-moderate hypokalemia
**'''Potassium replacement may be massive''' — these patients have ongoing renal losses; expect to give more than typical and monitor closely
**'''Correct hypomagnesemia''' if present (magnesium deficiency causes refractory hypokalemia)
*'''Aggressive IV fluid resuscitation''' with '''normal saline''' for dehydration — these patients are volume-depleted from renal salt wasting
*'''Cardiac monitoring''' — continuous telemetry if K <3.0 mEq/L or any ECG changes
*'''Continue home medications''' if the patient takes indomethacin, potassium supplements, or spironolactone — '''do NOT discontinue these'''
*'''Treat precipitating illness:''' intercurrent infection, GI illness, or any condition that worsens salt/water losses can precipitate acute crisis
*'''Do NOT use loop diuretics''' (furosemide) — this worsens the underlying defect
*'''Perioperative alert:''' patients with Bartter syndrome require careful electrolyte monitoring and IV potassium during surgery/anesthesia; alert anesthesia team if the patient presents for a procedure

==Disposition==
*'''Admit:'''
**Severe hypokalemia (K <2.5 mEq/L) or ECG changes/arrhythmias
**Severe dehydration requiring IV resuscitation
**Neonatal presentation (needs NICU; nephrology consultation)
**Unable to tolerate oral fluids and medications
*'''Discharge with close follow-up:'''
**Mild-moderate hypokalemia corrected with oral supplementation
**Tolerating PO fluids and home medications
**Stable hemodynamics
**Pediatric nephrology follow-up within days
*'''New diagnosis suspected''' (unexplained hypokalemic metabolic alkalosis in a young patient with renal potassium/chloride wasting and normal BP): arrange '''nephrology referral''' for confirmatory workup
*'''Counsel families:''' aggressive oral hydration is critical (especially during illness, hot weather, exercise); report symptoms of hypokalemia (weakness, cramps, palpitations, fainting) immediately

==See Also==
*[[Gitelman syndrome]]
*[[Hypokalemia]]
*[[Metabolic alkalosis]]
*[[Nephrolithiasis]]

==External Links==
*[https://www.ncbi.nlm.nih.gov/books/NBK442019/ StatPearls — Bartter Syndrome]
*[https://www.kidney-international.org/article/S0085-2538(20)31404-6/fulltext Kidney Int — Diagnosis and management of Bartter syndrome: ERKNet consensus (2021)]
*[https://pmc.ncbi.nlm.nih.gov/articles/PMC6233707/ PMC — Bartter syndrome: causes, diagnosis, and treatment (2018)]

==References==
<references/>

[[Category:Renal]]
[[Category:Pediatrics]]

← Older revision		Revision as of 09:31, 22 March 2026
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	*The critical EM task is to recognize the electrolyte pattern, correct life-threatening hypokalemia, and avoid attributing the findings to vomiting or diuretic abuse.		*The critical EM task is to recognize the electrolyte pattern, correct life-threatening hypokalemia, and avoid attributing the findings to vomiting or diuretic abuse.
	*Incidence ~1 in 1,000,000; much rarer than [[Gitelman syndrome]] (~1 in 25,000)		*Incidence ~1 in 1,000,000; much rarer than [[Gitelman syndrome]] (~1 in 25,000)
	*~~'''~~Neonatal/antenatal Bartter:~~'''~~ severe; presents in utero with polyhydramnios → premature birth → massive polyuria, dehydration, nephrocalcinosis within first weeks of life		*Neonatal/antenatal Bartter: severe; presents in utero with polyhydramnios → premature birth → massive polyuria, dehydration, nephrocalcinosis within first weeks of life
	*~~'''~~Classic Bartter:~~'''~~ presents in infancy to school age with polyuria, polydipsia, failure to thrive, growth retardation		*Classic Bartter: presents in infancy to school age with polyuria, polydipsia, failure to thrive, growth retardation
	*Biochemically mimics '''chronic furosemide use''' — the transporter affected (NKCC2) is the same target as loop diuretics<ref name="StatPearls"/>		*Biochemically mimics '''chronic furosemide use''' — the transporter affected (NKCC2) is the same target as loop diuretics<ref name="StatPearls"/>
	*'''Pseudo-Bartter syndrome''' can occur in cystic fibrosis (salt loss in sweat), chronic vomiting, or diuretic abuse — must be excluded		*'''Pseudo-Bartter syndrome''' can occur in cystic fibrosis (salt loss in sweat), chronic vomiting, or diuretic abuse — must be excluded
Line 18:		Line 18:
	*Cardiac arrhythmias — potentially fatal; from severe hypokalemia ± hypomagnesemia; '''cardiac arrest has been reported'''<ref name="ERKNet">Konrad M, et al. Diagnosis and management of Bartter syndrome: consensus from ERKNet. ''Kidney Int''. 2021;99(2):324-338.</ref>		*Cardiac arrhythmias — potentially fatal; from severe hypokalemia ± hypomagnesemia; '''cardiac arrest has been reported'''<ref name="ERKNet">Konrad M, et al. Diagnosis and management of Bartter syndrome: consensus from ERKNet. ''Kidney Int''. 2021;99(2):324-338.</ref>
	*Normal or low blood pressure despite high renin/aldosterone (distinguishes from other causes of hyperaldosteronism)		*Normal or low blood pressure despite high renin/aldosterone (distinguishes from other causes of hyperaldosteronism)
	*Neonatal Bartter: history of ~~'''~~polyhydramnios and premature birth~~'''~~		*Neonatal Bartter: history of polyhydramnios and premature birth
	*Some subtypes: ~~'''~~sensorineural deafness~~'''~~ (type IV)		*Some subtypes: sensorineural deafness (type IV)
	*Dysmorphic facies in some neonatal cases: triangular face, protruding ears, large eyes		*Dysmorphic facies in some neonatal cases: triangular face, protruding ears, large eyes

	==Differential Diagnosis==		==Differential Diagnosis==
	*[[Gitelman syndrome]]: the most important differential — milder, presents later (adolescence/adulthood), has ~~'''~~hypocalciuria and hypomagnesemia~~'''~~ (Bartter has ~~'''~~hypercalciuria~~'''~~ and usually normal magnesium); mimics ~~'''~~thiazide diuretic~~'''~~ use rather than loop diuretic use		*[[Gitelman syndrome]]: the most important differential — milder, presents later (adolescence/adulthood), has hypocalciuria and hypomagnesemia (Bartter has hypercalciuria and usually normal magnesium); mimics thiazide diuretic use rather than loop diuretic use

	{\| class="wikitable"		{\| class="wikitable"
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	\|}		\|}

	*Surreptitious vomiting / bulimia: urine chloride ~~'''~~<25 mEq/L~~'''~~ (Bartter: ~~'''~~urine chloride >35 mEq/L~~'''~~) — this is the key distinguishing test		*Surreptitious vomiting / bulimia: urine chloride <25 mEq/L (Bartter: urine chloride >35 mEq/L) — this is the key distinguishing test
	*Diuretic abuse: screen urine for diuretics		*Diuretic abuse: screen urine for diuretics
	*Congenital adrenal hyperplasia (neonatal salt-wasting form) — hyperkalemia with salt wasting (opposite potassium direction from Bartter)		*Congenital adrenal hyperplasia (neonatal salt-wasting form) — hyperkalemia with salt wasting (opposite potassium direction from Bartter)
Line 60:		Line 60:
	**Urine potassium elevated — inappropriate renal potassium wasting		**Urine potassium elevated — inappropriate renal potassium wasting
	**Urine calcium:creatinine ratio elevated — hypercalciuria (classic Bartter); LOW in Gitelman		**Urine calcium:creatinine ratio elevated — hypercalciuria (classic Bartter); LOW in Gitelman
	*Renin and aldosterone: both elevated (secondary hyperaldosteronism) — but blood pressure is ~~'''~~not~~'''~~ elevated		*Renin and aldosterone: both elevated (secondary hyperaldosteronism) — but blood pressure is not elevated
	*ECG: assess for hypokalemia changes (flattened T waves, U waves, ST depression, prolonged QT, arrhythmias)		*ECG: assess for hypokalemia changes (flattened T waves, U waves, ST depression, prolonged QT, arrhythmias)
	*Renal ultrasound: nephrocalcinosis (especially neonatal Bartter types I and II)		*Renal ultrasound: nephrocalcinosis (especially neonatal Bartter types I and II)
Line 71:		Line 71:

	==Management==		==Management==
	*~~'''~~Correct hypokalemia — this is the EM priority~~'''~~		*Correct hypokalemia — this is the EM priority
	**IV potassium chloride for severe hypokalemia (K <2.5 mEq/L) or ECG changes or arrhythmias — ~~'''~~use KCl, not other potassium salts~~'''~~ (the chloride is needed to correct the concurrent hypochloremia and alkalosis)		**IV potassium chloride for severe hypokalemia (K <2.5 mEq/L) or ECG changes or arrhythmias — use KCl, not other potassium salts (the chloride is needed to correct the concurrent hypochloremia and alkalosis)
	**Oral potassium supplementation for mild-moderate hypokalemia		**Oral potassium supplementation for mild-moderate hypokalemia
	**Potassium replacement may be massive — these patients have ongoing renal losses; expect to give more than typical and monitor closely		**Potassium replacement may be massive — these patients have ongoing renal losses; expect to give more than typical and monitor closely
	**Correct hypomagnesemia if present (magnesium deficiency causes refractory hypokalemia)		**Correct hypomagnesemia if present (magnesium deficiency causes refractory hypokalemia)
	*Aggressive IV fluid resuscitation with ~~'''~~normal saline~~'''~~ for dehydration — these patients are volume-depleted from renal salt wasting		*Aggressive IV fluid resuscitation with normal saline for dehydration — these patients are volume-depleted from renal salt wasting
	*Cardiac monitoring — continuous telemetry if K <3.0 mEq/L or any ECG changes		*Cardiac monitoring — continuous telemetry if K <3.0 mEq/L or any ECG changes
	*Continue home medications if the patient takes indomethacin, potassium supplements, or spironolactone — '''do NOT discontinue these'''		*Continue home medications if the patient takes indomethacin, potassium supplements, or spironolactone — '''do NOT discontinue these'''
Line 94:		Line 94:
	**Stable hemodynamics		**Stable hemodynamics
	**Pediatric nephrology follow-up within days		**Pediatric nephrology follow-up within days
	*New diagnosis suspected (unexplained hypokalemic metabolic alkalosis in a young patient with renal potassium/chloride wasting and normal BP): arrange ~~'''~~nephrology referral~~'''~~ for confirmatory workup		*New diagnosis suspected (unexplained hypokalemic metabolic alkalosis in a young patient with renal potassium/chloride wasting and normal BP): arrange nephrology referral for confirmatory workup
	*Counsel families: aggressive oral hydration is critical (especially during illness, hot weather, exercise); report symptoms of hypokalemia (weakness, cramps, palpitations, fainting) immediately		*Counsel families: aggressive oral hydration is critical (especially during illness, hot weather, exercise); report symptoms of hypokalemia (weakness, cramps, palpitations, fainting) immediately