Test Code OSMS Osmolality, Serum or plasma
Performing Laboratory
MaineGeneral Medical Center
Reference Values
275-295 mOsm/kg
Critical values (automatic call-back): <250 mOsm/kg or >320 mOsm/kg
Specimen Requirements
Serum Osmo
Draw blood in a serum gel tube(s). For pediatric specimen, draw blood in a red-top MICROTAINER(S)®. Spin down and send 1 mL of serum refrigerated.
Plasma Osmo
Draw blood in lithium heparin tube(s) (green top)
Note: Label specimen with patient’s name (first and last), date of birth, date and time of draw, and phlebotomist’s initials.
Day(s) Test Set Up
Monday through Sunday
Test Classification and CPT Coding
83930