From the Guidelines
Diagnosing acquired Bartter syndrome requires a comprehensive approach that prioritizes clinical evaluation, laboratory tests, and exclusion of other causes, with a focus on identifying characteristic electrolyte abnormalities and elevated renin and aldosterone levels 1. To diagnose acquired Bartter syndrome, the following steps should be taken:
- Evaluate the patient's medical history, including any history of polyhydramnios, premature birth, growth failure, and family history 1
- Conduct biochemical tests, including serum electrolytes (sodium, chloride, potassium, calcium, magnesium), acid-base status, renin, aldosterone, creatinine, fractional excretion of chloride, and urinary calcium-creatinine ratio 1
- Perform a renal ultrasound to detect medullary nephrocalcinosis and/or kidney stones 1
- Consider genetic analysis to confirm the clinical diagnosis of Bartter syndrome, although this is not typically necessary for acquired forms 1 Key laboratory findings in acquired Bartter syndrome include:
- Hypokalemia
- Metabolic alkalosis
- Normal to low blood pressure despite elevated renin and aldosterone levels
- Increased potassium, sodium, and chloride excretion in the urine It is essential to exclude other causes of similar electrolyte imbalances, such as vomiting, diuretic abuse, and other tubulopathies 1. A thorough medication history is crucial, as acquired Bartter syndrome is often medication-induced, with a focus on diuretics, aminoglycosides, cisplatin, and other nephrotoxic drugs 1.
From the Research
Diagnosis of Acquired Bartter Syndrome
To diagnose acquired Bartter syndrome, the following steps can be taken:
- Identify the clinical presentation, which may include polyuria, polydipsia, vomiting, and dehydration 2, 3
- Perform laboratory tests to check for hypokalemic metabolic alkalosis, hypochloremia, and hypercalciuria 4, 5
- Check for genetic variants, although this may not be necessary for diagnosis as the phenotype-genotype relationship is poor 4
- Consider the patient's medical history and physical examination to rule out other possible causes of the symptoms 3
Laboratory Tests
Laboratory tests that can be used to diagnose acquired Bartter syndrome include:
- Electrolyte panel to check for hypokalemia, hypochloremia, and metabolic alkalosis 2, 3
- Urinalysis to check for hypercalciuria and proteinuria 5
- Renal function tests to check for impaired renal function 4
- Genetic testing to identify mutations in genes associated with Bartter syndrome, although this is not always necessary for diagnosis 2, 5
Clinical Findings
Clinical findings that can be used to diagnose acquired Bartter syndrome include: