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Introduction ⬇

Normally, the urinary chloride excretion approximates the dietary intake. The amount of chloride excreted in the urine in a 24-hour period is an indication of the state of electrolyte balance. Chloride is most often associated with sodium balance and fluid change.

The urine chloride measurement may be used to diagnose dehydration or as a guide in adjusting fluid and electrolyte balance in postoperative patients. It also serves as a means of monitoring the effects of reduced-salt diets, which are of great therapeutic importance in patients with cardiovascular disease, hypertension, liver disease, and kidney ailments.

Urine chloride is often ordered along with sodium and potassium as a 24-hour urine test. The urinary anion gap [(Na + K) − (Cl + HCO3)] is useful for initial evaluation of hyperchloremic metabolic acidosis. It is also used to determine whether a case of metabolic alkalosis is salt responsive.

Normal Findings ⬆ ⬇

Adult: 110–250 mEq/24 hr or 110–250 mmol/d

Child: 1–15 years old: 15–40 mEq/24 hr or 15–40 mmol/d

Child: 16–18 years old: 110–250 mEq/24 hr or 110–250 mmol/d

Values vary greatly with salt intake and perspiration.

Different laboratories may have different values. Test results are interpreted in relation to salt intake and output.

Procedure ⬆ ⬇

  1. Collect a 24-hour urine specimen.

  2. Record the exact starting and ending times on the specimen container and in the patient’s healthcare record.

  3. The complete specimen should be sent to the laboratory for refrigeration until it can be analyzed.

Clinical Alert

Because the electrolytes and water balance are so closely related, evaluate the patient’s state of hydration by checking daily weight, by recording accurate intake and output, and by observing and recording skin turgor, the appearance of the tongue and mucous membranes, and the appearance of the urine sample

Clinical Implications ⬆ ⬇

  1. Decreased urine chloride occurs in:

    1. Chloride-depleted patients (<10 mEq/L or <10 mmol/L); these patients have low serum chloride and are chloride responsive.

      1. SIADH secretion

      2. Vomiting, diarrhea, excessive sweating

      3. Gastric suction

      4. Addison disease

      5. Metabolic alkalosis

      6. Massive diuresis from any cause

      7. Villous tumors of the colon

    2. Chloride is decreased by endogenous or exogenous corticosteroids (>20 mEq/L or >20 mmol/L); this condition is not responsive to chloride administration. Diagnosis of a chloride-resistant metabolic alkalosis helps identify a corticotropin (adrenocorticotropic hormone [ACTH]) or aldosterone-producing neoplasm, such as:

      1. Cushing syndrome

      2. Conn syndrome

      3. Mineralocorticoid therapy

      4. Postoperative chloride retention

  2. Increased urine chloride occurs in:

    1. Increased salt intake

    2. Adrenocortical insufficiency

    3. Potassium depletion

    4. Bartter syndrome

    5. Salt-losing nephritis

Interventions ⬆ ⬇

Pretest Patient Care

  1. Explain purpose of test, procedure for 24-hour urine collection, and interfering factors.

  2. Follow guidelines in Chapter 1 for safe, effective, informed pretest care.

Posttest Patient Care

  1. Review test results; report and record findings. Modify the nursing care plan as needed. Monitor appropriately for fluid imbalances.

  2. Follow guidelines in Chapter 1 for safe, effective, informed posttest care.

Interfering Factors ⬆

  1. Decreased chloride is associated with:

    1. Carbenicillin therapy

    2. Reduced dietary intake of chloride

    3. Ingestion of large amounts of licorice

    4. Alkali ingestion

    5. Dehydration

  2. Increased chloride is associated with:

    1. Ammonium chloride administration

    2. Excessive infusion of normal saline

    3. Ingestion of sulfides, cyanides, halogens, bromides, and sulfhydryl compounds