Hydration status and electrolyte levels must be assessed. Replacement of electrolytes with chloride salts is the most important mode of therapy for hypochloremic alkalosis. A full nutritional assessment should be obtained, energy intake calculated, and adequate energy intake ensured through oral or nasogastric methods.
Nonsteroidal anti-inflammatory drugs (NSAIDs; eg, indomethacin) are used in patients with Bartter syndrome. Hydrochloric acid (HCl) and carbonic anhydrase inhibitors (eg, acetazolamide) may be used in some acute situations. Potential complications of pharmacotherapy include the following:
Acetazolamide treatment compromising respiratory function in children with lung disease
Discharge medication instructions should be clearly written, and a supply sufficiently large to last until the patient is seen in the outpatient clinic should be prescribed.
Medical Correction of Hypochloremic Alkalosis
Acute emergency management (6 hours or less)
Initial management includes assessment of dehydration status and severity of hypochloremia, hypokalemia, hyponatremia, and metabolic alkalosis. If the patient is in shock, treatment should be directed toward aggressive resuscitation with isotonic fluid, preferably normal saline. Blood and urine samples for testing of electrolytes should always be obtained before any form of therapy is initiated; this is of great help in differentiating etiologic factors in new cases.
Chronic acid-base disturbances must not be treated too rapidly; more serious complications may be prevented by meticulous and slow correction. For example, consider the case of a child whose initial blood work shows the following results:
Sodium 120 mmol/L
Potassium 2 mmol/L
Chloride 80 mmol/L
Bicarbonate 40 mmol/L
In this child, assessment of cardiac function is indicated. If there is no dysrhythmia, rapid correction of this severe hypokalemia is unnecessary. Administration of 5% dextrose in 0.9 isotonic sodium chloride solution plus potassium chloride 20 mEq/L at a maintenance rate can be a safe measure.
Maintenance management (7-72 hours)
Maintenance therapy depends on how much improvement occurred after 6 hours of initial fluid and electrolyte administration. The aim is to increase the serum potassium concentration very slowly as the serum bicarbonate level drops. This helps prevent a sharp increase in serum potassium concentration and its subsequent detrimental effects on cardiac conductivity.
Long-term management (after 72 hours)
For long-term management, intravenous (IV) fluids can be discontinued. The physician should calculate the average daily amounts of chloride, sodium, and potassium that were required to correct the serum electrolyte levels. The total amounts can then be administered orally in 3-4 divided doses per day. In most patients, the average chloride dose required is 4-10 mEq/kg/day in the form of sodium and potassium salts.
Other management procedures depend on the primary cause of hypochloremic alkalosis.
Surgical or Endoscopic Intervention
Surgical intervention is usually unnecessary. If ileus is suspected in a child with severe hypokalemia, the appropriate treatment is administration of potassium chloride, not surgical intervention. However, if the cause of hypochloremic alkalosis is an upper gastrointestinal (GI) tract abnormality, such as gastroesophageal reflux or pyloric stenosis, surgical or endoscopic intervention is indicated.
Kilojoule intake should be appropriate for the patient’s catabolic status, usually 100-150% of the recommended daily allowance (RDA). Additional protein should be ingested to prevent malnutrition. Fat requirements depend on the individual patient. For example, patients with cystic fibrosis have special dietary needs that should be met.
Multivitamins and hematinic agents should be provided as required. Supplemental trace elements (eg, zinc) should be provided to patients with a trace-element deficiency, such as some patients with chloride-losing diarrhea (CLD). High sodium and potassium diets are required for all children with chronic metabolic alkalosis secondary to Bartter syndrome or CLD.
Normal activity should be recommended for children with hypochloremic alkalosis unless central nervous system (CNS) damage is severe, in which case special restrictions are required.
Children with refractory severe hypokalemia should avoid extended exposure to heat, especially in hot climates. Exposure to heat may cause dehydration and may exacerbate the condition.
In patients with CLD, fluid intake should be encouraged so as to prevent renal damage resulting from recurrent dehydration. Patients or caregivers should be instructed to avoid long periods of exposure to hot climates, which may exacerbate dehydration episodes.
Constipation must be treated in patients with Bartter syndrome. Any intercurrent febrile illnesses, especially urinary tract infections, must be treated to prevent further renal damage.
The following may be consulted as necessary:
Pediatric nephrologist (in all cases)
Pediatric endocrinologist (to exclude other causes of growth failure)
Patients should receive regular follow-up examinations by a physician and nurse clinician. Such examinations should take place at least once every month in infants but may be less frequent in older children and children who are more stable.
The preclinic laboratory workup includes a biochemical profile and monitoring of urine electrolytes. The pharmacotherapeutic regimen should be reviewed at each visit. Medications should be refilled and dosages adjusted in accordance with the patient’s clinical status and laboratory results.
Diagnostic imaging studies should be repeated as necessary. For example, kidney ultrasonography may be needed to assess the degree of nephrocalcinosis in children with Bartter syndrome.
Growth parameters should be assessed, and the question of whether growth hormone therapy is needed should be evaluated in consultation with a pediatric endocrinologist. Renal function should be assessed, and every effort should be made to minimize the use of nephrotoxic agents if possible.
Patients with chronic diseases, such as Bartter syndrome, chloride-losing diarrhea (CLD), and cystic fibrosis, should have lifelong follow-up care.
Future pregnancies in women with a child with hypochloremic alkalosis should be monitored in a tertiary care center so that early diagnosis and intervention are available at delivery.
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