Hypokloremæmi

Hypokloremæmi, also known as hypochloremia, is a medical condition defined by a serum chloride concentration below the normal range, typically around 98–106 mmol/L. Chloride is the major extracellular anion and helps maintain osmotic equilibrium, gas exchange, and acid-base balance, as well as contributing to gastric acid production.

Causes of hypochloremæmi include losses of chloride or reduced intake. Common etiologies are prolonged vomiting or gastric suction, which remove hydrochloric acid and deplete chloride; diuretic therapy (especially loop diuretics) and conditions causing renal chloride loss; excessive sweating with insufficient chloride intake; and certain renal or endocrine disorders that increase urinary chloride loss. Less commonly, extensive burns or fistulas may contribute.

Pathophysiology often involves a concomitant metabolic alkalosis, since chloride loss impairs renal bicarbonate excretion. This can sustain an alkalemic state even as volume depletion occurs. Correction typically requires restoring chloride and volume status, and addressing potassium abnormalities, as hypokalemia commonly accompanies hypochloremia and can worsen symptoms.

Clinical features are frequently subtle or absent in mild cases. When present, symptoms reflect metabolic alkalosis and electrolyte disturbances and may include weakness, irritability or confusion, muscle cramps, tetany, and, in severe cases, arrhythmias or seizures.

Diagnosis relies on laboratory testing showing low serum chloride, often with elevated bicarbonate and low or normal potassium. Urine chloride measurements can help distinguish renal from extrarenal causes: low urine chloride (<20 mmol/L) suggests extrarenal loss (e.g., vomiting), whereas higher urine chloride points to renal loss.

Management focuses on treating the underlying cause and restoring chloride and fluid balance. This is commonly done with isotonic saline, sometimes with potassium chloride added, while monitoring electrolytes and addressing any ongoing losses. prognosis depends on correcting the underlying condition and accompanying electrolyte abnormalities.