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UW Health SMPH
American Family Children's Hospital

UW Hospital and Clinics Lab Test Directory

Test Name: Osmolality

Test Code(s): SOSM / GM2215

CPT Code(s): 83930

Methodology: Freezing Point Osmometer

Days Performed: Daily, 24 hours.

Turnaround Time: Stat: 1 hour.
Routine: 4 hours.


Specimen Requirements

Specimen: Blood

Collection Container: Preferred: Red cap with yellow ring (SST)
Also Acceptable: Green cap with yellow ring (PST), Green top, Red top

Collection Volume: Preferred: 2 mL
Pediatrics: 1 mL

Sample Analyzed: Serum or plasma

Volume Required: Preferred: 1 mL
Pediatrics: 0.5 mL

Specimen Processing: Centrifuge.  If a complete barrier has not formed, transfer cell-free serum/plasma to plastic vial.  Refrigerate.

Specimen Transport: Transport specimen to UWHC Core Laboratory (B4/220). Transport with coolant pack if coming from outreach location.

Stability: Ambient: 48 hours
Refrigerated: 48 hours


Interpretation

Reference Interval:
Age:  mOsm/kg
0 days to 30 days  266-298
31 days and up  278-298

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