Test Code (รหัสการทดสอบ):
Order Name (ชื่อการทดสอบ):
Osmolality (Random Urine)
Clinical Information (ข้อมูลทางคลินิก):
Osmolality is an index of the solute concentration. Urine osmolality is a measure of the concentration of osmotically active particles, principally sodium, chloride, potassium, and urea; glucose can contribute significantly to the osmolality when present in substantial amounts in urine. Urinary osmolality corresponds to urine specific gravity in nondisease states.
The ability of the kidney to maintain both tonicity and water balance of the extracellular fluid can be evaluated by measuring the osmolality of the urine either routinely or under artificial conditions. More information concerning the state of renal water handling or abnormalities of urine dilution or concentration can be obtained if urinary osmolality is compared to serum osmolality and if urine electrolyte studies are performed. Normally, the ratio of urine osmolality to serum osmolality is 1.0 to 3.0, reflecting a wide range of urine osmolality.
Reference Value (ค่าอ้างอิง):
|0 - 11 months
||50 - 750
|Over or equal 12 months
||150 - 1,150
With normal fluid intake and normal diet, a patient will produce a urine of about 500 to 850 mosmol/kg water. Above age of 20 years there is an age dependent decline in the upper reference range of approximately 5 mOsm/kg/year.
The normal kidney can concentrate a urine to 800 to 1,400 mosmol/kg and with excess fluid intake, a minimal osmolality of 40 to 80 mosmol/kg can be obtained.
With dehydration, the urine osmolality should be 3 to 4 times the plasma osmolality.
Clinical Reference (เอกสารอ้างอิง):
http://www.mayomedicallaboratories.com (Retrieved: 01 Jan 2019)