Indication of fluid balance and acid-base homeostasis using a 24-hour urine collection
Potentiometric, Indirect Ion-Selective Electrode (ISE)
Cl (Chloride) Urine
Electrolytes
Lytes
Urine
24-Hour volume (in milliliters) is required.
Question ID | Description | Answers |
---|---|---|
TM30 | Collection Duration | |
VL28 | Urine Volume |
Supplies: Sarstedt 5 mL Aliquot Tube (T914)
Collection Container/Tube: 24-Hour graduated urine container with no metal cap or glued insert
Submission Container/Tube: Plastic, 5 mL tube or a clean, plastic aliquot container with no metal cap or glued insert
Specimen Volume: 4 mL
Collection Instructions:
1. Collect urine for 24 hours.
2. Refrigerate specimen within 4 hours of completion of 24-hour collection.
Additional Information:
If not ordering electronically, complete, print, and send a Renal Diagnostics Test Request (T830) with the specimen.
Note: The addition of preservative or application of temperature controls must occur within 4 hours of completion of the collection.
Ambient | OK |
Refrigerate | Preferred |
Frozen | OK |
50% Acetic Acid | OK |
Boric Acid | OK |
Diazolidinyl Urea | OK |
6M Hydrochloric Acid | No |
6M Nitric Acid | No |
Sodium Carbonate | OK |
Thymol | OK |
Toluene | No |
1 mL
Specimen Type | Temperature | Time | Special Container |
---|---|---|---|
Urine | Refrigerated (preferred) | 14 days | |
Frozen | 30 days | ||
Ambient | 7 days |
Indication of fluid balance and acid-base homeostasis using a 24-hour urine collection
Chloride is the major extracellular anion. Its precise function in the body is not well understood; however, it is involved in maintaining osmotic pressure, proper body hydration, and electric neutrality. In the absence of acid-base disturbances, chloride concentrations in plasma will generally follow those of sodium.
Since urine is the primary mode of elimination of ingested chloride, urinary chloride excretion during steady state conditions will reflect ingested chloride, which predominantly is in the form of sodium chloride. However, under certain clinical conditions, the renal excretion of chloride may not reflect intake. For instance, during states of extracellular volume depletion, urine chloride (and sodium) excretion is reduced.
> or =18 years: 34-286 mmol/24 hours
Reference values have not been stablished for patients who are less than 18 years of age.
Reference values apply to 24-hour collection.
Urine sodium and chloride excretion are similar, and, under steady-state conditions, both the urinary sodium and chloride excretion reflect the intake of sodium chloride. During states of extracellular volume depletion, low values indicate appropriate renal reabsorption of these ions, whereas elevated values indicate inappropriate excretion (renal wasting). Urinary sodium and chloride excretion may be dissociated during metabolic alkalosis with volume depletion where urine sodium excretion may be high (due to renal excretion of sodium bicarbonate), while urine chloride excretion remains appropriately low.
High urine values of other halide ions (eg, bromide, fluoride, iodide) may lead to falsely high readings on the chloride ion-selective electrode.
1. Delaney MP, Lamb EJ: Kidney disease. In: Rifai N, Horvath AR, Wittwer CT, eds: Tietz Textbook of Clinical Chemistry and Molecular Diagnostics. 6th ed. Elsevier; 2018:1308-1309
2. Kamel KS, Ethier JH, Richardson RM, Bear RA, Halperin ML: Urine electrolytes and osmolality: when and how to use them. Am J Nephrol. 1990;10(2):89-102
The ion-selective electrode (ISE) module performs indirect measurement of electromotive force (EMF). The ISE module measures the EMF difference between an ion-selective electrode and a reference electrode. The EMF of the ion-selective electrode is dependent on the ion concentration of the sample. The EMF of the reference electrode is constant. An electronic calculation circuit converts EMF of the sample to the ion concentration of the sample.(Package insert: ISE. Roche Diagnostics; V14.0 02/2018)
Monday through Sunday
This test has been cleared, approved, or is exempt by the US Food and Drug Administration and is used per manufacturer's instructions. Performance characteristics were verified by Mayo Clinic in a manner consistent with CLIA requirements.
82436
Test Id | Test Order Name | Order LOINC Value |
---|---|---|
CLU | Chloride, 24 HR, U | 43128-8 |
Result Id | Test Result Name |
Result LOINC Value
Applies only to results expressed in units of measure originally reported by the performing laboratory. These values do not apply to results that are converted to other units of measure.
|
---|---|---|
CL24H | Chloride, 24 HR, U | 2079-2 |
TM30 | Collection Duration | 13362-9 |
VL28 | Urine Volume | 3167-4 |