Interpretation
In normal health, urine chloride output largely reflects intake.
Urine chloride is a constituent of the urine anion gap which can be used to differentiate between the causes of a normal anion gap metabolic acidosis.
Urine chloride is also measured when investigating a patient with a hypochloraemic metabolic alkalosis. A low urinary chloride (typically <10mmol/L) in this setting indicates appropriate renal chloride retention and is suggestive of a gastrointestinal cause of the alkalosis (e.g. prolonged vomiting). However an elevated urine chloride in a patient with a metabolic alkalosis suggests renal chloride wasting which may be due to conditions such as mineralocorticoid excess or a primary disorder of the renal tubules.
Reference Intervals
Timed 24 hr urine: 110 – 250 mmol/24hr
Test Method
Indirect ion specific electrode (ISE) performed on Beckman Coulter AU5822 analysers.