Laboratory Medicine
Test Directory / Urine Sodium
Urine Sodium
24 hour container, urine monovette or white topped universal (no additives)
| Test | Urine Sodium |
|---|---|
| Common Abbreviations | USOD, USODR |
| Profile | Urine Urea and Electrolytes |
| Tube type | 24 hour container, urine monovette or white topped universal (no additives) |
| Clinical Indication | Urinary sodium, together with assessment of volume status, is useful in the differential diagnosis of hyponatramia. Urinary sodium levels are also frequently ordered during the workup of acute renal failure with the fractional excretion of sodium used as an important marker in distinguishing pre-renal from post-renal failure. A urinary sodium of <20mmol/L in a dehydrated patient is consistentwith functional renal tubules which will respond to rehydration whilst a urinary sodium of >20mmol/L (typically >50mmol/L) in conjunction with a low/normal urea and/or urate is indicative of SIADH. It is also used to monitor compliance with a low salt diet in hypertensive patients. |
| Specimen Type | Urine |
| Sample type | Random or 24 Hour Urine |
| Minimum Volume | 1mL |
| Special Precautions | No special requirements |
| Stability | 45 days at 2-25°C |
| Turnaround Time | Inpatient: 6 hours Outpatient/ GP: 24 hours |
| Laboratory | York and Scarborough |
| Reference Interval | 40 - 250 mmol/24hours Reference range for random urine not available. Result should be interpreted in conjunction with serum result. |
| Limitations | NA |
| Notes |
